Evaluation Method For Prestressed Concrete Bridge Based On Detected Effective Prestressed

Because concrete of prestressing force has a lot of advantages such as good behaviors, it has already become the most frequently structural pattern of highway bridge of our country.Under the function of condition of construction,matieral envirtion,precess of using and matieral,Steel bunch of prestressing force will appear various damage,and then cause the reducing of effective prestessed. So the research of appraising the concrete bridge of prestressing force based on the real value of effective prestessed, have important project meanings.As an important part of the Western Project about Communication Science and Technology entitled《research on the prestressing force detection technology about large and medium prestressed concrete bridges》,This paper has bringed forward the method of appraising of prestressing concrete bridge based on the real value of effective prestessed for the first time.First of all, this paper has carried on systematic research to the calcaulating method of prestressing force,and has bringed forward two basic parameters for appraising prestressing concrete bridge which based on theory value of effective prestressing force, i.e. stress and degree of prestessing.Secondly, this paper has bringed forward method of equivalent parameter of appraising the concrete bridge based on the real value of effective prestessed. Basing on the current criterion, this paper has improved the calculating formula of lossσl1 and lossσl2,consulting "the concrete design specification"(GB 50010-2002) and combining the calculating technology of the special-purpose software of the bridge,and has provided the method of imitating variation tendency along the longitudinal of a bunch of real effective prestressing force by changingμ,k andΔl, and has appraised to the structure of the bridge utilizing special-purpose software of the bridge.Moreover, this paper has introducd the method of degree of prestressing appraising of prestressing concrete bridge which getting sectional reality effect of joining forces, based on testing the initial stress of the ordinary reinforcing bar of section. It has made sure of the appraising the criterion through comparing with the real degree of prestressing and designing degree of prestressing, so as to determine the nature on appraisal to the structure of the bridge. Finally, this paper has compiled the procedure of calculating equivalent parameter and the procedure of section balance utilizing Visal basic, and has introduced its principle of establishment and procedure function, and has offered technical support for appraisal method described above.The comprehensive method of appraisal for prestressing concrete bridge has been offered by research of this paper, and the basic thereunder has been offered for the maintainrance of the concrete bridge,which will avoid judging blindly, save time and human resources, increase its service life,avoid unnecessary destruction, and fill in the blank of the appraising concrete bridge of prestressing force on the basis of the surveying value of prestressing force both at home and abroad.