真空-堆载预压联合管桩-土工格室在堆场深厚软基处理中的应用  

Mechanism and application of vacuum-surcharge preloading combined with prestressed pipe pile-geocell in deep soft foundation treatment of storage yard

作　　者：陈维家 刘维正[2] 林震宇 CHEN Weijia;LIU Weizheng;LIN Zhenyu(Zhuhai Communications Group Co.,Ltd,Zhuhai 519000,China;School of Civil Engineering,Central South University,Changsha 410075,China;Guangdong Geological Engineering Company,Guangzhou 510000,China)

机构地区：[1]珠海交通集团有限公司,广东珠海519000 [2]中南大学土木工程学院,湖南长沙410075 [3]广东省地质工程公司,广东广州510000

出　　处：《铁道科学与工程学报》2020年第7期1699-1709,共11页Journal of Railway Science and Engineering

基　　金：珠海交通集团有限公司科技研究开发计划资助项目(JT-KT202001);湖南省自然科学基金面上资助项目(2019JJ40344)。

摘　　要：以珠海某堆场深厚软土地基处理工程为依托,针对传统的地基处理方法难以满足该重载堆场工程对深厚软土地基处理的高承载力与稳定性、高标准工后与差异沉降控制、大面积快速高效经济处理的要求,提出先对整个场地进行真空联合堆载预压,再采用“预应力管桩-土工格室加筋土”处理料条区、采用土工格栅加筋土处理堆取料机区的综合处治方案。通过承载力、沉降和侧向位移现场监测对处治效果进行分析,深入探讨综合处治技术的加固机理:管桩桩顶上部加筋土的“土拱效应”可有效扩散应力,同时土工格室起到水平向约束管桩、协调不均匀沉降作用,充分发挥桩筏基础中的柔性筏板作用。研究结果表明:真空-堆载预压联合预应力管桩-土工格室能够大幅度提升地基承载力、限制地基水平位移和减小地基不均匀沉降,有效解决堆场软基过量沉降与稳定性不足的问题。研究结果可为类似工程的深厚软基处理借鉴和利用。A deep soft soil foundation treatment project of a storage yard in Zhuhai,China was studied.Traditional foundation treatment countermeasures cannot meet the requirements of this storage yard project,such as high bearing capacity and stability,high-standard post-construction settlement and differential settlement control,and rapid,efficient and cost-effective treatment of wide areas.A comprehensive solution was thus proposed where the vacuum-surcharge was used to preload the entire yard foundation,and the prestressed pipe piles in combination with geocell reinforcement were then used to treat the sacking areas and geogrid reinforcement to treat the stacker and reclaimer areas.The strengthening mechanism of this comprehensive treatment technology was investigated.It is found that the soil arching effect of reinforced soils on the top of pipe piles can effectively transfer the stress,and that the geocell reinforcement plays a role in restraining the pipe piles horizontally,coordinating the uneven settlements,and producing a remarked effect of flexible raft slabs in pile-raft foundation.Then the treatment performance was analyzed by using in-situ monitoring data of bearing capacity,settlement,and lateral displacement responses.The field data indicate that the solution of vacuum-surcharge preloading combined with prestressed pipe pile-geocell can greatly improve the bearing capacity of soft foundation,control the horizontal displacement of soft foundation and reduce differential settlement of soft foundation.Therefore,the engineering problems of excessive settlement and instability of the storage yard in soft foundation were solved effectively.The results could provide technical reference and guidance for similar projects in deep soft foundation treatment.

关 键 词：深厚软土 大面积堆场 管桩-土工格室复合地基 真空-堆载预压 处治效果 

分 类 号：TU470[建筑科学—结构工程]