摘要
结合上海市密集城区某深基坑工程项目,针对采用拱形隔离桩对邻边老旧砖混建筑物进行保护的问题,采用实时监测手段对基坑围护桩、拱形隔离桩、砖混建筑物的变形规律进行全过程分析,对浅基础砖混结构的安全状态及拱形排桩的隔离效果进行评价。结果表明:①浅基础砖混建筑物的保护标准,应考虑建筑物的既有变形影响,并以附加沉降、整体倾斜、相对挠曲度等指标进行合理确定;②不同基坑部位及不同开挖工况下的隔离效果存在显著差异。其中,基坑中部的隔离效果高于南北两侧角部,最高可达63.23%;浅层开挖的隔离效果高于深层开挖,最后一层开挖较首层开挖的隔离效果高出10%~17%;③总体上软土地层拱形隔离桩的隔离效果可达40%~60%,邻近房屋累计最大变形仅3.65 mm,有效保护了建筑物的安全。研究成果对深基坑设计施工中合理考虑隔离桩的隔离效果具有参考价值。
Combined with a deep foundation pit engineering project in dense urban area of Shanghai,aiming at the problem of using arch isolation pile to protect adjacent old brick-concrete buildings,the deformation law of foundation pit retaining pile,arch isolation pile and brick-concrete building is analyzed in whole process by real-time monitoring method.Then the safety state of shallow foundation brick-concrete structure and the isolation effect of arch row piles are evaluated.The results show that:①The protection standard of shallow foundation brick-concrete buildings should consider the influence of existing deformation of buildings,and should be reasonably determined by additional settlement,overall inclination,relative deflection and other indicators.②There are significant differences in the isolation effect of different foundation pit parts and different excavation conditions.Among them,the isolation effect in the middle of the foundation pit is higher than that in the corners of the north and south sides,up to 63.23%;The isolation effect of shallow excavation is higher than that of deep excavation,and the isolation effect of the last excavation is 10%~17%higher than that of the first excavation.③In general,the isolation effect of arch isolation piles in soft soil layer can reach 40%~60%,and the cumulative maximum deformation of adjacent buildings is only 3.65 mm,which effectively protects the safety of buildings.The research results have practical reference value for reasonably considering the isolation effect of isolation piles in the design and construction of deep foundation pits.
作者
陈勇
陈浩
CHEN Yong;CHEN Hao(Shanghai Urban Construction Municipal Engineering Co.,Ltd.,Shanghai 200032,China;Department of Geotechnical Engineering,Tongji University,Shanghai 200092,China)
出处
《建筑施工》
2024年第4期463-467,共5页
Building Construction
基金
上海城建市政工程(集团)有限公司科研开发项目(2022-A类-QT-003)。
关键词
软土深基坑
拱形隔离排桩
砖混建筑物
隔离效果
soft soil deep foundation pit
arch-shaped isolation row piles
brick-concrete buildings
isolation effect
