First Assembled Bent Cap Successfully Completed on Nanjing-Jurong Intercity Rail Transit Line

On May 5, 2020, the first prefabricated bent cap for Nanjing-Jurong intercity rail transit project was successfully completed. It took 2 hours and 21 minutes before and after the construction to realize the "building block" construction of the bridge substructure.

A total of 27 prefabricated bent caps were designed for a length of about one kilometer along the intercity rail transit line. The prefabricated assembly technology was used for the first time in China for the substructure of the rail transit project, having filled the gap in this field.

In the past, it took 14 to 20 days to use the cast-in-situ technology for the erection of bent cap brackets, while the installation of precast bent cap takes only 2 to 3 hours to complete. Even in consideration of the precast time of the bent cap in the prefab, the construction time can be reduced by about 7 days, thus substantially shortening the construction period of the project and reducing the road occupation time. At the same time, because the prefabrication of the bent cap is not affected by the weather and the surrounding environment, the construction convenience is improved, the quality of the bent cap is guaranteed, the danger of working at height is avoided, the hidden safety risks are reduced, thereby being worthy of promotion.

In order to ensure the successful application of the prefabricated bent cap technology, the bridge institute organized technical forces to carry out scientific researches, and proposed a connection scheme for the combination of ordinary steel bars and prestressed steel bars and grouting bellows, which effectively dwindled the connection difficulty and launched the full-scale destruction test for the first time in China, providing sufficient test and data support for the promotion of precast bent cap technology.

The successful application of the prefabricated bent cap on the Nanjing-Jurong Intercity rail transit line marks the domestic advanced level achieved by UCD in terms of the prefabricated assembly technology of rail transit bridges, which has promoted the development of the prefabricated assembly technology in the industry. This technology sees broad prospects for its application in the field of rail transit bridges.