Mechanical Analysis Of Prestressed Concrete Composite Box-girdge Bridge With Corrugated Steel Webs For Multi-working Plane Cantilever Casting Construction

In Vietnam,the main structure of bridges is still pre-stressed concrete bridge.The application of steel-concrete composite bridge is just at the initial stage,though there are a few composite bridges,and concrete composite box-girder bridge with corrugated steel webs has not been applied in the practical engineering.However,similar to the development of bridges in other countries,it is an inevitable trend that steel-concrete composite bridges will finally replace the traditional pre-stressed concrete bridges.Therefore,in the near future,concrete composite box-girder bridges with corrugated steel webs will be applied widely in Vietnam.In the consideration of the structural characteristics and construction experience of concrete composite box-girder bridges with corrugated steel webs,the corrugated steel webs are installed before the propulsion of hanging baskets.At this time,by fixing frange plates above and below the webs,an I-beam is formed and it can bear the large temporary construction load,which could utilize the high shear buckling strength of corrugated steel webs.So,there comes Rapid Construction of Ripple Web,which uses the corrugated steel webs as a load-bearing structure to bear hanging equipment.This construction method has many advantages,such as short construction period,smooth and open work space,easy and safe propulsion of hanging baskets,convenient installation of templates,fewer workers,and so on.Based on these advantages,RW method becomes an advanced,efficient and practicable construction method for large-span bridges construction and will be applied widely.However,nowadays,this method has few applications in practical engineering,and there are few researches about it.Therefore,in order to further understand the characteristics of the RW method,it is necessary to carry out relevant research.It could provide some reference for the following application of this method,and promote the future development of Vietnam's bridge engineering.This paper relied a continuous rigid frame bridge with corrugated steel webs in China,which adopted RW construction method,as engineering background,and completed the following works:(1)A spatial finite element model of the engineering background bridge was built by the finite element software MIDAS.By defining the corresponding construction stages in the model,the construction process of the multi-face cantilever construction method-RW method was simulated.After considering the correctness of the model,this paper checked the safety of the bridge with the finite element model.(2)According to the construction process of traditional cantilever pouring,the corresponding finite element model was established and compared with the model which simulated the RW construction method.The two models were compared and analyzed from the force and deformation.And the similarities and differences between the RW method and the traditional cantilever casting method were obtained.(3)By finite element software,this paper established an accurate model of some structure of the PC composite box-girder bridge with corrugated steel webs at different construction stages of the RW method.The stress and deformation of the structure were calculated at different construction stages.With the calculation results,further verified the security of the bridge during and after the RW process.