The laterally static loading test of the closed rock-socketed diaphragm walls

Closed diaphragm walls, when used as long-term foundations, demonstrate exceptional lateral bearing capacity. Relying on a specific project in Shenzhen, a lateral static loading test was conducted on rock-socketed enclosed diaphragm walls. The test monitored the displacements at the wall top and lateral geotechnical resistance using pre-installed instruments. During the experiment, the maximum applied load reached 80500 kN, representing the largest lateral static loading test conducted worldwide to date. The experimental results reveal that the load-displacement curve of the rock-socketed closed diaphragm wall exhibits a gradual and nonlinear characteristic. Throughout the loading process, the wall experienced both horizontal and vertical rotations, with horizontal rotation primarily caused by the uneven distribution of rock layers on-site. The lateral geotechnical pressure along the depth showed a trend of initially increasing and subsequently decreasing, with the maximum pressure observed at a depth of 0.28 times the wall depth. The distribution of lateral geotechnical pressure was significantly influenced by the position of the vertical rotation point, which was located in a relatively shallow rock layer. Furthermore, no resistance was provided by the enclosed soil, and the enclosed rock resistance was notably reduced compared to the surrounding rock resistance. Specifically, the enclosed rock resistance of moderately weathered granite was approximately 0.73 times that of the surrounding rock, while the enclosed rock resistance of slightly weathered granite was approximately 0.63 times that of the surrounding rock.