极端荷载作用下公路桥梁荷载概率模型研究

我国桥梁设计规范中对极端荷载组合系数没有明确的规定，在以结构可靠度为基础的概率极限状态设计法中，由于公路桥梁各种作用比较多且大多随时间变化的范围比较大，各种作用的组合也比较复杂，所以必须选择合理的概率模型才能保证计算出真实合理的结构可靠度。通过查阅文献并结合WIM系统统计的车辆数据分析，建立了公路桥梁永久荷载及其效应概率分布模型；基于Matlab软件，在汽车车重总体服从多峰分布的基础上对实测数据进行训练拟合，建立了汽车荷载效应的概率模型并确定了汽车荷载分级加载方式，为公路桥梁可靠度研究和求解极端荷载组合系数奠定了基础。

Study on Load Probability Model of Highway Bridge under Extreme Load

In the bridge design code of China, there is no explicit provision on the extreme load combination coefficient. In the probabilistic limit state design method based on structural reliability, due to the fact that there are many kinds of functions of highway bridges and the most of change with time, the combination of various functions is relatively complex, and it is necessary to select a reasonable probability model to ensure that the true and reasonable structural reliability can be calculated. The probability distribution model of permanent load and effect of the highway bridge is established by consulting the literatures and combining with the vehicle data analysis of WIM system statistics; Based on the MATLAB software, on the basis that the overall vehicle weight obeys the multimodal distribution, the measured data are trained and fitted, the probability model of vehicle load effect is established, and the classification loading mode of vehicle load is determined, which lays a foundation for the reliability research of highway bridges and the solution of extreme load combination coefficient.