"Longquan" together "drink" Jinshui -China Railway Five Bureau Dynasties Drimination Project in Dynasties of Dynasties in Longquan Polybans in Longquan

Wen Jiang Liping Lei Bo Wang Zhongtian

On June 21, "I have been connected! I am through!" As the builders cheered, 690 day and night struggle, the national key water conservancy project in China Railway Five Bureau was successfully connected by the Longquan Injection Tunnel in Central Yunnan.

The water diversion project in Central Yunnan is the iconic project in the 172 water conservancy projects determined by the State Council. It is the largest people's livelihood and well -being project in Yunnan Province. It is also the largest water conservancy project undertaken by China Railway. After the project is completed, the dry flow of the Jinsha River with relatively abundant water volume can be diverted to central Yunnan, alleviating drought in central Yunnan, improving the ecology and water environment of the river and lake in the area, benefiting millions of people. develop.

Great Power Heavy Instrument "Longxiang" helps

Longquan inverted siphon tunnel belongs to one of the 25 flooding siphon -in -water water buildings in the water drainage project in central Yunnan, with a total length of 5071.69 meters. The main urban area of ​​Kunming is the only project in the urban area. This is the only project in the entire line using the shield method, and it is also the first time in the construction of water conservancy projects in Yunnan.

The pipelines above the Longquan inverted siphon tunnel in the main urban area are densely distributed, and there are many surrounding buildings, especially the Kunming Metro Line 2 and Panlongjiang. They have high requirements for construction settlement control and large risks through construction. The geology of this section is complicated, there are full sections of the windstroke and upper soft and hard strata, sand egg gravel, clay, peat land, etc., and there is no vertical well in the middle. The maximum buried depth is 83 meters.

In order to adapt to special geological conditions in the urban area, the shield method was constructed in this section. After receiving the notice of winning the bid, the 4th bidding project department of the Kunming section of the Central Railway Fifth Bureau in the Central Railway Fifth Bureau immediately organized experts to demonstrate and review the shield machine selection. According to the design of the outer diameter of the designed pipe, 6.47 meters of the outer diameter of the blade is determined; through repeated numerical simulation, the structural form and maximum thrust of the shield machine knife plate are determined. The characteristics of the high -distance excavation of 5071 meters in the interval are proposed to many targeted designs of blade and knife anti -wear.

"The" Longxiang "shield machine is tailor -made for the characteristics of Longquan's inverted siphon 'ultra -deep burial and small radius'." Gong Zhenyu, deputy manager of the project, said, "Compared with other composite soil pressure balance shields The machine, the "Dragon Xiang" shield secret sealing waterproof pressure, the main shaft resistance hydraulic ability is 2 times the conventional shield machine, the shield seal uses 4 shield tail brushes, which can withstand 100 meters of water head pressure; Using active hinges can adapt to the excavation conditions of the continuous curve of the 300 -meter radius, which can greatly save time and improve efficiency. "

The "Longxiang" shield machine has a maximum thrust of 4086 tons, the fastest advance speed of 80 mm/min, a total power of 1975 kilowatts, and a minimum turn radius of 250 meters. It has a diameter of 40 mm expansion capabilities. The tunnel engineering has the characteristics of complete function, advanced technology, stable excavation, and strong adaptability. Since the start of the "Longxiang" shield machine on August 1, 2020, it has overcome the long -distance excavation efficiency, the full section of the lust and the hard strata control the difficulty of sinking, the long -distance composite stratum digging into the shield. During the problem of large wear, large -scale deep water pressure, shield construction risks such as large -scale wear, large -scale deep water pressure location, etc., which have achieved "zero pollution" and "zero sedimentation" under Panlongjiang, Panlongjiang Bridge, and Kunming Metro Line 2 and other major major. Risk source. At the same time, the construction unit turns through the three 300 -meter radius curves in a row to excavate the precision control of the shield machine to dig the posture to ensure that the quality of the pipeline and the construction axis has no deviation. Shield construction record.

Taming "Dragon" master is excellent

The Longquan inverted siphon project was buried at dozens of meters underground, and the deepest part was 83 meters from the surface. Ultra -deep burial also leads to the water pressure and large soil pressure around the "Longxiang" shield machine. Once the shield machine is stopped normally, it is easy to cause the shield tail brush of the outer water to protect the shield tail. The injected mortar flows into the shield machine through the gap between the shield tail, which will not only affect the grouting effect, but also cause the tube of the shield tail to displacement and deformation, and the strata sink.

To this end, the project department has organized a technical seminar for many times, strictly connected the construction process, and moderately increased the "Longxiang" shield machine maintenance frequency. By increasing the integrity of the equipment and eliminating normal shutdown, ensuring the "Longxiang" The shield machine is always in a state of good excavation and effectively avoids the risk of "deep burial".

Long -distance tuning is another difficulty in the construction of Longquan's inverted siphon shield. The 90 -meter "Longxiang" opened a 5 -kilometer tunnel in the ground, just like the "blind man touching the image". The error of 1 mm during the excavation process would cause the tunnel line to deviate. Precise measurement is particularly important.

"I propose to measure myself, and then ask the company to re -test." "Not only must the company repeat the test, but also the three -party professional institutions must be reviewed again." At the shield measurement exchange meeting, the project technicians scrambled to suggest.

"Let's comprehensively carry out, and multiple testing methods are used. We must also increase the frequency of testing. In particular, we pay special attention to each station change measurement to ensure that it is everything." Gong Zhenyu made a hammer.

Since starting the construction, the project department has carried out more than 270 times in conventional measurement, organized 9 times in the well -down measurement measurement, and 12 times in the cave. At the same time, the third -party professional measurement agency was invited to calibrate the review. Go forward. During the receiving phase of the last kilometer, the project department hired professional surveying agencies for gyroscopy to measure the target to accurately position the shield machine. On June 21, when the "Longxiang" broke out, it fits strictly with the receiving well. Create innovation and courage to fight for first -class

On June 23, 2021, the Kunming Branch of the Central Yunnan Water Draving Project Construction Management Bureau sent a congratulatory letter to the project department to congratulate the project department "zero pollution" and "zero sedimentation" successfully through Panlongjiang and Panlongjiang Bridge. Behind the congratulations, all employees of the project department strictly control safety and quality risks and create innovative "ingenuity".

Due to the vertical intersection of the Longquan Rainbow Tunnel and Panlongjiang, the top of the tunnel is 9.3 meters from the bottom of the Panlongjiang bed and only 6.9 meters from the bottom of the Panlongjiang Bridge. Under the construction conditions, the "Longxiang" is prone to surge in construction under construction, resulting in the foundation of the Panlongjiang Bridge.

"You must pollute and settle down!" This is a consistent opinion reached when the project department compiles the feasibility crossing special construction plan. After the plan was approved, the project department immediately carried out detailed technical intercourse and safety training, set up the risk control command room and emergency rescue team through Panlongjiang, establish an instant communication platform in the cave, ground, and command room, and monitor the construction parameters of the shield in real time. Formulate risk control plans in advance. Two technicians hold measurement instruments and monitor Panglongjiang bridge bridge pier, bridge, bridge deck every 2 hours. At the same time, the project department uses large ground screen to automatically display the real -time scenario system in the tunnel, the ground settlement monitoring system, and the shield excavation parameter analysis system. Through remote monitoring, the construction status and personnel activities in the cave are observed at any time. Change and parameters change adjustment of the shield machine to digging the posture, effectively ensuring the safety and quality control in tunnel construction.

In addition, the project department carried out detailed geological replenishment work to improve the design defects.经过反复数据论证，大胆尝试，变被动换刀为主动换刀，将适应上软下硬地层的刀具更换成适应下一阶段软土地层的刀具，提高刀具的适应性；根据不同地质、水文、 Burning deep, ground buildings, etc. scientifically and reasonably choose excavation parameters and improve the soil improvement, which greatly improves the efficiency of excavation. During the construction, the project department and Central South University carried out the topic of "key technologies of ultra -deep buried long -distance long -distance long -distance long -distance long -distance long -distance long -distance long -distance long -distance long -distance long -distance long -distance long -distance long -distance long -distance long -distance long -distance long -distance long -distance long -distance water diversion tunnel shields", obtained 5 papers, 5 national patents, 3 provincial construction laws, and QC awards for industry associations Two equal results.

Source: China China Railway

Edit: Lulu

Review: Jia Qi

School pair: Qin Sufeng

Editor: Deng Zhuo

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