Ultrasonic Pulse Velocity of Rock(ISRM Suggested Method)
P-wave and S-wave velocity measurement on rock cores per the ISRM Suggested Method — deriving dynamic elastic moduli and flagging micro-fracturing and weathering non-destructively.
What is the Ultrasonic Pulse Velocity Test of Rock?
Sound travels faster through intact rock than through fractured or weathered rock — making ultrasonic pulse velocity the most efficient non-destructive index of rock quality. Measuring P-wave (and where equipped, S-wave) transit times through a prepared core yields velocities that, combined with density, give the dynamic Young's modulus and Poisson's ratio, and correlate with strength, weathering grade and micro-crack density. Indian lab practice follows the ISRM Suggested Method for laboratory sonic velocity (IS 13311 Part 1 covers the concrete analogue).
Global Lab measures transit times with calibrated transducers under controlled coupling and axial seating pressure, reports Vp (and Vs) per specimen with dynamic moduli, and — tested alongside static modulus (IS 9221) — provides the dynamic-to-static ratio designers use in fractured rock masses.
How the Ultrasonic Pulse Velocity of Rock is Conducted
- 1
Specimen Preparation
Cores are cut with flat, parallel end faces; length and density are measured precisely. - 2
System Calibration
Transducer zero-time is verified on a reference bar before each series. - 3
Transit Time Measurement
P-wave (and S-wave where specified) transit times are measured under standard coupling and seating pressure. - 4
Velocity & Moduli Computation
Vp and Vs are computed from path length and time; dynamic E and ν are derived with density. - 5
Reporting
Velocities, dynamic moduli and quality interpretation are issued via Autovity QLMS.
Applicable Test Standards
| Standard | Title | Scope | Type |
|---|---|---|---|
| ISRM SM | ISRM Suggested Method for Determining Sound Velocity of Rock | Test Method | International |
| IS 9221:1979 | Method for Determination of Modulus of Elasticity and Poisson's Ratio of Rock (Reaffirmed) | Static Companion Test | Indian Standard |
| IS 13311 (Pt 1):1992 | Non-Destructive Testing of Concrete — Ultrasonic Pulse Velocity (Reaffirmed) | Concrete Analogue (Reference) | Indian Standard |