40000 tons of steel cable lifting for the world's largest span suspension bridge in mountainous areas

The Jinsha River is the upper reaches of the Yangtze River, flowing through four provinces: Qinghai, Tibet, Sichuan, and Yunnan. The flow is steep and the river is breathtaking

The Jinsha River is the upper reaches of the Yangtze River, flowing through four provinces: Qinghai, Tibet, Sichuan, and Yunnan. The flow is steep and the river is breathtaking. Mao Zedong's poem "The Seven Laws of the Long March" includes a sentence: "The Jinsha River is warm against the clouds and cliffs, while the Dadu Bridge is cold with iron ropes." Here, "Jinsha" refers to the Jinsha River.

Just between the steep mountains of the Jinsha River Canyon, Chinese engineers have erected a suspension bridge with a span of 1386 meters - the Jinsha River Bridge in Jin'an. What is the significance of the emergence of the suspension bridge with the largest span in the world's mountainous areas?

Jin'an Jinsha River Bridge | Creating 4 World First Bridges in Bridge History

The Jinsha River Bridge in Jin'an is located in Lijiang, Yunnan. It is a river crossing passage connecting Yongsheng County and Gucheng District, with cliffs on both sides. The bridge deck is 335 meters higher than the river surface, equivalent to 110 floors high.

It is reported that the bridge is composed of 128 steel truss beams assembled, with a single steel truss beam weighing 216 tons. The "lifeline" that carries the weight of the bridge - the two main cables are composed of 42000 high-strength galvanized steel wires, with a total length of 87000 kilometers, which is enough to circle the Earth twice.

The Jinsha River Bridge in Jin'an is equipped with two main cables, each with a length of 2046 meters and consisting of 169 cable strands. Each cable strand is also composed of 127 high-strength galvanized steel wires

The Jinsha River Bridge in Jin'an took 4 and a half years from construction to operation, creating 4 world firsts in bridge construction history, including the world's largest span suspension bridge in mountainous areas; The world's first full bridge to adopt the full penetration welding process of U-ribs; The ratio of bridge width to span reaches 1:51, ranking first in the world; The steel truss beam hoisting system has a span of 1386 meters, making it the world's largest span cable crane in the field of bridges.

Jin'an Jinsha River Bridge | Located in the "Three High Areas" and encountering technical difficulties during construction

Behind setting world records, the engineering difficulty is also greater. The Jinsha River Bridge in Jin'an is located in the "three high areas" of "high altitude, large altitude difference, and high earthquake intensity". In addition, the harsh climate conditions make modern bridge construction techniques and top-notch equipment useless.

According to the project manager of the bridge project, the winding mountain roads, nearly vertical mountains, and dense jungle make it impossible for modern machinery to enter and can only be constructed using the most primitive methods. The workers were tirelessly excavating on the cliffs of the mountains, and it took nearly 9 months to create a safe working platform for pile foundation construction.

However, ultra-high strength rock formations pose new technical challenges for construction. After on-site exploration, the maximum strength of the layer rock exceeds 330 MPa, which is much more difficult than expected. The construction team has made multiple adjustments to the plan and ultimately decided to use the traditional method of "manual blasting+rotary drilling excavation" for construction. Little by little blasting, layer by layer excavation, and day by day advancement, 64 pile foundations totaling 3168 meters long were finally completed in 3 months.

Jin'an Jinsha River Bridge | "Flying Over" Canyon from 1 hour to 1 minute

The deck of the Jinsha River Bridge in Jin'an is a two-way four lane expressway with a design speed of 80 kilometers per hour.

The design speed of the Jinsha River Bridge in Jin'an is 80 kilometers per hour. After its opening, it used to take one hour to drive down the valley and climb the slope, winding through hundreds of bends in the Jinsha River. Now, it only takes one minute to "fly" over the Jinsha River from a height of 335 meters.

In addition, the Jinsha River Bridge in Jin'an is also a control project of the magnificent expressway. After the completion and opening of the Huali Expressway, the travel time from Lijiang, Yunnan to Panzhihua, Sichuan will be reduced from the original 6 hours to 2 hours. It plays an important role in promoting the development of the northwest region of Yunnan, poverty alleviation, and driving the development of tourism and other industries, benefiting over 1.1 million people along the route.

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