SAMPLING OF SAND AND MORAINE WITH THE SWEDISH FOIL SAMPLER

BY COMBINING ROTARY DRILLING WITH SAMPLING WITH THE SWEDISH FOIL SAMPLER IT IS POSSIBLE TO OBTAIN UP TO 10 M LONG CORES OF COHESIONLESS SOILS AND MORAINES EVEN BELOW THE GROUND WATER TABLE. HARD STRATA CAN ALSO BE PENETRATED. DRILLING MUD IS USED TO STABILIZE THE BOREHOLE AND TO PREVENT LOSS OF THE SAMPLE DURING THE WITHDRAWAL. THE DRILL TUBE WHICH IS PROVIDED WITH AN OVER-SIZE DRILL BIT WITH HARD CARBIDE INSERTS IS ROTATED BY AN ELECTRICALLY DRIVEN ROTARY TABLE. THE DRILLING RATE VARIES NORMALLY BETWEEN 2 AND 5 M/HOUR. THE DRILL RIG IS OPERATED BY ONE FOREMAN AND THREE HELPERS. /AUTHOR/