| Description |
viii, 109 leaves : illustrations, photographs ; 29 cm |
| Summary |
"The use of impact energy sources in lieu of explosives for shallow seismic investigations is limited chiefly by the low energy available. Means of increasing the energy transmission of an impact source are investigated, using a weight drop arrangement and an oscilloscope. The energy of refracted arrivals is investigated by direct overburden impacts, compaction of the overburden at the point of impact and the use of steel and aluminum plates as coupling devices. Energy transmission is shown to be greatly increased, using a suitable coupling device and the conditions for optimum coupling are discussed. The elastic constants of the ground in the impact area are presented as a result of P and S wave determinations and density sampling. A seismic refraction apparatus is presented for shallow investigations combining a sledge hammer energy source, a visual display of the seismic arrival, and an electrical counter yielding elapsed times visually. A small scale field problem is discussed using both standard refraction equipment and the devised method. The generation and use of shear waves for shallow refraction investigations is also discussed"--Abstract, leaf ii. |
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