大跨度公铁合建斜拉桥主塔沉井基础沉降变形分析  

Settlement analysis of caisson foundation under main tower of a long span cable-stayed bridge for highway and railway

作　　者：谭国宏[1] 肖海珠[1] 杜勋 胡文军[1] TAN Guo-hong;XIAO Hai-zhu;DU Xun;HU Wen-jun(China Railway Major Bridge Reconnaissance & Design Institute Co.,Ltd.,Wuhan,Hubei 430056,China)

机构地区：[1]中铁大桥勘测设计院有限公司,湖北武汉430056

出　　处：《岩土力学》2019年第3期1113-1120,共8页Rock and Soil Mechanics

摘　　要：高速铁路桥梁基础整体沉降对桥梁线型控制至关重要,而规范中计算整体沉降的分层总和法在深大沉井基础中的适用性有待商榷。以大跨度公铁合建斜拉桥深大沉井基础为工程背景,分别采用摩尔-库仑模型(M-C)、土体硬化模型(HS)和小应变土体硬化(HSS)模型,通过有限元方法,得到了相应的基础沉降曲线。与现场监测数据对比表明,采用HSS模型得到的计算结果与实测值吻合较好。在此基础上,对后续重要施工阶段的沉降趋势进行了合理的预测。与此同时,针对该工程的深大沉井基础,对现有规范分层总和法中的沉降经验系数进行了修正,在该工程中,建议将沉降系数修正为0.13。It is vital to foreknow the overall settlement of bridge foundation for high speed railway in order to keep control of the bridge line. However, it is questionable to calculate the overall settlement of the large caisson foundation at a great depth by using layer-wise summation method recommended in the specification. In this paper, a deep and large caisson foundation under main tower of a long span cable-stayed bridge is taken into account. The overall settlement of caisson foundation is calculated by finite element method(FEM) with Mohr-Coulomb model(M-C), hardening-soil model(HS) and small-strain hardening soil model(HSS),respectively. Compared with the field monitoring data, the numerical results show that the overall settlements with HSS model are in good agreement with the monitoring data. Furthermore, the settlements in the following construction stages are rationally predicted by FEM. For layer-wise summation method recommended in the specification, the empirical settlement coefficient is corrected based on the monitoring data, and it is found that when the empirical settlement coefficient is equal to 0.13, the settlements by summation method are consistent with the monitoring data in this case.

关 键 词：大跨度斜拉桥 沉井基础 基础沉降 小应变土体硬化模型(HSS) 分层总和法 

分 类 号：TU470[建筑科学—结构工程]