Recently, a major breakthrough has been made in the construction progress of the whole line of the Central Yunnan Water Diversion Project in Yunnan Province. The total excavation of the Central Yunnan Water Diversion Project has reached 381.8 kilometers, accounting for 50.5% of the total construction mileage of 755 kilometers.

At the construction site of the Longtan Tunnel in Chuxiong Yi Autonomous Prefecture, workers are working together to speed up the construction. The Longtan Tunnel is 14,037 meters long. The terrain along the line is undulating, and it passes through many geological faults. In addition, the water inflow during the tunnel excavation process is severe, the construction conditions are severe, the risk is high, and the difficulty is high. According to the relevant person in charge, since the start of construction, there have been more than 10 dangers of landslides and water gushing at the construction site. The construction personnel adjusted the construction method in a timely manner, and multiple working faces were constructed simultaneously. 76 people are divided into 3 shifts 24 hours a day, and the construction work is uninterrupted. Since the Spring Festival, the tunnel excavation has exceeded 200 meters.

There are 58 tunnels with a length of 611.99 kilometers, and the remaining part is constructed by inverted siphon.

Inverted siphon is a kind of interchange hydraulic structure that is often used when the channel intersects with the road or river or when the channel crosses the valley. After the foundation is done, the tunnels at both ends are connected by water pipes. At the Guanyin Mountain inverted siphon construction site, construction workers are hoisting penstocks with large cranes. In order to improve efficiency, these large penstocks are processed at the construction site.

The relevant person in charge introduced that each of the steel plates required for these pressure steel pipes is customized and processed and assembled after being transported to the site. According to different head differences, the minimum wall thickness of the steel plate is 16 mm, and the maximum is 28 mm. Now, this work area can open two working faces a day, and can install 6 sections of penstocks every day.

After the project is completed, water can be diverted from the main stream of the Jinsha River, which is relatively abundant in water, to the central Yunnan area, so as to alleviate the contradiction between urban production and domestic water consumption in the central Yunnan area, and promote the sustainable economic and social development of Yunnan.

The difficulty of the construction of this project is unimaginable for ordinary people, because the area through which the Central Yunnan Water Diversion Project passes is a living "geological museum", which has created "six best in the world" and broke "ten world-class technical problems".

The six best in the world

●The longest water tunnel in the world

●The world's largest underground pump room

●The diameter of TBM is the largest of its kind in the world

●The single centrifugal pump capacity of the lifting pump station is the largest in Asia

●The total installed capacity of the pumping station is the largest in Asia

●Geological conditions are the most complex of similar projects in China

Top 10 world-class technical problems

1. The design and construction of the pumping station is difficult

2. Deep buried tunnels are widely distributed

3. The impact of groundwater is difficult to deal with

4. There are many broken faults

5. The large deformation of soft rock is prominent

6. High seismic intensity

7. Hard rock rockburst construction is difficult

8. There are many toxic and harmful gases

9. Highland temperature and heat hazards are serious

10. High TBM design and manufacturing process

Construction site in Biaofengtun Tunnel of Chuxiong Section 2

In order to ensure the completion of the project on time and with high quality, scientific and technological assistance is essential, and "super equipment" escorts the water diversion project in Central Yunnan.

"Super equipment" - "Longxiang" shield machine

The world's largest diameter full-section hard rock tunnel boring machine (TBM) "Yunling" commissioning and excavation started

The construction of the water diversion project in central Yunnan is still in full swing. Let us look forward to the water from the Jinsha River to moisten the land of central Yunnan soon.Editor/Ma Xue