对京沪高速铁路济南西客站PHC管桩和CFG桩联合堆载预压处理宽站场复合地基的沉降特性开展试验研究，监测不同宽度、不同桩型和桩长复合地基的地表沉降及分层沉降，分析沉降变形随路堤填筑高度和时间的变化规律，研究路基宽度对沉降量和沉降曲线形状的影响。研究结果表明：站场路基沉降-时间曲线包含沉降发展阶段（路基填筑阶段）、沉降快速发展阶段（堆载预压土至2～3个月静置期）和沉降基本稳定阶段；宽大站场PHC管桩及CFG桩复合地基在中心区附近呈现沉降洼地，而在中央区沉降洼地的两侧出现次一级沉降洼地；宽大站场PHC管桩及CFG桩复合地基附加应力较大，衰减速度慢，沉降影响深度大，30～50 m以下的地基沉降量约占总沉降的75％～85％，加固区范围内沉降量占总沉降的5％～10％。%Experimental study was carried out on settlement characteristics of the preloaded PHC pipe pile and CFG pile composite foundation of the JinanWest Railway Station of the Beijing-Shanghai High-speed Railway . Surface settlement and layer settlement of the composite foundation with different widths and with piles of dif-ferent types and lengths were observed . The changing law of settlement deformations with embankment fill heights and time was analyzed . The influence of subgrade widthson the settlement magnitude and shape of set-tlement curve was investigated . The research results show as follows :The settlement-time curve of station subgrade includes the settlement development stage(the subgrade construction stage) , the rapid settlement de-velopment stage(the stage from soil preloading to 2~3 months standing ) and the basically stable settlement stage ;For the PHC pipe pile and CFG pile composite foundation of a large station ,a settlement depression ar-ea appears around the center of the station and secondary settlement depression areas appear on both sides of the center settlement depression area ;For the PHC piple pile and CFG pile composite foundation of a large sta-tion , the additional stress is large , its attenuating speed is low and settlement affects deeply ;settlement of foundation below 30~50 m takes up about 75% to 85% of the total settlement and settlement within the rein-forced areas takes up 5% to 10% of the total settlement .
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