摘要
为了准确分析非饱和条件下隧道掌子面稳定性,采用非饱和土体双应力状态变量抗剪强度准则研究土质和岩质隧道掌子面的稳定性问题,用极限分析上限法构建非饱和隧道掌子面的破坏模式,根据外力功率等于内能耗散率建立功率方程,推导非饱和隧道掌子面围岩压力的解析解,并通过序列二次规划算法得到隧道围岩压力或支护力的最优上限解,并分析不同参数对掌子面破坏的影响。结果表明:饱和与非饱和条件下土质掌子面围岩压力差异较大,其中土体中的基质吸力可以减小掌子面的围岩压力;当基质吸力等于进气值时,围岩压力曲线会发生明显转折;围岩内摩擦角对非饱和土质隧道掌子面的潜在破坏面位置影响较大,且内摩擦角越小,掌子面破坏范围越大。岩体饱和度Sr对岩质隧道围岩稳定性有重要影响,Sr增大时,掌子面所需要的支护力也越大。
In order to accurately solve the stability of tunnel face under unsaturated conditions,the double stress state variable shear strength criterion of unsaturated soil is used to analyze the stability of soil or rock tunnel face.The failure mode of unsaturated tunnel face is constructed by using the upper bound method of limit analysis.The power equation is established according to the external force power equal to the internal energy dissipation rate.The analytical solution of surrounding rock pressure of unsaturated tunnel face is deduced,and the optimal upper bound solution of surrounding rock pressure or support force is obtained by sequential quadratic programming algorithm,and the influence of different parameters on the failure of the tunnel face is analyzed.The conclusions are as follows.There is a large difference in pressure of the soil tunnel face for the saturated condition and unsaturated condition,in which the matrix suction in the soil can reduce the pressure of the tunnel face.When the matrix suction is equal to the air intake value,the surrounding rock pressure curve will have an obvious turning point.The internal friction angle of surrounding rock has a great influence on the location of potential failure surface of tunnel face in unsaturated soil,and the smaller the internal friction angle is,the larger the failure range of tunnel face is.The rock mass saturation Sr has an important influence on the stability of rock tunnel surrounding rock,the larger the Sr,the greater the supporting force required to support the working face.
作者
彭德劲
傅鹤林
李鲒
张凯源
安鹏涛
PENG Dejing;FU Helin;LI Jie;ZHANG Kaiyuan;AN Pengtao(China Chemical Construction Investment Group Co.,Ltd.,Beijing 100000,China;School of Civil Engineering,Central South University,Changsha,Hunan 410075,China)
出处
《水利与建筑工程学报》
2023年第5期13-20,共8页
Journal of Water Resources and Architectural Engineering
基金
国家自然科学基金资助项目(51538009)
污水管过石门湖工程施工关键技术研究(CNCECBJ-AQZB-TE-2021-03)。
