The Prefacricated Techonology Of 900t Simply Supported Box Girder In High-Speed Railway

Prestressed RC box girder has many advantages, such as high integral stiffness, good anti-fatigue performance, low structural noise, simple and clear structural force, efficient, standard and quality reliable factory prefabrication, thus it is widely used in the new high-speed railway in China. So it it particularly important to satisfactorily complete the design intentions, establish reasonable construction schemes and construction technology and ensure the construction quality of such bridges.Firstly, this thesis describes the development situation of both domestic and international high-speed railway, compares and analyzes the structural characteristics of the high-speed railway bridge in different countries, and also compares differences of the different speeds’high-speed railway prestressed simple box girders in China. Combining with the engineering practice in the Beijing-Shanghai high-speed railway Danyang beam fabricating yard, the author describes the construction schemes of the 32m high-speed railway double-line, single-box and single-cell simple box girder (weighing up to 900t), including the beam yard’s design, the box girder’s fabricating equipment, the shifting beam equipment, the box girders’trial production and technical parameters test, etc.Secondly, combining with the engineering practice in beam fabricating yard, the author describes the construction technology of the 900t high-speed railway double-line simple box girder. A detailed description is given of the 900t double-line simple box girders’fabricating process, technical points and points for attention in the production link, which include selection of raw materials, reinforcement engineering, formwork engineering, workmanship of concrete placing, prestress construction, box girders’shifting and storage, etc.The thesis also expounds key technical difficulties to fabricate the 900t high-speed railway double-line simple box girders. Besides, the author introduces the key production technology to ensure box girders’production quality, safety and durability in the aspects of high performance concrete’s mix design and construction technology, prestress construction technology, control measures of box girders’subsequent creep camber and guarantee measures of concrete durability.Finally, in accordance with the relevant railway standard, we carried out a load test of the 900t high-speed railway double-line single-cell simple box girders made in this beam yard and performed a spatial nonlinear finite element analysis with general finite element software. A comparison was made between static load test results and theoretical analysis results, verifying the safety of prefabricated box girders.