Stress and Deformation Analysis of Green Prefabricated Slope Surface Protection Structure for Deep and Large Foundation Pit

Abstract

Objective Excavation of deep and big foundation pit destroys the equilibrium state of the original stress field in the soil, leading to ground deformation. Foundation pit deformation can be controlled by adopting GRF (green prefabricated ) surface protection structure with the premises of green environmental protection and high construction efficiency. An in-depth research on stress performance and deformation properties of GRF surface protection structure for deep and large foundation pit is required. Method Relying on the deep and large foundation pit project of Nanning International Airport Comprehensive Transportation Hub, a combination of finite element numerical simulation and on-site measurements is employed to study the stress and deformation law of the GRF surface protection structure for foundation pit top slope and the GRF surface protection structure between retaining piles in foundation pit. Result & Conclusion With the increase in foundation pit excavation depth, the location of the maximum lateral displacement of foundation pit top slope gradually shifts towards slope toe, with a maximum lateral displacement of 8.67 mm. The use of GRF surface protection structure effectively enhances the stability of foundation pit top slope. Anchor rods help transfer part of the load borne by GRE surface layer to the soil layer, thereby reducing deformation and stress GRF surface layer. The spacing between retaining piles has a great influence on soil arching effect. In this project, retaining pile spacing can be increased to around 2.5 m, and soil arching effect is most obvious at 7-8 meters below the pile top.

Keywords

• deep and large foundation pit
• slope surface green prefabricated protection structure
• stress
• deformation