软弱基座型高边坡危岩演化及应力场分析

Abstract

危岩崩塌具有爆发突然、难以预测、危害性大等特点，准确合理推断危岩崩塌演化发展过程及趋势成为预防和治理危岩崩塌的关键性问题。以黄泥堡高边坡危岩为依托，结合现场工程地质调绘，通过分析高边坡危岩体的结构特征，得出近水平层状软弱基座型危岩体悬臂–拉裂式破坏模式；运用地质学基础理论，分析阐述高边坡危岩体崩塌的形成及演化发展过程的四个阶段；在此基础上，推导出评价危岩崩塌稳定性的表达式；采用数值模拟方法对依托工程实例进行应力场模拟分析，研究地应力场的演化特征。结果表明，岩腔底部产生应力集中现象，并且随着岩腔的发展加深而越来越明显。为高边坡危岩稳定性评价以及治理措施提供指导和借鉴。 Perilous rock and collapse is provided with characteristics of sudden outbreak, unpredictable, harmful and so on, accurately and reasonably infer the process and trend of the evolution of pe-rilous rock and collapse is the key issues for the prevention and treatment of rock collapse. In this paper, based on the high rock slope of Huang Nibao, combined with the site engineering geological mapping, the structural features of dangerous rock mass in high slope is analyzed, and the cantilever-rupture failure mode of the near horizontal layered perilous rock in soft foundation is obtained. Based on the basic theory of geology, the four stages of the formation and evolution of the perilous rock and collapse are analyzed and explained. On the basis of this, the expression of the stability for the perilous rock and collapse is derived. Based on the engineering example, the numerical simulation method is used to analyze the stress field, and study the evolution characteristics of the stress field. The results show that, the stress concentration occurs at the bottom of the rock cavity and becomes more and more obvious as the rock cavity deepens. It provides guidance and reference for the stability evaluation and treatment measures of perilous rock in high slope.