Research On The Detection Method Of Effective Prestress For Prestressed Concrete T Beam

At present, prestressed concrete technology has been to be a mature and excellent engineering technology, but it is not perfect, because the loss of prestress has not been solved well.People design prestressed structures,andcalculate the width of crack,cracking strength, bearing capacity of thesection, and evaluatethe bearing capacity in actual engineering application, which are all related to the detection and identification of effective prestress.If the effective prestress is overestimated, it will affect the safety of the structures, even cause the engineering accident. If the effective prestress is underestimate, it will not give full play to the performance ofthe structures,which is equivalent to a waste of material.Therefore, how to get the effective prestress accurately, which has become a major issues.In this article, the authorselects a prestressed concrete T beamwith calculated span length 28.8 m fromYe River Bridge as the research object.At Pingshan,we didstatic load testand decompression loadtest, and test the effective prestress in the beam. The main content is as follows:Firstly,on the basis of reading and analyzing relevant literature at home and abroad,the author summarizes the existing bridge prestress testing method and related theory, and introduces the basic theory of decompression moment testing method;Secondly,use the software ANSYS to establish a FEM model for the testing beam,and simulateall the test process, calculated the decompression load, cracking load and yield load by theory, and provide a reliable basis for the test.Thirdly, choosing a prestressed concrete T beamwith calculated span length 28.8 m. According to the current specification the prestress loss in the beam is 18.47%, whilethe prestress loss is 15.88% determined by the decompression load test results. In this paper, the reliability of the test method of the decompression moment is proved.