摘要
从认识论的角度提出数值仿真技术服务于地下工程实践的PFP分析方法,并随拉西瓦水电站地下厂房工程开挖进度分3个阶段对洞群围岩稳定性进行系统地分析和预测。研究成果表明:在高地应力硬岩洞室群开挖过程中,不同部位围岩位移具有明显的空间差异性和时间渐变性;岩体中应力表现出一定的波动性、转移性;多洞室交叉使得围岩松弛区域具有一定的特殊性;围岩破损模式和深度也具有区域差异性等。其成果为洞室开挖与围岩支护改进提供了科学依据,也被实际洞室开挖过程揭示的变形规律和围岩开裂、掉块等破坏模式所证实。这些高地应力下硬岩力学行为规律对其他类似地下工程围岩稳定性研究也具有较好的借鉴意义。
The Laxiwa Hydropower Station, constructed in high mountain with steep slope and deep gorge, is the largest hydropower station in Yellow River area. Its underground powerhouse consists mainly of main powerhouse, auxiliary powerhouse, main transformation cavern, pressure adjustment well, caudal shiplock cavern, and caudal water tunnel, which has vertical depth of 282 ～ 429m. The granite is weakly weathered in the area of the underground powerhouse, with grey-grey white, middle coarse size, block structure and mineral component of mainly feldspar. The underground powerhouse cavern group is in high stress field with the maximal principal stress of -22 - -29 MPa. In order to evaluate the stability of hard rock cavern group under high geostress, a new method, named PFP（preparation, feedback and prediction）, is presented. It is carried out by three phases along with the progress of the excavation of the underground caverns in Laxiwa Hydropower Station. The results show that the deformations of rock wall are different in different spaces and increase with the step of excavation; the sequential tunnelling layer makes the stress undulation and transfer; the stress looseness zone is greatly different from the normal tunnel because of cross-caverns; the EDZ has different failure models and depths in different positions, and so on. The study proposes scientific suggestion for excavation and supporting of the caverns, which is also identified by the mechanical behaviour of rock in practice. The method and conclusions can offer a useful reference for other similar underground projects.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2008年第A02期3768-3777,共10页
Chinese Journal of Rock Mechanics and Engineering
基金
国家科技支撑计划项目(2006BAB04A06)
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开放基金(Z000701)
关键词
岩石力学
高地应力
地下洞室群
反馈分析
围岩稳定性
拉西瓦水电站
rock mechanics
high geostress
underground caverns
feedback analysis
rock mass stability
Laxiwa Hydropower Station
作者简介
江权（1978-），男，2001年毕业于中国地质大学隧道与地下工程专业，现为博士研究生，主要从事地下工程数值模拟、稳定性分析及工程地质灾害治理方面的研究工作。E-mail：jiangquan@163．com
