Effects of soil arching on behavior of composite pile supporting foundation pit
Da‐Shuai Zhang, Xingli Zhang, Haotian Tang, Zhiqiang Zhao, Jing Guo, Honghua Zhao
Abstract
This study uses the discrete element method (DEM) to simulate the soil arching effect of composite piles supporting foundation pits during excavation and revealed the influences of small grouted steel pipe pile diameter, position, pile spacing, and friction coefficient on horizontal soil arching. The DEM simulation results show that as the diameter of the small grouted steel pipe pile decreases, the displacement arch of the soil particles between the large bored pile and the small grouted steel pipe pile evolves from a triangle to a tower shape and finally to the arch shape. When the top of the large bored piles and the small grouted steel pipe piles is in line, the stress arch between the large pile and the small pile is half of the shape of the ellipse. The stress arch between the large and large piles is in the shape of a parabola; this supporting mode is the best for different positions of small steel pipe piles. When the center of the large bored pile and small grouted steel pipe pile is in line, the stress arch between the large pile and the small pile takes the shape of a parabola, and the stress arch between the two large piles is triangular. With the increase in pile spacing, the vertical displacement of soil particles gradually decreases, the redistribution of soil particles becomes weak, and the soil arching effect becomes insignificant. The increase in friction coefficient has little effect on the geometry of the soil arch but can improve the load transfer efficiency.