In the Dadu River Basin of Sichuan Province, China, the Shuangjiangkou Hydropower Station—one of the national 14th Five-Year Plan priority energy projects—is under steady construction. On-site, a blue dragon winds through the mountains, which is an automatic mixing and conveying system custom-designed by Fangda Group Northern Heavy Industries (hereinafter referred to as “NHI”) for this project. Serving as the material supply system for the anti-seepage process of the hydropower station’s earth-core rockfill dam, this system continuously transports earth and rock materials to the dam construction site.

The Shuangjiangkou Hydropower Station is a pivotal project in the cascade development of the Dadu River Basin, shouldering a critical role in China’s energy strategic layout. Its earth-core rockfill dam stands at 315 meters tall, with a total filling volume exceeding 46 million cubic meters. To visualize this scale: if the earth and rock were molded into a 1-meter-wide and 1-meter-high wall, it would stretch long enough to encircle the equator once.

The sheer scale of this project posed extreme demands on material transportation and handling. The project site is situated in a mountainous area with complex terrain and steep slopes, featuring a maximum gradient of up to 60 degrees. Under such challenging conditions, vehicle transportation proves not only inefficient but also energy-intensive, while generating severe dust pollution. These challenges placed enormous pressure on the local ecosystem and transportation infrastructure.

Facing challenges, the employees of NHI demonstrated their determination, drawing on their profound technical expertise and innovative spirit to undertake the design and manufacturing of the anti-seepage soil mixing system. Their efforts provided pivotal equipment and technical support for the construction of the Shuangjiangkou Hydropower Station.

The automated mixing, transportation, stacking-reclaiming, and digital control system developed by NHI represents a complex integration of cutting-edge technologies, involving over ten types of advanced equipment. Taking the gravel-soil mixture feeding system as an example, its conveyance network spans 9 kilometers in total length, comprising planar curved belt conveyors, tubular belt conveyors, steep-angle downward belt conveyors, and steep-angle sandwich belt conveyors. These conveyors each have unique technical parameters, demonstrating the technological innovation capability of NHI. The planar curved belt conveyor achieves a minimum turning radius of 600 meters in confined spaces, while the tubular belt conveyor boasts a minimum turning radius of 400 meters. Both conveyors enable agile navigation through rugged mountainous terrain and valleys. Notably, the sandwich belt conveyor accommodates a maximum downward inclination of -41.457° and an upward inclination of 60°, whereas the steep-angle downward belt conveyor handles a maximum downward angle of -24° and a vertical drop of -231 meters. Operating under such extreme gradients and elevation differentials imposes stringent demands on equipment stability and safety. However, NHI’s equipment rises to these challenges through advanced engineering design and precision manufacturing, ensuring efficient and secure material transportation.

This automated mixing and conveyance system integrates cutting-edge communication, configuration, sensor, logistics, and Internet technologies, establishing a comprehensive data acquisition and control interface platform for construction processes. Through this platform, it enables centralized monitoring, real-time data analysis, and intelligent early warning across the entire production workflow. Engineered for reliable operation under all-weather conditions, the system significantly enhances operational efficiency while minimizing reliance on manual labor at construction sites. By reducing labor costs and human-induced errors, it further elevates both construction quality and safety standards.

Furthermore, the technological advantages of NHI are also reflected in the intelligence, digitization, and informatization of equipment. These systems enable automated adjustment of soil-gravel weight ratios, replacing manual blending methods like bulldozer operations with a far more scientific and precise approach. This ensures consistent quality in dam filling materials. Additionally, the equipment incorporates automatic moisture content regulation, maintaining optimal mixing humidity for filled earth-rock materials. Such advancements enhance the dam’s structural integrity, laying a robust foundation for its long-term stable operation.

Over an elevation drop of 800 meters from 3,000m to 2,200m, NHI has engineered an innovative solution by integrating power generators into its belt conveyor systems. This setup enables three belt conveyors to generate 1,700 kW of electricity per hour. With 13-hour daily operation, the system produces nearly 8 million kWh annually—effectively transforming the 9-kilometer conveyance corridor into a miniature power plant. The recycling of this energy meets part of the electricity demand for construction, lessens reliance on external energy sources, and puts the green construction concept into practice.