The shield tunnel of guangzhou metro line 18 started smoothly

July 31, guangzhou metro line 18 and 22 ushered in a major critical node! With the shield tunneling of "tiebing 40" with a diameter of 8.8 meters breaking through the wall, the right line between west pazhou station and xiancun station successfully realized the initiation of shield tunneling.

With a length of 3 km, the tunnel is the first in China to cross the pearl river with a long distance (1600 m), small radius (600 m) and s-bend (two turns).

With a total investment of 76 billion yuan, guangzhou metro lines 18 and 22 are designed to travel 160 kilometers per hour. According to the plan, guangzhou metro lines 18 and 22 are responsible for connecting wanqingsha, guangzhou south railway station, guangzhou east railway station and baiertan, and extending to pazhou, guangzhou railway station and baiyun airport.

After completion, it only takes 30 minutes to take the subway from nansha national pilot free trade zone to guangzhou east railway station. It has exerted a profound influence on China railway construction by actively responding to the national initiative of "One Belt And One Road", promoting the development of guangdong-hong kong-macao greater bay area, and realizing the comprehensive transportation and public transportation development strategy in the pearl river delta region of China.

Facing many construction difficulties

Pomegranate duty respectively from the south to the north station, pa, pazhou, west station, pa xian interval (middle wind Wells), engineering geological and hydrological conditions, the natural environment is complex, line through guangzhou zhuhai, tianhe district, the flow field is narrow, change and move, through building is various, S bend across the pearl river, through the formation of argillaceous siltstone conglomerate, through the whole section red satellite village populated houses 150 danger coefficient is larger, pomegranate duty station north and south ends of underground construction with four sections.

The DL520 shield tunneling machine started this time is responsible for the tunneling task of the right line between pazhou west station and xian village station. The section starts from pazhou west station in the south, travels to the northwest, cuts through the beer museum, and then turns across the pearl river to xian village road in an s-bend form. After traveling north along xian village road for about 800m, it reaches xian village station with a total length of 3007m. The tunnel passes through the main stratum of argillaceous siltstone and conglomerate stratum, and passes through the completely weathered argillaceous siltstone stratum in some sections.

This section needs to run through the pearl river, pile foundations of existing buildings, wharves, existing lines, pedestrian passageways and other structures. The surrounding environment is complex and the construction risk is large.

The pearl river beer museum

The top of the tunnel is 0.67m away from the bottom of the pile foundation of the building. The overlying soil is mainly plain fill, silt, silty sand, fine sand, coarse sand, silty clay, and strongly weathered argillaceous siltstone. The undercrossing of the shield can easily lead to settlement and cracking of the building.

The undercrossing line is located in a strong and moderately weathered argillaceous siltstone

The nearest distance between the tunnel roof and the ground wall of modiesha tunnel is 1.16m. During the crossing, the settlement of existing tram lines and modiesha tunnel may be caused, posing a danger to the operating line.

Run down  lines 5

In the process of crossing, the settlement of line 5 is easy to cause, which poses a danger to the operation line. Through the no. 16 tunnel of pearl river new town and through the pile foundation group of channel 16, 40 piles need to be ground, which is easy to affect the channel.

To ensure the smooth starting, the shield project department continuously strengthen the allocation of resources, strengthen the construction control, overcome the space narrow, crossover operation, equipment failure and other difficulties, 29 days to complete the shield unit installed, debugging, organized six special construction plan, commenting on the expert's demonstration, on July 31, the smooth implementation of shield starting, for guangzhou metro line 18 tunnel all nodes target laid a solid foundation.