摘要
Rock-quality designation(RQD) plays a significant role in rock mass analysis and is an important parameter in geotechnical and geological engineering.However,the RQD variation with scanline length has not yet been comprehensively considered in RQD.In this study,three-dimensional fracture network modeling was used to simulate actual rock mass,and numerous scanlines were set in the fracture network for investigation on RQD variation.Models and equations(i.e.,models A-A,N-N,and A-A-S,as well as the Priest-Hudson and Sen-Kazi equations) were summarized for the study.A corrected equation was proposed to eliminate the errors from using the Priest-Hudson and Sen-Kazi equations.In addition,inhomogeneous and anisotropic features were investigated,and the optimal thresholds for RQD calculation were determined,which varied with the study orientation and rock mass feature.When the inhomogeneity was studied in the x direction,the optimal threshold was found to be 4 m.When anisotropy was studied,the optimal threshold was found to be 3 m.
Rock-quality designation （RQD） plays a significant role in rock mass analysis and is an important parameter in geotechnical and geological engineering. However, the RQD variation with scanline length has not yet been comprehensively considered in RQD. In this study, three-dimensional fracture network modeling was used to simulate actual rock mass, and numerous scan- lines were set in the fracture network for investigation on RQD variation. Models and equations （i.e., models A-A, N-N, and A-A-S, as well as the Priest-Hudson and Sen-Kazi equations） were summarized for the study. A corrected equation was pro- posed to eliminate the errors from using the Priest-Hudson and Sen-Kazi equations. In addition, inhomogeneous and aniso- tropic features were investigated, and the optimal thresholds for RQD calculation were determined, which varied with the study orientation and rock mass feature. When the inhomogeneity was studied in the x direction, the optimal threshold was found to be 4 m. When anisotropy was studied, the optimal threshold was found to be 3 m.
基金
supported by the National Natural Science Foundations of China (Grant Nos. 40872170,40902077 and 41072196)
the Doctoral Program Foundation of Higher Education of China (Grant No. 20090061110054)
2010 non-profit scientific special research funds of Ministry of Water Resources (Grant No. 201001008)
Jilin University's 985 project (Grant No. 450070021107)
the Graduate Innovation Fund of Jilin University (Grant No. 20121073)
