Variable energy dynamic penetrometer for determination of soil density, in which deformation of constraint gauges in a Wheatstone Bridge is converted into an electric signal which varies in proportion to shock load

摘要

The percussion head (1) has at least an annular ring (15) in its section which defines an annular slot (16) in which is fitted a constraint gauge. Deformation of the gauge under shock load is translated into an electric signal which varies proportionally to the shock load intensity. Four constraint gauges are mounted in a Wheatstone Bridge on the surface of the annular slot, to the right of the annular slot. Method for measuring soil compactness, using a penetrometer fitted with a percussion head (1) made from a high modulus of elasticity material. The penetrometer has a conical probe (2) which transfers energy to the percussion head, which has a diameter about 15 mm. The method determines the energy received by the penetrometer by measuring the deformation of at least a part of the percussion. The deformation is converted into an electric signal which represents the energy received. The penetrometer can include an accelerometer emitting a signal proportional to shock intensity..