Reliability Analysis Based Permit Checking Of Overloading Vehicles On Bridges

Overloading transportation is very important to the development of the nationaleconomy, but overloading vehicles can cause structural damage to bridges along theroute，which may affect the good’s normal transportation, and reduce the safetyservice life of the bridge greatly. Nowadays, China’s road administrative departmentexamine and approve for overloading vehicle by two methods. One is time-consumingstructural internal force analysis, and another one is simply manual judged based onthe experiences. However, these two methods are low efficiency. Therefore, set up asafe, reliable, simple and practical evaluation criteria is great significant for checkingthe overloading vehicles permit quickly. The mainly research work of this thesis canbe summarized as following three aspects:(1) Based on the theory of probability and statistics, this paper established theprobability model of typical5-axle and6-axle overloading vehicles load in GuangXiautonomous region, mainly including the bimodal normal distribution model of totalweight, the linear regression model of total weight and axle weight and the lognormaldistribution model of wheelbase L3, etc. And the paper also established vehicle loaddatabase by overloading vehicles randomly generated by Monte Carlo method.(2) Introduce the calculation principle of using reliability index method foroverloading vehicles permit checking detailed. A comparative study on the calculationresults of overloading vehicles permit checking by three methods, including the loadeffect comparison method, the equivalent load distribution method and the reliabilityindex method, which presented to verify the feasibility of the reliability indexmethod.(3) Based on the reliability index methods, this paper established a weight limitcriterion for5-axle and6-axle overloading vehicles cross simple supported slabbridges and T girder bridges in GuangXi autonomous region. And the paper alsoprovided the maximum permissible weight limit criteria table and the envelopemethod for overloading vehicles permit checking under each different design loadlevel. It verified the feasibility of checking the overload vehicles permit according tothis paper’s provisions, through a comparative study on the calculation results of theactual overloading vehicles permit checking by the weight limit criterion and the reliability index method.