<p>In this work, the attenuation behaviour of naturally available river sand subjected to blast waves created using a vertical shock tube in a laboratory setting using compressed helium gas is studied. Among the number of granular media, river sand is commonly used to protect critical installations against devastating ground vibrations caused due to blast waves. It is crucial to note that the attenuation behaviour of soil in general is site specific and that full-scale field experiments are conventionally carried out to obtain the ground shock parameters like peak pressure and their attenuation along propagation distance, which are time-consuming, are expensive, and have significant environmental impact. In comparison, the vertical shock tube used here not only reduces the experimental time, costs, and risks involved but also ensures the repeatability of tests and reduction in sensor damage. The attenuation behaviour of the peak pressure in a sand column in a test chamber, at low, medium, and high relative density values, subjected to blast waves of varying intensities and decay times is studied presently. It is observed that the peak pressures measured at various locations in the sand column and peak overpressure in the air just above the free surface of the sand sample attenuate exponentially. It is also observed that the attenuation of blast wave is more pronounced for sand samples with medium relative density (43% RD) as compared to low (25% RD) and high relative densities (67.5% RD) considered in this work. It is postulated that particle interlocking primarily governs the attenuation of blast waves at lower relative densities, while the collapse of void volume governs it at higher relative densities, and a combination of the two leads to slightly higher attenuation in medium relative density sand samples.</p>