【摘要】 以南水北调西线工程输水隧洞为原型,针对其A围岩为砂板岩互层的特点,通过对实验室测得的岩石力学参数进行折减,利用数值模拟软件3DEC模拟了圆形无支护隧洞围岩应力应变随埋深、岩层倾角、洞径等因素改变而变化的规律,最后与地质探洞的现场观测结果进行了对比。得出结论:随岩层倾角的改变,隧洞围岩的最大位移值和塑性区范围都发生了变化,倾角为0°时,隧洞围岩自稳性最好,倾角为45°时,隧洞围岩稳定性最差;岩层倾角的变化对板岩的影响较大;随着埋深、洞径的增加,围岩的破坏形式由局部劈裂剥落向塑性挤出、膨胀坍塌转变。更多还原

【Abstract】 Taking the water conveyance tunnel of the west route of South-to-North water diversion as an example, according to the characteristics of surrounding rock with interbedded sand slate, the paper simulates the change law of stress-strain of free-standing tunnel surrounding rock following the variation of buried depth, strata inclination, tunnel diameter and others by the 3DEC numerical simulation software through reducing the laboratory parameters of rock mechanics and contrasts the results between the simulation and the field observation. The conclusions are the maximum displacement and plastic range of the tunnel surrounding rock change following the variation of strata inclination; the self-stability of surrounding rock is best while the inclination is 0° and poorest at 45°; the change of strata inclination has obvious effect on the slate; the failure mode changes from the local splitting and spalling to the plastic extrusion and expansion collapse with increasing buried depth and tunnel diameter.更多还原