【摘要】 隧道周边围岩结构复杂,如节理、地裂缝等,势必会对隧道的安全造成一定的负面影响。利用Abaqus软件,对双轴压缩情况下,隧道穿过不同位置的地裂缝的情况进行了数值模拟,分析研究了裂缝倾角α、裂缝长度l以及隧道侧压力系数λ对两个裂纹尖端应力强度因子及隧道稳定性的影响。结果表明:(1)裂纹倾角、裂缝长度、侧压力系数对裂尖应力强度因子的影响明显,隧道周边径向双裂纹大大削弱了隧道的强度及稳定性;(2)由于隧道构形的影响,上下两裂尖的应力强度因子分别在倾角为45°和52°达到最大值,需要特别注意在裂纹倾角45°~52°附近隧道的安全性;(3)侧压力系数在0.8~1.2范围内有削弱裂纹尖端应力集中的作用,有利于隧道的安全性;(4)当裂缝长度与隧道宽度比例超过5倍时,应主要考虑裂缝对隧道安全性的影响。更多还原

【Abstract】 The complex rock mass structures around tunnel,such as jointing,ground fissures,will have negative influence of tunnel safety. By using Abaqus software,the tunnel under biaxial compression which goes through ground fissure is simulated. The crack inclination α,crack length l and lateral pressure coefficient λ are analyzed for the influence of SIF and the stability of tunnel. The results show that:( 1) crack inclination,crack length and lateral pressure coefficient have a great influence on SIF,and reduce the strength and stability of tunnel;( 2) because of the shape of tunnel,the SIFs for upper and down crack tips reach the maximum when α is 45° and 52° respectively,which means one should pay more attention to tunnel safety when α is between 45° and 52° approximately.( 3) the value of λ between 0. 8 and 1. 2 has a good effect on weakening stress concentration for crack tips,which is good for tunnel safety.( 4) the crack effects on tunnel are the main consideration when the ratio of crack length to tunnel width is more than 5.更多还原