Study On Key Construction Techniques Of "900 T" Heavy Prefabricated Box Girder In WuGuang Railway Passenger-dedicated Line Project

WuGuang passenger-dedicated Line Project is an important component of China's high railway scheme. It will significantly release the transport pressure of the southern part of JingGuang railway and effectively improve the national transportation capacity. It will be beneficial to the development of our country's economics and modernization. Prefabricated Box Girder technique is a new type of prestressed concrete bridge construction approach which is well known for its strength, stability and convenience. However, its extremely heavy weight and bulk often lead to some difficulties to manufacture and move. Particularly, the key construction techniques can decide whether the whole project can go smoothly. This paper focuses on the key construction techniques of heavy prefabricated box girder based on the project" WuGuang Railway Passenger-dedicated Line Project" of China Railway 16 Bureau.The researches mainly lie in the key techniques of concrete works, construction technology, Prestressed Tension Technology and Grouting technology. What should be noted is that the experiment of high performance concrete provides some useful information. In conclusion, in context of the same mixing proportion of the original materials, the liquidity of new concrete sample tends to be descend when the modulus of fineness of the sand minishes. Then, the viscosity will increase and the strength of the concrete will reduce. In addition, the strength of the concrete tends to reduce while the mud content of the sand increases. With the increase of the mud content of the sand in the fine aggregate, the concrete's dielectric flux becomes larger. Meanwhile, the shrink of the concrete in the early age will be constrained when the mud content increases. Vibration experiment indicates that the optimum time of vibration is 12 s. Finally, the paper also points out some tips and quality controlling strategies in those key construction techniques. The results of this research can be references to the same engineering projects, it is beneficial to practical engineering projects.