钢筋混凝土柱地震破坏模式及考虑剪切变形的抗震性能研究进展

State of the art of seismic performance including shear effects and failure modes of reinforced concrete columns

强震作用下钢筋混凝土(RC)柱如果设计不合理、抗剪措施不当或缺乏必要的抗震构造等会发生低延性的弯剪或剪切破坏,进而引发结构发生局部或整体倒塌,造成重大损失。为研究弯剪和剪切型RC构件的地震损伤机理和抗震性能,总结了RC柱的主要地震破坏模式、破坏模式判别方法以及剪切变形对柱抗震性能影响的研究进展。结果表明:RC柱的地震破坏模式主要有弯曲、剪切及弯剪型三种,其中弯剪破坏模式的界定和判别是研究的难点和重点;剪切变形对弯剪型RC柱抗震性能的影响主要体现在塑性变形阶段,但定量分析该影响的方法目前仍以经验模型为主,缺乏相对统一的力学模型。此外,已有的相关研究忽略了复杂的地震作用(即往复荷载作用历史)对柱破坏模式和损伤特性的影响,这需要在今后的研究中予以重点关注。

Reinforced concrete （RC） columns with unreasonable design, weak shear capacity and poor seismic details are vulnerable to flexure-shear failure or shear failure during earthquakes, which is prone to locally and totally collapse of structures and great losses. To further study the damage mechanism and seismic performance of shear-critical RC members, the research progresses on seismic failure modes, classification methods, and seismic performance considering shear effects for RC columns were presented. The results indicate that the seismic failure modes of RC columns can be categorized into flexure, shear and flexure-shear, but the failure mode of flexure-shear is difficult to judge precisely and often focused on by researchers in the seismic study and design. The shear effects on the seismic performance of shear-critical RC columns are mainly reflected in the plastic deformation stage, but the available methods for quantitative analysis of the shear effects are mainly depended on empirical models, and the generally accepted mechanical model for this problem is still need to study deeply. Moreover, the influences of the complex seismic loading （ i. e. the history of cyclic loading） on the failure modes and damage characteristics of RC columns are mostly ignored in the previous studies and need to be investigated in-deepth in the future.