Structural Collapse Technician Training-Ver. 3.1

Structural Collapse Technician Training-Ver. 3.1
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Structural Collapse Technician Training-Ver. 3.1 Module : 2a Shoring Basics Jul12 Note the following Changes/Additions to 2012 version: Added info on SOG3 & FOG7 on Slide 5 Added Slide 25 – Shore Nomenclature (similar to what is in Sect 2b Slide 34 – new wording for Vert Shore w/ minimum gussets Slide 35 – new wording for fully braced vert shore Slides 51 & 52- Window Shore – changed Triangle to Half-Gusset, discontinue Triangle Slide 53 – new photos of Window Shores Slide 54 – some new wording for LP Slide 59 & 60 – new Plywood Laced Posts (PLP) in 4ft x 4ft & 2ft x 4ft configurations. Slide 84, 86 –89 added wording for sloped fl shore plus new photos + wedges at Type 3 Slides 97 & 98 – expanded discussion regarding the uses for Sloped Floor Shores, and added data on how to determine the Design Load . Consult a Structures Specialist. Slide 100 – Horiz Shore: changed Triangle to Half-Gusset, discontinue Triangle . Slide 104 – added wording and note Insertion Point Slide 109 – Friction Shore, fix backing & words – omit U-channel Slide 110 – The U-Channel Base has been discontinued, due to need to dig-in. Slide 111 & 114 add backing to Solid & Split Sole Rakers Slide 121 – Pneumatic Raker – add note to add mid-brace over 11ft Slide 122 – shows photo of new mid-braced raker by Hurst/Airshore. Slide 123, ,129– add note to use 10k/pair of rakers if mid-brace is installed Slide 126 – shows photos of three new configurations of Paratech Strut Rakers. Slide 141 – add not regarding not as pronounced signs of failure for Southern Pine. Jun 2012

Basic Definition Terminal Objectives
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Terminal Objectives The Student shall understand the function & capacity of the Shoring used in US&R to support damaged structures The Student should also understand why and how these Shores are constructed Basic Definition Shoring for US&R is the TEMPORARY Support of Only That Part of a Damaged Structure that is REQUIRED for Conducting Operations at REDUCED RISK Best not to read slide Encourage questions by class members Remember to repeat all questions, especially in large classes Jun 2012

FEMA US&R Response System Structural Collapse Technician Training
Module 2a Shoring Basics Instructors Slides + Notes Key Learning Points - 1 What is Size and Type of Load that needs to be supported? The weight of the supporting structure plus its overload, or just its overload Broken Structure or Rigid Structure How much Shoring do you need? Should Shoring be similar to a Life Jacket? – providing just enough lift to keep one afloat Some portion of the load can be (is being) carried by the un-shored structure These are more Struct Spec Issues, but Rescue should understand as well These are the KEY Issues regarding How Much Shoring Jun 2012

Module 2a Shoring Basics Instructors Slides + Notes Key Learning Points - 2 What is the Capacity for the various types of US&R Shoring Systems? How to configure US&R Shoring to ensure a predictable & slow Failure Mode How to sequence the construction of US&R shoring in order to Minimize Risk What are initial, short-term systems What are more long-term systems What are Class 1, 2, & 3 Systems What is sequence in Multi-Story Shoring? How and When to Inspect US&R Shoring These are more Struct Spec Issues, but Rescue needs to understand as well These are the KEY Issues for Construction and Inspection Jun 2012

USACE FOG & SOG Sect 1-9 Sect 1-4
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Sect 1 Haz ID + Marking Sys Sect 2 Vert Shoring Sect 3 Lateral Shoring Sect 4 Repair Techniques FAQ & Glossary SOG has added Eng Tables Sect 5 Equip Ops Procedures Sect 6 Reference Data Sect 7 Engineering Tables Sect 8 USACE StS Deployment Ck-Lists Sect 9 FEMA StS Deployment Ck-Lists & Forms USACE FOG & SOG Discuss the Use of the StS FOG & the SOG The SOG has fewer pages, and is most useful for Rescue Spec The first 4 section of both publications are similar. The FOG has added info that is most useful for Struct Spec. The SOG has some engineering tables added to Sect 4 The current versions of the SOG & FOF are SOG3 and FOG7 Sections 2 & 3 have been redone for both with mostly new graphics. Sect 4 has new info on Repair Techniques for Damaged Structures. Sect 5 has updated info on operation of newer devices Sect 9 has updated StS Forms Inform students that free electronic copies of both may be obtained from Disasterengineer.org – in Library. Printed copies may be purchased from RescueDirect.com for cost + about $0.50 Sect 1-9 Sect 1-4 Jun 2012

Double Funnel Principle
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Double Funnel Principle Collect Load Distribute Load Need Posts / Shores with Adjustability & Positive Connections Need Lateral Bracing Need System with Forgiveness Difficult, if not impossible to combine Positive Connections & Good Bracing and still have Adjustability Jun 2012

Weights of Building Materials
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Weights of Building Materials Reinforced concrete = 150 pcf Concrete columns & beams weigh more (16"sq w/ 5% rebar = 170pcf) Masonry = 125 pcf Wood = 35 pcf (dry) Steel = 490 pcf Concrete or masonry rubble = 10 psf per inch Debris may weigh a lot less than 10 psf per inch, especially if they contain lots of softer materials Note that heavily reinforced concrete beams and columns could weigh as much as 200pcf Some may wish to use weight of a cubic inch of concrete or steel, so that is given for cases when one is making measurements in inches and does not want to convert to cubic feet Next slide gives a quick method for calculating weights of concrete slabs, walls and combos of rectangular pieces, by using the weight per square foot of various thickness. Also may be used for steel plates and shapes Jun 2012

Module 2a Shoring Basics Instructors Slides + Notes Quick way to estimate weights Base estimate on approximate weight per square foot for unit thickness of concrete (12") and steel (1") 12" conc slab = 150 psf 10' conc slab = 125psf 8" conc slab = 100psf 6" conc slab = 75psf (and so on) 1" steel plate = 40psf ¾" steel pl = 30psf ½" steel pl = 20psf ¼" steel pl = 10psf (and so on) By knowing the weight of a 12" thick concrete slab, one may easily determine the weight of any thickness of concrete by proportioning. This works as well for steel. Note that a 1" steel plate actually weighs 40.8psf, but the error is small. One can use this method for finding weight of most any steel shape. For a class problem find the weight of a 6" square x ¼" thick steel tube 6" x 4 sides x 10psf = 240 lbs per foot For a 6" diameter x ¼" steel pipe the approximate weight is 6" x 3 (phi is 3.14) x 10psf = 180 lbs per foot Jun 2012

Weights of Building Construction
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Weights of Building Construction Concrete floors = 90 to 150 psf Light weight concrete is about 80% Steel systems w/ conc fill slabs = 50 to 70 psf Wood floor = 10 to 25 psf (post 1960 wood floors may have concrete fill) Add 10 to 15 psf for wood/metal interior walls each floor Add 10 psf or more each floor or furniture etc. More for storage Add 10 psf or more for Rescuers Based on past experience with design of structures Wood floor has big variation due to concrete fill. Discuss that weight of structure and interior walls are called Dead Load in design Furniture, storage and people are called Live Load in design which is different for each type of occupancy WE ARE MORE INTERESTED IN THE ACTUAL LOAD ON A SPECIFIC STRUCTURE 10psf may not be enough to allow for concentration of rescuers in wood structure - Use 20psf Jun 2012

Module 2a Shoring Basics Instructors Slides + Notes Example Assume that this 20ft x 30ft classroom has an 8" thick concrete roof with 6" of debris on it WHAT IS THE TOTAL LOAD TO SHORE ? 8" concrete = 100 psf x 20 x 30 = 60,000 lb 6" debris = 60 psf x 20 x 30 = 36,000 lb Lights, ducts, ceiling, etc. = 5 psf = 3,000 lb Rescuers = 10 psf x 20 x 30 = 6,000 lb* TOTAL (105 Kips) = 105,000 lb * 6,000 lb Rescuers allows for lb FF Is this reasonable ? If not use more, this is a MINIMUM Or give a more appropriate example for your class Examples are very useful, give reality to the numbers Jun 2012

Shoring in Multi-story Structures
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Shoring in Multi-story Structures For Existing, "Sound" Buildings - Only Wood Building: one undamaged floor can support one damaged floor Steel Building: 2 undamaged for 1 damaged Reinforced Concrete: 3 for 1 Precast Concrete: start at ground Assumptions "Normal" loading - no heavy debris, etc Not for buildings under construction See Manual & Input from StS Not for any buildings that collapse unexpectedly – w/o Quake, Blast, etc Based on assumption that most floors can support an additional 30 to 40psf if they have "normal" furniture and partition loading in place, but no occupants Wood should be able to do this in most bldgs. Steel structures weigh more and may need 2 or more floors to support one Emphasize that these are minimum requirements Does not apply to bldgs either under construction or that collapse unexpectedly – since the remaining floors may have undetected weakness or be under strength It would always be best to have a StS assess the situation Jun 2012

Shoring in Multi-story Structures – cont.
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Shoring in Multi-story Structures – cont. Sequence for multi-story Shoring – Where do you start? Start directly under lowest "Damaged" or "Overloaded" Floor in order to share the load Keep shoring in all stories vertically aligned Other Strategies Shore from Outside - In Shore for Team Access & Egress Phased approach – see next slide Spot shore - Class 1 2 Dimensional - Class 2 3 Dimensional - Class 3 Multi story sequence is logical from load sharing point of view. Start under lowest damaged level to share the load ASAP. Then add shoring to levels below, - keep shoring vertically aligned. If more than one floor is damaged, then number of required "undamaged floors" needs to be increased accordingly Strategy of phased approach Spot shores first (prefabricate as much as possible) 2 dimensional, 2nd & 3 dimensional 3rd After shoring is installed, it must be constantly checked for possible movement. Jun 2012

T Shore – 2 Post Vertical – Laced Post
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Class 1 – Class 2 – Class 3 Illustration of what is on previous slide Make sure all understand what Class 1, 2 & 3 shoring means T Shore – 2 Post Vertical – Laced Post Jun 2012

Shoring Selection Considerations
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Shoring Selection Considerations Condition of damaged floor / wall Solid with cracks Badly cracked concrete or masonry Wood joist - Wood truss Steel beam - Steel bar joist PC Concrete - T, Dbl T, I-Beam, Slab (hollow sections) Wood joist = relatively stable if shored from bottom Wood truss is not. If shore bottom of truss need to do so at panel point near where lateral bracing is attached Same considerations for Steel Beam vs Bar joist PC members like T & Dbl T should only be shored at the ends of each piece, since the reinforcing cables are normally located only at bottom of section. If apply point shoring within the span, reverse bending may cause the T to crack & break due to the unintended tension force generated in top. T and Dbl T sections also may be subject to lateral movement off narrow corbels, and need to be laterally restrained Jun 2012

FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Shoring Selection Considerations Condition of supporting surface Solid ground - slab on ground Rubble covered ground or slab Undamaged floors in multi-story bldg Basement - but now many floors below Availability of shoring materials & local contractors Need to assess what supports shoring Jun 2012

FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Shoring Selection Considerations Damaged buildings often contain vertical as well as lateral instabilities Uncollapsed building have been 10% out of plumb in one story (requires lateral shoring to support 10% of total weight of building + aftershock) StS needs to design Explain why 10% offset generates 10% lateral load with next slide – see example on next slide If one has placed lateral shoring, it must also be able to provide some aftershock (or wind) resistance in addition, since it is likely to receive aftershock forces Jun 2012

Building Out of Plumb Forces
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Building Out of Plumb Forces 100K 10K 10ft Rescue firefighters understand moment of force from Mod 4 Lifting & Rigging Should easily understand 100 x 1 = 10 x 10 1 1ft Jun 2012

FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Shoring Selection Considerations Collapses with large pieces may have unseen interdependencies Sloped floors & walls are difficult. Loads are vertical due to gravity Contact surfaces are sloped and lateral forces need to be considered and resisted. Will discuss sloped floor shores later Jun 2012

Needs for Shoring Systems
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Needs for Shoring Systems Easy to calculate Total Load of structure Don't know where load is concentrated Similar to mine collapse - unknown load distribution Shoring system must give warning of overload Need recognizable "Structural Fuses" Brittle failure mode is highly undesirable Avoid systems that have Buckling Failure The columns & walls in the structure below were designed to support all of the weight from above, but how it's transferred to the columns may not be easily determined Jun 2012

Use Unique Property of Timber To Provide Warning of Overload
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Use Unique Property of Timber To Provide Warning of Overload Growth pattern of tree Rapid growth in spring deposits relatively soft fiber Slower growth rate in summer deposits more dense fiber If load end grain, crushing strength is determined by summerwood If load is on side (cross-grain), soft springwood determines strength Cross-grain bearing failure is slow and noisy - (gives warning) Very important that student understands this concept Is basis of design for most FEMA shores Can pass around a piece of wood for example. May use a group of straws to illustrate how wood has different properties when bearing is perpendicular to grain Jun 2012

Module 2a Shoring Basics Instructors Slides + Notes Capacity Of Wood Posts Slenderness (L/D) determines the buckling strength of a wood post (L/D = length/width) Buckling failure is sudden and undesirable The maximum allowable L/D is 50 For better failure mode posts should be constructed so their L/D is less than 25 This will insure that cross-grain crushing can occur and be observed at a load that is lower than the Buckling Load. Use wood dowel, aluminum bar or something else to demonstrate Buckling Then have someone in class hold mid height of dowel or bar (with pliers, etc) to demo how a double buckle wave is formed that requires 4 times as much force to buckle Also discuss that "D" is least dimension for rectangular cross-section and L is the clear length of a post (or brace) Jun 2012

Example of wood joint with good performance
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Example of wood joint with good performance This represents a bearing stress of 2000 psi We design our shoring for 660 psi or so The crushing starts at abt 1000 psi One can hear the wood crush Notice how the wood grain pops-up beyond the bearing surface Upper Left One can see how an impression was left by a nail that had been driven into the joint. Jun 2012

Capacity of Wood Posts For L/D to be 25 or Less
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Capacity of Wood Posts For L/D to be 25 or Less 4 x 4 should be kept shorter than 8 feet 6 x 6 should be kept shorter than 12 feet This is not always possible If a post is properly braced at its mid-height, its Effective length is half its Total length. Bracing must be placed in N-S as well as E-W direction and properly nailed FEMA, US&R shoring has lots of bracing Make sure all understand concept of Effective Length And that effective bracing needs to be constructed about both X and Y axis Might want to also discuss this concept when using a member with rectangular cross section Jun 2012

Vertical Shoring Systems
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Vertical Shoring Systems Wood Posts Ellis Clamps & Jacks T - Spot Shore Window / Door Laced Posts Ply Laced Posts Cribbing Steel Pipe Metal Frames & Joist Pneumatic Shores Shores for Sloped Surfaces Quickly move to next slide Jun 2012

US&R Shoring Terminology
FEMA US&R Response System Structural Collapse Technician Training Module 2b Shoring Construction- Instructors Slides + Notes US&R Shoring Terminology Header Sole Plate Post Wall Plate Raker Raker Cleat Gussets Diag brac'g Ply Braces Collects load at roof and floor Transmits load to floor or ground 4x4 or 6x6 from header to sole Collects load from wall/vert. surface 4x4 or 6x6 from wall plate to sole 18" to 30" 2x connection pieces 5/8 or 3/4 Ply (or OSB) connections ( 12"x12" full, 6"x12" half, 12"x24" double) 2x4, 6 as X or V between shores 8" & 24" wide ply horiz. braces at PLP Make sure that everyone understands this nomenclature It can be confusing if incorrect terminology is used, especially in an emergency These are the most common terms Sect 2b slides have additional items Jun 2012

Vertical Wood Shore – Class 2
Plywood half-gussets to post, 1 side at top with x4 & 6x6 header (Dbl gusset + add on opp. side of diag brace at bottom) 2x6 diag braces 1x6 brace for 4x4 > 8' (3/4" x 6" ply is alternative) Full width wedges w/ keeper nails. Nail 2x6 diag. brace w/5-16d to sole, header, & each post (may use 3-16d to post at bottom) Note that wedges are placed with long direction parallel to sole length. Need posts cut short enough so one can fully marry wedges (otherwise will leave void) Note that after diagonal braces are installed you can't adjust wedges much. If adjustment is needed, you need to place shims under sole or above header NOTE FROM 2009: 6"x12", Half-gussets are now substituted for 12"x 12" gussets. Advantages are: easier to see wedges cup, fewer nails (8 instead of 5 & 8) faster built & less hammering in Collapse Zone Mid point brace is placed ea side post under the diag when posts are over 8' long. Use 1x6 of 3/4" ply strip Discuss with students the need to have gussets each side to prevent dislodging or roll-over of wedges. This, of course means that vertical shored are not as easy to adjust, should shrinkage or load shifting occur . If the wedges become loose, one can still hammer them tight, but if the load shifts, one may need add shims above the header, or, in extreme cases build a new shore nearby

Load Path - Vertical Load
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Load Path - Vertical Load Load Quickly review Vertical Load Path in preparation for next slide where Discuss Lateral Load Path Resistance Jun 2012

Load Path - Lateral Load
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Load Path - Lateral Load Resistance Load Everything reverses when Load comes from the Left Load Carefully Explain how Lateral Load in Header resolves itself into a Tension Force in the Diagonal and a Compression Force in the Left Post Also how the Tension Force in the Diagonal is then resolved into a Compression Force in the Sole and the Right Post. The point of this Discussion is to convince the Students that the Joints shown on the next slide should be made to most efficiently transfer these forces Explain how when Lateral Load reverses, the far side tension diagonal resists the force Resistance Jun 2012

Vertical Shore - Important Joints
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Vertical Shore - Important Joints 2x6 diagonal needs to be carefully positioned To provide a competent load path To fit 5-16d to header, post & sole May use 3-16d to post at bottom To confine wedges and reduce roll over at bottom For most long-incidents, need to add gusset on opposite side of diagonal brace to protect against sole roll-over & wedge pop-out header post Very important to understand these joints. If diagonal is not placed right it will not hold joint together and not transfer the Lateral Load efficiently. Also Half-gusset allow beter view of wedges Joint is compromise between intersection of the Member Centerlines and positioning Members so that there is space for 5-16d nails in Diagonal and Header or Sole Diagonal (may use only 3-16d to post at sole-less room) should not completely cover joint with header/sole: Edge of Diag intersects center if Post at contact with Header/Sole If vibration and/or shock loading is possible it's important to have connections on both sides of post prevents wedges from roll-over or pop-out sole Jun 2012

Vertical Wood Shores 4x4 Posts System with 4x4 Sole
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Vertical Wood Shores x4 Posts System with 4x4 Sole Header Size Use 4x4 min. if posts are placed directly under floor beams or when supporting intact/rigid concrete slab or beam. See Structures Spec for other conditions H = Height Design Load Each Post 8' - 0" 8,000# * 10' 5,000# 12' 3,500# We now only give Design Load of the posts. It is then assumed that if one uses a 4x4 header, the load on the header will be minimized. If that is not the case, the StS MUST be consulted for an assessment of adequate header for the situation 660psi cross grain bearing is based on code values for Doug Fir For other species, see SOG or FOG Frequently Asked Questions * = based on 660 psi cross-grain bearing Jun 2012

Vertical Wood Shores 6x6 Post System with 6x6 Sole
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Vertical Wood Shores x6 Post System with 6x6 Sole H = Design Load Header Size Use 6x6 min. if posts are placed directly under floor beams or when supporting intact/rigid concrete slab or beam. See Structures Spec for other conditions. Height Each Post 12' - 0" 20,000# * 14' - 0" 14,500# 16' - 0" 12,000# Same discussion as previous slide. Only difference is that 6x6 system is much stronger. Due to lack of ability of 6x lumber the 6x6 system is seldom built 18' - 0" 9,000# 20' - 0" 7,500# * = based on 660 psi cross-grain bearing Jun 2012

Assumptions - Vertical Shore
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Assumptions - Vertical Shore Configurations show Post Design Load for given heights The 4x4 and 6x6 Header Size assumes: Posts are 4 ft max o.c. Post are aligned with floor beams Or that supported concrete is rigid enough to span between posts If not the case - StS must design header Max. slope of floor/header is 5% (6" in 10') Make sure class understands as noted in 2 previous Since horizontal shear limits Header & Sole capacity, a reduction in depth (area) is generally proportional to reduction of capacity Note that the header overhang is limited to 1'-0" due to unknown effect of concentrated loading. This also keeps the connection from diag to header and post from being mis-aligned Jun 2012

Properties Of Good Wood
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Properties Of Good Wood Minimum of 8 Rings per Inch Slope of Grain = 8 to 1 or Less Maximum Tight Knot = 1 1/2 in. Maximum Loose Knot = 3/4 in. If Doug Fir or Southern Pine have this type of grain, Factor of Safety = 2 ? Good rules to use to check wood Most know what good piece of wood looks like Show an example of each Note that it is difficult to find these properties for Southern Pine wood. It is grown on fast growing trees that are harvested when the log diameter is only 8" or so. Jun 2012

Vertical Shore Short Term & Light Load For Light Frame where no displacement due to lateral loads, vibration or load shifting is likely For Light Frame construction, one may omit some gussets in short term situations In cases of very short term rescue, some will omit gusset at middle posts at top and use 2-16d toenails ea side for connection, where aftershocks are not possible. It is best to use the gussets in training for consistency. It is hard to predict when there will be no shock loading, so leaving off the gussets has to be a decision that is made in an individual case.

Vertical Shore – Fully connected system Gussets each side at sole to restrain wedges
This is example of Vert Shore- this on w/4 posts. Most engineers prefer having gussets both sides at sole in order to confine the wedges. One never knows if or when some sort of shock loading may occur – at non-quake events

2-Post Vertical Wood Shores
Plywood half-gussets ea. side each post, except at diagonal (gussets only one side for 4x4, 6x6 Header) 2x4 diagonal brace w/3-16d ea end & to posts (7'-6" max long to resist tension/compression) 2x4 mid brace 4x4 Posts at 4' max. o.c. (5'max. o.c. at 6x6) 2x wedges w/ toenails NOTE Half-gussets are also used here, and in all vertical shores It's just one side of a Laced Post, and easy to build If the diagonal is kept to 7'-6" or less long, it can resist tension or compression, and we do not need to X brace The diagonals are shown here in the form of a K brace, but either diagonal may be placed in either direction. This may be easier to teach, since it is similar to half of the three post Vertical Shore System. This shore has more possibility of being prefabricated that 3 post vertical, and can be integrated into a Laced Post Sys to provide a well braced, 3 - dimensional system. For that reason, the half-gussets are shifted to the face of posts Same as One Face of Laced Post Shore

Module 2a Shoring Basics Instructors Slides + Notes 2 Post Vertical Shore Built during training (Diagonals may be in any configuration, K or parallel) Example of 2 post Vertical Shore with diagonals parallel. Again the diagonals may be placed in either direction: K, backwards K, or parallel with top at the right, or top at the left (note that gussets should be shifted or will need to cut them, if a this is converted to a Laced Post) It is difficult to fit the 3 nails from the 2x4 diagonal into the post, so about half the width of the post should show as it contacts the header or sole, after the diagonal is placed. May use a 4x4 header with 4ft post spacing Remind class that min Header depth is 1" per ft of Span & 4x6 is min. for 5ft post spacing This example has the new, 6"x12" gussets. They fit more easily, especially when they are shifted so they are flush with outside face of post, and the wedges are more easily viewed Jun 2012

2 Post Vertical Shore - Limited Height
Plywood half-gussets ea. side each post, except at diagonal (gussets only one side for 4x4, 6x6 Header) 2x6 diagonal brace w/5-16d to sole, header & to post (7'-6" max long to resist tension & compression) 4x4 Posts at 4' max. o.c (5' max. o.c. at 6x6) Full width 2x wedges w/ keeper nails. 2 post vertical in short, confined areas Same Half-gusset one side at header if it's a 4x4 or 6x6 Half-Gusset each side at bottom to restrain wedges and prevent roll-over Very easy to build, and same rule of 7'-6" max total length on single brace applies Also same depth of header applies 6' Max. Height of Shore

2-Post Vert Shore Stacked 2 high in multi-floor collapse
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes 2-Post Vert Shore Stacked 2 high in multi-floor collapse Good example of how to adapt to actual conditions There are 2 levels of 2-Post Verts, and they do not quite align, but that may be OK, since the floor joist can probably transfer the load if it is reasonable light Jun 2012

880 Freeway using 12x12 & Steel W as sole, no connections or bracing
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes 880 Freeway using 12x12 & Steel W as sole, no connections or bracing Vertical Shores Good 12 x 12 posts, Poor connections & bracing The W - steel section is used in CA, but is not too good for stability Jun 2012

Module 2a Shoring Basics Instructors Slides + Notes Vertical Shores Freeway Using 12x shores & sole, no connections & bracing Sim to as previous They used multi member wood sole here + short cross soles Jun 2012

Ellis Shores - 4x4 adjustable
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Ellis Shores - 4x4 adjustable Need 2 Ellis Clamps to make a pair of 4x4 into Adjustable 4x4 shore Need Ellis Jack Failure Mode is by clamp crushing the side grain of the post - Gives Warning Design Load = 6000 lb Not in current cache 6" 12" 6" 12-0 max 7-0 max Allow for adjustable post Are not in US&R Cache Good failure Mode, Keep less than 12 ft long Jun 2012

Screw Jack by Ellis Adjustable metal foot for 4x4 and 6x6 wood posts
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Screw Jack by Ellis Adjustable metal foot for 4x4 and 6x6 wood posts 6 inch adjustment - set half way to get 3 in. up & down Metal Foot is stronger than wood post Use sole to spread load Good to provide adjustable post for initial, spot shore See next slide for use as Post - Prestresser used in Grain Elevator Tunnel after explosion Jun 2012

Module 2a Shoring Basics Instructors Slides + Notes Ellis Foot was used in Half Mile Tunnel Under Kansas Grain Elevator that Exploded Spontaneous explosion occurred in Tunnel below storage cylinders due to improper ventilation.Several workers were killed in the tunnel when the explosion occurred. FEMA, NE-TF-1 was sent to aid local rescue efforts The metal closure doors that are used to regulate the flow of grain out of the bottoms of the concrete cylindrical storage areas (into a conveyor belt) were blown off, and grain filled the tunnel below. Several workers were trapped and probably killed instantly Closure doors were blown off the bottoms of cylinders & grain filled the tunnel Jun 2012

Ellis foot used to develop friction conn. To support new closures
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Ellis foot used to develop friction conn. To support new closures Plywood closures stopped the grain flow so tunnel could be emptied using a large vacuum Unique and creative application Used after Kansas Grain Elevator Explosion to provide compression in horizontal beams so reliable friction connection could be made to tunnel side walls to support ply panels used to close off flow of grain into tunnel below grain storage areas. (so access could be provided to victims who were in tunnel) Rubber was placed between feet and wall to enhance friction Did not want to make any sparks that would ignite the grain dust Jun 2012

T - Spot Shore – Class 1 Temporary Shore Post strength is
Full Gusset Temporary Shore Basically Unstable Typical header is 3 ft and centered on Load Dbl T is more stable 11 ft Max Height (10'-3" Post) Post strength is Limited by stability 2 ft to 3 ft sole plate, same size as header Design Load = 1k? Basically unstable Keep the header at 36" max & overall height max =11ft Better to use 2 shores than one that is too wide Design Load is hard to predict, since Load must be centered on Post 2006 change use half-gusset instead of 2x4x18" cleat: less use of 16d nails in Collapse Zone & less splitting Also use Pneumatic shores as spot shores Double T is much more stable, shown next Half Gusset

Module 2a Shoring Basics Instructors Slides + Notes T shores & Ellis Foot Some examples from Rescue Classes Ellis clamps are not on current Cache List, but some TF may still have them. They make an OK adjustable spot shore Jun 2012

12"x 24"Plywood dbl gusset ea side
The Dbl "T" Shore – Class 2 More Stable than T Shore, but weighs about 25 lb more 3 ft header & sole Posts from 18" to 24" out-to-out Design Load, based on 2-Posts (length) A little harder to move into place 12"x 24"Plywood dbl gusset ea side Ply dbl gusset 1-side, mid-height This double T was added in 2004, and is a big improvement over the T It used similar parts, and is a little heavier Limit height to 12 ft SOG says post is 11'-3" = same 2006 change use half-gusset instead of 2x4x18" cleat: less use of 16d nails in Collapse Zone Half Gusset Half Gusset

Module 2a Shoring Basics Instructors Slides + Notes Dbl "T" Shore – easy to install Shore Top Chord of Truss Shore Wood Apartment Left - is great example of Dbl-T plus proper way to shore a truss – directly under the top chord Right – Is Dbl T used in wood apartment. Very quick to build and almost as effective as 2-Post Vert Shore Jun 2012

No Mid Height Ply Gusset
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes The Dbl "T" Configuration Depends on Height Max Height is 12 ft (11'-3"Post) These are the configurations for any single Dbl T In Nov05 & May06, pairs of Dbl T, spaced 4ft apart were tested . The 12" & 24" wide horiz plywood was used to connect the Dbl Ts together. The Tees were about 13ft high and failed in buckling at a load of 86kwhen using 24"ply and 65K when using 12"ply. (24" ply is recommended) For now, it is reasonable to say that the Design Load for one Dbl T should be based on capacity of 2 – 4x4 Posts 8ft high = 2 x 8k 10ft high = 2 x 5k 12ft high = 2 x 3.5k See later slides for New Plywood Laced Posts Up to 12 ft High One Mid Ht Gusset Less than 6 ft High No Mid Height Ply Gusset Jun 2012

Window / Door Shore Too complicated ? For opening in URM & Wood walls
Capacity of short posts based on Bearing Strength Header should be 1" deep for each 1' of opening width X bracing may be removed for access Ply half-gusset Be careful of limited bearing Diagonal cleat at upper wedges Req'd mostly in URM opngs, especially those with wood headers X Bracing may be removed for access Quite complicated if all wedges and connections are installed Is constructed in place See next for pre-constructed, simplified method Note Header size given is typical Rule of Thumb for MINIMUM 2012 Note: Half-gusset has replaced the Triangle Gusset. Discontinue use of Triangle Gusset - Simplify Cleats to confine wedges + post to sill connection

Alternate - Window / Door Shore
Pre-construct as box-frame, 1 ½" min. less than opening Add wedges on bottom and one side at top and bottom Add diagonal braces if wall is racked, and access isn't required Plywood half-gussets each side each corner This type could be pre-constructed, and even reused in same sized openings Tighten up shore with wedges at bottom – depending on space use 4x4 or 2x4 wedges, 1x shims or combo of both Add wedges at end of header & sole to secure in place – again fill the space as reqd 2012 Note: Half-gusset has replaced the Triangle Gusset. Discontinue use of Triangle Gusset - Simplify

Pre-fabricated Construct In-place
FEMA US&R Response System Structural Collapse Technician Training Module 2b Shoring Construction- Instructors Slides + Notes Window Shores Class example showing built-in-place and pre-fabricated window shores Discuss situations where the prefabricated shore would not work too well Pre-fabricated Construct In-place Jun 2012

Laced Posts - Class 3 4x4 Posts=4ft max o.c. Maximum Post Height:
Increase post capacity due to short effective length Maximum Post Height: 17ft with 4x4 posts, 20ft with 6x6 2x4 lacing, 3-16d each end 3 bracing bays, 11ft to 17ft high 4 bracing bays, 17ft to 20ft high Requires 6x6 Posts w/ 5ft spacing Use K layout or any other 2x6 lacing, 5-16d at 6x6 Posts Header & Sole w/ 1ft overhang Connections like Vertical Shore Design Load (660psi bearing) 4 - 4x4 x 17"- 0"max. = 32,000# 4 - 6x6 x 20'- 0" max. = 80,000# Best example of how bracing can be used to decrease effective length and increase capacity of wood post. Post spacing is based on L/D of 2x diag braces (keep 7'-6" max) Make sure that everyone understands that 3 bays of bracing are needed if shore is over 11 feet tall (4 horizontals + 3 diagonals each side). The K configuration of bracing is shown on all 4 sides for simplicity. We used to have one reverse K to improve Torsion Resistance, however the load in the diagonals is probably limited by the nail strength. Also if you reverse one K you end up with 6 members intersecting a post at one location (splits) See notes under 2 post vertical for header & gussets Can be used as Safe Haven

Laced Posts - Connections
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Laced Posts - Connections Need to carefully place diagonal at post to beam and post to sole Nail 3-16d to beam & post at top Nail 3-16d to sole & post at bottom + confine wedges Use gusset, one side at other post to beam & each side to sole (+ opposite side diagonal) 5-8d to post 8-8d to beam & sole Again very important that class understands importance of these joints. Use half-gussets as noted previously Same concepts as for Vertical Shore Note that may use a 2x2x18" cleat instead of a gusset at post bottom, you can more easily observe the wedge cupping. But 16d nails may cause splitting See following slides for Plywood Laced Posts PLP See DisasterEngineer.org for video of Tests of LP & PLP Jun 2012

Laced Post Examples Over 11 ft Up to 11 ft
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Laced Post Examples Over 11 ft Up to 11 ft Example of 2 bay and 3 bay types 3 bay has missing horiz tie at bottom Jun 2012

Laced Posts Test Prefab Change to Half-Gussets
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Laced Posts Test Prefab Prefab 2 sides away from collapse. Move them inside as with T shore, to add sole & wedges. Then lace the 2 "Spot Shores together to provide braced system Right example is from Laced Post Tests during StS Training. There have been over 40 teats. Failure occurred between 90 and 140k (Design is 32k) See DisasterEngineer.org for video of Tests of LP & PLP See DisasterEngineer.org , Links , for Fire Engineering Article on these tests Change to Half-Gussets Jun 2012

Laced Post – Class 3 Limited Height Area
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Laced Post – Class 3 Limited Height Area For less than 6 ft high spaces 4x4 Posts=4ft max o.c. 6x6 Posts = 5 ft max. o.c. Built as a half high Standard Laced Post As for all "Vertical" shores, headers may slope up to 6" in 10 ft Just showing another variation of laced post What to do in short space Jun 2012

Plywood Laced Posts - Class 3
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Plywood Laced Posts - Class 3 With 4ft x 4ft out to out Post Spacing Use 4x4 or 6x6 posts Min ht=4ft; Max ht = 17ft Use 5/8 or 3/4 ply braces Mid-plywood braces are 24"x 48" 11-8d nails each end One level of braces, 4' to 9' high 2 levels of braces 9' to 13'high 3 levels of braces 13' to 17' high Top & bott. braces are 8"x 48" 6' long header & sole Connections like Vertical Shore 2x4 wedges on sole (2x6 at 6x6) Design Load (660psi bearing) 4 - 4x4x17"- 0"max. = 32,000# 4 - 6x6x17'- 0"max. = 80,000# This is the new Plywood Laced Post. This one is built in a 4ft x 4ft configuration up to 17ft high The plywood may be 5/8" or 3/4" These are lighter and faster to build than standard laced posts, but the design strength is same. See DisasterEngineer.org for video of Tests of LP & PLP See DisasterEngineer.org , Links , for Fire Engineering Article on these tests Jun 2012

Plywood Laced Posts - Class 3
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Plywood Laced Posts - Class 3 With 2ft x 4ft out to out Post Spacing Use 4x4 or 6x6 posts. Min ht.=4ft; Max ht.=13ft Use 5/8 or 3/4 ply braces Mid-plyw'd braces are 24"x 48"and 24"x 24", with 11-8d nails each end. One level of braces, 4' to 9' high Two levels of braces 9' to 13'high. Top & bott. braces (4'side) are 8"x48" 4ft long header & sole Double gusset one side at header Half gusset ea. side at sole & wedges Design Load (660psi bearing) 4 - 4x4x13'- 0"max. = 32,000# 4 - 6x6x13'- 0"max. = 80,000# This is the new Plywood Laced Post. This one is built in a 2ft x 4ft configuration up to 13ft high The plywood may be 5/8" or 3/4" These are lighter and faster to build than standard laced posts, but the design strength is same. See DisasterEngineer.org for video of Tests of LP & PLP See DisasterEngineer.org , Links , for Fire Engineering Article on these tests Jun 2012

Module 2a Shoring Basics Instructors Slides + Notes Wood Cribbing – Class 1? Capacity based on cross-grain bearing area of system Allow stress varies from 200 to 1000psi for wood species For 2 member x 2 member crib 4x4 Design Load = 24,000# (500psi) x6 Design Load = 60,000# Limit Height to Width to 3 to 1* See recommended height limit below Stability and Deflection Issues Crib can crush as much as 20% *Recommended to Limit Ht to 4 ft for 4x lumber & 6 ft for 6x Overlap corners 4" minimum The most Ductile wood system as long as it's kept stable Important to overlap corners & limit Ht/Width Used for centuries in Mines Use 500psi (for Doug. Fir & S. Pine) since there will be significant shortening of crib when crushing of wood occurs Make sure that all understand that there will be crushing at each side of each wood piece at each bearing, which can add up to 7" in a 3 ft crib if the total shortening is 20% of original height Discuss that the recommended height limits of about 4 ft for 4x lumber and 6ft for 6x is based on stability concerns. As the wood starts to crush it is possible for some members to crush more (due to knots, different grain etc) than others and the crib may tilt & become unstable. If one uses a 3 member x 3 member configuration some of the instability can be overcome, and the deflection will be less than half as much Jun 2012

Cribbing Layout 2 X 2 3 X 3 Solid Bearing Both these not
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Cribbing Layout 2 X 2 3 X 3 Solid Bearing W W W is min Width of configuration 1 to 1 is recommended for any odd configuration Both these not very stable. Keep Ht to W 1 to 1 max Triangle Parallelogram Jun 2012

4x4 Cribbing w/ 4 Bearings 6000# each contact Load on all corners
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes 4x4 Cribbing w/ 4 Bearings 6000# each contact Load on all corners Most Stable - Ht to W = 3 to 1 max Poor choice since loading is non-uniform Keep Ht to W within 1 1/2 to 1 6000# each contact Important to load cribs as uniformly as possible Location of victims sometimes requires some of these other layouts Jun 2012

6x6 Cribbing at Front of Collapse Zone
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Pentagon 6x6 Cribbing at Front of Collapse Zone Current Recommendation is to limit height of 6x cribbing to 6 ft due to stability concerns 5 Story concrete bldg at Pentagon 1st story was about 15ft high and many concrete columns were badly damaged and shaped like a banana 6x6 cribbing was installed at the front edge and because of the fear of collapse. Additional cribbing was place inside the structure as crews worked their way in There was also concern that the debris from the sloped collapse area would slide into the adjacent cribbing. Perhaps the use of Laced Posts should have been considered - 6x6 Laced Posts with 80,000lb capacity Under the new recommendations, 6ft would be the height limit or 6x cribbing, however these cribs were 3x3 member and 4x4 member. They would be less vulnerable to unstable behavior Jun 2012

Module 2a Shoring Basics Instructors Slides + Notes 4x4 Wood Box Crib Test Load = 17k Slab + 25k Blocks Total Load = 42k = 870psi Deflection. = 6" (24k Design) Before After This is photo of 6ft High Cribbing Test Test demonstrated how much Cribbing will crush, even at relatively low stress (6 inches in 6ft) For Laced Posts the crushing was only about 1.5" when the stress in each 4x4 was 2000psi. FEMA Structures Sub-group now Recommends that use of Cribbing should be limited to 4ft high for 4x & 6 ft for 6x. Also only used when significant vertical deflection will not cause a problem Jun 2012

Pipe Shores – Class 1 Not in US&R Equipment Cache
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Pipe Shores – Class 1 Not in US&R Equipment Cache Rent from Concrete Service Co. Design Load based on diameter & length of shore 2"dia. pipe x 10-0 = 6,000# /2" dia. x = 6,000# Design Capacity of system using wood header and sole may depend on base plate area These have been used in US&R Are often used where height is so great that buckling failure will be most probable, not crushing of sole or header The values listed here are about 90% of the calculated allowable working load based on A-36 steel (author's recommendation) Check Kee Klamp on the internet, They have a site that shows pipe shores Jun 2012

Pipe Shores - OKC - high L/D
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Pipe Shores - OKC - high L/D Not too bad in this application, since load was relatively easy to calculate Jun 2012

Aluminum Frames – Class 3
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Aluminum Frames – Class 3 Available in 20k per 2 leg frame up to 50k Design Capacity of frame may depend on foot bearing plate Aluma Beams have wood nailer and can span up to 20' Have been used as shield/shelter Very high capacity frames Use wood sole plates to spread load & give indication of load (crushing should indicate loads over 1000psi on foot area) Jun 2012

1971 L.A. Quake Small roof load, 18ft high
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Alum Frames at OKC Just a couple of examples Frames used after 1971 L.A. Quake Small roof load, 18ft high Jun 2012

Module 2a Shoring Basics Instructors Slides + Notes Aluma Beams 7 1/2" 191 mm 6 1/2" 165 mm 5 1/2" 140 mm Aluma Stringer Beam Beam Available from Concrete Supply (Burke) Up to 20 ft spans - use Plywd Sheathing Good Dynamic Properties to stop falling objects more slowly - absorb energy Great system to use for protective shield structure to protect Rescuers from falling hazards Alum. has 3 times flexibility as steel and similar strength Plywood may be nailed to Aluma Beams 3s Jun 2012

Two levels of Aluma Beams + plywood w/Rescue working under
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Puerto Rico - Aluma Beam Platforms used to shields from falling hazards In this case the explosion did not collapse the concrete & steel beams - just blew off bar joist/light slab floor Rescue had to work in basement below Double layer where falling hazards were greater Lots of redundancy and flexibility Two levels of Aluma Beams + plywood w/Rescue working under Jun 2012

Pneumatic Shores – Class 1
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Pneumatic Shores – Class 1 Adjustable Shore up to 16 ft long Manufactured by Hurst-Airshore and Paratech Have Swivel & other feet Hand tighten (snug) using adjustable collar or sleeve nut May use up to 50psi air pressure to raise into position Design Strength decreases with length and should be based on tests using swivel ends Best use is as Initial, Spot Shore Great, adjustable, initial, spot shores Note that accidents can happen when raising these shores using air pressure. Use care and limit pressure to 50psi See Struct Spec FOG and following slides for Recommended Design Loads DO NOT use the CAPACITY values published by Airshore, they do not have an adequate Safety Factor. As example for 14 ft the S.F. is about 1.5 and at 12ft it is about 0.9, based on the tests performed at CATF-3 Test Site Also the Airshore Pin and collar will permanently deform if the struts are loaded to the 30,000 lbs Jun 2012

What About using Extensions for Pneumatic Shores?
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes What About using Extensions for Pneumatic Shores? Don't use extensions unless you have to Shipping Pallet size is 104" x 84" this is a problem for 10' to 16' Strut Extensions available in lengths from 1' to 6' Joint between Strut & Extension must be tested to demonstrate adequate strength Paratech & Hurst-Airshore have successfully tested their joints and recommendations for struts used with one extension are included in the SS FOG and the following slides The strength of these struts increases significantly as the inner tube is retracted. When adding an extension, the Strut should not be in it's longest position with min overlap, it is much better to retract it a little in order to support the extension Jun 2012

3 ½" 3 ½" 3 ½" 3" Strut Extensions Paratech Extension OK
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Strut Extensions Paratech Extension OK Airshore Problem 3 ½" Good One 3 ½" Paratech Extensions are connected to strong end of shore (3 ½" end) The joint has been tested in an assembly acting as a beam, with the joint at the center. It transferred the calculated Moment at specified min yield strength It is an acceptable joint It does not reduce the strength of the strut, and one may use the recommended safe working values in the US&R chart, based on the total length of the assembly Airshore originally extended from the small end, so had to redesign – some of their old joints may still be used Do Not Use this one 3 ½" 3" Jun 2012

Recommended Design Strength for Hurst-Airshore Struts used in US&R
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Recommended Design Strength for Hurst-Airshore Struts used in US&R Similar results as Paratech Not quite as strong The pin tends to start deforming the Aluminum Collar at abt 30k (note that MFR's literature recommends Safe Working Load of 30K) S.F. is abt 3 Jun 2012

Spot Shores – 14ft high Design Strength = 12K
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Hurst-Airshore Struts These are example of "Airshores" Other manufacturer is Paratech 3- Column – at Pentagon Spot Shores – 14ft high Design Strength = 12K (Design Strength, 1 - 6x6 = 14.5K) Jun 2012

Recommended Design Strength For Paratech Long Shore Struts in US&R
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Recommended Design Strength For Paratech Long Shore Struts in US&R Paratech Long Shore Struts are 3½" in diameter (Gold Anodized), which is larger than original 3 " dia. Paratech Rescue Struts. Paratech Rescue Struts (3" dia., Dark Grey) should be used ONLY up to 8 feet long They have a strength similar to the 3½" struts for lengths up to 6 feet Strength drops to about 14,000 lb for 8 ft See Manufacturer’s recommendations following. Make sure all understand that the 3" diameter Paratech Struts are much weaker at lengths over 6 feet Paratech says they will color code their Struts Original 3" dia = Bronze anodized New 3 1/2" dia Long Strut = Gold anodized The original 3" dia struts still can provide strong and useful, temporary shoring, especially in confined spaces and trenches. They have safe working strength of 22,000lbs (same as Long Struts) if they are used at 6ft long and shorter Jun 2012

Recommended Design Strength For Paratech Long Shore Struts in US&R
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Recommended Design Strength For Paratech Long Shore Struts in US&R Recommended Design Strength, base on Tests done at CA-TF-3 Safety Factor is about 3 Jun 2012

Module 2a Shoring Basics Instructors Slides + Notes PARATECH Rescue Struts – Load Table Based on Tests by Paratech, Reviewed by Wiss, Janney, Elstner, Engineers Available from 1.5 to 7ft Extensions avail. In 12", 24" and 36" lengths (use max. of one extension per strut) These values are based on limited tests by Paratech Recommend using 4 to 1 S.F. Jun 2012

Paratech Rescue Strut used in Turkey
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Paratech Rescue Strut used in Turkey Just examples of strut use Jun 2012

Shores for Sloped Floors – Class 3
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Shores for Sloped Floors – Class 3 In Normal Construction, one cuts Level Bearings in Wood Rafters (Birds Mouth) WE CAN'T DO THIS UNSAFE AND NOT PRACTICAL Emphasize that this is NOT good method for collapsed structures Just an example of how it can be done in typical wood construction - cut birds mouth Unsafe to cut damaged floor Since bearings are level, loads are transferred vertically without generating any sloped forces Not the case for Sloped Floor Shores Jun 2012

Shores for Sloped Floors
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Shores for Sloped Floors Sloped Floor is defined as over 5% 6 inches in 10 feet Build them in pairs with bracing between Similar to Laced Posts = Class 3 There are basically 3 designs: Perpendicular to Slope Method Type 2 (Type 1 is no longer recommended) Friction Method – Type 3 Cribbing – Type 4 30% (3 ft in 10 ft) max. slope This gives the limits of what is considered as a "Normal Vert Shore) and what is a "Sloped Shore" Normal Vertical Shores may be used for slopes up to 5 percent - which assumes a friction force of 5 percent. Note that Type 1 Sloped Fl shore has been eliminated, since it requires dug-in bases, and the other types will work on soil, plus are less dangerous to build The use of Cribbing needs to be limited to a 30% slope, that is 3 feet in 10 feet (not 30 degrees) Discuss that there really is no maximum angle for a Type 2 or 3 sloped floor shore. The writer would suggest that above 45 degrees or so, one should consider building a shore more like a solid sole raker shore in pairs. See discussion in notes for Slides 96 & 97 Jun 2012

Shores For Sloped Floors Perpendicular to Slope Method
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Shores For Sloped Floors Perpendicular to Slope Method Concrete Floor Slab (may be connected to remaining structure) Bearing load direction is perpendicular to contact surface between shore and structure Gravity Load Sloped force resisted here or by remaining structure Slope force depends on degree of slope Force in shore is perpendicular to contact surface Make sure all class members understand concept. (depends on assumption that all of the sloped force is resisted by rubble or remaining structure). If sloped floor is not connected or well embedded in rubble, then friction must resist it. Then force in shore will be resultant of friction + perpendicular forces - which is not perpendicular to sloped slab. This will be discussed after slide on cribbing used for sloped floor support Note that normal Vertical Shores should be used for slopes up to 5 percent To shore sloped surfaces we must provide a system that will resist both vertical & lateral forces Jun 2012

Type 2 – Sloped Floor Shores
Bearing force is perpendicular to shore & slope force parallel to slab Gravity Load Use half-gussets ea side posts top & bott. except at diagonals Header 4x4, 6x6 Shores cut to bear 2 ways at bottom 2x Bracing Nailed cleats Slope force needs to be resisted by rubble & ground Better system than original Type 1, and with addition of 18" wood feet under posts, will work in soil May be able to pre-fab and not need spot shores Could be built away from damaged area & slid into place, then fill-in, shims above header Use wedges against sole anchor to adjust (omit wedges from sole cleat to post – see next slide) Construct in pairs and brace between with lacing as in Laced Posts, or use plywood at short end Wedges should not be used at post to sole, since they get in the way of bracing. Post may be made tight by moving then into the slope Add 18"x18" foot under sole, ea post when used on Soil Sole must be kept from sliding Gravity load resisted Add 3-2x6x18" under each post on soil Type On Concrete, Paving or Soil (Perpendicular to Slope Method)

Module 2a Shoring Basics Instructors Slides + Notes Type 2 - Sloped Floor Shore Half-Gusset at bottom left off to show cuts at joint Type 3 Half-gussets have been added electronically. Lower one shown removed in order to see the cuts on the post. Note that the wedges between post and sole cleats are not used here. Post can be driven tight w/o wedges, then cleat can be nailed on tight. Wedges tent to conflict w/ diagonals The brace between shores at short end is only one 2x6. It should be a strip of ¾" plywood 12" min wide Jun 2012

Type 3 – Sloped Floor Shores
What to do if Sloped floor is NOT connected to Remaining Structure or Embedded in Rubble System with shaped top - vertical shores, cut to mate with cleats & header will transfer both the sloped & perpendicular forces Gravity Load Concrete Slab Drill-ins Gravity Load Gravity load in floor is resisted by sloped friction Force + Force perpendicular to Sloped surface This is suggestion of what might be done if sloped floor is not connected to remaining structure or embedded in rubble. Note Half-Gussets If can mobilize friction (how reliable?) in order to make resultant forces that act vertically If any way to attach to bottom of slab, such as waffle slab voids or other protrusions, this would be more reliable. Note: drill-in anchors thru header, set in epoxy or other adhesive (liquid nails) - or rebar in tight hole. Wedges are optional, but are consistent with vertical shores. Add 18"x18" foot under sole, ea post when used on Soil No Reliable Resistance Anchor Vert. load resisted by ground Add 3-2x6x18" under each post on soil Type 3 - Friction Method (On Concrete, Paving or Soil) (For slopes over 5% need Connection between Header & Slab)

Module 2a Shoring Basics Instructors Slides + Notes Type 3 - Sloped Floor Shore Half-Gusset at top left off to show cuts at joint Type 3 Shows layout and post cuts. Typical return cut as for rakers Jun 2012

Type 3 - Sloped Floor Shore Shown without optional wedges
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Type 3 - Sloped Floor Shore Shown without optional wedges Type 3 Example from Training Jun 2012

Type 3 - Sloped Floor Shore Friction Method
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Type 3 - Sloped Floor Shore Friction Method Type 3 Example with wedges Use half-gusset Jun 2012

Some Practical Solutions
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Some Practical Solutions More like a Flying Raker Discuss that sometimes it may be better and faster to adapt shoring to the condition – especially w/wood construction Left - is 3-Post vert Shore, angled to meet the load, and resisted at base w/raker like sole. Note that diag bracing also included Right – is simpler, but less stable solution. Is good as long as original structure provides the lateral bracing As previously mentioned for slopes above about 45 degrees, one should consider other alternatives like these, or a series of well braced solid sole rakes. Vertical Shore on angle w/raker-like sole & cleats Jun 2012

Lateral Bracing For Paired Sloped Floor Shores
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Lateral Bracing For Paired Sloped Floor Shores For pairs of shores, spaced up to 5 ft o.c. use bracing between shores as in Laced Posts. or For pairs of shores, spaced up to 5 ft o.c. use solid plywood strip when height is 3 ft and less. For 2 or more shores, spaced up to 8 ft o.c. , use longitudinal and X and/or V bracing as in Raker Shores. Bracing between pairs should have a min. of horiz. top & bottom + one diagonal or ply strips as in Laced Posts. Bracing may done as in Raker Shores, with 2x6 longitudinal top & bottom + tension diagonals Rakers will be discussed next in Lateral Shores The bracing will be discussed in Shoring Construction Module Jun 2012

Slope Floor Lacing Shores up to 5 ft o.c. 2x6 or 2-2x4
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Slope Floor Lacing 2x6 or 2-2x4 Two shores must be erected. Spacing as necessary, 4 to 5ft maximum. Brace with lacing as shown in front and back. For spacing over 5 ft use bracing as for Raker Shores, horizontals + X bracing (see 2nd next slide) Use 2x6 bracing.(2-2x4 OK) If shore is less than 3 feet high, 3/4" plywood can be used instead, see next slide. Shores up to 5 ft o.c. Jun 2012

Slope Floor Brace When too short for lacing
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Slope Floor Brace When too short for lacing 12" max 12" to 24"- 5/8 or 3/4" plywood strip 2 rows 3" o.c. to posts For spacing up to 5 ft and height less than 4 ft, a 3/4" x (12" to 24") strip of plywood may be used for bracing two sloped floor shores together. Maximum distance from edge of plywood to top or bottom of shore should be about 12". 12" max Shores up to 5 ft o.c. Jun 2012

Slope Floor X Bracing Shores 8 ft max. o.c. 2x6 or 2-2x4
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Slope Floor X Bracing 2x6 or 2-2x4 Two shores must be erected. Spacing as necessary, 5to 8ft maximum. For spacing over 5 ft use bracing as for Raker Shores, horizontals + X bracing (see 2nd next slide) Use 2x6 or 2-2x4 for bracing Shores 8 ft max. o.c. Jun 2012

Shores For Sloped Floors Cribbing - Type 4
Bearing Force Gravity Load Slope forces are often resisted by friction Center of load should be contained within mid half crib Sloped Floor Build cribbing into load by adding 1x nailed to crib 4x 4x, 6x set in from corners Force in crib will be mostly vertical, but have horiz forces due to slope & aftershock Option- add 3/8"min plyw'd strips with each edge for lateral strength House movers have been using cribs to shore sloped floors for years Limited to shallow slopes, and heights to about 4 ft Need to keep center of load within mid half, as shown Important to keep load on crib as uniform as possible Another way to make the angle id to use half of 4x4 wedge sets, placed on top of and parallel to a layer of cribbing members. May be done at more than one layer Need to find simple, effective way to tie crib members together - transfer shear without needing to count only on friction Adding plywood or diagonal bracing to sides of 2 by 2 crib is not useful, if Crib crushes much - incompatible Bottom layer needs to be solid to spread load

Crib at sloped slab in OKC
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Crib at sloped slab in OKC Type 4 Common example for victim access Jun 2012

Summary for Sloped Floor Shores - 1
No simple, "one fits all conditions answer" Need to resist load in direction it's tending to move Wood floors need header perpendicular to joist. Use Vertical Shores for slopes up to 5% (6" in 10 ft) Type 2, Perpendicular Bearing Method may work most of the time for concrete floors, since they often remain connected to structure. Type 3, Sloped Friction Method needs a connection between header & floor. Use cribbing up to 4 ft high & up to 30% slope (30% slope is 3 ft in 10 ft, and about 15 degrees) Emphasize that one really needs to see actual condition in order to design proper system. Struct Spec and Rescue need to work together, more than ever in this case Due to unknowns and sloped forces, need very competent bracing in east-west as well as north -south direction. (consider 2x6 for bigger nailing area) Add your own ideas - and contribute them to the US&R System As previously mentioned for slopes above about 45 degrees, one should consider other alternatives like those on Slide 73, or a series of well braced solid sole rakes. It all depends on the situation, and there is no RIGHT Answer for all cases

Summary for Sloped Floor Shores -2
Design Load for pair of braced, Sloped Floor Shores using 4x4 posts: May be assumed to be 24k for angles up to 15 degrees (3 ft in 10 ft) – 60k when using 4-6x6 Posts The angles and adequacy of the bracing can reduce the strength, especially for steeper angles The capacity of the sole anchor is critical The StS should always determine the Design Load At angles above 45 degrees, consider other alternatives Make sure that all understand that there are too many variables to have a simple number be given as the capacity of and system of sloped floor shores. The number given below is for ideal conditions and at a limited angle The TF Struct Spec should always we involved in the design of these systems. What will work well in a concrete building will probably not work in a wood building. The Design Load of 24,000lb (24kips) may be used for a pair of Sloped Floor Shores (4x4 posts) and 60,000 (60k) for 4-6x6 posts, for slopes up to 15 degrees . For slopes above 15 deg the design load would be decreased. The bracing and sole anchorage of sloped shores will be very critical and may severely limit the strength. The StS needs to evaluate every case

Lateral Shoring Systems
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Lateral Shoring Systems Horizontal Shores Trench Shores Raker Shores Tiebacks Jun 2012

Wood Horizontal Shore Cleats one side at wedges Used to brace bulging
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Wood Horizontal Shore Cleats one side at wedges Used to brace bulging walls, usually URM If posts are short, capacity is based on cross grain bearing X bracing is removed for access & use half gusset connections 2012 omitted the Triangle Gussets, and now use Half-Gussets Very common type of shoring for Firefighters Walls bulge due to Fire damage 4x4 struts usually less than 8 ft long Similar in complication to Window/Door shore if all pieces are connected together Discuss adding corner half-gussets if diagonals are removed for access Cleats are used on top of ends that have wedges. Helps confine wedges Half Gusset Spaced 8' o.c. maximum. Jun 2012

Hydraulic Trench Shores
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Hydraulic Trench Shores Aluminum hydraulic rams w/side rails Pressurized w/5 gal hand pump to psi Installed w/special plywood sheathing Spacing depends on Soil Type, Depth & Width Must maintain pressure to carry load - no lock O.K. for trench shores Not good for US&R structures since no way to positively lock - only rely on hydraulic pressure (check)valve. Jun 2012

Other Trench Shores Trench Jack - same capacity as vertical
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Other Trench Shores Trench Jack - same capacity as vertical Post Screw Jack - same as vertical Pneumatic Shores - same as vertical (intended as trench shores and are first extended w/ air pressure and then set with nut or pin for positive connection) USE MFR'S PIN END VALUES All can be used as trench shores Jun 2012

One Side Trench Shore Need Design by StS Bracing Frames at 4’ o.c.
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes One Side Trench Shore Need Design by StS Bracing Frames at 4’ o.c. Better to use 30deg Slope 4x4 or 6x6 members Depends on Height & Soil Class C Soil (80h+ 72)psf Need 3x or 4x sheathing Need very good Anchor Sys Need perpendicular 2x6 horizontal & X- bracing Sys Emphasize that there is no "Standard Solution" for this type of Shore. Best to have input from Geotechnical Eng and Design by StS It may be needed for the following: To add height to a river levy (water pressure) To brace a basement excavation cave-in (Class C Soil) Mud-Slide or Rock Slide (near concrete pressure 130pcf) Obviously the anchorage is very important Jun 2012

Diagonal - Raker Shores
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Diagonal - Raker Shores Vertical force tends to move shore up the wall. To resist this shore needs to bear on ledge or be connected to wall w/ anchors, etc. Apply horizontal force to stabilize structure Insertion Point Horizontal reaction is resisted by sole anchor, pickets into paving or ground, push on curb, etc. Raker Shore = Diagonal 4x, 6x timber or other. Need to keep effective length reasonably short by using lateral bracing Carefully explain Show example using dowel or 1" x 1" wood piece with shaped ends. Vertical reaction is resisted by paving or ground using foot. Jun 2012

Module 2a Shoring Basics Instructors Slides + Notes Poorly organized raker Brownsville, TX best quick shore here is Front End Loader Only good temporary shoring here is Front Loader. The wood is so poorly organized that it was not worth the risk to build it. If we don't build it right, it's probably better to reduce risk by reducing exposure. Jun 2012

Rakers, S.Cruz, 89 EQ Not effective, too steep & no conn to wall
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Rakers, S.Cruz, 89 EQ Not effective, too steep & no conn to wall Much time spent on this installation Not very effective Showed great need for training. Jun 2012

Module 2a Shoring Basics Instructors Slides + Notes Raker in SF 89 Loma Prieta Quake By Struct. Eng., protect Day Care Center This semi-permanent shoring was designed by Structural Engineer & constructed by Contractor. Illustrates good practice. Typical corner Knock-Out damage of URM Jun 2012

Raker by S.E. in 89 Loma Prieta Quake
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Raker by S.E. in 89 Loma Prieta Quake Cleats w/drill-ins to URM Concrete Footing Very good top cleat - thrust blocks Wedge anchor drill-ins. FEMA Raker Systems are Next Jun 2012

Flying (Friction) Raker (Spot Shore)
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Flying (Friction) Raker (Spot Shore) 5/8"or 3/4" backing at wood walls and badly cracked conc./urm walls 4x4 wall plate & rakers w/2x6 bott. brace or 4x6 wall plate, 6x6 raker & 2x6 bott. Brace Ply gussets each side, raker to plate Need to connect wall plate to wall (wall plate is 6‘ long & bottom brace is level) Wall Plate Bottom Brace Raker Used only as temporary, spot shore. Strength is limited by bending stress in Raker or connection to ground. Wall plate is 6ft long and bottom brace is placed at right angle to wall plate Note here we show the Trough Base. It requires a sole anchor, but does not require the digging-in of discontinued U-channel base, which is less desirable Next slide discusses Trough base Note that and U-channel bases have been discontinued Design Capacity of 4x4 Flying Raker is about 1000 lb horizontal, and 1500 lb on diagonal for case where Bottom Brace is horizontal Best use Flying Raker is as initial, shore until more reliable system can be built. Rubble Use Trough Base – on concrete, paving or soil (next slide) Jun 2012

Trough Base (on conc., paving, or soil)
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Trough Base (on conc., paving, or soil) Trough Base 2-2x6x36" + 2x4x36" 7 – 16d each side Add 2x4x18"Cleat 5 – 16d to bottom, to be flush with end Add 3-2x6x18"or 2-3/4"x18"sq.Ply at soft soil Trough to Raker w/5-16d ea. side Place Picket ea. side Trough To stabilize front end May use 5/8x36" Pickets Wedges Trough Base may be used for 45 deg or 60 deg Raker. This base allows most of fabrication to be done "Away" from the wall. The Trough is adequate for the vertical component of the Raker Load (2.5k for 45 deg & 4.2k for 60deg) on paving. For Split Sole Rakers on soil, need to add the 18" sq. foot under intersection of Raker. (no need for Flying Raker) Need some sort of Sole Anch. A 6x6 is shown, but an adjacent concrete curb or any other solid surface is better Need at least 4 – 1"Pickets in Soil, plus add pickets or something to stabilize front end of Trough Sole Anchor (may pre-drill timber for pickets) 6x6 x 48"minimum long or continuous 4 – 1"x 48" Pickets into Soil, & 2 into Paving Jun 2012

Module 2a Shoring Basics Instructors Slides + Notes Full Triangle Raker - Solid Sole Type Class 3 w/bracing – on Paving or Soil 2x nailed cleat, 14-16d min. at 2x4 (20-16d with 30" cleat for 60 deg). 4x4, 4x6 Wall Plate w/ drill-ins to wall (OR plywood backing at wood or badly cracked concrete/URM walls) 4x4, 6x6 Raker depending on length and lateral & mid-point bracing 2x6 mid-braces to reduce L/d of raker Solid sole w/ nailed cleat, wedges and anchor system at end or drill-ins thru solid sole Best system, since it's most easily built away from wall and easy to adjust. Careful not to split wood in cleats due to nailing here also reduce nails from 17 to 14-16d to reduce splitting (still adequate strength) If this type of shore is used on soil (not paving), add the 18" sq foot under Sole where Raker intersects. Need at least 4 - 1" dia steel pickets into Soil, also look for a curb or adjacent wall to thrust against. You may or may not wish to bring up the discussing of nails and why we use 14 –16d, and what type of nails are recommended. The writer prefers the use of vinyl coated nails Note that the nailing of the Raker Cleat is the only place where we use nails for a direct transfer of load. Most all other nailing is for connection confinement or bracing. The value used is based on 16d Vinyl Coated Cooler Nails. They are .148" x 3.25" and do less splitting of the wood. (16d common are .162 x 3.5") The Design Value that is used is 118lb x 1.6 (increase for transient loading) = 190lb Transient loading is justified for rakers, since the loading at maximum will be by wind or aftershock See discussion of nails in Sect 2b Solid Sole Ply Gussets each side Build these away from wall and assemble at wall in pairs or more as system with lateral bracing Add 3-2x6x18" under sole on soil Sole Anchor Jun 2012

Rescue Spec Training Class built Rakers
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Rescue Spec Training Class built Rakers Class pre-built system for 90 degree, but was installed on sloped paving, so it was adjusted to fit non 90 degree angle by using 4x4 wedges Were not allowed to drill into wall or paving, so slabs were used to provide enough friction force to tighten shores. Pretty well done Jun 2012

Module 2a Shoring Basics Instructors Slides + Notes Rakers installed after Explosion Blew out part of URM cavity wall - 1 story bldg This Exterior Cavity Wall had CMU inner part, 1 1/2" insulation and 4"finish, concrete brick on outside. It was originally leaning out (as much as 5 degrees?) This was an unreinforced wall, and there were some URM partitions inside bldg. Also some metal stud walls. Some were leaning as much as 10 degrees Discuss that the bracing configuration was done so that the lower horizontal was able to be omitted for access, by adding diagonals each side of the entry Needed entry here Jun 2012

Full Triangle Raker - Split Sole Type Class 3 w/bracing
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Full Triangle Raker - Split Sole Type Class 3 w/bracing 2x nailed cleat, 14-16d min. at 2x4 (20-16d with 30" cleat for 60 deg) 4x4, 4x6 Wall Plate w/ drill-ins to wall (OR plywood backing at wood or badly cracked concrete/URM walls) 4x4, 6x6 Raker depending on length and lateral & mid-point bracing Build these away from wall and assemble at wall in pairs or more as system with lateral bracing Good choice for system where rubble covers pavement or soil next to wall. (can erect raker over some rubble) Build Raker away from wall, install Trough, and errect raker. The Trough Base is the better alternative than a U-channel, since no digging is required, and it may be used in Paving or Hard Soil where digging is difficult Probable Weak point of system is either is transfer of lateral force into ground thru U-Channel Foot or Pickets for Trough Base U-channel has been discontinued Trough Base on concrete, paving, or soil 2-2x6 Split Sole (4x4 mid block if over 7ft long) Sole Anchor Jun 2012

Class built Split Sole Rakers w/Trough Base
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Class built Split Sole Rakers w/Trough Base Example of several Rakers, including Split Sole Note use of Trough w/ Split Sole on pavement. This allows for Raker that can be built where rubble is next to wall w/o removing it Slope Bottom Brace over rubble Level Bottom Brace No rubble Jun 2012

Raker Shore Systems – Class 3
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Raker Shore Systems – Class 3 Build individual rakers away from wall & assemble as System w/bracing Rakers using 4x4 are most common and require L/d plus Lateral Bracing in order to achieve the height required to brace most URM walls Use 2x6 struts at mid height with X or V bracing Double raker is shown, is reqd to brace 2 & 3 story walls Always construct Rakers as system with lateral bracing Can reduce effective length of shores Note that one can splice 4 x 4 Rakers near bracing points. An example is shown in Manual and in the Shoring Construction Lecture SCT02b Jun 2012

Effect Of Raker Angle 1k (1000 lb) in Raker
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Effect Of Raker Angle 1k (1000 lb) in Raker .87k .5k .5k .7k .87k .7k 30 Degree 45 Degree 60 Degree Approximate Horizontal Design Capacity of Rakers Full Triangle Rakers is about 2.5 k Based on Cleat Nailing + Friction Flying Raker is about 1k For 4 x 4 Raker, due to compression plus bending Make sure class understands concept 45 deg easiest to use since cuts are same at each end of post. Often used for Solid Sole Rakers and Split Sole w/Trough Base 60 deg was used more often used for Split Sole systems with U-channel Base, since the force into the ground is larger than lateral force , but since the U-channel has been discontinued (and the Trough Base is used) 45 or 60 degrees may be used for Solid & Split Sole Rakers. Jun 2012

Split Sole - Full Triangle Raker
20ft system = 270# 16ft system = 220# Example of raker system to brace 2 story building. This is about maximum height system. Note it's 60 deg for split sole. Note we no longer notch the wall plate at intersection with Raker. Use 30" long top cleat with d The mid-height horizontal may be used to brace the wall plate, since in this cast it is 16ft (clear) long

Bracing for Raker Systems
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Bracing for Raker Systems 8'o.c. Use 5 nail pattern at 2x6 & 3 nails at 2x4 (16d) 2x6 horiz braces 2x4 or 2x6 Diagonal Braces in V or X - Use one set each 32 ft max Typical bracing V bracing is shown, but X bracing is O.K. This Diagonal bracing designed to take tension only 8 ft spacing is absolute limit to take compression forces in 2 x 6 struts Raker Bracing Elevation Jun 2012

Solid Sole Full Triangle Raker
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Solid Sole Full Triangle Raker Near tallest Solid Sole system Note: built at 45 deg since this simplifies cutting the angles. Use 24" long top cleat with d (changed in 2006 from 17-16d) 20ft system = 265# 16ft system = 225# Jun 2012

Pneumatic Shores Used As Rakers
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Pneumatic Shores Used As Rakers Raker = 2 struts + special rail Has base plate + special conn. Anchor base plate to paving w/steel bars or drill-ins. Add steel angle under base plate to bear on typical anch pl Can be used in system w/ horiz. & diag. 2x6 bracing Need to pin rail to wall. Best used as initial shore followed by wood system Use mid-brace & dbl X bracing for raker over 11ft long New systems being developed by Airshore & Paratech. 2s Jun 2012

Airshore Raker - Class 3 With mid-brace Without mid-brace
Hurst-Airshore System has fittings to allow the construction of lateral bracing. Need holes in Aluminum Rail on wall for attachment to prevent upward movement See following slides for Design Strength for a Pair of Rakers Note that Airshores are now made by Hurst Corporation and have a blue color. The photo on left shows the new mid-braced raker.

Recommended Design Strength for Hurst-Airshore Raker System – 45 deg
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Recommended Design Strength for Hurst-Airshore Raker System – 45 deg System is made from 2 rakers spaced 8ft max. apart with X-bracing. Rakers need to be attached to wall surface and restrained at ground. If raker is mid-braced (each way), use 10,000 lb. Based on Tests at CA-TF-3 w/ S.F. of abt 3 This is for 45 degrees Jun 2012

Recommended Design Strength for Hurst-Airshore Raker System – 60 deg
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Recommended Design Strength for Hurst-Airshore Raker System – 60 deg 2 rakers spaced 8ft max. apart with X-bracing Rakers need to be attached to wall surface and restrained at ground. If raker is mid-braced (each way), use 10,000 lb. This is for 60 degrees Jun 2012

Paratech Raker – Class 3 With mid-brace Without mid-brace
Paratech Raker System – photo from Tests Note that a Mid-Point Brace is now available, that should be used for Insertion point over 8ft (same as for Wood Rakers). When Mid-Point Brace is used the lateral bracing needs to have a Mid-Height Horizontal with a double set of X-bracing (same as for Wood Rakers). Mid-point brace is shown in left photo Design Strength of Paratech Rakers would be significantly higher for Insertion Points greater than 9ft is Mid-Height brace and Double Lateral Bracing is installed

Paratech Raker – Special configurations Double Raker With strut bracing
Flying Raker Paratech Raker System – Shown here are several relatively new configurations The strut braced raker does not need an X brace, since the diagonal strut has been manufactured so it can resist both tension and compression.

Paratech Raker Connection Details
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Paratech Raker Connection Details Paratech Joints had no deterioration up to Limit of Tests Jun 2012

Recommended Design Strength For PARATECH Raker System – 45 deg
System is made from 2 rakers spaced 8ft max. apart with X-bracing. Rakers need to be attached to wall surface and restrained at ground. If raker is mid-braced (each way), use 10,000 lbs. Based on Tests at CA-TF-3 w/ S.F. of abt 3 This is for 45 degrees

Recommended Design Strength For PARATECH Raker System – 60 deg
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Recommended Design Strength For PARATECH Raker System – 60 deg 2 rakers spaced 8ft max. apart with X-bracing Rakers need to be attached to wall surface, and restrained at ground. If raker is mid-braced (each way) use 10,000 lb. Based on Tests at CA-TF-3 w/ S.F. of abt 3 This is for 60 degrees Jun 2012

Tilt-up Wall Bracing Spot Shores w/conn ea end
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Tilt-up Wall Bracing Spot Shores w/conn ea end Can be used to brace reinforced concrete or masonry wall Use Drill-in Anchors for connections to wall & floor slab. Can act in Tension or Compression Available from Concrete Suppliers Some systems require bracing Jun 2012

Tilt-up Wall - adjustable pipe brace
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Tilt-up Wall - adjustable pipe brace Example - connections made using drill-in anchors. Jun 2012

Module 2a Shoring Basics Instructors Slides + Notes Tieback Systems Used to keep wall from falling when too high for Rakers Strongbacks - 4x4, 4x6, 2-2x6 Strongbacks go floor to floor Tiebacks - rope, cable, chain Extend tiebacks across bldg or tie to floor bms or columns Used when wall is too high for Rakers Double 2x system shown, can use single 4x Note: strongbacks needs to extend floor to floor Jun 2012

Tiebacks used after Loma Prieta, 89EQ By S.E. & contractor
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Tiebacks used after Loma Prieta, 89EQ By S.E. & contractor Same site as previous shown permanent rakers. These tiebacks were also used Rods connect to floor beams Jun 2012

Wood Apartments Stabilized by Rob Trost, House Mover
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Wood Apartments Stabilized by Rob Trost, House Mover On Sat following the Tue Quake, SF City required bldg owners to either hire a contractor to brace their bldgs or City would demolish them at their expense R Trost, House mover got handshake agreements from 25 of the 26 owners to perform bracing and straightening. Ave cost was $100k San Francisco bldgs as much as 24" out of plumb in 1st story - stabilize or demolish Jun 2012

26 - three & four story bldgs leaning after Loma Prieta EQ
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes 26 - three & four story bldgs leaning after Loma Prieta EQ Needed bracing or a collapse like this could occur It was mostly corner building that were leaning, since they had a "free edge" to fall into. About 36 bldgs were effected, 3 had collapsed, 7 were demolished, and 26 were braced and straightened Jun 2012

Wood Apartments Stabilized by Rob Trost, House Mover
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Wood Apartments Stabilized by Rob Trost, House Mover Diagonal 6x8x20ft shores placed from cut in sidewalk behind curb up to 2nd floor to align with floor beams. Door jambs were removed and diagonal 6x6 were added in garage openings. Rob Trost used own ingenuity, not engineered He used 6x8 since he had them in stock, and 2 men could carry one. He said he knew that would make the structures a lot more stable than they were. Jun 2012

R Trost braced this in 2hr + Using 6x8 bearing on inside of curb
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes R Trost braced this in 2hr + Using 6x8 bearing on inside of curb Contractor cut bearings into inside of curb using sledge hammer Most of this work was done in about 3 hrs Jun 2012

R Trost - Details 6x8 bearing on inside of curb up to 2nd floor
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes R Trost - Details 6x8 bearing on inside of curb up to 2nd floor Details of contractor's connections As with all Raker bracing, if quake caused the load to reverse, there is no tension connection Jun 2012

Same building by Rob Trost Similar bldg after being straightened
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Same building by Rob Trost After it was straightened Bracing was designed by S.E. to keep sidewalk clear Top After buildings were jacked back into place, this bracing was required by City Needed to keep sidewalk clear Bottom Interesting X bracing of cribbing done by another contractor Similar bldg after being straightened Note X braced cribbing Jun 2012

Most Probable Shoring For Common Bldg Types
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Most Probable Shoring For Common Bldg Types Student Manual contains suggestions for the following types of buildings: Light Frame URM - Heavy Wall TU - Heavy Wall C1 - Concrete Frame Heavy Floor PC2 - Precast Concrete Students to study on own Jun 2012

Inspection of US&R Shoring
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Inspection of US&R Shoring Should be done at each Shift Change + following any known loading change. Aftershocks, Winds, Secondary Explosion. Properly proportioned Wood Shoring should be considered as a crude Load Cell. What are the signs of Overload? Cupping of Wedges. Crushing of Header at Post. Splitting of Header at end of Overhang. Indicates about 1.5 to 2 times Design Load. These signs are not as pronounced when using Southern Pine Timber. Inspection is very important, and was done at OKC and Pentagon We can use our well proportioned, slow failure mode shores as a sort of Load Cell or Overload Indicator, as long as we know what to look for. Rescue should be asked to aid by reporting any observable problem to the StS We are not just looking to tighten the wedges, but for the signs of wood header crushing and wedge cupping that is very predictable. This will occur at from 150 to 200% of Design Load for Douglas Fir. Tests have been done on Southern Pine at Univ. of Texas in The only 4x4 timber available was cut from small logs, so each piece had the core of the tree near the middle. The performance was not as good as Doug. Fir (about 90%) and the crushing was not as obvious as for Doug Fir Jun 2012

Crushing of Header by Post
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Signs of Overload Crushing of Header by Post + Splitting of Header Cupping of Wedges Jun 2012

Inspection of US&R Shoring
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Inspection of US&R Shoring Overloading requires "Appropriate Action" by StS Overloading could indicate: More shores are needed That structure is responding differently than expected, and need to re-evaluate entire situation. That something was wrong with the original design If we discover a problem, we must take appropriate action That action should include questioning the situation and the design Jun 2012

US&R Shoring Summary - 1 Shores - strong, light, portable
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes US&R Shoring Summary - 1 Shores - strong, light, portable Support as gently as possible Need slow, predictable failure mode. Use wood posts with L/D = 25 or less Systems - positive connections & bracing Start with Class 1 (1-dimensional) Spot Shores, then progress to Class 2 (2-dimensional) Shores, and eventually upgrade to Class 3 (3-dimensional) Systems Periodic Shoring Inspection is Essential Make sure you take the time to do a good summary It is one last chance to reach the students Jun 2012

Module 2a Shoring Basics Instructors Slides + Notes US&R Shoring Summary - 2 Testing has been helpful – Part of StS2 Training Raker Shores – What is Failure Mode? Laced Posts - What configurations are better? Load at which initial "Wedge Cupping" occurs Does spaced Ply Bracing Work as well as 2x Diagonals Double Tees – Paired like Laced Posts Can they perform as well as Laced Posts to 17 ft high Cribbing – Explore ways other than friction to transfer of lateral forces. Observe just how much system deflects What amount of friction is developed between Concrete Slabs and Wood Shoring? On level or sloped surfaces Any questions? Instructor should be familiar w/disasterengineer,org There is streaming Video of Raker, Laced Post and Paired Dbl T Testing that could be shared w/class or suggested for home study Note if the video does not play on your computer, try upgrading your Flash Player Plug in by going to and download the Flash Player Plug in – you need to install it after the download Jun 2012

Review Key Learning Points - 1
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Review Key Learning Points - 1 What is Size and Type of Load that needs to be supported? The weight of the supporting structure plus its overload, or just its overload Broken Structure or Rigid Structure How much Shoring do you need? Should Shoring be similar to a Life Jacket? – providing just enough lift to keep one afloat Some portion of the load can be (is being) carried by the un-shored structure These are more Struct Spec Issues, but Rescue should understand as well These are the KEY Issues regarding How Much Shoring, which usually is not a Rescue Spec issue Jun 2012

Review Key Learning Points - 2
FEMA US&R Response System Structural Collapse Technician Training Module 2a Shoring Basics Instructors Slides + Notes Review Key Learning Points - 2 What is the Capacity for the various types of US&R Shoring Systems? How to configure US&R Shoring to ensure a predictable & slow Failure Mode How to sequence the construction of US&R shoring in order to Minimize Risk What are initial, short-term systems What are more long-term systems What are Class 1, 2, & 3 Systems What is sequence in Multi-Story Shoring? How and When to Inspect US&R Shoring These are the KEY Issues for Construction and Inspection. These issues are more important for Rescue Spec Jun 2012

Structural Collapse Technician Training-Ver. 3.1

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Structural Collapse Technician Training-Ver. 3.1

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