钢筋混凝土桥墩地震破坏振动台试验研究

钢筋混凝土桥墩箍筋约束不足和剪跨比过小(短柱)造成的脆性剪切破坏在近几次地震桥梁震害中占有较大比重.为解决此问题设计制作了各3根圆形截面和方形截面桥墩试件,分别代表具有良好箍筋约束、配箍率不足和小剪跨比3种情况,并通过振动台试验研究了其抗震性能.对小震、中震和大震作用下桥墩试件的破坏形态、加速度和位移反应、位移延性系数和耗能等方面进行了比较分析,结果表明,小剪跨比桥墩在地震作用下反应位移延性系数较大,在抗震设计时应引起足够重视.

Experimental study of seismic damage of reinforced concrete bridge piers on shaking table

In the recent destructive earthquakes, brittle shear failure of reinforcement concrete bridge piers with low lateral reinforcement ratio or with low shear span ratio accounted for quite a few reasons in the bridge failure cases. 6 reinforced concrete bridge pier specimens, 3 circular-sectioned and 3 square-sectioned, which represented bridge piers with sufficient lateral reinforcement ratio, with low lateral reinforcement ratio and with low shear span ratio respectively, were tested on the shaking table and the seismic performances were studied. The damage states, acceleration response, displacement response, displacement ductility factors and energy dissipation of the specimens when they were subjected to minor-magnitude earthquake, medium-magnitude earthquake and large-magnitude earthquake were analyzed and compared. The experimental results show that the displacement response ductility factor of low-shear-span-ratio bridge piers is large, which should be paid much attention to in the seismic design.