支座沉降对大跨度钢结构连廊地震受力性能影响分析

在大跨度钢结构连廊的地震冲击影响分析中支座沉降都被忽略,而分析其受力情况对抗震性影响至关重要。研究支座沉降对大跨度钢结构连廊在地震中的受力性能变化,建立连廊结构在地震中的受力模型。做法为模型设定一个沉降量,计算支座沉降时,在地震冲击下连廊(包括钢框架和钢桁架)附加内力,再利用结构力学方法得到连廊附加弯矩图,得出沉降量对连廊钢框架地震冲击表达式,利用SAP2000软件分析不同沉降量下连廊钢桁架结构内力变化情况,得到连廊上、下弦杆在地震作用下的最大弯矩和最大轴拉力。实验结果表明,计算得到支座沉降后,连廊上弦杆和腹杆内动力系数最大值分别为0.17、0.15,比传统的时程分析法更接近相关规定值0.16,结果准确。

Influence of Support Settlement on the Seismic Behaviorof Large-span Steel Structure Corridors

The influence of support settlement on the seismic impact analysis of long-span steel structure corridors is often overlooked, but is very important. In this paper, such an influence was studied, and a stress model of the long-span steel structure in earthquakes was established. Incorporating settlement amount into the model, the additional internal force of the corridor (including steel frame and steel truss) under earthquake impact was calculated. The additional bending moment diagram of the corridor was then drawn using structural mechanics, and the seismic impact expression of the settlement on the steel frame of the connecting corridor was obtained. The internal force change of the steel truss structure connected with the corridor under different settlement levels was analyzed with SAP2000 software. The maximum bending moment and maximum axial tension of the upper and bottom chords on the corridor were then calculated under earthquake conditions. The experimental results showed that after support settlement, the maximum dynamic coefficients of the upper chord and web member were 0.17 and 0.15, respectively, which was closer to the relative code value (0.16) than the results achieved through the traditional time-history analysis method.