钢筋网格加固铁路重力式桥墩振动特性研究

Research on vibration characteristics of railway gravity piers of rebar mesh reinforcement

据历年地震数据统计,桥梁震害大多集中在下部结构,尤其是在桥墩部位。外包混凝土、钢板和碳纤维布等传统加固方法虽能提高桥墩的强度,但其抗震延性相对不足且加固费用较高,很难做到大范围的防御性加固。本文提出一种采用钢筋网格加固铁路少筋混凝土桥墩的防御性抗震加固装置,以少筋混凝土重力式桥墩为工程背景,制作两个1/8的缩尺模型,并在其中一个模型墩底薄弱区进行植筋加固,水平向输入El-Centro波进行振动台试验研究。试验结果表明:加固墩在强震作用下墩顶位移减小,墩顶加速度增大,墩底应变减小,其开裂截面仍然在墩底,主要破坏裂缝并没有向上转移,说明钢筋网格加固墩具有良好的抗震性能。

According to the statistics of earthquake data over the years,most of the damage to bridges is concentrated in the substructure,especially at the piers.Considering that such traditional reinforcement methods as concrete,steel plate and carbon fiber sheet,can improve the strength of piers,but the seismic ductility is relatively insufficient,with high reinforcement cost,so it is difficult to achieve defensive reinforcement on a large scale.A defensive seismic reinforcement device for railway,less reinforced concrete piers using rebar mesh reinforcement,is proposed,and two 1/8 scaled models are made with the less reinforced concrete gravity piers as the engineering background,and a reinforcement of planting reinforcement is carried out in the weak area of the bottom of one of the model piers,and the horizontal input El-Centro wave is subjected to shaker test research.The results show that,under the action of strong earthquake,the displacement of the pier top decreases,the acceleration of the pier top increases,the strain of the pier bottom decreases,and its cracking section is still at the bottom of the pier,and the main damage crack is not transferred upward,indicating that the rebar mesh reinforcement piers have good seismic performance.