明挖法深大基坑轴向拉压双向受力装配式支撑结构施工技术  

Construction Technology of Assembled Support for Axial Tension and Compression Bidirectional Force in Deep and Large Foundation Excavations Using Open Excavarion Method

作　　者：陈伟[1] 陈晓洁 CHEN Wei;CHEN Xiaojie(Beijing Urban&Rural Construction Group Co.,Ltd.,Beijing100067,China)

机构地区：[1]北京城乡建设集团有限责任公司,北京100067

出　　处：《施工技术（中英文）》2024年第15期26-30,共5页Construction Technology

基　　金：北京建工集团重点攻关项目(SGGA500920220001)。

摘　　要：传统深大基坑钢筋混凝土支撑为现场浇筑,形成支护力慢,拆除困难,钢支撑仅可承受轴向压力且易脱落,结构整体性差。为此,研发具有轴向拉压双向受力性能、可重复利用的装配式支撑结构,该结构主要包括现浇混凝土端头、钢支撑和高强度螺栓。对端头连接方式、受力形式进行优化,对装配式支撑结构施工工艺进行研究,包括基坑放坡开挖、钢支撑架设、高强度螺栓安装、端头钢筋绑扎与浇筑、钢支撑轴力施加与监测、构件拆除。依托青岛市地铁前东城站基坑工程开展装配式支撑结构实际应用,现场监测结果表明装配式支撑结构受力稳定,可发挥良好的内支撑效果,可保证深大基坑开挖安全。The traditional reinforced concrete support for deep and large foundation excavations is poured on site,which results in slow support force and difficult removal.The steel support can only withstand axial pressure and is prone to detachment,resulting in poor overall structural integrity.Thus,an assembled support structure with axial tension and compression bidirectional force performance had been developed,which could be reused.This structure mainly includes cast-in-place concrete ends,steel supports and high-strength bolts.This paper optimizes the connection method and stress form of the ends.The construction technology of assembled support is studied,including excavation of foundation excavation slope,installation of steel support,installation of high-strength bolts,binding and pouring of end steel bars,application and monitoring of steel support axial force and dismantling of components.Based on the foundation excavation project of Qingdao Subway Qiandongcheng Station,the practical application of the assembled support has been carried out.The on-site monitoring results indicate that the assembled support has stable stress and can play a good internal support effect,ensuring the safety of deep and large foundation excavation construction.

关 键 词：地铁 车站 基坑 装配式 支撑 施工技术 

分 类 号：TU94[建筑科学—建筑技术科学]