Research On The Arrangement Of Sea-crossing Bridge Large Box Girder Precast Field

Prefabrication technique of large span box girders has been used and developedwidely, and the development tendency is to apply the technology of onshore factoryproduction of entirely prefabricated large prestressed concrete box girder. Theconstruction technology can ensure the overall quality of bridge members, thereduction of difficulty of offshore construction work and cost, increase of theconstruction speed. The arrangement of sea-crossing bridge large box girder precastfield is one important process of prefabrication of large box girder, but the techniqueneeds to be further researched. The paper demonstrates and studies the arrangement,technique and structure design of sea-crossing bridge large box girder precast field byanalyzing service condition of each functional area of precast field, efficiency ofprefabricated construction and technology of transportation, loading and unloadingprecast members.Firstly, the paper compares the efficiency and economy of different loadingprocess of box girder, and determines to use the loading process of2400t transversecar to remove,1200t gantry crane to lift. Based on the loading and unloadingtechnology, the paper designs the layout of each functional area (box girders ofprecast, storage and shipment).Secondly, the paper designs and calculates the field the relevant structures,combining the layout and technology of precast field, to ensure that box girder willnot have cracks, resulting from high tensile stress of uneven settlement of foundationduring pouring, maintenance and storage period.Last, the paper introduces the construction technique of box girder precast fieldaccording to the designed layout.Practice shows that the layout and design of the precast is reasonable, which canmeet the construction requirements of precast of large box girders in the Jiaozhou baysea-crossing bridge. The layout, technique and structure design can be popularizedand applied in other similar projects.