The subway is the inevitable result of the development of big cities. At the beginning of the development of transportation, it is equivalent to the value of airplanes, all in order to overcome the limitations of ground roads. Recently, the east extension section of Metro Line 5 and Metro Line 10 under construction have successfully achieved major project nodes, and both realized the launch of the first shield machine, marking the entry of the line into the construction phase of the interval tunnel. The former extends eastward from the existing Wenchong Station to the Huangpu Passenger Port Station, which will realize the rapid connection between the Huangpu Development Zone and the central city. The latter runs through the four central urban areas of Tianhe, Yuexiu, Liwan, and Haizhu, and is a veritable central urban rail transit “encrypted line”.

Up to now, the civil works of the east extension section of Line 5 have been completed 7%. Among the 6 stations, 4 are undergoing civil construction and 2 are undergoing pre-construction preparations. The civil works of Line 10 have been completed by 8%. Among the 14 stations, 11 are undergoing civil construction and 3 are undergoing pre-construction preparations.

East Extension realizes rapid connection between Huangpu Development Zone and central city

The east extension of Line 5 extends east from the existing Wenchong Station to the Huangpu Passenger Port Station, which will realize the rapid connection between the Huangpu Development Zone and the central city, and further optimize the role of the existing Line 5 as an important transportation line in the central city of Guangzhou , To promote the realization of the city’s eastward strategy.

The section has a total length of 9.8 kilometers, with 6 stations including Shuanggang, Miaotou Road, Xiayuan, Baoying Avenue, Guangzhou Development Zone and Huangpu Passenger Port Station, including 2 transfer stations and 1 Shuanggang parking lot. , The train adopts 6-section marshalling train consistent with Line 5.

The first shield machine "Craftsman No. 5-1" in this section is responsible for the construction of the right-line tunnel between Guangzhou Development Zone and Huangpu Passenger Port (hereinafter referred to as "Guangzhou-Huangzhou Interval"). The tunnel is 931 meters long and the main geology is silt. Quality silty fine sand, medium coarse sand, silty clay layer. The "Sister" shield machine "Craftsman No. 5-2", which was launched at the same time as the "Craftsman No. 5-1", was launched from the air shaft to the Miaotou section (hereinafter referred to as "Shuangmiao Section") and was responsible for Shuangmiao The excavation work of the 1071-meter-long tunnel on the right line of the section will face complex construction challenges such as bedrock protrusions, underpassing high-pressure gas, and Shougouling fracture.

It is reported that the first shield machine has started smoothly, but there are still many difficulties to be overcome in the construction of the east extension section of Metro Line 5. The surrounding environment of the line is complex, there are many risk sources along the line, the geological conditions are complex and changeable, the number of pipeline relocations, the amount of pipeline leveling and coordination, the variety of construction techniques, and the frequent process conversion all pose high challenges to construction management and control.

Central urban rail transit "densified line" Line 10 crosses the Pearl River

"Xiti"'s first shield machine is also Metro Line 10. After the completion of Line 10, it will be connected to the section from Tianhe Passenger Transport Station to Shipaiqiao of Line 3, and will run through the four central urban areas of Tianhe, Yuexiu, Liwan, and Haizhu. It is a veritable central urban rail transit "encrypted line".

The line is about 19.15 kilometers long, with Tianhe Road, Guangzhou Avenue Middle, Siyouxin Road, Shuqian Road, Donghu, Binjiang East Road, Zhongda South Gate, Wufeng, Dongxiaonan, Shixi, Daganwei The 14 stations, including Dongsha, Dongsha, Guanggang New Town and Xilang Station, are all underground stations, including 10 transfer stations. After the completion of Line 10, it will run through the section from Tianhe Passenger Transport Station to Shipaiqiao of Line 3; One depot in Gangxin City. The vehicle adopts a 6-carriage B-type vehicle with a maximum operating speed of 80 km/h.

The first shield machine "Yuejin No. 1" of Line 10, which has been carefully assembled and debugged, started from Dongsha Station and drove northward, and was responsible for the construction of the right-line tunnel between Dongsha and Daganwei. The tunnel is 1794.5 meters long. During the tunneling of the tunnel, the shield machine mainly traverses complex formations such as strongly weathered silty mudstone, strongly weathered argillaceous siltstone, moderately weathered silty mudstone, and moderately weathered argillaceous siltstone, and successively descends. The construction risks of the Yajisha Bridge, Yajisha Island and the Pearl River Channel are extremely high.

In order to ensure that the shield machine passes through the Pearl River smoothly and smoothly, for the high clay content of the strata in this section, the phenomenon of "mud cake" may occur in the center of the cutter head and the shield machine passes through the embankment due to changes in the soil over the tunnel. As a result of the sudden change of shield attitude and other problems, the subway builders “upgraded” the shield machine, adopted a large opening design in the cutter head center, and formulated solutions for muck improvement. In the screw machine, the anti-spray design is adopted, the auxiliary air pressure is used to reduce the catchment of the soil bin, increase the amount of foam to improve the slag, and use the pipe piece hoisting hole to inject the double liquid slurry circularly to plug.

In addition, "Yuejin No. 1" also reserves 8 route injection holes and 8 advance exploration holes in the front shield and the middle shield. These reserved holes can be injected with bentonite or thick grout or inert grout to reduce the thrust to ensure the stability of the soil layer during the tunneling process. The advanced exploration holes can also facilitate subway construction when encountering difficult strata or special conditions. Reinforce the ground in advance to ensure maximum construction safety.

Fast and comfortable, occupying less land resources, large passenger traffic, low energy consumption, low pollution, high safety performance, etc., this emerging mode of transportation has received more and more attention in the construction of large and medium-sized cities in my country, and has received more and more attention. Wide range of applications. With the increasing progress of the construction progress bar of Guangzhou Metro Line 5 and Line 10, it is believed that it will bring greater tolerance to Guangzhou.Editor/Luo Wentao