CN103698805A - Columnar jointed rock mass unidirectional micro-seismic monitoring sensor layout direction determining method - Google Patents
Columnar jointed rock mass unidirectional micro-seismic monitoring sensor layout direction determining method Download PDFInfo
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- 238000012544 monitoring process Methods 0.000 title claims abstract description 81
- 239000011435 rock Substances 0.000 title claims abstract description 66
- 238000000034 method Methods 0.000 title claims abstract description 15
- 238000012360 testing method Methods 0.000 claims abstract description 34
- 238000009434 installation Methods 0.000 claims description 5
- 238000001514 detection method Methods 0.000 claims description 4
- 230000000694 effects Effects 0.000 abstract description 9
- 230000009286 beneficial effect Effects 0.000 abstract description 3
- 238000005516 engineering process Methods 0.000 abstract description 3
- 239000002002 slurry Substances 0.000 description 4
- 238000009412 basement excavation Methods 0.000 description 3
- 239000004568 cement Substances 0.000 description 3
- 239000002893 slag Substances 0.000 description 3
- 238000013519 translation Methods 0.000 description 3
- 241000124879 Grus leucogeranus Species 0.000 description 2
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- 235000013336 milk Nutrition 0.000 description 2
- 230000035939 shock Effects 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
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Abstract
本发明公开了一种柱状节理岩体单向微震监测传感器布置方向确定方法，本发明的技术方案是：针对横观各向同性的柱状节理岩体，为了单向微震监测传感器能更准确采集到柱状节理破裂时产生的微震动信号，本发明通过声波测试技术分别获取声波在平行和垂直柱状节理岩体柱体轴线方向的波速，将单向微震监测传感器与声波波速大的方向呈一致布置，从而有利于单向微震监测传感器对柱状节理破裂时产生的微震动信号进行采集，提高了柱状节理岩体稳定性微震实时监测预警效果，适用于柱状节理岩体微震监测。
The invention discloses a method for determining the arrangement direction of a one-way microseismic monitoring sensor for a columnar jointed rock mass. For the micro-vibration signal generated when the columnar joint is broken, the present invention obtains the wave velocity of the sound wave in the directions parallel to and perpendicular to the column axis of the columnar joint rock mass through the acoustic wave testing technology, and arranges the one-way microseismic monitoring sensor in the same direction as the direction where the acoustic wave velocity is high. Therefore, it is beneficial for the one-way microseismic monitoring sensor to collect the microseismic signals generated when the columnar joints rupture, which improves the real-time microseismic monitoring and early warning effect of the stability of the columnar joint rock mass, and is suitable for the microseismic monitoring of the columnar joint rock mass.
Description
Technical field
The present invention relates to rock mass On Microseismic Monitoring Technique, more specifically relate to the unidirectional microseismic monitoring sensor arranged direction of a kind of prismatic jointing rock mass and determine method, be applicable to prismatic jointing rock mass micro seismic monitoring.
Background technology
Columnar joint structure is a kind of primary tension fracture structure that is rule or irregular columnar shape being common in slag, is more common in Irish touchstone, and in some power stations of China, (white crane beach, Xi Luodu, copper street) all has exposure.Prismatic jointing ROCK MASS JOINT is very grown, and belongs to the poor rock mass of integrality, and in engineering excavation process, self-stable ability is poor, easily destroys, and workmen and project progress are all existed to larger safety hazard.Take power station, white crane beach is example, has occurred that repeatedly prismatic jointing rock mass falls piece, collapses and Rock-burst in the diversion tunnel having excavated, serious workmen's safety and the project progress of affecting.
Prismatic jointing rock mass can be regarded transverse isotropy body as conventionally, and rock mass is isotropy in perpendicular to its cylinder plane, and other directions are anisotropy.Prismatic jointing rock mass is mainly grown and is parallel to longitudinal joint of its cylinder and perpendicular to the horizontal joint of its cylinder, and the physico-mechanical properties at two groups of joints exists bigger difference, the shock wave producing while causing prismatic jointing to break is also obviously different with the propagation characteristic that is parallel to column axis direction perpendicular to column axis direction.Utilizing unidirectional microseismic monitoring sensor to break signal while gathering to column jointed rock mass, because unidirectional microseismic monitoring sensor has obvious directivity, the arranged direction of unidirectional microseismic monitoring sensor has material impact to the break acquisition capacity of the vibration signal that produces of column jointed rock mass.When the direction of vibration of shock wave is consistent with unidirectional microseismic sensors axis direction, unidirectional microseismic monitoring sensor can better collect shocking waveshape, otherwise what collect is exactly oscillating component.Therefore, while carrying out micro seismic monitoring in the rock mass of prismatic jointing, the vibration signal that appropriate unidirectional microseismic monitoring sensor arranged direction can better receive prismatic jointing rock mass to be produced while breaking, improve prismatic jointing rock stability microseism Monitoring and forecasting system in real-time effect, guarantee workmen's safety and construction speed.At present, the research of this aspect there is not yet pertinent literature report.
Summary of the invention
For above-mentioned existing problems, the object of the present invention is to provide rock mass unidirectional microseismic monitoring sensor arranged direction in a kind of prismatic jointing to determine method, for prismatic jointing rock mass transverse isotropy feature, by the unidirectional microseismic sensors direction of reasonable Arrangement, make unidirectional microseismic monitoring sensor be conducive to gather the microseismic activity signal that prismatic jointing rock mass breaks and produces, thereby improve prismatic jointing rock stability microseism Monitoring and forecasting system in real-time effect, guarantee workmen's safety and construction speed.
To achieve these goals, the technical solution adopted in the present invention is: rock mass unidirectional microseismic monitoring sensor arranged direction in a kind of prismatic jointing is determined method, said method comprising the steps of:
Near the occurrence that a measures column jointed rock mass column axis definite micro seismic monitoring position, in the rock mass of prismatic jointing, be drilled with the first sound wave instrument connection and the second sound wave instrument connection, the first sound wave instrument connection occurrence is parallel with prismatic jointing rock mass column axis occurrence, and the second sound wave instrument connection occurrence is vertical with prismatic jointing rock mass column axis occurrence.
B carries out sonic test by 20cm interval by the translation pointwise of Di Xiang aperture, hole at the bottom of sonic detection transducer is pushed respectively to the first sound wave instrument connection and the second sound wave instrument connection hole, obtains the first sound wave instrument connection and the second sound wave instrument connection different depth place acoustic velocity.All test point values of wave speed after stable to the first sound wave instrument connection and the second sound wave instrument connection acoustic velocity respectively average, and average as this instrument connection acoustic velocity.
C contrasts the first measured sound wave instrument connection and the second sound wave instrument connection acoustic velocity size, determines the occurrence in micro seismic monitoring hole, and the cement bond logging prospect hole occurrence that the occurrence in micro seismic monitoring hole is large with acoustic velocity is consistent.
D is drilled with micro seismic monitoring hole according to definite occurrence in the rock mass of prismatic jointing, with mounting rod by unidirectional microseismic monitoring sensor along the horizontal sliding of micro seismic monitoring hole to pre-installation position, fixing unidirectional microseismic monitoring sensor.
At the bottom of the first described sound wave instrument connection and the second sound wave instrument connection hole, residing position is all over country rock relaxation depth.
The first described sound wave instrument connection and the second sound wave instrument connection acoustic velocity refer to prismatic jointing rock mass protolith acoustic velocity.
The invention has the beneficial effects as follows: for the prismatic jointing rock mass of transverse isotropy, the microseismic activity signal producing in the time of more accurately collecting prismatic jointing and break for unidirectional microseismic monitoring sensor, the present invention obtains respectively sound wave at the velocity of wave of parallel and vertical column jointed rock mass column axis direction by sonic test technology, the unidirectional microseismic monitoring sensor direction large with acoustic velocity is to consistent layout, thereby the microseismic activity signal producing when being conducive to unidirectional microseismic monitoring sensor and being broken in prismatic jointing gathers, improved prismatic jointing rock stability microseism Monitoring and forecasting system in real-time effect.
Accompanying drawing explanation
Fig. 1 is prismatic jointing Rock Tunnel and cement bond logging prospect hole schematic diagram
Fig. 2 is for being parallel to prismatic jointing rock mass cylinder axial direction instrument connection acoustic velocity test result
Fig. 3 is perpendicular to prismatic jointing rock mass cylinder axial direction instrument connection acoustic velocity test result
Fig. 4 is that Rock Tunnel unidirectional microseismic monitoring sensor in prismatic jointing is arranged schematic diagram.
Embodiment
Below in conjunction with accompanying drawing, technical scheme of the present invention is described in further detail.
See accompanying drawing.
Rock mass unidirectional microseismic monitoring sensor arranged direction in prismatic jointing is determined a method, said method comprising the steps of:
A utilizes geologic compass to measure the axis occurrence of column jointed rock mass 2 cylinders near definite micro seismic monitoring position 1, adopts rig to be drilled with the first sound wave instrument connection 301 and the second sound wave instrument connection 302 in prismatic jointing rock mass 2.The first survey cement bond logging prospect hole 301 occurrence are parallel with the 2 column axis occurrence of prismatic jointing rock mass, and the second sound wave instrument connection 302 occurrence are vertical with the 2 column axis occurrence of prismatic jointing rock mass.At the bottom of the first sound wave instrument connection 301 and the second sound wave instrument connection 302 holes, residing position, all over country rock relaxation depth, guarantees that sonic test can obtain prismatic jointing rock mass 2 different directions protolith acoustic velocities.
At the bottom of b pushes respectively the first sound wave instrument connection 301 and the second sound wave instrument connection 302 holes by sonic detection transducer, by 20cm interval, by the translation pointwise of Di Xiang aperture, hole, carry out sonic test, obtain the first sound wave instrument connection 301 and the second sound wave instrument connection 302 different depth place acoustic velocities with hole depth change curve.All test point values of wave speed after stable to the first sound wave instrument connection 301 and the second sound wave instrument connection 302 acoustic velocities respectively average, and average as this instrument connection acoustic velocity.
C contrasts the first measured sound wave instrument connection 301 and the second sound wave instrument connection 302 acoustic velocity sizes, determine the occurrence in micro seismic monitoring hole 5, when the first sound wave instrument connection 301 acoustic velocities are greater than the second sound wave instrument connection 302 acoustic velocity, the occurrence in micro seismic monitoring hole 5 is consistent with the first sound wave instrument connection 301 occurrence.Otherwise the occurrence in micro seismic monitoring hole 5 is consistent with the second sound wave instrument connection 302 occurrence.
D adopts rig in prismatic jointing rock mass 2, to be drilled with micro seismic monitoring hole 5 according to definite occurrence, micro seismic monitoring hole 5 degree of depth surpass the pre-burial place 20cm of unidirectional microseismic monitoring sensor 4, prevent that in hole, falling slag muck stops up the space that unidirectional microseismic monitoring sensor 4 is installed in 5 bottoms, micro seismic monitoring hole.Guarantee micro seismic monitoring hole 5 quality, without obvious twisted phenomenon.With mounting rod by unidirectional microseismic monitoring sensor 4 along 5 horizontal slidings of micro seismic monitoring hole to pre-installation position, bonding is parallel with micro seismic monitoring hole 5 to microseismic monitoring sensor 4 axis directions.In micro seismic monitoring hole 5, be in the milk, make slurries be full of micro seismic monitoring hole 5, slurries solidify rear unidirectional microseismic monitoring sensor 4 just with 2 fixed coupling of prismatic jointing rock mass.
Specific embodiment:
Certain prismatic jointing Rock Tunnel excavation, prismatic jointing cylinder is hexagon, and cylinder is monolateral to be about as 0.1m, and height is about 0.5 ~ 0.8m, and country rock relaxation depth is within the scope of 5m.Use unidirectional microseismic monitoring sensor to carry out real-time monitoring of stability to tunnel excavation, unidirectional microseismic monitoring sensor arranged direction determines that method is described in detail as follows.
A is in definite 1(tunnel, micro seismic monitoring position) near utilize geologic compass to measure the axis occurrence of column jointed rock mass 2 cylinders, occurrence is 50 ° of 36 ° of ∠, adopt rig from prismatic jointing Rock Tunnel 1 abutment wall to the first sound wave instrument connection 301 and the second sound wave instrument connection 302 that to be drilled with two diameters in prismatic jointing rock mass 2 be 76mm.The first sound wave instrument connection 301 occurrence are 50 ° of 36 ° of ∠, parallel with the 2 column axis occurrence of prismatic jointing rock mass, and the second sound wave instrument connection 302 occurrence are 40 ° of 216 ° of ∠, vertical with the 2 column axis occurrence of prismatic jointing rock mass.The first sound wave instrument connection 301 and second sound wave instrument connection 302 degree of depth are 20m, and at the bottom of hole, residing position surpasses country rock relaxation depth, guarantee that sonic test can obtain prismatic jointing rock mass 2 different directions protolith acoustic velocities.
B adopts RSM-SY5 intelligence sonic apparatus to carry out sonic test to the first sound wave instrument connection 301 and the second sound wave instrument connection 302, at the bottom of the sonic detection transducer of RSM-SY5 intelligence sonic apparatus is pushed respectively to the first sound wave instrument connection 301 and the second sound wave instrument connection 302 holes, by 20cm interval, by the translation pointwise of Di Xiang aperture, hole, carry out sonic test, obtain the first sound wave instrument connection 301 and the second sound wave instrument connection 302 different depth place acoustic velocities with hole depth change curve, as shown in Figures 2 and 3.After the first sound wave instrument connection 301 hole depths reach 4.3m, acoustic velocity is stabilized in 4800m/s left and right, the all test point values of wave speed that the first sound wave instrument connection 301 hole depths are not less than to 4.3m average, obtaining mean value is 4838.4m/s, as the first sound wave instrument connection 301 acoustic velocities (seeing accompanying drawing 2).After the second sound wave instrument connection 302 hole depths reach 4m, acoustic velocity is stabilized in 5400m/s left and right, the all test point values of wave speed that the second sound wave instrument connection 302 hole depths are not less than to 4m average, obtaining mean value is 5381.5m/s, as the second sound wave instrument connection 302 acoustic velocities (seeing accompanying drawing 3).
C contrasts the first measured sound wave instrument connection 301 and the second sound wave instrument connection 302 acoustic velocity sizes, by known the second sound wave instrument connection 302 acoustic velocities of sonic test result, be greater than the first sound wave instrument connection 301 acoustic velocities, the vibration wave producing when prismatic jointing rock mass 2 breaks propagates in the second sound wave instrument connection 302 directions the advantage that exists, therefore, in the second sound wave instrument connection 302 directions, be beneficial to unidirectional microseismic monitoring sensor 4 collection signals, the occurrence in micro seismic monitoring hole 5 is consistent with the second sound wave instrument connection 302 occurrence.
D adopts rig to be drilled with micro seismic monitoring hole 5 according to the direction consistent with the second sound wave instrument connection 302 occurrence, as shown in Figure 4.Micro seismic monitoring hole 5 degree of depth surpass the pre-burial place 20cm of unidirectional microseismic monitoring sensor 4, prevent that in hole, falling slag muck stops up the space that unidirectional microseismic monitoring sensor 4 is installed in 5 bottoms, micro seismic monitoring hole.Micro seismic monitoring hole 5 is without obvious twisted phenomenon, and quality is good.With mounting rod by unidirectional microseismic monitoring sensor 4 along 5 horizontal slidings of micro seismic monitoring hole to pre-installation position, bonding is parallel with micro seismic monitoring hole 5 to microseismic monitoring sensor 4 axis directions.In micro seismic monitoring hole 5, be in the milk, make slurries be full of micro seismic monitoring hole 5, slurries solidify rear unidirectional microseismic monitoring sensor 4 just with 2 fixed coupling of prismatic jointing rock mass.
The vibration wave producing when prismatic jointing rock mass 2 breaks propagates in the second sound wave instrument connection 302 directions the advantage that exists, unidirectional microseismic monitoring sensor 4 and the consistent cloth postpone of the second sound wave instrument connection 302 direction, the microseismic activity signal producing while being conducive to column jointed rock mass 2 to be broken gathers, thereby improves prismatic jointing rock stability microseism Monitoring and forecasting system in real-time effect.
Above example is only unrestricted in order to technical scheme of the present invention to be described, those of ordinary skill in the art is to be understood that, technical scheme of the present invention is modified or is replaced on an equal basis, and does not depart from the spirit and scope of technical solution of the present invention, all should be encompassed in claim scope of the present invention.
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104236489A (en) * | 2014-09-18 | 2014-12-24 | 中国电建集团华东勘测设计研究院有限公司 | Method for judging anisotropic relative relaxation thicknesses of surrounding rock of chamber of columnar jointing basalt |
| CN107065005A (en) * | 2017-06-14 | 2017-08-18 | 四川大学 | A kind of microseism test system |
| CN107102352A (en) * | 2017-06-14 | 2017-08-29 | 四川大学 | A kind of reusable Microseismic monitoring system of microseismic sensors |
| CN107290778A (en) * | 2017-06-14 | 2017-10-24 | 四川大学 | A kind of mechanical couplings formula Microseismic monitoring system |
| CN108919348A (en) * | 2018-09-19 | 2018-11-30 | 东北大学 | A kind of crack rock intelligence slip casting TT&C system and implementation method |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102053257A (en) * | 2009-11-02 | 2011-05-11 | 煤矿瓦斯治理国家工程研究中心 | Sensor fixing device, mounting device and mounting method |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102053257A (en) * | 2009-11-02 | 2011-05-11 | 煤矿瓦斯治理国家工程研究中心 | Sensor fixing device, mounting device and mounting method |
Non-Patent Citations (2)
| Title |
|---|
| ZHI-GANG SHAN: ""Loading-unloading test analysis of anisotropic columnar jointed basalts"", 《JOURNAL OF ZHEJIANG UNIVERSITY-SCIENCE A (APPLIED PHYSICS & ENGINEERING)》 * |
| 江权等: ""柱状节理玄武岩各向异性的调查与试验研究"", 《岩石力学与工程学报》 * |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104236489A (en) * | 2014-09-18 | 2014-12-24 | 中国电建集团华东勘测设计研究院有限公司 | Method for judging anisotropic relative relaxation thicknesses of surrounding rock of chamber of columnar jointing basalt |
| CN104236489B (en) * | 2014-09-18 | 2017-05-31 | 中国电建集团华东勘测设计研究院有限公司 | Prismatical joint basalt surrounding rock of chamber anisotropy relative relaxation degree evaluation method |
| CN107065005A (en) * | 2017-06-14 | 2017-08-18 | 四川大学 | A kind of microseism test system |
| CN107102352A (en) * | 2017-06-14 | 2017-08-29 | 四川大学 | A kind of reusable Microseismic monitoring system of microseismic sensors |
| CN107290778A (en) * | 2017-06-14 | 2017-10-24 | 四川大学 | A kind of mechanical couplings formula Microseismic monitoring system |
| CN107102352B (en) * | 2017-06-14 | 2023-03-28 | 四川大学 | Microseism monitoring system with reusable microseism sensor |
| CN107065005B (en) * | 2017-06-14 | 2023-05-09 | 四川大学 | Microseism test system |
| CN108919348A (en) * | 2018-09-19 | 2018-11-30 | 东北大学 | A kind of crack rock intelligence slip casting TT&C system and implementation method |
| CN108919348B (en) * | 2018-09-19 | 2023-06-27 | 东北大学 | An intelligent grouting measurement and control system for cracked rock mass and its implementation method |
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Application publication date: 20140402 |