基于拱效应的露天顺向岩质边坡开采影响范围的确定

Determination of the Influence Scope of Opencast Mining in Bedding Slope Based on Arch Effect

顺向开采岩质边坡极易产生顺层滑动,对坡上及坡下建(构)筑物通讯或输电设施以及风景名胜等构成威胁,因此开采前须对边坡的开采影响范围作出合理的评估。本文首先从土拱的形成条件出发,分析了露天顺向开采岩质边坡岩拱效应的存在,同时结合岩土性质对土拱和岩拱的特性进行了对比分析,在此基础上建立了岩拱效应分析的基本假设条件及计算模型,并利用结构力学两铰拱理论对岩拱的拱轴线、拱圈应力、弯矩值等进行了计算;然后根据岩拱轴线和拱圈厚度求得拱圈内缘线及外缘线,并利用拱圈内缘线、外缘线及开采边界将露天顺向开采边坡划分为4个区;最后结合各区对建(构)筑物影响的强烈程度,求得最大滑塌高度及开采边界距离开采影响范围线的水平距离,从而获得露天顺向岩质边坡的开采影响范围。

Based on the formation conditions of soil arch effect, this paper proves that rock arch effect exits in opencast mining,analyzes and compares the rock arch characteristics of different rock masses, sets the basic assumptions for the analysis of rock arch, and calculates and studies the shape of arch-axis, the inner stress of arch and the moment of rock arch by applying the two-hinged arch theory in structure mechanics. For the purpose of dividing the region of bedding slope into four parts by the boundary of inner line, outer line and exploitation border, the paper ensures the inner and outer lines based on the arch axis and arch thickness. Finally,the paper calculates the maximum sliding height and distance between the exploitation border and incidence scope of opencast mining and analyzes the incidence scope of opencast bedding slope by considering the influence extent to buildings from every part.