顺层斜坡溃屈机制与早期识别研究

摘要

This paper analyzes the mechanism of buckling failure (slipping-bending) of the bedding slope.It uses physical mechanism model, numerical simulation and theoretical analysis .It presents the forming geological and mechanical conditions, the critical failure state discrimination and early identification marks of buckling failure .It finds that the rock stratum dip angle greater than 20°is a very important geological conditions for the formation of slipping-bending.The curved uplift in the leading edge of the slope is an early sign before buckling failure .The dip angle of rock slope, the single layer thickness, the critical slope length and the depth of the buckling interact each other.The larger the rock dip angle, the more prone to produce the slipping and bending , and the more the number of layer and depth of buckling .There is a change law of negative power function between the critical slope length and the rock stratum dip angle.The flexural rigidity of bending layer and the buckling depth of bedding slope are influenced by the co-bending effect produced by the interlayer bonding .The co-bending effect plays a key role on the ultimate buckling of the bedding slope .The results have an important value for early prevention and recognition of geological hazard.%本文采用物理机制模型、数值模拟和理论计算相结合，分析研究了顺层斜坡滑移—弯曲变形机制，提出了顺层斜坡产生滑移—弯曲变形的地质和力学条件、临溃状态判别与早期识别标志。研究认为：岩层倾角＞20°是滑移—弯曲变形产生的必要地质条件。斜坡前缘岩层弯曲隆起是临溃状态的早期判识标志。岩层倾角、单层厚度、临界坡长和溃屈深度之间相互制约和影响。岩层倾角越大，越易产生溃屈，且溃屈层数和深度越大；斜坡临界坡长与岩层倾角呈负幂函数变化规律；层间黏结作用产生的共弯效应影响弯曲岩层的整体抗弯刚度，从而制约溃屈深度并对斜坡最终溃屈状态起着决定性作用。该成果对于早期防范和识别地质灾害具有重要价值。