黄土盾构隧道地层特性演变规律及围岩压力计算  

Evolution law of stratum characteristics for loess shield tunnel and the calculation of surrounding rock pressure

作　　者：韩兴博[1,2] 叶飞[1,2] 陈子明 苏恩杰 欧阳奥辉 HAN Xingbo;YE Fei;CHEN Ziming;SU Enjie;OUYANG Aohui(School of Highway Engineering,Chang’an University,Xi’an 710064,China;Research Center of Highway Large Structure Engineering on Safety,Ministry of Education,Chang’an University,Xi’an 710064,China;Civil Engineering Department,University College Cork,Cork VGV5+95,Ireland)

机构地区：[1]长安大学公路学院,陕西西安710064 [2]长安大学公路大型结构安全教育部工程研究中心,陕西西安710064 [3]爱尔兰国立科克大学土木工程部,爱尔兰科克VGV5+95

出　　处：《铁道科学与工程学报》2022年第12期3715-3725,共11页Journal of Railway Science and Engineering

基　　金：国家自然科学基金资助项目(52108360);中国博士后科学基金资助项目(2020M683398)。

摘　　要：确定合理的围岩压力对隧道结构的设计及后续运营安全意义重大。受到黄土地层特殊结构性的影响,在隧道施工和浸水等扰动下,结构所承受的围岩压力将发生变化,这种变化使用常规的围岩压力计算方法难以考虑。首先,考虑盾构隧道开挖与支护的边界条件,通过复变函数理论建立了隧道围岩应力应变的理论计算方法;其后,将黄土结构性参数引入邓肯-张模型,构建了力场和浸水等作用下围岩切线模量的求解方法,实现了黄土结构性参数本构的描述;最后,结合黄土结构性本构及深埋隧道开挖支护的围岩复变函数理论解析,考虑隧道施工以及地层增湿等的扰动,构建了深埋黄土盾构隧道围岩压力的求解方法。研究发现:受到开挖及支护效应的影响,拱顶和拱底的结构性参数小于边墙部位;随含水率增加,地层的结构性显著降低,含水率25%下的结构性参数仅为5%含水率的11%;随含水率的增大,围岩切线模量逐渐降低,含水率5%~25%的降幅约为60%;随着含水率的增大,围岩压力增大,衬砌不同角度处的围岩压力增幅较为接近,含水率5%~25%的增幅在17%~19%之间。研究成果可为深埋黄土盾构隧道的围岩压力计算提供新思路。The determination of a reasonable surrounding rock pressure is of great significance to tunnel structure design and its subsequent operation safety. Affected by the special structure of loess stratum, the surrounding rock pressure bearing by the structure will change when the construction and seepage disturbance occur. And this change is difficult to be considered by the conventional calculation method of surrounding rock pressure. Firstly,the calculation method of stress and strain of tunnel surrounding rock was established through the complex variable function theory considering the boundary conditions of shield tunnel excavation and support. Secondly,the structural parameters of loess were introduced into Duncan-Chang model. Then, the solution method of tangent modulus of surrounding rock under the action of force field and humidification was constructed, and the constitutive description of loess structural parameters was realized. Finally, combined with the structural constitutive model of loess and the mechanical analysis of deep-buried tunnel considering construction and seepage effect by using complex variable function, the solution method of surrounding rock pressure of deepburied loess shield tunnel was constructed. It is found that the structural parameters of tunnel vault and bottom are smaller than those of side wall due to excavation and supporting effect. The structural behavior of loess is significantly impaired with the increase of water content, and the structural parameter at 25% water content is only 11% of that at 5%. The tangent modulus of surrounding rock decreases gradually with the increase of water content, and the decrease from 5% to 25% water content is about 60%. With the increase of water content, the surrounding rock pressure increases. The increase of surrounding rock pressure at different angles of lining is close, and the increase from 5% to 25% water content is between 17% to 19%. The research results are hoped to provide new ideas for surrounding rock pressure calculation of dee

关 键 词：盾构隧道 围岩压力 理论解析 结构性参数 

分 类 号：TU45[建筑科学—岩土工程]