Study On Lane Longitudinal Reduction Factors Based On Reliability Theory And Surveying Traffic Loading Data

Combined with newly measured vehicle loading data and based on reliability theory, the paper statistically analyzed the response ratio for the virtual beams under the loading from measured and the national designing code. According to the statistical ratio, longitudinal reduction factors can be obtained for highway bridges.Based on theory for the virtual beam, a parallel computing code package, a LLRFS (Lane Longitudinal Reduction Factor System), was developed by using MATLAB and VBA compilers in the paper. LLRFS is used to process the traffic load data collected on multiple typical measuring station. Those traffic load from one typical lane can be treated as a random process and a natural vehicle group which was provided for the LLRFS to calculate the key response of some controlling sections for virtual simple-supported beam and continous beam with different spans. According to the National Code, a design response can also be obtained for those virtual beams. The response ratio can be computd from the testing and design response. It assumes that the calculation of the probabilities of these random effects distribution of normal distribution, lognormal distribution, exponential distribution, extreme value distribution of type I, Rayleigh distribution, gamma distribution, and Weibull distribution, Poisson distribution, using k-s test assumes that the probability distribution of the test. Get discount coefficient of longitudinal statistical value, main research include:(1) The paper introduced the basic theory of reliability and deduced theoretical calculation formula for loading on virtual beams. Moreover, a VBA source code has developed to dealing with the huge measuring traffic load data. Basic batch data files have been produced by the VBA code for longitudinal reduction factors analysing.(2) Virtual simple-supported beams and continuous beams have been selected with spans for50m,100m,150m,200m,300m,400m,600m,800m,1000m,1250m, and1500m. The virtual continous beams have three spans with the ratio of side spans to the mid-span for0.5,0.6,0.7, and0.8. With the parallel calculation program, LLRFS, the controlling response ratio for the virtual beams can be obtained under the measured traffic loading and the loading from the national code, respectively. Thus, the longitudinal reduction facts can be obtained for overloading and normal loading specified by the national code. (3) By fitting the longitudinal reduction factors, two calculation formula have built for overloading and overloading and normal loading specified by the national code, respectively.Results show that longitudinal reduction factors have the same trend with code BS5400for the United Kingdom without overloading. Overloading has great impact on the longitudinal reduction factors when the bridge main span is less than400metres. Overloading case double its longitudinal reduction factor to non-overloading case. Therefore, overloading must be strictly restricted.