Research On Combined Support System Of Cast-in-place Box Girder Under Complex Terrain

From twentieth Century 70 years,cast-in-place box girder have developed rapidly and been used extensively in China.A large number of bridges are used of this construction technology.From the Tatara bridge to Sutong Bridge,from the Hangzhou bay bridge to Xihoumen Bridge,steel box girder is widely used,many bridges have been built in our country and in the construction of using this construction technology.The project lacated in the west outer ring of Nantong is a major transport hubs.The rich water system and complex landform make the construction of the project difficult.Considering the characteristics,the project is decided to use the construction of hanging basket combining with full scaffold construction.Based on the work progress,the paper focuses on the construction technology of full framing support template using in cast-in-place box girder,containing the research of the design,manufacture and checking technology in scaffold and template;the construction method and technology of cast in place box beam and bailey frame and the use of computing technology.This paper provides a set of successful construction technical data for the construction of cast-in-place box beam under complex landform.The main work includes the following aspects:(1)The key technologies of support foundation treatment,support system design and construction are studied,according to the Yangtze River Road(West Road along the road to North)the actual situation of cast-in-place box girder construction project ?.The hanging basket,full support and frame theory combined the feasibility of combination body support design system,Through calculation comparison.(2)The construction technology,support erection and support preloading technology are studied,combined with cast-in-place box girder construction situation.The feasibility of erection scheme of cast in place box girder composite bracket is determined,through the observation of scaffolding erection,template installation,box girder pouring process.(3)Analysis of cast in place box girder erection construction key factors and control points,in the Yangtze River Road(West Road along the road to North)cast-in-place box beam as a model of II project,combined with cast-in-place box girder bracket erection process and box girder pouring construction project.The key factors to control the bearing capacity of the support are determined,such as foundation treatment,scheme selection of composite support erection,preloading of support,by analysis.The support of the support should be combined with economic factors while ensuring the bearing capacity.