嵌岩桩摩阻力数值分析法工程应用研究

Engineering Application of the Numerical Analysis Method on Rock-socketed Pile Friction

以自平衡试验实际工程为背景,对嵌岩桩侧摩阻力进行数值模拟分析,提出确定嵌岩桩承载力的新方法。将嵌岩桩桩-岩摩擦假设为库仑摩擦模型,通过确定与模型相关的粘结力c、摩擦系数μ、切向接触刚度k参数,求解并绘制各级荷载作用下Q-s(荷载-桩端位移)曲线、Q-σ(荷载-指定截面应力)曲线,通过对比各参数变化对曲线形态的影响来调整模型参数,以使求解的曲线与试验实测的曲线相符合,即可认为所模拟的桩—岩模型与实际嵌岩桩相符合,最后可通过对模型施加桩顶荷载确定嵌岩桩的承载力。该应用研究表明可通过确定的粘结力c、摩擦系数μ、切向接触刚度k参数用数值模拟方法计算出同一岩层场区内不同桩径及不同嵌岩深度的嵌岩桩承载力,具有工程指导意义。

With the self-balanced test project as background, the numerical analysis on rock-socketed pile friction is carried out, and a new method of bearing capacity of rock-socketed pile is put forward. The rock-socketed pile friction is supposd as the Coulomb Friction model. By determining the cohered force c, the friction coefficient/z, the tangential contact stiffness k, Q-s （load-displacement of pile bottom） and Q-o- （load-specified section stress） curves under different loads are derived. Adjusting the parameters of the model according to the influences of the parameters to the curve shape, so the drawing curves fit with the experimental curves, which can think that the model corresponds to the rock-socketed pile. Finally, the bearing capacity of rock-socketed pile is determind by applying load on the pile top. The significance of this application study show that it may calculate the bearing capacity with different pile diameter or different socketed depth through the cohered force c, the friction coefficient μ, the tangential contact stiffness k in the same rock area,and it has the conducting significance.