人字支撑复合结构的合理耗能机制选择分析

THE PUSHOVER ANALYSIS AND OPTIMIZATION OF ENERGY DISSIPATION MECHANISM FOR CHEVRON BRACING COMPOUND STRUCTURE

通过对柔性梁柱加"人字"支撑形成的一榀新型复合结构进行静力弹塑性(Pushover)分析,从理论上研究该复合结构的抗震性能,满足按9度多遇地震的抗震能力和罕遇地震的抗倒塌验算。其耗能机制为"混合机制",塑性铰出现的位置及顺序为:支撑、梁端、柱下端、柱上端。为了得到更合理的抗震耗能机制,对影响复合结构耗能机制的主要因素、底层柱刚度和配筋、底层及二层支撑的配筋进行分析,由此优化出满足"强柱、中梁、弱支撑"多道防线抗震性能要求的合理耗能机制。计算结果表明,人字支撑复合结构的水平侧移表现为剪切变形。

Based on Pushover analysis, the new chevron bracing compound structure would be studied for seismic fortification properties. The compound structure satisfies seismic requirements of 9 seismic fortification intensity and anti-collapse of rare earthquake. The energy dissipation mechanism of the structure is belong to ＂mixed mechanism＂. The positions and orders of plastic hinges are braces, and then beams ends, at last columns ends. In order to obtain reasonable energy dissipation mechanism, it is analyzed the influence factors, such as section, steel areas of the braces for the first floor column, and steel areas of the braces for the first and second floors. A reasonable energy dissipation mechanism to satisfy seismic fortification properties of ＂stronger columns, medium beams, and week braces＂ is optimized. The analysis results indicate that the horizontal displacement of chevron bracing compound structure is a shear deformation.