Rock Masses Classification And Gradation And Its Application On Lixianjiang Hydropower Project

With the development of China economy, there is an eager requirement for the power supply which results a rapid developing in hydropower industry. The concrete arc dam, as a recognized economic and safe dam pattern, has been widely suggested to the huge or super-huge hydropower project in China. An technical issue, different requirements for rock masses quality in the dam foundation to fit different dam pattern, arose in the dam design procedure due to the difference in project scale and engineering geological properties. Assessing the rock masses quality precisely as well as classification and gradation is significantly important in dam design, dam pattern optimization, stability assessment and foundation improvement.Rock masses classification and gradation for dam foundation is one of the important engineering geological issues in Lixianjiang hydropower project, Yunnan, China. The paper summarized all the latest developments in rock masses classification and rock mass gradation in the world, based on the project characteristics and the geological condition of regional geological pattern, topography, stratigraphy, tectonic pattern, weathering, hydrogeology, analyzed influence of various geological factors on rock masses quality, considered a laboratory testing results, a new rock masses gradation system has been proposed. Based on previous rock masses classification of Chinese Standard for Engineering Classification of Rock Masses (GB50287-94), RMR, Rock masses classification for hydropower project dam foundation, considering the following factors of rock hardness, rock structures, intactness of the rock, joint plane condition and XXX, weathering and groundwater, a new rock mass classification chart combining qualitive and quantitive factors has been proposed and a rock mass classification result has been figured out. Based on gradation result and rock mass classification theory and method, the mechanical indices of the rock masses have been estimated and simulated. Some mechanics indices for rock masses have been proposed. The rock masses quantities for dam foundation have been assessed and important geological indices which will influence the stability of the dam foundation and deformation have been given to assess the slide stability and deformation stability of the dam foundation.