Re-Evaluation of the Rammsonde Hardness Equation

• Published in: Journal of Glaciology
• Main Author: Waterhouse, R. W.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 1966
• Subjects: Earth-Surface Processes; Journal of Glaciology
• Online Access: http://dx.doi.org/10.1017/s0022143000019547; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000019547

Penetration tests in snow show that the Rammsonde number R as a measure of force resisting penetration may be in error by a factor of two depending on the ratio of hammer to probe weight and the coefficient of restitution. It is suggested that the Hiley pile driving formula is applicable to the problem and gives more accurate values for the force of penetration. This formula accounts for the influence of different hammer weights, is in agreement with the conservation laws to the first approximation, and has been in general use for some time as one of the best simple equations for determining the dynamic resistance of piles. The Rammsonde equation is notable for its simplicity. The Hiley equation, using the same factors does not detract from this virtue. Further research is suggested to find ways of replacing the coefficient of restitution with more fundamental parameters in impact problems.