S2型电缆桥架地震应力快速预估方法

The Quick Method for the Prediction of the S2 Type Cable Tray Supports Stress under Seismic Loads

为了给出能够快速、即时地预估S2型电缆桥架的应力方法,根据电缆桥架的结构特点将S2型支架振动问题简化为端部带质点的悬臂梁振动模型,以质量点的大小和在悬臂梁的位置,研究其对悬臂梁的参与系数、振型等影响。研究结果表明,端部点质量点的悬臂梁适用于预估电缆桥架的自振频率、弯曲应力等,并与反应谱分析方法和抗震鉴定试验结果进行了比较,结果相吻合;端部带质点的悬臂梁模型能够表征S2型支架振动情况,其能够满足S2型电缆桥架的即时预估,为项目现场设计人员提供经验支持,快速给出设计意见,亦可作为初步设计依据。

Although cable tray supports are simple in structure,their seismic analysis calculations are still time-consuming.In order to get an assessment method that can evaluate cable bridges quickly and instantaneously,this study simplifies the S2 type supports vibration problem into a cantilever beam vibration model with mass points at the end.According to the structural characteristics of the supports,we investigates its influence on the participation coefficient and vibration pattern of the cantilever beam in terms of the size and position of the mass points in the cantilever beam.The results show that the cantilever beam with mass point at the end is suitable for assessing the self-vibration frequency and bending stress of the cable bridge,and the results are compared with the reaction spectrum analysis method and the seismic identification test results,and the results are in good agreement.The cantilever beam model with mass points at the end can characterize the vibration of type S2 supports,which can meet the immediate assessment of type S2 cable supports,provide empirical support for project site designers,give quick design advice,and can also be used as a basis for preliminary design.