作　　者： ; ; ; (方建勤）;

机构地区： 中南大学信息物理工程学院

出　　处： 《岩土力学》 2012年第1期268-272,279,共6页

摘　　要： 以广梧高速公路牛车顶隧道为工程背景,探讨岩体流变情况下隧道二衬支护时机确定的理论和数值计算方法。对比理论方法预测拱顶下沉时程曲线与现场实测结果,建立数值计算模型,分析隧道围岩应力释放系数对围岩稳定性的影响表明,理论方法预测拱顶下沉时程曲线与现场实测表现出相同的发展规律,并且二者得到的二衬支护时间基本相同,验证了理论方法的正确性。围岩应力随着掌子面推进而不断释放,III级围岩应力释放比较缓慢,空间效应比较明显;当开挖释放应力系数大于或等于60%时,整个围岩的松动区都大于锚喷加固范围,最终确定出二衬的合理支护时机,为工程实践提供参考。 The Niucheding tunnel in Guangzhou-Wuzhou Expressway is taken as the engineering background, the analytical and numerical calculation method for the second lining time of tunnel under the conditions of rock mass rheological characteristic are analyzed. The disciplines of the arch settlement obtained from the proposed method are compared with that from the monitoring data; then the numerical calculation model is founded to analyze the influence of stress releasing coefficient on the stability of surrounding rock mass of tunnel. The analysis results show that, the disciplines of the arch settlement obtained from the proposed method are the same with that from the monitoring data, which validates the correctness of the proposed method. The stress of surrounding rock mass is released gradually with the tunnel face moves on; and the releasing rate is slow in the Ⅲ degree of rock mass, which shows obvious spatial effect. According to the numerical calculation results, if the stress releasing coefficient is larger or equal to 60%, the whole area of the disturbed zone is larger than the area the bolt can reinforce. Finally, the appropriate second lining time is obtained so as to give some guidance for the real practice.

关 键 词： 隧道 二衬支护时机 流变 监测 数值计算 应力释放系数

领　　域： [建筑科学] [建筑科学]