GB2220686A - Hydraulic rock-blasting bore-hole probe and a method for its application - Google Patents
Hydraulic rock-blasting bore-hole probe and a method for its application Download PDFInfo
- Publication number
- GB2220686A GB2220686A GB8816573A GB8816573A GB2220686A GB 2220686 A GB2220686 A GB 2220686A GB 8816573 A GB8816573 A GB 8816573A GB 8816573 A GB8816573 A GB 8816573A GB 2220686 A GB2220686 A GB 2220686A
- Authority
- GB
- United Kingdom
- Prior art keywords
- probe
- rock
- core
- pressure
- bore
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
- 239000000523 sample Substances 0.000 title claims description 43
- 238000000034 method Methods 0.000 title claims description 19
- 238000005422 blasting Methods 0.000 title claims description 13
- 239000011435 rock Substances 0.000 claims description 27
- 229910000831 Steel Inorganic materials 0.000 claims description 21
- 239000010959 steel Substances 0.000 claims description 21
- 238000005259 measurement Methods 0.000 claims description 15
- 239000012530 fluid Substances 0.000 claims description 14
- 238000007789 sealing Methods 0.000 claims description 14
- 238000006073 displacement reaction Methods 0.000 claims description 7
- 239000002689 soil Substances 0.000 claims description 7
- 239000000463 material Substances 0.000 claims description 6
- 229920003023 plastic Polymers 0.000 claims description 3
- 239000002184 metal Substances 0.000 claims 1
- 210000004379 membrane Anatomy 0.000 description 6
- 239000012528 membrane Substances 0.000 description 5
- 238000005516 engineering process Methods 0.000 description 2
- 229920002457 flexible plastic Polymers 0.000 description 2
- 238000005065 mining Methods 0.000 description 2
- 241000173697 Euchloe naina Species 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000007812 deficiency Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 238000007493 shaping process Methods 0.000 description 1
Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B49/00—Testing the nature of borehole walls; Formation testing; Methods or apparatus for obtaining samples of soil or well fluids, specially adapted to earth drilling or wells
- E21B49/006—Measuring wall stresses in the borehole
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21C—MINING OR QUARRYING
- E21C37/00—Other methods or devices for dislodging with or without loading
- E21C37/06—Other methods or devices for dislodging with or without loading by making use of hydraulic or pneumatic pressure in a borehole
- E21C37/10—Devices with expanding elastic casings
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21C—MINING OR QUARRYING
- E21C39/00—Devices for testing in situ the hardness or other properties of minerals, e.g. for giving information as to the selection of suitable mining tools
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
- G01N33/24—Earth materials
Landscapes
- Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Mining & Mineral Resources (AREA)
- Geology (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Health & Medical Sciences (AREA)
- Physics & Mathematics (AREA)
- Environmental & Geological Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Medicinal Chemistry (AREA)
- Remote Sensing (AREA)
- Food Science & Technology (AREA)
- Fluid Mechanics (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Investigation Of Foundation Soil And Reinforcement Of Foundation Soil By Compacting Or Drainage (AREA)
- Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)
Description
2220680 HYDRAULIC ROCK-BLASTING BORE-HOLE PROBE AND A METHOD FOR ITS
APPLICATION The object of the present invention is a hydraulic rock-blasting bore- hole probe which can be applied mainly in mining, geophysical and geological measurements to determine the stress staie of the strata or soil and their modulus of elasticity and, moreover, as a breaker built in break technologies.
Object of the invention is also a method, which enables a measuring process for continuous storage and evaluation of rapidly changing parameters generated by said bore-hole probe.
The determination of the characteristic values of the actual stress state (minimal principal stress, maximal principal stress, the elasticity modulus of the rock) prevailing in the rock is one of the fundamental problems of rock mechanics. These features are determined by the so-called bore-hole probe measurement during which a hole is bored in the rock wall, then a probe is placed in the bore. The flexible jacket of the probe can be pressed to the wall of the bore by increasing the controllable pressure of fluid inside the jacket. Thereafter, the rock wall can be blasted by further increasing the pressure of said fluid. On basis of the fluid pressure needed to blast the rock - 2 and to reopen the blasting the parameters that characterize the st.rcss stpte cf the rock well can be determined. The bore-hole probe applied in the measurements should be expansible under the influence of fluid pressure, therefore it must be made of considerably flexible, high- strength and tough material that has small permanent set and can be re- used.
The flexible jacket of the presently used probes is generally made of rubber which is usually torn up by a pressure smaller than the blasting pressure or it lets the fluid run out at the sealing lock.
Object of the invention is to eliminate the factors that make the measurements and their fidelity untrue by providing a bore-hole probe construction where at the stuffings a sealing can be realized that is equivalent to the strength of the flexible jacket, therefore this reliable stuffing method enables the use of jacket materials of higher strength.
Further object of the invention is to provide a method for continuous sensing and storing the rapidly changing parameters such as the change of the pressure in the probe and the change of the volume of the probe in consequence of the rock pressure.
The flexible jacket of the invented bore-hole probe is made of considerably flexible, high-strength, tough material, suitably adiprene that is able to stand a pressure of more hundred atmospheres without a permanent set and, moreover, such kind of flexible probe jacket does not need additional energy to be blown up without a load that would modify the results of the measurements.
At the probe according to the invention the flexible jacket - membrane is pulled over a steel core so that the sealing strength at both ends of the probe is equivalent to the strength of the probe material. It is ensured by the fact that at both ends of the probe's steel core there are tapering parts at the end of which there are sealing edges formed so that by means of threaded locking nuts and by inserting locking elements the plastic jacket is pressed against these edges. The sealing edges are shaped at the truncated tapering endings of the probe's steel core.
The locking element has an internal tapering shape and it can be pressed against the steel core by a nut. The bevel angle of the internal conical surface of the locking element is suitably greater than the bevel angle of the conical surface shaped on the steel core. The flexible plastic jacket is pressed amongst the two conical surfaces by means of the threaded locking nut.
This sealing method ensures a perfect closing even when an internal pressure of more hundred atmospheres occurs.
On the one hand the invention is a rock-blasting bore-hole probe to be used in determining the strength features of rock walls, in blasting, and in measurements on soil mechanics. It consists of a steel core supplied with an inlet boring and a flexible jacket that covers the surface of the steel core and it Vids sealed closings at the endings. The steel core has truncated tapering endings and two threaded stubs as continuations, the upper endings of the truncated cones are shaped as sealing edges. A locking element is pressed against each threaded stub by means of locking nuts. The locking elements have internal conical surfaces whose bevel angle is greater than that of the steel core; the internal conical surfaces fit into the sealing edges. The flexible jacket that covers the steel core is made of plastic material, suitably adiprene.
At measurements on rock mechanics a well-known deficiency is the fact that the time changes of pressure values that are necessary to determine the stress state and the elasticity modulus of the rock are registered on the base of diagrams that are taken down by regarding only few characteristic values. This causes a deviation mainly in determining the elasticity modulus. In order to eliminate these deviations, a measurement procedure has been developed in accordance with the probe. By the help of this procedure the stress values that are characteristic to the rock wall can be perfectly determined, and the measured parameters can be registered.
The method according to the invention is based upon the fact that if the changes of pressure in the probe or the changes of the probe's volume caused by the pressure of rock are continuously sensed and registered, then the strength characteristics of the rock wall can be determined more precisely than by the presently known methods. This procedure can be carried out by using the invented probe because it can stand its manifold employment without damage in the course of the measurement procedure.
On the other hand the invention enables determining the strength characteristics of rock walls or for measurements on soil mechanics mainly by using the invented probe. In this procedure the probe is placed in a bore-hole that is bored in the rock wall or in the soil on the place of examination, then hydraulic fluid is pressed into the probe by means of a screw pump while the displacement of the piston and the value of pressure are continuously measured, then these values are transformed into electronic signals and fed into an electronic memory unit.
Besides the examinations for rock mechanics, the probe can also advantageously be used in stoping technologies as a breaker e.g. substituting safe blastings, or in gassy, dangerously collapsible places as well as in block breakings e.g. marble mining.
Further details of the invention will be described with reference to the attached drawings, wherein Fig. 1 is the section of the bore-hole probe and Fig. 2 is the connection scheme of the devices applied in the in,anted measurement procedure.
Fig. 1 shows that both ends of a steel core (19) are formed as truncated cones and this shaping results in sealing edges (16). Opposite to these sealing edges (16) the internal conical surface of the locking elements (18) can be found whose bevel angle is suitably greater than the bevel angle formed on the steel core. A flexible plastic jacket (17) is pulled over the superficies of the steel core (19). The flexible jacket (17) has a tubular form, thus only its endings have to be sealed properly after pulling over the steel core (19). The sealin'g edges (16) of the truncated conical surfaces of the steel core (19) and (18) that are pla- the locking elements -ed on the threaded stubs (14) formed on the endings of the steel core can be pressed against each other by means of the locking nuts (155) so that the endings of the flexible jacket (17) are pressed between the sealing edge and the locking el-ement. On one ending of the probe there is an inlet boring shaped in the steel core (19) in order to let the hydraulic fluid be pressed in the probe. This boring is able to lead the fluid into the space between the steel care (19) and the flexible jacket (17), i.e. the pressure of the fluid pressed here tries to remove the flexible jacket (17) from the surface of the steel core (19).
According to the arrangement of Fig. 2, the probe (1) is prestressed by a hand pump (3) till it bears up on the internal surface of the boring. During the actual measurement the squeeze of the hydraulic fluid happens through a tube of high rigidity, e.g. copper tube. The required increase in the fluid pressure can be ensured by a continuous screw pump. The displacement of the piston of the screw displacement pump (2) is measured and is transformed into analogue electronic signal. For this purpose, a sensor (7) is installed on the piston. The screw piston (2) is also provided with an analogue manometer (5) to show the blasting pressure and with a pressure sensor (6) to produce an electronic signal according to the actual pressure value. The electronic signals produced by the two sensors go through amplifiers and an analogue-to-digital converter (8) and are stored in the electronic memory unit (9). The stored signals can be processed by a computer (10). The tube of the probe is also provided with a manometer (13) with removable membrane. The bending of the membrane can be detected by a mechanical displacement sensor. The manometer (13) operates if the probe (1) is left in the hole after boring and only the stress state change of the hole's environment is to be detected. By using the removable membrane, the rigidity of the probe-tube- -manometer system can be modified if different types of membranes are applied. This is necessary because the measured change in fluid pressure shows the stress change in the rock only if the rigidity of the 8 - measurement system is equal to that of the rock.
When the probe is used in blasting rack walls, then bore-holes have to be made in the rock wall on the places of blasting, then the probe has to be placed into the hole and the pressure has to be increased in the system till the rock bursts.
The computer 10 is preferably associated with a VDU screen 11 and a printer 12 for displaying and recording the output data.
In the appended claims reference numbers have been used purely for illustration and expressly not for limitation of the scope of these claims.
Summary of terminology probe screw displacement pump 3. hand pump 4. hydraulic fluid 5. manometer 6. pressure sensor 7. displacement sensor 8. converter 9. electronic memory unit 10. 11. 12. 13. 14. 15. 16. 17. 18. 19.
computer display printer manometer with removable membran threaded stub locking nut sealing edge flexible jacket locking element steel core 1
Claims (5)
1. Hydraulic rock-blasting bore-hole probe for determining strength parameters of rock walls or for blasting rocks or for measurements on soil mechanics that consists of a metal core having an inlet bore and a flexible jacket that covers the surface of the said core and has sealed endings, c h a r a c t e r i z e d in that both ends of the steel core (19) have a tapering shape with truncated cone endings, the core has threaded stubs (14) as continuations, the upper endings of the truncated cones form sealing edges (16), the threaded stubs (14) have locking elements (18) pressed on.the stubs by locking nuts (15), the locking elements (18) fit the sealing edges (16) by their internal tapering surfaces that have greater bevel angle than that of the truncated cone of the said core, and the material of the flexible jacket (17) pulled over the said core (19) is plastic, preferably adiprene.
2. Method for determining strength parameters of rock walls or for measurements on soil mechanics mainly by using the probe of claim 1, wherein the probe is placed in a hole made in the rock wall or in the soil at the place of examination, c h a r a c t e r i z e d i n that hydraulic fluid is pressed into the probe by means of a screw pump while the displacement of the 11 screw piston and the pressure are measured, then these values are transformed into electronic signals and are stored in an electronic memory unit.
3. The method as claimed in claim 2, c h a r a c t e r i z e d i n that a dial indicator is connected to the hydraulic tube going into the probe, then the pressure is increased in the system till the rock blasts, then the probe connected to the dial indicator is removed from the system, and the stress state of the rock wall is determined on the base of the pressure values shown by the dial indicator.
4. A probe according to claim 1 substantially as herein described with reference to and as shown in the accompanying drawings.
5. A method according to claim 2 substantially as herein described with reference to and as shown in the accompanying drawings.
Published 1989 at The Patent Office, State House, 66/71 High Holborn, London WC1R 4TP. Purther copies may be obtained from The Patent Offlee. Wes Branch, St Mary Cray, Orpington, Kent BR5 3RD. Printed by Multiplex techniques ltd, St Mary Cray, Kent, Con- 1/87
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19883823495 DE3823495A1 (en) | 1988-07-12 | 1988-07-11 | HYDRAULIC STONE-DRILLING HOLE HOLE PROBE AND METHOD FOR ITS USE |
| GB8816573A GB2220686A (en) | 1988-07-12 | 1988-07-12 | Hydraulic rock-blasting bore-hole probe and a method for its application |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB8816573A GB2220686A (en) | 1988-07-12 | 1988-07-12 | Hydraulic rock-blasting bore-hole probe and a method for its application |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB8816573D0 GB8816573D0 (en) | 1988-08-17 |
| GB2220686A true GB2220686A (en) | 1990-01-17 |
Family
ID=10640309
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB8816573A Withdrawn GB2220686A (en) | 1988-07-12 | 1988-07-12 | Hydraulic rock-blasting bore-hole probe and a method for its application |
Country Status (2)
| Country | Link |
|---|---|
| DE (1) | DE3823495A1 (en) |
| GB (1) | GB2220686A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5165276A (en) * | 1990-12-07 | 1992-11-24 | Schlumberger Technology Corporation | Downhole measurements using very short fractures |
| US5295393A (en) * | 1991-07-01 | 1994-03-22 | Schlumberger Technology Corporation | Fracturing method and apparatus |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104215510B (en) * | 2014-10-10 | 2016-06-01 | 山东科技大学 | A kind of bored grouting simulation test device |
| CN106405053B (en) * | 2016-10-13 | 2018-12-04 | 中国科学院武汉岩土力学研究所 | A kind of air pressure demolition set that simulation tunnel drilling and blasting method excavates |
-
1988
- 1988-07-11 DE DE19883823495 patent/DE3823495A1/en not_active Withdrawn
- 1988-07-12 GB GB8816573A patent/GB2220686A/en not_active Withdrawn
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5165276A (en) * | 1990-12-07 | 1992-11-24 | Schlumberger Technology Corporation | Downhole measurements using very short fractures |
| US5295393A (en) * | 1991-07-01 | 1994-03-22 | Schlumberger Technology Corporation | Fracturing method and apparatus |
Also Published As
| Publication number | Publication date |
|---|---|
| GB8816573D0 (en) | 1988-08-17 |
| DE3823495A1 (en) | 1990-01-18 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |