Study On The Influence Of Vehicle Load Variation On The Reliability Of Bridges And The Improved Criteria Value Of Evaluated Load For Detection

With the continuous advance of industrialization and urbanization of the city in our country,the whole highway vehicle load have a large variation,the problem of vehicle overloading is becoming increasingly serious,real life of many bridges is far lower than the design life,leading to reliability of the existing bridge and the operating vehicle load variation problem has gradually become a hot spot of current research.Therefore,using the vehicle load of Jing-Zhu higjway,Yu-Zhan highway and Yue-Gan highway based on the obtained measured data,reproduce the random traffic flow of three highways,and using the GPD distribution calculate the reliability of existing bridges based on the proposed highway bridge detection and evaluation of improved load formula.The research work of this paper mainly includes the following four aspects:First of all,using dynamic weighing system WIM(Weight In Motion)to obtain the about three million vehicle load data for statistical analysis.Statistics on vehicle data according to weight,axle load and the wheelbase were classified,through the statistical analysis of the three highways,describes the characteristics of vehicle load,reflects the current operation status of highway vehicle load.Secondly,three high-speed traffic load data based on random traffic simulation by MonteCarlo method to calculate the beam loading effect of vehicle load,using the threshold model,maximum likelihood estimation theory,combined with the extreme value theory and probability theory,the construction of three high-speed highway traffic load effect in different residual maximum distribution function and service outside the extreme traffic load effect under the vehicle load effect analysis of different highway differences.Again,got the carrying capacity of existing bridges through the bridge detection method,combined with the extreme traffic load effect distribution so as to summarize the function of the bridge structure,used the Monte Carlo method to calculate the failure probability of the existing bridge function and considering the impact of vehicle load impact on bridge reliability,summarized the influence of the future development of bridge reliability by current reliability of bridge structure and vehicle load variation.Finally,according to the result of calculation,the highway bridge ' s detection and evaluation of improved formula of load value,and this formula as the design load of bridge reinforcement,inverse bridge reinforcement in the remaining service period for reliability at10 years,to verify the practicality of detection and evaluation of load.