节理岩质边坡随机块体搜索的一种简便方法

摘要

A large number of random blocks mainly formed by the combination of discontinuities and slope surface can be found in the jointed rock slopes.According to the combination between discontinuities and slope surface,the random blocks are divided into three types:block sliding through double sides on slope shoulder,block sliding through double sides on slope surface and block sliding through single side on slope surface.The method of "field qualitative judgment plus stereographic projection" is used to identify the type of random blocks.On the basis of detailed field sampling of discontinuity,three-dimensional discontinuity network simulation is performed by using geological statistics and computer technology.On the basis of former researches on obtaining the diagram of discontinuity trace lines,identifying the largest region where random blocks appear and the combination of points,a method of matching the trace line triangles with the type of the random blocks to indentify the random blocks is put forward.The method is proved to be reasonable by engineering practice.The research provides a new approach to describe and rapidly identify the random blocks of jointed rock slope.%节理岩质边坡存在有大量由结构面和开挖坡面组合而成的随机块体.根据结构面和坡面的组合关系,将随机块体分为坡肩双面滑动、坡面双面滑动及坡面单面滑动3种类型,并运用“野外定性判断+赤平投影法”的方法综合确定边坡随机块体的类型.在详细的野外结构面采样的基础上,运用地质统计学与计算机技术随机生成三维结构面网络图.在前人关于生成结构面迹线图、搜寻封闭回路、搜索随机块体可能出现的最大区域、交点组合的基础上,提出通过对坡面迹线三角形进行随机块体类型匹配的方法,找出符合随机块体类型要求的迹线三角形,快速搜索出坡面随机块体.工程实例模拟结果亦证实了该方法的合理性,研究成果可为节理岩质边坡随机块体的形态描述、快速搜索提供一条新的思路与方法.