设防烈度8度(0.3g)区RC剪力墙结构抗震能力需求分析

实现RC剪力墙结构预期强震破坏模式的能力设计方法的不断改进，一直为工程师所关注。针对我国抗震设防烈度8度0.3g高烈度区RC剪力墙结构，设计了不同高度和整体性系数的结构模型，从而建立了预设延性破坏模式的分析模型。考虑大震变轴力对弯矩和剪力的影响，分析了剪力墙在大震作用的弯矩和剪力的实际需求沿结构高度的分布规律。结果表明，对于位于烈度8度0.3g区的剪力墙结构，考虑大震时轴力的变化对剪力墙受弯和受剪能力的需求影响较大；剪力墙的弯矩和剪力放大系数随结构的高度和整体性系数的增大而增大；现行规范规定的剪力墙受弯和受剪能力调整系数小于实际的需求，剪力墙中下部的弯矩和底部的剪力需求大，建议受弯能力调整沿高度采用三折线，提高剪力墙底部加强区的剪力放大系数或最小构造配筋率。

Seismic capacity demands of RC shear walls in Chinese seismic fortification intensity region 8(0.30g)

It is concerne widely by engineers to improve the capacity-based seismic design method of RC shear wall structures, a serials of RC shear wall structures with different structural heights and integrity factors were designed according to the current Chinese seismic design code for buildings in the regions of seismic fortification intensity 8 (SFI 8) with peak ground acceleration of 0.3g. Accordingly, analytical models with preset ductile failure modes were developed to investigate the distribution of shear and bending moment demands along building height under rare earthquake excitations. Especially, the influence of variable axial forces must be considered when studying the shear and flexural capacities. The results show that the variation of axial forces in shear wall structures under rare earthquake in the regions of SFI 8 (APG=0.3g) have much influence on their shear and flexural demands. The shear and bending moment amplification coefficients of shear walls increase with the increase of structural heights and integrity factors. The adjustment coefficients for shear and flexural demands of shear wall in the current design code are less than the real requirement, which makes a higher shear demand at the lower and bottom parts of shear wall structures. It’s suggested to adjust the flexural capacity along structural height in trilinear form, and to improve the shear amplification coefficient or minimum longitudinal reinforcement ratio in the strengthened portion at the bottom of shear walls.