CN115045660B - Deep hole blasting fracturing method and system for top plate of large-dip angle stope face - Google Patents
Deep hole blasting fracturing method and system for top plate of large-dip angle stope face Download PDFInfo
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- 238000005422 blasting Methods 0.000 title claims abstract description 83
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
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Abstract
The application discloses a deep hole blasting fracturing method and system for a top plate of a large-dip angle stope face, wherein the method comprises the following steps: dividing a pressure relief grade area of a stoping roadway according to the stoping direction of the stoping working face with a large inclination angle; collecting characteristic parameters of a coal seam roof stratum in a pressure relief grade area, and determining a target blasting fracturing stratum position; calculating the roof elastic energy distribution characteristics of the target blasting fracturing rock horizon; based on the elastic energy distribution characteristics, setting a roof blasting fracturing parameter of a pressure relief grade area; and (3) implementing a deep hole blasting fracturing method of the top plate of the large-dip angle stope face according to the top plate blasting fracturing parameters, so as to realize pre-fracturing of the top plate of the stope face before mining. The blasting fracturing effect of the thick hard top plate of the large-dip angle stoping face is effectively improved, the pertinence of top plate blasting fracturing can be improved, the risk of stoping tunnel impact dynamic disasters caused by dynamic load disturbance generated by breaking of the thick hard top plate is reduced, and the life safety coefficient of staff of the stoping face is improved.
Description
Technical Field
The application relates to the technical fields of coal mining and coal mine safety, in particular to a deep hole blasting fracturing method and system for a top plate of a large-dip angle stope face.
Background
The large-dip angle stoping face is affected by the dip angle of the coal seam, and the roof overlying rock structure is quite different from that of the conventional stoping face, particularly the accumulation area of roof elastic energy is not in the geometric center of the stoping face, so that the specificity of the overlying rock breaking of the large-dip angle stoping face is caused. Because of the special overlying strata structure and the special elastic energy accumulation area during the stoping of the large-dip-angle working face, when a hard and thick top plate is arranged on the large-dip-angle working face, the breaking step distance of the top plate can be increased, the elastic energy released during breaking is increased, the dynamic load disturbance range generated by breaking is wider, and the safety stoping of the working face is seriously threatened. At present, a method for controlling a thick hard top plate by deep hole blasting pre-cracking of the top plate is generally adopted, but the method has good use effect on horizontal and near-horizontal coal seam working surfaces, and for a large-dip angle stoping working surface, due to the special overlying rock structure of the top plate and the special elastic energy accumulation area, conventional blasting cracking often cannot reach an expected effect, even abnormal increase of stress can be caused, and the risk of disasters is artificially increased. Therefore, the method aims at the special overlying strata structure of the large-dip angle stope face, the special roof elastic energy accumulation area, the accurate blasting of the elastic energy accumulation area of the coal layer thickness hard roof is realized through theoretical calculation and other methods, the blasting fracturing effect of the large-dip angle stope face thick hard roof is improved, meanwhile, the pertinence of roof blasting fracturing can be improved, the impact power disaster risk of stope caused by dynamic load disturbance generated by the breaking of the thick hard roof is reduced, and the life safety coefficient of stope face workers is improved, so that the defects in the prior art are overcome.
Disclosure of Invention
The application provides a deep hole blasting fracturing method and system for a top plate of a large-dip angle stope face, which are used for solving the technical problems existing in the prior art, dividing the pressure relief grade area of the stope face roadway, determining the blasting fracturing layer and area, improving the pertinence of the top plate blasting fracturing, reducing the impact dynamic disaster risk of the stope roadway caused by dynamic load disturbance generated by the breaking of a thick hard top plate, and are the research directions of the industry.
In order to achieve the above purpose, the application provides a deep hole blasting fracturing method for a top plate of a large-dip angle stope face, which comprises the following steps:
dividing a pressure relief grade area of a stoping roadway according to the stoping direction of the stoping working face with a large inclination angle;
collecting characteristic parameters of a roof stratum of the coal seam in the pressure relief grade area, and determining a target blasting fracturing stratum position;
calculating the roof elastic energy distribution characteristics of the target blasting fracturing rock horizon;
based on the elastic energy distribution characteristics, setting a roof blasting fracturing parameter of the pressure relief grade area;
and according to the roof blasting fracturing parameters, implementing a deep hole blasting fracturing method of the roof of the large-dip angle stope face to realize the pre-fracturing of the roof of the stope face before mining.
Preferably, the method for dividing the pressure relief grade area comprises the following steps:
K＝kZ＝k 1 k 2 k 3 k 4 k 5 ηH
wherein K represents the stress load value of surrounding rock of the stoping roadway; k represents the stress concentration coefficient of the stope; z represents the original stress value of the stope; h represents the thickness of the overburden; η represents the volume weight of the overburden; k (k) 1 Representing a stress concentration coefficient in a range of 30m in the vicinity of the fold structure; k (k) 2 Representing a stress concentration coefficient in a range of 30m in the vicinity of the fault structure; k (k) 3 Representing the concentration coefficient of the fixed supporting pressure in the coal body around the roadway; k (k) 4 The stress concentration coefficient within the range of 100m of the square area of the working surface is expressed; k (k) 5 The stress concentration coefficient in the range of the working surface period pressing area 20m is shown.
Preferably, the method for determining the target blasting fracturing rock stratum position comprises the following steps:
selecting a roof drilling detection point in each pressure relief grade area;
detecting the drilling detection points of each roof to obtain detection results of the attribute and the physical and mechanical parameters of the roof strata of the coal bed;
according to the detection result, determining a blasting fracturing target horizon by adopting a formula (1) and a formula (2):
in (y) j ) n Expressed as the load of the j-th roof against the n-th roof; j, n, i are respectively represented as roof strata serial numbers; e (E) n ，t n The elastic modulus and the thickness of the n-th layer of overlying strata are respectively expressed; η (eta) n The volume weight expressed as the n-th overburden;
and (3) judging the nth layer of the overburden layer meeting the relation of the formula (2) as a blasting fracturing target layer:
(y j ) n ＜(y j-1 ) n (2)。
preferably, the method for calculating the roof elastic energy distribution characteristics of the target blasted fractured rock horizon comprises the following steps:
constructing a mechanical model function of a roof structure of the large-dip angle stope face;
constructing a bending moment function at any point x of the top plate of the large-dip angle stope face according to the mechanical model function;
based on the relation between the elastic energy of the top plate and the bending moment, constructing an elastic energy calculation formula at any point x of the top plate of the large-inclination stope face;
and obtaining the elasticity distribution characteristics of the roof based on the mechanical parameter detection result and the elasticity calculation formula of the roof strata of the coal seam, and determining the fracturing area of the target fracturing strata.
Preferably, the method for constructing the mechanical model of the roof structure of the large-dip angle stope face comprises the following steps:
F＝F 1 +F 2 +F 3
F 3 ＝F d (x)＝-{ρg(λsinα+cosα)·[H 0 +(L+D L -x)sinα]}(D 1 +D L ≤x≤D)；
wherein F is 1 Represented as a linear load exerted by the roof strata in the plastic region of the recovery roadway; f (F) 2 Expressed as linear load applied to the roof strata after goaf gangue filling; f (F) 3 Represented as a stress load exerted by the roof strata in the direction of the inclination of the coal seam;
wherein P is x The lateral restraining force of the coal wall is represented by m, and the vertical height of the coal pillar of the working surface section is represented by m; c is expressed as cohesion between coal and rock; λ is expressed as the lateral stress coefficient;
expressed as the friction angle between the coal seam and the roof strata; d (D) L Expressed as the width of the plastic zone of the stope; [ delta ] y ，max]Expressed as a stope side support pressure peak; d (D) 1 Expressed as goaf gangue filling area width; d is expressed as the working surface incline length; f (F) d (0) Represented as the load of the overburden on the suspended ceiling at the origin; ρ is represented as the average density of the overburden; g is expressed as gravitational acceleration; alpha is expressed as the stope face inclination; h 0 Expressed as the boundary burial depth on the stope face.
Preferably, the method for constructing the bending moment function at any point x of the top plate of the large-dip angle stope face comprises the following steps:
preferably, the method for constructing the elastic energy calculation formula at any point x of the top plate of the large-dip angle stope face comprises the following steps:
wherein EI is bending rigidity, E is elastic modulus, and I is moment of inertia; t is a constant.
The application also provides a deep hole blasting fracturing system of a top plate of a large-dip angle stope face, which comprises: the device comprises a dividing module, an acquisition module, a calculation module, a positioning module and an implementation module;
the dividing module is used for dividing the pressure relief grade area of the stoping roadway according to the stoping direction of the stoping working face with the large inclination angle;
the acquisition module is used for acquiring characteristic parameters of the coal seam roof strata in the pressure relief grade area and determining a target blasting fracturing strata position;
the calculation module is used for calculating the roof elastic energy distribution characteristics of the target blasting fracturing rock horizon;
the positioning module is used for formulating a roof blasting fracturing parameter of the pressure relief grade area based on the elastic energy distribution characteristics;
the implementation module is used for implementing a deep hole blasting fracturing method of the top plate of the large-dip angle stope face according to the top plate blasting fracturing parameters, and realizing pre-fracturing of the top plate of the stope face before mining.
Compared with the prior art, the application discloses the following technical effects:
according to the method, the pressure relief areas of the large-dip angle stoping working face are systematically classified, the drilling coring mode is adopted to determine the blasting fracturing target horizon, the roof elastic energy distribution characteristics and the fracturing target areas are obtained through theoretical calculation, the pressure relief parameters of the areas with different pressure relief grades are formulated, and the deep hole blasting fracturing pressure relief of the roof of the large-dip angle stoping working face based on roof elastic energy partition is realized. Through this application, can effectively improve the blasting of the thick hard roof of big inclination stope face and lead to the fact the effect, can improve the pertinence that the roof blasting led to the fact simultaneously, reduce the stope tunnel that leads to the fact by the dynamic load disturbance that thick hard roof brokenly and lead to the fact and strike dynamic disaster risk, improved stope face staff's life safety factor.
Drawings
For a clearer description of the technical solutions of the present application, the drawings that are required to be used in the embodiments are briefly described below, it being evident that the drawings in the following description are only some embodiments of the present application, and that other drawings can be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a schematic flow chart of a deep hole blasting fracturing method implemented by the method;
FIG. 2 is a schematic diagram of the division results of different pressure relief grade areas of the stope face roof of the present application;
FIG. 3 is a schematic cross-sectional view of a deep hole blast hole arrangement trend of a top plate of a large-dip angle stope face of the present application;
FIG. 4 is a schematic plan view of a deep hole blast hole arrangement of a top plate of a large-dip angle stope face according to the present application;
FIG. 5 is a schematic diagram of a large dip angle stope face synthetic columns of a mine according to the present application;
FIG. 6 is a schematic diagram of the elastic energy distribution characteristics of a roof of a mining face with a large inclination angle of a certain mine;
FIG. 7 is a schematic diagram of a deep hole blasting fracturing hole arrangement of a roof of a mining face with a large inclination angle;
FIG. 8 is a schematic diagram of analysis of microseismic data after roof blasting fracturing of a mining face with a large inclination angle;
fig. 9 is a schematic diagram of a system structure for deep hole blasting fracturing of a top plate of a large-dip angle stope face.
Detailed Description
The following description of the embodiments of the present application will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all, of the embodiments of the present application. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are within the scope of the present disclosure.
In order that the above-recited objects, features and advantages of the present application will become more readily apparent, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments that are illustrated in the appended drawings.
Example 1
As shown in fig. 1, the specific flow of the deep hole blasting fracturing method for the top plate of the large-dip angle stope face of the present application includes the following steps:
s1, dividing a pressure relief grade area of a stoping roadway according to the stoping direction of a stoping working face with a large inclination angle
As shown in fig. 2, a schematic diagram of a division result of different pressure relief grade areas of a top plate of a stope face of the present application, a method for dividing the different pressure relief grade areas includes:
K＝kZ＝k 1 k 2 k 3 k 4 k 5 ηH
wherein K represents the stress load value of surrounding rock of the stoping roadway; k represents the stress concentration coefficient of the stope; z represents the original stress value of the stope; h represents the thickness of the overburden; η represents the volume weight of the overburden; k (k) 1 The stress concentration coefficient in the range of 30m near the fold structure is represented, the value is 1.2 when the fold structure exists in the stoping roadway area, and the value is 1.0 when the fold structure does not exist in the stoping roadway area; k (k) 2 Representing stress concentration coefficients in a range of 30m near the fault structure, wherein the value of the stress concentration coefficient is 1.2 when the fault structure exists in the stoping roadway area, and the value of the stress concentration coefficient is 1.0 when the fault structure exists in the stoping roadway area; k (k) 3 The centralized coefficient of the fixed supporting pressure in the coal body around the roadway is represented, the value is 1.2 when the stoping roadway is a temporary-empty roadway, and the value is 1.0 when the stoping roadway is a solid coal roadway; k (k) 4 The internal stress concentration coefficient within the range of 100m of the working face 'square' area is represented, the value is 1.2 when the working face 'square' exists in the stoping roadway area, and the value is 1.0 when the working face 'square' exists in the stoping roadway area; k (k) 5 The internal stress concentration coefficient within the range of 20m of the working face period pressing area is represented, the value is 1.2 when the working face period pressing is carried out in the stoping roadway area, and the value is 1.0 when the working face period pressing is not carried out in the stoping roadway area.
When Z is not less than K and not more than 1.4Z, the pressure relief grade of the stoping roadway is S class;
when K is more than 1.4Z and less than or equal to 2.0Z, the pressure relief grade of the stoping roadway is SS;
and when K is more than 2.0Z, the pressure relief grade of the stoping roadway is SSS.
S2, collecting characteristic parameters of the coal seam roof strata in the pressure relief grade area, and determining target blasting fracturing strata positions:
s2.1, selecting a roof drilling detection point in each pressure relief grade area;
s2.2, detecting the drilling detection points of each roof, and obtaining detection results of the attribute and physical mechanical parameters of the roof strata of the coal bed;
s2.3, determining a blasting fracturing target horizon by adopting a formula (1) and a formula (2) according to the detection result:
in (y) j ) n Expressed as the load of the j-th roof against the n-th roof; j, n, i are respectively represented as roof strata serial numbers; e (E) n ，t n The elastic modulus and the thickness of the n-th layer of overlying strata are respectively expressed; η (eta) n The volume weight expressed as the n-th overburden;
and (3) judging the nth layer of the overburden layer meeting the relation of the formula (2) as a blasting fracturing target layer:
(y j ) n ＜(y j-1 ) n (2)
the drilling depth of the top plate detection is 50m, and drilling holes are arranged perpendicular to the top plate of the roadway; record rock formation lithology and thickness t of roadway roof within 50m range 1 、t 2 …t i The method comprises the steps of carrying out a first treatment on the surface of the Finally, the distribution of deep hole blast holes of the top plate of the large-dip angle stope face is shown in fig. 3 and 4.
S3, calculating the roof elastic energy distribution characteristics of the target blasting fracturing rock layer:
s3.1, constructing a mechanical model function of a roof structure of the large-dip angle stope face;
s3.2, constructing a bending moment function at any point x of the top plate of the large-dip angle stope face according to the mechanical model function;
s3.3, constructing an elastic energy calculation formula at any point x of the top plate of the large-dip angle stope face based on the relation between the elastic energy of the top plate and the bending moment;
and obtaining the elasticity distribution characteristics of the roof based on the mechanical parameter detection result and the elasticity calculation formula of the roof strata of the coal seam, and determining the fracturing area of the target fracturing strata.
The construction of the mechanical model function of the roof structure of the large-dip angle stope face is as follows:
F＝F 1 +F 2 +F 3 (3)
F 3 ＝F d (x)＝-{ρg(λsinα+cosα)·[H 0 +(L+D L -x)sinα]}(D 1 +D L ≤x≤D) (6)
wherein F is 1 Represented as a linear load exerted by the roof strata in the plastic region of the recovery roadway; f (F) 2 Expressed as linear load applied to the roof strata after goaf gangue filling; f (F) 3 Represented as a stress load exerted by the roof strata in the direction of the inclination of the coal seam;
wherein P is x The lateral restraining force of the coal wall is represented by m, and the vertical height of the coal pillar of the working surface section is represented by m; c is expressed as cohesion between coal and rock; λ is expressed as the lateral stress coefficient;
expressed as the friction angle between the coal seam and the roof strata; d (D) L Expressed as the width of the plastic zone of the stope; [ delta ] y ， max ]Expressed as a stope side support pressure peak; d (D) 1 Expressed as goaf gangue filling area width; d is expressed as the working surface incline length; f (F) d (0) Represented as the load of the overburden on the suspended ceiling at the origin; ρ is represented as the average density of the overburden; g is expressed as gravitational acceleration; alpha is expressed as the stope face inclination; h 0 Expressed as the boundary burial depth on the stope face.
The bending moment function at any point x of the top plate of the large-dip angle stope face is constructed as follows:
the elastic energy calculation formula at any point x of the top plate of the large-dip angle stope face is constructed as follows:
wherein EI is bending rigidity, E is elastic modulus, and I is moment of inertia; t is a constant.
S4, based on the elastic energy distribution characteristics, formulating roof blasting fracturing parameters of the pressure relief grade area:
s4.1, when the pressure relief grade of the stoping roadway is S type: the deep hole blast holes of the top plate are arranged in three holes, the single hole explosive loading amount is 60kg, the depth of the blast holes is the target area of a fracturing target rock stratum, the blast holes are arranged in a group at intervals of 30m along the stoping direction of the working face, the blasting Kong Angjiao and the top plate of the roadway are respectively arranged at 50-70 degrees and-10-30 degrees, and the deflection angle of the blast holes and the stoping direction of the working face are arranged at 60-90 degrees;
s4.2, when the pressure relief grade of the stoping roadway is SS: the deep hole blast holes of the top plate are arranged in three holes, the single hole explosive loading amount is 60kg, the depth of the blast holes is the target area of a fracturing target rock stratum, the blast holes are arranged in a group at intervals of 20m along the stoping direction of the working face, the blasting Kong Angjiao and the top plate of the roadway are respectively arranged at 50-70 degrees and-10-30 degrees, and the deflection angle of the blast holes and the stoping direction of the working face are arranged at 60-90 degrees;
s4.3, when the pressure relief grade of the stoping roadway is SSS: the deep hole blast holes of the top plate are arranged in three holes, the single hole explosive loading amount is 60kg, the depth of the blast holes is the target area of a fracturing target rock stratum, the blast holes are arranged in a group at intervals of 10m along the stoping direction of a working face, the blasting Kong Angjiao and the top plate of the roadway are respectively arranged at 50-70 degrees and-10-30 degrees, and the deflection angle of the blast holes and the stoping direction of the working face are arranged at 60-90 degrees.
S5, implementing a deep hole blasting fracturing method of the top plate of the large-dip angle stope face according to the top plate blasting fracturing parameters, and realizing pre-fracturing of the top plate of the stope face before mining.
In addition, in the embodiment, the effect analysis is performed on the microseismic monitoring data before and after the fracturing method is adopted in the stoping period of the stoping working face with a large dip angle of a certain mine.
(1) Through the step S1 of this embodiment, the pressure relief rank region of the mine stope face is determined;
(2) As shown in fig. 5, in step S2 of this embodiment, medium sandstone with a thickness of 16.10m and siltstone with a thickness of 9.48m are determined as blasting fracturing target layers on the stope face;
(3) As shown in fig. 6, in step S3 of this embodiment, the elastic energy distribution characteristics of the roof of the stope face are calculated, and the target area of the blasting target horizon is determined;
(4) As shown in fig. 7, in step S4 of this embodiment, a deep hole blasting fracturing scheme of the roof of the mine stope face is formulated;
(5) As shown in fig. 8, microseismic monitoring data shows that microseismic energy of the mining working face with a large dip angle is respectively reduced by 33.8%, 1.6% and 18.5% before, during and after pressure relief; the microseismic frequency is respectively reduced by 20.4%, 19.7% and 42.5%. The monitoring data show that the pressure relief effect is obvious, and the impact risk of the large-dip angle stope face is effectively reduced.
Example two
Fig. 9 is a schematic structural diagram of a system for deep hole blasting fracturing of a top plate of a large-inclination stope face, which comprises: the device comprises a dividing module, an acquisition module, a calculation module, a positioning module and an implementation module.
The division module is used for dividing the pressure relief grade area of the stoping roadway according to the stoping direction of the stoping working face with a large inclination angle, and the working flow comprises: establishing an equation
K＝kZ＝k 1 k 2 k 3 k 4 k 5 ηH
Wherein K represents the stress load value of surrounding rock of the stoping roadway; k represents the stress concentration coefficient of the stope; z represents the original stress value of the stope; h represents the thickness of the overburden; η represents the volume weight of the overburden; k (k) 1 The stress concentration coefficient in the range of 30m near the fold structure is represented, the value is 1.2 when the fold structure exists in the stoping roadway area, and the value is 1.0 when the fold structure does not exist in the stoping roadway area; k (k) 2 Representing stress concentration coefficients in a range of 30m near the fault structure, wherein the value of the stress concentration coefficient is 1.2 when the fault structure exists in the stoping roadway area, and the value of the stress concentration coefficient is 1.0 when the fault structure exists in the stoping roadway area; k (k) 3 The centralized coefficient of the fixed supporting pressure in the coal body around the roadway is represented, the value is 1.2 when the stoping roadway is a temporary-empty roadway, and the value is 1.0 when the stoping roadway is a solid coal roadway; k (k) 4 The internal stress concentration coefficient within the range of 100m of the working face 'square' area is represented, the value is 1.2 when the working face 'square' exists in the stoping roadway area, and the value is 1.0 when the working face 'square' exists in the stoping roadway area; k (k) 5 The internal stress concentration coefficient within the range of 20m of the working face period pressing area is represented, the value is 1.2 when the working face period pressing is carried out in the stoping roadway area, and the value is 1.0 when the working face period pressing is not carried out in the stoping roadway area.
When Z is not less than K and not more than 1.4Z, the pressure relief grade of the stoping roadway is S class;
when K is more than 1.4Z and less than or equal to 2.0Z, the pressure relief grade of the stoping roadway is SS;
and when K is more than 2.0Z, the pressure relief grade of the stoping roadway is SSS.
The acquisition module is used for acquiring characteristic parameters of the coal seam roof strata in the pressure relief grade area, determining the target blasting fracturing strata position, and the working procedure comprises the following steps:
selecting a roof drilling detection point in each pressure relief grade area;
detecting the drilling detection points of each roof to obtain detection results of the attribute and the physical and mechanical parameters of the roof strata of the coal bed;
according to the detection result, determining a blasting fracturing target horizon by adopting a formula (1) and a formula (2):
in (y) j ) n Expressed as the load of the j-th roof against the n-th roof; j, n, i are respectively represented as roof strata serial numbers; e (E) n ，t n The elastic modulus and the thickness of the n-th layer of overlying strata are respectively expressed; η (eta) n The volume weight expressed as the n-th overburden;
and (3) judging the nth layer of the overburden layer meeting the relation of the formula (2) as a blasting fracturing target layer:
(y j ) n ＜(y j-1 ) n (2)
the drilling depth of the top plate detection is 50m, and drilling holes are arranged perpendicular to the top plate of the roadway; recording rock formation lithology and thickness t1 and t2 … t of roadway roof within 50m range i 。
The calculation module is used for calculating the roof elastic energy distribution characteristics of the target blasting fracturing rock horizon, and the workflow comprises the following steps:
constructing a mechanical model function of a roof structure of the large-dip angle stope face;
constructing a bending moment function at any point x of the top plate of the large-dip angle stope face according to the mechanical model function;
based on the relation between the elastic energy of the top plate and the bending moment, constructing an elastic energy calculation formula at any point x of the top plate of the large-inclination stope face;
and obtaining the elasticity distribution characteristics of the roof based on the mechanical parameter detection result and the elasticity calculation formula of the roof strata of the coal seam, and determining the fracturing area of the target fracturing strata.
The construction of the mechanical model function of the roof structure of the large-dip angle stope face is as follows:
F＝F 1 +F 2 +F 3 (3)
F 3 ＝F d (x)＝-{ρg(λsinα+cosα)·[H 0 +(L+D L -x)sinα]}(D 1 +D L ≤x≤D) (6)
wherein F is 1 Represented as a linear load exerted by the roof strata in the plastic region of the recovery roadway; f (F) 2 Expressed as linear load applied to the roof strata after goaf gangue filling; f (F) 3 Represented as a stress load exerted by the roof strata in the direction of the inclination of the coal seam;
wherein P is x The lateral restraining force of the coal wall is represented by m, and the vertical height of the coal pillar of the working surface section is represented by m; c is expressed as cohesion between coal and rock; λ is expressed as the lateral stress coefficient;
expressed as the friction angle between the coal seam and the roof strata; d (D) L Expressed as the width of the plastic zone of the stope; [ delta ] y ，max]Expressed as a stope side support pressure peak; d (D) 1 Expressed as goaf gangue filling area width; d is expressed as the working surface incline length; f (F) d (0) Represented as the load of the overburden on the suspended ceiling at the origin; ρ is represented as the average density of the overburden; g is expressed as gravitational acceleration; alpha is expressed as the stope face inclination; h 0 Expressed as the boundary burial depth on the stope face. />
The positioning module is used for formulating the roof blasting fracturing parameters of the pressure relief grade area based on the elastic energy distribution characteristics, and the working flow comprises:
when the pressure relief grade of the stope is S type: the deep hole blast holes of the top plate are arranged in three holes, the single hole explosive loading amount is 60kg, the depth of the blast holes is the target area of a fracturing target rock stratum, the blast holes are arranged in a group at intervals of 30m along the stoping direction of the working face, the blasting Kong Angjiao and the top plate of the roadway are respectively arranged at 50-70 degrees and-10-30 degrees, and the deflection angle of the blast holes and the stoping direction of the working face are arranged at 60-90 degrees;
when the pressure relief grade of the stope is SS: the deep hole blast holes of the top plate are arranged in three holes, the single hole explosive loading amount is 60kg, the depth of the blast holes is the target area of a fracturing target rock stratum, the blast holes are arranged in a group at intervals of 20m along the stoping direction of the working face, the blasting Kong Angjiao and the top plate of the roadway are respectively arranged at 50-70 degrees and-10-30 degrees, and the deflection angle of the blast holes and the stoping direction of the working face are arranged at 60-90 degrees;
when the relief grade of the stope is SSS type: the deep hole blast holes of the top plate are arranged in three holes, the single hole explosive loading amount is 60kg, the depth of the blast holes is the target area of a fracturing target rock stratum, the blast holes are arranged in a group at intervals of 10m along the stoping direction of a working face, the blasting Kong Angjiao and the top plate of the roadway are respectively arranged at 50-70 degrees and-10-30 degrees, and the deflection angle of the blast holes and the stoping direction of the working face are arranged at 60-90 degrees.
And the implementation module is used for implementing the deep hole blasting fracturing method of the top plate of the large-dip angle stope face according to the top plate blasting fracturing parameters so as to realize pre-fracturing of the top plate of the stope face before mining.
The foregoing embodiments are merely illustrative of the preferred embodiments of the present application and are not intended to limit the scope of the present application, and various modifications and improvements made by those skilled in the art to the technical solutions of the present application should fall within the protection scope defined by the claims of the present application.
Claims (4)
1. A deep hole blasting fracturing method of a top plate of a large-dip angle stope face is characterized by comprising the following steps of:
dividing a pressure relief grade area of a stoping roadway according to the stoping direction of the stoping working face with a large inclination angle;
collecting characteristic parameters of a roof stratum of the coal seam in the pressure relief grade area, and determining a target blasting fracturing stratum position;
calculating the roof elastic energy distribution characteristics of the target blasting fracturing rock horizon;
based on the elastic energy distribution characteristics, setting a roof blasting fracturing parameter of the pressure relief grade area;
according to the roof blasting fracturing parameters, implementing a deep hole blasting fracturing method of the roof of the large-dip angle stope face to realize the pre-fracturing of the roof of the stope face before mining;
the method for dividing the pressure relief grade area comprises the following steps:
2. The method of deep hole blasting fracturing of a roof of a high dip stope face of claim 1, wherein the method of determining the target blasted-fractured formation location comprises:
selecting a roof drilling detection point in each pressure relief grade area;
detecting the drilling detection points of each roof to obtain detection results of the attribute and the physical and mechanical parameters of the roof strata of the coal bed;
according to the detection result, determining a blasting fracturing target horizon by adopting a formula (1) and a formula (2):
in (y) j ) n Denoted as the firstjLayer top plate is opposite tonLoad of the layer top plate;j，n，irespectively denoted as roof formation sequence numbers;E n ，t n respectively denoted as the firstnElastic modulus and thickness of the overburden rock;η n denoted as the firstnThe volume weight of the overburden rock;
for the first relation satisfying formula (2)nThe overburden layer is a target layer judged to be burst fracturing:
3. the deep hole blasting fracturing method of the top plate of the large-dip angle stope face according to claim 1, wherein,
the method for calculating the roof elastic energy distribution characteristics of the target blasting fracturing rock horizon comprises the following steps:
constructing a mechanical model function of a roof structure of the large-dip angle stope face;
constructing any point of the top plate of the large-dip angle stope face according to the mechanical model functionxA bending moment function at;
based on the relation between the elastic energy of the top plate and the bending moment, constructing an elastic energy calculation formula at any point x of the top plate of the large-inclination stope face;
and obtaining the elasticity distribution characteristics of the roof based on the mechanical parameter detection result and the elasticity calculation formula of the roof strata of the coal seam, and determining the fracturing area of the target fracturing strata.
4. The utility model provides a deep hole blasting of big inclination stope face roof splits system, its characterized in that includes: the device comprises a dividing module, an acquisition module, a calculation module, a positioning module and an implementation module;
the dividing module is used for dividing the pressure relief grade area of the stoping roadway according to the stoping direction of the stoping working face with the large inclination angle;
the acquisition module is used for acquiring characteristic parameters of the coal seam roof strata in the pressure relief grade area and determining a target blasting fracturing strata position;
the calculation module is used for calculating the roof elastic energy distribution characteristics of the target blasting fracturing rock horizon;
the positioning module is used for formulating a roof blasting fracturing parameter of the pressure relief grade area based on the elastic energy distribution characteristics;
the implementation module is used for implementing a deep hole blasting fracturing method of the top plate of the large-dip angle stope face according to the top plate blasting fracturing parameters so as to realize pre-fracturing of the top plate of the stope face before mining;
the dividing module is used for dividing the pressure relief grade area of the stoping roadway according to the stoping direction of the stoping working face with a large inclination angle, and the working flow comprises: establishing an equation
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