The behavior of contiguous pile wall supporting deep excavation in cohesive soil: A parametric study using finite element.

Vertical space expansion is common amid rapid development and limited space in dense urban areas, which causes the widespread use of high-rise buildings and underground spaces. A contiguous pile wall (CPW) is an alternative reinforcement to overcome the complexity of underground structures excavation due to space limitations. This reinforcement is easy to implement and relatively does not disturb the surrounding environment. This study discusses a parametric analysis of basement excavation with contiguous pile wall (CPW) reinforcement using finite element (FE). The parametric analysis focuses on comparing the effect of variations in excavation depth (He) and the ratio of excavation dimensions (L/B) on lateral displacement (Ux) and bending moment (Mx) behavior of CPW reinforcement in 3-D and 2-D conditions. Analysis was performed on a 3-D model using Rocscience RS3 and 2-D with RS2. The model is determined as a square excavation on dry silty clay soil. The diameter of the pile (d) used is 0.80 m, with the spacing between the piles set at 1.00 m. The wall penetration (D) is adjusted based on the variations of the excavation depth (He). The results show that the depth (He) and dimension ratio (L/B) of the excavation had a significant effect on the lateral displacement (Ux) and bending moment (Mx) of the pile. Increasing the depth of excavation (He) tends to increase the lateral displacement (Ux) and bending moment (Mx) of the pile, although the wall penetration (D) also increases. Simplification of the deep excavation model under 2-D conditions due to analysis limitations tends to give overestimated values of lateral displacement (Ux) and bending moment (Mx) compared to 3-D analysis based on variations in depth (He) and dimension ratio (L/B) of excavation, although the behavior of the 3-D excavation model with dimension ratio (L/B ≥ 4) is close to the behavior of the 2-D plane strain model. [ABSTRACT FROM AUTHOR]