CN108843331B - Slim hole joint release method for arranging under the equivalent drilling area of one kind - Google Patents
Slim hole joint release method for arranging under the equivalent drilling area of one kind Download PDFInfo
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D9/00—Tunnels or galleries, with or without linings; Methods or apparatus for making thereof; Layout of tunnels or galleries
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21C—MINING OR QUARRYING
- E21C41/00—Methods of underground or surface mining; Layouts therefor
- E21C41/16—Methods of underground mining; Layouts therefor
- E21C41/18—Methods of underground mining; Layouts therefor for brown or hard coal
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Abstract
The invention discloses slim hole joint release method for arranging under a kind of equivalent drilling area, are related to Surrounding Rock Control field during mine and tunnel excavation.It is by being converted into three slim holes for single large diameter borehole, and each slim hole area is identical and the sum of area is consistent with large diameter borehole area value, and effectively relief range is significantly improved.Pass through the intensity and strain energy transformation rule of sample under the different arrangement modes of analysis drilling, the range and release effect of the distressed zone of comparative analysis slim hole various combination mode and single large diameter borehole, determine slim hole optimum combination mode under equivalent drilling area；Using the ratio of its bore diameter and the spacing of wells under Numerical Method Study drilling triangle arrangement to release influential effect degree, the optimal proportion of bore diameter and the spacing of wells under drilling triangle arrangement is obtained.The present invention can be obviously improved release effect, significantly reduce collapse hole, card hole risk.
Description
Technical field
The present invention relates to Surrounding Rock Control fields during mine and tunnel excavation, and in particular under the equivalent drilling area of one kind
Slim hole joint release method for arranging.
Background technique
Currently, with the increase of coal mining intensity and mining depth, the complexity of coal field geology condition in addition, China's coal
Mine such as presses to increasingly sharpen at the threat of dynamic disasters with being hit, and seriously threatens Safety of Coal Mine Production and human life's property safety.
Existing theoretical and work place study discovery, reducing surrouding rock stress is to safeguard stable basic of deep tunnel.Existing bump is prevented
It controls technology mainly to include the following three types: first is that carrying out the pre- erosion control of globality using optimization development layout, without means such as coal pillar minings
The generation pressed with hitting；Second is that carrying out pointedly improving prop using the methods of supporting intensity or improvement support pattern is increased
Impact resistance；Third is that carrying out locality solution danger, the purpose is to reduce coal body product by changing coal (rock) body physico-mechanical properties
For the ability of fusion shape energy to reduce coal body shock hazard, main method includes drilling release, deep hole blasting etc..
Large diameter borehole release as a kind of typical country rock high stress solution danger technology there is its unique superiority to obtain extensively
General utilization.Drilling destressing method, which refers to, arranges gun drilling in coal seam to reduce ambient stress locating for country rock or change surrouding rock stress
Distribution shifts support pressure peak value to country rock deep, reduces the stress concentration degree of coal body, alleviates bump strength condition
And energy condition.Release drill as a kind of typical roadway surrounding rock stress transfer technology, simple process, easy for construction, engineering
It measures small, and effective compensation space can be provided for country rock dilatancy, be widely used in always in Rock Burst prevention and treatment.It is special
It is not the deep high stress tunnel for some extremely difficult maintenances, drilling release can still obtain preferable release control effect.
Existing research is mostly analyzed by three aspects such as laboratory test, numerical simulation and engineer application, Liu Jinhai
[forced-ventilated coal dust prevents and treats the mechanism of bump and applies [J] Chinese Journal of Rock Mechanics and Engineering, 2014, (04): 747-754.] grinds
Forced-ventilated coal dust prevention and treatment bump mechanism is studied carefully, has shown that its release effect is brighter with the increase of drilling hole amount and bore diameter
It is aobvious；Zhang Zhaomin [large diameter borehole release mechanism and its Reasonable Parameters research [D] University Of Science and Technology Of Shandong, 2011.] has carried out difference
Bore diameter size is to the law study for alleviating stress in coal bed accumulation under the conditions of adopting depth, it is believed that with the increase of bore diameter, lane
Road release effect is better；Li Jinkui [numerical simulation [J] the Xi'an Technology University journal pressed to drilling release prevention and treatment roadway bump,
2009,29 (4): 424-432] based on ADINA software simulation drilling depth tunnel vertical stress distribution characteristics, it is believed that drilling depth
Deeper, release effect is more obvious；Jia Chuanyang is [in large diameter borehole release mechanism room and numerical experimentation research [J] geotechnical engineering
Report, 2017,39 (06): 1115-1122] different drilling parameters are had studied based on indoor and numerical experimentation under the conditions of sample crackle expand
Spread state and crack number, it is believed that stress release caused by crack propagation penetrates through is the basic reason that drilling generates release effect；
Liu Honggang [numerical simulation and commerical test [J] coal journal of boreholes destressing technology in deep coal tunnel, 2007,32 (l): 34-
37.], Lan Yongwei [destressing borehole numerical simulation study [J] Liaoning Project Technology University journal, 2005,24 (supplementary issues): 275-
277.] influence of the factors such as drilling depth, spacing to release effect is further analyzed, it is found that the pressure relief vent of reasonable Arrangement can be with
Shift country rock high stress to deep.In practical engineering applications, Chen Feng [imitates destressing borehole measure using drilling cuttings method
Assay [J] geotechnical engineering journal of fruit, 2013, (S2): 266-270.] using drilling cuttings method, to demonstrate destressing borehole certain
Bump risk is reduced in degree；Song Xixian [the number of deep tunnel pressure relief vent and combining anchor supporting under energetic disturbance
Value simulation [J] Central South University journal (natural science edition), 201445 (9): 3158-3165.] in analysis drilling release effect machine
Pressure relief vent and combining anchor support technology are inquired on the basis of reason；[deep tunnel drilling release mechanism and key parameter are true by Wang Meng
Determine method and apply [J] coal journal, 2017,42 (05): 1138-1145.] using to FLAC3D software secondary development, analysis
Deep tunnel drills release mechanism, proposes using stress transfer effect and surrouding rock deformation control effect as release effect direct
Evaluation index.
In addition, also being retrieved to related patents, main results and existing pros and cons are as follows:
Application number: 201610972903.5 disclose a kind of deep high stress tunnel pressure relief support association based on drilling release
Control method is divided into a yield supporting, drilling three steps of release and secondary high-strength bolt-grouting support by sequence of the time.Needle
The difference that rear locating different times surrouding rock deformation mode is excavated to tunnel, is enclosed using different supportings and a reinforcing mode control stage
Rock deformation, gives full play to the supporting performance of country rock and supporting construction itself, reduces the large deformation of deep high stress tunnel country rock, real
Existing tunnel is steady in a long-term.
The prior art provide it is a kind of based on drilling unloading technology allowing pressure and high strong supporting and drilling release coordinate match
The Coordinated Control of the tunnel dynamic disaster prevention and treatment of conjunction, reduces roadway deformation amount under high stress complex geological condition, alleviates
A possibility that dynamic disaster.But the patent focuses on the research of suspension roof support and the release Coordinated Control that drills, Jin Jinti
A kind of method that can reduce tunnel dynamic disaster risk has been supplied, the environment such as working face are not particularly suited for, for the release that drills
Concrete condition is without further statement in detail, and secondary high strong supporting variorum slurry is reinforced and anchor pole rope strengthening supporting multiple stages,
Complicated operation.
Application number: 201310465569.0 disclose a kind of combined type coal uncovering method, disclosed method are as follows: work as stone
Door driving is met head on drill site of constructing to when hanging down with coal seam away from 10m in crossdrift, from drill site in coal seam construction drill, slot is pressed in drilling
Drilling and commonly drilling are alternatively arranged, and the combination that slot drills and commonly drills arranges that the uniform release for realizing coal body is anti-reflection.
Connecting leg extraction after the completion of drilling construction reduces gas bearing capacity and gas potential in coal seam.After gas drainage is up to standard, slot is bored
Hole injects cement mortar into coal body and strengthens coal body, realize the combination of slot release and reinforcing strengthening as inlet well.This hair
It is bright to can be reduced 30%~40% extinction project amount under conditions of ensuring safe coal-openning, it is significant shorten the gas drainage time and
Exposed coal period, safe coal-openning speed improve 40%~50%
The prior art is drilled by slot and is arranged with the combination commonly to drill, and the effective coverage of drilling is increased, real
It is anti-reflection to have showed the uniform release in coal seam, has significantly shortened the gas pre-drainage time.Strengthened by injecting cement mortar in drilling to slot
Coal body realizes slot release and the combination of reinforcing strengthening, in terms of reducing crustal stress and gas pressure, improving coal mass strength three
Comprehensively consider, eliminates stone door punching coal outburst hazard comprehensively.But between the patent focuses on slot drilling and commonly drills
Every arrangement, increases coal seam pressure relief and permeability improvement situation and then carry out joint-cutting bored grouting, realize the group of slot release and reinforcing strengthening
It closes, though reducing risk to a certain extent, does not consider that drilling was measured multipair improving stability of surrounding rocks in roadway and construction speed etc. and made
At influence and the drilling of existing high-ground stress environment easily there is the problems such as bit freezing, collapse hole, process flow is complicated, construct into
Degree is slow, and there are part drawbacks.
Application number: CN201610919336.7 discloses a kind of design method of array pitch between destressing borehole, and this method is divided into
Ambient stress between three step design destressing boreholes before array pitch firstly the need of assessment release place, calculates working face (tunnel) and encloses
Petrous branch bearing capacity peak value σpAnd its position Lp；Choose LpLocate country rock as analysis object, is parsed using revised country rock elastoplasticity
Solution calculates drilling plastic zone radius rp, with rpAs the index of evaluation drilling single hole sphere of action, array pitch is between determining drilling maximum
R≤2rp；Meanwhile drilling tangential stress σ is calculated using Elastic Plastic Analytical SolutionsθEvolution curve, take adjacent borehole tangential stress bent
The stress of line crosspoint is σm, with test site stress of primary rock σ0For evaluation index, determine that the condition of array pitch R between drilling is minimum is
σm≥σ0.This method is easy to operate, practical, can effectively improve the accuracy of array pitch design between destressing borehole, reduce drillman
Cheng Liang can be applied to high stress tunnel release, Controlling of Coal Outburst and the fields such as high gas layer is anti-reflection.
The determination method of array pitch, improves array pitch accuracy between destressing borehole between the prior art provides effectively, reduces
Workload, but do not consider to disturb caused by country rock and existing high-ground stress ring in large aperture destressing borehole work progress yet
Easily there is the problems such as bit freezing, collapse hole in border drilling, can still impact to safe construction.
Above-mentioned experiment of machanics, numerical simulation and engineering practice show to drill release effect and bore diameter, drilling hole amount,
Drilling depth etc. is closely related, increases bore diameter, quantity and depth, can improve release effect.However in engineering practice, with
The increase of surrouding rock stress, be easy collapse hole, bit freezing in major diameter destressing borehole drilling process, difficulty increases year by year when drilling, makes
It obtains speed of application to be remarkably decreased, release effect is undesirable；Meanwhile blindly increase destressing borehole diameter or quantity not only increase worker
The amount of labour, reduce roadway construction progress, and can generate roadway surrounding rock intensity and once supporting structure compared with large disturbances, be easy to lure
Hair bump or initiation large deformation of roadway cause lame advanced supporting to fail, and increase risk, are not suitable for high-ground stress area
The needs that efficiently produce of safety of coal mines, affect the popularization and application of the technology.
Summary of the invention
In order to solve above-mentioned defect existing in the prior art, the invention proposes minor diameters under a kind of equivalent drilling area
Drill joint release method for arranging, can be obviously improved release effect, significantly reduces collapse hole, card hole risk, avoids simultaneously
Roadway surrounding rock intensity and once supporting structure are generated compared with large disturbances, construction technology is simplified.
To achieve the above object, required the technical issues of overcoming, has:
Major diameter destressing borehole in the prior art is easy collapse hole, bit freezing in drilling process, and difficulty increases year by year when drilling
Add, so that speed of application is remarkably decreased, release effect is undesirable；Meanwhile blindly increase destressing borehole diameter or quantity also can not
Row, blindly increasing the consequence directly resulted in is not only to increase the amount of labour of worker, reduces roadway construction progress, and again can
Roadway surrounding rock intensity and once supporting structure are generated compared with large disturbances, are easy to induce bump or cause large deformation of roadway to cause
Lame advanced supporting failure, increases risk, is not suitable for the needs that safety of coal mines efficiently produces.Therefore, a kind of conjunction how is determined
The method for arranging of reason is the most important thing that the present invention studies.
In order to solve the above technical problems, the invention adopts the following technical scheme:
Slim hole joint release method for arranging under a kind of equivalent drilling area, successively the following steps are included:
A. it selects a certain bump mine to be sampled, the coal cinder fetched is processed into the cylindrical coal sample of standard, is adopted
Single shaft, three axis, stretching and shearing mechanical test are carried out to coal sample with rigid mechanics machine, obtain the basic mechanical ginseng of coal sample
Number；
B. proportion acquisition and class coal petrography material similar in raw coal sample mechanical property, and it is made into rectangular test specimen,
Mechanical test is carried out after test specimen drying；
C. minor diameter combination drilling under single large diameter borehole and equivalent drilling area, the group of minor diameter combination drilling are made
Conjunction mode is transversely arranged, vertical array or triangle arrangement, carries out uniaxial loading examination to the minor diameter combination drilling of various combination
It tests, obtains its load-deformation curve, calculate the strength degradation index and energy dissipation index of different drilling test specimens, research is different
The intensity and energy evolution rule of drilling test specimen, the destruction of the single large diameter borehole of comparative analysis and minor diameter combination drilling test specimen
Form and release effect, so that it is determined that slim hole optimum combination mode；
D. the optimum way combination of the triangle arrangement of the minor diameter combination drilling test specimen obtained for mechanical test, based on number
It is worth simulation softward, analyzes and closed when determining roadway construction when slim hole triangle is arranged under best equivalence drilling area and the area
Array pitch between reason, in D/B=2.0, drilling hole stress and influence distribution reach maximum value, obtain best release scheme and apply
With scene；
E. selection suitable position arrangement survey station carry out real time monitoring, monitor lead abutment pressure within the scope of roof and floor from
Situations such as macroscopic deformation of layer, the confining pressure amount of shifting near, stress monitoring and drilling deformation monitoring and coal body, according to field monitoring data
It timely feedbacks, according to data analysis result, adjusts best equivalence drilling area, bore diameter D, spacing B and various combination in due course
Release effect of the spacing to be optimal.
The direct bring advantageous effects of above-mentioned technical proposal are as follows:
Single large diameter borehole is converted into several slim holes, the sum of slim hole area is kept to bore with major diameter
Hole face product value is consistent, is drilled the intensity and strain energy transformation rule of sample under different arrangement modes by analysis of experiments, and be based on
Numerical simulation scheme result can obtain best release effect when obtaining slim hole triangle arrangement.It is carried out by inventor big
Measure laboratory laboratory experiment, numerical simulation and field application the result shows that, convert large scale drilling to various forms of equivalent
Area small bore combining form can be obviously improved release effect especially for triangular arrangement mode, and significant decrease is collapsed
Hole, card hole risk, while avoiding and roadway surrounding rock intensity and once supporting structure are generated compared with large disturbances, simplify construction work
Skill increases speed of application, has significant economic and social benefit.
Used drilling release evaluation index, proposes strength degradation index concept and novel energy dissipative exponent, by force
Degree reduction index reduces coal (rock) body breaking strength to quantitative assessment drilling release, and it is strong to be defined as complete sample peak value
The ratio of degree and drilling sample peak strength, its calculation formula is:
Kσ=(σ1-σ2)/σ1
In formula: σ1For complete sample peak strength；σ2For the sample peak strength that drills.
Energy dissipation index reduces coal (rock) physical efficiency amount levels of accumulation to quantitative assessment drilling release, is defined as complete
Before sample peak before strain energy and drilling sample peak strain energy ratio of the difference with strain energy before complete sample peak, calculation formula
Are as follows:
KE=(U1-U2)/U1
In formula: U1For strain energy before complete sample peak；U2For strain energy before drilling sample peak.
Strength degradation index refers in complete sample peak strength σ1Under the premise of certain, drilling sample peak strength is smaller,
Its strength degradation index is bigger, and release effect is better.
Energy dissipation index refers to the strain energy U before complete sample peak1Under the premise of certain, in the sample loading procedure that drills
The energy of dissipation is more, and energy dissipation index is bigger, and release effect is better.
As a preferred solution of the present invention, the size of cylindrical coal sample is Φ 50mm × 100mm.
As another preferred embodiment of the invention, the length-width ratio of step b test specimen is 2:1.
Further, the combination of minor diameter combination drilling test specimen is triangle arrangement.
Further, in step c, the sum of area of minor diameter combination drilling and large diameter borehole area equation, such as formula
(1), it may be assumed that
πR2=n π r2 (1)
In formula: R is large aperture destressing borehole radius, and n is small-bore drilling hole amount, and r is small-bore boring radius.
Advantageous effects brought by the present invention are as follows:
Compared with prior art, Surrounding Rock Control is constructed during the present invention can be used for mine and tunnel excavation, is related to one kind
Slim hole joint release arrangement and construction method under equivalent drilling area.The present invention converts large scale drilling to not
Equivalent area small bore combining form with form can be obviously improved release effect especially for triangular arrangement mode,
Collapse hole, card hole risk are significantly reduced, while avoiding and roadway surrounding rock intensity and once supporting structure is generated compared with large disturbances, letter
Construction technology is changed, has increased speed of application, reduced number of devices in tunnel, has mitigated worker's working strength, improve existing large aperture
The deficiency of drilling release, reduces security risk.Drilling release effect can be increased substantially in application at the scene, in the art
It is interior that there is wide applicability, there is significant economic and social benefit.
Detailed description of the invention
The present invention will be further described with reference to the accompanying drawing:
Fig. 1 is slim hole joint release arrangement flow chart under a kind of equivalent drilling area of the invention；
(2a), (2b), (2c) are drilling release support pressure overall structure schematic illustrations in the present invention in Fig. 2；
Fig. 3 is complete sample and drilling sample stress-strain curve；
Fig. 4 is drilling hole stress distribution map under uniaxial compressed state；
Fig. 5 is the adjacent two drilling tangential stress component of equal diameter；
(6a), (6b) are different form intensity schematic diagrames when testing in the present invention in Fig. 6；
(7a), (7b) are test parameters and drilling combination figure in Fig. 7；
Fig. 8 is intermediate cam arrangement form drilling release numerical simulation figure of the present invention；
In figure, 1, mining induced stress curve before release, 2, mining induced stress curve after release, 3, destressing borehole, 4, coal seam；5, complete
Load-deformation curve before whole sample peak value, 6, load-deformation curve before sample peak value of drilling, 7, strain energy before complete sample peak
U1, 8, drilling sample peak before strain energy U2, 9, complete sample and drilling sample peak before strain energy difference DELTA U, 10, large aperture cloth
Set destressing borehole strength characteristic, 11, lateral arrangement destressing borehole strength characteristic, 12, be vertically arranged destressing borehole strength characteristic,
13, triangular form arranges destressing borehole strength characteristic, 14, D bore diameter, 15, the hole B back gauge, 16, compression strength, 17, springform
Amount, 18, strain energy before peak, 19, triangle drilling release simulate coverage.
Specific embodiment
The invention proposes slim hole joint release method for arranging under a kind of equivalent drilling area, in order to make the present invention
The advantages of, technical solution it is clearer, clear, elaborate combined with specific embodiments below to the present invention.
It elaborates first to present invention drilling pressure release mechanism.
Drilling destressing method refers to that gun drilling is arranged in coal seam answers to reduce ambient stress locating for country rock or change country rock
Power distribution, shifts support pressure peak value to country rock deep, reduces the stress concentration degree of coal body, alleviates bump intensity item
Part and energy condition, drill in the present invention release support pressure overall structure principle such as Fig. 2 (2a), (2b), shown in (2c).1 is
Mining induced stress curve before release, 2 be mining induced stress curve after release, and 3 be destressing borehole, and 4 be coal seam.
Slim hole joint release arrangement and construction method under the equivalent drilling area of one kind, which is characterized in that this
Invention technical principle involved when solving its technical problem is comprising the release mechanism that drills, single hole release mechanism and porous unloads
Press reason.
1) drill release mechanism
The release that drills changes coal (rock) body physico-mechanical properties mechanism as shown in figure 3, curve 5 is complete sample peak value in figure
Preceding load-deformation curve, curve 6 are load-deformation curve before drilling sample peak value, and 7 be strain energy U before complete sample peak1, 8
For strain energy U before drilling sample peak2, 9 be the difference DELTA U, σ of strain energy before complete sample and the sample peak that drills1For complete sample peak
It is worth intensity, σ2For the sample peak strength that drills, ε1For the corresponding strain value of complete sample peak strength, ε2For the sample peak value that drills
The corresponding strain value of intensity.From the figure 3, it may be seen that drilling release main function is to reduce sample breaking strength and energy accumulation
Ability.Breaking strength can be obtained by load-deformation curve, and strain energy can be obtained by following formula before peak:
2) single hole release mechanism
Drilling hole stress σ under laboratory test uniaxial compressed state2=0, thus θ=0 °, the radial stress on 90 ° of axis with
The distribution map of tangential stress, as shown in Figure 4.
There is Tension Stress Zone in drilling top/bottom part, and the maximum principal stress coefficient of concentration in drilling two sides reaches 3.When θ=90 °
When, tensile stress is maximum, and after drilling is excavated, stress concentration occurs in drilling top/bottom part, when ambient stress is more than drilling surrouding rock stress,
Drilling destroys, and provides space for Stress relieving of surrounding rocks, plays the role of release.
3) porous release mechanism
The stress of adjacent two drilling and coverage superposition distribution.It is by one borehole tangential stress distribution form it is found that remote
From the trend that the distribution of drill center tangential stress has decaying, when being more than the elastic limit of drilling country rock, country rock enters modeling
Character state.Generally to be greater than 5% stress of primary rock position as the radius of influence, when the adjacent drilling in same stress field, if two
The distance between drilling is greater than 2 times of radiuses of influence, then not will form the influence being overlapped mutually, the stress of tunnel-surrounding between drilling
Distribution also will and the case where single hole it is essentially identical.Conversely, the plastic zone that drilling country rock generates generates superposition, drilling is enclosed at this time
The destruction of rock has regional synergistic effect.
Fig. 5 generates interactional relational graph when showing adjacent two spacing of wells less than 2 times of radiuses of influence.B is enabled in figure
=D, then the tangential stress coefficient of concentration generated on periphery between two drillings is 3.26, and is 2.5 in single hole, as dashed lines
It is shown.41.7% is increased in the midpoint factor of stress concentration of the spacing of wells for 1.7,1.2 when compared to single hole.It is possible thereby to
Find out, drill synergy release when, the factor of stress concentration of surrounding that drill is greater than one borehole, in two drilling intermediate points
Place, the concentrated stress of drilling is than there is apparent growth when one borehole, the level of breakage of drilling is stronger, release excellent result,
Therefore drilling synergy release effect is better than single drilling release.
Drilling release can reduce the ability of coal (rock) body breaking strength and energy accumulation, but be reduced to what degree
It is a critical issue, therefore, further, under a kind of equivalent drilling area slim hole joint release arrangement and applies
Work method, including the present invention solve drilling release evaluation index used by its technical problem, which is characterized in that propose intensity
It is reduced index concept and novel energy dissipative exponent, strength degradation index reduces coal (rock) body pole to quantitative assessment drilling release
Breakdown strength is limited, the ratio of complete sample peak strength and the sample peak strength that drills is defined as, its calculation formula is:
Kσ=(σ1-σ2)/σ1
In formula: σ1For complete sample peak strength；σ2For the sample peak strength that drills.
Energy dissipation index reduces coal (rock) physical efficiency amount levels of accumulation to quantitative assessment drilling release, is defined as complete
Before sample peak before strain energy and drilling sample peak strain energy ratio of the difference with strain energy before complete sample peak, calculation formula
Are as follows:
KE=(U1-U2)/U1
In formula: U1For strain energy before complete sample peak；U2For strain energy before drilling sample peak.
The strength degradation index refers in complete sample peak strength σ1Under the premise of certain, drilling sample peak strength is got over
Small, strength degradation index is bigger, and release effect is better.
The energy dissipation index refers to the strain energy U before complete sample peak1Under the premise of certain, drilling sample was loaded
The energy to dissipate in journey is more, and energy dissipation index is bigger, and release effect is better.
The present invention, slim hole joint release method for arranging under a kind of equivalent drilling area, as shown in Figure 1, successively wrapping
Include following steps:
A. it selects a certain bump mine to be sampled, the coal cinder fetched is processed into the cylinder of standard in laboratory
Coal sample (coal sample size Φ 50mm × 100mm) carries out single shaft, three axis, stretching and shearing to coal sample using rigid mechanics machine
Mechanical test obtains the basic mechanical parameter of coal sample.
B. using materials such as model plaster, SILICA FUME, calcium carbonate, proportion is obtained and class similar in raw coal sample mechanical property
Rectangular test specimen is made by experiment mould in coal petrography material, and the length-width ratio of test specimen is 2:1, carries out mechanics after test specimen drying
Test；
C. minor diameter combination drilling test specimen, minor diameter under single large diameter borehole and equivalent drilling area are made using electric drill
The combination that drills is three kinds of drilling hole transverse arrangement, vertical array and triangle arrangement forms, carries out uniaxial loading to drilling test specimen
Test obtains the load-deformation curve of drilling test specimen, and in order to more intuitively clearly illustrate research effect, we choose 20mm
It is analyzed for the test specimen condition of large aperture, as shown in Fig. 6 (6a), (6b), calculates the strength degradation index of different drilling test specimens
With energy dissipation index, in Fig. 6,10 arrange destressing borehole strength characteristic for large aperture, and 11 lateral arrangement destressing borehole intensity are special
Sign, 12 are vertically arranged destressing borehole strength characteristic, and 13 triangular forms arrange destressing borehole strength characteristic.The detailed test parameters with
Drilling combination is shown in Fig. 7 (7a), (7b), and the test parameters of sample is shown in Table 1 under the various combination mode that drills, and studies different brills
Intensity and the energy evolution rule of hole test specimen, the destruction shape of the single large diameter borehole of comparative analysis and minor diameter combination drilling test specimen
Formula and release effect, so that it is determined that slim hole optimum combination mode；
D. the optimum way combination of the slim hole triangle arrangement obtained for mechanical test, it is soft based on numerical simulation
Part is arranged between reasonable when analyzing roadway construction when determining slim hole triangle arrangement under best equivalence drilling area and the area
Away from D/B=2.0, drilling hole stress and influence distribution reach maximum value, and preferred triangle drilling arrangement simulation drawing is shown in figure
Shown in 8, best release scheme is obtained and application and scene, 19 simulate coverage for the triangle release that drills in Fig. 8.
E. selection suitable position arrangement survey station carry out real time monitoring, monitor lead abutment pressure within the scope of roof and floor from
Situations such as macroscopic deformation of layer, the confining pressure amount of shifting near, stress monitoring and drilling deformation monitoring and coal body, according to field monitoring data
It timely feedbacks, according to data analysis result, adjusts best equivalence drilling area, bore diameter D 14, the spacing B (hole B back gauge in due course
15) and release effect of the various combination spacing to be optimal from.
In Fig. 7, there is strain energy 18 before uniaxial compressive strength 16, elasticity modulus 17 and peak, by table 1 and Fig. 7 it is found that with complete
Sample is compared, and sample uniaxial compressive strength 16 reduces under the various combination that drills, drilling hole transverse arrangement, vertical array, triangle row
When column, compression strength is respectively 14.87MPa, 13.81MPa, 10.70MPa, strength degradation index is respectively 19.1%,
24.8%, 41.8%.When drilling hole transverse arrangement, vertical array, triangle arrangement, strain energy is respectively 0.040Jcm before peak-3、
0.043J·cm-3、0.021J·cm-3, energy dissipation index is respectively 36.5%, 31.8%, 66.7%.Three kinds of different groups
Under conjunction mode, when the triangle arrangement that drills, strain energy is reduced at most before peak strength and peak, and release effect is best.
In conjunction with can be seen that in Fig. 6,7 in order to more intuitively clearly illustrate research effect, the large aperture 20mm test specimen is chosen
It is analyzed for condition, when bore diameter is 20mm, release area is S=314mm2, drill under various combination mode and unload
Pressure surface accumulates S=339.12mm2, the two substantially close to, it is believed that be equivalent drilling area.It is 20mm compared to single borehole diameter
When, strain energy increases before transversely arranged under equivalent drilling area and vertical array drilling sample peak strength and peak, and drilling is horizontal
Increase by 18% to sample peak strength when arrangement, strain can increase 14.3% before peak；Sample uniaxial compressive when the vertical array that drills
Intensity increases by 9.6%, and strain can increase 22.9% before peak, illustrates that the equivalent drilling area drilling release effect that places an order is better than cross
To arrangement and vertical array；Strain energy is obvious before triangle arrangement arranges drilling sample peak strength and peak under equivalent drilling area
Reduce, peak strength reduces 15.1%, and strain energy reduces 40.0% before peak, illustrates triangle arrangement release under equivalent drilling area
Effect is significantly greater than single borehole.
Further, the sum of above-mentioned slim hole area should with large scale drill area equation, i.e.,
πR2=n π r2,
In formula: R is large aperture destressing borehole radius, and n is small-bore drilling hole amount, and r is small-bore boring radius.
That is:
Further, said combination mode experiment proves that, numerical simulation and field application, final determine select equivalent brill
The release effect triangle arrangement that drills under hole area is more significant compared with other arrangement release effects, under equivalent drilling area
Triangle arranges that bore mode release is optimal case；
It is since it is considered that due in coal body that the similar class coal petrography material of the used mechanical property of above-mentioned steps b, which carries out test,
There are a large amount of initial fissures in portion, are influenced in addition by adopting, cause raw coal sample mechanical property discreteness larger, it is difficult to reality
It tests result effectively to be compared, and situations such as raw coal sample is difficult into standard large-sized rectangle sample.
Ore pressure monitor station reasonable Arrangement according to actual needs is arranged required for above-mentioned steps e, auxiliary is using drilling when necessary
Endoscope monitoring drilling convergent.
Further, legal equivalents area, arrangement and drilling D, B are carried out by using numerical simulation and laboratory test
The selection of size.Common combinations such as large scale drills, and three holes are horizontally-arranged, three hole vertical setting of types and triangle arrangement etc., as shown in Figure 6.Specifically
Using materials such as gypsum, SILICA FUME, calcium carbonate, proportion obtains and class coal petrography material similar in raw coal sample mechanical property selecting method
Material, production class coal test specimen carries out laboratory test, by trying under the different arrangements of drilling under the analysis of experiments geological conditions
The strength characteristic and strain energy transformation rule of sample, study strength degradation index and energy dissipation index under the conditions of specific geology, into
And it obtains the release effect triangle arrangement that drills under equivalent drilling area and is substantially better than other arrangements；Then it is based on numerical value
Simulation softward, it is reasonable when determining roadway construction when slim hole triangle is arranged under best equivalence drilling area and the area to analyze
Between array pitch, in D/B=2.0, drilling hole stress and influence distribution reach maximum value, obtain best release scheme and application with
Scene；Finally, based on field monitoring, feedback and correcting best equivalence drilling area, bore diameter D, spacing B and each cam combination
Release effect of the spacing to be optimal.Advantageous effects brought by the present invention are as follows: compared with prior art, the present invention can
It constructs for Surrounding Rock Control during mine and tunnel excavation, is related to slim hole joint release under the equivalent drilling area of one kind
Arrangement and construction method.Large scale drilling is converted various forms of equivalent area small bore combining forms by the present invention,
Especially for triangular arrangement mode, it can be obviously improved release effect, collapse hole, card hole risk is significantly reduced, keep away simultaneously
Exempt to generate compared with large disturbances roadway surrounding rock intensity and once supporting structure, simplified construction technology, increased speed of application, has reduced
Number of devices in tunnel mitigates worker's working strength, improves the deficiency of existing large-diameter borehole release, reduces security risk.?
Drilling release effect can be increased substantially in field application, there is wide applicability in the art, had significant
Economic and social benefit.
The test parameters of sample under the drilling various combination mode of table 1
Supplementary explanation: the aperture 20mm, the selection of test specimen manufactured size are selected in this paper specific embodiment and Figure of description
The conditions such as 2:1 and D, B ratio are analyzed, and are only to comprehensively consider the tool such as scene, laboratory concrete condition and article length
Body reason, and the concrete condition occurred in this case, for more clear intuitive expression, the concrete example of progress is analyzed,
Do not play restriction effect, it is not excluded that a possibility that different parameters are selected according to different geology, test and analog case.
It should be further noted that specific embodiment described herein is only to made by spirit of the invention
It illustrates.Those skilled in the art can make various modifications to described specific embodiment
Or supplement or be substituted in a similar manner, however, it does not deviate from the spirit of the invention or surmounts the appended claims determines
The range of justice.
Claims (5)
1. slim hole joint release method for arranging under a kind of equivalent drilling area, which is characterized in that successively include following step
It is rapid:
A. it selects a certain bump mine to be sampled, the coal cinder fetched is processed into the cylindrical coal sample of standard, using rigid
Property mechanics machine to coal sample carry out single shaft, three axis, stretching and shear mechanical test, obtain the basic mechanical parameter of coal sample；
B. proportion acquisition and class coal petrography material similar in raw coal sample mechanical property, and it is made into rectangular test specimen, to test specimen
Mechanical test is carried out after drying；
C. minor diameter combination drilling test specimen under single large diameter borehole and equivalent drilling area, the group of minor diameter combination drilling are made
Conjunction mode is transversely arranged, vertical array, triangle arrangement, carries out uniaxial loading test to drilling test specimen, obtains its stress-strain
Curve calculates the strength degradation index and energy dissipation index of different drilling test specimens, studies the intensity and energy of different drilling test specimens
Evolution is measured, the single large diameter borehole of comparative analysis and minor diameter combine the failure mode and release effect of drilling test specimen, from
And determine slim hole optimum combination mode；The strength degradation index is complete sample peak strength and drilling sample peak
It is worth the ratio of intensity, calculation formula such as formula (1):
Kσ=(σ1-σ2)/σ1 (1)
In formula (1): σ1For complete sample peak strength；σ2For the sample peak strength that drills；
The energy dissipation index be complete sample peak before strain energy with drill sample peak before strain energy difference with completely trying
The ratio of strain energy before sample peak, calculation formula such as formula (2):
KE=(U1-U2)/U1 (2)
In formula: U1For strain energy before complete sample peak；U2For strain energy before drilling sample peak；
D. the optimum way combination of the triangle arrangement of the minor diameter combination drilling test specimen obtained for mechanical test, is based on Numerical-Mode
Quasi- software, between reasonable when roadway construction when analyzing slim hole triangle arrangement under determining best equivalence drilling area and the area
Array pitch, when bore diameter D and spacing of wells B meet D/B=2.0, drilling hole stress and influence distribution reach maximum value, obtain
To best release scheme and using on site；
E. selection suitable position arrangement survey station carry out real time monitoring, monitor lead abutment pressure within the scope of roof and floor absciss layer,
The macroscopic deformation situation of the confining pressure amount of shifting near, stress monitoring and drilling deformation monitoring and coal body, it is timely according to field monitoring data
Feedback adjusts best equivalence drilling area, bore diameter D, spacing B and various combination spacing according to data analysis result in due course
With the release effect being optimal.
2. slim hole joint release method for arranging under the equivalent drilling area of one kind according to claim 1, feature
Be: the size of the cylinder coal sample is Φ 50mm × 100mm.
3. slim hole joint release method for arranging under the equivalent drilling area of one kind according to claim 1, feature
Be: the length-width ratio of test specimen described in step b is 2:1.
4. slim hole joint release method for arranging under the equivalent drilling area of one kind according to claim 1, feature
Be: the combination of the minor diameter combination drilling test specimen is triangle arrangement.
5. slim hole joint release method for arranging under the equivalent drilling area of one kind according to claim 1, feature
It is: in step c, the sum of area of minor diameter combination drilling and the large diameter borehole area equation, such as formula (3), it may be assumed that
πR2=n π r2 (3)
In formula: R is large aperture destressing borehole radius, and n is small-bore drilling hole amount, and r is small-bore boring radius.
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