[Integrated] Longquanshan Tunnel Difficulties: One-meter-a-day workers wear antistatic clothes every day

Since the completion of the Longquanshan Tunnel on the Tianfu International Airport Expressway, it has been accumulating more than 300 meters so far.

The roar of machines continued and the construction vehicles kept going and stopping... Yesterday morning, at the construction site of the Longquanshan Tunnel on the Tianfu International Airport Expressway at Taiping Street, Tianfu New District, dozens of workers were nervously digging tunnels and pouring concrete. At present, there are more than 300 constructors working on the spot and the four tunnels are progressing simultaneously. Since the start of more than three months, as of now, more than 300 meters have been promoted.

It is understood that the Longquanshan Tunnel, one of the difficult points on the highway of Tianfu International Airport, is currently under intense pressure. The entire tunnel is expected to be completed in August 2019, and an opening capacity will be formed in November. The 13th Party Congress of the City proposed the implementation of the strategy of “going to the east”. The highway of the Tianfu International Airport where the Longquanshan Tunnel is located connected to the downtown area and Tianfu International Airport, providing important transportation support for the “Dongjin” strategy.

High gas

Workers wear anti-static clothes into the hole

“There are now 300 workers on the construction site who are working day and night. Workers are stationed on camps less than 500 meters from the tunnel site. They will do three shifts in 24 hours.” Deputy Commander of Expressway Command of China Railway Titian International Airport Chen Xiaobo told reporters that this arrangement is to enable the tunnel to be opened at an early date. The fastest tunnel No. 1 has been excavated at 170 meters and is expected to be completed in June 2019.

At the scene, the reporter saw that compared with other construction sites, the workers here were wearing stricter clothes. They not only wore helmets but also wear anti-static clothes. The reason behind this wearing requirement is precisely because the Longquanshan Tunnel is a high-gas tunnel. This is also the biggest difficulty in the entire construction process. “In order to cope with high gas, workers wear anti-static tooling kits made of pure cotton and all inflammable and explosive materials such as mobile phones and lighters are located outside the construction site,” said Chen Xiaobo. The reporter noticed that at the No. 1 hole and No. 3 opening where more than 100 meters have been excavated, the blower with a height of more than 20 meters is making headway. Chen Xiaobo told reporters that the purpose of doing so is to ensure continuous and continuous ventilation in the tunnel.

Easy to collapse

Push forward up to 1 meter per day

The difficulties in the construction of Longquanshan Tunnel are far more than high gas. Poor geological conditions have brought a lot of difficulties to the construction. “Almost all of them are silty mudstones. It is not rainy and the soil is hard. When it rains, it becomes mud and there is a chance of collapse.” Chen Xiaobo said at the same time, The cross section of the two 3-lane tunnels is 183 square meters, which is far beyond the section of 120 square meters of common tunnels. Under the premise of poor geological conditions, the construction of large sections is more difficult. In addition, because the Longquanshan Tunnel is designed with a parallel 4-hole layout, the net spacing between the tunnels in the inlet section is very small, only 15 to 25 meters. “Construction of tunnels at the same time will affect each other, especially in blasting operations. The stability of the intermediate rock wall is also poor and the construction safety risk is high,” said Chen Xiaobo.

In order to allow the tunnel to be opened as soon as possible and prevent any difficulty from delaying the construction period, the builders have developed many countermeasures. “The surrounding rock is easy to collapse and we dig little by little, digging only 60 cm at a time, and then we support it with a steel frame and push it forward almost every day for 1 meter.”

It is understood that the Longquanshan Tunnel is the first one-way, five-lane, double-hole tunnel in the province. It has a total of four tunnel holes, each measuring 2.3 to 2.4 kilometers long. Since the construction of the tunnel started in March, the construction process has been proceeding smoothly. The four tunnels of No. 1 tunnel have all started to excavate. Up to now, a total of more than 300 meters has been promoted. It is expected that the tunnel will be established in September 2019, and the opening capacity will be formed in November, and the other high-speed tenders will also be in an orderly manner. In 2019, the Tianfu International Airport will be completed and put into use.

“At present, we are accelerating the construction of the remaining projects in the Sanhe South section, and strive to be completed and opened to traffic before September 30th. The east section of the Sanjuan is also in an orderly manner.” The relevant person in charge of the Municipal Communications Commission said. Reporter Tian Chengchen Yuan Hongwen/Figure