【摘要】 为了研究底板保护层的实际效果,采用数值计算软件FLAC3D对预留和取消底板保护层两种方案进行了对比分析,结果表明:取消底板保护层时,底板的位移和塑性区深度、拱顶和边墙的变形都小于预留底板保护层的开挖方案;对改变洞室第三层和第四层开挖深度的不同方案进行了对比分析,结果表明:第四层的深度越大,开挖完成后底板的位移和洞室边墙的变形越小。通过对比分析可知,取消底板保护层的方案较好,并且底板上部预留的开挖深度越大越好。更多还原

【Abstract】 For the purpose of studying the actual effect of the base protective layer,a series of calculations and analysis are carried out by the numerical calculation software FLAC3 D.Firstly,the two programs of reservation and cancellation the base protective layer are calculated and compared.The result shows that the displacement and the depth of plastic zone of the bottom,the deformation of the dome and sidewall are less than the excavation scheme of reserve the base protective layer when the base protection layer is canceled.Then,different scenarios are compared through changing the excavation depth in the lower of the cavern.The result shows that the greater the depths are reserved after once excavation of the lower,the smaller the displacement and the deformation of the cavern sidewall.Through the comparison and analysis the following conclusion is got that the program of cancellation the base protective layer is better,and the reserved excavation depth on the bottom is better.更多还原