Optimization of Pile Reinforcement in Soft Soils: A Numerical Analysis

To improve design rationality and deformation control of inclined-front, vertical-rear, double-row pile retaining structures in soft soil, we consider the foundation pit of the Xiantao Citizen Service Center, Hubei, China. We aim to numerically optimize pile reinforcement configuration in soft soil. Based on on-site measurements and finite element simulations, we study front pile angle, tie beam–soil interaction; range, depth, and elastic modulus of inter-pile soil reinforcement; pile displacement; bending moment; mechanical properties of pile displacement; pile displacement; bend moment; etc. We conclude that (1) inter-pile soil reinforcement strongly influences overall pile displacement, and the tie beam restricts local pile top displacement; (2) optimal deformation control is achieved when reinforcement depth is 1 to 1.5 times excavation depth; and (3) an elastic modulus of 200 to 300 MPa for reinforcement is best for displacement control. These results provide theoretical and practical guidance on parameter optimization and engineering design of similar soft-soil support structures.