水平-竖向耦合荷载下单桩承载性状数值分析

Numerical Analysis of Bearing Behavior of a Single Pile under Combined Vertical and Lateral Loads

为了研究单桩基础在水平-竖向耦合荷载下的承载性状,以工程实例为基础,通过数值计算的手段建立了均质海相软黏土层中单桩受耦合荷载的计算模型,研究均质土层中竖向与水平耦合荷载作用下单桩的承载力、变形特点。结果表明:当施加的水平力未超过临界荷载,水平力的施加对单桩竖向承载力无影响;当施加的水平力超过临界荷载,水平力的施加对单桩竖向承载力有着不利的影响;水平力的施加延缓了竖向抗拔承载力破坏点的出现,且随着施加的水平力的增大,抗拔极限破坏点出现得越晚,水平力的施加提高了单桩抗拔承载力;预先施加竖向力会减小水平力产生的桩顶水平位移,提高单桩水平承载力;且存在一个最优的竖向荷载,使得桩顶水平位移最小,桩身弯矩最小。

In order to study the bearing behavior of single pile foundation under horizontal vertical coupling load,the calculation model of single pile based on the engineering example in homogeneous marine soft clay layer was established by numerical calculation.The bearing capacity and deformation characteristics of the single pile were studied.The results show that the horizontal force exerts no influence on the vertical bearing capacity of single pile when the applied horizontal force does not exceed the critical load.When the applied horizontal force exceeds the critical load,the horizontal force exerts a negative effect on the vertical bearing capacity of the single pile.The application of horizontal force postpones the occurrence of the failure point of vertical uplift bearing capacity,and with the increase of the applied horizontal force,the failure point of the uplift limit appears later.The application of horizontal force increases the uplift bearing capacity of single pile.The horizontal displacement produced by the horizontal force will be reduced and the horizontal bearing capacity of the single pile is increased by applying the vertical force in advance,and there is an optimal vertical load,which makes the horizontal displacement of the pile top minimum and the pile bending moment minimum.