The Carrying Capacity Of RC Beam Bridge Based On Calculating Coefficient And Crack Characteristics

With the road transport has developed rapidly domestie,more and more bridges are subjected toheavy load.Some bridges show different degree of disease.For example, insuffieient eapacity of existing bridges,aging and other damage has been a global problem. So it is critical to ensure safety and reliability on the scientific assessment of the reliability of existing bridge.This thesis aiming at Reinforced Concrete Beam Bridge based on the achievement of bearing capacity evaluation. And the briefly content of this thesis as follows:(1) Summarized the general disease of the old reinforced concrete bridge were, and the mechanism of disease.The crack control standards in different country are studied. Although countries regulate different demands of crack, but will crack width, height, the distance as a measure of the important index of component performance can be crack statistical parameter for evaluating the important basis of structure bearing capacity.(2) The thesis based on the existing bridge evaluation by calculating methods, considering bearing capacity of bridge deck of irregularities injuries and the influence of impact coefficient caused by vehicle.Recised the live load effect of correction coefficient and reaction in structure resistance expression..Through comparison the load effect and resistance effect of the structure by calculating, eventually makes assessment of bridge bearing capacity.(3) Based on the summarization of crack development of the reinforced concrete beam under stress stages,put forward three statistical parameter cracks. Application of this three crack statistical parameter and their respective weights defines the concept of fracture statistics, and used HAP to identify different weights and get crack index expression.(4) Using crack index put forward a kind of new method by calculating bridge bearing capacity. Will this capacity evaluation method for a simply-supported T girder bridge and a simply-supported I girder bridge. The evaluation results obtained with the original bridge load test results were compared. Research results show that the bearing capacity based on crack index of the evaluation method is close with load test evaluation method. And avoid load test the disadvantages of not economic time-consuming. In this paper, by calculating coefficient and based on the bearing capacity of the crack index evaluation methods can be used for RC beam bridge rapid assessment of carrying capacity.