基于岩石强度应力比的35~50 m跨度硬岩洞室围岩稳定性评价  

Rock strength-stress ratio-based evaluation analysis on surrounding rock stability of hard rock cavern with span of 35~50 m

作　　者：汤艳春[1] 朱泽民 张传庆[2] 郑玉照 TANG Yanchun;ZHU Zemin;ZHANG Chuanqing;ZHENG Yuzhao(Key Laboratory of Geological Hazards on Three Gorges Reservoir Area of Ministry of Education,China Three Gorges University,Yichang 443002,Hubei,China;State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan 430071,Hubei,China)

机构地区：[1]三峡库区地质灾害教育部重点实验室(三峡大学),湖北宜昌443002 [2]中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室,湖北武汉430071

出　　处：《水利水电技术（中英文）》2022年第4期128-137,共10页Water Resources and Hydropower Engineering

基　　金：国家自然科学基金项目(51779129)。

摘　　要：为了研究35~50 m跨度的大型硬岩地下洞室围岩稳定性,分析了34例18~35 m跨度硬岩洞室的工程资料,就不同岩石强度应力比对不同跨度、不同高度下35~50 m跨度硬岩洞室围岩稳定性的影响进行数值模拟。结果表明:(1)岩石强度应力比对围岩稳定性影响的敏感度曲线可分为基本不变、缓变、陡变三个阶段,基本不变与缓变阶段的界限值为7.4~7.8,缓变与陡变阶段的界限值为4.3~4.8,随着洞室尺寸的增大,敏感度曲线界限值有所增加;(2)34例大跨度硬岩洞室的岩石强度应力比均处于基本不变或缓变阶段,敏感度曲线的三阶段划分与工程实践吻合度较高,能较好地评价硬岩洞室设计的可行性;(3)工程类比下硬岩洞室(跨度大于35 m)在岩石强度应力比大于5.0~5.7时围岩变形和塑性区深度与金沙江某硬岩洞室基本一致,具有较好的围岩稳定性。相关研究思路和成果可为大跨度硬岩洞室设计与施工提供参考。In order to study the surrounding rock stability of large-sized underground hard rock cavern with the span of 35~50 m,the engineering data of 34 cases of hard rock caverns are analyzed herein,in which the influences from different rock strength-stress ratios on the stabilities of the hard rock caverns with the spans of 35~50 m under the conditions of different spans and heights are numerically simulated.The results show that(1)the sensitivity curve of the influence from the rock strength-stress ratio on the stability of the surrounding rock can be divided into three phases,i.e.basically unchanged,slowly changed and sharply changed,while the boundary value between the basically unchanged phase and the slowly changed phase is 7.4~7.8 and the boundary value between the slowly changed phase and the sharply changed phase is 4.3~4.8.The boundary value of the sensitivity curve is to be increased to some extent along with the increase of the cavern size;(2)the rock strength-stress ratios of the 34 cases of large-span hard rock caverns are all in the basically changed phase and slowly changed phase,while the division of the three phases of the sensitivity curve is highly coincided with that from the engineering practice,and then can be used to evaluate the feasibility of the design of hard rock cavern;(3)under the relevant engineering analogy,when the rock strength-stress ratio of the hard rock cavern(with the span over 35m)is larger than 5.0~5.7,the deformation and the depth of the plastic zone of the surrounding rock are basically consistent with those of a large-sized hard rock caver at Jinshajiang River and then has better stability of the surrounding rock.The relevant study ideas and results can provide better references for the design and construction of large-sized hard rock cavern.

关 键 词：大跨度硬岩洞室 强度应力比 围岩稳定性 数值模拟 

分 类 号：TU457[建筑科学—岩土工程]