Ludinghe Grand Bridge in Ya’an-Kangding Freeway (Bridge Inspection Vehicle)
Ludinghe Grand Bridge in Ya’an-Kangding Freeway is one of the main control projects of Ya’an-Kangding Freeway. It is a super-long-span steel beam suspension bridge built in high-altitude, high-seismic mountainous areas and complex wind fields. The bridge sits in the valley of Dadu River, whose deck is 239 meters higher than Dadu River. The weather conditions are changeable and the wind field is very turbulent where the wind speed reaches as high as 32.6 m/s. The main bridge is a 1100-meter single-span suspension bridge with a steel-concrete composite bridge system; the main girder is a steel truss girder with a truss width of 27m and a truss height of 8.2m; at the Ya’an bank, there’s the tunnel anchorage and the Kangding bank a gravity anchorage; at both banks, there’s the portal type reinforced concrete main tower based on a drilled (digged) hole cylindrical foundation.
One inspection vehicle is arranged on the whole bridge. The inspection vehicle has functions such as straight-line synchronization, automatic adaptation to gauge errors. It is also capable of maintenance operation and automatic leveling on a 12% slope, by which checking the top and bottom chords of the steel truss are possible on its hoistable platform within.
The bridge inspection vehicle can perform full coverage inspection on the top and bottom chords of the steel truss, bearings and its outer surfaces at the same time with high efficiency, while it minimizes the number of inspection vehicles to be arranged to the greatest extent and reduces the construction cost reasonably.
Ludinghe Grand Bridge in Ya’an-Kangding Freeway (Expansion Joint)
Ya’an-Kangding Freeway leads to the Tibetan area in West Sichuan. It is an important part of the horizontal Freeway G42 “Shanghai-Chengdu” and the connecting Freeway G4218 “Ya’an-Yecheng” in National Highway Network Planning, as well as an important section of Chengdu introduction line “Chengdu-Ya’an-Batang-Tibet” and the horizontal line “Kangding-Ya’an-Luzhou-Chongqing” in Sichuan Provincial Highway Network Planning. The route, at a total length of about 135 km, wriggles along G318 corridor and rivers, and travels through Ya’an City, Tianquan County and Luding County.
Ludinghe Grand Bridge, a 1100-meter span suspension bridge, is located in Luding County, Ganzi Prefecture. Its main bridge and approach bridge both use a 2000 unit-type multi-directional displacement comb-shaped expansion joint at the intersection, each 24.5 meters long and totally 49 meters.
Ludinghe Grand Bridge in Ya’an Kangding Freeway utilizes the 2000 mm displacement unit-type multi-directional comb-shaped expansion joint independently developed by our company. So far, it is the expansion device of the largest displacement applied by Xinzhu.
Its application features are:
1. The spherical bearing at the bottom is able to meet the rotation requirement of a bridge above 0.05 rad.
2. The main bearing component tooth plate adopts high safety factor, which greatly improves the loading capacity of the structure and hence has a long service life.
3. It uses special installation processes which allows good flatness, high driving comfort and low noise, by which it receives unanimous praise from the proprietor and road management & maintenance departments.
Ludinghe Grand Bridge in Ya’an-Kangding Freeway (Bearings)
Ludinghe Grand Bridge in Ya’an-Kangding Freeway is located in Daduhe Gorge in Ganzi Prefecture. It is a suspension bridge built in the environment where there’s high altitude, high seismic intensity zone and complex wind field. This grand bridge is completed and opened in December 2018. It has a total length of 1,411 meters and a main span of 1,100 meters, which costs more than 1 billion RMB. It is a control project of Ya’an-Kangding Freeway, the artery into Tibet from Sichuan, also the path of life crossing Lu Mountain and Kangding earth-stricken areas. It creates the “two firsts”— it is the largest span steel truss suspension bridge under construction in Sichuan and Tibet, and it is also the world’s longest tunnel-type anchorage under construction. It also has “five first times”— for example, the first time in Sichuan Province that a drone is used to draw a pilot cable across the river, and the first time in China that a cable hoisting system is used to erect a kilometer-level steel truss beam in high-altitude canyon and complex strong winds. All of which marks it the “super project” in China’s highway industry.
Xinzhu patented products applied – loose cable saddle support, tension and compression type support, and elastic horizontal wind resistant support. Loose cable saddle support largely improves the stress condition of the base and reduces the construction difficulty; the tension and compression type support and the elastic horizontal wind resistant support can reduce the impact of the bridge on the tower by the cross wind, hence increases the life of the support and reduced the later cost.
