China News Service, Dali, March 28 (Zuo Xingdong, Zhang Weiming, Wang Peng) After 14 years of hard work by the builders, the Shanyang Tunnel of Yunnan University (Li), Rui (Li) Railway, an important part of the China-Myanmar International Corridor, opened on the 28th. The tunnel is the most difficult and safest railway tunnel under construction in China.
The picture shows that the Shanyang Tunnel of the Yunnan University (Li)-Rui (Li) Railway was completed on the 28th.
Photo by Ma Pengfei
Shanyang Tunnel is located in Yongping County, Dali Prefecture, Yunnan Province, with a total length of 13.39 kilometers. It is located in the Lancang River fault zone and passes through 6 large-scale fault fracture zones in the Hengduan Mountains.
Since the start of construction in 2008, there have been more than 700 geological disasters such as slippage, collapse, mud inrush, and water inrush. Among them, the last 200 meters of surrounding rock have been evaluated as VI level by the domestic expert group, which is the most difficult to excavate the surrounding rock under construction in China. , The railway tunnel with the highest safety risk, the successful construction of this tunnel has accumulated experience for railway construction under similar geological conditions in China.
The picture shows the large-scale machinery in operation in Shanyang Tunnel of the Dali-Swedish Railway.
Photo by Zuo Xingdong
"The tunnel is 1 km away from the top of the mountain. Under the action of high ground stress, the maximum pressure of the tunnel is equivalent to 2,000 tons per square meter, resulting in large deformation of soft rock with a single-point deformation of 1.2 meters and a continuous deformation section of more than 2,000 meters. "Liu Xiangzhen, on-site construction director of the Dari-Rui Railway Project Department of China Railway 23rd Bureau, said, "Even if we used a double-layer large steel arch for support, the huge high ground stress still twisted and deformed the arch, and the same section was replaced when the most It has been arched three times, and the total arch change of the entire tunnel is more than 3,000 meters, which is rare at home and abroad.”
In 2008, as soon as Liu Xiangzhen graduated, he came to the Da-Rui Railway to build the Shanyang Tunnel. It was 14 years in a blink of an eye. The small trees around the tunnel have grown up, and the workers around him have changed one after another, but he has always adhered to the tunnel construction. The hardest place.
For 14 years, more than 5,100 days and nights, tens of thousands of builders, like Liu Xiangzhen, adhered to their ideals, practiced their original aspirations, and fought against complex geological and harsh environments such as water-rich, high-temperature and high-humidity. Many thrilling moments are unforgettable.
The picture shows construction workers working in the Shanyang Tunnel.
Photo by Zuo Xingdong
The surrounding rock of the tunnel is weak and broken. It softens when it sees water, and disperses when it encounters the wind. It is like "pulling holes in tofu". The difficulties involved can be imagined.
The entrance of the tunnel is drained by the reverse slope. Liu Xiangzhen was most impressed when the water gushing out from the advanced horizontal drilling instantly sprayed more than ten meters away. In less than an hour, a stagnant water of nearly 4 meters was formed, which was poured back nearly 200 meters. It took more than a week of continuous rescue to remove the water inrush and sediment. Now that I think about it, I am still very scared.
At its peak, the tunnel's daily water inflow exceeded 38,000 cubic meters, which could fill 20 standard swimming pools. In the past 14 years, nearly 1,500 pumps have been used up by the construction unit.
Affected by bad geology and topography, the tunnel construction can only adopt single-headed excavation from the inlet and outlet ends. The tunnel-type ventilation operation mode makes the single-headed excavation distance of more than 6 kilometers, the air circulation is difficult, and the oxygen content in the tunnel is less than 6.1 %, the humidity is close to 100%, and the ambient temperature of the tunnel face at the front end of the tunnel is kept above 42 degrees Celsius all year round. The environment of high temperature, high humidity and hypoxia always tests the will and physical ability of the builders.
Construction workers had to change shifts every 2 hours, otherwise it would be difficult to support their physical strength.
In order to improve the construction environment, Yungui Railway Company organized the China Railway 23rd Bureau and other participating units to optimize the construction plan, improve ventilation conditions, configure oxygen-absorbing equipment, and transport more than 20 tons of ice cubes into the cave every day to cool the workers.
Facing the risk of large deformation of soft rock, inrush of mud and water, and high temperature and high humidity that may occur at any time, China National Railway Group coordinated and supervised the promotion of tunnel construction, invited experts for consultations many times, and researched and formulated the "anti-slump, deformation control, and prevention measures". The construction strategy is based on the “surging and sudden”.
Yunnan Company of Yunnan-Guizhou Railway organized the China Railway 23rd Bureau and other participating units to tackle the tough problems in the same direction, and adopted the strongest reinforcement and protection measures for tunnel construction in China. Deformation risk.
The picture shows construction workers working in the Shanyang Tunnel.
Photo by Zuo Xingdong
Xiao Hongwu, Chairman, Secretary of the Party Committee and General Manager of China Railway 23rd Bureau, said in an interview, "The safety of tunnels reflects the advantage of concentrating on major events. We mobilized elite soldiers and strong generals, and used overall advantageous resources to tackle the tough problems. The tough battle of Yang Tunnel has ensured the safe and smooth penetration of the tunnel.”
"At present, the subgrade and bridge works of the Dali-Baoshan section of the Dali-Russia Railway are 100% completed, and the station building construction is 95% completed. The accumulative track laying of the main line for more than 100 kilometers is 78% completed, and the 'four electricity' projects such as electricity, communication, and signals are progressing in an orderly manner. "Yan Jiabin, engineer of Yunnan-Guizhou Railway Yunnan Company, said that the Dali to Baoshan section of the Dali-Ruizhou Railway is expected to open within this year.
The Dali-Ruizhou Railway has a total length of 330 kilometers and a bridge-tunnel ratio of 76.5%. It is an important project for improving the road network layout and western development in China's "Medium and Long-Term Railway Network Planning".
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