高层建筑物桩基托换的受力分析与接头强度试验

Mechanical Analysis and Joint Strength Tests of Pile Underpinning for High-rise Building

桩基托换在地下工程建设中是一项科技含量较高的应用性技术,深圳地铁一期工程国贸—老街区间隧道从百货广场大楼下桩基丛中穿过托换,该工程具有桩的荷载大、地层条件复杂、地下水位高、托换深度大等特点,难度较大。为给设计和施工提供理论依据,建立了百货广场大厦桩基托换区域的托换过程空间力学模拟分析模型,采用ANSYS软件对托换过程中百货广场结构及桩基的托换大梁进行了力学分析,并进行了1∶4梁柱接头模型试验,通过试验选择合理的接头型式并确定其实际承载能力,检验其可靠性,确保了大楼桩基托换顺利进行。该工程施工过程中及竣工后,沉降变形未超过允许值。

Pile underpinning is an application technique with a high content of science and technology in underground engineering construction. The Guomao-Laojie subway tunnel of the first stage of Shenzhen metro passes through the pile zone of a department plaza building and needs underpinning construction. The project has great difficulty because of the heavy load of the piles, the complicate ground condition,the high ground water level,and the depth of underpinning,etc.In order to provide theoretical basis for the design and construction,a spatial mechanical analysis model is established for the underpinning course of the corresponding construction area.The well-known ANSYS software is used to make the mechanical analysis of the building and the girder of underpinning piles,and 1∶4 model tests for the column-beam joint is carried out.Proper joint pattern is selected,the practical bearing capacity is determined and the reliability is verified,so that smooth construction of the underpinning is ensured and the settlement does not exceed the allowable value during and after the construction.