螺栓加强板对横隔板弧形切口的加固研究

INVESTIGATION ON REHABILITATION OF FLOOR BEAM ARC-CUTOUT BY USING BOLTED REINFORCEMENT PLATE

为研究螺栓加强板对横隔板弧形切口的加固作用,通过现场监测随机车流下加固前和加固后的弧形切口的应力响应,获得了加固前和加固后的弧形切口应力谱。基于等效损伤原则获得加固前、后弧形切口构造细节的等效应力幅和加载次数,结合AASHTO规范开展了加固前、后弧形切口构造细节的疲劳评价。研究表明:横隔板弧形切口主要受面内应力影响,螺栓加强板增加了横隔板的厚度,明显降低了弧形切口的应力水平,横隔板厚度过薄是导致该桥弧形切口疲劳开裂的原因,螺栓加强板可以改善弧形切口的疲劳性能。

In order to study the strengthening effect of bolted reinforcement plate for the floor beam arc-cutout at orthotropic steel bridge deck,the recorded stress time histories on the cutout were analyzed to obtain effective stress range and loading cycles,and finally to evaluate its fatigue performance based on AASHTO specification. It was found that the diaphragm cutout was controlled by the in-plane deformation,increasing the thickness of diaphragm could effectively reduce total stress,the thin diaphragm plate was an important reason for the high stress level at cutout. It was concluded that the bolted reinforcement plate could improve the fatigue performance of floorbeam cutout.