China News Service, Urumqi, November 10 (Gou Jipeng and Yao Long) Just after the beginning of winter, the temperature at the construction site of the Tianshan Shengli Tunnel in Xinjiang dropped even lower.
At the construction site, the tank body of the concrete transportation vehicle is wrapped with cotton felt. The shaft hoisting machine room, air compressor room, car stabilizing room, and derrick are all sealed with cotton felt and 10cm thick rock wool insulation board. On-site vehicle equipment is replaced. A thick "winter clothes".
The Tianshan Shengli Tunnel site is located in a high-cold and high-altitude area. The normal effective construction time per year is only 5 months from the beginning of May to the end of September. According to the requirements of the overall project schedule, the effective construction time per year is at least 10 months.
“For this reason, the project adopted thermal insulation measures for the main tunnel, mixing station, belt conveyor, and shaft to ensure that the temperature of the construction area is above 5°C, and pays real-time attention to the construction temperature in the tunnel and the concrete entry temperature, and takes a variety of effective measures. Ensuring winter construction.” Gao Yanyao, captain of the team directly under the main tunnel at the exit of the Tianshan Shengli Tunnel, said recently.
He said: “During transportation, wrap the concrete tank body with 5cm cotton felt for insulation, and preheat the concrete tank body through hot air pipes. The concrete conveying pipe is wrapped with cotton canvas, and the joints are wrapped with waterproof electric blankets. The temperature loss of the concrete during the conveying process should ensure that the moulding temperature is not lower than 5°C."
In addition, during winter construction, it is very important to control the temperature in the tunnel.
"We set up thermometers in the main cave at an interval of 50m, and designated a dedicated person to perform temperature detection regularly. We found that the temperature in the cave was below 5°C and immediately took measures. We also arranged for 6 people to work in shifts around the clock to ensure the temperature in the cave, especially in the initial support. After the sprayed concrete construction is completed, ensure that the temperature of the concrete construction surface reaches 10°C or more, and promote the concrete strength to rise as soon as possible to ensure the effectiveness of the initial support, ensure the stability of the excavation surface, and ensure the safety of the construction." Gao Yanyao said, the fan is still outside the tunnel Build a prefab house for heat preservation to ensure that the fresh air sent into the tunnel is above 0°C to ensure the temperature inside the tunnel.
At the same time, heating is also installed in each room in the living area of the construction site.
Sun Chao, a group of workers excavating at the exit of the Tianshan Shengli Tunnel, told reporters: “The room is very warm. Boilers are used for central heating in winter, and 10cm rock wool insulation boards and insulation doors are added to the temporary buildings to ensure heating in the living area in winter.”
The Tianshan Shengli Tunnel is a "throat" project that runs through the Tianshan Expressway-Wuwei Expressway in Xinjiang.
The design of the tunnel is about 22 kilometers in length. It is an extra-long high-cold and high-altitude highway tunnel. After completion, it will become the world's longest highway tunnel.
At present, the left tunnel at the entrance of the tunnel has been excavated and supported more than 1,300 meters, the right tunnel has completed more than 1,200 meters, and the excavation of the left and right double main tunnels at the exit of the tunnel has exceeded 2,100 meters.
(over)