低烈度区低配筋多层剪力墙结构抗震性能分析

Seismic performance analysis of low reinforcement shear wall structures in low-intensity regions

为研究低烈度区多层剪力墙结构采用比现行规范规定偏低配筋时的抗震性能和工程应用可能性,针对4种不同平面布置形式的多层剪力墙结构,依据现行结构设计规范,分别按抗震设防烈度6度、7度(0.10g和0.15g)进行抗震设计,并减少结构设计规范要求的墙身构造钢筋量,形成低配筋多层剪力墙结构。经对设计完成的相同平面布置的低配筋剪力墙结构的截面和配筋情况进行对比,发现6度和7度(0.10g)设防区的构件截面和配筋完全相同,而与7度(0.15g)设防区稍有差别。采用Perform-3D程序对设防烈度7度区低配筋多层剪力墙结构进行非线性动力反应分析,结果表明:结构在7度罕遇地震作用下的地震反应很小,进入非线性的区域不大,结构损伤轻微;对比墙身配筋率显著小于低配筋多层剪力墙结构的剪力墙试件试验结果发现,在7度罕遇地震作用下,低配筋多层剪力墙结构中剪力墙的损伤很小,且最大层间位移角远小于其极限位移角。因此,低配筋多层剪力墙结构的抗震性能良好,可以在低烈度抗震设防区(6度和7度区)采用。另外,根据分析结果,建议墙体水平和竖向分布钢筋配筋率分别为0.15%和0.10%。

To find out the seismic performance and the possibility of engineering application of multi-story shear wall structures with lower reinforcement in low-intensity regions, compared with the specification of the current codes, twelve multi-story shear wall structures with low reinforcement in intensity zone 6, 7 （0. 10g） and 7 （0. 15g） were respectively designed as low reinforcement shear wall structures. It was found that the structures in intensity zones 6 and 7 （0. 10g） had exactly the same floor plan but slightly different form that in intensity zone 7 （0. 15g）. According to the result of the nonlinear time history analysis by perform-3D, under the input of rare strong motion records corresponding to intensity zone 7, the seismic responses of the structures are small and little nonlinear, and the damage to the structures is relatively slight, most of which appear at the ends of coupling beams instead of shear walls. Comparing the experimental results of the shear walls with much lower reinforcement ratio of distributed steel bars with the results of the shear walls with low reinforcement, it is found that not only the ultimate drift ratios of the low reinforcement shear wall specimens are much larger than the maximum inter-story drift ratio with 84% guaranteed rate, but also that the damage to the walls is very slight corresponding to the maximum inter-story drift ratio. Therefore multi-story shear wall structures with low reinforcement will behave well under strong earthquake and can be applied in low intensity zone （intensity zones 6 and 7 ） as long as they have been designed well. It＇s suggested that the distributed horizontal and vertical reinforcement ratios should be 0. 15% and 0. 10% respectively.