Similar International Standards
Bieniawski 1989Z.T. Bieniawski (Publication/De Facto Standard), International
HighCurrent
Engineering Rock Mass Classifications: A Complete Manual for Engineers and Geologists
Defines the RMR89 system, an updated version of the RMR system upon which IS 10042 is based.
ASTM D5878-19ASTM International, USA
HighCurrent
Standard Guide for Using Rock-Mass Classification Systems for Engineering Purposes
Provides guidance on the application of major rock mass classification systems, including the RMR system.
Barton et al. 1974Norwegian Geotechnical Institute (NGI), Norway
MediumCurrent
Engineering classification of rock masses for the design of tunnel support (Q-System)
Presents the Q-system, an alternative quantitative method for classifying rock masses, primarily for tunnelling.
Hoek & Brown 1997E. Hoek & E.T. Brown (Publication/De Facto Standard), International
MediumCurrent
Practical estimates of rock mass strength (Geological Strength Index - GSI)
Introduces the GSI, a system for characterizing rock masses to estimate their mechanical properties, especially for weaker rock.
Key Differences
≠IS 10042:1981 is based on an early version of the Rock Mass Rating (RMR) system (circa 1976), while the current international de facto standard is the updated RMR89 (Bieniawski, 1989), which contains revised rating values for several key parameters.
≠The rating for discontinuity spacing in IS 10042 is significantly higher than in RMR89. For example, a spacing of >2m gets a rating of 30 in the IS code, whereas it only receives a rating of 20 in the RMR89 system.
≠Groundwater condition ratings differ. In IS 10042, the range is 0-10 (Flowing to Dry), while in RMR89, the range is 4-15, making the Indian standard more punitive for wet conditions and less rewarding for dry conditions.
≠The international standard RMR89 provides more detailed and specific adjustment tables for discontinuity orientation based on the type of structure (tunnels, foundations, slopes), whereas IS 10042 provides a more generalized adjustment.
≠IS 10042:1981 has not been updated since its publication, whereas the international systems (RMR, Q-system, GSI) have undergone continuous refinement based on global case histories and research.
Key Similarities
≈Both IS 10042 and international systems like RMR share the same fundamental purpose: to classify rock mass into categories of behavior for civil engineering design, particularly for tunnels and foundations.
≈The core set of input parameters is almost identical, including: strength of intact rock, Rock Quality Designation (RQD), spacing of discontinuities, condition of discontinuities, and groundwater conditions.
≈Both systems use a summative rating approach where individual parameter ratings are added to arrive at a final numerical score (the RMR value).
≈The final numerical rating in both the IS code and RMR89 is used to group the rock mass into five classes (from Very Good to Very Poor) to provide preliminary estimates of engineering properties and support requirements.