tutorial 5: excavation between two walls connected with a slab
DESCRIPTION
Tutorial 5: Excavation between two walls connected with a slab. Deep Excavation LLC. DeepXcav 2011 – Advanced course. 1. INTRODUCTION . - PowerPoint PPT PresentationTRANSCRIPT
Tutorial 5: Two walls connected with strut and base slab
Deep Excavation LLCDeepEX 2015 – Advanced course 1
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 course 2
Program layout
Wall selection
Project tree view
Design section list(right click)
General input tabsFile 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 information1. Select this button
2. Define the project name etc.
3. Press OK
DeepEX 2015 – Advanced course
Move model elevations1. 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 2nd wall2. Double click on right wall3. Change dimensions3.1 Change xwall= 60ftDepth L= 45ft
Define basic model limits (top, bottom, left, right)
1. Select this button
2. Set Top= 130ftBottom= 40ft
Left= -60ftRight= 120ft
3. Press OKDeepEX 2015 – Advanced course
Modify soil types (database of soils)1. Select this button.
Or
Expand the Soils Tree and Double click on FOptions: 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
DensityStrength
Short soil name, description and color.
Soil type & initial clay behavior
Test data for estimating soil properties
DeepEX 2015 – Advanced course
Soil type continuedSoil properties: GeneralSoil name: F (this appears in the boring)Description: Detailed soil description.Soil type: Sand gt= 125 kcf : Total unit weightgdry= 120 kcf : Dry unit weight (above water table)c‘= 0 : Effective cohesionF’= 30 degrees : Effective friction angle
v= 0.35 Poisson’s ratio
Kx = Horizontal permeabilityKz = Vertical permeability
Parameters only for claysSu = Undrained shear strengthFcv= Constant volume shearing angleFpeak= 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 S1Soil properties: Change S1A. GeneralSoil name: S1 (this appears in the boring)Description: Sand Detailed soil description.Soil type: Sand gt =125 pcf : Total unit weightgdry= 120 pcf: Dry unitc‘ 0: Effective cohesionF’ = 36 degrees : Effective friction angleV = 0.35 Poisson’s ratio
C. Elasto-plasticE = 500 ksfrEur = 3
D. BondUltimate 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 LayersTo 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 1st tieback point at the wall (x z)
DeepEX 2015 – Advanced course
Add tieback with mouse1. Select 1st point on left wall (we will modify the coordinates later 2. Select 2nd 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 3rd 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 +80 + 3ft/2 = El. +81.5• 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