JPH0819819B2 - Device and method for hydraulic testing and / or grouting in a borehole - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to an apparatus and a method for performing a hydraulic test and / or grouting in a borehole.

[Conventional technology]

Generally, a hydraulic test in a boring pit, which aims to determine the permeability of a section of soil, isolates the part of the boring pit across this section and then measures the water flow pressure into the water. Consisting of injecting. This work actually stops the boring at the bottom of the section you want to test, raises the boring device, lowers the injection pipe with the obstruction device inside the borehole, and wants to test this obstruction device Positioned at the upper level of the section considered, thus forming a test chamber between the closure device and the borehole, injecting water through the injection pipe into this chamber, and then the passage of time. It is realized by reading the flow rate and pressure as.

Therefore, such a test is time consuming as it requires the complete raising of the row of boring rods and the installation of the injection tube and the occluding device. The deeper the borehole, the longer and more expensive these operations will be.

The same applies to the case where it is desired to perform the grounding while excavating in the soil. The row of boring rods must be raised after each grouting.

[Problems to be Solved by the Invention]

The object of the present invention is to eliminate the above-mentioned drawbacks by providing a device and a method which make it possible to carry out grouting during hydraulic testing and / or excavation without having to raise the boring device.

[Means for Solving the Problems] Therefore, the present invention provides an apparatus for performing a water pressure test and / or grouting in a boring pit, the apparatus including a rod row having a boring tool attached to a lower end thereof. A boring system having a rod of one of said rods provided with an inflatable closing sleeve around said rod, said rod of rods having a first refill duct open at the bottom over its entire length. And also
A boring system having a second supply duct for inflating the closure sleeve over a portion of its length overlying the closure sleeve, the apparatus comprising the first duct; An apparatus is provided further comprising means for injecting a fluid therein and means for measuring the flow rate and pressure of the infused fluid.

If the rod with the closing sleeve is arranged directly above the tool, then only the height of the rod row has to be raised to define the height of the hydraulic testing chamber. However, if it is certain that there is a minimum height at this height, then every ascent can be achieved by placing the rod with the closure sleeve at a distance from the boring tool equal to this minimum height. Can be avoided. Even in this case, it is possible to obtain a higher chamber height by raising the rod row to some extent. Even if it is considered to be for grouting, the rod with the closing sleeve is arranged at a certain distance from the boring tool.

In either case, the first duct is used for replenishment of drilling fluid during boring, water during hydrostatic testing and replenishment of grout during the grouting phase.

The other duct is for inflation of the closure sleeve only.

These two ducts may be concentric, especially in the part of the row of rods which is above the closure sleeve.

In a particular embodiment spacers are arranged on the row of rods on both sides of the rod with the closing sleeve.

The role of these spacers is to center the rod with the blocking sleeve in the borehole to avoid premature wear of the blocking sleeve due to friction on the boring wall.

More specifically, these spacers, especially those mounted underneath the rod with the closure sleeve, consist of a digging sleeve to smooth against the boring wall before the closure sleeve passes through. May be done.

One particular embodiment of the present invention will now be described, by way of non-limiting example, with reference to the accompanying drawings.

[Embodiment]

As shown in FIG. 1, the device comprises a boring system having a row of rods or rod rows 1 suspended by a boring head 2, the boring head 2 on the one hand a rotary drive of the rod rows 1. On the other hand, it is possible to replenish the drilling fluid from the pump 3 via the pipe 4 connecting the boring head 2 and the pump 3.

In addition, a clamp 5 is provided in a known manner to allow the addition of new rods, especially during boring.

The row of rods 1 has in its lower part a boring tool 6 adapted to the soil to be excavated, for example a "rotary" type tool such as a tricone (a drilling tool with three conical drill bits) or soft soil. Cutter tools for drilling, or bottom hole hammers for hard soil, or any other known drilling tool.

The rod array 1 has a rod 7 with an inflatable closing sleeve 8 in its middle part.

The pump 3 has a flow rate 10 of the fluid injected into the rod array 1.
And a measuring and recording device 9 which makes it possible to measure and record the pressure 11. This measuring and recording device 9 may especially be integrated in the boring parameter recording mechanism. In this case, the recording mechanism has two functional modes, namely the measured parameters are, for example, the depth of the boring, the force exerted on the boring tool 6, the drilling advance speed, the rotational torque exerted on the tool 6, the rotational speed. , The injection volume and pressure of the drilling fluid, or the "parameter recording" mode, which is all other boring parameters such as reflex vibration, back pressure exerted on the tool 6, boring time etc. "Hydraulic test recording" mode as is the flow rate and pressure of water injected into the train. Integrating the device 9 in this way in one boring parameter measuring mechanism has the advantage that the boring parameters allow to determine in real time which boring stage a hydraulic test or grouting is required.

FIG. 2 shows a certain number of rods connected to the boring head 2 and continuously above the expansion sleeve 12 and rods 7.
13, a digging sleeve 14 with a digging cutter 15, a rod 7, a second digging sleeve 16, a certain number of rods 17 under the rod 7, and a rod having a boring tool. Column 1 is shown.

The elements of the rod array 1 above the rods 7 include two concentric ducts, a cylindrical central duct 19 and an annular duct 20. Duct 19 is an injection duct for the boring head.
Connected to 21, leading into the bottom of the row of rods and opening into the borehole at the level of the boring tool 6.

In contrast, the duct 20 is restricted to the upper part of the row of rods. The duct 20 is open at its top at the level of the expansion sleeve 12 via a push-pull type fitting, where the duct 20 pumps 23 via a pressure control device 25 with a gate valve 24 and a pressure gauge 26. Can be connected to. The lower part of the duct 20 opens at the level of this rod 7 between the closing sleeve 8 and the rod 7 in a manner that allows the closing sleeve 8 to expand.

The closing sleeve 8 is fixed to the rod 7 at its both ends and arranged on the periphery of the rod 7, and is made of an elastic material exhibiting excellent resistance to friction. The closure sleeve 8 is preferably provided as compatible.

If it is desired to perform a hydraulic test or grouting during drilling, fix the boring tool 6 to the desired depth and clean the boring hole. Since the rod row 1 is fixed by the clamp 5, it is pumped through the annular duct 20.
23 is used to expand the closing sleeve 8. The inflation pressure is maintained and controlled by the controller 25.

At this time, a hydraulic test or grouting can be started without having to raise the rod row 1 or lower the closing device. This test is for pump 3 and duct 19
Is used to inject water into a section of soil between the bottom of the borehole and the rod 7.

The water pressure test is performed through the same steps as the conventional test,
During these steps, pressure and flow measurements are recorded over time, digitized and stored in the measuring and recording device 9.

At the end of the test, it is only necessary to deflate the closing sleeve 8 via the gate valve 24 and continue drilling.

Therefore, the apparatus according to the present invention can save a great amount of time as compared with the conventional soil investigation method. It is also a valuable aid for hydrostatic test determination and interpretation, as the results are readily available.

It will be appreciated that various changes and modifications may be made to the above description without departing from the scope or spirit of the invention.

For example, unlike the embodiments described above, it is also possible to use a central duct for the expansion of the closing sleeve and an annular duct for the injection.

[Brief description of drawings]

FIG. 1 is a general view of an apparatus according to the present invention. FIG. 2 is an enlarged view of an axial cross section of a rod row used in this device. Numbers of main components 1 ... Rod row, 2 ... Boring head, 3 ... Pump, 5 ... Clamp, 6 ... Boring tool, 7 ...
Rod with inflatable closing sleeve, 8 ... Inflatable closing sleeve, 9 ... Measuring and recording device, 1
4, 16 …… Spacer (expansion sleeve), 19 …… First supply duct, 20 …… Second supply duct.

Claims (6)

[Claims] 1. An apparatus for performing hydraulic testing and / or grouting in a borehole, the apparatus comprising a row of rods (1) having a boring tool (6) mounted at the lower end. Wherein one rod (7) of such a rod row is provided with an inflatable closing sleeve (8) around it, said rod row (1)
Has a first replenishment duct (19) which is open at its lower part over its entire length and over its length above the closing sleeve (8). 8) a boring system having a second refueling duct (20) for expanding the device, said apparatus comprising means (3) for injecting fluid into said first duct; Apparatus for performing hydraulic testing and / or grouting in a borehole, further comprising means (9) for measuring the flow rate and pressure of the injected fluid. 2. The first duct (19) and the second duct (20) are concentric in the portion of the rod row (1) above the closure sleeve. The device according to. 3. Spacers (14, 16) are mounted on the rod row (1) on both sides of a rod (7) with the closing sleeve (8). The apparatus according to 2. 4. The spacer (16) mounted below a rod (7) with at least a closure sleeve (8).
4. Device according to claim 3, characterized in that it is constituted by a digging sleeve (16). 5. A boring system having a row of rods (1) to which a boring tool (6) is attached at its lower end, wherein one rod (7) of such rod row (1) expands around it. A possible closing sleeve (8), said rod row (1) having a first refilling duct (19) which is open at the bottom over its entire length, and
Drilling using a boring system having a second make-up duct (20) for inflating the closing sleeve (8) over a length overlying the closing sleeve (8) and performing a hydraulic test And / or interrupting the boring at the level at which grouting is desired, inflating the closure sleeve (8) through the second supply duct (20), and in the chamber delimited by the closure sleeve (8). A method for performing a hydraulic test and / or grouting in a boring pit, which comprises injecting a fluid through a first supply duct (19) and measuring the flow rate and the pressure of the injected fluid. 6. The method according to claim 5, characterized in that the boring parameters are measured during the boring stage.