Urban Elevated Rail Transit Segmental Bridge Construction And Control Technology

Elevated structure is an important form of rail transit (subway, light rail, etc). Its related technologies and crafts have been widely concerned. The application of precast segments assembly in the elevated rail traffic of foreign cities is more common and more mature. Because of its complexity and particularity, the start of the technologies is relatively late . Related technology research and summing-up is of very important value.In the paper, as the precast segmental assembly bridge on the fourth line of Guangzhou railway transport being engineering background and on the basis of a wide range of reading and reference existing domestic and international research literature information , the precast segments of short bed match mast and segment assembly craft is studied and expatiated . Especially, the precast segments and the method of assembly linear control is in-depth studied. The monitoring method of the grouting compactness is put forward. The main contents are detailed as following:(1)The construction techniques that segments are first precasted in plants(short bed match mast) and its key craft are introduced in detail. the controltheory and the method of the linear control with the short bed matchmast are detailed studied. The coordinate conversion formula based on thesix-point coordinates of short-term line of control is deducted.(2)Discourse the erection crafts of bridge girder erection machine in the process of the whole-span erection. Introduce bridge erection equipment-bridge girder erection machine and the working procedure of the process of the whole-span erection. Enumerate the parts of the bridge erection equipment and their functions to guide the process of construction(3)The crafts of segmental box girder in the process of the cantilever assembly are researched. Aim at the characteristic of the precast segments cantilever assembly, the key technology, the method of the linear control and the measures of correcting deviation are brought forward. Some useful conclusions and recommendations are drawed(4) Aim at the characteristic of the precast segments assembly bridge and by comparison, a non-destructive method is put forward. The method adopt the method of ground penetrating radar to detect the grouting compactness of prestressed ducts and the grouting compactness of joint mortar. This method can insure high quality of the segments assembly and promotes the value of use.