星空传媒91传媒制片厂|明星换脸五级片|麻豆传媒映画女演员王茜|麻豆在传媒在线|九九国产|91制片厂在线观看一二区|夜夜草视频|四虎影院在线播放|国产精品亚洲国际在线看|大象传媒国产第一页,麻豆映画传媒有免费的吗,91制片厂安卓,亚洲成年人精选,91你懂得国产,爱豆视传媒短视频免费,免费一级片

China has reached an engineering milestone with its domestically developed shield machine successfully completing the excavation of an underwater high-speed rail tunnel at a depth of 106 meters below the seabed in the Pearl River Estuary, according to China Railway's 14th Bureau Group, which is overseeing the project.

On Monday, the Shenjiang 1 shield machine completed its 3,590-meter excavation mission for the Pearl River Estuary Tunnel.

The tunnel, on a crucial 13.69-kilometer segment of the Shenzhen-Jiangmen Railway in Guangdong province, was built using a combination of mining and shield tunneling techniques to navigate complex geological conditions.

The shield machine, with a cutting diameter of 13.42 meters, progressed 3.59 kilometers from Dongguan to Guangzhou's Nansha district. It traversed 13 different geological strata and five complex geological formations, facing unprecedented conditions.

The tunnel's lowest point, 106 meters beneath the estuary, subjected the Shenjiang 1 to extreme water and soil pressures. The machine can withstand water and soil pressures of up to 10.6 bar, which is equivalent to a pressure of 10.6 kilograms on an area the size of a fingernail.

"This level of pressure and depth is unprecedented in China, with no existing engineering experience or design standards to guide the project," said Li Bing, an engineer from the China Railway 14th Bureau Group.

Chen Xingfei, another senior engineer with the group, said the Shenjiang 1 began its journey in December 2021, completing the excavation in 969 days. The project included a particularly challenging 490-meter fault zone with varying rock layers and high water pressures. The widest fault, measuring 32.5 meters across, added to the complexity and risk of the operation.

The Shenjiang 1 was designed for the task, incorporating advanced technologies such as high-precision circulation systems, automated pressure sealing, and sophisticated ventilation and cooling systems.

Once completed, the Shenzhen-Jiangmen Railway will stretch 116 km and operate at speeds of up to 250 kilometers per hour, linking the Guangdong cities of Shenzhen, Guangzhou, Dongguan, Zhongshan and Jiangmen. The line will significantly enhance regional connectivity, allowing travel between Shenzhen's Qianhai Free Trade Zone and Guangzhou's Nansha Free Trade Zone in just 30 minutes and boosting economic development in the Guangdong-Hong Kong-Macao Greater Bay Area.