Tutorial 5: Two walls connected with strut and base slab Deep Excavation LLC DeepEX 2015 – Advanced course1

DeepEX is a software program for braced excavations in soils with 2D limit-equilibrium and non-linear analysis methods, and structural verification of all elements (with AISC, ASD, Eurocodes). It offers the ability to analyze walls with multiple braces (tiebacks) in multilayered soils. The non-linear analysis considers elastoplastic behavior for the whole soil-wall-support system. The program also offers the ability to perform traditional limit-equilibrium analyses. The graphical interface is completely interactive and the input is simplified to a great extend. The program utilizes archives of wall types, structural and soil materials, ground anchors etc. The analysis can be performed in either an utlimate state or at a service state (allowable design, LRFD, or Eurocode 7 design approach methods). The program offers the ability to automatically set all critical settings according to the desired design methodology. Corso Paratie, Milano 30 settembre 2009 INTRODUCTION DeepEX 2015 – Advanced course2

Program layout Wall selection Project tree view Design section list (right click) General input tabs File menu (click) Model stages (right click options similar to excel) Command prompt (enter coordinates) Press to perform calculations. Instruction box Model space (left or right click on any item) Mouse is over item Units DeepEX 2015 – Advanced course 3D Model (Frames) View and other

Enter basic project information 1. Select this button 2. Define the project name etc. 3. Press OK DeepEX 2015 – Advanced course

Move model elevations 1. Select this button 2. Set new reference elevation to 100 ft 3. Check All boreholes (this moves all soil layers) 4. Press OK

1. Add a 2 nd wall 2. Double click on right wall 3. Change dimensions 3.1 Change xwall= 60ft Depth L= 45ft

Define basic model limits (top, bottom, left, right) 1. Select this button 2. Set Top= 130ft Bottom= 40ft Left= -60ft Right= 120ft 3. Press OK DeepEX 2015 – Advanced course

Modify soil types (database of soils) 1. Select this button. Or Expand the Soils Tree and Double click on F Options: Right click or press Delete Note: In DeepEX you can use any soil type in more than one borehole. For example the F soil can be used in boring 1 or boring 2 etc. You can use any Boring on any design section. Thus changing any property of the F soil will affect all the excavation Design Sections where F is used! Boring with F soil

Soil type data form Available soil types Add new, copy, delete, paste soil Density Strength Short soil name, description and color. Soil type & initial clay behavior Test data for estimating soil properties DeepEX 2015 – Advanced course

Soil type continued Soil properties: General Soil name: F (this appears in the boring) Description: Detailed soil description. Soil type: Sand  t = 125 kcf : Total unit weight  dry = 120 kcf : Dry unit weight (above water table) c‘= 0 : Effective cohesion  ’= 30 degrees : Effective friction angle v= 0.35 Poisson’s ratio Kx = Horizontal permeability Kz = Vertical permeability Parameters only for clays Su = Undrained shear strength  cv= Constant volume shearing angle  peak= Peak shearing angle DeepEX 2015 – Advanced course

Soil properties (Resistance and Elastic) KoNC = At rest lateral earth pressure coefficient for normally consolidated state. Enter elasticity values as shown before. Click on > buttons for more options. DeepEX 2015 – Advanced course

Soil S1 Soil properties: Change S1 A. General Soil name: S1 (this appears in the boring) Description: Sand Detailed soil description. Soil type: Sand  t =125 pcf : Total unit weight  dry = 120 pcf: Dry unit c‘ 0: Effective cohesion  ’ = 36 degrees : Effective friction angle V = 0.35 Poisson’s ratio C. Elasto-plastic E = 500 ksf rEur = 3 D. Bond Ultimate bond = 30 psi Press OK

Edit Borings (soil layers) To edit the soil layers double click on the model boring. The borings can also be edited from: a) Edit Borings Button. Or from the: b)Tree View – Stratigraphy – boreholes Double click here (or right click) with the mouse. DeepEX 2015 – Advanced course

Enter Soil Layers To edit the soil layers click on the blue button and enter the top of layer elevation. For this example type 90 here: Then select soil type S1 here: DeepEX 2015 – Advanced course Press OK

DeepEX 2015 – Advanced course

Double click on wall DeepEX 2015 – Advanced course

2. Select edit section data, to change wall properties 1. Change wall depth to 45ft DeepEX 2015 – Advanced course Number of nodes controls the divisions along the wall in a limit- equilibrium analysis. (Suggested 200 min, or set so that small intervals (0.25 ft) are generated)

Change wall section AZ 19 sheet pile 1. Change wall type 2. Select AZ-19 section 3. Select A50 steel (fy= 50 ksi) 4. Select OK DeepEX 2015 – Advanced course

Wall using AZ-19 wall section Select OK DeepEX 2015 – Advanced course

Add a new stage (Model Tab) Or right click (to add a stage, similar to Excel) DeepEX 2015 – Advanced course

Stage 1 change center El. 90 Stage 1 DeepEX 2015 – Advanced course

Add Stage 2: Add a strut at El. +92 Right click and add stage 2 DeepEX 2015 – Advanced course

You can also drag the surface with your mouse

Select tool to add a strut Note: After selecting the “Draw ground anchor button” the program tells you to select/enter the 1 st tieback point at the wall (x z) DeepEX 2015 – Advanced course

Add tieback with mouse 1. Select 1 st point on left wall (we will modify the coordinates later 2. Select 2 nd point on right wall

Edit strut section Typing PP24x0.375 will generate a pipe 24” OD x 0.375” thick wall Typing PM600x12 will generate a pipe 600 mm OD x 12mm wall

Add 3 rd stage and excavate to El. +80

Changing the water table Double click or drag the water table Change the water elevations in the general tab Click on the water table button The drop down offers other possibilities for drawing user defined water profiles.

Add stage 4: Draw in a slab between the two walls

Drawn model with slab

Edit slab properties Create 3ft thick slab Elevation refers to slab center Specify ft/2 = El Change spacing to 1ft Edit slab section to make a 3ft slab Include slab weight in vertical stress Select “Use user defined unbraced lengths” and use 10ft

Edit slab section to 3ft Slab thickness d= 36inches Slab width b= 12” Change reinforcement bars to #9 Ctop and Cbot are clearances to center of bars

Completed model with 3ft slab Green points show that slab is supported at “rigid points” Slab is not really on ground. Slab weight is added to vertical soil stresses. NOTE: EXCAVATION IS NOT YET SEALED

Change water levels and seal excavation Change water elevations to El. +90 Go to analysis tab, and apply seal excavation Purple line shows that excavation is sealed (lined). Dashed water table inside excavation shows the water potential and that the excavation is dry within.

Reviewing vertical soil stresses and water pressures: Important that total vertical stress is greater than water pressures Must maintain positive vertical effective stress Program does not consider contribution from wall side resistance and dead weight.

Review forces on slab Double click on slab Water pressure at bottom of slab: 0.62 ksf (rounded) Used FS STR= 1.6 shows the safety factor used to determine the design capacities This was defined in Design tab