功能可恢复RC框架-核心筒结构抗震性能研究

功能可恢复结构既能在地震中保障人们的生命财产安全,又能使得建筑在地震后尽快恢复正常功能,是基于性能抗震设计方法的研究热点和未来的发展趋势。合理地对剪力墙结构或者框架-剪力墙(核心筒)结构中的连梁进行设计或者使用高性能构件是实现该类建筑震后功能可恢复的有效途径之一。建立了一典型RC框架-核心筒结构的弹塑性分析模型,比较了连梁不同恢复力性能参数下RC框架-核心筒结构抗震性能的差异,研究实现整体结构功能可恢复目标时对连梁性能参数的需求,并且探索使用轻质楼盖结构体系后抗震性能的改变。研究结果表明:若将连梁设计承载力提高10%~30%,则模型整体的峰值承载力提高约3%~8%,罕遇地震作用下连梁损伤程度相比原始模型减小、墙肢损伤程度增大;若将连梁骨架曲线中的平台段长度或者屈服后的硬化段长度延伸,则模型整体的承载力提高,结构推覆曲线下降趋势更为平缓,新模型虽然在罕遇地震作用下结构的损伤状态没有明显改善,但在超越设防烈度的地震作用下的抗倒塌能力得到了提高;若将楼盖结构体系的质量减小约35%,则模型一阶周期减小约4%,大震下结构基底剪力减小约5%,结构抵抗大震的能力降低不明显,且竖向构件轴压力减小,构件延性提升,结构的抗震性能有所改善。

Study on seismic performance of earthquake resilient RC frame-core tube structures

Earthquake resilient structures which can protect life and property safety from seismic hazard and restore structural function rapidly, are concentrated studying fields and future development trends in performance based seismic design method. For shear wall structures or frame-shear wall(core tube) structures, designing coupling beams reasonably or employing high-performance components is one of the effective ways to fulfill the earthquake resilient structures. The elasto-plastic analysis model of a typical RC frame-core tube structure was constructed. The differences in seismic performances of the models with different coupling beam hysteretic characteristic parameters were compared. The demand on capacity of coupling beams to restore the structure function and the influence of application of light self-weight floor system on seismic performance were studied. The research results indicate that: if the design bearing capacity of coupling beams is raised by 10%~30%, the structural peak bearing capacity increases by 3%~8%. The damage of the coupling beams becomes slighter and that of wall piers becomes severer under rare earthquake action. If the length of horizontal part or ascending part of the coupling beam skeleton curve is elongated, the structural bearing capacity increases, the descending segment slope of the structural pushover curve becomes flatter. Although the structural damage has no obvious improvement, the capacity to prevent structure from collapsing against rare earthquake excitation is raised. If the self-weight of the floor system is reduced by 35%, the fundamental period decreases by about 4% and the base seismic force decreases by about 5% under rare earthquake, there is no significant effect on the bearing capacity, axial force of vertical members decreases, ductility of members is improved, and the structure seismic performance is enhanced.