某轨道交通走行面伸缩缝预埋件加固性能试验研究

Experimental Study on Reinforcement Performance of Expansion Joint in Track Beam of a Rail Transit Project

某轨道交通走行面伸缩缝两侧的预埋件在车辆运行过程中出现个别松动现象,预埋件处混凝土局部开裂压碎,给车辆运行带来安全隐患。本文在损伤调查及分析预埋件受力状态和损伤机理基础上,提出了加固处理方案,并进行了3个足尺伸缩缝预埋件节点试件的疲劳试验,对比研究了植筋塞焊固定钢板和化学锚栓固定钢板的加固效果。试验结果表明:植筋塞焊固定钢板和化学锚栓固定钢板均有较好的加固效果,且化学锚栓固定钢板加固试件的刚度优于植筋塞焊固定钢板的加固试件;3种工况试验试件的疲劳寿命均大于300万次,化学锚栓固定钢板加固试件的疲劳寿命甚至大于1000万次。本文提出的加固方法和研发的无机胶黏剂对于类似工程和提高钢筋混凝土后锚固节点承载力具有推广价值。

The embedded parts on both sides of the expansion joint of a rail transit surface are loose in the process of vehicle operation.The concrete at the embedded parts is cracked or even crushed,which brings safety risks to the operation of the vehicle.Based on the damage investigation,the paper analyzes the stress state and damage mechanism of the embedded parts,puts forward the reinforcement treatment scheme,and carries out the fatigue test of three full-scale joint reinforcement specimens,and compares the reinforcement effect of the steel plate fixed by plug welding with the bonded rebars and the chemical anchor bolt.The results show that,the steel plate with chemical anchor bolt and plug welding has better reinforcement effect,and the rigidity of the chemical anchor bolt fixation steel plate is better than that of the steel plate reinforced by plug welding;the fatigue life of the three working conditions is more than 3 million times,and the fatigue life of the chemical anchor bolt fixed steel plate is even more than 10 million times.The reinforcement method and inorganic adhesive developed in this paper are of great value for similar projects and for improving the bearing capacity of post-installed joint with reinforced concrete.