On the height of fall of dropping mass in SASW measurements for asphaltic road pavements

Abstract

A number of spectral analysis of surface waves (SASW) tests were performed on asphaltic road pavements by dropping a metallic 6.5 kg sphere, from a height (H) ranging from 1 to 3 m. Various combinations of source to first receiver distance (S) and receiver spacing (X) were employed. By increasing the height of the fall of the dropping mass, the maximum wavelength (λ_max), up to which the shear wave velocity profile can be predicted with the usage of the SASW measurements, was found to increase continuously. The height of fall of the dropping mass also seems to affect the admissible range of the wavelength for given combinations of X and S. Irrespective of different chosen combinations of S, X and H, a unique combined dispersion curve was generated in all the cases for a given pavement site as long as the threshold minimum value of the coherence function is greater than 0.90.

Keywords:

• geotechnical engineering
• non-destructive testing
• SASW
• pavements
• wave propagation

Acknowledgement

The financial support provided by Ministry of Shipping, Road Transport and Highways, New Delhi, India, under the research scheme ‘Testing of pavements using seismic waves’ is gratefully acknowledged.