Time-Vary Law Of Bridge Bearing Capacity

In china's economic construction and infrastructure construction of rapid development constantly, the road traffic flow is increasing, the bridge engineering facilities in China play an increasingly important role. Existing bridges'bearing capacity begin reduce, some bridges appear low bearing capacity, structural damage and other issues. How to evaluation the performance of active bridge has more and more got the attention of scholars both at home and abroad. Based on computer software as research tools, through establishment of concrete structure bridge model, research the bridge bearing capacity in time-varying under the influence factors of change, finally get the time-vary law of bridge bearing capacity.This article selects three different bridges structure to analysis bearing capacity:rectangular concrete beams, T-beam concrete beams, and hollow slab beam. First, establish finite element model, make reasonable arrangements for model size, tensile region heighten, restricted location. Select reasonable constitutive relation to perform simulation model. This article takes beam in midspan position to load, and then get the load-deflection curved shape. Finally induce the influence factors of bridge bearing and to calculate.the factors are:concrete compressive strength, concrete crack, reinforcing steel bar corrosion, reinforcing steel bar yield strength, etc. Get the numerical value in different time and sort out to a table, then evaluate the existing models and load, draw the bridge bearing change curve in different time scale.Through the above analysis results, and then through the observation and analysis of the bridge bearing can get the conclusion:the concrete have small influence on the bridge bearing. The bridge bearing vary is the influence on reinforcing steel bar corrosion. Until the carbonation depth reach the reinforcing steel bar position, the bridge bearing unchange in principle. With the reinforcing steel bar corrosion ratio step up, the bearing capacity is reduce gradually. In the end, this article obtain function of selected bridge.