A kind of method measuring wall rock loosening ring based on distributed resistance foil gauge
Technical field
The invention belongs to ore deposit pressure technical field of measurement and test, relate to a kind of method measuring wall rock loosening ring based on distributed resistance foil gauge.
Background technology
Destroy initial stress equilibrium state after roadway excavation, cause stress to redistribute, along with the appearance of stress concentration phenomenon.After concentrated stress is greater than the intensity of country rock, the rock failure mechanism of rock of country rock generation different levels is also progressively expanded to depth by periphery, forms the relaxation zone that a damage fragmented rock body is formed.The physical state of relaxation zone shows as the break increase of seam and the reduction of rock mass stress level, its size reflects the coefficient result of the factor such as surrouding rock stress, rock strength, it is the important parameter analyzed adjoining rock stability, determine support pattern, for reasonably determining that supporting parameter and construction technology have great importance, can as the important evidence of the engineering decision such as design of its support, disaster prevention.
Relaxation zone test is exactly new destruction crack and distribution range thereof after lane is opened in test, having newly break seam and the interface location that stitches of not breaking to be exactly the border of relaxation zone in country rock.Conventional at present have geology thunder method probe method, seismic wave method, osmosis, sonic method, multipoint displacement meter to measure the borehole camera method of method and advanced person to the assay method of wall rock loosening ring.
Geologic radar detection method is a kind of novel non-damaged Detection Techniques, and can adapt to other country rock of different intensity scale, precision, efficiency, resolution are high, but use the expensive of this method, and the method for test is complicated, and the factor of environmental interference is many; The test philosophy of seismic wave method is the then matched curve directly utilizing total ripple, carries out rock stratum velocity contrast and judgement, and the scope of test is large, and data are reliable, but the instrument used is more expensive, the installation difficulty of Probe arrangement and instrument; The principle of osmosis test is simple, and when utilizing rock mass to have a more crack growth and development, permeability becomes large, but the rock stratum to soft rock and water-swellable, difficulty of test is large, and workload is large; Need water filling to be coupled during sonic method test, poor anti jamming capability, when country rock is damaged, when the velocity of wave difference of broken rock velocity of wave and water is little, can not significantly judge relaxation zone scope; Multipoint displacement meter measurement ratio juris is the emergence and development due to relaxation zone implosion seam, the deflection that bulking deformation does not loosen country rock compared with the degree of depth wants large, the advantage of this method is that test data is reliable, simple to operate, but the workload of observation is large, and the precision of test is lower, and monitoring time is long, for the country rock that deflection is little, be difficult to observation; Borehole camera method is applicable to the good rock mass of lithology, containing much information of gained, and test result precision is high, but expensive equipment, execute-in-place is complicated.
In Specific construction process at the scene, said method is measured wall rock loosening ring and mostly be there is complicated operation, the problem that testing expense is high, workload is large.For overcoming appeal problem, invent a kind of completely newly, stability high, fast, economical, distributed resistance foil gauge easy and simple to handle measure the design of its support of relaxation zone method to country rock of country rock, parameter is determined, construction technology etc. has great importance.
Summary of the invention
The object of this invention is to provide a kind of method measuring wall rock loosening ring based on distributed resistance foil gauge, also be a kind of contact method of testing, the distribution range of relaxation zone is analyzed by the strain of strain gage testing diverse location place coal and rock, the method is easy to operate, fast, economical, highly sensitive, measurement result are easy to data processing, is easy to on-the-spot enforcement.
In order to solve the problems of the technologies described above, the present invention adopts following technical scheme:
Measure a method for wall rock loosening ring based on distributed resistance foil gauge, comprise the following steps:
Step 1, rule of thumb formula estimate the scope of test position relaxation zone, again according to the scope estimating the relaxation zone that result provides, select suitable long pvc pipe, make processing testing element, the tube surfaces that resistance strain gage spacing pastes pvc pipe is fixed, stickup direction is consistent, and is numbered each resistance strain gage;
The strain value of step 2, test country rock position:
(21) selected test roadway surrounding rock position and direction,
(22) construction drill, the degree of depth of boring and the length of testing element adapt,
(23) testing element is placed in boring, being directed upwardly of resistance strain gage, injection hole sealing, testing element is coupled with country rock;
(24) debugging strainmeter, being electrically connected by the resistance strain gage being numbered 1 by connecting wire with strainmeter, measurement is numbered the strain value ε of the country rock position corresponding to resistance strain gage of 1
1;
(25) will be numbered 2,3 ..., n resistance strain gage, according to the method for testing of step (24), record and be numbered 2,3 ..., n the strain value ε of country rock position corresponding to resistance strain gage
2..., ε
n-1, ε
n, record stores strain value data;
Step 3, judge the scope of country rock position relaxation zone: according to the test result of step 3, draw out the relation curve of country rock position and strain value ε, by distribution characteristics and the variance analysis of the strain value at the inner diverse location place of country rock, judge the scope of country rock position relaxation zone.
As the further optimization of such scheme, the tube surfaces that described resistance strain gage pastes pvc pipe according to the distance that spacing is 3 ~ 5cm is fixed.
As the further optimization of such scheme, in step 3, judge that the standard of the scope of country rock position relaxation zone is: the country rock between strain value peak to drill hole is within the scope of relaxation zone.
As the further optimization of such scheme, described testing element comprises pvc pipe (1), this pvc pipe (1) is provided with some resistance strain gages (2) along pipe shaft length direction spacing, described resistance strain gage (2) is pasted and fixed on pvc pipe (1), described pvc pipe (1) is provided with some circular holes along pipe shaft length direction spacing, each resistance strain gage (2) limit is equipped with a circular hole (3), each resistance strain gage (2) is electrically connected with one end of a wire (4), described wire (4) is through corresponding circular hole (3), be drawn out to the outside of pvc pipe (1).
Compared with the prior art, a kind of beneficial effect measuring the method for wall rock loosening ring based on distributed resistance foil gauge of the present invention is embodied in:
1, a kind of method measuring wall rock loosening ring based on distributed resistance foil gauge of the present invention, resistor straining testing technique is adopted to measure wall rock loosening ring scope, it is a kind of method of test relaxation zone newly, by measuring the strain value of different surrounding rock degree of depth country rock, obtain tunnel-surrounding country rock Strain Distribution feature, real reflection roadway surrounding rock waits the Changing Pattern of mining influence strain by excavation, opening relationships curve, the scope of relaxation zone can be judged fast, highly sensitive, precision is high, measurement result is easy to data processing.
2, compared with existing Measure Technology for Loose Circle of Crush, a kind of method measuring wall rock loosening ring based on distributed resistance foil gauge of the present invention, testing cost is cheap and greatly reduce workload, the result precision measured is high, be easy to the advantages such as construction at the scene, can be widely used in the test of the wall rock loosening ring such as tunnel, underground works.
Accompanying drawing explanation
Fig. 1 is a kind of schematic flow sheet measuring the method for wall rock loosening ring based on distributed resistance foil gauge of the present invention.
Fig. 2 is the vertical view of testing element of the present invention.
Fig. 3 is the schematic diagram of application testing element test wall rock loosening ring construction.
Fig. 4 is the country rock degree of depth of the preferred embodiment of the present invention and the changing trend diagram of strain value.
Implication is marked as follows: pvc pipe 1, resistance strain gage 2, circular hole 3, wire 4, tunnel 5, boring 6, testing element 7, strainmeter 8 in figure.
Embodiment
Elaborate to embodiments of the invention below, the present embodiment is implemented under premised on technical solution of the present invention, give detailed embodiment and concrete operating process, but protection scope of the present invention is not limited to following embodiment.
A kind of monitoring index measuring the method for wall rock loosening ring based on distributed resistance foil gauge of the present invention is the strain value at country rock diverse location place, the resistance strain gage going out to be pasted onto diverse location place on pvc pipe body by strain-ga(u)ge measurement, by the strain variation after the mining influences such as excavation, determines the scope of relaxation zone.
A large amount of test observations and theoretical analysis show, relaxation zone is in rupture zone, and macro manifestations microfissure increases, and distortion increases, deformation modulus reduces.Be in the strain gage testing country rock strain value out within the scope of relaxation zone, large relative to plastic zone, elastic region and initial stress area, according to the feature of this sudden change of strain, the scope of relaxation zone can be judged.Judge that the standard of the scope of country rock position relaxation zone is: the country rock between strain value peak to drill hole is within the scope of relaxation zone.
Measure a method for wall rock loosening ring based on distributed resistance foil gauge, be a kind of schematic flow sheet measuring the method for wall rock loosening ring based on distributed resistance foil gauge of the present invention see Fig. 1, Fig. 1, comprise the following steps:
Step 101, rule of thumb formula estimate the scope of test position relaxation zone, then according to estimating the scope of the relaxation zone that result provides, selecting suitable long pvc pipe to make and processing testing element:
The tube surfaces that resistance strain gage spacing pastes pvc pipe is fixed, pastes direction and be consistent, and each resistance strain gage is numbered;
See Fig. 2, testing element comprises pvc pipe 1, and this pvc pipe 1 is provided with some resistance strain gages 2 along pipe shaft length direction spacing, and this resistance strain gage 2 is pasted and fixed on pvc pipe 1.This pvc pipe 1 is provided with some circular holes along pipe shaft length direction spacing, and each resistance strain gage 2 limit is equipped with a circular hole 3, and one end of each resistance strain gage 2 and a wire 4 is electrically connected, and this wire 4, through corresponding circular hole 3, is drawn out to the outside of pvc pipe 1.
In this preferred embodiment, on the pvc pipe that the scope of relaxation zone provided with estimation result adapts, spacing is provided with n resistance strain gage 2, and resistance strain gage 2 is arranged on pvc pipe body according to the spacing of L1=L/n=3 ~ 5cm, and the stickup orientation of resistance strain gage 2 is consistent, resistance strain gage 2 is numbered successively, number consecutively be 1#, 2# ..., i#≤n).
Step 102, testing element is utilized to test the strain value of different surrounding rock position:
(21) selected test roadway surrounding rock position and direction;
(22) construction drill, the degree of depth of boring and the length of testing element adapt;
Use air drill or hydrodrill to roadway surrounding rock interior construction boring, the diameter of boring is 42-45mm, and the degree of depth of boring and the length of testing element adapt, and after drilling construction, exit drilling rod.See the schematic diagram that Fig. 3, Fig. 3 are the constructions of application testing element test wall rock loosening ring.Selected tunnel 5, construction drill, makes the length of the degree of depth of boring 6 and testing element 7 adapt.
(23) testing element 7 is placed in boring 6, being directed upwardly of resistance strain gage 2, injection hole sealing, testing element is coupled with country rock;
By the testing element 7 processed, the pvc pipe namely with resistance strain gage is positioned in boring, and being directed upwardly of resistance strain gage carries out slip casting to boring, the real boring of envelope.After sealing of hole completes, stablize 5 ~ 10d, after making testing element and country rock carry out efficient coupling, start to test.See the schematic diagram that Fig. 3, Fig. 3 are the constructions of application testing element test wall rock loosening ring.In stationary phase, protect and draw the wire 4 of testing element 7 outside, preventing from making moist etc. causes wire 4 to damage.
(24) debug strainmeter, be electrically connected by the resistance strain gage being numbered 1# by wire and strainmeter 8, measurement is numbered the strain value ε of the country rock position corresponding to resistance strain gage of 1
1, as the foundation judging relaxation zone scope, store and record;
(25) will be numbered 2,3 ..., n resistance strain gage, according to the method for testing of step (24), record and be numbered 2,3 ..., n the strain value ε of country rock position corresponding to resistance strain gage
2..., ε
n-1, ε
n, record stores strain value data, as the foundation judging relaxation zone scope;
Test the strain value ε that 1# resistance strain gage is corresponding
1after, repeat step and test n-1 remaining resistance strain gage, the strain value tested out respectively is ε
2..., ε
n-1, ε
n, as the strain value ε of the corresponding country rock position of the n-th resistance strain gage
nafter record stores, whole test job terminates.
Step 103, distribution characteristics according to the strain value of different surrounding rock position, judge the scope of country rock position relaxation zone.
According to the test result of step 3, draw out the relation curve of country rock position and strain value ε, by distribution characteristics and the variance analysis of the strain value at the inner diverse location place of country rock, judge the scope of country rock position relaxation zone: the country rock between strain peak to drilling orifice place is within the scope of relaxation zone.
The country rock degree of depth of the preferred embodiment of the present invention and the changing trend diagram of strain value see Fig. 4, Fig. 4.Horizontal ordinate is the distance in resistance strain gage distance aperture in the degree of depth of country rock and testing element, and ordinate is the strain value of country rock.Country rock between strain peak to drill hole is within the scope of relaxation zone.
To those skilled in the art, obviously the invention is not restricted to the details of above-mentioned one exemplary embodiment, and when not deviating from spirit of the present invention or essential characteristic, the present invention can be realized in other specific forms.Therefore, no matter from which point, all should embodiment be regarded as exemplary, and be nonrestrictive, scope of the present invention is limited by claims instead of above-mentioned explanation, and all changes be therefore intended in the implication of the equivalency by dropping on claim and scope are included in the present invention.Any Reference numeral in claim should be considered as the claim involved by limiting.
In addition, be to be understood that, although this instructions is described according to embodiment, but not each embodiment only comprises an independently technical scheme, this narrating mode of instructions is only for clarity sake, those skilled in the art should by instructions integrally, and the technical scheme in each embodiment also through appropriately combined, can form other embodiments that it will be appreciated by those skilled in the art that.