A kind of contactless rock pressure [in mine observation and evaluation method
Technical field
The present invention relates to the technology that a kind of electromagnetic radiation information that produces by contactless monitoring stand under load coal and rock comes the relative stress state of monitoring and evaluation mine excavation space or tunnel surrounding, the technical field that belongs to the rock pressure [in mine monitoring and estimate.
Background technology
Carry out in the mining process the mankind, recovery activity has been destroyed initial stress equilibrium state, causes to adopt space terrestrial stress redistribution on every side.Around stope and mining roadway, because the effect of surrouding rock stress impels country rock to deform, destroy and move, roof collapse occurs and press, roof and floor shifts near, support stand under load and the ore deposit such as contract, lose down and press and manifest, and dynamic phenomenons such as coal and gas are given prominence to, gushing water, rock burst also may occur.
Therefore, monitoring and distribution and the Changing Pattern of estimating the surrouding rock stress state are the main contents that observation is pressed in the ore deposit, are the foundations that solves key technical problems such as coal body safe working on ore deposit, the tunnel pressure-controlled, mining sequence design, tunnel rational position selection and maintenance, rock burst and the coal that are subjected to mining influence and gas outbursts Prediction and control, the piestic water.
At present, the sensor that detects stress in the engineering is of a great variety, the scope of application is extensive, but rare to the instrument of coal petrography tunnel surrouding rock stress status monitoring in the mining, and especially noncontact monitoring and the regional evaluation to the regional stress state of coal and rock under the coal mine almost is blank.
In engineering practice, the surrouding rock stress state monitoring method mainly contains supporting resistance method, pressure gauge (box) method, strain gauge method (or deformation method) etc.Its observed parameter mainly contains: coal-face and tunnel pillar (frame) working resistance and extra-stress, the relative amount of shifting near of roof and floor and roadway surrounding rock surface displacement, the inner initial stress of rock mass and extra-stress, country rock deep displacement etc.Before the observation of applying pressure meter (box) method, all will demarcate dynamometer, because of the variation of working environment, its operating characteristic changes probably in the use at every turn; The dynamometer that uses also must satisfy the Rigidity Matching condition.Strain gauge method is measured relevant with the stress-strain physical characteristics of coal (rock) body, and deformation parameter is difficult to be determined, determines for more being difficult to resolve than cherry coal (rock) layer.Said method all is the contact monitoring method, and contact monitoring surrouding rock stress state is generally a contact monitoring, be subjected to the coal and rock structure, stress distribution is inhomogeneous and supporting just load influence bigger, how to select representational measuring point, how to guarantee that sensor contacts with the good of coal petrography, this all is a difficult problem that the contact monitoring faces, and also can considerable influence be arranged to monitoring result simultaneously.Therefore, at the scene, contactless, regional stress trajectory and evaluation have more practical significance.
In the table 1, patent 1 and patent 2 are monitored the program complexity of surrouding rock stress state at the coal mine stress test; Patent 3 is used for the relative measurement of terrestrial stress; The three is the contact test, boring deformation and corresponding conversion of surveying between parameter in coal (rock) body, be subjected to structure, material, the processing technology of sensor, the restriction of surface of contact machining precision aspect, be difficult to avoid temperature and pressure interference in electromagnetism, the hole, thereby poor stability, particularly under coal mine, coal and rock is more open around the digging space, and good contact is difficulty comparatively.Above-mentioned patent does not all realize non-contact detection, and test preliminary work is loaded down with trivial details, requires high.
The instrument of table 1 stress test
In the last few years, coal petrography electromagnetic radiation characteristic and applied research aspect thereof had obtained bigger progress.The ELECTROMAGNETIC RADIATION SIGNATURE that patent of invention " method and the device of prediction gassiness coal petrography concrete disaster; (ZL98111185.8) " produces during by the deformation fracture of noncontact monitoring stand under load coal and rock and (several minutes) Changing Pattern in short-term thereof, the outstanding danger with coal rock dynamic disaster such as rock burst of forecast coal and gas, its reflection be the instantaneous state in a certain stage in the coal rock dynamic disaster evolutionary process, do not realize real uninterrupted continuously monitoring and forecast, can not share the resource of KJ coal mine safety monitoring system.
Utility model patent " coal rock dynamic disaster electromagnetic radiation monitoring device; the patent No. is ZL01272808.X " can carry out continuous monitoring early warning coal rock dynamic disaster danger under the situation of external power supply, but can not connect with KJ series coal mine safety monitoring system, can not share the power supply and the transmission channel of safety monitoring system, realize that remote monitoring needs independent wiring and independent power supply, and a little less than forecasting that function.
Patent of invention " real time monitoring forecasting device of coal rock dynamic disaster and forecasting procedure, the patent No. are ZL200410065793.1 ", its main application is that coal rock dynamic disaster is carried out continuous real-time monitoring and early warning.
Summary of the invention
Technical matters: the purpose of this invention is to provide a kind of contactless rock pressure [in mine observation and evaluation method, the ELECTROMAGNETIC RADIATION SIGNATURE that the main monitoring index of this method produces for the stand under load coal and rock, can carry out noncontact, regional test to the relative stress state of mine or tunnel surrounding by this method, but the regional regularity of distribution and the dynamic rule of counter stress state are estimated, and determine the stress abnormality zone.The advantage of this observation procedure is installation and easy to operate, quick, and less to producing influence, expense is low.
Technical scheme: the stand under load coal and rock can produce electromagnetic radiation and be proved by our a large amount of experimental observation and theoretical analysis, the deformation fracture process of electromagnetic radiation intensity and load and coal body is proportionate, that is: load is big more, and electromagnetic radiation intensity (EMR) is strong more, and vice versa.Therefore, electromagnetic radiation intensity can reflect the stress state of coal and rock preferably.
Contactless rock pressure [in mine observation procedure of the present invention is:
A. at first will select the zone that need monitor, then 1~n measuring point be arranged, the measuring point arrangement pitch is L
1=1~10 meters;
B. the effective receive direction of directive reception electromagnetic antenna is aimed at measuring point, make the outside surface that is axially perpendicular to measuring point of antenna, and fix antenna, the distance of antenna and tested coal petrography wall is L
2=0.1~1 meter, its principle of determining is that monitored measuring point zone just is included in the 60 degree opening directions of antenna;
C. each measuring point monitoring time is T=0.5~3min, and monitor is gathered the electromagnetic radiation intensity data in real time in the test process, and electromagnetic radiation intensity maximal value or the mean value of adding up p.s. calculate the mean value E in the T time then
iAs the final testing result of i measuring point, as the foundation of estimating this measuring point pressure size and storage;
D. after i measuring point finished in test, move to next measuring point i+1 and proceed test, obtain E
I+1, finish until all measuring point tests.
The evaluation method of contactless rock pressure [in mine observation is:
A. the index of rock pressure [in mine evaluation adopts the mean value E of coal petrography electromagnetic radiation intensity
i, certain measuring point electromagnetic radiation intensity is big more, shows that then the ore deposit of this measuring point is pressed big more;
B. in computing machine, calculate all measuring point electromagnetic radiation intensity E
iMean value
Contrast index as rock pressure [in mine;
C. the electromagnetic radiation test result E of different measuring points in this evaluation region
iShow in the drawings, horizontal ordinate is measuring point numbering or point position, and ordinate is the electromagnetic radiation intensity E of measuring point
i, also mark the horizontal line of E=Eavg in the drawings;
D. the direct regularity of distribution of different measuring points rock pressure [in mine as can be seen from figure, the electromagnetic radiation intensity E of measuring point
iBig more, show that this rock pressure [in mine is big more;
E. when survey electromagnetic radiation intensity during greater than Eavg, this measuring point is be evaluated as high stress point, the electromagnetic radiation intensity value of continuous two the above measuring points of certain regional area illustrates that near the ore deposit pressure this measuring point is bigger, if all greater than Eavg, should the zone be a high stress areas then;
F. present rapid increase more than 1 times or sharply reduce zone more than 50% for the electromagnetic radiation intensity of adjacent two or more measuring points, be evaluated as the high stress gradients district;
For the region of high stress or high stress gradients district, should make prompting, this generally is the district occurred frequently and the comparatively difficult zone of supporting of coal rock dynamic disaster, can be used as the foundation of engineering decisions such as supporting design, disaster prevention.
The present invention can realize to the surrouding rock stress state carry out effectively, noncontact, orientation, regional monitoring and estimate, filled up the blank of contactless, regional monitoring and evaluation of the stress state of down-hole, mine coal and rock.
Beneficial effect: the contactless rock pressure [in mine observation technology based on the coal petrography electromagnetic radiation principle has adopted contactless receiving antenna, and test and evaluation index are electromagnetic radiation intensity.Realized real contactless, directed and regional monitoring, reflection be the general status of surrouding rock stress state in the scope of monitored area, more sensitive to the region of high stress, high stress gradients district or the reflection of heavily stressed behaviour area.The present invention compares with existing coal and rock stress test technology: more effective quick, significantly reduced workload, substantially be not subjected to external interference such as artificial (for electromagnetic interference (EMI) such as down-hole electromechanical equipments, then by taking shielding or directive reception technology to get rid of), what test result reflected is the integrated stress response (regional area stress) of measuring point regional area coal and rock, be particularly suitable for forward probe in the Coal Production process and the forward probe of tectonic structure or stress abnormality district (or area of stress concentration), also can be widely used in coal mining, building, water conservancy, road, the tunnel, underground works etc.
Description of drawings
Fig. 1 is the contactless rock pressure [in mine observation of a present invention process flow diagram.
Fig. 2 is that the contactless rock pressure [in mine of the present invention is estimated process flow diagram.
Fig. 3 is that the contactless rock pressure [in mine observation of the present invention measuring point is arranged synoptic diagram.
Fig. 4 be the present invention in Chongqing towards tunnel, Tianmen arch angular measurement line upward pressure observed result example.Observed result manifests consistent with actual pressure.
Fig. 5 be the present invention at Xuzhou Zhang Ji coal mining workplace electromagnetic radiation intensity test result and hydraulic support pressure P comparison diagram, show that the ore deposit presses observed result consistent with the actual stress distribution.
Fig. 6 is that the present invention helped the ore deposit to press observation and evaluation result example 23 days 250205 Dec in 2006 in Huating colliery, Gansu outside the workplace haulage gate.Observation and evaluation result are consistent with actual conditions.
Embodiment
Contactless ore deposit presses the process flow diagram of observation to see shown in Figure 1.Before adopting movable type, contactless observation ore deposit to press, at first to select the zone that need monitor, as observation and evaluation region, then measuring point is arranged (1~n measuring point) such as the transportation lane of selecting certain coal face, the measuring point arrangement pitch is L
1(scope is generally 1~10 meter).During monitoring, the effective receive direction of directive reception electromagnetic antenna be aimed at measuring point, make the outside surface that is axially perpendicular to measuring point of antenna, and fix antenna.The distance of antenna and tested coal petrography wall is L
2(scope is 0.1~1 meter), its principle of determining are that monitored measuring point zone just is included in the 60 degree opening directions of antenna, as shown in Figure 4.Each measuring point observation time is that (scope is 0.5~3min to T, generally speaking, each measuring point test 2 minutes), monitor is gathered the electromagnetic radiation intensity data automatically, in real time in the test process, electromagnetic radiation intensity maximal value (or the mean value of real-time statistics p.s., the general maximal value of calculating), after image data is finished, the instant mean value E that calculates automatically in the T time of monitor
iAs the final testing result of i measuring point,, store automatically and show by monitor as the foundation of estimating this measuring point pressure size.After i measuring point finished in test, move to next measuring point i+1 and proceed test, obtain E
I+1After all measuring point tests are finished, take monitor to ground, test result data is imported computing machine.
The index of rock pressure [in mine evaluation is the mean value E of coal petrography electromagnetic radiation intensity
i, the test result that is based on the coal petrography electromagnetic radiation can reflect what rock pressure [in mine carried out in proportion, certain measuring point electromagnetic radiation intensity is big more, shows that then the ore deposit of this measuring point is pressed big more.At first in computing machine, calculate all measuring point electromagnetic radiation intensity E
iMean value
Contrast index as rock pressure [in mine; The electromagnetic radiation test result E of different measuring points in this evaluation region
iShow in evaluation map, horizontal ordinate is measuring point numbering or point position, and ordinate is the electromagnetic radiation intensity E of measuring point
i, also mark the horizontal line of E=Eavg in the drawings; The direct regularity of distribution of different measuring points rock pressure [in mine as can be seen from figure, the electromagnetic radiation intensity E of measuring point
iBig more, show that this rock pressure [in mine is big more; When survey electromagnetic radiation intensity during greater than Eavg, this measuring point is be evaluated as high stress point, illustrate near this measuring point ore deposit press bigger, if the electromagnetic radiation intensity value of continuous two the above measuring points of certain regional area all greater than Eavg, should the zone be a high stress areas then; Present rapid increase more than 1 times or sharply reduce zone more than 50% for the electromagnetic radiation intensity of adjacent two or more measuring points, be evaluated as the high stress gradients district.
For the region of high stress or high stress gradients district, should make prompting, this generally is the district occurred frequently and the comparatively difficult zone of supporting of coal rock dynamic disaster, can be used as the foundation of engineering decisions such as supporting design, disaster prevention.
Fig. 3 is that the contactless rock pressure [in mine observation of the present invention measuring point is arranged synoptic diagram.In the tunnel or workplace, the measuring point spacing requires to can be 1~10 meter according to observation or evaluation precision, and the measuring point spacing is more little, and observation and evaluation precision are high more.Generally for fixing workplace or tunnel, the measuring point spacing is fixed.Each measuring point test 0.5~3 minute after a measuring point test is finished, moves to next measuring point and observes.
Fig. 4 is that the contactless rock pressure [in mine observation instrument of the present invention is arranged synoptic diagram.As seen from the figure, the effective monitoring scope of accepting antenna is for being the center of circle with antenna one end, and radius is 7~22m, and the taper area at 60 ° of angles, observed result are the whole synthesis stress of coal and rock in this scope.
Fig. 5 be adopt the technology of the present invention in Chongqing electromagnetic radiation and the pressure observation result on tunnel, the Tianmen arch angular measurement line.The LA-A` survey line is positioned at Zuo Dong right side Gong Jiao, 2.0m at the bottom of the hole, K4+846.5m~K4+948.5m.The measuring point spacing is 1m, day line-spacing inner surface of tunnel 0.5m, and opening is towards the inner surface of tunnel normal orientation.Each measuring point test 2 minutes is averaged as this test result.What measured value reflected is the overall radiation of electromagnetic radiation source in 60 ° of direction zones.On the vertical survey line of LA-A`, electromagnetic radiation intensity is higher near K4+916.5m, K4+901.5m and the K4+884.5m, shows residing stress state than higher, and this and tunnel upper clump of piles stress stacked tape match.
Fig. 6 is that the present invention is at Xuzhou Zhang Ji coal mining workplace electromagnetic radiation intensity test result and hydraulic support pressure P comparison diagram.The measuring point spacing is 4 supports (6m), each measuring point test 2 minutes, day line-spacing rib 0.5m.As can be seen from Figure, electromagnetic radiation intensity and face timbering resistance (hydraulic support pressure) variation tendency is roughly the same, has correspondence preferably.
Fig. 7 is that the present invention helped the ore deposit to press observation and evaluation result example 23 days 250205 Dec in 2006 in Huating colliery, Gansu outside the workplace haulage gate.The measuring point spacing is 10m, and each measuring point test duration is 2 minutes, and electromagnetic antenna is 0.5m apart from rib.As can be seen, being the region of high stress 46.5m~96.5m between outward at haulage gate from workplace from the figure, is the high stress gradients district between 36.5m~56.5m, between 66.5m~86.5m and between 96.5m~106.5m.