Abstract

The invention concerns a method for measuring the elasto-plastic properties of soil, using a static penetrometer provided with a hollow tube surrounding a central rod capable of sliding inside the hollow tube and terminated at a first end by a measuring tip, the method comprising the following steps: a) Driving the pair formed by the hollow tube and the central rod into the soil, in order to bring the measuring tip to a desired depth for measuring the elasto-plastic properties of the soil, the measuring tip being in abutment against the hollow tube; b) Applying a first constant force to a second end of the rod, for a determined period; c) Measuring a first final movement, associated with the measuring tip being driven into the soil, at the end of the determined period; d) Repeating steps b) and c) with successive increasing forces, in order to form a curve representing the final movement as a function of the force, until an nth force is reached leading to an nth final movement, the nth final movement being the maximum and reflecting the tensile strength of the soil; e) Extracting a modulus of deformation of the soil from the slope of the curve, in a first elastic domain located before an inflection point.

IPC Classes  ?

• G01N 3/08 - Investigating strength properties of solid materials by application of mechanical stress by applying steady tensile or compressive forces
• E02D 1/02 - Investigation of foundation soil in situ before construction work
• G01N 33/24 - Earth materials

Abstract

The invention relates to a penetrometer (100) for statically measuring the penetration resistance of ground, comprising at least one central rod (1) ending at a first end in a measuring tip (11) and at least one hollow tube (2) surrounding the central rod (1) and inside which this rod is able to slide. The penetrometer (100) is notable in that the hollow tube (2) comprises: • a first part (21) comprising at least one seal (24) between its internal wall and the central rod (1), • a second part (22) having a diameter (d2) smaller than that (d1) of the first part (21) and into which a fluid (41) is intended to be injected; • at least one expulsion orifice (23) situated between the first (21) and the second (22) part, the said fluid (41) being intended to leave via the expulsion orifice (23).

IPC Classes  ?

• G01N 3/08 - Investigating strength properties of solid materials by application of mechanical stress by applying steady tensile or compressive forces

Abstract

The invention relates to a penetrometer (100) for evaluating the liquefiable character of a soil, comprising: • at least one central rod (1) terminated at a first end by a measuring tip (11); • at least one hollow tube (2) surrounding the central rod (1), the latter being capable of sliding inside the hollow tube (2). The penetrometer (100) also comprises an electrical cylinder (6) comprising an external body (61) solidly attached to the hollow tube (2) and a movable body (1), said movable body (1) being: • configured to transmit a movement to a second end (12) of the central rod (1) leading to a controlled pressing of the measuring tip (11) into the soil, and to measure a force applied to produce said movement, • and suitable for applying a vibration at a determined frequency to the second end (12) of the central rod (1).

IPC Classes  ?

• E02D 1/02 - Investigation of foundation soil in situ before construction work

Abstract

The invention concerns a penetrometer (100) for static mode measurement of the penetration resistance of a soil, comprising: • at least one central rod (1) terminated at a first end by a measurement tip (11); • at least one hollow tube (2) surrounding the central rod (1), the latter being able to slide inside the hollow tube (2); • a measurement cell (3) in contact with the hollow tube (2), for transmitting a force applied by support means, in such a way as to cause a driving into the soil of the hollow tube (2) and of the central rod (1). The penetrometer (100) further comprises: • a calibrated compressible device (6) providing a resilient connection between the measurement cell (3) and a second end (12) of the central rod (1); • a movement sensor (7) capable of measuring the length of the calibrated compressible device (6); and • additional driving-in means (8) capable of applying a vibration to the hollow tube (2) at a determined frequency.

IPC Classes  ?

• E02D 1/02 - Investigation of foundation soil in situ before construction work
• G01N 3/10 - Investigating strength properties of solid materials by application of mechanical stress by applying steady tensile or compressive forces generated by pneumatic or hydraulic pressure