Saravanan Swaminathan

USING MECHANICAL ENERGY AS A PROBE FOR THE DETECTION AND IMAGING OF SHALLOW BURIED INCLUSIONS IN DRY GRANULAR BEDS

Mechanical energy, such as sound waves and impulses, have been used to detect shallow buried objects for more than half a century. Yet, very little is understood about how mechanical energy propagates into one of the simplest kinds of soil, namely, a granular bed. Here we present an overview of the state of the art in our understanding of mechanical energy propagation in granular beds.

Detection of shallow inclusions in closed-packed granular beds using mechanical impulses

Mechanical energy has been used in the detection of shallow buried objects in granular beds for more than half a century. Here we attempt to answer a fundamental question—at what depths would an object be detectable in an idealized, close-packed, granular bed made of monosized elastic spheres? Systematic particle dynamics based studies reveal the effects of varying the area across which the impulse is generated, object size, and restitution on locating the buried object.

Acoustic interrogation of soil and possible remote detection of shallow buried inclusions

Here we address the problem of remotely interrogating the shallow subsurface of soil using low power mechanical energy transmission and sensing the subsequent backscattering from the soil bed to find small buried objects at very shallow depths (~ 15 cm or less). The effort is geared towards the development of better technologies for the remote detection and imaging of buried land mines, improvised explosive devices (IEDs) and other undesirable objects. We present our studies against the backdrop of what is known in this field today. Our ongoing work is briefly summarized with an outline of the underlying physics of acoustic backscattering from shallow buried objects and of how such backscattering can be inexpensively and remotely detected and interpreted for possible use in automated mine clearance operations.