某超长项目基坑位于广东省海冲积平原地区,紧邻既有建筑、地面明渠、地下地铁区间及管廊等既有建构筑物,基于现场实际监测数据研究了基坑施工过程中周边环境的变形规律,并分别分析了周边建筑物变形预警后采取的应急控制措施和囊体扩张主动控制措施的变形控制效果。结果表明:明挖顺作法基坑内淤泥层开挖施工阶段周边地表沉降、地面明渠结构沉降、基坑地连墙水平位移等增长迅速,该阶段变形量占总变形量的69.37%~98.65%,应加强该阶段的变形控制措施;基坑采用盖挖逆作法或明挖顺作法施工时,紧邻基坑的既有桩基础高层建筑的变形均较小,但对于紧邻基坑的浅基础地面建筑,基坑采用盖挖逆作法较明挖顺作法施工可更好的控制地面建筑变形;当基坑施工引起周边建筑物变形时,通过采用囊体扩张主动控制措施,可有效地控制周边建筑物桩基及桩基顶部承重结构的变形。
This study takes an ultra-long foundation pit project located in the coastal plain of Guangdong Province, adjacent to complex surrounding environments such as existing buildings, surface drainage channels, subway intervals and tube corridors, as its research object, based on the actual on-site monitoring data studies the deformation law of the complex surrounding environment during the construction of the foundation pit, and respectively analyzes the deformation control effect of the emergency control measures and the active control measures of the capsule expansion, which adopted after the deformation warning of the surrounding buildings. The results show that: During the open-cut foundation pit excavation stage, excavation of the silt layer leads to rapid increases in surface settlement settlement deformation of ground drainage structure, and the horizontal displacement of the foundation pit connecting wall. The settlement deformation in this stage accounts for 69.37% to 98.65% of the total deformation, the deformation control measures in this stage should be strengthened. When the foundation pit is constructed by covering top-down method or open-cut sequential construction method, the deformation of the existing pile foundation high-rise buildings, which is adjacent to the foundation pit, is both relatively small, but for shallow foundation ground building, which is adjacent to the foundation pit, the foundation pit is constructed by covering top-down method which can better control the deformation of the ground building than open-cut sequential construction method. When the deformation of the surrounding buildings is caused by the foundation pit construction, adopting the active control measures of capsule expansion can effectively control the deformation of the pile foundation and the load-bearing structure on the top of the pile foundation of the surrounding buildings.
[1] 李凤伟,杜修力,张明聚.地铁工程建设施工事故统计分析[J].地下空间与工程学报,2014,10(2):474-479.
[2] 李皓燃,李启明,陆莹.2002—2016年我国地铁施工安全事故规律性的统计分析[J].都市快轨交通,2017,30(1):12-19.
[3] 郑刚.软土地区基坑工程变形控制方法及工程应用[J].岩土工程学报,2022,44(1):1-36,201.
[4] 张艳书,薛栩超,庄海洋,等.软土层对地铁狭长深基坑地表沉降的影响研究[J].地下空间与工程学报,2018,14(6):1639-1651.
[5] 秦会来,黄俊,李奇志,等.深厚淤泥地层深基坑变形影响因素分析[J].岩土工程学报,2021,43(增2):23-26.
[6] 施有志,柴建峰,赵花丽,等.地铁深基坑开挖对邻近建筑物影响分析[J].防灾减灾工程学报,2018,38(6):927-935.
[7] 杨忠平,刘浩宇,周小涵,等.深厚淤泥土深长基坑开挖对邻近建筑的影响[J].地下空间与工程学报,2022,18(3):1015-1024.
[8] 刘建华,吴绍明,王林枫,等.深长基坑开挖引发邻近建筑群沉降规律研究[J].地下空间与工程学报,2022,18(4):1374-1382.
[9] 朱亚林,张斌,石鸣,等.软土地区狭长深基坑分区开挖对邻近建筑物沉降影响研究[J].隧道建设(中英文),2022,42(增1):166-173.
[10] 徐建宁.综合管廊深基坑施工对邻近桥梁的影响[J].科学技术与工程,2020,20(5):2022-2029.
[11] 陶燕丽,陈康,朱剑锋,等.密集建筑区超深基坑施工全过程环境变形实测分析[J].地下空间与工程学报,2024,20(3):969-977.
[12] 温淑荔.深基坑开挖对紧邻建筑物影响分析及加固措施优化研究[J].现代隧道技术,2020,57(4):98-103.
[13] 刘新荣,刘鹏,周小涵,等.基于变形影响的基坑邻近建筑保护措施研究[J].地下空间与工程学报,2024,20(1):263-275.
[14] 王恒,陈福全,林海.基坑开挖对邻近桥梁桩基的影响与加固分析[J].地下空间与工程学报,2015,11(5):1257-1265.
[15] 王翠,闫澍旺,张启斌.深基坑开挖对邻近桥桩的影响机制及控制措施研究[J].岩石力学与工程学报,2010,29(增1):2994-3000.
[16] 郑刚,苏奕铭,刁钰,等.基坑引起环境变形囊体扩张主动控制试验研究与工程应用[J].土木工程学报,2022,55(10):80-92.
[17] Zheng G,Su Y M,Diao Y,et al.Field measurements and analysis of real-time capsule grouting to protect existing tunnel adjacent to excavation[J].Tunnelling and Underground Space Technology,2022,122:104350.
[18] 王启云,林华明,臧万军,等.深厚软弱地层地下连续墙槽壁稳定性分析[J].科学技术与工程,2018,18(35):58-64.
[19] 罗成恒,魏建华.减少软土深基坑周边环境初始位移的方法探讨[J].岩土工程学报,2012,34(增1):49-53.
[20] 魏纲,木志远,齐永洁,等.考虑地层损失的隔离桩对基坑旁侧盾构隧道变形保护研究[J].岩土工程学报,2024,46(3):480-489.
[21] Diao Y,Bi C,Du Y M,et al.Greenfield Test and NumericalStudy on Grouting in Silty Clay to Control Horizontal Displacement of Underground Facilities[J].International Journal of Geomechanics,2021,21(10):04021178.
[22] Wang L,Zheng G.Numerical analysis on the effect of grouting treatments on recovering deformed tunnels[J].Proceedings of the Institution of Civil Engineers-ground Improvement,2025,178(3):240-257.
[23] Yu J L,Guo J,Zhou J J,et al.A Simplified Theoretical Method for Estimating the Effect of Capsule Grouting Expansion Technology on Controlling Pile Deformation[J].Applied Sciences,2024,14(13):14135449.
[24] 刘树亚,潘晓明,欧阳蓉,等.用钢筋混凝土支撑代替钢支撑的深基坑支护特性研究[J].岩土工程学报,2012,34(增1):309-314.
