顺层边坡岩体结构的后屈曲分岔特性

The post-buckling bifurcation characteristics for side slope with stratified rock mass

在已有利用初始后屈曲理论和尖点突变理论对顺层边坡岩体结构进行性态分析的基础上,结合顺层边坡岩体结构弯曲变形及溃屈破坏的特点,运用几何非线性大变形理论对顺层边坡岩体结构的后屈曲非稳定性态进行研究,给出了顺层边坡岩体结构发生溃屈破坏的判据。同时求出了顺层边坡岩体结构发生溃屈破坏时的屈曲模态幅值,并给出了工程实例。研究表明:可以运用几何非线性大变形理论来求解顺层边坡岩体结构的溃屈破坏极限长度,进而求出其发生溃屈破坏时的模态幅值;此模态幅值代表了结构体系在屈曲状态下模态幅值的最小值或跨越分岔集发生溃屈破坏的模态幅值的最大值,具有临界模态幅值的二重性的基本特征;由于沿边坡方向重力分力的影响,倾斜层状边坡发生溃屈破坏的位置会下移,在确定溃屈破断的位置时,可以运用二分法的思想。

Combining the bending and buckling failure characteristics of the side slope with bedding rock mass,the post-buckling unstable behavior is studied by using geometric nonlinear large deformation theory on the basis of previous research using the initial post-buckling theory and the cusp catastrophe theory. Not only the criteria for buckling failure of rock mass bedding slope is proposed,but the post-buckling mode amplitude for side slope with bedding rock mass is solved. An application example is given at the same time. The results indicate that the geometric nonlinear large deformation theory can be used to solve the limited length of buckling failure to obtain the mode amplitude which represents the minimum mode amplitude of the structural system under the buckling state or the maximum mode amplitude when the structural system spans the bifurcation set and buckling failure occurs; due to the influence of gravity force component along the direction of the slope,the position where the buckling failure occurred will move down. The dichotomy iterative ideological can be used when determining the asymmetric breaking position.