Sichuan Water Conservancy's first shield to wear the river tunnel -Maoer Minjiang Dian Tunnel Pore

Cover reporter Chai Fengmu

On June 17, with the roar of the machine, the last hard rock layer was quickly divided into debris by the blade of the shield head to the last meter, which marked the control of the first phase of the north of the north of the Jiaba irrigation district. Engineering -The Tunnel of the Maoer Minjiang River is officially connected.

The tunnel is 1352 meters in length and wears the bottom of the Minjiang River at 400 meters. It is the first time in the history of Sichuan water conservancy construction to cross the river and river, and it is also the largest diameter shield machine adopted by the water conservancy industry in the country.

It is understood that the Minjiang section that runs through the Tunnel of the Mao'er Minjiang River is an important waters in the rare and unique national nature reserves of the upper reaches of the Yangtze River. The difficulty and safety risks are great. In order to protect the ecological environment of the Minjiang River, to abandon the risk coefficient and the drilling excavation method of high risk factor and is not conducive to ecological protection from the Jiaba irrigation district. Finally, the advanced process and environment -friendly shield technology have been selected. Guarded the green rivers ecological environment.

The shield machine weighs more than 1300 tons, the length of the whole machine is 135 meters, and the excavation diameter is 9.2 meters. It is currently the largest diameter shield machine used in the water conservancy industry in the country. Ship this more than 1,300 tons of "guys" from Changsha to Yibin. From the modification, transportation, downhole, digging into the river ... every step is a huge challenge. The biggest difficulty in the construction of the Tunnel of the Mao Er River is to wear 400 meters of the Dajiang River. Because the tunnel hole is the shallower of the soil buried at the bottom of the Minjiang River, only 11 meters, the water head pressure under the shield machine is as high as 120 MPa, facing risks such as rotation and permeable cracking layers, and the construction faces a lot of challenges.

To this end, construction units, design units, supervision units, and contractors have invited experts from all parties to jointly demonstrate the construction plan, formulate special measures, and optimize and upgrade the shield machine. The technical excavation can be seamlessly switched by selecting the optimal excavation mode according to the real -time geological situation between different strata to ensure the efficiency of the excavation while taking into account the safety. It is also the first time that the national water conservancy project has used this advanced shield construction technology.

The Maoer Minjiang Dian Tunnel started on September 29, 2021. More than 200 builders lasted more than 600 days and nights. The unfavorable factors such as the blade cake, and finally realized the smooth penetration of the Cat's Minjiang River Tunnel. The smooth construction of the project will have a specific and important reference significance for the construction of the large cave traversal through the river tunnel, and it also lays a solid foundation for the first step of the first phase of the Jiaba irrigation district project.

Extended reading:

The Xiangjiaba Irrigation District Project is a supporting project determined by the comprehensive development and utilization task of the Jiaba Hydropower Station. It is an important part of the province's "five horizontal and six vertical" water diversion and hydration ecological water network projects. It is also one of the 172 key water conservancy projects in the country. In 2021, it was included in the National "Fourteenth Five -Year Plan" and the outline of the long -view target in 2035, and the "Outline of the Construction Planning of the Shuangcheng Economic Circle in Chengdu -Chongqing District".

Xiangjiaba irrigation district project covers 22 districts (counties) in 5 cities in Yibin City, Zigong City, Neijiang City, Luzhou City and Zhaotong City, Sichuan Province. mu. The development task is mainly irrigation, and takes into account urban and rural life and industrial water supply. After the project is completed, it can add 143 cities and towns in the irrigation district (8 of them) and more than 4 million rural population water. Water supply in the city. The total investment of the entire project is about 53 billion yuan, and the planned period is 15 years. It is implemented in three phases, namely the first phase of the Bei Gan canal, the second phase of the Beibei Ganchang, and the south. Two steps are implemented. At present, the first phase of the first phase of the north of the Xiangba Irrigation District is construction.

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