【摘要】 为得到地震下无衬砌圆形黄土隧洞的围岩稳定安全系数,应用抗剪强度折减法,建立静力与动力分析模型,采用ANSYS软件分别对圆形无衬砌黄土隧洞进行重力和地震下的动力响应分析,得到地震下无衬砌圆形黄土隧洞的剪切破坏规律,讨论了隧洞直径、覆土厚度以及地震烈度对无衬砌圆形黄土隧洞围岩抗剪强度安全系数的影响.结果表明,在重力和地震作用下,对介于1.15~2.00的无衬砌圆形黄土隧洞的抗剪强度安全系数只能满足初次衬砌要求,不能满足使用阶段要求.为保证结构的安全可靠,建议开挖之后尽快进行二次衬砌.更多还原

【Abstract】 In order to obtain the stability safety factors of soil surrounding unlined circular loess cave under earthquake action,using shear strength reduction method,taking the static and dynamic analysis model,and applying the ANSYS software,the static stability analysis and the earthquake dynamic response analysis about the soil surrounding the unlined circular loess cave were performed.So the shear failure laws of the surrounding soil under earthquake action are obtained.The effects of the cave diameter and coverage soil thickness of cave and seismic intensity on the shear strength safety factor were discussed.The results show that under the gravity and seismic action,the shear strength safety factors of unlined circular caves are generally greater than 1.15 and smaller than 2.00.Therefore the requirements of initial lining can be met,but the requirements of the using phase can not.It is suggested that,in order to ensure the structure safety,the second lining after excavation should be done as soon as possible.更多还原