Reinforcement Solution Of Fasting Stone Arch Bridge And Bearing Capacity Evaluation

Since traffic flow and vehicle load increased year by year, the early stone bridges are in overload condition with various forms of diseases. As an important coal channels in Shanxi, the traffic of national road G208 was too busy to reasonable load. Overloading of the bridge using function and safety function brought serious hidden dangers, so detect and reinforce the damaged bridges has important practical significance.A case on the reinforcement solution of a fasting stone arch bridge of the G208 in Shanxi coal channel, the main diseases, strengthening plan were analyzed. Based on the finite element method, the mechanics was analyzed before and after bridge reinforcement. According to the measured traffic for 24 hours after reinforcement, bridge bearing capacity was evaluated. The main contents were focused on three aspects. First, the paper analyzed the disease of bridge, and determined the internal and external causes, then argued the corresponding reinforcement design scheme. Second, based on the FE analysis software MIDAS, a bridge finite element model was established, before simulation analysis of the reinforcement at various stages. Then the displacement values of the bridge structure under temperature and influence of live load were given. The paper compared the weight, temperature load and heavy truck loads of structural stress between three hinged arch and two hinged arch. Third, the paper gave the comparison between China and the United States in the differences of bridge bearing capacity evaluation method. In the end, bearing capacity was evaluated from traffic flow data.The study suggests that the internal reason of the phenomenon down-warping dislocation in a spandrel-braced stone arch bridge is that the arch hinge fragile, and the external reason is that the overload is too serious, and the effect of low temperature in winter. Based on the above two reasons, this article put forward to increase the vertical wall cross section, two hinged arch, instead of three hinged arch for thickening of arch ring, replace soffit expansion joint structure measures, such as the finite element analysis to verify the scheme is effective. In addition, this paper studied the bridge three hinged arch crown hinge functionality is basic failure, arch ring of arch constraint ability is poorer, when heavy vehicle action, vault down-warping. Traffic survey data confirmed the main conclusions in this paper. Through continuous 24 hours of traffic flow survey found that the speed of statistical regularity conforms to normal distribution, basic meet gamma distribution statistical regularity of vehicle weight. Through calculation, the strengthening of bridges quartile and arch section carrying capacity meet the requirements.