孔内深层超强夯法与灌注桩组合在大厚度杂填土地基处理中的应用  

Application of Super Down Hole Dynamic Consolidation and cast-in-placepile combination in the treatment of thick miscellaneous fill soil foundation

作　　者：吕雪漫 刘帅 施怡 张鹏 任小江 穆国峰 LV Xue-man;LIU Shuai;SHI Yi;ZHANG Peng;REN Xiao-jiang;MU Guo-feng(China JIKAN Research Institute of Engineering Investigations and Design,Co.,Ltd.,Xi’an 710021,Shaanxi,China;Shaanxi Key Laboratory of Engineering Behavior and Foundation Treatment for Special Soil,Xi’an 710043,Shaanxi,China;School of Geological Engineering and Geomatics,Chang’an University,Xi’an 710054,Shaanxi,China)

机构地区：[1]机械工业勘察设计研究院有限公司,陕西西安710021 [2]陕西省特殊土工程性质与处理技术重点实验室,陕西西安710043 [3]长安大学地质工程与测绘学院,陕西西安710054

出　　处：《地基处理》2023年第6期506-511,共6页Journal of Ground Improvement

基　　金：机勘院科技研发基金(KYXMN20230011);陕西省住房城乡建设科技项目(2020-K36)

摘　　要：随着城市建设范围和规模的不断增大,遇到越来越多的大厚度杂填土场地。大厚度杂填土地基处理是工程建设的关键,若处理不当,后期建筑物地基易出现不均匀沉降,威胁建筑物安全。本文以西安某工程为例,分析评价了孔内深层超强夯法(Super Down Hole Dynamic Consolidation,SDDC)与灌注桩组合在大厚度填土场地高层建筑物建设中的应用。所研究的建筑物基底下杂填土厚7.5 m,杂填土下的原状黄土层具湿陷性。SDDC处理时,采用冲击成孔工艺,与灌注桩重合位置以素土为填料,其他位置就地取材用杂填土为填料。采用SDDC与灌注桩组合处理地基后,通过地基检测、建筑物沉降观测,所得数据表明该地基方案有效提高了杂填土的密实度,消除了黄土的湿陷性,满足了灌注桩承载力的要求,建筑物沉降小。场地成功运用了SDDC与灌注桩组合处理的方案,可为类似场地工程建设提供借鉴。With the continuous expansion of urban construction in terms of scope and scale,more and more large thickness miscellaneous fill sites are encountered.The treatment of thick and miscellaneous fill soil foundation is pivotal in engineering construction.Neglecting appropriate treatment may result in uneven settlement of the building foundation in later stages,thereby posing a threat to the structural integrity of building.This work takes a project in Xi’an as an example to analyze and evaluate the application of the combination of Super Down Hole Dynamic Consolidation(SDDC)and castin-place piles in the construction of high-rise buildings on thick fill sites.The thickness of miscellaneous fill under the studied building foundation is 7.5 m,and the undisturbed loess layer under the miscellaneous fill has collapsibility.In the application of SDDC,the impact drilling process is employed.At the overlapping point with the cast-in-place pile,plain soil serves as the filling material,while miscellaneous soil is used at other locations.Following the implementation of the SDDC and cast-in-place pile combination for foundation treatment and subsequent foundation testing and building settlement observations,the results show that this foundation scheme significantly enhances the compaction of miscellaneous fill soil,eradicates loess collapsibility,meets the bearing capacity requirements of cast-in-place piles,and reduces building settlement.The successful application of the SDDC and cast-in-place pile combination at this site can serve as a valuable reference for similar engineering construction projects.

关 键 词：SDDC 灌注桩 大厚度填土 地基处理 冲击成孔工艺 

分 类 号：TU47[建筑科学—结构工程]