What is RQD mining?
What is RQD mining?
Rock quality designation (RQD) is a standard technique in the mining industry for the qualitative and quantitative assessment of rock quality and degree of jointing, fracturing, and shearing in a rock mass.
What is the use of RQD?
RQD is used to evaluate quality of rocks such as degree and depth of weathering, zones of rock weakness and fracturing. This information is used for determining the depth of foundations, bearing capacity of rocks, settlement and sliding possibilities of foundations.
What is Blastability?
Blastability can be defined as the blasting characteristics of the rockmass subjected to a specified blast design, explosive characteristics and specified legislative constraints depending on the site specifics. In other words, blastability indicates how easy to blast a rockmass under a specified condition.
What do you mean by RQD how it is determined?
Determination of RQD. RQD was proposed by Deere (1964) as a measure of the quality of borehole core. The RQD is defined as the ratio (in percentage) of the total length of sound core pieces that is 0.1 m (4 inch) or longer to the length of the core run.
What are the benefits and limitations of RQD?
The empirical methods which are based on Rock Quality Designation provide a very convenient way for estimation of the deformation modulus and unconfined compressive strength of rock masses….Condition of the Rock as Per There Rock Quality Designation.
| Condition of the Rock | RQD in % |
|---|---|
| very good( fresh rocks) | 91 to 100% |
Who developed RQD?
RQD was developed in 1964 by D. U. Deere*. It is determined by measuring the core recovery percentage of core chunks that are greater than 100 mm in length.
What is RQD civil engineering?
Abstract:- The rock quality designation (RQD) is a commonly used index for the description of rock mass fractured state. The RQD was initially introduced for civil engineering applications, and it has been quickly adopted in mining, engineering geology as well as geotechnical engineering.
How do you calculate Blastability index?
Taking into account the parameters of the Blastability Index (Scott, 1996) (BI = 0.5 x (RMD+JPS+JPO+SGI+H) (Lilly, 1986), the Blastability Index (BI) is calculated for every possible combination of the above parameters, which refers to powdery/friable rock mass.
What is the value of RQD for sound rock?
Classification table
| RQD | Rock mass quality |
|---|---|
| <25% | Very poor |
| 25-50% | Poor |
| 51-75% | Fair |
| 76-90% | Good |
What is RQD and TCR?
Various criteria can be used for quantitative description of the fracture state of rock cores; these are the total core recovery (TCR), solid core recovery (SCR), fracture index and rock quality designation (RQD). The definitions of these terms are given in BS EN ISO 22475-1.
What is RMR in geology?
The rock mass rating (RMR) is a geomechanical classification system for rocks, developed by Z. T. Bieniawski between 1972 and 1973.
What is mining RMR?
