Application And Analysis On Cable-stayed System With Single-plane In Long-span Continuous Rigid Frame Bridge Reinforcement

With the development of the bridge technology, the long-span prestressed concrete continuous rigid frame bridge has been applied widely and rapidly because of its large capacity, scientific and reasonable stress situation, convenient construction, and other c haracteristics, but this kind of bridge also has prevalent disease, such as increasing def lections in the middle of span, easy cracking in the web of box girder, impacting the bridge’s bearing capacity and the stiffness.According to the mechanical characteristics of the combination system,on the bas is of its universal disease, the paper proposes consolidation ideas reffered to the longspan continuous rigid frame bridge with single-plane and fixed pier-tower-beam cable-s tayed bridge. This paper is based on the construction of a long span bridge in Forsh, using a software named midas civil to establish the whole bridge model to simulate the whole construction process, and make the following research works.Firstly, Basing on the bridge in Foshan, we build the bridge structual model with software of midas civil. And revise the model reffered to the actual test results, we name this situation as continuous rigid frame bridge before reinforcement. Lastly we c alculate its stress state,carrying capacity and deflection situation in all aspects;Secondly, We make a analysis of the design parameters for this kind of consolida tion system, Through the establishment of groups of different tower heights, different non-cable-stayed lengths and different arrangement modes of cable in high compliance with regulatory requirements, under the circumstance of same cable force, how the ef fects of main beam bending moment, girder stress and deflections change which result from these design parameters variation, and lastly determine the reasonable design pa rameters;Thirdly, Combining the rational state of cable-stayed bridge with the reasonable st ate of continuous rigid frame bridge, the paper proposes the reasonable bridge status t hat optimizates the state of girder stress and stops the deflection of girder by regulati ng the cable tension, and proposes the cable force calculation methods of combination system, using one module named unknown load factor method to determine a reason able cable force, and later using a uniqe difference program to calculate the initial co nstruction cable force;Fourthly, Basing on the bridge in Foshan, calculating its stress state,carrying cap acity and deflection situation before the reinforcement, and determine the design parameters of a single plane cable-stayed system. Lastly the paper analyses the effect of thi s system after reinforcement as a comparison.Lastly, The paper introduces the traditional method of prestressed external tensions method and its principles, making a contrast with the single plane cable-stayed bridg e system reinforcement, and analysing the respectively effect of its two methods.