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Bored pile wall example with DeepXcav (reinforced concrete piles)

A bored pile wall example will be analyzed with DeepXcav. The following data is available:

a) Soil properties: Sand, friction angle = 30 degrees, total unit weight 120 pcf, loading modulus of elasticity Eload= 300 ksf, reloading modulus of elasticity Eur = 900 ksf. Ultimate bond resistance for ground anchors 40 psi.

b) Excavation depth: 25 ft, cantilever stage 10 ft, ground anchor at 8 ft depth at 15 degrees. Bored piles spaced at 2.5 ft off center. Include 600 psf traffic surcharge 1 ft behind the wall for a length of 20 ft.

Objective: Design the bored pile and the ground anchors with allowable stress methodology and obtain a wall embedment safety factor of 1.5.

The following image shows the final bored pile wall model as constructed in DeepXcav. The image also shows the horizontal wall displacement and the wall bending moment at the final excavation stage. The red lines next to the wall moment represent the bending moment design wall capacity.

Bored pile wall example with DeepXcav

First we change our wall section to a bored pile wall. We double click on the wall, then select a tangent pile wall with reinforced concrete:

Bored pile wall properties with DeepXcav

We then apply the US allowable design standards from the Design tab:

Apply US allowable settings with DeepXcav for a bored pile wall

Next, from the Analysis tab we will set the available wall friction at 50% of the available soil friction:

Wall friction on bored piles in DeepXcav

Next, we will install the ground anchor on stage 2 and also place the traffic surcharge behind the wall:

Install ground anchors in DeepXcav on a bored pile wall

We then analyze the excavation example and inspect the initial results. The items in red demonstrate that the tieback is overstressed by about 15%.

Bored pile wall analysis results with DeepXcav

Next we will optimize both the tiebacks and the wall properties:

Optimized bored pile wall properties with DeepXcav