Analysis of Foundation Pit Support Selection and Design Problems in Deep Soft Soil Area

Abstract

The aim of this study is to address challenges encountered in the design of foundation pit support systems for soft soil areas, which include vague calculation methodologies, insufficiently representative parameters, and limited design engineer experience. To address these issues, we conducted a comprehensive review of successful and failed case studies and observed that actual working conditions significantly impact the calculation method of soil and water pressures as well as the selection of representative strength values. Furthermore, we found discrepancies between the current calculation methods for factors such as antiuplift and overall stability and practical applications. When calculating forces like sliding torque and antisliding moment, the choice between using saturated or buoyant gravity can have significant implications. Additionally, we observed that under high pit edge loads, such as 20 kPa, the maximum bending moment in cantilever piles can significantly increase, necessitating stringent limits on these loads. Therefore, in designing foundation pit support systems for soft soil areas, it is essential to consider practical site conditions and lessons learned from previous projects. By selecting appropriate calculation methods and parameters, we can ensure the accuracy and safety of these critical structures.