Bedrock geometry determination for conduct construction

Prior to the construction of a water conduct, geotechnical studies showed strong variations for Molasse depth. In order to precisely determine its geometry and support borehole data interpretations, a refraction seismology profile was acquired.

The 360m profile was acquired in one day by a small team comprised of an engineer geophysicist, an assistant geophysicist, a topographer and a helper.

This seismic section upheld borehole data, all the while specifying significant thickness variations in the Quaternary cover.

A strong bedrock topography is clearly shown by the refraction seismic processing

The acquired seismic profile confirmed the presence of a significant spur in the Molasse. The correlation proved excellent between borehole data and the seismic profile.

The seismic shotgun is a lightweight, secure but strong energy source
Location Switzerland
Instrument Geode
Geometry 72 geophones, 5m spacing
Positioning DGPS
Source Seismic gun
Length 360 meters
Personnel 4 people
Duration 1 day