| The thesis puts forward the idea of the strengthening prestressed plate beam with HTRCS(High Toughness Resin Concrete with Steel Wire Mesh)for the first time,based on improving the rigidity,ductility,bearing capacity and integrity of concrete plate beam,adopting material test,theoretical analysis,indoor full-scale static test and fatigue test as vertification.It analyzes stress mechanism and failure process of the reinforced prestressed plate beam systematically,and proposes the computational analysis method of reinforcement pattern of prestressed plate beam.The research can provide scientific basis and theoretical support for reinforcement and theory design,construction control decision,and maintenance and management of operation of the prestressed plate beam,which has sparkling significance,provides practical values on engineering and carries great prospectiveness and advancement.The main research contents are as follows:1、The thesis intends to introduce the general development and the trend of prestressed concrete plate beam bridge and analyze systematically and comprehensively the cracking and disease of hinge joints relying on a highway that was detected every three years,which reveals the formation and failure mechanism of the crack.The system is based on B/S mode,adopting J2EE architecture,choosing Microsoft SQL server 2008 database,and establishing the system of technical conditions evaluation of bridges,and it will form the intermediate and results of technical condition evaluation automatically,supporting data export in Excel,Word and PDF format.It functions to compare and analyze every detection results,find the development trend of diseases,send warning signals,and provide basis for avoiding or reducing diseases of this kind and explore the rational and effective reinforcement method.2、Starting from the angle of reinforcing the hollow slab,the thesis examines the best mix proportion of resin concrete substrate,conducts detailed experimental research for reinforced substrate and determines the basic parameters of the material.From microscopic view,it adopts polypropylene fiber and special scrap to explore experiments.From macro perspective,the author makes toughening test with adding high-strength steel mesh.As the macro stress flow needs serial transmission after the reinforced substrate cracking,it is necessary to make detailed experimental research on concrete slab with high-strength steel mesh and analyze the process of force bearing.Meanwhile,according to elastic beam theory and composite section assumption,deriving calculation formula of bearing capacity for the composite material slab,obtaining the rational reinforcement ratio,and putting forward the transmission calculation formula of reinforcement ratio of reinforcement beam.Also,it comes up the rational reinforcement ratio of full sized beam.3、The author explores the static load test for 4 beams which are applied to full-size datum beam static load test,full-size beam without steel mesh static load test,full-size beam with a little steel mesh static load test,and full-size beam with proper steel mesh static load test.Compared the reinforced beam with datum beam,the functions of cracking load and failure load are significantly improved.As a result,the stiffness of the beam has been increased by 10%with this reinforcement method on normal load level.As the load increased,the deflection decreases greatly and reinforcing layer receives more capacity when bond with the original concrete when it comes to plastic stage.The final failure mode is that the cover of concrete of the original beam to reinforcement is completely drawn off.4、The thesis explores how to choose the proper concrete,regular reinforcement,prestressed steel strand in order to construct constitutive relationship with the reinforcement material and derives the calculation formula for the maximum reinforcement ratio of the reinforced beam.The paper illustrates how to choose two modes to calculate the bearing capacity at the same time:①yield of regular reinforcement and prestressed reinforcement subjected to tension.②yield of the high-strength steel mesh of reinforcing layer or abscission and fracture of the reinforcing layer;Calculating the bearing capacity by strip method and modified crack method of compensation referring to the standard,inthe first failure mode,the measured value of bearing capacity of the reinforced beam has improved 19.39%,and the theoretical value also has improved 15.67%.Under the circumstance failure mode 2,the measured value of bearing capacity of the reinforced beam improved33.82%,and the theoretical value improved28.38%;The analysis results are in accordance with the test value and the applicable calculation method was put forward.5、The 4 pieces of standard beams are adopted as the basis,and the author applies the common hinge-jointed plate method to verify the accuracy of beam-slab composite and solid element and analyze the cause of producing error from other methods at the beam position line when simulating the bridge by solid element.The paper also analyzes the lateral stress mechanism of reinforcing the hollow slab by this reinforcement method,simplifies the calculation model and proposes modified method of rigid-joint slab and modified G-M method to calculate the transverse distribution of the load.The influence line of transverse distribution of the reinforced beam is gentler than the original beam’s,which reveals that the reinforcement method has strengthened the capacity of cooperative bearing.The slab bearing are mainly cooperative bearing,the transverse distribution is more uniform,the lateral bearing has improved greatly,and the traditional hinged-jointed plate method can not satisfy the transverse distribution calculation of this reinforcement method.6、The thesis is divided into 5 sections to investigate the vehicle flow,axle-weight,and wheel base in detail,it also forecasts the traffic volume of 100 years by using the theory of grey system prediction.Statistically according to the frequently-used lto7 type vehicle division standard and the number of axles.Simplify all the vehicles into 10 types according to principle of fatigue damage accumulation equivalence,put forward the heavy traffic highway simple supported beam bridge equivalent standard and 3-axle and 4-axle fatigue vehicle model,compare and analyze the typical fatigue vehicle models in both domestic and abroad.Besides,we need to discuss the rationality of the fatigue vehicle,which can provide the reference for fatigue vehicle of our country.7、The author uses fatigue property test for reinforced hollow slab using the fatigue standard vehicle,and analyses the variation law of the stiffness,strength and residual deformation of the slab in the process of the test.There was no abnormal condition in the fatigue process and after four million times’ fatigue load,the residual deformation of the beam was small;In the heaviest static load condition,the maximum deflection was in accordance with the strain,which was accorded with the plane section assumption;There was no stiffness degradation phenomena of the beam;After four million times’ load,the reinforced beam didn’t fail,and the reinforced beam still had potential of fatigue.Then in the static load test,compared the mechanical behaviour of the reinforced beam without fatigue load,the mechanical behaviour,bearing capacity,and cracking property were almost invariant,and the residual deformation increased,The fatigue property of the reinforced beam meet demand.8、According to the research results,the author adopts C#language,chooses Microsoft SQL Server 2008 R2 database,achieves the system program of the reinforcement method to reduce the work force and improves the design efficiency.The system has a strong expansibility and availability and will form the result of reinforcement design and the whole intermediate process automatically.Moreover,it supports the data export in Word,PDF and CAD format. |
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