高速铁路站场咽喉区复合地基的工程特性研究  

Research on Consolidation Characteristics of Composite Foundation in the Throat Area of High-speed Railway Station

作　　者：李懿[1,2] 王连俊[1] 栾光日[1,3] 张光宗[1] 

机构地区：[1]北京交通大学土木建筑工程学院,北京100044 [2]北京市市政工程设计研究总院有限公司,北京100082 [3]京沪高速铁路济南高速站工程建设指挥部,山东济南250001

出　　处：《铁道学报》2014年第12期90-96,共7页Journal of the China Railway Society

基　　金：铁道部科研项目(2008G032-A)

摘　　要：结合京沪高速铁路济南西客站工程实际,对站场咽喉区深厚软土大面积堆载预压下复合地基的工程特性开展现场试验研究,分析不同位置和深度的超孔隙水压力、沉降变形以及桩土应力等参数随时间和填土高度的变化规律,为该地区同类工程设计和施工提供科学依据。研究结果表明:站场咽喉区复合地基内的超孔隙水压力随着荷载的增加而增大,达到峰值后消散,其变化略滞后于荷载的变化;超孔隙水压力的最大值出现在下卧层上部;在下卧层中,随着深度的增加,超孔隙水压力逐渐减小。站场咽喉区复合地基最大沉降发生在25m CFG桩加固区的中部,35mPHC管桩有效减小了站场中心区的沉降。主要压缩量发生在加固区底部和下卧层。站场咽喉区复合地基由路堤中心向外,桩应力、桩间土应力及桩土应力比总体呈减小趋势。在路堤填筑和预压中,站场咽喉区复合地基桩间土应力向桩传递,桩间土应力逐渐减少,桩顶应力逐渐增大,并逐渐趋于稳定。Experimental study was carried out on engineering characteristics of the thick soft-soil composite foundation under large-area preloading in the throat area of the Jinan West Railway Station of the Beijing-Shanghai High-speed Railway.The changing law of excess pore water pressures,settlement deformations and pile-soil stresses at different positions and depths with time and soil filling heights was analyzed,thus providing theoretical basis for design and construction of engineering projects of a kind in the same area.The research results show as follows：（1）Excess pore water pressures of the composite foundation in the station throat area increase with growth of loads and upon reaching their peak value gradually scatter and disappear as time prolongs.The change of excess pore water pressures lags behind the change of loads slightly.The maximum excess pore water pressure appears in the upper part of under layer.In the underlayer,excess pore water pressures decrease gradually with increasing of depths.（2）For the composite foundation of the station throat area,the settlement reaches the maximum in the middle of the area reinforced with Pile 25 m CFG.Pipe Pile 35 m PHC effectively decreases the settement in the centre area of the station.Major compression settling happens at the bottom of the reinforced area and in the underlayer.（3） For the composite foundation of the station throat area,pile stresses,inter-pile soil stresses and pile-soil stress ratios demonstrate a generally decreasing trend from the centre of embankment outwards to edges.In embankment filling and preloading inter-pile soil stresses are passed on to piles in a gradually decreasing manner while pile-top stresses increase gradually until tending to get stablized.

关 键 词：复合地基 堆载预压 超孔隙水压力 桩土应力 沉降变形 

分 类 号：U213.1[交通运输工程—道路与铁道工程]