地下工程盘扣式钢管支撑架侧向承载性能与计算方法研究
作者简介:
施耀锋,高级工程师, E⁃mail:syfstec@ 163. com
作者单位:
上海隧道工程有限公司,上海 200032
基金项目:
∗上海市科技计划项目(23DZ1202903)
摘要:
在地下工程混凝土侧墙浇筑过程中,盘扣式脚手架常被用作侧向支撑结构以承受侧向水平荷载,这对其侧向承载力和刚度提出了要求. 盘扣式脚手架侧向承载性能与竖向承载性能存在明显不同. 为此,对盘扣式钢管支撑架侧向承载性能与计算方法开展试验研究、有限元分析与理论分析. 侧向荷载下的足尺承载力试验结果表明:支撑架表现出中部侧向位移大、上下两端侧向位移小的基本变形特征,破坏模式包括下部立杆弯剪破坏、斜撑杆受压屈曲破坏及连墙件破坏. 通过采用线性梁单元模拟钢管构件、采用弹簧单元模拟盘扣式节点的半刚性特性,所建立的有限元模型能准确模拟盘扣式钢管支撑架侧向承载性能. 基于刚度特征,可将下端地锚梁简化为铰支座、上端连墙件简化为弹簧支座,从而建立设置弹簧支座的简支梁模型,用于计算侧向荷载作用下盘扣式钢管支撑架最大侧向位移.

English:
In side⁃wall concrete pouring projects of underground engineering, the disk lock scaffold wasoften used as a lateral support structure to bear lateral horizontal loads, which required to concerned itslateral bearing capacity and lateral stiffness. The lateral load⁃bearing behavior and vertical load⁃bearingbehavior of disk lock scaffold were significantly different. The experimental research, finite elementanalysis and theoretical analysis on the lateral bearing performance and calculation method of disk locksteel tubular support frame were conducted . The full⁃scale bearing capacity tests of the disk lock steeltubular support frame under lateral load showed that the support frame exhibited the deformationcharacteristics of large lateral displacement in the middle and small lateral displacement in the upper andlower parts. The failure modes included the bending and shearing failure of the lower standards, thecompression and buckling failure of the diagonal braces, and the failure of the tie components. The linearbeam elements were adopted to simulate the steel tube components, and the spring elements were used tosimulate the semi⁃rigid characteristics of the disk lock joints. The established finite element model couldaccurately simulate the lateral bearing performance of disk lock steel tubular support frame. Through thesimply supported beam model with spring supports, the maximum lateral displacement of the disk locksteel tubular support frame under lateral load could be calculated. According to its stiffnesscharacteristics, the lower ground anchor beam was simplified as a hinged support, while the upper walltie was simplified as a spring support, so as to establish a simply supported beam model with a springsupport, which was used to calculate the maximum lateral displacement of the disk lock steel tubular support frame under lateral load.