Portable motorized pressuremeter and method for calculating in situ soil properties

A method for calculating in-situ soil properties with a portable pressure meter onsite, comprising the steps of:

• coring an approximately 1-inch hole into a soil surface to form a borehole;
• providing a portable ground engaging balloon probe having a diameter of approximately ¾ if an inch, to be inserted into the borehole;
• providing a portable controller unit housing an electric motor with encoder, for running a hydraulic piston pump, a pressure transducer, a data acquisition card, a rechargeable battery power supply for providing power to the electric motor and an exterior water supply
• attaching a controller unit housing connected to a computing device, the controller unit housing an electric motor with encoder, for running a hydraulic piston pump, a pressure transducer, a data acquisition card, a rechargeable battery power supply for providing power to the electric motor;
• providing a portable water supply of up to approximately two gallons;
• connecting the ground engaging balloon probe to the exterior water supply, the probe;
• and
• activating a switch for the controller unit, to cause the electric motor to pump water by the hydraulic piston pump from the water supply to radially inflate the long cylindrical balloon using up to approximately 20 volume increments until the balloon is approximately 50% larger than an initial filled position when the inflated balloon is first in contact with walls in the borehole, and pressure data is recorded at each volume increment, and the computer software accurately calculates soil stiffness and soil strength, from each of the increments in a single operation that runs within approximately ten minutes.