摘要
通过深厚第四系地层高速铁路无砟轨道、有砟轨道路基的现场地基沉降测试研究,对比分析了天然地基、预应力管桩桩筏结构地基的总沉降、分层沉降等特征.测试研究表明,无论是天然地基还是深层处理地基,中等压缩性土地基的总沉降量较小,荷载稳定后沉降收敛速度较快;若能保证足够的预压时间,天然地基工后沉降满足无砟轨道的铺设要求也是有可能的.沉降对比分析表明,桩筏结构具有较好地均化基底应力和横向差异沉降的作用,天然地基总沉降主要由浅层地基压缩变形组成,而桩筏结构地基总沉降主要由深部下卧层组成,加固区沉降仅3~4mm,仅占总沉降的10%左右.管桩桩筏结构地基总沉降约为天然地基总沉降的27.5%,表明桩筏结构对高速铁路深厚第四系地基的总沉降控制是十分有效的.
By the field test and research of foundation settlement of high—speed railway ballastless and ballast track subgrade On deep Quaternary strata,the characteristics of the surface settlement and layered settlement of natural foundation and PHC pipe pile raft structure foundation are comparatively analyzed.The test results show that,whether the natural foundation or deeply treated foundation,the total settlement of medium compressibility soil is small,and the settlement can quickly converge with the stability of the filling load.If the preloading time is enough,it is also possible that the post·construction settlement of natural foundation meets the requirements of ballastless track laying.Settlement comparative analysis shows that,the pile raft structure has good effects of average base force and transverse uneven settlement.The total settlement of natural foundation is mainly composed of shallow foundation deformation,but the pile raft foundation settlement is mainly composed of deep underlying layer.The settlement of reinforced area is only 3—4 mm,only accounted for 10%of the total settlement.The total settlement of PHC pile raft foundation is about 27.5%of the natural foundation settlement.which indicates that pile raft structure is very effective for controlling the total settlement of deep Quaternary strata foundation in high—speed railway.
作者
王亚飞
Wang Yafei(China Railway Siyuan Survey and Design Group Co.Ltd.,Wuhan Hubei 430063,China)
出处
《铁道建筑技术》
2018年第A01期209-212,262,共5页
Railway Construction Technology
基金
原铁道部科技研究开发项目(2010G003-F).
关键词
高速铁路
桩筏结构
地基沉降组成
现场试验
深厚第四系地层
high-speed railway
pile raft structure
component of foundation settlement
site test
deep Quaternary strata
