布沼坝露天西帮边坡破坏机制的数值模拟分析
2012-06-04李春生张保林
李春生张保林
摘要:针对布沼坝露天西帮边坡复杂构造及其下部煤炭资源待开发的特点,本文应用三维弹塑性数值模拟方法,模拟了下部煤炭开采后边坡岩体的滑移破坏机制,得到了上部山坡以弧型滑移破坏为主、中间坍塌和下部顺层滑移“三段式”破坏模式,整体与局部连锁式循环嵌套破坏特点,因此,要保证边坡的稳定状态,需要控制下部顺层滑移量或削减上部岩体自重荷载为主,以便减小边坡岩体的变形和破坏。
关键词:数值模拟,破坏机制,滑坡,变形
Abstract: For the west slop of Buzhaoba open pits complex structure and the characteristics of its lower coal resources to be developed, in this paper, three-dimensional elastic-plastic numerical simulation method is applied to simulate the slip failure mechanism of the slope rock mass in the lower part of the coal mining, and has obtained "three-stage" failure mode which is expressed as the upper parts curved slip damage, the middles collapse and lowers bedding slip and whole and the local chain loop nest damage characteristics. Therefore, to ensure the steady state of the slope, need to mainly control the lower part of the bedding slip or cut the dead weight load of the upper rock mass, in order to reduce the deformation and failure of rock slope.
Keyword: numerical simulation; failure mechanism; landslide; deformation
中图分类号:U416.1+4文献标识码:A文章编号:
1、 工程概况
布沼坝露天矿西帮边坡是由自然山坡和下部人工开挖边坡共同组成,累计高度为340m,由于受F7、F8断层构造的影响,使原地层倒转,导致T2g1和T2g2灰岩段成为煤层N3的上覆岩层(见图1),从而形成了以粘土岩为基底的高大边坡,导致深部煤层开采诱发边坡岩体的剧烈变形和破坏;然而,如何保障开采过程中边坡安全就成了安全生产的关键技术问题,为此,本文运用数值模拟的方法对西帮边坡进行了数值模拟分析,以便研究西帮开挖后边坡岩体的变形与破坏机制,从而为后续深部开采提供依据。
2、特殊地质构造影响下边坡岩体破坏机制的数值模拟分析
2.1 计算模型设计
根据西帮边坡工程地质特性,本次数值模拟以西帮346剖面为中心,宽度向南北两侧各延伸200 ,长度取1000 、高度取400 。模型尺寸为 。模型地层包含新第三系东升桥粘土岩段、主煤段、泥灰岩段、薄煤层粘土岩段等。……
