装配式钢支撑基坑支护结构体系基坑开挖与稳定性模拟分析

FOUNDATION EXCAVATION AND STABILITY ANALYSIS OF RETAINING PREFABRICATED STEEL-BRACED FOUNDATION EXCAVATION SUPPORT SYSTEM

针对目前基坑支护体系造价高、不可重复利用、拆除难度大等问题,设计开发了一套基坑工程中可重复利用的装配式钢支撑支护体系。该体系由按照标准化规格生产的钢支撑、连接节点、竖向支撑组成,所用钢支撑、钢支撑连接节点均由工厂预制成型,钢支撑与连接节点的外伸短臂通过法兰盘连接。该节点受力明确、构造简单、施工质量可控、拆除后可重复利用。首先,结合天津某工程实例,采用ABAQUS有限元分析软件建立考虑基坑分布开挖的模型,证明了装配式钢支撑支护体系的可行性。最后,采用ANSYS有限元分析软件对装配式钢支撑支护结构体系进行了特征值屈曲分析及非线性特征值屈曲分析,并比较了添加腹杆对结构的影响。结果表明:增加腹杆对于装配式钢支撑支护体系来说有部分稳定性的提升,但提升相对有限。

Aiming at the problems of high cost, non-reusable and difficult demolition of foundation excavation support system, a set of assembled steel support system which can be reused in foundation excavation engineering is designed and developed. The system consists of steel braces, connection joints and vertical braces produced in accordance with standardized specifications. The steel braces and steel support connection joints used are prefabricated. The steel brace and the overhanging short arm of the connecting joint were connected through the flange. The joint has clear force, simple structure, controllable construction quality and can be reused after demolition. Firstly, based on an engineering example in Tianjin, the feasibility of the prefabricated steel support system was proved by using ABAQUS finite element analysis software to establish a model considering the foundation excavation. Lastly, the eigenvalue buckling analysis and the non-linear eigenvalue buckling analysis of the prefabricated steel support structure system were carried out by using ANSYS finite element analysis software. The influences of web members on the structure were also compared. The results showed that the increase of web members could improve the stability of the prefabricated steel support system, but it was relatively limited.