圆形内支撑支护在软土深基坑中的应用  

Application of Circular Internal Supporting Systerm of Deep Excavation in Soft Soil

作　　者：蓝媚 张保志 蓝威 LAN Mei;ZHANG Baozhi;LAN Wei(Qingyuan Construction Engineering Comprehensive Service Station Qingyuan Talent Reserve Center ,Qingyuan 511500,China;Guangdong Hongling Construction Engineering Co.,Ltd.,Qingyuan 511500,China)

机构地区：[1]清远市建设工程综合服务站清远市人才储备中心,广东清远511500 [2]广东泓瓴建筑工程有限公司,广东清远511500

出　　处：《广东土木与建筑》2023年第2期74-77,89,共5页Guangdong Architecture Civil Engineering

摘　　要：城市地下空间不断开发,基坑开挖深度、面积越来越大,对周边建(构)筑物的保护要求越来越高,如何确保基坑安全稳定及周边建(构)筑物、地面变形较小的前提下,改善地下结构施工空间,缩短工期,节约资金具有重要的现实意义。以某医院基坑支护工程为例,采用“放坡+钻孔灌注桩+环梁支撑+搅拌桩止水”的支护体系,通过分析计算圆形支撑的内力变形及现场监测,就该支护体系的设计及监测情况进行探讨。结果表明:支撑轴力、基坑支护结构变形、周边建(构)筑物沉降、土体深层水平位移等满足规范及设计要求;对基坑局部薄弱位置进行强化处理,即基坑边中间位置内支撑增加拉结板及软土位置进行坑底被动区加固,能有效减小支护桩变形及圆形内支撑受力;总体上,“放坡+钻孔灌注桩+环梁支撑+搅拌桩止水”的支护体系具有整体稳定性好、施工作业空间大、节约材料的特点,可提升基坑开挖进度,减少施工成本。With the continuous development of urban underground space, the excavation depth and area of foundation pits are getting larger and larger,and the protection requirements for surrounding buildings(structures) are getting higher and higher. It is of great practical significance to improve the construction space of underground structure,shorten the construction period and save funds on the premise of ensuring the safety and stability of foundation pit and small deformation of surrounding buildings(structures) and ground. Taking the foundation pit support project of an hospital as an example, and adopting the support system of “slope+bored pile+ ring beam support+ mixing pile”,by calculating internal forces and deformations of circular supports and monitoring scene,the design and monitor of the support system are discussed. The results show that the axial force of brace,the deformation of the supporting structure of the foundation pit,the settlement of the surrounding buildings(structures) and the horizontal displacement of the deep soil meet the requirements of the code and design. Strengthening the local weak position of the foundation pit,that is adding the tension plate in the middle position of the foundation pit edge and strengthening the passive area of the bottom of the foundation pit in the soft soil position,can effectively reduce the deformation of the supporting pile and the force of the circular internal support. As a whole, the support system of“slope+bored pile+ ring beam support+ mixing pile” has the characteristics of high overall stability, large construction space and material saving, which can improve the excavation progress and reduce construction cost.

关 键 词：圆形内支撑体系 软土 深基坑 监测 

分 类 号：TU745.9[建筑科学—建筑技术科学]