Impact generator for seismographic measuring - has ground contact member in form of cushion, filled with water, and with high tensile strength walls

摘要

The impact generator has a ground contacting member in the form of a cushion (2) which can be filled with water and has walls of considerable flusile strength, pref. giving a flat, rectangular cushion cross section. The contacting member may be divided in several cushions. The upper edge of each cushion may have a peripheral flange (5), serving for fastening on a rigid plate (1), e.g. by screws and bars. The cushion may comprise a pressure-tightly closable container (3,4,12). The height to width ratio of the cushion (5) is typically 1:10. Each cushion has a filling branch and an air vent. Inside each cushion may be inserted a porous, elastic substance (6), such as sponge rubber.