地震载荷作用下的节理岩体破裂模型

考虑了地震水平加速度的作用,建立了裂隙岩体的破裂模型,分析了在水平加速度作用下节理组的倾角、节理长度及间距对岩体破裂的影响。分析表明,节理的倾角越大,岩体越容易破坏;节理组的倾角增大过程中,岩体节理的破坏模式逐步由以剪切滑移破坏为主转为以张拉破坏模式为主;当节理的间距与长度的比值在一定的范围内时,该比值越大,岩体越容易破坏,同时,节理的长度越大,岩体越容易破裂。该模型对于地震载荷作用下的岩体安全性分析具有重要的意义。

FRACTURE MODEL OF JOINTED ROCK MASS SUBJECTED TO SEISMIC LOADING

A fracture model of jointed rock mass is established considering the effect of horizontal seismic acceleration. Based on the proposed model,the relationship between the stress intensity factor,and length,spacing and dip of joints is discussed. The analytical results show that the stress intensity factor is significantly dependent on the joint dip when subjected to the horizontal acceleration. When the joint dip is increasing,the rock mass becomes more likely to be fractured. Moreover,with the increasing of the joint dip,the dominant fracture mechanism will change from the sliding type to the tensile type. The effect of the joint length on the fracture is also significant. The bigger the joint length is,the more likely the rock mass is to be fractured if the ratio of the joint spacing to the joint length is moderate. If the ratio of the joint spacing to the joint length is too big or too small,the proposed model will be invalid. The proposed model is practically valuable for the safety analysis of rock mass subjected to seismic loading.