Investigations by the method of refracted and reflected waves at the Inambari river valley (Department Madre de Dios, Peru)

Seismic sections across the river at the project sites of hydroelectric power plant dam

The works included profiling by method of refracted waves on the sides of the mountain valley, along the banks and across the riverbed, as well as working out CDP profile by method of reflected waves on the road along right bank across the projected dam. For registration of elastic waves at the land sites 48-channel geophone arrangement was used with channel increments of 5 m. On the riverbed signal reception was carried out using floating or stacked on the bottom hydrophone streamers with a piezoelectric pressure sensors. For excitation of oscillations explosions of dynamite charges weighing 200-600 g were applied.

Rock outcrops and compression modulus section on seismic data through the range of project dam

Below the dam design, a wide area of weathered bedrock argillites with weakened strength properties appears in the section.