Daban mountain

Daban mountain is located at the junction of Datong County and Menyuan County in Qinghai Province, which is the main traffic route from Qinghai to Gansu. This is one of the three best places to watch rape flowers in Menyuan, about 30 kilometers away from Haomen town. When it comes to the season of rape blossom, it's also a good choice to come here to see the rape flowers all over the mountains. The viewing platform here is a big parking lot. Don't park your car on the side of the road. When the Dabanshan tunnel near it was completed, it was the highest elevation of the road tunnel in Asia at that time.

Daban mountain

Daban mountain (Daban: Mongolian, meaning Shankou; Shanling) is located at the junction of Datong and Menyuan counties in Qinghai Province. It is an important traffic route from Qinghai to Gansu. Among the numerous mountains in Qinghai Plateau, Daban mountain is only a small generation, but its special geographical location makes Daban mountain famous in the plateau. The valley areas on the north and south sides of Daban mountain are relatively high above sea level.

Daban mountain

Low temperature, cool climate, Qinghai is an important agricultural and animal husbandry areas, especially in the north of the wide Haomen River Valley, all planted with small rape, become the famous hundred Li flower sea. Datong County in the south is an important spring wheat production base in Qinghai Province. The scenery of Baoku gorge, Chahan River National Forest Park and Heiquan Reservoir in the south is charming.

Dabanshan tunnel

GPS of Dabanshan tunnel: 37.344232101.40211337.347405101.404324.

geographical position

The Xizhang road was the Xiping Zhangye road of the South Silk Road in ancient times. Since the Western Han Dynasty, it has experienced many vicissitudes and has been abandoned several times. After the founding of the people's Republic of China, it has been transformed into a national highway from Qinghai to Hexi Corridor, connecting the Eurasian road and bridge. Daban mountain is a vein of the Qilian Mountains. It is steep and towering. The elevation of the pass is 3940 meters. Daban mountain road is built along the mountain, and the route is tortuous. Daban pass extends to yinpo for three kilometers. In winter and spring, it is covered with snow and ice. It often encounters avalanches and ice collapses. The folk song says, "the gate of hell is no more difficult than Daban in the snow.".

Dabanshan tunnel is located in the mountain crossing section from k104 to k109 of national highway 227. In May 1993, the Ministry of Communications approved the feasibility study report of Dabanshan tunnel project, and in 1994, the Ministry of Communications approved the preliminary design of Dabanshan tunnel with jiaogonglu fa (1994) No. 578. The total length of the tunnel is 1530m, and the lead wires at both ends are 2852m; the tunnel and two lead wires are designed according to the technical standards of class III Highway in mountainous and hilly areas: the net width of the tunnel is 8.5m (i.e. 7.0 + 0.75 × 2), the net height is 4.5m, the width of the subgrade at both ends is 8.5m, and the width of the pavement is 7m; the bridge and culvert load adopts the technical standards of qi-20 and hang-100; the basic seismic crack is 7.8. The approved estimate of the project is 128.5671 million yuan, and the adjusted estimate approved by the Ministry of communications in 1998 is 155.7276 million yuan, including 110 million yuan subsidized by the Ministry of communications, 46 million yuan raised by Qinghai Province and 10 million yuan loaned by domestic banks.

Top five in the world

Dabanshan tunnel of Xining Zhangye highway in Qinghai Province, which was constructed by No.1 Office of China Railway 16th Bureau, has created five greatest projects: first, the elevation of the road surface center at the south entrance of the tunnel is 3792.75 meters, which is the highest elevation of the road tunnels built in Asia at that time; second, among the road tunnels built in China, the thermal insulation layer is first laid to prevent frost heaving; third, among the road tunnels built in China, the tunnel is the first in the East The fourth is the first long highway tunnel in Qinghai; the fifth is the first bidding for domestic construction units in Qinghai highway infrastructure construction, and the implementation of "FIDIC" management project in line with international standards. The scientific research achievements of Dabanshan tunnel construction project were then extended to the construction of Qinghai Tibet railway, and good results were obtained. It marks that the construction technology of high altitude tunnel in China has reached the international leading level, and has become a great feat in the development of Western China

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To ensure the decoration quality of Dabanshan tunnel and meet the needs of operation in alpine region is the primary problem of tunnel construction in alpine region. However, due to the flying snow in Daban mountain area in four seasons, the annual average temperature is - 3.9 ℃, the extreme low temperature is - 34 ℃, and the annual precipitation of 840 mm, it is very easy to form a freeze-thaw circle around the tunnel. If the tunnel repeatedly freeze-thaw, it will damage the strength of reinforced concrete, causing collapse, water leakage, and even early damage. How to prevent tunnel frost heaving under such high and cold temperature? At that time, there was no successful precedent at home and abroad, which was a new worldwide issue to be tackled.

The "research group of Alpine tunnel" of the 16th Bureau of China Railway Co., Ltd. has carefully learned and digested the successful experiences and lessons at home and abroad. After hundreds of continuous tackling and experiments, it has successfully designed a series of tunnel antifreeze and heat preservation construction schemes with the ingenious combination of "heat preservation and drainage" of Dabanshan tunnel, which has been unanimously recognized by experts of Chinese Academy of Sciences and Qinghai Provincial Department of transportation. They excavated an auxiliary tunnel 5 meters below the main tunnel to drain away the ice and snow water around the tunnel and prevent it from seeping into the tunnel. In order to ensure that the water drainage is exhausted, geotextile, rubber drainage board, glass fiber reinforced plastic waterproof board and other waterproof measures are adopted around the tunnel to wrap up the 1.53 km long tunnel like a person wearing a cotton padded jacket. In addition, polyurethane and dry silicate thermal insulation layers are paved on the surface of the tunnel, and computer-controlled wind proof and thermal insulation doors are installed at both ends of the tunnel. This new design, which integrates large and small tunnels, wind proof, heat preservation and drainage in one furnace, has been listed as a model of plateau tunnel construction by Chinese Academy of Sciences. It is not only unique in China, but also the first in the world.

Address: the junction of Datong County and Menyuan County, Qinghai Province

Longitude: 101.4021419829

Latitude: 37.3523011912

Tour time: 1 hour

Traffic information: [charter]

It's about 500 yuan a day from Xining to Menyuan. If you charter a car in qingshizui Town, it's 200-300 yuan / car, including 4-5 scenic spots

[CMB]

Xining Menyuan County (Haomen town)

At Xinning bus station in Xinning, there are more than ten buses to Menyuan County every day, the whole journey is about 3 hours, and the ticket price is about 40 yuan per person. The consulting telephone number of Xinning bus station in Xining is 0971-6155795

[self driving]

Self driving people can enter Menyuan from all directions (Datong, Qilian, Zhangye) to visit the sea of rape flowers, and each road can be called a landscape highway

Ticket information: Free

Opening hours: all day

Chinese PinYin : Da Ban Shan