现浇X形桩复合地基拓宽高速公路路基沉降计算方法研究  

Analysis on Calculation Method for Widen Expressway Settlement with X-section Cast-in-place Concrete Pile Composite Foundation

作　　者：於慧[1] 丁选明[1] 吕亚茹[1] 

机构地区：[1]河海大学岩土力学与堤坝工程教育部重点实验室河海大学水资源高效利用与工程安全国家工程研究中心,南京210098

出　　处：《防灾减灾工程学报》2013年第1期84-90,共7页Journal of Disaster Prevention and Mitigation Engineering

基　　金：国家自然科学基金项目(51008115);国家自然科学基金高铁联合基金重点项目(U1134207)资助

摘　　要：软土路基沉降计算是高速公路拓宽工程中的重要课题。以南京长江四桥南接线栖霞互通312国道拓宽段采用现浇X形桩处理的软基路段为背景,推导出现浇X形桩拓宽路基的附加应力和沉降计算方法,采用附加应力叠加的方式计算拓宽新路堤引起的附加应力,在沉降计算中引入充盈折减系数以反映异形桩的截面效应,建立了现浇X形桩拓宽路堤的沉降计算简化公式。分析了全部路堤、老路堤和新路堤下附加应力和沉降分布规律并与现场监测结果进行对比,对拓宽工程沉降的主要影响因素进行了讨论,分析了不同拓宽宽度和坡比下附加应力及沉降分布规律。Widening of old road on soft ground is found to be a very important issue in the high- way construction engineering. The method for calculating additional stress and settlement is giv- en based on the widening project of Qixia State Road 312, which is connecting to the Forth Nanjing Yangtze River Bridge. In this paper, the principle of additional stress superposition has been used to calculate the additional stress arise from new embankment. The filling coefficient was taken into account to reflect the section effect of special-shaped column in settlement calculation. A simplified formula was established in the settlement calculation of new embankment reinforced by cast-in-place X section pile. The distribution law of additional stress and settlement was ana- lyzed, as well as compared with site data. It has been observed that the widened extent and the slope of old embankment significantly influence the settlement o{ widening construction.

关 键 词：现浇X形桩 公路拓宽 附加应力 软土地基 沉降 复合地基 

分 类 号：TU411[建筑科学—岩土工程]