Pirotechnic dynamic penetration measuring and testing apparatus for soil test

Date of filing: 10 December 1991

Priority: 12/12/99 (90/15512), FR

International Application Number: PCT / FR91 / 00997

International Publication Number: WO 92/10753

BACKGROUND OF THE INVENTION The present invention relates to pyrotechnic dynamic penetration measuring and testing apparatus for soil detection, which is suitable for soil recognition and soil properties.

Soil detection systems known hitherto can generally be classified into one of two known test systems, namely one for soil measurement by pressure measurement or by means of a penetration meter, in particular a dynamic penetration meter.

The essence of dynamic penetration measurement is that a depth gauge • ·

- Determines the kinetic energy needed to lower 2 at a certain height. Kinetic energy is usually generated by a calibrated drop in a given mass.

Measurements made with this system can take a long time, and in our age when wage costs are high, especially costly.

In addition, known systems of this kind do not include automatically displaying the properties of soil types, which would make the measurements performed more reliable.

The object of the present invention is to overcome the shortcomings of the known systems and to develop a pyrotechnic dynamic intrusion detector which meets the following main requirements in particular: fast execution, cost reduction, and ensuring the accuracy of the measurement.

The object of the present invention is to achieve the object of the present invention by continuously plunging a depth gauge rod into the soil to determine soil properties. It penetrates using pressure created by a pyrotechnic gas generator. The idea of ​​the invention is based on using the pressure created by the pyrotechnic gas generator in a discharge tube which facilitates the insertion of a depth gauge rod into the soil.

In accordance with its object, the pyrotechnic dynamic penetration measuring and testing apparatus of the present invention for soil testing is configured to include a guide tube, a depth gauge rod movable relative to the guide tube, a pyrotechnic gas generator, and display units wherein the gauge bar is through a pyrotechnic gas generator

- drill into 3 soils, and where the display units are mounted on the guide tube, each component of the display unit is capable of providing accurate measurement results when penetrating the depth gauge into and through the soil.

According to a further feature of the invention, the movement of the depth gauge rod is indicated by the passage of a magnet which is secured to the depth gauge rod and the depth gauge rod is guided in a guide tube and the display unit sensor is a cylindrical coil ).

Continuous indication of the displacement of the depth gauge bar in the conducting ejector tube, by the motion of the magnet, is a solenoidal coil disposed along the length of the conducting tube as a motion sensing member. Optionally, the sensing organ is supplemented with an electronic information processing unit.

For a lightweight and portable system, the device balances motion with a kickback mass that moves vertically. In a preferred embodiment, a portion of the rebound mass preferably serves as both a gas expansion chamber and a guide for the depth gauge rod.

According to another aspect of the invention, the display unit comprises photoelectric cells or electromechanical contacts for detecting movement of the depth gauge bar.

The soil testing apparatus according to the invention comprises an electronic information processing unit in which the parameters of the apparatus, in particular the coordinates of the movements of the depth gauge rod

<img file="HUT64622A_D0001.tif" />

they swear in advance. pre-programmed so that soil characteristics can either be directly displayed or available for evaluation or printing.

The measurement result of the soil test is evaluated by means of a pre-programmed electronic circuit, continuously calculating the result of the acceleration measurement of the displacement. The point of this is that the result of the acceleration of displacement is equal to the result of the acceleration measurement created by the gas pressure on the depth gauge and the resistance of the soil on the same rod.

In order to evenly distribute the amount of motion transferred to the depth gauge rod, a back mass is placed in the guide tube whose kinetic energy is used to overcome the kinetic energy due to gravity. In a preferred embodiment, the recoil mass also serves as a tube and / or an expanding chamber for the depth gauge bar. A further criterion is that the repulsion mass includes the pyrotechnic gas generator chamber.

In a preferred embodiment, the recoil mass is provided with one or more safety drainage openings at the height of the expanding chamber and that the guide tube also has an additional borehole as an additional opening to assist gas release in case the depth gauge rod becomes stuck in the soil prematurely. .

According to another embodiment of the invention, the device comprises a hollow depth gauge rod extending along a movable guide tube, the guide tube in the reciprocating mass being a clamping chuck or a quick release fastener.

- Fixed by 5 systems.

It is a further feature of the invention that the depth gauge rod is made up of several sections which are interconnected by a locking-fitting device during the measurement operation.

According to any of the features of the soil tester, the gas generator is made of thermoplastic or composite materials and its low pressure chamber opens outwards.

The invention will now be described in more detail with reference to the accompanying drawings, in which:

First FIG. 3B is a simplified embodiment of the system of the present invention; FIG

Second Figure 4A shows a more specific system designed for low depth measurements;

Third Figures 4 and 4 show a special system designed for higher depth measurements.

Figure 1 shows a basic version of the penetration measuring and testing device developed for soil testing.

The depth gauge rod 1 is secured to a plunger 2 in which a magnet 3 is placed.

A gas generator 5 is formed inside the recoil mass 4. Neutralization of rebound energy is provided by gravity. However, without going beyond the scope of the invention, it will be appreciated that other means may be employed to balance the power of the bounce, such as energy neutralizers, such as carrier mass.

<img file="HUT64622A_D0002.tif" />

The depth gauge rod 1, the piston 2, the recoil mass 4 and the gas generator 5 are arranged together in a guide tube 7 which is also a reciprocating tube. The conductive tube 7 consists of non-magnetizable materials. The guide tube 7 is provided with solenoid coils, which are preferably arranged in a circular circumference around the guide tube 7. These solenoid coils form the sensor of the display unit 6. The display unit 6 is connected to the electronic information processing unit 9.

After ignition, the gas generator 5 generates energy through its expansion chamber 8, which is located between the piston 2 and its reciprocating mass 4. The expansion energy moves the depth gauge bar 1 under pressure. In parallel with the firing of the depth gauge rod 1, the motion of the magnet 3 generates electrical signals at different positions of the solenoid coil, whose intervals of appearance can be measured, thus enabling the instantaneous velocity and then acceleration of the depth gauge rod 1 to be calculated.

The change in pressure produced by the gas generator 5 over time is known in the expanding chamber 8 to be measured p (t) or relatively well known by the calculation of the power of the gas generator 5 employed, with an error of 2-3%.

Thus, the force of deceleration caused by the resistance of the ground upon penetration of the depth gauge rod 1 can be determined by the following law:

^R(T) ^s 'P (t) ^m '9 (t)^; ···· • · • · • · ·

<img file="HUT64622A_D0003.tif" />

where is the mass of the depth gauge bar today;

g (_tj acceleration that changes with time;

S is the effective surface of the expansion chamber relative to the piston surface and subjected to pressure;

P (_tpressure over time in the expanding chamber;

R (_t) the force causing the deceleration.

The calculations are performed either by an adapted logic system or by a pre-programmed algorithm system.

Without going beyond the scope of the invention, other systems of this type can be used to indicate the passage, such as electromechanical contacts or photoelectric cells.

Similarly, without going beyond the scope of the invention, a portion of the passage detectors and a portion of the information processing circuit may be replaced by an accelerometer.

Depending on the type of measurement to be performed, the depth gauge rod 1 may be provided with a pressure relief end 10.

Figure 2 is a schematic diagram of a system of the invention for use in portable and especially shallow depth measurements.

The depth gauge rod 1 is secured by a piston 2 in which a magnet 3 is placed. The recoil mass 4 balances the number of movements transmitted to the depth gauge bar 1 and its piston 2. The repulsive mass 4 preferably consists of a tube made of antimagnetic materials, for example, a tube made of antimagnetic materials.

- at the upper end 8 of a closed cylindrical tube, so that the 4 recoil masses also serve as a discharge tube.

Prior to lowering, the depth gauge rod 1 with piston 2 is held back in the recoil mass 4, preferably by a adjustable clip, but without exceeding the scope of the invention, other fastening devices such as a cylindrical spring or a plate spring can be used.

The bounce mass 4 rolls in a conductive tube 7 consisting of antimagnetic materials, preferably of thermosetting or thermoplastic laminated glass fiber composite.

The pyrotechnic dynamic penetration probe, where it is in contact with the ground, is preferably provided with a support 17, which in turn is provided with a retarder 16 which prevents the reciprocal mass 4 from falling back.

The coils 6 of the magnet 3 are preferably located around the guide tube 7 and are connected to the electronic information processing unit 9.

The above sensing and information processing system may be completely self-contained, with only a folding and adjustable tripod 22.

This rack 22 may consist of a ring 18 fitting the three legs 19 together. The length of the legs 19 can be adjusted, for example, by a locking adjusting screw thread 20 and supported by the soles 21 on the ground. The soles 21 may be drilled to possibly anchor the entire system to the ground.

The recoil mass 4 is preferably located at the top of the support base 17 of the gas generator 5 and its starter safety unit 13.

···· · ·

The gas generator 5 is usually started by stroke or shock, but electric or laser beam start can be used.

The gas generator housing 5 preferably consists of a thermoplastic thermosetting resilient plastic or composite material and is constructed so that its operating chamber opens outward to a low pressure space for safety reasons, for example in the event of accidental ignition or fire.

In order to facilitate a better distribution of the load and to ensure safety, the gas generator 5 is preferably housed in a cavity 12 housed in a movable carrier frame 11.

The insertion of this movable carrier frame 11 into the housing 14 allows the gas generator 5 to be operative against the inlet duct of the expansion chamber 8 and at the same time to secure the starter safety unit 13. Also in the embodiment of Fig. 2, the depth gauge rod 1 is provided with a pressure relief end 10.

Without going beyond the scope of the invention, a plunger 2 acting as a jet piston of another configuration may be used.

Fig. 3 shows a special variant for high depth measurements, which is formed by one or more connected depth gauge bars.

The projecting and guiding role of the depth gauge rod 1 is not provided by the piston 2 used in the previous embodiments, but by the closed end of the hollow depth gauge rod 1 which is formed by an overpressure discharge end and by an axial tube along its length. rod. The end of the depth gauge rod 1 may be overpressure

<img file="HUT64622A_D0004.tif" />

without drainage vent.

The depth gauge rod 1 is provided with a head portion 25 which limits the depth gauge rod 1 from sinking into the ground when the excess energy obtained from the gas generator 5 is significantly greater than the energy required for sinking into the ground.

The magnets 3 are located in this head section 25. Here, the rollers of the display unit 6 are disposed about the length of the guide tube 7 in a plane perpendicular to the direction of movement of the depth gauge bar.

The hollow depth gauge rod 1 moves along a guide tube 27 which is connected to the kickback mass 4 by means of a clamp 26, which together with the kickback mass 4 also forms a guide tube 27. The conduit 27 is in communication with the expansion chamber 8 and the gas generator 5. Without exceeding the scope of the invention, the dipstick 1 may also be positioned inside the guide tube 27.

In the upper part of the kickback guide tube 7 there is a bore opening 29. In addition, the expansion chamber 8 has one or more drainage openings 28 which are provided with a safety valve or a diaphragm for opening at a given pressure.

In fact, in the event that the depth gauge rod becomes jammed, the gas generated in the soil must be vented from the expansion chamber 8 in order to limit the re-emergence of the repulsive mass 4.

The gas evacuation is preferably accomplished by means of said borehole 29 and vent 28. They must be designed in such a way as to weaken only slightly the complete performance of the gas generator.

Figure 4 shows that the reciprocating guide tube 7 and the tubular portion of the reciprocating mass 4 have an opening, which is closed by a door 30, which allows filling of the depth gauge rod 1 provided with the guide tube 27. This opening is closed during operation by said door 30 or by rotation of the recoil mass 4 in the guide tube 7.

In the presence of the door lock 30, the depth gauge rod 1 is provided with a latch 31 which is preferably connected to the safety ignition and extinguishing means 15 for safety reasons.

If the depth gauge bar 1 is only partially or difficult to sink into the ground, then it may be easy to lift it out or to drill with the help of another gas generator 5.

To lift the depth gauge rod 1, it is sufficient to open the clamping chuck 26, whereby the guide tube 27 falls to the bottom of the depth gauge rod 1 to release the assembly and then pull out the depth gauge 1, possibly using a gripping device resting on the header 25.

Alternatively, it is also possible to insert another extension rod to further deepen the measuring range. This is done by securing it in place of the head part 25 after removing the guide tube 27.