内外水力交互下浅埋带压盾构隧道水土压力计算模型  

Model for calculating water and earth pressures of shallowly buried pressurized shield tunnels under external water infiltration and internal water exosmosis conditions

作　　者：谢家冲 黄昕[1,2,3] 金国龙 张子新 XIE Jiachong;HUANG Xin;JIN Guolong;ZHANG Zixin(Department of Geotechnical Engineering,Tongji University,Shanghai 200092,China;College of Civil Engineering and Architecture,Xinjiang University,Urumchi 830047,China;Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education,Tongji University,Shanghai 200092,China;China Shipbuilding NDRI Engineering Co.,Ltd.,Shanghai 200063,China;Department of Civil and Environmental Engineering,Universitat Politècnica de Catalunya(UPC),Barcelona 08034,Spain)

机构地区：[1]同济大学土木工程学院地下建筑与工程系,上海200092 [2]新疆大学建筑工程学院,新疆乌鲁木齐830047 [3]同济大学岩土及地下工程教育部重点实验室,上海200092 [4]中船第九设计研究院工程有限公司,上海200063 [5]加泰罗尼亚理工大学土木与环境工程学院,巴塞罗那08034

出　　处：《岩土工程学报》2024年第8期1685-1694,共10页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(52278407);上海市科技创新行动计划项目(21DZ1201103);国家留学基金委项目(202306260053)。

摘　　要：针对浅埋有压盾构隧道内外水力交互渗流下引起的松动水土压力变化,基于修正镜像法获得了考虑内水压的地层渗流场分布与水力梯度。随后基于考虑松动区内部应力分布的修正Terzaghi公式给出了考虑隧道内水压下的松动区任意位置的水土压力解,并与数值模拟结果进行了对比验证。主要结论如下:采用圆弧拱和抛物线拱的主应力轨迹线能够有效描述隧顶松动区应力分布情况;当地层渗透系数与衬砌渗透系数比值小于1000时,内压水头大小对水土压力的影响显著;内压水头的增加将减小松动区有效应力,引起上覆土体卸载,同时引起隧顶松动区总应力增大,表明该范围内孔隙水压的增长对水土压力的变化占据主导作用;5参数正交分析结果的线性回归分析结果表明隧道埋深和半径对土压力有显著的正向影响,土体摩擦角和黏聚力均表现为负向影响。在相对低渗透地层条件下,内压水头对隧顶有效应力和总应力分别表现为显著的负向和正向影响。Focusing on the variation of relaxed water and earth pressures of shallowly shield tunnels under external water infiltration and internal water exosmosis conditions,the seepage field and hydraulic gradient considering internal water pressure are firstly,derived based on the modified image method.Then,the solutions for the water and earth pressures in arbitrary locations within the relaxed zone are obtained based on the modified Terzaghi’s formula considering the horizontal distribution of stress.The effectiveness of the computational model is verified by comparing with the numerical results.It is shown that the principal stress path in either an arc or a parabola form can effectively capture the stress distribution within the relaxed zone over the tunnel crown.When the ratio of permeability of strata to that of linings is below 1000,the internal water pressure head has significant effects on the water and earth pressures.The increase of internal water pressure head will cause the reduction on the effective stress in the relaxed zone,which induces the unloading of soils.Moreover,it will also result in the increase of the total pressures at the tunnel crown of the relaxed zone,implying that the growth in pore pressure dominates the variation of the water and earth pressures.The linear regression of five-parameter orthogonal analysis suggests that the buried depth and tunnel radius have significant positive impacts on the earth pressures,while the influences of friction angle and cohesion are negative.Under the scenarios of relatively low-permeable strata,the influences of internal water head on the total and effective earth pressures at the tunnel crown are significantly negative and positive,respectively.

关 键 词：带压盾构隧道 衬砌渗漏 内水外渗 松动土压力 土拱 镜像法 

分 类 号：TU432[建筑科学—岩土工程]