It took two years to attack the large deformation technology of the soft rock of the Changning Tunnel!The party members of the Changbao Expressway Project Department are doing this ~

The Changning Tunnel of Changbao (Changning-Baoshan) in Yunnan (Changning-Baoshan) is one of the key projects of the "Sanqiao and One Tunnel" of Guangxi Road and Bridge Engineering Group Co., Ltd., a company directly under the Guangxi Beibu Gulf Investment Group, and is also the "card neck" project of Changbao Expressway. The tunnel is 5.4 kilometers long, and the geological hydrological conditions are complicated, with a maximum buried depth of 456 meters. During the construction process, it was affected by a series of geological disasters such as asymmetrical soft rocks, pouring water, mud, and collapse. The biggest difficulty.

In order to solve the difficulties of the weak and broken siege rock tunnel, in 2019, the party branch of the Changbao Road area set up a party member's corporation team to launch an attack on the difficulties of construction. They actively challenged the blank scientific research of asymmetric high pre -tightening force, which made the key technologies and construction experience of the large deformation control of the soft rock tunnel in Yunnan Province from scratch, from weak to strong, and to promote the highway tunnel of the mountainous area of ​​my country. The development of engineering construction technology provides experience support and technical support.

The maximum deformation of the surrounding rock is reduced from 2125 mm to less than 300 mm, the conversion rate is reduced from 33%to 0, and the average daily feet increase from 1.2 meters per day to 1.6 meters. Every breakthrough in the long construction journey is inseparable from the oath of the party.

——It seemingly one step away, but it is the end of the world -

From the high altitude of 6000 meters, overlooking the horizontal mountainous area of ​​western Yunnan, the mountains and mountains can shoulders, and the peaks are rushing to the valley. This is the "bottleneck" area with the most difficult construction, the highest engineering risk, and the most complicated geological conditions in China. The Changning Tunnel located here is the "card neck" project of Changbao Highway in Yunnan Province. Broken belt development, groundwater development, and surrounding rock strength stress ratio is less than 4, which is a typical high -ground stress soft rock tunnel.

Under the complex and changeable geological conditions, the surrounding rock of the Changning Tunnel is like a maniac beast, which is elusive: the initial support steel arches are easily distorted, deformed, sprayed concrete cracks, and the pieces are severe, which can easily lead to restrictions. At the site, only measures such as changing arch were replaced or arched, and the quality, safety and progress were severely restricted by the quality, safety and progress of the project.

"One step of the Changning Tunnel is actually the end of the world." In the memory of the party members of the Changning Tunnel, this experience is particularly profound: During the construction of July 2018 to December 2020 The deformation limit causes 422 meters to change the arch, and it takes about 400 days to change the arch.

"Only by vigorously promoting scientific and technological innovation and accelerating key core technologies can we play a good first chess and active battles, can we turn danger and danger into the opportunity." In 2019, project secretary and project manager Yang Kang led the party members' technical research team to start solving solutions The innovation path of asymmetric soft rock deformation problem. Among the team members, the post -85s and post -95s have become the main force.

——The flowers of our flowers are the success of scientific and technological achievements--

After querying a large number of domestic and foreign data and visiting multiple tunnels on the spot, the technical team invited Academician He Manchao and his scientific research team to conduct technical exchanges on the weak deformation of the Changning Tunnel. In the construction of Changning Tunnel.

Can this become the "golden key" to solve the large deformation of soft rocks? Is it applicable to Changning Tunnel? Choosing to try may take huge costs.

At the time of the exhibition, this party member who was only 26 years old was determined to fight against the water, analyzing the deformation mechanism of tunnel surrounding rocks day and night, and established a thin -layered soft rock tunnel structure mechanics model, analyzed the deformation of the deformation of the thin -layer soft rock tunnel deformation. Control factors. After experiencing countless attempts and setbacks, the detained team finally proposed the asymmetric high pre -tightening support plan based on the circumstances of the enclosure asymmetric deformation.

The hard -to -end pace has never stopped, and the research team has carried out research on large soft rock deformation damage model tests and NPR anchor cord control technology according to the plan. On the day after the test, they are young, and there are few flowers in the previous month, and they are mostly overwhelming. Zhang Yafei, deputy chief worker, lamented, "Our flowers are good for the success of scientific and technological achievements, and converted into a new engine for tunnel construction."

—— Write the paper on the soft rock ———

To carry out the research of the NPR anchor cord support technology, it means that it is necessary to face the "mania" of the large deformation of soft rocks, and it also means the hardships and unpredictable risks of water and fire.

Entering the test stage, the relevant team selected 100 meters on the right hole of the Baoshan end of the Changning Tunnel to construct a 100 meters according to the NPR anchor cable coupling support design scheme in the tunnel large deformed section. As the youngest party member in the team, he stayed in a high temperature, high humidity, and dusty tunnel for 5 hours.

Gao Heng's stress -stress anchor cable needs to be drilled and expanded before installation. After installation, you need to apply prestressing the anchor cable. During the process, strong and continuous noise will be generated. Technician Liu Nengyuan always records it to ensure the collection of on -site monitoring data collection The integrity, which makes hearing sensitivity. "Turning around means missing a certain detail, it is likely to affect the quality and safety of the tunnel construction, and it cannot be ignored every moment."

"Our goal is to write the paper on the soft rock." Yang Yi, the chief engineer of the project, said that the construction environment was difficult and bad, but this group of young people united into a rope to gather wisdom. In just a few months, the troops have verified the reliability and implementation of the support scheme through the measured surrounding rock deformation, steel arch pressure, and anchor cable force.

In April 2021, the NPR anchor cable control scheme was officially put into use in the Changning Tunnel. This is the first time that the NPR anchor cable active support technology is applied to the soft rock tunnel project under the complex geological conditions under the complex geological conditions of Western Yunnan Yunnan in Yunnan. Key technical problems. Relying on technological achievements, the troidee team establishes a system of soft rock large deformation control technology to form a complete set of prestressed anchor network spray support construction process and construction method, becoming the dazzling dazzling of the treasure house of my country's highway tunnel support technology. Star.

—— "Move in" tunnel of the party member activity room--

"Changning Tunnel Party Banner Red." For this group of young people, red genes have long been integrated into red blood, and not forgetting the original intention is the spiritual password that supports them to go forward. They "moved into" the muddy tunnel of the party members' activity room, and carried heavy measurement instruments in their hands. In a humid and humid environment, they used cheers and shouts to communicate with high pre -tightening force. Effect.

Under the leading role of party members' pioneer model, the project 9 submitted to the party's application for the party. Liu Nengyuan wrote in an application for the party: "Whenever the mud dots at the depth of 253 meters sprinkled on the flashing party emblem on their chest, whenever the deepest part of the tunnel was seen, the party flag was bright and bright as the sun. When the previous pair of resolute and pure eyes, the youth and love of the Communist Party members. It turned out that it was not easy to tame a 'beast'. , Contribute everything to the land of Yunnan, contribute everything to the motherland ... "

This group of young people is ambitious and has a big self. In scientific research practice, they have become talented. The project party branch was awarded the "Pioneer Beitou · Three Years Leap" Pioneer Party Branch. The project was awarded the advanced collective of Guangxi Road and Bridge Group in 2021. Continue to aim at the "card neck" technical difficulties of high -ground stress soft rock transformation tunnels and special highway tunnel construction. "

Source: Spring City Evening News Author: Huangzhi Shaoyang Jun

Editor: Wang Donghua | Responsible editor: Wang Donghua

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