Beipanjiang Railway Bridge Qinglong

The Beipanjiang River is a barrier that seems to require engineers to create world record bridge spans. This tradition began in 2001 when the first record breaking high railway arch crossing took place near Fa’er Bouyei with a rail to river drop of 275 meters. Things have changed a lot in China between 2001 and 2015 and most of the newer railway lines are being designed and built for high speed trains reaching speeds of 250 kilometers an hour.

The massive Beipanjiang River railway arch is not only the world's highest railway bridge at 283 meters if you exclude Najiehe which is over a reservoir, but is also the world's longest concrete arch ever built with a span of 445 meters. The crossing is the crown jewel of bridges on the high speed railway line connecting Guiyang and Kunming. Located north of Qinglong city, the Beipanjiang has always been Guizhou's second greatest river after the Wujiang.

Designed to carry trains that will reach speeds of 250 kilometers an hour, the 721 meter long crossing has a main arch with a rise of 100 meters and a rise to span ratio of 4.45. The arch ring cross section has three cells within a single-box with equal depth of 9 meters and a variable width of 18 to 28 meters. The width of the arch at the springing is 28 meters while the width of the arch at the crown is 18 meters. Double-column framed piers are used for supporting the deck. The piers rise 102 meters at the abutments with the tallest spandrel column on the arch rising 59 meters. Steel tubular trusses filled with concrete were used as a skeleton during construction before it was encased in concrete. The stay cables placed at the abutment pier were post-tensioned step by step during the concrete-pouring to assist the skeleton in load carrying.

The approach bridges are 5.6 +32 +2x65 +4x42 +4x42 +2x65 +2x37 +6.6 meters prestressed concrete continuous beams. The dual line width of unballasted track is 4.6 meters wide and crosses the Beipanjiang River just below the Guangzhao Dam.

The deformation of the arch ring increased gradually as the volume of arch ring concrete increased during the construction process. The maximum deflection was designed to be 294mm after pouring of the arch ring concrete was completed and 383mm after the additional dead load was placed. Because live load accounts for a small proportion of dead load, precamber of the arch ring is designed based on the deformation caused by dead load. At the arch crown, the precamber of 350mm is set, while the cambers of other parts of the arch ring are distributed by quadratic parabola. Under the standard railway live load, the maximum upward vertical deflection is 40.2mm which occurs at the quarter-span section and the maximum downward vertical deflection is 48.8mm which also occurs at the quarter-span section. Under the lateral wind load, the maximum lateral displacement is 52.8mm which occurs at the mid-span section.

The bridge is located at kilometer 882 and cost 430 million Yuan or 66 million dollars. The Beipanjiang Railway Bridge is a sister bridge to the slightly smaller Nanpanjiang Railway Bridge near Qiubei, Yunnan as they were both designed by the same engineering teams with similar designs and construction methods. The major difference between the two spans is the Beipanjiang Bridge arch rib has a depth of 9 meters while the Nanpanjiang arch rib has a depth of 8.5 meters.

Beipanjiang Railway Bridge Qinglong Elevation

The span of steel tubular truss is 445m. It is longitudinally divided into 40 segments for lifting and the length of each segment is 12m. The truss is made of the upper and lower chords of 8 steel tubes with a diameter of 750mm and a thickness of 24mm.Image by Eric Sakowski / HighestBridges.com

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