基于倾斜滑裂面假设的浅埋盾构隧道松动土压力研究  

Research on Loosening Earth Pressure of Shallow Buried Shield Tunnel Based on the Assumption of Inclined Sliding Surface

作　　者：梁连 方焘[1,2] 方立建 LIANG Lian;FANG Tao;FANG Lijian(School of Civil Engineering and Architecture,East China Jiaotong University,Nanchang Jiangxi 330013,China;College of Civil Engineering,Fuzhou University,Fuzhou Fujian 350108,China)

机构地区：[1]华东交通大学土木建筑学院,江西南昌330013 [2]福州大学土木工程学院,福建福州350108

出　　处：《中国铁道科学》2024年第3期97-106,共10页China Railway Science

基　　金：国家自然科学基金资助项目(52168048)。

摘　　要：随着地铁建设的快速发展,隧道上方松动土压力的计算成了隧道工程领域的研究热点,而隧道松动区的确定对松动土压力的计算至关重要。为简便而准确地确定松动区的范围,首先假设松动区的边界为倾斜直线,然后基于Mohr-Coulomb破坏准则并考虑隧道尺寸、埋深等因素的影响推导滑裂角计算式,进而确定隧道周围地层的松动区范围。最后结合松动区土体主应力轴旋转理论以及倾斜滑裂面的假设,推导出滑裂面上的侧压力系数以及隧道松动土压力的计算式。结果表明:滑裂角随土体内摩擦角的增大而增大,随隧道埋深比的增大先减小然后趋于稳定;大主应力轨迹线为圆弧时计算更为简便、更易推广,可采用圆弧形大主应力轨迹的假设计算隧道松动土压力;松动土压力计算式所得结果和实际的试验结果吻合较好,因此该计算式可应用于砂土地质条件下浅埋盾构隧道上方的松动土压力计算。With the rapid development of metro construction,the calculation of loosening earth pressure acting on tunnels has become a research hotspot in the field of tunnel engineering.Accurate prediction of the loosening zone around tunnels is crucial for determining the loosening earth pressure.To simplify and precisely estimate the extent of the loosening zone around tunnels,its boundaries were first postulate as two inclined straight lines.Then,a formula for the sliding angle was derived considering tunnel size,buried depth of the tunnel,and other conditions based on the Mohr-Coulomb failure criterion,and thus the loosening zone of strata around the tunnel could be determined.Finally,the lateral pressure coefficient on the sliding surface and the formula for calculating the loosening earth pressure above tunnel were deduced by integrating the theory of principal stress axis rotation in the loosening zone soil mass with the assumption of an inclined sliding surface.The study shows that the sliding angle increases with the increase of the internal friction angle of soil,and initially decreases with the increase in tunnel burial depth ratio,subsequently stabilizing.When the trajectory line of the major principal stress is assumed to be circular,the calculation is more straightforward and conducive to wider application.The results obtained from the analytic solution presented in this paper align well with the actual test results,indicating its applicability for the calculation of loosening earth pressure above the shield tunnel in sandy strata.

关 键 词：隧道工程 松动区 土压力 土拱效应 滑裂面 数值模拟 

分 类 号：U452[建筑科学—桥梁与隧道工程]