The Study Of Stability For The Super Wide Round Ended Thin-walled Hollow Pier

The super wide round ended thin-walled hollow pier is a spatial plate and shell structure,its mechanical characteristics is very complex, the stability problem of the structure of the bridge has a close relationship with security and economic issues. The local stability of the pier,the standard does not clearly defined,and is still used the experience to be resolved. It ismainly used to control the thickness of the pier wall and set the diaphragm to enhance thelocal stability of the bridge pie. The paper made a research about the local stability ofthis kind of bridge pier, based on the4line railway stations in rounded shape super widethin-wall hollow pier in DaShaPing for practical engineering.Research on the stability of bridge structure has the very high scientific value andpractical engineering significance. The paper summarizes the stability problem of bridgestructures about research history, current situation and insufficient existing in currentresearch at home and abroad. With the Pier No.12for research object, introduces the ultrawidth rounded shape thin-wall hollow pier structure and design characteristics, carries on apreliminary discussion about the local stability of hollow pier.Based on the engineering example as the background, the paper uses the finite elementsoftware ANSYS to establish the solid model of the bridge. First of all, make a study to thetwo model of a vertical baffle plate and the vertical partition about the local stability of thepier wall, concluded that the vertical clapboard can obviously increase the pier local stabilityand has a high degree of stability of the wall safe reserve, without a vertical baffle pier modelalso has a certain stability security reserve and strength to meet the requirements. so the onlyconsider its impact on the local stability of sense, the vertical partition can cancel completely.In addition, by changing the wall thickness of the bridge pier and the concrete strength grade,concluded the rule of their impact on the local stability, also found that when the pier wallthickness to a certain value, the pier cross-section produced large tensile stress, and shafts ofintensity reached a limit state, however, the local stability of the pier walls and higherreserves. As a result, the wall thickness of hollow pier shoulds not be too thin, can control thewall thickness by strength, the stability of meet the requirements.For an actual bridge engineering, bridge pier there may be a certain construction error,the geometric nonlinear and the elastoplastic of concrete materials may have a certaininfluence to the local stability of hollow pier. In the paper, through the consideration of theabove three aspects respectively, the local stability of hollow pier wall is analyzed, found thatconcrete material of elastic-plastic have a large effection on the local stability of the bridgepier. Therefor, for this kind of bridge pier local stability, it should be included theelastic-plastic of the concrete material, we should make a elastoplastic stability analysis. Although the geometric nonlinearity and initial geometrical imperfection of the pier wall havelittle impact on local stability of the pier wall, but in order to make the bridge pier can bemore safe and reliable use after the normal operation of railway, we should also be strictly todo according to the requirements of relevant standards and technical regulation in the processof construction.