The Study Based On The Load Spectrum Of The Bridge For Simply-supported Beam Bridge With Continuous Decks End Of The Fatigue Life

This article as the National Natural Science Foundation funded project (51068005): Thepart of “the research in Road multi-span simply-supported beam bridge with continuous decksfailure mechanism”, To carry out a researching on the study based on the load spectrum of thebridge for simply-supported beam bridge with continuous decks end of the fatigue life.Focused on the simply-supported beam bridge with continuous decks bridge of deformationand stress under the load spectrum and temperature changes for the linear and nonlinearsimulation analysis and then carry out the fatigue test. The analysis shows that: Because ofthe simply-supported beam bridge with continuous decks structure is located in the largestparts of the main beam distortion, and the rubber bearing elastic compression not synchronousand cause adjacent span of movement deformation influence, resulting in the bridge deckcontinuous structure tectonic forces is very complex, and bridge deck continuous structurewith analytical calculation of the maximum tensile stress are beyond the concrete tensileultimate strength. Therefore, the simply-supported beam bridge with continuous decks bridgeput into use, the bridge deck continuous joint of concrete will be irregular subtle fracture andwith time gradually formed a cracked, potholes and other diseases, it seriously affects theservice life of the bridge structure itself and its driving safety.In this paper the first part is the theory analysis, mainly by means of the finite elementsoftware to simulate continuous structure bridge in various conditions (temperature±20°Cthe load spectrum, temperature±20°C+the load spectrum) role, under the action of stressanalysis, determine the cause fatigue failure of the main reasons is subject to the live loadeffect. And through parameter analysis method to study the influence of bridge continuousend force factors, by changing the modulus of elasticity of the bridge deck pavement,changing the thickness of the bridge deck pavement under various conditionsthe force ofcircumstances. The analysis found that: with the increase of modulus of elasticity of deckpavement, bridge deck continuous side suffered the largest tensile stress increased also; withthe increase of the thickness of deck pavement, bridge deck continuous side sufferedmaximum tensile stress is in smaller.In the second part is test research, According to the most unfavorable conditions of stressamplitude on fatigue life influence, carry out model fatigue test, made six root monolithic Tbeam model, two combination, the establishment of three groups of bridge deck pavementthickness different two span bridge continuous simply supported T beam test model. Through the fatigue test found that: Pavement layer thickness and bridge deck continuous seamstructure fatigue performance of proportional relationship; Fatigue test is influenced by manyfactors (stress amplitude, load limit, loading frequency). This paper studies have a wide rangeof theory and application value, and there is some certain reference value to the bridgeworkers.