Feasibility study on cushion replacement support for pipe gallery foundation pit in typical soft soil strata
This study addresses the complexities and inefficiencies associated with traditional support replacement methods, specifically their impact on construction continuity and the efficiency of pipe gal-lery structures. A new method using cushion replacement support is proposed, based on the typical soft soil strata and a case study of a deep foundation pit project for a pipe gallery in Zhongshan, Guang-dong. Firstly, a three-dimensional Abaqus numerical simulation of the foundation pit is conducted and compared with measured data for analysis. Then, the cushion replacement support method is pro-posed, and numerical simulation orthogonal experiments are conducted to explore the influence of dif-ferent factors on the deformation of the foundation pit enclosure structure after support removal. Fi-nally, the feasibility and rationality of the proposed cushion replacement support method are verified through on-site experiments, and its impact on the horizontal displacement of the retaining structure is compared to that of traditional methods. The research results indicate that the three main factors influ-ence the deformation of the retaining structure: the thickness of the improved cushion (cushion beam), the strength grade of the concrete, and the diameter of the longitudinal steel bars. Among these, the thickness of the improved cushion (cushion beam) has the largest range, serving as the most significant factor affecting the deformation of the retaining structure. The on-site experiment of the cushion re-placement support method shows that the average measured maximum horizontal displacement of the retaining structure is only 21.79 mm after the removal of the bottom horizontal brace. This effectively solves the issue of excessive deformation in soft soil areas and confirms the applicability of the cushion replacement support method. Under the same geological and excavation conditions in the foundation pit, the maximum horizontal displacement of the retaining structure using the cushion replacement sup-port method is about 84％ of that using the traditional method, demonstrating better control over de-formation of the foundation pit compared to traditional support replacement methods.
deep foundation pit in soft soilAbaqus numerical simulationcushion replace supporton-site monitoringdeformation of the enclosure structure
万方数据
维普
