不等跨布置RC空间梁-板结构竖向倒塌能力数值研究

为研究不等跨布置下RC空间梁-板结构抗连续倒塌能力,利用有限元软件ABAQUS建立在关键柱失效下空间框架结构精细化模型,通过Pushdown分析方法对试验子结构进行数值模拟。分析关键柱失效位置、梁板参数、楼板的损伤性能以及梁端截面内力对倒塌能力的影响。分析结果显示:内柱失效工况下楼板能提供承载力的40%~50%,边柱失效工况下楼板能提供20%~30%的承载力,角柱失效工况下楼板能提供15%~25%的承载力;梁跨度越大,柱失效后结构承载力越低,等跨设计的结构较不等跨设计受力存在“滞后性”,且横向约束对无板结构承载力基本上没有影响;梁板参数对提高结构承载力以及延性有重要影响;小变形下楼板损伤性能可以反映楼板的屈服模式,从而可推测楼板裂缝分布;最后提出了不等跨布置下考虑楼板影响的承载力计算公式。

Strengthening of Concrete Box Girder Bridges under Close-in Detonations

The response of a bridge superstructure under blast loading might depend largely on the extent of the local damage experienced due to close-in explosion threats. This paper investigates the local and structural response of box girder bridge decks strengthened using CFRP （carbon fiber reinforced polymers） under close-in detonations. Due to the lack of experimental research on this topic, the study is conducted using the explicit finite element computer program LS-DY-NA. The numerical study will be verified using the results of strengthened reinforced concrete slabs under field detonations. The blast load was assumed to be detonated above the bridge deck. The key parameters investigated are the charge size, and the strengthening location on the deck. This paper will present the results of this investigation and provides recommendations for predicting the local damage level based on the CFRP strengthening design under blast threat.

武汉某超限高层住宅结构抗震分析设计

武汉某住宅超限高层项目结构高度138.3m,采用框架-剪力墙结构形式,剪力墙为钢筋混凝土剪力墙,框架柱为钢管混凝土柱,属于B级高度建筑,存在扭转不规则、凹凸不规则、穿层柱等多项不规则项。利用YJK、MIDAS Builiding、SAUSAGE等计算软件对结构进行小震弹性分析、小震弹性时程分析、中大震等效弹性分析、大震弹塑性时程分析,并补充了弱连接处楼板抗震性能化设计以及穿层柱屈曲分析。计算结果满足规范要求,可供同类工程设计参考。