Search

As the passenger railway network is expanding and improving, the internal connections and interdependence in the network are rising. Once a sudden geological hazard occurs and damages the network structure, the train service is prone to large-scale halt or delay. A geographical railway network is modeled to analyze the spatial distribution characteristics of the railway network as well as its vulnerability under typical geological hazards, such as earthquakes, collapses, landslides and debris flows. First, this paper modeled the geographical railway network in China based on the complex network method and analyzed the spatial distribution characteristics of the railway network. Then, the data of geological hazards along the railway that occurred over the years were crawled through the Internet to construct the hazard database to analyze the time–space distribution characteristics. Finally, based on the data of geological hazards along the railway and results of the susceptibility to geological hazards, the vulnerability of the geographical railway network was evaluated. Among these geological hazards, the greatest impact on railway safety operation came from earthquakes (48%), followed by landslides (28%), debris flows (17%) and collapses (7%). About 30% of the lines of the geographical railway network were exposed in the susceptibility areas. The most vulnerable railway lines included Sichuan–Guizhou Railway, Chengdu–Kunming Railway and Chengdu–Guiyang high-speed Railway in Southwest China, Lanzhou–Urumqi Railway and Southern Xinjiang Railway in Northwest China, and Beijing–Harbin Railway and Harbin–Manzhouli Railway in Northeast China. Therefore, professional railway rescue materials should be arranged at key stations in the above sections, with a view to improving the capability to respond to sudden geological hazards. [ABSTRACT FROM AUTHOR]

The Jinsha River rail–road double-deck arch bridge (bridge designed to 250 km/h) of the Chengdu–Guiyang high-speed railway (HSR) (designed to 350 km/h) is a complex system with a novel structure in China. The upper deck carries a four-track railway while the lower deck carries a six-lane urban expressway, with a height difference of 32 m. The bridge is located in the mountainous river reach of the city of Yibin. The 336 m main span adopts a high-pier, rigid steel frame, parallel tied-arch structure, built using cantilevers and temporary stay cables with the cable crane method. The 116 m and 120 m side-arches are reinforced concrete, simply-supported, basket-lifting tied-arches built by the mass cast in situ method. The rare layered structure gathers different arch types (top-bared, bottom-bared and half-through arches) into one bridge, which brought significant challenges to its design and construction. Other innovative solutions included flexible hangers passing through rigid hangers for the layered stiffening decks, ultra-high-performance concrete for the steel orthotropic deck road pavement and the use of boat shipments to overcome the scarce availability of flat land at the site. This paper describes some of the salient design and construction challenges of this landmark structure, the world's first double-deck HSR arch bridge. [ABSTRACT FROM AUTHOR]