Reliability Analysis Of Strengthened Small Bridge In Highway

In order to adapt to the requirement of development of transportation and guarantee the safe using of existing RC bridge in highway, it is necessary to assess load-resist ability of existing RC bridge comprehensively by load test and calculation for serious damaged bridge or latent damaged bridge, determine the using condition or strengthened measure. After consolidation, we should assess the effect of consolidation and certify whether consolidation improve the capability of load-resistance, thus we can give suggestion for future constructions.In this paper, based on load test of bridge and strengthened bridge, we created resisting force model and load model, then formulated the limit state equation of RC bridge and analyzed the variation between un-strengthened bridge and strengthened bridge. Chief works and conclusions are summarized as follows:1. Single factor (concrete carbonation steel bar corrosion materials strength) related the resisting forces of RC bridges is considered and a resisting force model for multiple factor is created.2. Taking overlay into consideration, dead-load model of strengthened bridge is created based on dead load model of un-strengthened bridge. Dead load model is Gaussian distribution.3. Vehicle load is extreme value I distribution, which operates general traffic and rush hour states. Compared with actual circumstance, we adopted rush hour states to calculate and analyze the model.4. Adopting Fiber Bragg Grating, based on load test of un-strengthened bridge and strengthened bridge and the analysis of experimental dates, we assess the effect ofconsolidation and reliability of the bridge. After consolidation, the bridge is safer.5. Based on the resisting force model and load model of strengthened bridge, a bridge strengthened by gluing steel plate is analyzed. The influence of some parameters, such as common quantity of bonding plate function coefficient of steel plate variation coefficient of dead load and live load are analyzed.6. For the consolidation of bridge, firstly we should guarantee safety, secondly we should pursue the economy. Based on optimization theory, we created optimummodel of consolidation of bridge. On account of reliability index, we can conduct optimum calculation.