China's longest undersea shield tunnel of intercity railway has successfully crossed the artificial island of Shenzhen-Zhong passageway

On August 29, the longest undersea shield tunnel of intercity railway in China, the left line shield tunnel "Shenwan II" of Suiguan-Shenzhen Railway front section project, which was built by China Railway 14th Engineering Bureau, successfully crossed the artificial island of Shenzhen-China tunnel, which marked that the double-line shield structure of the project had completed undercrossing the major risk source.

The Suiguan Deep tunnel front project is a double-hole single-line shield tunnel, constructed by two large-diameter mud-water balanced shield tunneling machines. It is the only tunnel with the longest single-head tunneling distance and undergoes the sea. In the process of shield tunneling through the deep-middle channel in the West Bay of Shenzhen sea, it is necessary to drill in the upper soft and lower hard stratum and the granite hard rock stratum, which is a major risk and easy to cause stratum subsidence and mechanical failure.

Shield to ensure smooth completion of under wear, pressure-pad-force channels for hard rock strata excavation tool is easy to wear and tear problems, in order to ensure the continuous excavating shield efficiency, under the shield of the left line wear before artificial island, full screen tunnel under wear period of geology, combined with the changing proportion of hard and soft stratum, the use of advanced grouting process on soft hard formation under the soil reinforcement, improve safety precontrol measures, strengthen the regulation of process, At the same time, make adequate emergency preparations. The project summarizes the previous tunneling experience, organizes and establishes the tool database, optimizes the tool of this project, reduces the abnormal damage of the tool, greatly improves the service life of the tool, and ensures the efficient tunneling of shield.

During the tunneling process, the whole project made concerted efforts to strictly control the tunneling parameters, reasonably adjust the shield posture, pay close attention to the grouting pressure, strictly implement the ground monitoring, ensure the real-time ground monitoring, quickly adjust the tunneling parameters, and strictly control the impact on the island body and ground buildings. It took 65 days to successfully complete the 205-meter penetration mission.

As an important link of the Guangdong-Dongzhou-Shenzhen intercity Railway, the front section of the Guangdong-Dongzhou-Shenzhen intercity Railway is scheduled to be completed and put into operation by the end of 2024. By then, the intercity high-speed trains will directly reach Qianhai and Bao 'an Center, which is of great significance for improving the intercity network of the Guangdong-Hong Kong-Macao Greater Bay Area and realizing regional economic integration.