Study Of Distress Treatment And Reinforcement Method Of PC Continuous Rigid Frame During The Process Of Construction

With the increasing maturation of bridge construction technology，such as the highstrength concrete, the high strength reinforced steel bar, the prestressed force and so on, thelong-span prestressed concrete continuous rigid frame bridge has developed rapidly day afterday in the recently short several dozens. Along with the development of transportationenterprise, the prestressed concrete continuous rigid frame bridge has obtained widespreadapplication in modern bridges since the60’s in our country, and a large number ofworld-class long-span bridges have been completed successively. But, distresses commonlyoccured during the process of the construction of prestressed concrete continuous rigid framebridge. So, to analyze and study the reasons of these distresses and propose effectivemeasures to prevent, control, reinforce and maintain have the significant practical meaning.In this paper, the distresses occured during the process of the construction of prestressedconcrete continuous rigid frame bridge and the meathods to reinforce the bridges aresurveyed and concluded, on this basis, combined with the inspection and analysis of thecauses of the distresses occured during the process of the construction of a bridge in foshan,the methods of making use of external prestressing and cross-partition, the combination ofstiffening rib and reinforcement are proposed, and the feasibility of these methods is alsostudied systematically.The main tasks and achievements in the paper are as follows:(1) Themain distresses and causes are briefly stated based on the inspection report of the distressesoccurred during the process of the construction of a bridge in foshan.(2)Though the analysisof the main distresses and causes, which include the crack of the bottom box caused by theradical force of the prestressed beam, pre-stressed pipelines generally are not allowed toposition, larger vertical deviation, severe local bending and so on, some suggestions to dealwith the distresses and four kinds of reinforcement are proposed.(3)Using the road andbridge professional software GQJS9.2, the mechanical properties of a bridge in foshan areanalyzed before its reinforcements, from which we can see that the stress state of the mainbridge section can basically meet the full requirements of prestressed concrete; in the mostdisadvantaged, the most the nagetive load, its intensity of the box-section floor can also meetthe regulatory requirements, the minimum thickness of concrete protective layer is smallerthan the smallest linear pipeline concrete cover, and the steel beam under the partial radicalshear force can also meet the requirements of norms.(4) Using the finite element analysissoftware ANSYS, the mechanical properties of a bridge in foshan are analyzed after itsreinforcements, from which we can see that the use of additional esternal prestressing cable and cross-partiton, stiffening rib combination of a bridge in foshan reinforcement method isfeasible.