钢筋混凝土框架柱端剪切破坏震害分析及对策

Mechanismanalysis and prevention of seismic shear failure of RC frame columns

摘要:

为避免钢筋混凝土框架柱在地震中因填充墙附加剪力导致剪切破坏，本文总结了近年来国内外破坏性地震中出现的典型柱端剪切破坏震害，采用ABAQUS对典型填充墙框架进行了水平推覆模拟，据此分析了框架柱端剪切破坏的受力机理，并以鲁甸地震中的一栋严重震损的实际结构为例，采用ABAQUS对典型填充墙框架进行了水平推覆模拟和受剪承载力计算.分析表明，填充墙附加剪力是造成框架柱端剪切破坏的主要原因.依据分析结果和已有试验成果给出了考虑填充墙附加剪力的柱端剪力荷载计算公式.震损结构案例分析表明，忽略填充墙附加剪力可能导致结构的抗倒塌能力严重下降，本文填充墙附加剪力公式计算结果与有限元分析结果及实际震害符合较好，可供工程设计参考.

Abstract:

To prevent reinforced concrete (RC) frame columns from seismic shear failure caused by additional shear force of the infill wall, severe shear failures of RC frame columns investigated in recent earthquakes were presented. Finite element modeling (FEM) pushover analysis with ABAQUS and mechanical characteristics analysis on 6 infilled RC frames were conducted. Then a RC frame structure subjected to LuDian Ms6.5 earthquake was analyzed by ABAQUS. The analysis indicates that the additional shear force of the infill wall results in the shear failure of the column. To ensure that a structure operates in a high-ductility mode, an estimation formula was developed for the additional shear force which could be used in structure design. The case study shows that without appropriate considerations about the additional shear force of the infill wall, anti-collapse capability of the structure will be threatened seriously. Analysis also demonstrates that the additional shear force estimation formula is in well accordance with the FEM analysis result and the seismic damage investigations, it can be a reference for engineering design.