On July 1, the Hunan Jiaohua Reservoir Hub Project undertaken by Sinohydro Bureau 8 Co., Ltd. successfully extracted a three-graded roller-compacted concrete core sample measuring 28.55 meters in length and 273 millimeters in diameter, once again setting a new world record for roller-compacted concrete core samples! This breakthrough achievement not only set a new world coring record for roller-compacted concrete dams, but also demonstrated the top level of China's water conservancy engineering construction with solid strength.

To ensure "zero" errors throughout the coring process, the project department immediately launched a special task plan, formed a dedicated team, allocated equipment, strictly followed design specifications, implemented safety and quality control measures, and continuously optimized the construction process. The project team carried out refined monitoring and control throughout the entire process, including equipment positioning, drilling rig calibration, drilling parameter control, and core sample lifting. The core sample ultimately extracted had a smooth and dense surface, uniform aggregate distribution, a compact structure, and good interlayer bonding, objectively reflecting the roller-compacted concrete construction quality of the Jiaohua Reservoir Project dam and providing an important basis for the acceptance of the Jiaohua Reservoir Project.

The dam of the Jiaohua Reservoir Hub Project is a roller-compacted concrete gravity dam, with a crest elevation of 181.5 meters, a maximum dam height of 69.5 meters, and a crest length of 420 meters. During the construction of the main dam structure, the project team innovatively applied the high-lift continuous formwork raising process and the full-section full-bay inclined-layer rolling technology. The former achieved seamless connection between construction layers through a modular formwork system, greatly improving dam pouring efficiency; the latter ensured uniform and compliant concrete density through an innovative rolling path design. The successful practice of these cutting-edge processes not only laid a solid foundation for project quality, but also effectively shortened the construction period through standardized construction procedures, providing a replicable and promotable "Chinese solution" for similar water conservancy projects.

After completion, this reservoir project, which shoulders an important livelihood mission, will have an average annual water supply capacity of 86.2 million cubic meters. It will mainly serve urban water supply and flood control, while also accommodating irrigation and ecological water replenishment for the downstream area, providing solid guarantees for domestic and industrial water use for 400,000 residents downstream of the Liuyang River.