Experimental Model About Distributed Rule Of Effective Prestress

At present, large number of pre-stressed concrete bridges has already constructed in main highway of our country. According to insufficiency of pre-stressed force, among of many pre-stressed concrete bridges which after putting into service, appeared all kinds of diseases like that main span deflections in the middle of span quantity oversized, the crack on the box girder and so on. Therefore, method studied of measuring pre-stressed force effective value has the important practical significance and the project practical value.West the Ministry of Communications the topic "Long, Middle Span Concrete Bridge Pre-stressed Examination Engineering research" the special five-pre-stressed muscles effective pre-stressed examination engineering research main content. This article using the basis of the Ministry of Communications test subjects come to the bridge on the effective detection method, the large proportion of the beam model of prestressed steel beam for tension testing. Methods:the power method and the static method. The results of the model data were analyzed in order to be measured and regulating the relationship between the value of code result and measured result.As the power method and the static method in operation on the error and environmental factors, so they have a certain difference exists between them. the power method about Tension force in cases of low-grade by environmental factors, measuring result is instability, so the model experiments in measuring result for access to the static method value. Code result is based on the "Code for design of Highway Reinforced Concrete and Prestressed Concrete Bridge and culverts ", that is, in control of tension known circumstances, the vertical steel beam along the measuring point of tension results.By the model test data analysis and found that, by regulating steel beam from the vertical tension along the side is conservative, and test result bigger than the code result, there is a certain distribution. According to model test result and code result in the value of comparative analysis to find the relations between the two, verified by the three assumptions.In real bridge design and construction, the anchor under control can be reduced based on the actual situation properly to prevent the tension on the bridge under the unfavorable factors.