摘要
通过现场交通调查获得车辆荷载谱,将车辆行驶时轮胎对桥面的作用看作瞬时的半正弦波冲击荷载。根据轮胎纵向接地压力的分布变化曲线推导了车辆动力放大系数理论公式,利用瞬态分析计算了不同车轴数车辆通过桥梁时的动力响应,得到箱梁内钢筋的循环轴向应力变化曲线。使用雨流计数法对钢筋循环轴向应力变化曲线进行分级,通过试验获得钢筋S-N曲线,并以线性累积损伤理论计算桥梁使用寿命。数值模拟结果表明:不考虑路面不平整度的情况下,动力放大系数在共振点之前,在零点附近上下波动;动力放大系数在共振点达到最大,之后随车速的增加而减小;正常允许交通载荷不会对桥梁寿命产生不利影响。
The vehicle load spectrum was obtained by using traffic survey. The forces of traveling vehicle tires on the ground could be taken as instantaneous half-sine impact loads. Based on the pressure distribution change curve in the longitudinal direction of tire on the ground, a theoretical formula of vehicle dynamic amplification factor（DAF） was deduced. Combining the transient analysis method, the dynamic response was calculated when vehicles with different axles passed through bridge, the cyclic axial stress curves of steel bars in box girder were achieved, and these curves were classified by using rain-flow counting method. S-N curve of steel bar was got through tests, and bridge service life was calculated by using linear cumulative damage theory. Numerical simulation result shows that without considering the roughness degree of pavement, dynamic amplification factor fluctuates near zero before resonance point, and it reaches the maximum at resonance point, then it decreases with the increase of speed. There are no adverse effects on bridge service life under non-overloading traffic. 3 tabs, 10 figs, 12 refs.
出处
《交通运输工程学报》
EI
CSCD
北大核心
2013年第6期20-27,共8页
Journal of Traffic and Transportation Engineering
基金
中国博士后科学基金项目(2013M540724)
陕西省交通科技项目(08-09K)
关键词
桥梁工程
车辆荷载谱
动力放大系数
S-N曲线
雨流计数法
bridge engineering
vehicle load spectrum
dynamic amplification factor
S-N curve
rain-flow counting method
作者简介
尹冠生（1958-），男，河北石家庄人，长安大学教授，工学博士，从事工程结构力学研究。
