地下水对节理岩体隧洞围岩稳定性的影响

Effect of Groundwater on the Surrounding Rock Stability of Jointed Rock Mass Tunnel

采用离散网络渗流模型模拟节理岩体中的渗流,分析渗流对节理地下洞室稳定性的影响。通过对洞室开挖后常规静力荷载、常规静力荷载与渗透压力耦合作用以及常规静力荷载作用下考虑地下水对洞室围岩的软化作用3种工况进行模拟,得出洞室在3种工况下的应力和位移变化情况。结果表明:考虑地下水与否,不受其他外加荷载作用时,节理岩体地下洞室的围岩都不会遭到破坏;有高水头地下水作用时,渗透压力对洞室围岩的影响要比地下水对洞室围岩的软化作用对洞室围岩的影响大得多;渗透压力对地下洞室围岩的影响主要集中在洞顶部位,洞室侧壁围岩受地下水的影响较小。

Adopting discrete network seepage model to simulate the seepage in jointed rock mass,this paper analyzed the influence of seepage to the stability of jointed underground cavern.Through the simulations under three working conditions of conventional static load,coupling action of conventional static load and seepage force,considering the mollification of groundwater to cavern surrounding rock under conventional static load after excavation,the variations of stress and displacement under the three working conditions were obtained.The results show that： whatever the groundwater is considered or not,the surrounding rock of jointed rock mass underground cavern will not be damaged if there is no additional load;having high head groundwater action,the influence of osmotic pressure to cavern surrounding rock is much bigger than the mollification effect of groundwater;the influence of osmotic pressure to the surrounding rock of underground cavern mainly concentrates on the top position of the cavern,while the influence of groundwater to the lateral surrounding rock of the cavern is smaller.