钢筋混凝土框架带竖缝混凝土填充墙的抗震性能试验研究

Research on seismic performance of concrete slit infill walls in reinforced concrete frames

在钢筋混凝土框架中采用混凝土墙替代砌体填充墙,能够有效地提高填充墙的整体性,显著降低地震时由于砌体填充墙的破坏造成的人员伤亡和财产损失。但是由于框架填充墙的高宽比一般较小,采用混凝土填充墙极易发生脆性的剪切破坏。如果在墙体上预设竖缝,则有可能将其破坏模式转变为延性的弯曲破坏,从而减少墙体破坏。进行了4个试件的抗震性能试验,研究了竖缝形式、配筋率等参数对带竖缝混凝土填充墙的钢筋混凝土框架抗震性能影响。结果表明:设置竖缝能有效降低混凝土填充墙的抗侧刚度,并将其破坏模式由脆性的剪切破坏转化为延性的弯剪破坏,显著提高耗能性能和塑性变形能力,研究结果验证了这一设想的可行性。

In reinforced concrete frames,if monolithic concrete walls are used to replace masonry infill,better integrity and out-of-plane stability may be resulted,significant reduction in human life and property losses can be achieved as well.However,such a kind of concrete infill is usually squat,which is susceptible to brittle diagonal shear failure during earthquakes.Therefore,vertical slits are preformed in the wall web of the concrete infill to obtain slender wall piers,by which more ductile bending failure may be induced.Reversed cyclic loading tests of four specimens were carried out to investigate effect of such parameters as the pattern of slits,reinforcement ratio on their seismic behavior.The testing results have shown that preformation of slits on the concrete wall as infill in the reinforced concrete frame can effectively reduce the lateral stiffness of the infill.At the same time,the failure modes are shifted from the brittle shear failure to ductile bending shear failure,and the capacities of seismic energy consumption and plastic deformation are improved.Such a design philosophy has been verified by the experimental findings as a result.