FRACTURE MODEL OF JOINTED ROCK MASS SUBJECTED TO SEISMIC LOADING
地震载荷作用下的节理岩体破裂模型

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.