He Prestress Loss’s Finite Element Analysis And Experimental Study

With the development of the bridge, our country bridge has grown from asimple, small span, single bridge to the complex structure, span, the bridge diversepatterns rapidly in new era. With the development of the bridge, its materials and themethods of construction of the structure also needs to be more modern technology,which includes prestressed concrete, It makes the bridge,s span, structure weight,stability and durability for using and the cost of the project to increase the next level,all of this makes use of various prestressed bridge widely. For the prestressedconcrete structures, The size of the loss of prestress effect the size of the effectiveprestress, thereby affecting the whole structure and even its performance. So it begsthe crucial question is that the size of tensioned prestressed tensile force and the sizeof the actual pulling tension. How to ensure these problems, in short, is how to getthe impact of the losses caused by prestressing. Therefore, to determine the size ofprestressed related to the stable and durable of the bridge structure. If the estimate istoo high, which too large tensile force will to lead strand pulled off or member isfracturing. So how to determine the value of the prestressing loss of values is animportant part of prestressed concrete structural design.In order to determine some rules of the prestressing loss in this paper, Startwith the reality, we will though the field measurement values to come to the valuesof the prestressing losses. In detail, it is that though producing the scene three testbeams (for observing the different conditions of the prestressing losses, we adopt abending design for prestressed steel for the one of two beam, which grouts after thetension completion, and the angle between them is different. the third piece is the useof straight design for prestressed steel, which is designed to not filling), and doingprestressed loss test for them and the Shiyan ShenDingHe bridge. The method is: inthe test beam and the tensioning end of the test section to install cable dynamometer;In three experimental beams4equinoctial embedded steel type sensor, through themto get the actual effective prestress value, and to compare whit the loss of prestressstate under different conditions. Then referring to "Reinforced Concrete and Prestressed Concrete Bridge Design Specifications" and other various specification,using Midas/Civil for modeling analysis on the project on the3test beams and thebridge to get the theoretical data. Finally, though analyzing the actual and theoreticalvalue of the loss of prestress, and coming to some conclusion.In this paper, we will not only identify some laws of the prestressing loss, butalso find that the main factors of the prestressing loss. Thus, in base of theconclusion and laws of th the prestressing loss, we use the sensitivity analysismethod to simulate the effects of the selected factors, which adopts Midas/Civil, andthen analysis them, in order to get the effect of the main sensitivity parameters of theprestress loss.