2 Overview: Wall Categories Based on how they work:Externally StabilizedInternally StabilizedThe classification of retaining wall systems is based on the basic geotechnical mechanism used to resist lateral loads and the construction method used for the installation of the wall. The following are definitions used to classify retaining wall systems:Externally Stabilized Structures: Externally stabilized structures rely on the integrity of wall elements (with or without braces, struts, walers and/or tiebacks or anchors) to both resist lateral loads and also prevent raveling or erosion of the retained soil.Internally Stabilized Structures: Internally stabilized structures rely on friction developed between closely-spaced reinforcing elements and the backfill to resist lateral soil pressure. A separate, non-structural element (facing, erosion control mat and/or vegetation) is attached to prevent raveling or erosion of the retained soil.Soil particle at interface withback of structural facing
3 Overview: Wall Categories Based on how they are constructedCut Walls: Wall is constructed “top-down”.Cut Type Retaining Walls: Retaining structures constructed from the top of the wall to the base (i.e. “top-down” construction).
4 Overview: Wall Categories Fill Walls: Wall is constructed “bottom-up”.Fill Type Retaining Walls: Retaining structures constructed from the base of the wall to the top (i.e. “bottom-up” construction).
5 Overview: Wall Categories Highway Design ManualTable 9-6 Classification of Retaining Wall SystemsAn overview of the classification of retaining wall systems is provided in Table 9-6. The table provides a breakdown of available retaining wall systems, its associated method of construction, means of stability, design requirements and constraints (e.g. typical height range, maximum wall height).
6 Background: Proprietary Wall Systems Proprietary walls - Vendor designed systems protected by specific patents.Proprietary systems can only be used on State projects as follows:Chosen by competitive bidNo suitable alternativeSynchronization: One item only fits in a series of items, or it is part of a systemProvides a unique functionExperimental feature: Requires an approved Experimental Work PlanPublic Interest – needs project-by-project approvalProprietary retaining wall systems are vendor designed retaining wall systems that are protected by specific patents that make them unique from other retaining wall systems. Generally, this is a product, specification, or process identified in the plans or specifications as a "brand" or trade name. However, it may also be a product so narrowly specified that only a single provider can meet the specification. The term “proprietary” is really a misnomer today because many of the vendor-designed retaining wall systems that are used no longer have patents attached to them. In essence, many retaining walls could be designed using component parts from various systems, utilizing proper design procedures. For all but the simplest structures, however, this is impractical, and now, any vendor-designed and supported retaining wall system is considered a proprietary retaining wall system.Because putting an unnecessary limit on the number of competitors is essentially unfair and can potentially lead to higher prices, the policy of both the federal government and the State is not to use proprietary specifications. It is recognized, however, that there will be a limited number of special cases where exceptions to this policy are appropriate. These are indicated in the following, which is based on 23 CFR (The regulation may be viewed atThe FHWA may participate in the costs of a proprietary product under the following circumstances:Competitive bidding, provided under 23 CFR (a)(1)a. The proprietary product is obtained through competitive bidding with other suitable proprietary and non-proprietary products from multiple manufacturers. Where both proprietary and non-proprietary products are available, the STA or LPA must compose specifications that allow the contractor to choose amongst as many acceptable products and technologies as possible. If the specification lists specific products, it must list all or at least a reasonable number of products, and must include the words "or equal" to ensure the broadest range of choice.b. A competitively bid performance-based warranty specification is permitted, if it does not limit product selection to a single source. The warranty specification must clearly describe all potential products that are acceptable for use at the time of project advertisementA certification by the STA or LPA, as provided in 23 CFR (a)(2), that the specified proprietary product is either:a. Necessary for synchronization with existing facilities; orb. A unique product for which there is no suitable alternative.A proprietary item is to be used for research or for a distinctive type of construction on relatively short sections of road on an experimental basis as provided in 23 CFR (a)(3).If there are a number of acceptable materials or products, the STA or LPA may require a specific material or product when the Division Administrator approves of its use as being in the public interest as provided in 23 CFR (c). See Question and Answer #4 above.
7 Background: Proprietary Wall Systems These rules apply to any project with Federal money(incl. Pass-Thru projects & federally funded maintenance projects).Proprietary items are submitted at PS&E (with supporting documentation and justification to FHWA)A bid proposal with an item not on the AL could be declared “nonresponsive”Approved List’s with less than 3 systems require justification.The policy shall apply equally to federally aided construction and state funded work. The policy does not apply to city funded work or other work in which no federal or state funds are involved.To get approval to use a proprietary specification, it is necessary that a justification be prepared showing how the request is in compliance with one or more of the points mentioned above. This approval may be obtained only on a project-by-project basis. The FHWA has approval authority for all highway construction projects funded under Title 23 USC, regardless of whether project oversight is the responsibility of the FHWA, the STA, or the LPA. However, the FHWA may delegate approval authority to the STA for any or all of these classifications. This delegation would be formalized in the FHWA Division Office/STA Stewardship/Oversight Agreement.A responsive bid is one that meets all the terms, conditions and specification of the bid. The bid must comply with the content requirements of the bidding documents. In other words the bidder must do what the bid documents say they must do, whether it be pricing in a certain way, attending a mandatory pre-bid conference or submitting a bid bond. A non-responsive bid is a bid or offer that does not comply with the requirements as stated. Examples where a bid may be considered non-responsive include:1. Bid is incomplete2. Bid is not signed3. Bid is late4. Discrepancies in the bid
8 Background: Proprietary Wall Systems Four Proprietary Fill Type Retaining Wall Categories:Mechanically Stabilized Earth SystemMechanically Stabilized Segmental Block Retaining Wall SystemPrecast Modular Wall SystemSegmental Block Retaining Wall SystemApproved ListThe proprietary retaining wall systems now used by the Department fall within four categories; mechanically stabilized earth systems (MSES), mechanically stabilized segmental block retaining wall systems (MSSBRWS), precast modular wall systems (PMWS), and segmental block retaining wall systems (SBRWS). These walls are all considered to be “fill walls”.The current problem is that these walls are located in two different sections of the Standard Specifications and one is a special specification. In addition to this, the Department’s Approved List has 3 lists for 4 categories.It is our intent to group all like-type walls together. This levels the playing field and allows different systems to compete. The desired result is reduced cost to the Department.The change is that the designer does not choose the specific type, the Contractor does. It ‘s presumptuous to assume that all advantages and disadvantages are known for each wall system. The specific capabilities and recent developments in any wall system are best known by the individual Designer-Suppliers, who should have a say in whether or not their system is appropriate for the site conditions identified in the contract documents. Choosing a wall type simply based on an aesthetic treatment identified in a brochure does not open up competition. It’s best to place the desired treatments in the plans and allow all systems to compete.
9 FILL WALLSCurrently, personnel from the GEB, together with the Regional Geotechnical Engineer, are responsible for visiting proposed project sites and then discussing and providing Regional designers and construction personnel with the appropriate selection and design for the various wall system(s) chosen for the project. Selection of a retaining wall category for a particular site is based on the criteria established in FHWA publication “Geotechnical Circular No. 2, Earth Retaining Structures, FHWA-SA ” In general, selection is based primarily on whether a wall is going to be placed in a cut or fill section, whether a wall should or must be externally stabilized, internally stabilized, or a gravity type, and whether the wall will be permanent, temporary, or interim.The part of the selection process we are focusing on is the Fill Walls. As mentioned, it is our intent to group all like-type walls together. With this change, the designer no longer chooses the specific type, the Contractor does.
10 Merge Existing Specifications Section 554Section 632SBRWS SpecialMaterialsBureau TestingIssueEI revised Section 554 Internally Stabilized Fill Structures, incorporating some special specifications into the standards. EI revised Section 632 Precast Modular Walls, emulating the procedures defined in Section 554 for approving a wall system. Both sections refer to the Approved List for acceptable proprietary wall system designer/suppliers and outline a submittal process for approving the Shop Drawings of a particular job specific wall system design. This revision to Section 554 takes the next logical step by combining the two sections into one. Section 554 Fill Type Retaining Walls is outlined to include all fill type retaining walls (both internally stabilized fill structures and externally stabilized fill structures) which will be bid based on the height of wall. Section 632 Precast Modular Walls is deleted. The Approved List will also identify proprietary wall system designer/suppliers based on height of wall. Section 554 Fill Type Retaining Walls will still identify subcategories of walls (i.e. Mechanically Stabilized Earth System, Mechanically Stabilized Wall System, Prefabricated Wall System – both Open Top and Solid Face Units) to provide requirements for the proprietary system selected by the Contractor.An obstacle we had to surmount was the wet-cast vs dry-cast issue. Materials Bureau has worked with industry and has come up with QA process to assure quality regardless of whether the concrete is dry or wet cast.Section 554 Fill Type Retaining Walls
11 Side Issue: Testing Blocks Wet-Cast ProductsManufactured & shipped to job site in a matter of days.Based on performance criteria thru NYSDOT administered QC/QA program.Historical data of test results.Sampling and testing audit operations.Dry-Cast ProductsManufactured in lots.Quarantined for sampling and freeze-thaw testing.Delayed from shipping until acceptable test results.There are two main manufacturing processes used in the production of segmental precast concrete retaining wall blocks; dry casting and wet casting. The dry cast process utilizes a stiff concrete mixture prepared with a minimal amount of water. The stiff concrete is placed into molds and consolidated through compression and vibration. Freeze thaw durability is obtained through the high density and low permeability of the concrete.The wet cast process utilizes a plastic concrete mixture prepared with a higher water content than the dry cast process. The plastic concrete is placed into molds and consolidated through vibration. Freeze thaw durability is obtained through the use of air entraining admixtures which create a system of entrained air voids in the concrete.To incorporate both precast modular wall systems and segmental block retaining wall systems, the Department had to address the difference between masonry materials acceptance and precast concrete materials acceptance. Under current specifications, precast concrete materials are produced and accepted under a QC/QA program which allows approved manufacturers to produce, sample and test their products and then supply them to projects when specification requirements have been met. Under current specifications, masonry products are produced and accepted under a stock lot program which requires Department sampling and testing of products before they can be supplied to projects. The Materials Bureau has developed a QC/QA program for masonry materials which operates much like the precast program, allowing the two manufacturing processes to compete more competitively. Materials Procedure MP Concrete Masonry Unit QA/QC Procedures.Fairness in Testing ProceduresMaterials Procedure MP 09-03:Concrete Masonry Unit QA/QC Procedures
12 Overview: Definitions of Terms Wall SystemFace units are thestructural support.Internally StabilizedReinforcement added toa “wall system” to increaseachievable wall heights.Earth SystemReinforcement is the structural support.Face panels alone could not be a “wall system”. Wall System. A wall system is either a series of open top face units assembled to form bins which are connected in unbroken sequence or a combination of specific solid face units with a characteristic alignment and connection method, which utilize the weight of the wall system elements and the weight of the infill to resist lateral soil pressure. As indicated, the bin volume is infilled with backfill material to supplement the face unit geometry, adding to the stability of the system. Internally Stabilized Wall System. A wall system which, when constructed beyond wall heights exceeding the maximum allowable unreinforced height per the Approved List, relies on reinforcing elements within the backfill to provide stability. Internally Stabilized Earth System. A series of tensile reinforcing elements which, when placed in multiple layers within the backfill volume, improves the strength such that the vertical face of the stabilized earth volume is essentially self supporting.
13 Overview: Definitions of Terms Fill Type Retaining WallsPrefabricated Wall SystemOpen Top FaceSolid FaceMechanically Stabilized Wall System“Reinforced Prefabricated Wall Systems”Mechanically Stabilized Earth SystemPrefabricated Wall System. A PWS is an externally stabilized fill structure comprised of prefabricated face units & coping units, including leveling pads, unit infill, earth backfill, joint filler material and geotextile, and a subsurface drainage system to reduce hydrostatic pressure on the wall system.Mechanically Stabilized Wall System. When reinforcement is introduced to a PWS, they shall be reclassified as Mechanically Stabilized Wall System.Mechanically Stabilized Earth System. An MSES is an internally stabilized fill structure comprised of an unreinforced concrete leveling pad, precast concrete face panel units and coping units, earth backfill, subsurface drainage system, and reinforcing elements used to stabilize the backfill.
14 New Issuances Construction Design Standard Sheets M554-1 ( Sheet 1 of 5) Proprietary Fill Type Retaining Walls (General Notes)M554-2 ( Sheet 2 of 5) Proprietary Fill Type Retaining Walls (General Details)M554-3 ( Sheet 3 of 5) Proprietary Fill Type Retaining Walls (Typical Sections for MSES)M554-4 ( Sheet 4 of 5) Proprietary Fill Type Retaining Walls (Typical Sections for MSWS)M554-5 ( Sheet 5 of 5) Proprietary Fill Type Retaining Walls (Typical Sections for PWS)M554-6 ( Sheet 1 of 6) Geosynthetically Reinforced Soil Systems (Walls-General Notes and Details)M554-7 ( Sheet 2 of 6) Geosynthetically Reinforced Soil Systems (Walls-Typical Sections)M554-8 ( Sheet 3 of 6) Geosynthetically Reinforced Soil Systems (Slopes-General Notes and Details)M554-9 ( Sheet 4 of 6) Geosynthetically Reinforced Soil Systems (Slopes-Typical Sections)M ( Sheet 5 of 6) Geosynthetically Reinforced Soil Systems (Facing Details)M ( Sheet 6 of 6) Geosynthetically Reinforced Soil Systems (Facing Details)DesignHDM Revision No. 60 (Chapter 9)Section 9.4 Retaining Walls and Reinforced Soil SlopesEBConstruction:The existing Section 632 Precast Modular Walls included Standard Sheets outlining typical installation details and notes. These are being transferred to Section 554. In addition to these, Standard Sheets for each Proprietary Fill Type Retaining Wall was developed, along with Standard Sheets for GRSS (both Walls and Slopes).Aside:Over the years, the Reinforced Earth Company (RECo) has put several suppliers of MSES on notice to cease using “Reinforced Earth®” in their literature, drawings, web pages, and advertising as “Reinforced Earth®” is a registered trademark of RECo. Although the Department has been using Geosynthetic Reinforced Earth System (GRES) for years, RECo has requested an end to the acronym. Therefore, the terminology has been changed to Geosynthetically Reinforced Soil System (GRSS).Design:The changes to the specification required changes to the design guidance. Section 9.4 of Chapter 9 of the Highway Design Manual contains the design guidance.EB
15 New Issuances Design EI 10-031 GRSS Specification Item XX Geosynthetically Reinforced Soil System WallItem Geosynthetically Reinforced Soil System SlopeFill Type Retaining Wall SpecificationItem Fill Type Retaining Wall (0-1 m)Item Fill Type Retaining Wall (Greater than 1 m – 1.8 m)Item Fill Type Retaining Wall (Greater than 1.8 m – 2.7 m)Item Fill Type Retaining Wall (Greater than 2.7 m – 3.7 m)Item Fill Type Retaining Wall (Greater than 3.7 m – 4.6 m)Item Fill Type Retaining Wall (Greater than 4.6 m)Fill Type Retaining Wall Aesthetic SpecificationItem Fill Type Retaining Wall Aesthetic Treatment – Textured Surface (Hand Tooled, Raked, etc.), No ColorItem Fill Type Retaining Wall Aesthetic Treatment – Textured Surface (Hand Tooled, Raked, etc.), Integral ColorItem Fill Type Retaining Wall Aesthetic Treatment – Exposed Aggregate Finish, No ColorItem Fill Type Retaining Wall Aesthetic Treatment – Exposed Aggregate Finish, Integral ColorItem Fill Type Retaining Wall Aesthetic Treatment – Architectural Pattern, No ColorItem Fill Type Retaining Wall Aesthetic Treatment – Architectural Pattern, Integral ColorItem Fill Type Retaining Wall Aesthetic Treatment – Other; As shown in the Contract DocumentsEISection 554 Fill Type Retaining Walls is outlined to include all fill type retaining walls (both internally stabilized fill structures and externally stabilized fill structures) .GRSS is a non-proprietary system which is designed and detailed in the contact documents. The “XX” suffix in the wall system specification denotes facing systems.01=Welded Wire Forms02=Geocells03=TimbersProprietary systems will be bid based on the height of wall. The specification is broken up into height increments. The Approved List will identify the maximum unreinforced height available for a wall systems, along with whether a reinforced application is available (which can extend to heights up to 80’).The Fill Type Retaining Wall specification identifies a default treatment for the finished face of the chosen wall system. Aesthetic treatments applied to the face either during or after the manufacture of the units to modify the appearance of the units and of the wall as a whole may be identified in the contract documents and paid for under a separate item.
16 Aesthetics Default PWS (open top face units): Default PWS Plain, smooth concrete finishNatural concrete (gray) colorDefault PWS(solid face units):Split face finishNatural concrete (gray) colorDefault MSES:Plain, smooth concrete finishNatural concrete (gray) colorOnce the details of a wall have been completed, the aesthetics or visual impact of the system can be addressed. The designer should consult the Regional Landscape Architect to address the need for an aesthetic treatment. The specification for the fill type proprietary retaining wall has standard default treatments. If an alternate treatment is required, the aesthetic treatment is paid for separately and additional details should be provided.Proprietary fill type retaining walls may incorporate various aesthetic treatments to enhance features of the wall or blend the wall into the surrounding environment. Aesthetic treatments are treatments applied to the face of a wall system either during or after the manufacture of the units to modify the appearance of the units and of the wall as a whole. Aesthetic treatments can include modifications to color, texture, architectural pattern, the addition of exposed surface aggregate (real or artificial), the addition of simulated joints or cracks, or any other treatment or material that modifies the appearance, provided that the structural integrity, function, or life span of the wall is not negatively impacted.
17 Aesthetics Precast Panels or PWS (Open Top Face Units) PWS (Solid Face Units)Textured SurfaceExposed Aggregate FinishThe specification identifies some categories for organizational and bidding purposes. Since the Approved List allows the Contractor to choose the type of wall, the categories only provide a general idea of the type of aesthetic treatment for either a face block or face panel/unit as described below:Textured Surface: Texturing precast concrete panels or unit/modules can be achieved through formliners to develop the desired texture of grooves, ribs, ropes, or flutes. Segmental blocks may manufactured in rib configurations and split to reveal the texture of the aggregate with the ribbed appearance.Exposed Aggregate Finish: Precast concrete panels or unit/modules can achieve an exposed aggregate finish through formliners and releasing agents developing the appearance of sandblast, aggregate, or round stone. Segmental blocks are manufactured and split to reveal the texture of the aggregate.Architectural Pattern: Precast concrete panels or unit/modules can achieve an architectural pattern through formliners to develop the pattern of stacked stone, or block. Segmental blocks are themselves stacked blocks.Although the above categories provide a general idea of the type of aesthetic treatment, the specific requirements should be vividly described in the contract documents using special notes and sketches, as needed. The requirements for color, texture and pattern should use industry-standard descriptions and terminology.Architectural Pattern
18 Expanded Approved List Design AssumptionsDrycast Concrete Wall UnitsHyperlinkHyperlinkMaster ListPrefabricated Wall Systems&Mechanically Stabilized Wall SystemsMechanically Stabilized Earth SystemsBy combining all of the fill type retaining walls into one specification based on height ranges, a larger, more expansive Approved List was developed. This should aid designers by simplifying the detailing process and aid Contractors by providing approved systems based on the height of the wall shown in the contract documents.HyperlinkHyperlinkPrecast Concrete Panel UnitsPrecast Concrete Wall Units
19 Expanded Approved List 20 wall systems competitively bid against each otherDon’t Eliminate – Enumerate!Use Special Notes:EX. Notes for Use with Fill Type Retaining Walls in Underwater Applications:1. The Design High Water at elevation ___ is above the bottom of wall elevation.2. If metallic elements are used, provide additional corrosive protection to account for fluctuating water conditions throughout a 75-year design life.3. If soil reinforcing elements are used, provide certification by a NYS PE that the design accounts for the reduced resisting soil pressures under buoyant conditions.4. For any wall type, provide certification by a NYS PE that the wall will be stable under buoyant conditions.5. If ice contact is expected, ensure the durability of the wall to withstand such forces.6. Provide adequate prevention of the migration of soil through wall joints.7. Provide weep holes with inverts no more than 4” above OHW elevation and 1 ft thickness of free-draining material between OHW and DHW elevations for the prevention of hydrostatic pressure build up behind the wall due to drawdown conditions.
20 Example Approved List: Master List (MSES Portion) Wall SystemReinforced Height RangeAbutment ApplicationsHyperlinksHyperlinks
21 Example Approved List: Master List (PWS & MSWS Portion) Wall SystemReinforced Height RangeAbutment ApplicationsHyperlinksHyperlinks
22 Design Procedure Designer Determines Need for Fill Wall GEB Provides Design DetailsYesGRSS Wall?Design Elements and Specifications incorporated into Contract DocumentsNeed for Additional Aesthetic Treatment?NoNoLines, Grades, Elevations, and Special Notes Shown in Contract Documents.Design Procedure:When there is a determination that a fill wall is necessary, the first question you should ask is if a GRSS wall will be acceptable. If so, the design may be provided by the GEB. The GEB will prepare a layout of the proposed wall. The details include a plan view, elevation view and section view including existing and final grade profiles in front of and behind the wall, minimum embedment, design strength, and vertical spacing of geosynthetic reinforcement, maximum design height, installation details, right-of-way lines, temporary easements, and potential interferences (utilities).Once the details of a wall have been completed, the aesthetics or visual impact of the system can be addressed. The designer should consult the RLA to address the need for an aesthetic treatment. For these systems, a permanent facing may consist of attaching geocells or timbers. The appropriate facing details are provided with the GEB’s layout of the proposed wall.If a GRSS wall is not appropriate, the designer needs to prepare a general layout of the proposed wall for bidding purposes and identify all Special Notes to address potential design concerns. The details are to provide sufficient information for a Contractor to bid the wall and for the Contractors Consultant to perform an engineering analysis and final detailing of the wall. Typically, the general layout includes a plan view, elevation view and section view including existing and final grade profiles in front of and behind the wall, right-of-way lines, temporary easements, and potential interferences (utilities). The Contractor then selects the wall system from the Approved List.Once the details of a wall have been completed, the aesthetics or visual impact of the system can be addressed. The designer should consult the RLA to address the need for an aesthetic treatment. The specification for the fill type proprietary retaining wall has standard default treatments. If an alternate treatment is required, the aesthetic treatment is paid for separately and additional details should be provided.Vividly Describe Aesthetic TreatmentsIndustry-Standard Descriptions (Color, Texture, Pattern)Special NotesSpecial DetailsYes
23 Construction Process Plans Depict Fill Wall Plans Depict GRSS Wall Contractor Chooses Wall System from Approved ListContractor Submits Design and Details of Proprietary SystemContractor Submits Geosynthetic CertificationsConstruction Procedure:When the plans depict a GRSS wall, the Contractor shall submit the geosynthetic certifications to assure the EIC that the long term design tensile strength meets the requirements in the contract documents.When the plans depict a Fill Type Retaining Wall, the Contractor chooses an acceptable wall systems from the Approved List. He shall obtain from the chosen designer-supplier a Fill Type Retaining Wall design stamped by a Professional Engineer. The design package, including working drawings of the wall design, design calculations, and the designer-supplier’s Installation Manual is submitted to the Department (the submittal process/reviewing Bureau’s/etc. for each of the fill type retaining walls has not changed – they are outlined in § B Fill Type Retaining Wall Submittal).Submittal ApprovalNo Change in ProcessWall Construction
24 Conclusion Merging the specifications does several things: Conformance with Competitive Bidding, provided under 23 CFR (a)(1) by identifying as many acceptable products as possible.Separates the cost of the wall function from the cost of the wall aesthetics.Eliminates bias in selection of wall type.Eliminates the State losing potential cost savings to VE proposals.Eliminates the problem of the designer sometimes specifying proprietary wall systems, and then needing a spec and a “back-justification”.Where special requirements warrant, create and justify a special spec.By merging the specifications, we are developing a more expanded Approved List for all proprietary fill type retaining walls (both internally stabilized fill structures and externally stabilized fill structures). This is in conformance with #1 - Competitive bidding, provided under 23 CFR (a)(1), identifying as many acceptable products as possible.It separates the cost of the wall function from the cost of the wall aesthetics.It eliminates bias in selection of wall type. Under the current system, designers may specify a certain type of wall for project after project, and never find out if other systems provide an advantage, such as greater speed and ease of construction, at reduced cost.It eliminates the State losing potential cost savings to VE proposals. Under the old system, the designer only choose one system type, locking the other types out unless they were submitted as VE proposals. This new system allows more competition between types and brands of fill-type retaining wall. This should result in greater innovation and reduced costs to the State.It eliminates the problem of the designer sometimes specifying proprietary wall systems, and then needing a spec and a “back-justification”. Note that these are Standard Specs, designed to function in the majority of cases. However, there will be cases where special requirements warrant the creation and use of a special spec and/or procedures and methods. That’s perfectly allowable. All that’s left is to justify this course of action to the FHWA to ensure payment
25 Conclusion No change in the basic role of the RGE. In lieu of selecting a single wall type, describe the conditions, requirements and limitations of the site on the plans.More onus on the RLA.Need to vividly describe the desired aesthetic treatment on the plans using generic terms.Project Managers need to broaden their presentations of wall typesNeed to become familiar with the available categories (textured surface, exposed aggregate finish, architectural pattern) for presentations to communities. While negotiating a “look”, the PM should avoid promising the use of a specific type of wall.This does not change the basic role of the RGE. He is still responsible for determining the effect of the site and subsurface conditions on the wall selection process. The only change is instead of selecting a single wall type based on those conditions, requirements and limitations, he describes those conditions on the plans. This puts more onus on the RLA. They will need to vividly describe the desired aesthetic treatment on the plans using generic terms. Project Managers need to become familiar with the available categories (textured surface, exposed aggregate finish, architectural pattern) for presentations to communities. They need to keep in mind that the Contractor will ultimately choose the specific wall . Therefore, while negotiating a “look”, the PM should avoid promises regarding a specific type of wall and concentrate on the finish or treatment and the possible variations (joints, unit size, etc.) between wall types.