| The bridge of linking road has taken an extremely effect, along with the highway traffic undertaking of development at top speed. Most bridges have overstepped time limit and carried for thirty to forty, which built in the fifties, sixties and seventies of the twentieth century, and appeared many disfigurements, so they did not adapt to the rapid growing economic. Therefore, the old bridge to maintain and reinforcing have become a problem for awaiting to study solution.The expenses on the bridge maintain and reinforcing had accounted for 90 percent of total investment, only 10 percent of them had spent on the bridge of rebuilt in the United States annually. It is not enough to improve in the further in our country. Now the examination to the bridge health condition is being studied and experiment in many countries of the world. The system of the perfect bridge health monitors can verify the theories on bridge design and construction quantity, which monitor the state moved on structure in part and the whole, monitors with construction damage, attenuation resistance and its evolve the regulation, identify construction damage and its positions, proceed assess with predict to the bridge safety, enduring and early warning to the bridge safety misadventure etc. These works will rise the bridge safety that insure the function running, extending service life, it can also economize the expenses of the bridge maintain, increasing the performance of the bridge synthesize to use. Bridge examination and the meaning of the evaluation is:(1) Assessing the actual loading ability of the current bridge, for the usage of the bridge and maintain to reinforce the necessary basis in offering;(2) Establishing with accumulate the necessary technique in backlog data, establishing the bridge data bank;(3) The quantity of the examination bridge construction, making sure the dependable degree of the engineering, pushing with developing the old bridge assessment and new structural design calculation theories.Reinforce, reforms to the old bridge with make use of, which is effective measures to maintain the normal transportation in highway, its meaning and influence is profound to positive import with develop the old bridge reinforce, reforms with equipments, the reasonable makes sure to reinforce, reforms the project, it can let old bridge extend service life and economy funds.Assessing the bridge quantity good and bad should be main from its usage function, construction loading and use value to consider synthetically. Adopting the ability of loading adaptation rate and traffic capacity adaptation rate, the ability of drain off flood water adaptation rate and the ability of loading coincidence rate engage in calculation to synthesize to assess.The current in common using method in examination on bridge have:(1) Nondestructive test method;(2) Semi-destructive test method;(3) Synthetically technique;(4) Load test. Among them ex-three examination is to concrete strength, internal defect etc. But the load test is preceding an examination that synthesizes the evaluation to bridge whole construction characteristic and loading abilities.Making use of nondestructive test method and the load test had examined a double-curvature arch bridge for 17 bores completely. The examination work was divided into" bridge current conditions normal regulations examination" and" bridge current loading ability examination" two part.The bridge current conditions normal regulations examination contents includes:(1) The main structural concrete in bridge strength;(2) The carbonization depth of the main construction in bridge concrete;(3) The main construction in bridge concrete crack developed the circumstances;(4) The main construction in bridge concrete reinforcing bar rust-eaten of the circumstances;(5) The main construction in bridge reinforcing bar protector of thickness.Bridge current loading ability examination primarily is to pass the static load experiment complete of. Measurement item includes:(1) Vault deflection;(2) Vault, qu... |
