Analysis of Secant Piles on PYWALL

[pelelo]

Hello,

I am analyzing on PYWALL which would be the optimum diameter for a secant pile wall project I am working on. Please refer to the attached sketch.

Four (4) stages are shown: 1) End of secant pile drilling process, 2) removal of the material in order to place the bottom slab, 3) placing a top slab and then 4) placing a classified backfill material, being the last stage.

I am not sure how to assign deformations or slope values on PYWALL as I assume at each slab location a deformation or a slope value is necesary. Is it ok if I run stage 1 (secant piles + excavated material) until bottom slab level then verify the actual deformation at that level and then RUN a STAGE 2 specifying that deformation value (obtained in STAGE 1) at the bottom slab level? (this will simulate the bottom slab installation).

Then, on this stage, I will verify again the deformations on the top slab level and the RUN PYWALL again on the 3rd stage and specify the deformation values obtained on STAGE 2 for the top slab level and specify this new value on this 3rd stage? (simulating the top slab construction)

Of course there is a 4th stage which is the backfill placement, I am not sure exactly what values of deformation or slope I need to enter as the backfill will be placed on a 7 m depth.

Does all this make sense?. Please let me know your inputs, Thanks.

 

[FixedEarth]

What type of structure is this? Below the 20m, what is your embedment depth and what is your reinforcement on alternate piers?

You can this by hand or set up a spreadsheet to get rough estimates before modelling it on a software. You can use the center to center of beam as your spacing and assume the middle pier is lagging. Then just use triangular active earth pressure + any surcharges on the 20 ft cut and use passive resistance to determine your required embedment.

20m is very tall height for a cantilever system, which is what we have at stage 1. You will need rakers or struts at heights above the 20m level. However, I am thinking slurry wall might be more appropriate system. If you get it to work, attach your calculations so we can see your assumptions.

 

[InDepth]

Should be able to install structs that are embedded in the final slab.