遍布节理对地下洞室群围岩稳定性的影响研究  

Effect of ubiquitous joints on the stability of surrounding rock mass of multiple underground caverns

作　　者：冷先伦[1] 盛谦[1] 朱泽奇[1] 张勇慧[1] 

机构地区：[1]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：《土木工程学报》2009年第9期96-103,共8页China Civil Engineering Journal

基　　金：国家自然科学基金重大研究计划重点支持项目(90715042);国家科技支撑计划项目(2006BAB04A06);院方向性项目(KZCX2-YW-109-3)

摘　　要：因地质条件的复杂性,导致节理、断层、裂隙等弱面较为发育,致使在对大型地下洞室群围岩稳定性研究中很难全面考虑各弱面对稳定性的影响,因此我们通过引入遍布节理模型,同时考虑岩块和节理属性,使研究更加符合岩体状态及工程实际。介绍可考虑岩体中节理弱面的遍布节理弱面模型及其在有限差分程序中的实现,选取佛子岭抽水蓄能水电站地下厂房洞室群作为工程实例,对比分析洞室围岩在莫尔-库伦模型和遍布节理模型两种条件下的位移、应力状态和塑性区发展情况。在引入遍布节理模型后,洞室壁水平位移值增长显著,主应力值有一定程度增加,而围岩顶拱和底板变化不明显,只略有加大,在洞室交接处,应力集中现象较明显。运用正交设计方法,选取六种不同走向和倾向的遍布节理弱面,研究遍布节理弱面的走向和倾向对围岩变形的影响。研究结果表明,遍布节理弱面对地下洞室群围岩稳定性有较大影响,当其方向与断层弱面方向垂直且与洞室群成斜交时,影响最大。Complexity of geological conditions leads to development of weak planes including joints, fractures, and faults, and makes it difficult to consider the effects of all these types of weak planes. The ubiquitous-joint model considering the effect of joint weak planes in rock mass in FLAC^3D is introduced. The fuziling pumped storage hydropower station is taken as an example for numerical analysis, and the displacement, stress and plastic yielding region of the surrounding rock mass of the underground cavern group are analyzed by applying the Mohr-Coulomb model and the ubiquitous-joint model, respectively, in FLAC^3d. For the ubiquitous-joint model, the horizontal displacement of the cavern wall and the principal stress are greater than those by Mohr-Coulomb model, but the increases are not evident in the crown and floor of underground cavern. Moreover, the stress concentration can be easily observed in the intermediate regions between the caverns. Six types of ubiquitous-joint weak planes with different strikes and dips are chosen by uniform design to study the effects of strikes and dips on the deformation of the surrounding rock mass. The results show that ubiquitous-joint weak plane significantly affects the deformation of the surrounding rock mass, and the effect is maximal when the ubiquitous-joint weak planes are perpendicular to the fault plane and oblique to the cavern group.

关 键 词：遍布节理模型 地下洞室群 围岩稳定 正交设计 FLAC^3D 

分 类 号：TU473.5[建筑科学—结构工程]