路基填筑引起水泥搅拌桩复合地基变形监测分析  

Monitoring Analysis on Composite Foundation Deformation of Cement Mixing Piles Under Subgrade Filling

作　　者：项瑞聪 杨龙才[1,2] 王炳龙[1,2] Xiang Ruicong;Yang Longcai;Wang Binglong(Key Laboratory of Road and Traffic Engineering of the Ministry of Education,Tongji University,Shanghai 201814,China;Shanghai Key Laboratory of Rail Infrastructure Durability and System Safety,Tongji University,Shanghai 201814,China)

机构地区：[1]同济大学道路与交通工程教育部重点实验室 [2]同济大学上海市轨道交通结构耐久与系统安全重点实验室,上海201814

出　　处：《华东交通大学学报》2020年第2期38-45,共8页Journal of East China Jiaotong University

基　　金：国家青年自然科学基金项目(51608384);国家自然科学基金项目(51778485)。

摘　　要：针对目前水泥搅拌桩复合地基在路基填筑作用下变形特性研究不足的问题,依托我国海积软土地区某水泥搅拌桩加固铁路路基填筑施工案例,对水泥搅拌桩复合地基变形进行监测,分析路基填筑作用下水泥搅拌桩复合地基变形特性,并为路基填筑速率控制和水泥搅拌桩加固方案设计提供建议。研究结果表明:路基填筑作用下地基加固区压缩量占总沉降的56.1%,沉降速率最大为2.4 mm/d;素填土和淤泥层侧向变形显著,侧向变形速率最大为4.6 mm/d;路基坡脚7 m内、深度5 m以上地层受路基填筑施工扰动较大;坡脚侧向变形速率较地基沉降速率更接近于控制指标,填筑速率的控制应以控制坡脚侧向变形速率为主;本施工案例中水泥搅拌桩加固方案可满足各铁路类别的路基工后沉降的控制要求,类似工程中水泥搅拌桩设计应以控制路基填筑施工对邻近结构物的影响为主。Aiming at the problem of insufficient research on deformation characteristics of cement mixing piles composite foundation under subgrade filling at present,based on a construction case of railway subgrade filling reinforced by cement mixing piles in marine soft soil areas of China,this study monitored the deformation of composite foundation for cement mixing piles during subgrade filling.The deformation characteristics of composite foundation of cement mixing piles under subgrade filling were analyzed,and suggestions for subgrade filling rate control and cement mixing piles reinforcement scheme design were provided.The results show that the compression of the foundation reinforcement zone accounts for 56.1%of the total settlement under subgrade filling,and the maximum settlement rate is 2.4 mm/d.The lateral deformation of plain fill and silt layer is significant,and the maximum lateral deformation rate is 4.6 mm/d.The strata within 7 m from the foot of subgrade slope and above the depth of 5 m are greatly disturbed by the construction of subgrade filling.The lateral deformation rate of the slope is closer to the control index than the settlement rate of the foundation and the subgrade filling rate should be controlled mainly by controlling the lateral deformation rate of the slope.In this construction case,the cement mixing piles reinforcement scheme can meet the control requirements for post-construction settlement of subgrade of all railway types,the design of cement mixing piles in similar projects mainly controls the influence of subgrade filling construction on adjacent structures.

关 键 词：路基填筑 水泥搅拌桩复合地基 沉降 侧向变形 现场监测 

分 类 号：TU413[建筑科学—岩土工程]