基于WIM的广东省公路桥梁车辆荷载模型研究

Research of Vehicle Load Model for Highway Bridges in Guangdong Province Based on WIM Data

为研究适合于广东省实际的公路桥梁车辆荷载模型,选取该省5条具有代表性的高速公路,基于动态称重(WIM)系统实测的交通轴载数据,参照《公路钢筋混凝土及预应力混凝土桥涵设计规范》(JTJ 023-85)的方法,拟定符合广东省实际交通状况的车辆荷载参数,获得相应车辆荷载模型,并采用推荐车辆荷载模型与规范荷载模型对不同结构形式的桥梁活载效应进行对比分析。分析结果表明,按照规范原则得到的广东省实测车辆荷载总重和轴重均大于规范给定值;各种结构桥梁在推荐的车辆荷载模型作用下的活荷载效应均为规范计算值的1.4倍左右,桥梁跨径越小,活载所占设计荷载的比例越大,规范对活载效应的低估越明显。

To research the vehicle load model that is suitable for the highway bridges in Guangdong Provinee, 5 typical expressways in the province are selected. Based on the traffic axial load data measured by the weight-in-motion （WIM） system and with reference to the methods as provided in the Chinese code （JTJ 023-85）, the vehicle load parameters that conform to the actual traffic conditions in the province are worked out, the corresponding vehicle load model is acquired and the live load effect of the bridges of different structural types are comparatively analyzed, u- sing the acquired model and the vehicle load model in the code. The results of the analysis show that the total weight and axial weight of the vehicle loads of the bridges in the province measured by.the model acquired according to the principles of the code are greater than the values of the to- tal weight and axial weight given in the code. The live load effect of the bridges of different struc- tural types under the action of the acquired vehicle load model is about 1.4 times the ealeulated values of the live load effect in thee code. The smaller the span length of a bridge is, the greater the proportion of the live load accounting for the designed load is and the more notable the under- estimation of the live load effect in the code also is.