上穿隧道引起既有隧道变形的黏弹性分析  

Viscoelastic Analysis of Deformation of the Existing Tunnel Due to the Above-Crossing Tunneling

作　　者：陈华东 申文明 张文杰[1] CHEN Huadong;SHEN Wenming;ZHANG Wenjie(School of Mechanics and Engineering Science,Shanghai University,Shanghai 200444,China;CREETC East China Survey and Design Co.,Ltd.,Hangzhou 310004,Zhejiang,China)

机构地区：[1]上海大学力学与工程科学学院,上海200444 [2]中铁二院华东勘察设计有限责任公司,浙江杭州310004

出　　处：《力学季刊》2022年第4期958-969,共12页Chinese Quarterly of Mechanics

基　　金：国家自然科学基金(41772300)。

摘　　要：为了研究软土地基中新建隧道开挖卸荷对下卧既有隧道结构变形的影响,考虑地基黏弹性性质,应用两阶段法和Laplace变换法,将既有隧道视为搁置在Pasternak黏弹性地基上的Euler-Bernoulli梁,推导出了既有隧道结构纵向变形的黏弹性解答.并与现场实测和数值模拟结果进行了比对,根据解答分析了相关参数对既有结构变形的影响.研究发现,案例中新建隧道开挖完成后既有隧道变形随时间继续发展,经120 d左右变形才趋于稳定,施工完成后的流变变形占总变形量的23.1%.其流变变形随新建隧道开挖宽度、弹性体(H体)剪切模量增加而增大,随既有隧道轴线埋深增加而减小.黏性系数增大,既有隧道结构变形达到稳定的时间延长,但并不影响其变形总量.To study the deformation of existing tunnel caused by the construction of new tunnel in soft ground, the existing tunnel was considered as an Euler-Bernoulli beam resting on a Pasternak viscoelastic foundation. Considering the viscoelastic properties of the foundation, a viscoelastic solution for the structural deformation of existing tunnel was derived by applying the two-stage method and the Laplace transform. The results were also compared with the results of field measurements and numerical simulations, and the influence of the relevant parameters on the deformation of the existing tunnel was analyzed according to the theoretical solution. The results show that the deformation of the existing tunnel develops with time after the excavation is completed, and takes around 120 d to reach a steady state. The rheological deformation of the tunnel structure accounts for about23.1 % of the total deformation at the completion of the construction in this case. The increase in excavation width, elastic body(Hbody) shear modulus and the decrease in the burial depth of the existing tunnel axis lead to an increase in the rheological deformation. More time is required for the deformation of existing tunnel to reach stable stage for larger viscosity coefficient, but there is no significant difference in the final deformation of the tunnel structure for different viscosity coefficients.

关 键 词：黏弹性分析 初参数法 两阶段法 流变模型 

分 类 号：U45[建筑科学—桥梁与隧道工程]