RC剪力墙结构小震与中震设计对比及其抗震性能研究

近年来,国内学者强调对于复杂和超限结构需进行中震性能设计,即在小震弹性设计后进行中震下的承载力复核及调整,然而中震设计能否提高结构整体抗震性能仍存在争议。为探究中震设计与小震设计方法的差异,本文依据现行规范,以设防烈度、结构高度和场地类别为变化参数,建立了48个典型RC剪力墙模型,并分别以“小震”、“高规中震”、“广东高规中震”和“关键构件中震”进行截面设计,之后进行罕遇地震作用下的弹塑性分析及增量动力分析计算。在对比了不同设计方法的钢筋用量、结构与构件性能表现及结构抗倒塌能力储备的差异后认为,现行中震设计方法存在诸多弊端,包括会导致结构用钢量的显著增大,结构延性的降低,及结构安全度的降低等;采用关键构件中震设计方法则能较好地提高结构整体抗震性能,更符合抗震设计概念。因此,建议对RC剪力墙结构仅针对关键构件进行中震性能设计,以提高重要结构的安全性。

Comparative study on seismic design under frequent earthquake and moderate earthquake and seismic performance of RC shear wall structures

In recent years,moderate earthquake performance design methods have been stressed to carried on complex and out-of-gauge structures,that is,to review and adjust the bearing capacity after frequent earthquake elastic design.However,whether moderate earthquake design can improve the seismic performance of structures is still controversial.To compare the differences between these two design methods,48 typical RC shear wall structures have been established with different fortification intensity,structural height and site category,and then have been designed with“frequent earthquake design”,“moderate earthquake design of JGJ 3-2010”,“moderate earthquake design of DBJ 15-92-2013”and“moderate earthquake design of key element”respectively.Afterwards,the elastic-plastic analysis under rare earthquake and incremental dynamic analysis have been conducted.After the comparison from the aspects of the amount of reinforcement,the performance of structures and elements under rare earthquakes,and the anti-collapse reserve capacity of structures,this paper holds that the current moderate earthquake design method can lead to the increase of steel consumption,the decrease of structural ductility,the decrease of anti-collapse safety factor and so on,while the moderate earthquake design of key element can improve the overall seismic performance of the structure,and more in line with the concept of seismic design.Therefore,moderate earthquake design of key element is suggested for RC shear wall structure to improve the safety factor of important structures.