【摘要】 以埋深为6～13m 的某浅埋人防隧洞为研究对象,应用快速拉格朗日有限差分程序(FLAC)对不同跨距、不同岩性的隧洞顶板在不同荷载作用下的破坏规律及破坏机制进行数值模拟研究,确定了隧洞围岩破坏域,并对拱顶敏感块体进行跟踪分析。研究结果表明:隧洞跨距为2m 且顶板岩层为泥岩时,隧洞顶板有一定的承载能力,当上部荷载达到0.7MPa 时隧洞才破坏;隧洞跨距为3m 且顶板岩层为泥岩时,当上部荷载达到0.33MPa 时,隧洞就已经破坏;隧洞项板为卵石层时,即使上部不施加荷载,在自重应力的作用下,隧洞亦破坏。该研究对类似的浅埋地下工程围岩稳定性分析具有实际意义。更多还原

【Abstract】 Taking one shallow-buried air-raid shelter of which buried-depth is about 6m to 13 m for example,this paper simulates the failure laws and the failure mechanism of the tunnel-roof which has different spans and rock characters and different loads using the FLAC;determines the failure fields of the roof rock masses of the tunnel;and then studies the sensitive rock mass of the arch.The results show that the tunnel roof has some bearing capacity when the span is 2 m and the roof-rock is mudstone;and the tunnel collapsed until the load reached 0.7 MPa;but if the span is 3 m,the tunnel collapsed when the load reached 0.33 MPa.If the tunnel roof is pebble stratum,the tunnel collapsed under the overburden pressure even it has no loading.This study has practical meanings to the similar study about the stability of the surrounding rock masses of shallow-buried underground engineering.更多还原