摘要
锦屏I级水电站地下厂房洞室群开挖支护设计与施工控制以及整体稳定性等问题十分突出,施工期已经明显呈现出高应力、低强度应力比条件下围岩的卸荷变形与破坏特征。根据锦屏I级地下厂房层状岩体力学特性,采用考虑卸荷演化的层状岩体本构模型及其数值模拟方法,反演获得初始地应力场以及层状岩体力学参数。在此基础上,对锦屏Ⅰ级地下厂房洞室群进行三维数值模拟分析,获得一些对高应力下锦屏Ⅰ级水电站大型地下洞室群施工期围岩稳定与支护安全等方面的认识,提出洞室群围岩应力释放调控、松弛区承载力调控以及变形开裂调控等适时工程调控措施与建议。研究结果表明,洞室群整体开挖完成后的现场监测结果和围岩稳定现状等证实了所提出的认识和调控措施的合理性,表明层状岩体本构模型及其数值模拟分析方法能够较好地反映高应力下层状岩体中大型地下洞室群施工期的工作性状。
The problems including support design, construction control and overall stability of surrounding rock are very serious in the underground caverns of Jinping I hydropower station. The unloading deformation and failure characteristics of surrounding rock under the conditions of high stress and low strength stress ratio have been clearly shown during the excavation. According to the mechanical characteristics of layered rock, the initial stress field and mecbanical parameters of layered rock are obtained by inversion analysis considering the unloading mechanical evolution of layered rock and its numerical simulation method. Based on these, the three- dimensional numerical simulation for the underground caverns ofJinping I hydropower station is carried out and some opinions of surrounding rock stability and support safety under high stress are obtained. The right engineering control suggestions including stress release control, capacity control of damaged zones and deformationcracking control, and so on, are put forward. The results show that the rationality of raised opinions and proposed control measures are confirmed by in-situ monitoring results of underground caverns and stability status of surrounding rock. It is shown that the proposed layered rock constitutive model and its numerical simulation method can reflect favorably the working behaviors of layered rock mass in the construction of large underground caverns in condition of high stress.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2011年第11期2203-2216,共14页
Chinese Journal of Rock Mechanics and Engineering
基金
国家重点基础研究发展计划(973)项目(2011CB710603)
国家自然科学基金资助项目(50909007)
水利部公益性行业科研专项项目(201001009)
关键词
岩石力学
锦屏Ⅰ级水电站
地下洞室群
高地应力
低强度应力比
层状岩体本构模型
卸荷演化
工程调控
rock mechanics
Jinping I hydropower station： underground caverns
high geostress
low strengthstress ratio
layered rock mass constitutive model unloading evolution
engineering control measures
