基于p-y曲线法的承重阻滑桩内力及位移分析

INNER-FORCE AND DISPLACEMENT ANALYSES OF LOAD-BEARING AND ANTI-SLIDE PILES BY p-y CURVE METHOD

承重阻滑桩在山区高速公路建设中应用广泛,具有承重与阻滑双层作用,其受力性状远比抗滑桩和平地上受荷桩复杂,此外,桩岩(土)之间的相互作用呈非线性特征,传统的有限元方法建模较为复杂且难以收敛。通过对此类基桩受力特性及荷载传递机制的深入探讨,将桩周岩(土)体视为外部荷载施加,并采用p-y曲线描述桩–岩(土)界面接触的非线性问题,建立考虑多种影响因素的微分方程并得到相应的有限差分解。实例分析表明,以该方法分析承重阻滑桩的内力及位移是可行的,其计算简捷,精度较高,便于工程实际应用。

Load-bearing and anti-slide piles have a popular application in the construction of freeway in mountainous area with double functions： not only bearing the load from the superstructure but also counteracting landslide-thrust from the side of pile foundation; and the mechanical behaviors of piles are much more complex than anti-slide piles or simplex inclined-loading piles. Moreover, the interaction between pile and surrounding rock or soil is highly nonlinear, which makes it complicated for traditional finite element method to build analytical model; and the computing result is hard to converge. Based on the deep research of load transfer mechanism and stress characteristic for this kind of piles, the action of rock or soil around piles is regarded as external load, and the p-y curve is adopted to describe the nonlinear behavior of contact between piles and surrounding rock or soil. Therefore, a differential equation considering some influencing factors is set up with the corresponding finite difference solution being obtained as well. Application to an engineering case shows that the method is forthright, accurate and feasible to engineering application.