Yingjing, Sichuan, China
623 feet high / 190 meters high
656 foot span / 200 meter span
A sister bridge to the nearby Labajin crossing, the similarly designed Heishigou Bridge also uses a unique concrete pier design that the Chinese developed for just 3 large bridges on the Yaxi highway. The third bridge to use this first-ever technique is the Tangjiawan Bridge.
Although the two main piers of Heishigou Bridge are not as tall as those on Labajin, they are still among the world's tallest at 155 meters. The concept behind the SRC or steel reinforced concrete column is to combine the shear-wall strength of concrete but retain steel tubes for cross bracing and to maintain the skeletal strength of the piers to meet seismic requirements of bending and flexibility. The optimum height level for each concrete pier section was 12 meters which was partly determined by the weight of a 12 meter steel column which has a weight of 30 tons. The concrete is placed on both the outside and inside of the steel tubes making for a steel and concrete sandwich. At each 12 meter interval there is a flat concrete deck that gives the 4 walls rigidity. The two parallel piers are 13.8 meters by 6.8 meters at the base and taper to 10 by 6.8 meters at the cap. The 5.6 meter gap between the two parallel piers are connected by steel truss tubes.
The G5 Yaxi highway also has several impressive tunnels including the 10 kilometer long Daxiangling mud mountain tunnel with a maximum depth of 1650 meters with more then 5 kilometers of that length over 1000 meters deep.
Heishigou Bridge Elevation
Heishigou Bridge pier design.
Drawings of the unique pier frame design.
Heishigou Bridge pier foundation design.
The base of Labajin Bridge which uses the same exact pier design as Heishigou Bridge with steel tubes at all 4 corners.
Heishigou Bridge satellite image.
Satellite view of Heishigou, Labajin and Shizijinghe Bridges on the G5 expressway. Not shown is the Tangjiawan Bridge further to the south which also uses the unique steel reinforced concrete column tubes. The Shizijinghe Bridge was built with conventional concrete-only piers that are on nearly every other high beam bridge in China.
Location map of Heishigou, Labajin and Shizijinghe Bridges. Tangjiawan Bridge is just off the map to the south.
Yaxi Expressway Map.