Analysis on Bearing Mechanism of T‐Shaped Pressure Cast‐Situ‐Solidified Soil Pile With Spray Expanded Frustum

ABSTRACT T‐shaped pressure cast‐situ‐solidified soil pile with a spray‐expanded frustum (T‐PSPSF) is composed of fluidized solidified soil, and features distinct upper and lower pile sections with varying diameters, an expanded body with double‐frustum (EBDF), and ribbed plates. T‐PSPSF exhibits superior performance including high bearing capacity, enhanced construction productivity, and notable economic and environmental benefits. Based on the laboratory test results, the mechanical parameters of the pile are clarified. The geometric configuration of the pile was determined through field tests. For practical purposes, the diameter prediction method of EBDF is proposed. Additionally, numerical simulations were conducted with varying diameters, heights, and positions of EBDF, as well as different ratios of upper pile diameter to lower pile diameter, to determine the optimal pile structure. The load‐sharing ratio of the EBDF to the total pile head load exceeds 50%. Considering both the bearing characteristics and economic efficiency of the T‐PSPSF, the optimal diameter of EBDF is adopted as 1.4 D , the optimal length is 1.0 D , the optimal position can be adopted between 5 D and 7 D above the pile head, and the optimal ratio of upper pile diameter to lower pile diameter is taken as 0.5.