大跨径隧道围岩的快速分级与稳定性图解分析

摘要

A case study of rock mass rapid and dynamic of large-span freeway tunnel using BQ and CSIR methods of surrounding rock quality classification on detailed geological surveying.The results show that the surrounding rock quality is between class Ⅲ and Ⅳ.The application of stereographic projection and solid scale projection on the tunnel surrounding rock(s stability indicates that instability structure of vault is oblique tetrahedron and volumetric of possible collapse is 43 m3 .The fact has proved applying the method of geology analysis in tunnel construction has an good effect on dynamic classification and evauation of rock mass quanlity.%以某高速公路大跨径隧道为研究对象，在详细地质调查基础上，采用BQ围岩分级和CSIR岩体质量分类方法，对该隧道一段围岩进行快速动态分级，结果表明围岩质量应介于Ⅲ级和Ⅳ级之间。采用赤平极射投影和实体比例投影法对本段隧道稳定性进行快速图解分析评价，结果显示，拱顶不稳定结构体为斜四面椎体，可能塌落的岩体体积最大为44．4 m3。实践证明在隧道施工中采用地质分析法对围岩质量进行动态分级和评价简便快捷，收效好。