T型抗震柱的悬挑方案设计与安全验算

Design and Safety Checking Calculation of Cantilever Scheme for T-shaped Seismic Columns

依据案例的现场情况,设计并验算了不完全规范搭设的悬挑脚手架安全性能。采用数值分析的方法建立结构简化和细化两种模型,用Midas Civil先计算出悬挑结构简化模型连接点的受力情况;再使用平面单元建立的焊缝、螺栓等细化模型,验算悬挑细部结构的承载安全能力;最后用XTRACT分析结构梁柱截面,验算已建成结构承载能力。考虑风荷载作用下,拟定方案符合力学承载要求,各杆系与型钢承载能力仅发挥约30%,除螺栓、耳板和焊缝达到70%左右利用率,其他局部材料特性未能充分利用;悬挑架体对结构整体承载能力影响较小,建议施工时着重考虑压环和螺栓接口的局部破坏,适当增加锚固材料强度和锚固深度;悬挑架体设计时,若增大架体杆件连接材料强度,可适当增大钢管布置间距,提高钢管周转率,降低施工成本。

Based on the site conditions of the case, the safety performances of cantilever scaffold not fully standardized are designed, checked and calculated. Two models of structure simplification and refining are established by using the numerical analysis method. Firstly, the Midas Civil is used to calculate the stress condition at the connecting point of cantilever structure simplification model, and then, the refining model of welding line and bolt established by the plane element is used to check and calculate the safe bearing capacity of the cantilever detail structure. Finally, XTRACT is used to analyze the section of structural beam column, and the bearing capacity of the built structure is checked and calculated.Considering the wind loads, the proposed scheme meets the requirements of mechanical bearing capacity.The bearing capacity of each rod system and section steel is only about 30%. The performances of the other local materials cannot be fully used, except for the bolts, ear plates and welding lines, the utilization rate reaches about 70%. The cantilever frame has little influence on the overall bearing capacity of the structure. It is proposed that the local damage of press ring and bolt joints should be considered during construction. The anchoring material strength and anchoring depth are properly increased. During the design of cantilever frames if increasing the connecting material strength of frame member bars, the layout spacing of steel pipe can be properly increased to improve the turnover rate of steel pipe and reduce the construction cost.