Jiashao Bridge Project
Zhejiang Jiashao Bridge Investment & Development Co., Ltd.
Located in Zhejiang Province of China, Jiashao Bridge overpasses the channel segment of Qiantang River and connects the cities of Jiaxing and Shaoxing. The total length of the bridge project is 10.137km and it is eight-lane expressway.
The hydrologic condition of the Qiantang River is very serious with design flow speed at riverbed cross section of 7.5m/s. Due to the influence of raging bore and swift current, the main channel for navigation is movable, the possible range is about 2 kilometers. As the tide range is about 7.0~9.0m, the water depth is less than 2m in time of low level tide, thus transporting ships is only possible during the limited high level tide time and large scale ship-lifting equipment cannot be used downstream of Jiashao Bridge.
To protect the famous scene of the Qiantang tidal bore and to reduce the construction risks under bad hydrologic conditions, an innovative structure design was adopted for this Bridge Project. For the main bridge design, a six-pylon cable-stayed bridge with five 428m-long main spans is adopted. Single-pylon structure, with the top of pile caps located under the riverbed surface is used to control the water blocking rate of the bridge structure. The superstructure of the main bridge is separated by four-plane stud welding streamlined flat steel box girders. The total steel girder width reaches 55.6m.
To increase the vertical stiffness of the main girder effectively and control the temperature deformation of the whole 2680m long main girder, an innovative Double-Support & Hinge (DSH) system was adopted. In the DSH system, these are two vertical supports set at both sides of the pylon for steel box girder at the pylon bracket area, and four two-way sliding bearings for one pylon. Using the DSH system, the scale of pylons and foundations were reduced, and $139.8 million was saved compared to traditional designs without hinges.
Regarding the approach to bridge design: in order to enhance the integral stability of the structure with tall and flexible single-pile-column foundations, I-shape transversal beams were set between the separated decks. The single-pile-column substructure had a small water-blocking area, which had a small influence on hydrology. And with no pile cap, it avoided the risk of cofferdam construction from the tidal bore.
The completed Jiashao Bridge has an elegant and integral structural shape. It is harmonious with the surrounding environment and local culture. The application of the DSH system and hinge-related technologies, including design, manufacturing, erection, monitoring, and maintenance promotes the theoretical and technical development of multi-pylon cable-stayed bridges and contributes to the promotion of multi-pylon cable-stayed bridges worldwide.
“On behalf of Zhejiang Jiashao Bridge Investment & Development Co., Ltd of China, I am very grateful that the IRF has awarded the 2016 Design GRAA to the Jiashao Bridge project. It was a great challenge for the designers, CCCC Highway Consultants Co., Ltd., to account for the natural landscape of the Qiantang River tide and incorporate appropriate technical and material innovations for design and construction. I warmly welcome bridge specialists from around the world to come to China and visit the project; we are happy to exchange and share experiences and concepts with each other. Thank you again.”
Vice General Manager of Jiashao Bridge Investment & Development Co.,Ltd.