摘要
围岩质量分类是隧道及地下工程领域重要的技术工作之一。限于经验,目前常用的围岩质量分类方法主要适用于中低应力、低应力环境,而在高地应力地区的适宜性较差。文章结合某水电工程实例,先后采用BQ分类、HC分类、RMR分类以及Q系统分类方法,分别就4种方法分类结果的相关性、吻合率和一致性等方面开展了系列对比研究和初步的成因分析。发现无论是上述4种方法各自的分类依据和指标,还是各指标权重的大小均有较大差异。故针对高地应力环境,以及研究区高地应力条件下的岩爆问题,分别对现行Q系统分类、HC分类和RMR分类方法逐一进行了修正。如Q系统重点修正了地应力折减系数、节理粗糙度系数Jr和节理风化蚀变系数Ja;HC分类提出了考虑高地应力和岩爆烈度的地应力折减系数,而取消了强度应力比S;RMR方法主要修正了R6,并增加了地应力折减系数K等。修正后的Q、HC、RMR方法所得结果更接近实际情况。最后,基于概率统计方法,建立了采用多种方法的围岩综合分类方案。
Surrounding rock quality classification is one of the professional key works in tunneling and underground engineering. So far, the popular methods of surrounding rock quality classification might suitable for the mid-lower or lower primary stress, but nearly useless in high primary stress condition, because of cases shortage. Based on an hydraulic power engineering in high primary stress case, this paper use classification methods BQ, HC, RMR and Q system in turn to determine the quality grade of surrounding rock. The coherence and difference of above four classification result was deeply studied by contrasting and reason analyzing. And an important fact was found that classification rule and its index or weight for every index all had notable difference in above four classification methods. So, the classification methods Q cording to high primary stress environment and roughness coefficient Jr and joint weathering and system, HC, RMR at present had been modified one by one acrock-burst. For Q system, primary stress reduction factor, joint erode coefficient Ja had been mainly modified. For HC classification method, considering the influence of high primary stress and rock-burst, propose primary stress reduction factor K, cancel the index of ratio of strength and stress S. For RMR classification method, the index of R6 was mainly modified, at the same time, primary stress reduction coefficient was added. The classification result was much more accordant to the matter of fact after being modified. In the end, based on probability and statistical theory, general classification scheme was put forward.
出处
《地球科学进展》
CAS
CSCD
北大核心
2008年第5期482-488,共7页
Advances in Earth Science
基金
四川省杰出青年学科带头人培养基金项目“开发边坡卸荷机理”(编号:04-zq026-016)资助
关键词
高地应力
围岩质量分类
岩爆
High primary stress
Surrounding rock quality classification
Rock-burst.
