Full formScience
RQDstands forRock Quality Designation
Full Form of RQD
What is RQD?
Rock Quality Designation, commonly abbreviated as RQD, is a fundamental geotechnical parameter used to assess the quality and integrity of rock masses in mining and civil engineering projects. Developed by Deere and Deere in 1964, RQD is calculated as the percentage of intact rock core pieces longer than ten centimetres recovered from a borehole, relative to the total length of the drill run. The metric plays a vital role in India's infrastructure sector, particularly in the design of tunnels, dams, highways, metro rail projects, and underground mines across challenging terrains like the Himalayas and the Western Ghats. Geologists, mining engineers, and civil engineering professionals rely on RQD values to classify rock masses for stability analysis, support design, and excavation planning. Higher RQD values indicate better rock quality and fewer discontinuities, while lower values suggest fractured or weak rock. The concept is regularly tested in competitive examinations such as GATE, UPSC, SSC-JE, and various state-level engineering recruitment tests, making it essential reading for aspirants preparing for technical roles in geology and civil engineering.
RQD का फुल फॉर्म
चट्टान गुणवत्ता पदनाम
Example
The geotechnical team reported an RQD of 78% from the borehole samples at the Chenab River railway bridge site, indicating moderately good rock quality suitable for the massive pier foundations.
RQD — frequently asked questions
What is the full form of RQD?
RQD stands for Rock Quality Designation, a geotechnical index developed in 1964 to measure the quality of rock mass from borehole core samples.
How is Rock Quality Designation calculated?
RQD is calculated as the sum of lengths of intact rock core pieces longer than 10 cm, divided by the total length of the drill run, expressed as a percentage.
Why is RQD important in Indian civil engineering projects?
RQD helps engineers assess rock stability for tunnels, dams, highways, and metro projects in India, guiding excavation methods, support systems, and ensuring safe construction in hilly and mountainous regions.