Research on Soil Displacement and Adjacent Pile Response Caused by High-Pressure Jet Grouting Pile Construction in Loess Areas

This study analyzed the soil displacement effect during high-pressure rotary jet pile construction by simplifying the construction process as a series of pressure-controlled spherical cavity expansions in a semi-infinite soil medium. Based on the elastic-plastic solution of pressure-controlled spherical cavity expansion theory， a calculation method was proposed to estimate the soil displacement caused by high-pressure rotary jet pile construction. Nonlinear contact theory between the pile and soil was introduced， and the finite difference method was employed to determine the internal forces and deformations of the pile. The proposed method was applied to field construction cases， and its validity was verified by comparing the results with on-site monitoring data. Additionally， a parametric study was conducted. The research findings revealed that the soil displacement effect decreased with depth and primarily occurred in shallow soil layers during the construction of individual high-pressure rotary jet piles. The lateral displacement at the ground surface increased first and then decreased with the increase in horizontal distance， while the ground uplift exhibited an exponential decay trend. The maximum lateral displacement of existing piles was observed at the pile head， and the maximum bending moment occurred in the middle section of the pile. The construction time interval had the greatest influence on the response of adjacent piles. Therefore， to mitigate soil displacement effects， it is recommended to adopt construction techniques such as skip-hole drilling and spaced pile installation.