关键词: 沉管隧道, 大型干坞, 放排水, 边坡稳定性, 数值模拟, 渗流, 浸泡

Abstract:

Numerical simulation is made by means of ANSYS software and field monitoring data is used to modify the theoretical methods, so as to study the stability of the side slopes of large dry docks during water filling and water discharging under complex conditions. Conclusions drawn are as follows: 1) The course of the water absorption and water drainage of the side slopes are completed almost at the same time with the water filling and water discharging.The deformation of the side slopes in the water absorption period is larger than that in the water drainage period, and the water absorption velocity of the side slopes is larger than than of the water drainage velocity. Due to the water containing capability of the side slopes, the maximum difference between that of the water head in the side slope and that in the foundation pit at local positions reaches 4m, which jeopardizes the stability of the side slopes; 2) While anchor bolts and anchor cables can play a passive role in the control of the slope slide, they can play little role in the control of the deformation of the slopes; 3) While anchor bolts and anchor cables can improve the integrity and strength of the soil mass of the potential slide plane, they can make the internal rigidity of the soil mass of the slopes discontinuous and can induce large yielding stress and deformation at local positions; 4) The accumulative deformation at both wings of the slopes are larger than that at the central point of the slopes. Under the action of the water heads inside the slopes and outside the slopes, the deformation at both wings of the slopes induced by water absorption and water drainage is different, due to the different restraining means at both wings.

Key words: immersed tunnel, large dry dock, water filling and water discharging, slope stability, numerical simulation, seepage, saturation