隧道下穿施工引起既有隧道及地层变形预测的改进随机介质理论模型  

Improved stochastic medium theoretical model for predicting deformation of existing tunnels and strata caused by excavation of new undercrossing tunnels

作　　者：徐强 朱永全 雷升祥[1,3] 刘勇 赵伟 方智淳 王聪 徐硕 XU Qiang;ZHU Yongquan;LEI Shengxiang;LIU Yong;ZHAO Wei;FANG Zhichun;WANG Cong;XU Shuo(School of Civil Engineering,Shijiazhuang Tiedao University,Shijiazhuang 050043,China;State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures,Shijiazhuang Tiedao University,Shijiazhuang 050043,China;China Railway Construction Corporation Limited,Beijing 100855,China;China Railway 18th Bureau Group Co.,Ltd.,Tianjin 300222,China)

机构地区：[1]石家庄铁道大学土木工程学院,河北石家庄050043 [2]石家庄铁道大学交通工程结构力学行为与系统安全国家重点实验室,河北石家庄050043 [3]中国铁建股份有限公司,北京100855 [4]中铁十八局集团有限公司,天津300222

出　　处：《岩土工程学报》2023年第2期301-309,共9页Chinese Journal of Geotechnical Engineering

基　　金：国家重点研发计划项目(2018YFC0808703,2018YFC0808704);国家自然科学基金项目(52178391);石家庄铁道大学研究生创新资助项目(YC2022001)。

摘　　要：新建隧道下穿既有隧道施工时,由于传统随机介质理论无法考虑既有隧道的影响,地层变形预测结果易出现较大误差。考虑隧道开挖后断面的非均匀收敛,基于随机介质理论与Peck公式两者关键参数之间的关系,对传统随机介质理论进行了简化和改进;应用隧道衬砌抗弯刚度等效及当层法,对非均质地层和既有隧道进行了等效处理,提出了隧道下穿施工引起的既有隧道及地层变形预测模型,结合相关典型工程验证了该理论模型的准确性。结果表明:与传统随机介质理论相比,预测模型对既有隧道及地层的变形预测曲线均呈“宽而浅”的特点,与数值计算及现场实测结果的关联度更大,具有更高的合理性和准确性,为隧道下穿施工引起的既有隧道及地层变形预测提供了理论依据。During the construction of new tunnels undercrossing the existing tunnels,the predicted results of the stratum deformation are prone to large errors since the traditional stochastic medium theory cannot consider the influences of the existing tunnel.Considering the non-uniform convergence of the tunnel section after excavation,the traditional stochastic medium theory is simplified and improved based on the relationship between the key parameters of the stochastic medium theory and those of the Peck’s formula.The heterogeneous strata and existing tunnels are equated by applying the bending stiffness of an existing tunnel and the equivalent layer method.A prediction model for the deformation of the existing tunnels and strata caused by the excavation of new undercrossing tunnels is proposed,and based on the relevant typical project,its accuracy is validated.The results show that compared with those of the traditional stochastic medium theory,the predicted curves of the proposed model are"wide and shallow"and have a greater correlation with the numerical calculations and the field measurements,and they have a higher rationality and accuracy,which may provide a theoretical basis for the prediction of the deformation of the existing tunnels and strata caused by the excavation of undercrossing tunnels.

关 键 词：下穿 随机介质理论 抗弯刚度等效 当层法 非均质地层 

分 类 号：TU45[建筑科学—岩土工程]