摘要
隧道施工造成的超欠挖会改变围岩的应力状态,甚至影响围岩的稳定性。文章依据隧道超欠挖断面轮廓和喷射混凝土层覆盖厚度,将超欠挖下的围岩边界分为三类,即平行覆盖、底部覆盖和完全覆盖;基于弹性厚壁圆筒理论,推导了等效厚壁圆筒层的刚度和最大支护压力等参数;再依据锚喷支护并联体系,建立了隧道超欠挖下锚喷支护复合结构的刚度和最大支护力的计算公式。并以莲花山2号隧道为工程实例,利用收敛-约束原理进行了稳定性分析,结果表明,隧道超欠挖下的围岩稳定性分析更符合实际,验证了该方法的可行性。
The overbreak and underbreak caused by tunnel construction will change the stress state of surrounding rocks and even affect the stability of surrounding rocks.The boundary of surrounding rocks is divided into three categories,namely parallel overlay,bottom overlay and complete overlay according to the section contours of tunnel with overbreak and underbreak and the thickness of shotcrete layer;based on the elastic thick-wall cylinder theory,the stiffness of equivalent thick-wall cylinder and the maximum support pressure are deduced;the calculation formula of stiffness and the maximum support pressure of the composite support structure with shotcrete and anchor bolts are established on the basis of parallel system of anchor bolts and shotcrete;stability of the Lianhuashan No.2 tunnel is analyzed by convergence-confinement theory,and the results show the stability analysis of surrounding rocks considering the effect of overbreak and underbreak is more in accordance with the actual situation,verifying this analysis method.
作者
刘明才
LIU Mingcai(China Railway 14th Bureau Group 2^nd Engineering Co.,Ltd.,Taian 271000)
出处
《现代隧道技术》
EI
CSCD
北大核心
2019年第6期78-84,共7页
Modern Tunnelling Technology
关键词
隧道超欠挖
厚壁圆筒理论
锚喷支护
喷层厚度
并联体系
收敛-约束法
围岩稳定性
Tunnel overbreak and underbreak
Theory of thick-wall cylinder
Support with anchor bolt and shot-crete
Thickness of shotcrete spraying
Parallel system
Convergence-confinement method
