Tunnels are not merely transportation facilities; they are the crystallization of human wisdom, a perfect fusion of technology and natural forces. The history of tunnels can be traced back to ancient times, but real breakthroughs occurred in modern times. At the end of the 19th century, with the advancement of the Industrial Revolution, tunnel engineering began to be widely applied. The history of tunnel construction in China also unfolds as a story of continuous innovation and progress.

　　The 1950s and 1960s: Difficult Exploration with the Drill-and-Blast Method

　　In the 1950s and 1960s, China mainly used the drill-and-blast method, relying on manual labor and small machinery for rock drilling and loading in tunnel construction. This period was marked by extremely arduous conditions and low construction efficiency. A typical example is the Liangfengya Tunnel on the Chuanqian Railway, which is 4270 meters long. The construction of this project required immense manual labor and effort.

　　The 1970s: Formation of Independent Construction Techniques

　　Building on the experiences of the 1950s and 1960s, the 1970s saw the development of a complete set of independent tunnel construction techniques in China, ushering in an era of proactive tunnel construction. The Yimaling Tunnel on the Jingyuan Railway, spanning 7032 meters, is a representative work of this period. This era marked the maturity of China's tunnel construction technology and an enhancement in its ability for independent innovation.

　　The 1980s: Introduction of Hydraulic Drilling Technology

　　In the early 1980s, China imported a series of advanced equipment such as hydraulic drilling jumbos from Nordic countries, significantly improving the level of mechanized tunnel construction. The Dayao Mountain Double-track Tunnel on the Hengguang Railway, with a length of 14295 meters, exemplifies the improved mechanization of this period.

　　The 1990s: Achieving International Standards

　　In the 1990s, China made remarkable progress in tunnel construction technology, covering in 20 years what took developed countries 50 to 100 years, reaching international standards. The Qinling Tunnel on the Xikang Railway, stretching 18460 meters, is an important representative work of this stage, signifying China's integration with global tunnel construction technologies.

　　2008: First Crossing of the Yangtze River

　　In 2008, the Wuhan Yangtze River Highway Tunnel was officially opened, marking the construction of China's first tunnel crossing the Yangtze River and opening a new chapter in China's tunnel construction.

　　2017: Crossing the Sea

　　In 2017, the world's longest underwater immersed tube tunnel, the Hong Kong-Zhuhai-Macao Bridge immersed tube tunnel, was successfully completed, symbolizing China's world-leading capability in underwater tunnel construction. This project demonstrated China's outstanding technology in underwater tunnel construction.

　　2018: Conquering the Tianshan Mountains

　　In 2018, the world's longest highway tunnel, the Tianshan Shengli Tunnel from Urumqi to Yining, began construction, extending 22 kilometers. This milestone marked China's ability to overcome challenges in high-altitude and cold environments, showcasing determination and capability in constructing tunnels under complex geological conditions.

　　2020: Commencement of the Pearl River Estuary Tunnel on the Shenjiang Railway

　　In 2020, construction began on the Pearl River Estuary Tunnel on the Shenjiang Railway, which features the greatest depth and highest water pressure among China's underwater tunnels. This project represents a new level of China's "underground" technology, highlighting further breakthroughs in underwater tunnel construction.

　　From the initial drill-and-blast method to advanced modern excavation techniques, China's tunnel construction has undergone multiple stages of technical accumulation, independent innovation, and international integration. Each milestone project not only represents advancements in China's tunnel construction technology but also attests to the wisdom and effort of Chinese engineers. Through the continuous introduction and development of new technologies, China's tunnel construction has now reached the forefront of the world, demonstrating strong engineering prowess and technical expertise.