裙结构对裙式吸力基础水平承载性能的影响

Effects of the Skirted Structure on Lateral Bearing Behavior of Skirted Suction Caissons

通过饱和细砂中裙式吸力基础的水平单调加载模型试验,探究了裙结构对基础水平承载力及土压力分布的影响.结果表明：不同加载高度下,与传统吸力基础相比,裙式吸力基础水平承载力显著提高,有效控制了基础的水平位移,且基础水平承载力随着裙高、裙宽的增加显著增加;不同条件下基础的归一化荷载-水平位移关系曲线可用同一公式表示.基础周围土压力的发展与基础的水平位移有密切联系,相比于裙宽对土压力分布的影响,裙高的变化对于主桶周围土压力分布的影响更为明显.此外,根据净土压力沿深度方向的分布规律,确定水平荷载作用下基础转动点约位于0.6～0.7倍的主桶埋深处.

Effects of the skirted structure dimensions on lateral bearing capacity and the distribution of earth pressure were investigated through model tests conducted in saturated fine sand. The test results prove that compared with the traditional caisson,the skirted suction caisson can control the deflection more effectively, and its lateral bearing capacity increases to a greater extent with increasing length and width of the skirted structure. A unique relation was established between lateral load and deflection in the normalized form. It shows that there is a good relation between earth pressure mobilized and deflection of caissons,and the earth pressure is more sensitive to the skirt length than the skirt width. In addition, the net earth pressure distribution method was employed to determine the position of ro- tation center,which is approximately at a depth of 0.6-0.7 times the main structure length.