Geostatistical modeling of Rock Quality Designation (RQD) and geotechnical zoning accounting for directional dependence and scale effect

2021 ◽  
Vol 293 ◽  
pp. 106338
Author(s):  
L. Katherine Sánchez ◽  
Xavier Emery ◽  
Serge A. Séguret
Keyword(s):  
Scale Effect ◽  
Geostatistical Modeling ◽  
Rock Quality Designation ◽  
Directional Dependence ◽  
Rock Quality

scholarly journals Characteristics Analysis of Generalized Rock Quality Designation (RQD) Based on Degree of Joint Development

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Lin Jun ◽  
Sha Peng ◽  
Gao Shuyu ◽  
Ni Jiji
Keyword(s):  
Rock Mass ◽  
Scale Effect ◽  
Great Influence ◽  
Optimal Threshold ◽  
Open Pit ◽  
Rock Quality Designation ◽  
Network Modelling ◽  
Fracture Spacing ◽  
Joint Development ◽  
Rock Quality

Rock quality designation (RQD) is widely adopted as a fundamental tool in characterizing rock masses since it was devised in 1964. Since the conventional RQD calculation is limited due to its dependence on the selected threshold, previous research introduced generalized RQD to adequately reflect the anisotropy and scale effect of RQD. However, the influence of the joint development inside rock mass on generalized RQD remains unclear. The objective of this work is to investigate characteristics of the generalized RQD in view of different development degrees of discontinuities in rock mass, including spacing (density) and trace length. Three-dimensional fracture network modelling is employed to simulate the actual rock mass of open-pit iron mine in China. Virtual scanlines are set to obtain RQD values in different directions. The results primarily show that the generalized RQD should be introduced to calculate the RQD with different thresholds to fully reflect the anisotropy of rock mass. The optimal threshold can be obtained based on an anisotropic coefficient, which is defined by (RQDmax-RQDmin). It is also indicated that the fracture spacing has a great influence on both the anisotropy of RQD and the selection of the optimal threshold. The optimal threshold of the generalized RQD increases with the increase in the fracture spacing. In addition, the scale effect of RQD in different models is discussed by changing the length of the scanlines. The longer the scanlines we set, the more stable RQD value can be obtained in the model. It is recommended to fit much longer scanline to get realistic RQD in heavily fractured rock mass.

A Contribution to Relationship Between Volumetric Joint Count (Jv) and Rock Quality Designation (RQD) in Three-Dimensional (3-D) Space

2019 ◽  
Vol 53 (3) ◽  
pp. 1485-1494 ◽  
Author(s):  
Jun Zheng ◽  
Xiaohong Wang ◽  
Qing Lü ◽  
Jianfeng Liu ◽  
Jichao Guo ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Rock Quality Designation ◽  
Rock Quality

scholarly journals Engineering geological zoning of the Scorillo Dam site, Romania

2000 ◽  
Vol 22 ◽  
Author(s):  
Cristian Marunteanu ◽  
Ion Durdun
Keyword(s):  
Rock Mass ◽  
Modulus Of Elasticity ◽  
Grout Curtain ◽  
Rock Quality Designation ◽  
Rock Quality ◽  
Rock Mass Quality ◽  
Engineering Geological Zoning ◽  
Dam Site

A model of engineering geological classification and zoning of the Scorillo Dam site in Romania is proposed to optimise the design of the dam and of the grout curtain. The rock mass was classified into four categories: from 1 (good) to 4 (very poor), according to the rock mass quality (RMQ) at the dam site. Parameters available and used to determine the RMQ were lithology, degree of weathering and fragmentation, rock quality designation (RQD), and modulus of elasticity (E). Based on the study, a new design of the dam, its slopes, and the grout curtain was carried out.

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