The Gongyu Expressway stands as a monumental achievement, marking the inception of a groundbreaking era in highway construction within the permafrost-laden expanse of the Qinghai-Tibet Plateau.

Revered as the pioneering "three high" highway, it boldly surmounts formidable challenges of altitude, extreme cold, and demands for high-speed travel.

The whole route crosses the permafrost area, including 227 kilometers through the permafrost area, accounting for 36% of the total length of the route. Bridges and tunnels (single width) are 39.2 kilometers, accounting for 11% of the total length of the route. The Ela Mountain Tunnel and Jianglu Ling Tunnel are the first road tunnels designed and built in China's permafrost zone.

Navigating the challenges posed by constructing roadbeds, tunnels, and bridges in the multi-year permafrost zones inevitably provokes permafrost melting—a dilemma devoid of any precedent either within the nation or globally. This quandary represents a pivotal bottleneck in the realm of high-speed construction, standing as one of the paramount technical conundrums worldwide.

Along the highway, there is a large number of extremely unstable high-temperature permafrost, which is unique in the world, and the engineering geology and hydrogeology conditions are complicated. The entire route has a permafrost section that accumulated 227.7 km, accounting for 35.8% of the total length of the route.

The intricate nature of multi-year permafrost, coupled with high temperatures and significant ice content, manifests in sections characterized by poor thermal stability and other challenging attributes. Consequently, the construction necessitates road structures on a scale three to five times larger than the typical standards for highways and railroad infrastructure. This discrepancy underscores the magnitude of theoretical and technical challenges encountered in highway construction globally.

Chinese researchers rose to the challenge and actively invested in technical research, fully researching the Qinghai-Tibet highway improvement project's effect on the multi-year permafrost disposal test section, digesting and absorbing years of research results, and tailoring new technology and methods for the Gongyu Expressway's multi-year permafrost highway construction.

Multi-year permafrost refers to the soil in natural conditions where the frozen state lasts for three years or more, mainly distributed in high latitude or high altitude cold areas.

Although China has conducted research and observation on permafrost highways for over 50 years, the existing results are mainly for secondary and below-grade highways and the Qinghai-Tibet Railway, with no direct experience in applying them to highways.

In the multi-year permafrost area for roadbed, tunnel, bridge, and culvert construction, permafrost melting is inevitable, and there is no technical precedent to solve this problem in the country or even the world, making it a technical problem that must be resolved for the Gongyu Expressway's construction.

Therefore, technical personnel must prioritize addressing the "wide," "thick," and "black" challenges. The term "wide" pertains to the expansive width of the highway roadbed, stemming from the extensive polyheat effect. "Thick" denotes the substantial thickness of the highway pavement structure, attributed to the profound heat storage effect within the load-bearing pavement layers. Lastly, "black" signifies the potent heat absorption effect induced by the dark asphalt pavement.

Three generations of Chinese scientific researchers have adhered to the plateau for more than 40 years. They are a group of technical personnel who have shown persistence and perseverance, providing a solid technical guarantee for the construction of the Gongyu Expressway without leaving any traces.

The core components of the comprehensive ecological protection system for high-altitude alpine road construction encompass "road base clear surface turf transplanting technology," "high-altitude alpine area grass planting technology," and "road base high side slope ecological protection technology."

Leveraging the abundant resources of the Tibetan plateau, particularly turf, this system pioneers innovative approaches. Through the adoption of turf transplantation for slope protection in lieu of conventional methods such as window hole-type and rhombic skeleton protection, over 10 million square meters have been successfully completed, resulting in substantial cost savings exceeding 700 million yuan in construction investment.

With each milestone reached, the project etches its indelible mark in the annals of engineering prowess and human ingenuity. This expressway not only connects distant regions but symbolizes a testament to human perseverance amidst nature's harshest terrains.