Discussion And Research Of Stress Measurement Methods Of Reinforced Concrete Bridge Structure

Since reform and opening, China's economic construction was development rapidly, people's living standards was improving, transportation and other infrastructure carried out also in full swing. Bridge, as a transportation hub, is playing an increasingly important role, has become a regional economic development bonds. As the rapid development of China's economy and the transport, the development of highway bridges are very rapidly increasing , on the one hand ,the numbers of new bridge was more and more, on the other hand ,many of the existing bridge has gradually entered a phase of maintenance and repair.Highway bridge is the throat of the transportation , its carrying capacity and capacity is the key to the road. Therefore, how to test, assess the old bridge (and the new bridge) carrying capacity, maintenance, reinforcement, reinforcement to the bridge carrying the research,experiment and practice promotion of the effective methods to increase the level of issues , has attracted worldwide attention, So, how fast, accurate and scientific to evaluate the technology situation and carrying capacity of the old and new bridge has become an important area of research in bridge project, which reinforced concrete bridge structure is one of the main forms of bridge structure, and it is numerous.This article starts from the deficiencies of the existing method of bridge test , combined with the theory of ordinary reinforced concrete structure proposes a method of bridge reinforcement stress testing in case of damage not caused , Then gets the stress testing of the stress state of structures, and above all we analysis the relevant theoretical basis of its method, and then the feasibility of this method was compared and validated by the model tests and real bridge tests.The main research work included: Combined with the basic assumptions of the reinforced concrete structure, transformed section theory and stress and strain analysis theory, analysis the relationship of stress and strain of the cross section at different stages of the structure, clear the bridge structure load test phase, focused the structural analysis of phaseⅢa and phaseⅡ, and derived the calculation formula about rectangular case with double reinforcement , Thus derived the relationship between the concrete surface strain and steel stress (strain) in the bridge load tests phase;By the relationship between concrete surface strain and reinforced stress (strain) , proposes a method of bridge reinforcement stress testing in case of damage not caused , that directly test the concrete surface nominal strain to determine the steel stress; by statistical analysis the crack spacing data from the existing test beam, provide a reasonable test gauge for model tests and real bridge engineering examples, the proposed method in this paper is measured fit well with the strain energy of the plane section assumption through the model test ; Respectively, through the model test and real bridge engineering examples verify the accuracy and feasibility of the stress testing methods.