高速铁路桥梁桩基固结蠕变沉降计算方法研究  

A method for calculating the consolidation and creep-induced settlement of bridge pile foundation of high-speed railway

作　　者：周涛[1,2] 徐方 杨奇[1,3] 吴亚飞[1] ZHOU Tao;XU Fang;YANG Qi;WU Yafei(College of Civil Engineering,Central South University,Changsha 410075,China;T.Y.Lin International Engineering Consulting(China)Co.,Ltd.,Chongqing 401121,China;National Engineering Laboratory for High-Speed Railway Construction Central South University,Changsha 410075,China)

机构地区：[1]中南大学土木工程学院,湖南长沙410075 [2]林同棪国际(中国)工程咨询有限公司,重庆401121 [3]中南大学高速铁路建造技术国家工程试验室,湖南长沙410075

出　　处：《铁道科学与工程学报》2021年第8期1968-1977,共10页Journal of Railway Science and Engineering

基　　金：国家自然科学基金资助项目(51478478,51208518);重庆在渝院士牵头科技创新引导专项项目(cstc2019yszx-jcyjX0009);中国中铁横向科研项目(HSTZQ7(JSFW)-2020-15)。

摘　　要：桥梁桩基工后沉降的控制是高速铁路桥梁设计和施工的关键技术之一,其中桩基的长期固结蠕变沉降计算分析又是关键环节。经过现场调研分析提出高速铁路桥梁桩基实际受荷—时间关系的函数表达式。建立多级荷载作用下的多层黏弹性地基单面排水或两面排水条件下的一维固结方程,并基于Laplace数值逆变换推导桩底压缩层在多级荷载作用下的有效应力和沉降计算公式。基于此,提出能模拟高速铁路桥梁桩基实际加载情况和考虑桩底成层土固结蠕变特性的桩基长期沉降计算方法。为提高计算效率,编写相应的群桩长期沉降计算分析程序LTPGSⅡ。京沪高铁桥梁桩基沉降计算结果和现场实测值的对比验证了计算方法及程序的正确性和可靠性。提出的计算方法能用于高速铁路桥梁桩基长期沉降预估,具有重要的理论价值和工程应用价值。To design pile foundations supporting high-speed railway bridges,it is an essential requirement to predict their consolidation and creep-induced settlements.In this study,the time-dependent loading formula on pile foundation was presented.One-dimensional consolidation equation of visco-elastic and multilayered soils with single drainage or double drainages under multistage loading was established.The formulas of the effective stress and settlement under multistage loading were derived from the Laplace numerical inversion transform.A method was proposed to predict the long-term settlements of bridge pile foundations,which can consider the timedependent loading process as a result of the construction process of the superstructure on a bridge pile foundation and the consolidation and creep behavior of the supporting layers below the pile ends.A program named LTPGSⅡ(the second edition of a program for calculating the long-term settlement of pile foundation)was developed to improve the computational efficiency of the proposed method.The long-term settlement of a well-documented field test of a bridge pile foundation in the Beijing-Shanghai high-speed railway was predicted,and the results agreed well with the measured data,indicating that the developed method and program are reliable and accurate.The proposed calculation method has been used to predict the long-term settlement of high-speed railway bridge pile foundations,and has important theoretical and engineering application value.

关 键 词：高速铁路 桥梁桩基 固结蠕变沉降 Laplace数值逆变换 多级加载 

分 类 号：TU473[建筑科学—结构工程]