How do you calculate the RMR of a rock?

The groundwater rating accounts for 15% of total ratings. The final RMR value of the rock is calculated as follows:(1) R M R = R 1 + R 2 + R 3 + R 4 + R 5 + R 6 where R1, R2, …, R6 are the ratings corresponding to six rock parameters as depicted in Table 2.

What is RMR in Rock Mechanics?

The rock mass rating (RMR) is a geomechanical classification system for rocks, developed by Z. T. Bieniawski between 1972 and 1973. Since then it has undergone multiple modifications out of which, RMR89 is commonly used.

How do you calculate JV in Rqd?

Jv = 1/S1 + 1/S2 + 1/S3 + …1/Sn Eq. (14) where S1, S2 and S3 are the average spacings for the joint sets.

What is RMR and SMR?

RMR values are then correlated into Slope Mass Rating (SMR) which is a system of classification of a rock slope. The study showed that the Rajamandala Limestone Mine area has RMR values of 66-71 and included in the class II or Good Rock and SMR ranged between 61° – 72° and belong to Good Slope class.

What is rock mass quality?

rock-mass quality (RMQ) A classification of rock for engineering purposes, based on the number of major joints or other discontinuities (planes of weakness) in it, their orientation, and their spacing.

What is Rqd soil investigation?

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.

How do you calculate volumetric joint count?

In the cases when mostly random or irregular joints occur the (Jv) can be found by counting all the observed joint within a known area. By assuming that the jointing has a uniform distribution, the (Jv) can be found by calculating the number of joints per unit area and multiplying this with a factor K.

What is SMR geology?

Slope mass rating (SMR) is a rock mass classification scheme developed by Manuel Romana to describe the strength of an individual rock outcrop or slope.

How do you calculate slope with mass rating?

6 Slope mass rating(SMR) : SMR = RMR(b) – (F1 . F2 . F3) + F4 • The SMR is calculated by subtracting factorial adjustment factors of the joint-slope relationship (F1. F2.

What is the RMR value for good roof condition?

RMR is determined as an algebraic sum of ratings for all of the parameters. On the basis of RMR values for a given engineering structure, the rock mass is sorted into five classes: very good (RMR 100–81), good (80–61), fair (60–41), poor (40–21), and very poor (<20).

What is Q value of rock?

Classification of the rock mass The rock mass quality (Q) is a very sensitive index and its value varies from 0.001 to 1000. Use of the Q-system is specifically recommended for tunnels and caverns with an arched roof.