On December 30, 2021, the Kaizhou Lake Super Bridge—the section of the Guizhou Province Jiangkou to Duge Expressway between Weng'an and Kaiyang—designed and developed independently by our company was officially completed and opened to traffic. It will begin operations at 24:00 on December 31, 2021.
Led by Yang Jian, Chief Engineer of the joint-stock company, Zhang Guofa and Liu Weiwei from the Third Survey and Design Institute of the Transportation Division, as well as Li Yinbin, Yang Hongbo, and Chen Yinggao from the Bridge Design Institute, all participated in the opening ceremony. The completion and opening to traffic of the Kaizhou Lake Supermajor Bridge marks our company’s entry into the “kilometer-scale bridge design club.”
The Kaizhou Lake Supermajor Bridge is a key control project on the Weng'an–Kaiyang section of the Jiangkou-Duge Expressway in Guizhou Province. It spans the Luowang River Canyon, and its main bridge is a 1,100-meter single-span steel truss suspension bridge. The side spans of the main cables are 302 meters and 143 meters respectively; the central span of the main cables measures 1,100 meters, with a sag-to-span ratio of 1/10. The heights of the main towers on the two banks are 139.0 meters and 141.0 meters, respectively. The main girder adopts a steel truss stiffened girder (a combined plate-truss structure). On the Weng'an side, a gravity-type anchor is used, while on the Kaiyang side, a tunnel-type anchor is employed. The approach bridges on the Weng'an side are constructed using pre-stressed concrete cast-in-place box girders; those on the Kaiyang side consist of pre-stressed concrete T-beams that are initially simply supported and then transitioned into a continuous structural system. The total length of the bridge is 1,257 meters.
The unique features of the Kaizhou Lake Super Bridge:
(1) The Kaiyang bank deposit area has a relatively extensive coverage, making it difficult for the main tower to completely avoid it. During the design phase, the main tower on the Kaiyang bank was positioned at the rear edge of the deposit area, and comprehensive protective measures were adopted specifically for the slope. This ensured the structural safety of the bridge and provided technical support for the construction of long-span bridges under complex geological conditions in mountainous regions in the future.
(2) For the first time, a split-type cable saddle was adopted. The mountainous roads on both banks of the Kaizhou Lake Bridge are steep and rugged, with narrow construction access roads that feature steep slopes and small turning radii, making it extremely challenging to transport large-tonnage cable saddles. The Kaizhou Lake Bridge employs a split-type cable saddle design, which significantly reduces the weight of the cable saddles during transportation and enhances the safety of cable-saddle transport along mountainous routes. This design holds great potential for wider application in future construction of suspension bridges in mountainous areas.
(3) The collaborative construction of the tunnel anchor for the Kaizhou Lake Supermajor Bridge and the twin-arch section of the Siping Tunnel represents a typical case of closely spaced tunnel excavation. The surrounding rock in such closely spaced tunnels experiences complex stress conditions, making construction particularly challenging. Based on the collaborative construction of the tunnel anchor for the Kaizhou Lake Supermajor Bridge and the Siping Tunnel, a special research study titled “Impact of Close-Proximity Construction Between Tunnel Anchors and Twin-Arch Tunnels” was conducted. This study delved deeply into the mechanisms underlying close-proximity construction and the associated mechanical behavior during construction. On this basis, the construction techniques for tunnel anchors and twin-arch tunnels in close proximity were optimized, ensuring both project safety and quality. The findings from this study provide valuable experience for the construction of similar projects in mountainous regions.
With the successful completion of the Kaizhou Lake Supermajor Bridge, the Weng'an to Kaiyang section of the Jiangkou-Duge Expressway in Guizhou Province has now been fully connected. As a result, the driving distance between Kaiyang and Weng'an has been shortened from 110.8 kilometers to 48.5 kilometers. This development is of great significance for building a highway ring road around the central Guizhou economic zone, accelerating the development of this zone, supporting regional industrialization and new urbanization, and establishing a world-class base for phosphorus and phosphate chemical industries.
