基于桥面不平度的车辆动载对铺装层应力的影响研究

Dynamic Response of concrete bridge deck pavement with roughness under vehicle-bridge-deck pavement coupling effect

摘要:

为了研究混凝土桥梁在车辆随机动载作用下,桥面不平整度对铺装层控制应力响应的影响规律,采用具有典型性的双自由度1/4车辆模型,考虑车轮的随机动载作用,建立车—桥—铺装层耦合振动的实体模型,研究了铺装层不平整度以及车速变化时,铺装层控制应力的变化规律。结果表明：铺装层的应力极值响应相比于跨中节点的应力时程响应,不仅可以反映车辆荷载的随机性,还能够抓住结构最不利响应；同一不平整度下,铺装层内各项控制应力的极值响应曲线峰值的放大系数非常接近；当桥面平顺性一般及较差时,铺装层各项控制应力的极值相比于桥面绝对平顺时增大了1倍多。通过对桥面铺装平整度进行测量和评估,可一定程度上把握铺装各项控制应力的变化情况,可较为直观和方便的实现对铺装层的检测评估。

关键词:桥梁工程;桥面铺装;有限元分析;车辆随机荷载;桥面不平整度

Abstract:

In order to study the effect law of deck pavement roughness on dynamic response of concrete bridge deck pavement under vehicle random load, vehicle dynamic load was simulated by MATLAB software based on 2-DOF 1/4vehicle model and then applied to 3-D finite entity model of vehicle-bridge-deck pavement coupling vibration through ANSYS software. The results shows that: compared with stress time-history response of a fixed node, the response of extreme value of pavement stress can not only reflect the random character of vehicle load but obtain the most unfavorable response of pavement; at a certain roughness, the magnification coefficient of different stresses are very similar and when deck pavement is uneven, the extreme value of pavement stress are more than one time larger than absolutely smooth pavement; if a set of complete and accurate assessment criteria could be developed for bridge deck pavement, the stress state of deck pavement could be controlled from a macroscopic perspective by monitoring surface roughness.

Key words:Bridge engineering; bridge deck pavement; finite element analysis; vehicle random load; deck pavement roughness