Centrifuge model test study on pile-anchor support system

With the increasing development of underground engineering, various support systems of foundation pits are emerging, and the pile-anchor support system is widely used in deep foundation pit engineering construction. A series of centrifuge model tests for foundation pit excavation was conducted to investigate the deformation laws of the retaining pile and the soil for pile-anchor support system. Compared with the test results of cantilever pile support system, the horizontal displacement of the retaining pile and the settlement of the retained soil significantly decreased, as well as the deformation mode of the pile and the horizontal and vertical distribution of the deformation of retained soil were different for the pile-anchor support system. The movement of retained soil tended towards the vertical due to the increasing deformation of the entire pile, further leading to the variations of the displacement distributions of the soil. The anchor limited the deflection of the pile and thus resulted in a significant reduction of soil deformation. The direction of tangential relative displacement of the anchor and soil changed during the development of the pile top displacement. Accordingly, the pile-anchor-soil interaction was categorized into three different states, which were affected by inclination angles of the anchor as well. Furthermore, it is concluded that there was an optimal inclination angle of the anchor by comparing the test results of pile-anchor support system with various inclination angles.