The use of a coupler in the conversion of impact energy into seismic energy

The factors which influence the efficiency of generation of seismic energy by a falling weight‐coupler system have been investigated both theoretically and experimentally using model techniques. Two media, sand and clay‐silt‐sand, were used. Source conditions were changed by (1) varying the mass of the falling weight, (2) varying the drop‐height, and (3) embedding various bodies (couplers) at the impact point. The results showed that for compressional waves: 1. A∝M23Vc where A is the amplitude of the seismic signal, M the mass of the coupler, and Vc the maximum speed of the coupler. 2. The seismic energy is not proportional to the source energy. 3. In general, for a given source energy the larger the falling mass the more efficient is the generation of seismic energy. 4. The coefficient of restitution between the falling mass and coupler can be determined from seismic‐wave amplitudes. 5. Complex waves can be generated when the mass of the falling weight is greater than that of the product of the mass of t...