The Economic Study Of Strengthening Scheme For Existing Bridge Within It's Lifetime

Bridge is not only one of the important integrates of the road, but also important part of the infrastructures for the country, so it plays a vital role in one economy. With the time pass and the rapid progress in economics, the problem of out-aged for bridge is becoming more and more serious, even becomes a problem merits international attention. Thereof, it is of great importance for the management department of bridge to measure, technically and economically analysize the old bridge, then to adopt economic and reasonable measure (scheme). But in home presently, when some measures are necessary to be taken against the degradation of resistance of the bridge, we often are localized on the ideas that the cost of (?)force is less than the reconstruct, and omit frequently the other costs and expenditures during the whole working life, unfortunately, these costs and expenditures occasionally are very large. Even considering the other costs during the whole working life, the measurement of reconstruction is often omitted in economic analysis. Other things constant, if the cost of reinforce is less than that of the reconstruct, while pay no attention to the reconstruct measurement, then it is no use for comparing.This study attempts to investigate the problem of economic analysis in comparative measurement for improving the present bridge resistance. On the theory of engineering economics, accompanied with laws of engineering techniques and computer science, at the same time, retrospect the related literatures, we attempt to go further the study on the above question. The main contents go as follow:Firstly, summarize the present reinforce techniques and its confine for employment.Secondly, analysize the mechanism of degradation of the structural resistance and the theory for the reinforce techniques, built up some models related with reinforce techniques, such as resistance degradation model, reinforce cost model and etc.Thirdly, according to the theory of structural resistance degradation and engineering economics, we consider the possible costs during the bridge working life, and build up the cost model of the whole working life. Thereon, separately set up the cost model of the whole working life and the year-cost models for the corresponding reinforce measure and reconstruct measure.Finally, build on the above theory, we analysize the structural status with a detailed bridge, and set up economic model, while authorize corresponding programme in MATLAB, and deduced economic results.The different cost models of the whole working life built up in this paper have wide applied value. It is important to point out that the year-cost models of the reinforce and reconstruct measure are suitably economic analysis model that could be applied in the conditions of different working life. Especially, by economic analysis with three measures for a certain bridge, this paper points out some general principles about how to choose the reasonable measure to improve structural resistance for references.