The Construction Control And Dynamic Performance Study Of Extrados Cable-stayed Bridge

Low-pylon cable-stayed bridge is a new type of bridge which has got development in recent years. The force characteristics is between the girder bridges and cable-stayed bridges. And it has the advantages of both the the girder bridges and cable-stayed bridges. As a new type of bridge, the research of construction control and seismic design toward it is less. It refers to continuous girder bridges in linear control and to cable-stayed bridges in cable force control. There is not a unified design standard for the seismic design of this type of bridge.Under the background of the Jinhu interconnection partial cable-stayed bridge this paper has done a deep analysis of the linear control, cable force adjustment in the construction control and the seismic response of this bridge. The main contents are as follows:1. This paper mainly introduces the adaptive theory and the application of adaptive method in the Jinhu interconnection partial cable-stayed bridge. The main content is linear control, which has made a detailed comparison of the measured results with the calculated results. The effective level forecast was made and used to guide the construction.2. This bridge adopts two times cable stretching method, that is, making the first cable stretching when installation, and the second after the closure of bridge structure. With the typical case study of the Jinhu interconnection partial cable-stayed bridge, this paper introduces the application of the impact matrix method and trial method in the cable force adjustment calculation after construction. Meanwhile, it has done the model calculation with the finite element analysis software midas and Doctor Bridge.3. This paper introduces the relating theory of response spectrum analysis. With the background of the Jinhu interconnection partial cable-stayed bridge, it introduces the seismic response analysis method and finite element modeling process. According to the standard requirement, it has done the seismic response analysis to the structure under the condition of frequently occurred earthquake. And it makes the seismic checking under the frequently occurred earthquake. The results showed that the bridge can meet the security requirement of the "no damage in low-level earthquake."4. It introduces the earthquake response analysis theory under the high-level earthquake of the low-pylon cable-stayed bridge, the computing method of the section bending moment curvature and the construction principle of the dynamic finite element model. With the background of the Jinhu interconnection partial cable-stayed bridge, it has done the time-history response analysis under the seldomly occurred earthquake. The results shows that the piers’control section have been into the yield stage, but are not reaching the damage, having large safety reserves and satisfying the security requirement of the "no collapse under severe earthquake".