考虑竖向摩阻力的抗滑桩嵌固段内力计算

Internal force calculation of anti-slide pile socketed segment considering vertical frictional resistance

抗滑桩变形过程中产生的竖向摩阻力可以形成反力矩,有助于抵抗滑坡推力,现对竖向摩阻力对抗滑桩嵌固段内力及变形的影响进行研究。在弹性地基系数法K法和小变形假设的基础上,假定竖向摩阻力与桩岩相对位移成正比,建立考虑竖向摩阻力的抗滑桩受力模型及其挠曲变形微分方程,并推导其求解过程。通过马家沟Ⅰ号滑坡抗滑桩实例计算,分析了竖向摩阻力对抗滑桩内力及变形计算的影响。竖向摩阻力形成的反力矩能减小抗滑桩的变形及内力,对抗滑桩剪力的影响最大,水平位移次之,对弯矩影响最小。考虑竖向摩阻力的抗滑桩计算模型能改善目前抗滑桩设计中剪力计算过大的问题,使抗滑桩设计更为合理。

The vertical frictional resistance generated during the deformation of anti-slide pile can form anti-moment or push-pull resistance, which can contribute to landslide prevention. The impact of the vertical frictional resistance on the internal forces and deformation of anti-slide pile socketed section is studied. On the base of elastic foundation coefficient method“K method”and small deformation assumption, the vertical frictional resistance is considered proportional to the relative displacement of pile and rock mass, then the mechanical model and the bending deformation differential equations of anti-slide pile are established. And the corresponding solution process is derived. The effects of the vertical frictional resistance on anti-slide pile are analyzed by the calculation of anti-slide pile in Majiagou landslide #1. It is found that the counter torque formed by vertical frictional resistance can reduce the pile deformation and internal forces, the shear force is affected by the counter torque mostly, followed by the deformation, and little influence is brought to the bending moment. The anti-slide pile model which has taken the vertical frictional resistance into account can improve the problem of excessive shear force when using the current method, and make the design more reasonable.