MEASUREMENT OF THICKNESS OF SOIL RAKED OUT IN SOFT GROUND SURFACE LAYER TREATING WORK

摘要

PURPOSE:To raise the accuracy of construction work by a method in which a waves sender whose waves-sending face is directed to the underground and a receiver of reflected waves are provided on a truck, and the thickness of soil raked out is detected by time lag between waves-sending signal and waves- receiving signal. CONSTITUTION:An air-permeable sheet 3 is buried between supersoft ground 1 and good-quality soil 2, and a truck 4 is set on the soil 2 in a traveling manner. A laser level meter 5 is fixed and the truck 4 is provided with a received light level sensor 7, a waves sender 11, and a waves receiver 12. Output of an oscillator 10 is sent into the ground by the waves sender 11, reflected waves from the sheet 3 are received by the receiver 12, and the outputs of the sender 11 and the receiver 12 are calculated as a time lag in a time lag sensor 13. Laser from the level meter 5 is detected by the sensor 7 and supplied through a photoelectric converter 8 to the sensor 13 and a substraction unit 9. The results are sent out to a displayer 16 and a recorder 17.