The Permit Management and Safety Assessment of Shengli Bridge under Overweight Vehicle

With the development of transportation industry, the number of times that overloaded vehicle pass through bridges increases day by day. Taking Shengli bridge as an example, the bridge model was established with finite element software in this paper. According to the vehicle parameters, the vehicle loading model was abstracted, and the process that overloaded vehicle pass through the bridge was simulated. Finally, the safety margin of the bridge was evaluated on the basis of bearing capacity analysis. Permit management measures for the bridge were proposed, which can be referenced by relevant situation. Keywords-permit management; bridge; safety; assessment; overweight vehicle I. RESEARCH INTRODUCTION Recently, the demand of national defensive modernization and development of modernistic industry, the industrial equipment of metallurgy, petrochemical and electrical factory which are made in china or imported from other counties have the tendency of large-scale, the device in construction of mine engineering and electrical station usually are not permitted to decompose. The transporting tools which carry the large scale cargo have developed rapidly. The transporting capacity has been up to 1000 t [1]. Due to the lower design load-rate, same original bridges can not safely carry the present traffic load which increased explosively during several decades. At the same time, there are some hidden dangers and problems in the existing bridges with the aging of them. While bridges is the key part of highway line, which load bearing capacity and transporting capacity is essential for the large scale cargo transportation. It is very critical for large scale cargo transportation that the bridge have enough potential resistant capacity. With the economy development, it is inevitable to transport the overweight vehicle pass through bridges. Therefore, the permit management and safety assessment of bridge under overweight vehicle have become particularly prominent. In order to assure the safety of bridges, many researches about overweight transportation have carried out for several years. Gindy, M presents the development of an automated system which offers several benefits including significant time and cost savings and improved customers service to motor carriers in the Rhode Island Department of Transportation [2]. Schulz, J.L. proposed field test procedures consisted of performing diagnostic load tests on each structure type as it was subjected to both a standard vehicle load and then an overload vehicle. Finite element models (FEM) were developed and an analysis performed with the same loads as those applied in the field. Comparisons between the measured strains and the analytical strains were made, and each model systematically modified until comparisons were in good agreement. At last whether the results is overor underconservative in predicting maximum stresses is evaluated [3]. Ravn, D.L. induced the permit system of overweight vehicle used in Denmark. Two different methods for bridge rating are described in that paper. One system is based on a bridge rating concept where the major bridge is considered as a number of "bridges within the bridge" and compared with the actual vehicle classes. Bridge classes are calculated for each "bridge within the bridge". The other system is based on a concept where bridge elements, with the highest utility ratio are checked for each individual transport by means of a computer program with tabulated load effects and influence lines for determination of load effects from heavy transports [4]. Vigh, Attila presents a method for comparing the mechanical effects of overweight and design load vehicles on bridges. There is no restriction on the arrangement of the axles and on the size of the axle loads. The bridge may be a simple span bridge, a continuous girder, a truss girder, or an arch. Even for a very complex bridge structure the only required parameter of the bridge is the span length. The presented method is a robust and reliable tool for the permitting process of overweight vehicles, which is verified by several thousand comparisons [5],[6]. Osegueda, Roberto document the development of an automatic procedure for the routing of overweight vehicles with load-carrying and vertical clearance restrictions for the bridges of a highway network. The use of a network routing procedure within a geographic information system (GIS) 978-1-4244-4639-1/09/$25.00 ©2009 IEEE operating in a PC environment is one of the distinctive features of the proposed approach. The procedure automatically identifies all bridges on a specified route and evaluates the adequacy of the bridge structures as well as vertical and horizontal clearance requirements for a given vehicle. A GIS computerized support methodology consistent with the Texas Administrative Code is developed. In particular, the proposed approach uses bridge load formulas to evaluate the adequacy of bridge structures for incoming overloads. Sample runs of the procedure using Texas data indicate that the procedure is computationally efficient [7]. Yang Hongjian figure out the bridge’s bearing capacity based on the actual strength of material and the construction’s characteristics, and develop an accurate evaluating methodology to guide computer program on the safety issues of bridge [8]. Zhao yu presents some evaluation steps, check calculation methods, calculation principles and pass management measures when the overweight vehicle pass through the bridge. At the same time, some usual reinforcement measures under overweight vehicle are given in order to ensure the safety of the bridge[9]. Zong Xuemei puts forward the fuzzy comprehensive evaluation method for checking parameters Z1 of carrying capacity of existing bridges, and the method is tested by an example[10]. I