摘要
目前针对软土基坑开挖诱发邻近小曲率半径隧道变形的理论研究一般将地基视为线弹性体,未考虑土体流变特性的影响,且较少分析曲型隧道变形的特性,因此无法准确预测时间效应下基坑开挖对既有小曲率半径隧道变形的影响。首先,建立分数阶Merchant黏弹性软土基坑开挖诱发邻近既有小曲率半径隧道变形力学模型,按照Laplace时域变化特性推导出分数阶黏弹性土体Laplace域参数;其次,基于基坑卸载和Mindlin应力解理论,求解出邻近既有小曲率半径隧道上附加应力场,再根据Pasternak地基和Timoshenko梁理论,通过有限差分法和Laplace正逆变换推导出既有小曲率半径隧道径向和竖向变形时域解;最后,将工程实测数据及三维数值模拟结果与解析解进行对比验证,得到了较好的一致性。
At present,the theoretical research on the deformation of adjacent tunnels with small curvature radius induced by excavation in soft soil generally regards the foundation as a linear elastic body,without considering the influence of soil rheological characteristics,and seldom analyses the deformation characteristics of curved tunnels,so it is impossible to accurately predict the influence of excavation on the deformation of existing tunnels with small curvature radius under time effect.Firstly,a mechanical model for the deformation of the adjacent existing tunnel with small curvature radius induced by the excavation of the fractional order Merchant viscoelastic soft soil foundation pit is established,and the Laplace domain parameters of the fractional order Merchant viscoelastic soft soil are derived according to the Laplace time-domain variation characteristics.Secondly,based on the theory of foundation pit unloading and Mindlin stress solution,the additional stress field on the adjacent existing tunnel with small curvature radius is solved.According to the theory of Pasternak foundation and Timoshenko beam,the radial and vertical deformation time-domain solutions of the existing tunnel with small curvature radius are derived by finite difference method and Laplace forward and inverse transformation.Finally,the measured data and 3D numerical simulation results are compared with the analytical solution,and good consistency is obtained.
作者
张治国
陈胤吉
魏纲
倪寅
李骏杰
师敏之
木林隆
ZHANG Zhiguo;CHEN Yinji;WEI Gang;NI Yin;LI Junjie;SHI Minzhi;MU Linlong(School of Environment and Architecture,University of Shanghai for Science and Technology,Shanghai 200093,China;Shanghai Pudong New Area Construction(Group)Co.,Ltd.,Shanghai 200137,China;Department of Civil Engineering,Hangzhou City University,Hangzhou 310015,China;Zhejiang Engineering Research Center of Intelligent Urban Infrastructure,Hangzhou 310015,China;Department of Geotechnical Engineering,Tongji University,Shanghai 200092,China)
出处
《岩土工程学报》
北大核心
2025年第9期1793-1803,共11页
Chinese Journal of Geotechnical Engineering
基金
国家自然科学基金项目(52478402,42177145)
城市基础设施智能化浙江省工程研究中心课题项目(UI2022-YB-01)
上海市浦东新区建设(集团)有限公司技术课题项目。
关键词
基坑开挖
黏弹性地基
分数阶
时域解
小曲率半径隧道
变形
excavation
viscoelastic foundations
fractional order
time-domain solution
tunnel with small curvature radius
deformation
