摘要
深部资源开发中地下洞室围岩稳定控制必须面对峰后碎裂岩体的变形和破坏问题,目前深部多裂隙岩体开挖强卸荷引起的围岩变形破坏规律尚不清楚,常导致大体积塌方、大变形等重大工程事故。采用大尺度三维模型相似试验系统,分析具有不同倾角的多层节理的岩体在高地应力下开挖变形破坏规律。试验结果表明:裂隙倾角较小时,隧道上、下侧围岩主要发生大变形,左、右侧围岩呈现分层破裂现象,随着裂隙倾角增大,破裂区从洞室左、右两侧逐渐扩展到洞室全周,顶部岩体越容易发生大体积滑塌;隧道围岩由内向外应力和位移值呈波动状分布;洞周塑性区范围随裂隙倾角增大而增大,裂隙倾角越大,洞周塑性区越容易与洞室上、下侧裂隙面连通。该研究为保障深部工程的安全修建与运营提供了试验基础。
Surrounding rock stability of underground caverns in the deep resources development are facing deformation and failure problems of post-peak fractured rock. The deformation and failure mechanisms of the deep fractured surrounding rock in strong unloading excavation are unclear, which normally leads to large volume collapse, large deformation and other major engineering accidents. In the current study, a large scale three-dimensional experimental model testing is conducted to investigate the characteristics of deformation and failure of deep rock mass with multi-cleftiness of different angles under the excavation condition at high in-situ stress. When the crack angle is small, the surrounding rock on upper and lower sides mainly presents large deformation phenomenon, and the rock on the left and right sides shows layered fracture phenomenon. With the increase of crack angle, the rupture zone from the left and right sides of tunnel gradually extends to the whole tunnel, and the top rocks become more prone to collapse. The displacement and stress of surrounding rock show the fluctuation from inside to outside. The plastic zone around the tunnel increases with the increase of crack angle. The larger the crack angle, the more the plastic zone around the tunnel is easily connected with the prefabricated crack at the top and bottom of the tunnel. The research provides some experimental data for ensuring the safety of construction and operation of deep underground engineering.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2016年第10期2899-2908,共10页
Rock and Soil Mechanics
基金
国家重点基础研究发展计划(2010CB732002)
国家自然科学基金(No.51179098
No.51379113)
高等学校博士学科点专项科研基金(No.20120131110031)
教育部新世纪优秀人才支持计划(No.NCET-12-2009)~~
关键词
高地应力
多层节理
分层破裂
模型试验
high in-situ stress
multi-cleftiness
layered fracture
model test
