微型钢管桩托换已有建筑物桩筏基础的应用研究  

Research on application of micro-steel pipe pile underpinning piled raft foundation of existing building

作　　者：朱彦鹏[1,2] 吕向向 杨奎斌 吴林平 韦正德 施多邦 ZHU Yanpeng;LYU Xiangxiang;YANG Kuibin;WU Linping;WEI Zhengde;SHI Duobang(School of Civil Engineering,Lanzhou University of Technology,Lanzhou 730050,Gansu,China;Western Engineering Research Center of Disaster Mitigation in Civil Engineering of Ministry of Education,Lanzhou University of Technology,Lanzhou 730050,Gansu,China)

机构地区：[1]兰州理工大学土木工程学院,甘肃兰州730050 [2]兰州理工大学西部土木工程防灾减灾教育部工程研究中心,甘肃兰州730050

出　　处：《建筑科学与工程学报》2023年第4期171-178,共8页Journal of Architecture and Civil Engineering

基　　金：教育部长江学者创新团队支持计划项目(IRT_17R51)。

摘　　要：为了研究微型钢管桩托换加固已有桩筏基础建筑的实际应用,以三门峡市某已有桩筏基础建筑物的基础托换工程为例,对已经产生倾斜的16层已有建筑物进行事故原因分析,结合以往实际工程案例经验以及各加固方法优缺点对比,最后采用微型钢管桩托换基础和外扩筏板基础相结合的加固方案。通过单桩竖向承载力计算、稳定性计算以及现场原位试桩,确定微型钢管桩施工工艺以及控制参数,利用现场沉降位移监测,对托换加固方案效果进行评价。结果表明:微型钢管桩托换和外扩筏板基础相结合的加固方案不仅施工工期短,加固机理明确,而且施工期间对建筑物扰动较小,综合加固效果显著;根据监测数据,测点DX1、DX2和DX7处累计沉降量相对较大,其中测点DX1处最大累计沉降位移为-81.1 mm,测点DX7处最大日均沉降为-1.23 mm;被加固的已有建筑物在施工完微型钢管桩大约15 d以后,日均沉降位移稳定控制在0~0.05 mm·d^(-1)之间;研究成果可为填方区地基不均匀沉降加固设计提供一定的参考。In order to study the practical application of micro-steel pipe pile underpinning piled raft foundation of existing building,a foundation underpinning project of an existing piled raft foundation building in Sanmenxia city was taken as an example.The cause of the accident of the existing 16-story building that has been inclined was analyzed.Combined with the previous actual engineering case experience and the comparison of the advantages and disadvantages of each reinforcement method,and finally a reinforcement plan combining the underpinning of micro-steel pipe pile underpinning and the externally expanded raft foundation was adopted.Through the calculation of vertical bearing capacity of single pile,stability calculation and field test pile,the construction technology and control parameters of micro-steel pipe pile were determined,and the field settlement monitoring was used to evaluate the effect of the underpinning reinforcement scheme.The results show that the reinforcement scheme combining micro-steel pipe pile underpinning and externally expanded raft foundation not only has short construction period and clear reinforcement mechanism,but also has less disturbance to buildings during construction,and the comprehensive reinforcement effect is remarkable.According to the monitoring data,the cumulative settlement at the measuring points DX1,DX2 and DX7 are relatively large.The maximum cumulative settlement at the measuring point DX1 is-81.1 mm,and the maximum daily settlement at the measuring point DX7 is-1.23 mm.About 15 d after the construction of the micro-steel pipe piles,the average daily settlement of the reinforced existing building is stably controlled between 0 and 0.05 mm·d^(-1).The research findings can provide some reference for the reinforcement design of uneven settlement of foundation in filling area.

关 键 词：已有建筑 托换技术 微型钢管桩 施工监测 加固效果 

分 类 号：TU929[建筑科学—建筑设计及理论]