自平衡测试技术在PBA暗挖车站基桩承载力测试中的应用  

Application of Self-balanced Test in the Bearing Capacity of Foundation Piles of PBA Station

作　　者：胡运 郭瑞 祝令伟 Hu Yun;Guo Rui;Zhu Lingwei(Beijing Construction Engineering Quality Third Testing Institute Co.,Ltd.,Beijing 100037,China;Beijing Municipal Engineering Research Institute,Beijing 100037,China)

机构地区：[1]北京市建设工程质量第三检测所有限责任公司,北京100037 [2]北京市市政工程研究院,北京100037

出　　处：《市政技术》2024年第8期168-174,共7页Journal of Municipal Technology

摘　　要：随着轨道交通建设的快速发展,在城市核心区建设地铁车站大多数采用PBA法施工。对于双层四导洞暗挖车站最重要的是中桩和边桩的施工,在上层导洞边桩冠梁施工及车站扣拱作用下,中桩作为临时构件,承受上部结构荷载,因此对中桩承载力要求较高,边桩作为车站永久构件,中桩和边桩承载力关系到车站结构安全。为了检验基桩的实际承载力是否满足设计要求,需要对基桩进行静载试验。已有对基桩静载试验的方法如传统堆载法、锚桩法在PBA暗挖车站内无法实施,所以当前对PBA法施工的基桩只能采用自平衡法检测基桩承载力。从某PBA暗挖车站选取边桩B3在钢筋笼埋设荷载箱,进行了自平衡基桩承载力试验,得出上段桩和下段桩荷载-位移(Q-s)曲线,通过上、下段桩Q-s曲线等效转换,最后得出该桩满足设计规定的承载能力。With the rapid development of rail transit construction,pile beam arch(PBA)method are applied in most of the subway stations in the core area of urban core areas.The most important thing for the station by dual-layer four-guide hole method is the construction of the middle and side piles.Under the action of the construction of the side pile beams at the upper guide-hole and station buckle,the middle pile is used as a temporary component to bear the upper structure load.Therefore,requirements for mid-pile bearing capacity are higher.The stile piles are used as permanent components of the station.The bearing capacity of the mid-pile and the side pile are related to the structural safety.In order to test whether the actual bearing capacity of the base pile meets the design requirements,a static load test is needed.The methods of traditional stacking method and anchor pile method cannot be implemented in the PBA dark excavation station,so the self-balanced method are applied.Selected the side pile B3 of a PBA excavation station,the load box are buried in the reinforcement cage to conduct a self-balanced base pile bearing capacity test to get the Q-s curve of the upper and lower piles.Finally,the bearing capacity of the pile meets the design regulations by equivalent conversion.

关 键 词：轨道交通 PBA法 自平衡法 基桩承载力 

分 类 号：U231.4[交通运输工程—道路与铁道工程]