Achieve a breakthrough
Lao Anshan Tunnel is located in Foping and ningshan county, Shaanxi Province, with a total length of 15 16 1m, which is the second extra-long tunnel of Xicheng Passenger Dedicated Line. It is the key and difficult project of Xicheng Passenger Dedicated Line, and it is also one of the six first-class risk tunnels in the whole line. Construction started on April, 2065438 19.
On September 9, 2065438 19, after 29 months' efforts, the Lao Anshan Tunnel, the key control project of Xi 'an-Cheng Passenger Dedicated Line, was successfully completed, becoming the first super-long high-speed railway tunnel to successfully cross the Qinling Mountains.
Construction situation
difficulty
Lao Anshan Tunnel is located in the low mountain area at the southern foot of Qinling Mountains. The entrance of the tunnel is located in Buyu Changgou, Chaijiaguan Village, Simidi Town, ningshan county, and the exit is located in Dongyuedian Village, Dongyuegou Village, Foping County, with an average elevation of 825 ~1990 m. Due to the complex geological conditions of rock strata, abundant groundwater, the surface of the tunnel body fluctuates greatly, and there are many "V"-shaped erosion gullies in bedrock, which makes the construction difficult.
During the construction of the tunnel with broken rock mass, there have been many adverse geological disasters, such as rockburst and sudden (gushing) water, and the maximum gushing water is 43,875 cubic meters/day.
Countermeasures
In view of the complex geology and landform, China Railway No.12 Bureau, which is in charge of tunnel construction, adopts "full-face method" to carry out smooth blasting in the second and third grade surrounding rock sections; In the rock burst area, the method of drilling prestressed release holes combined with sprinkling water to cool down in time is adopted to realize "weak explosion and fast propulsion". In the areas with serious water gushing and surrounding rocks of Grade 4 and 5, advance geological prediction is carried out, support is strengthened, and "zero accident" breakthrough of the tunnel is realized. In addition, according to the designer of Tieyi Hospital, because the tunnel exit is connected with the newly-built Foping Station, the maximum cross section of the tunnel entrance has reached 250 square meters. Considering safety, the tunnel also has an emergency shelter for passengers to evacuate after disasters and accidents.
Important significance
Xi 'an-Chengdu Passenger Dedicated Line is located in the south of Shaanxi Province and the north-central part of Sichuan Province, passing through Qinba Mountain area and connecting Guanzhong Plain, Hanzhong Basin and Chengdu Plain. It starts from Xi in the north and enters Sichuan via Hanzhong in the south. The total length of Xi 'an-Chengdu line is 643 kilometers, of which Xi 'an-Jiangyou section is a newly-built passenger dedicated line with a total length of 5 10.5 kilometers. Jiangyou and the opened Mianyang-Chengdu-Leshan passenger dedicated line are connected to Chengdu, with a speed target of 250 km/h. The project is 343.6 kilometers in Shaanxi (from xi 'an North Station to the provincial boundary), and the construction period is 5 years. After the completion, Xi to Chengdu will form a three-hour economic circle.
For more exclusive information about the construction industry, please pay attention to the micro-signal of the construction network in real time.
For more information about bid writing and improving the winning rate, click on the bottom customer service for free consultation.