Chinese engineers extracted a record-breaking 38.1-meter-long concrete core sample from a dam in southwest China on Sunday.
The cylinder was drilled from the Yebatan Hydropower Station, a project located at the junction of Baiyu County in Sichuan Province and Konjo County in Xizang Autonomous Region, in the southwest part of China.
The Yebatan station is being built on the upper reaches of the Jinsha River, which forms the upper mainstream section of the Yangtze River. With a highest elevation of nearly 2,900 meters -- the dam will stand 217 meters tall and have an installed capacity of 2.24 million kilowatts, placing it among the country's largest hydropower projects.
Notably, the lifespan of a dam depends on how well its concrete was poured. The project's developer said that the massive core sample, roughly the height of a 12-story building, remained intact as it was extracted, indicating that the dam's concrete was laid to a high standard. The 245-millimeter-wide core was drilled vertically through 13 sections of the arch dam, cutting across 12 horizontal joints and 80 layers of poured concrete.
While setting a new national benchmark for core sampling in similar arch dam types, the extraction of the core sample also showcased the country's advanced concrete pouring and quality control capabilities in challenging high-altitude environments.
"We can see that the surface of this core sample is smooth and flat, with an even distribution of concrete aggregates. The cementing of materials is clear and complete, and especially, the bonding between the concrete layers is quite good. The record-breaking length of this core sample marks that China's arch dam concrete construction technology in high-altitude cold regions is now at the forefront of the world," said Xia Yong, chief engineer of Huadian Jinsha River Upstream Hydropower Development Co., Ltd.
Construction of the hydropower station's main structure began in September 2018, and its first generating units are set to be online by late 2025.
As a key part of China's west-to-east power transmission program, the station is expected to generate roughly 10.2 billion kilowatt-hours of electricity per year, once it is fully operational.
It will save almost 4 million tonnes of standard coal and cut carbon dioxide emissions by about 7.4 million tonnes annually, contributing to the country's strategy to curb greenhouse gas output, as it aims to peak emissions by 2030 and reach carbon neutrality by 2060.
China showcases high-altitude engineering prowess with 38-meter core sample extracted
