CN109635357B - Overburden bed separation dynamic position prediction method considering mining rock mass crushing expansion - Google Patents
Overburden bed separation dynamic position prediction method considering mining rock mass crushing expansion Download PDFInfo
- Publication number
- CN109635357B CN109635357B CN201811383165.6A CN201811383165A CN109635357B CN 109635357 B CN109635357 B CN 109635357B CN 201811383165 A CN201811383165 A CN 201811383165A CN 109635357 B CN109635357 B CN 109635357B
- Authority
- CN
- China
- Prior art keywords
- rock
- separation layer
- layer
- stratum
- group
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/10—Geometric CAD
- G06F30/13—Architectural design, e.g. computer-aided architectural design [CAAD] related to design of buildings, bridges, landscapes, production plants or roads
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/20—Design optimisation, verification or simulation
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F2119/00—Details relating to the type or aim of the analysis or the optimisation
- G06F2119/06—Power analysis or power optimisation
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Geometry (AREA)
- Theoretical Computer Science (AREA)
- Computer Hardware Design (AREA)
- General Physics & Mathematics (AREA)
- Evolutionary Computation (AREA)
- General Engineering & Computer Science (AREA)
- Architecture (AREA)
- Civil Engineering (AREA)
- Structural Engineering (AREA)
- Computational Mathematics (AREA)
- Mathematical Analysis (AREA)
- Mathematical Optimization (AREA)
- Pure & Applied Mathematics (AREA)
- Investigation Of Foundation Soil And Reinforcement Of Foundation Soil By Compacting Or Drainage (AREA)
Abstract
The invention discloses a dynamic position prediction method of a overburden abscission layer considering the crushing and swelling property of a mined rock mass, wherein the differences of abscission layer mechanical models of different layers caused by the crushing and swelling property of the rock mass are considered, and for an abscission layer below the maximum development height of an caving zone, upper and lower rock groups of the abscission layer are simplified into two-end fixed beam models for analysis and calculation; for the separation layer above the maximum development height of the caving zone, the upper rock group of the separation layer is simplified into the fixed supporting beams at two ends, and the lower rock group of the separation layer is simplified into the elastic Weckel foundation beam for analysis and calculation, so that compared with the traditional method, the mechanical model selected by the method is more reasonable; the invention also provides the criterion for disappearance of the separation layers of different layers, and can be used for predicting the dynamic development position of the roof separation layer, so that the development position of the overlying strata separation layer corresponding to the footage of the working face can be more accurately predicted, and the basic research and control work of rock stratum movement and related secondary disasters can be better served.
Description
Technical Field
The invention relates to a method for predicting a delamination development position, in particular to a method for predicting a dynamic position of a overburden delamination in consideration of the breaking and swelling property of a mined rock mass, and belongs to the technical field of underground safe production.
Background
A goaf can be formed after the coal seam is mined, and the original stress of the overlying rock-soil layer of the goaf can be redistributed in the coal seam mining process, so that deformation and damage with a certain rule are generated. According to the damage degree of the rock-soil body after coal seam mining, the overlying rock-soil layer after mining can be divided into from top to bottom: bending subsidence zones, crack zones and caving zones, i.e. caving zones. The coal seam overlying rock-soil layer is subjected to abscission and falling from the direct top rock layer due to mining unbalance, and gradually develops upwards until the space for mining the coal seam is filled with fallen broken rock-soil bodies, and the part is called a falling zone. During the formation of the caving zone, the rock stratum caving from the roof separation layer is not limited by the broken and expanded rock mass in the goaf in the downward migration process; and the separation layer positioned in the upper fracture zone or the bending subsidence zone of the caving zone cannot be supported and limited by the broken expansive rock body in the bending downward moving process of the rock stratum at the lower part of the caving zone because the goaf is filled, and the separation layer mechanical model and the separation layer disappearance mode are different from those of the separation layer in the caving zone.
At present, the traditional method for predicting the position of the delamination development is based on a combination beam theory, and judges whether the contact surface of the adjacent rock stratum is pulled away to generate the delamination or not by comparing the bending resistance of the adjacent rock stratum. The specific judgment method is as follows:
a combination beam composed of n strata is arranged above the goaf, and the thickness, the gravity and the elastic modulus of each stratum are respectively h i 、γ i 、E i (i =1,2,3 \ 8230n); based on the composite beam principle, the load (q) actually born by the bottommost rock stratum (namely the 1 st layer of the composite beam) is calculated n ) 1 ，
If (q) n+1 ) 1 ＜(q n ) 1 And judging that separation layers are generated between the n +1 th layer and the n-th layer.
The traditional judging method or the deformation method thereof is widely applied to basic research and prevention and control work of rock stratum movement and related secondary disasters, such as bed separation water damage, rock burst, collapse accidents of coal mine roofs and the like. However, the conventional theoretical method has many disadvantages, such as: (1) The method is characterized in that a 'combination beam' formed by rock strata is not supported by a lower broken rock body in the process of transporting the combination beam to the goaf by default, namely, the difference of separation mechanical models of different strata caused by rock mass breaking expansibility is not considered. (2) The roof overlying strata movement mode is bending deformation damage by taking a rock stratum group consisting of single-layer or multi-layer rock stratum as a unit, and separation layers can only be generated on the contact surface of the adjacent rock stratum group; in the method, each layer of overlying rock of the top plate is independently used as a comparison object of mechanical properties, so that the prediction result has more deviation undoubtedly. (3) With coal seam mining, the roof separation layer presents an evolution process of transverse spreading and longitudinal dynamic jump, the method does not consider the influence of working face footage on the stability of the roof overlying strata separation layer, the closing or disappearance of the separation layer cannot be predicted, and the dynamic position change of the roof overlying strata separation layer development cannot be predicted. Therefore, the traditional prediction method cannot accurately predict the bed separation dynamic development position, namely the roof overlying strata bed separation development position corresponding to a certain scale of the working face cannot be predicted.
Disclosure of Invention
In order to overcome various defects in the prior art, the invention provides a method for predicting the dynamic position of a overburden bed separation in consideration of the crushing and swelling property of a mining rock mass, the difference of internal and external bed separation mechanical models of an caving zone is fully considered, and the development position of the overburden bed separation corresponding to the footage of a working face is more accurately predicted so as to better serve the basic research and prevention and control work of rock stratum movement and related secondary disasters.
In order to achieve the aim, the invention provides a method for predicting the dynamic position of a overburden separation layer by considering the crushing and swelling property of a mining rock mass, which is characterized by comprising the following steps of:
step one, determining the range of a developable separation layer according to the footage of a working face and a rock stratum breaking angle circle;
secondly, carrying out rock stratum combination division on the overburden rock in the range of the developable separation layer according to the thickness, the elastic modulus and the volume weight of the rock stratum based on a combination beam principle, judging the position of the developable separation layer, and determining the length of the developable separation layer;
thirdly, based on mining area mining practice summary experience or coal mine water prevention and control regulations, predicting the maximum development height of the caving zone according to the actual mining working condition and the stratum structure of the working face;
fourthly, judging whether the separation layer in the maximum development height of the caving zone is unstable and broken or not according to the judgment result of the second step and the maximum expected height of the caving zone and the tensile strength of the rock stratum determined in the third step, and further judging the stable separation layer position within the maximum development height of the caving zone;
and fifthly, determining whether the producible abscission layer above the maximum development height of the caving zone is unstable, broken or closed or not according to the thickness of the coal layer mined on the working face, the rock mass crushing and swelling coefficient, the judgment result of the second step, the maximum expected height of the caving zone and the tensile strength of the rock stratum in the third step, and further judging the stable abscission layer position above the maximum caving zone height.
Specifically, in the first step, the abscission layer development range is a triangle defined by the front and rear breaking lines of the overburden rock and the footage of the working face, and the calculation formula of the abscission layer development range height is as follows:
in the formula: h is the height of the abscission layer development range, and the unit is m; l is the working face footage and the unit is m; alpha (alpha) ("alpha") 1 、α 2 The front and rear breaking angles of the rock stratum.
Specifically, the specific steps of determining the length of the viable delamination in the second step are as follows:
(1) numbering 1,2, a. Calculating the actual bearing load (q) of the lowest stratum, namely the 1 st stratum of the composite beam when the n strata synchronously deform in the form of the composite beam n ) 1 ；
In the formula: e i The lithological modulus of the ith stratum is expressed in MPa; h is i The thickness of the ith layer rock stratum is m; gamma ray i Is the weight of the ith rock layer and has the unit of kN/m 3 ；
(2) If the calculation result of the step (1) meets (q) m ) 1 ＝max((q 1 ) 1 ,(q 2 ) 1 ,…,(q n ) 1 ) And 1 is less than or equal to m<n, judging that separation occurs between the (m + 1) th rock stratum and the mth rock stratum, and dividing the 1-m rock strata into the same rock stratum group with the number of #1;
(3) taking the (m + 1) th rock stratum as a first layer of the composite beam, numbering the rock strata above the (m) layers from bottom to top in sequence, repeating the steps (1) and (2), numbering rock stratum groups from bottom to top in sequence as #1, #2, # n, and taking the contact surface between the rock stratum groups as the position of abscission development;
(4) step (1)The calculation result of (3) satisfies (q) n ) 1 ＝max((q 1 ) 1 ,(q 2 ) 1 ,…,(q n ) 1 ) Judging that no separation layer is generated from the rock stratum 1 to the rock stratum n, and dividing the rock stratum 1 to the rock stratum n into the same rock stratum group;
(5) according to the formula L = L-H s (cotα 1 +cotα 2 ) Calculating the delamination length of each of the cultivations, wherein: l is the length of the growing delamination layer in m; l is the working face footage, and the unit is m; h s The distance between a position capable of growing and a coal seam, namely the height of the growing off-seam, is m; alpha (alpha) ("alpha") 1 、α 2 The front and rear breaking angles of the rock stratum are shown.
Specifically, in the fourth step, the stable separation layer position within the maximum falling zone height is further judged, and the specific steps are as follows:
(1) for the developed abscission layer in the maximum development height of the false fall zone, according to the formula
Respectively calculating the breaking distance l of the upper and lower rock stratum groups of the separation layer On the upper part And l Lower part In the formula: l i The breaking distance of the rock group numbered # i is in the unit of m; h is i The thickness of the rock group numbered # i in m; sigma i Tensile strength in MPa for the rock group number # i; q. q of i The self weight of the rock group with the number # i is N/m 2 ；
(2) Comparing the size of the exploratory distance of the upper and lower rock groups of the separation layer with the size of the exploratory distance of the separation layer: if l<min(l Upper part of ，l Lower part ) Judging that the separation layer is not instable, namely the separation layer is a stable separation layer; if l is not less than min (l) On the upper part ，l Lower part ) And judging that the separation layer is instable and broken, and the separation layer disappears.
Specifically, in the fifth step, the stable separation layer position above the maximum falling zone height is further judged, and the specific steps are as follows:
(1) for the developed abscission layer above the maximum development height of the falling zone, according to the formula
Calculating the fracture distance l of the upper strata group in the separation layer Upper part of (ii) a In the formula: l i The breaking distance of the serial number # i rock group is m; h is a total of i The thickness of the rock group numbered # i in m; sigma i Tensile strength in MPa for the rock group number # i; q. q of i The self weight of the rock group with the number # i is N/m 2 ；
(2) According to the following bending moment function M max (l) And extreme bending moment [ M ]]Formula, calculate M max ＝[M]Breaking distance l of time-separation layer lower rock group Lower part ；
Wherein:
in the formula: k is a foundation coefficient and has a unit of kN/m 3 (ii) a q is the dead weight of the rock set and the unit is N/m 2 (ii) a EI is the flexural rigidity of the rock group, in N.m 2 (ii) a Beta is a characteristic coefficient, and 1/m is taken; h is i Is the thickness of the ith layer of rock mass in m;
and
are all kresof functions;
(3) according to the following delamination amount function h s (l) Calculating the delamination volume h s (l) Transverse delaminating dimension l capable of growing when =0 s ；
Wherein:
in the formula: delta of i The free space at the lower part of the ith rock group is m; m is the thickness of the mined coal bed and is M; h is j Is the thickness of the jth layer of rock mass in m; lambda j The coefficient of crushing and expansion of the jth rock group is zero dimension; q. q of On the upper part 、q Lower part Is the dead weight of the rock group at the upper and lower positions and has the unit of N/m 2 ；E On the upper part I On the upper part Is the bending rigidity of the superordinate rock group and has the unit of N.m 2 ；
(4) Comparing l, l On the upper part 、l Lower part And l s The size of (2): if l<min(l On the upper part ，l Lower part ，l s ) Judging that the separation layer is not unstable or closed, namely the separation layer is a stable separation layer; if l is not less than min (l) On the upper part ，l Lower part ，l s ) And judging that the separation layer is instable or closed, namely the separation layer disappears.
The invention fully considers the difference of the mechanics models of the separation layers of different layers caused by the rock mass crushing and expanding property, and simplifies the upper and lower rock groups of the separation layers into the fixed beam models at the two ends for analysis and calculation for the separation layers below the maximum development height of the caving zone; for the separation layer above the maximum development height of the caving zone, the upper rock group of the separation layer is simplified into the fixed-support beams at two ends, and the lower rock group of the separation layer is simplified into the elastic Weckel foundation beam for analysis and calculation, so that compared with the traditional method, the mechanical model selected by the method is more reasonable; the invention also provides a criterion for disappearance of the separation layers of different layers, and can be used for predicting the dynamic development position of the roof separation layer. The method has simple steps, the selected mechanical model and the judgment criterion are more in line with the actual stope, the defects of the traditional judgment criterion are overcome, the prediction result is more accurate, the method is convenient to popularize, and the method can better serve basic research and prevention and treatment work of rock stratum movement and related secondary disasters.
Drawings
FIG. 1 is a flow chart of a method embodying the present invention;
FIG. 2 shows the TV imaging results of the holes drilled on the 745 working face of an east mine
Detailed Description
The invention is described in detail below with reference to the figures and the specific embodiments.
The buried depth of a coal bed of a working face of a certain east mine 745 is 327.76-382.08M, the mining height of the coal bed is M =2.3M, the strike length is 400M, the inclination width is 60-120M, the coal bed of a working face roof mainly comprises sandstone and mudstone, hard and thick mudstone exists at a high position, and specific stratum occurrence conditions and physical and mechanical parameters are shown in table 1. The working face adopts a single longwall caving coal mining method, and separation water inrush occurs when the stoping trend is about L =150 m.
The method provided by the invention is used for predicting the 745 working surface abscission layer development condition when the footage reaches 150m, and as shown in figure 1, the method comprises the following specific steps:
firstly, determining the development range of an isolated layer according to the footage of a working face and the broken angle circle of a rock stratum:
the working face footage L is 150m, and the front and back break angles alpha of the rock stratum 1 、α 2 Taking 62 degrees of separation development range as a triangle defined by the front and back breaking lines of the overburden rock and the footage of the working face according to a formula
Calculating the height H of a delamination development range to be 141m;
step two, according to the stratum thickness in the table 1, the rock stratum entering the height of the separation development range is No. 1-6 rock stratum; based on a composite beam principle, preliminarily distinguishing the position of the exploitable bed separation of the overlying strata in the bed separation development range according to the thickness, the elastic modulus and the volume weight of the stratum separation, and calculating the length of the bed separation, wherein the specific method comprises the following steps:
(1) numbering 1,2, a. Calculating the actual bearing load (q) of the lowest stratum, namely the 1 st stratum of the composite beam when the n strata synchronously deform in the form of the composite beam n ) 1 ；
In the formula: e i The lithological modulus of the ith rock stratum is in MPa; h is i The thickness of the ith layer rock stratum is m; gamma ray i Is the weight of the ith rock layer and has the unit of kN/m 3 ；
(2) If the calculation result of the step (1) meets (q) m ) 1 ＝max((q 1 ) 1 ,(q 2 ) 1 ,…,(q n ) 1 ) And 1 is less than or equal to m<n, judging that separation occurs between the (m + 1) th rock stratum and the mth rock stratum, and dividing the 1-m rock strata into the same rock stratum group with the number of #1;
(3) taking the (m + 1) th rock stratum as the first layer of the composite beam, numbering the rock strata above the m layers from bottom to top in sequence, repeating the steps (1) and (2), numbering rock stratum groups from bottom to top in sequence as #1, #2, # and # n, wherein the contact surface between the rock stratum groups is the position of the separation development;
(4) if the calculation result of the step (1) or (3) satisfies (q) n ) 1 ＝max((q 1 ) 1 ,(q 2 ) 1 ,…,(q n ) 1 ) Judging that no separation layer is generated from the rock stratum 1 to the rock stratum n, and dividing the rock stratum 1 to the rock stratum n into the same rock stratum group;
(5) according to the formula L = L-H s (cotα 1 +cotα 2 ) Calculating the delamination length of each of the cultivations, wherein: l is the length of the growing delamination layer in m; l is the working face footage and the unit is m; h s The distance between a position capable of growing and a coal seam, namely the height of the growing off-seam, is m; alpha (alpha) ("alpha") 1 、α 2 The front and rear breaking angles of the rock stratum.
As shown in table 1, the physical and mechanical parameters provided by geological data and the data calculated by analysis are used to obtain the primary discrimination result of the 745 working face roof overburden separation layer.
TABLE 1
Thirdly, the maximum development height of the caving zone is 6.9m based on the practical summary experience of mining in the mining area;
fourthly, directly judging the stability of the separation layer outside the height of the falling zone because the maximum development height of the falling zone is not provided with the separation layer, and the specific method is as follows:
(1) and for the developed abscission layer outside the maximum development height of the falling zone, according to the formula
Calculating the fracture distance l of the upper strata group in the separation layer On the upper part ；
(2) According to the following bending moment function M max (l) And extreme bending moment [ M ]]Formula, calculate M max ＝[M]Breaking distance l of time-separation layer lower rock group Lower part ；
Wherein:
in the formula: k is a foundation coefficient and has a unit of kN/m 3 (ii) a q is the dead weight of the rock set and the unit is N/m 2 (ii) a EI is the flexural rigidity of the rock group, in N.m 2 (ii) a Beta is a characteristic coefficient, 1/m; h is i Is the thickness of the ith layer of rock mass in m;
and
are all kresof functions;
(3) according to the following delamination amount function h s (l) Calculating the delamination volume h s (l) Delamination transverse dimension l at =0 s ；
Wherein:
in the formula: delta i The free space at the lower part of the ith rock group is m; m is the thickness of the mined coal bed and is M; h is a total of j Is the thickness of the jth layer of rock group in m; lambda j The coefficient of crushing and expansion of the jth rock group is zero dimension; q. q.s Upper part of 、q Lower part Is the dead weight of the rock group at the upper and lower positions and has the unit of N/m 2 ；E On the upper part I On the upper part Is the bending rigidity of the superordinate rock group and has the unit of N.m 2 ；
(4) Comparing l, l Upper part of 、l Lower part And l s The size of (2): if l<min(l On the upper part ，l Lower part ，l s ) Judging that the separation layer is not unstable or closed, namely the separation layer exists; if l is not less than min (l) On the upper part ，l Lower part ，l s ) And judging that the separation layer is instable or closed, namely the separation layer disappears.
According to geological data of a mining area, taking a foundation coefficient k as 100MN/m 3 And the coefficient of crushing expansion is 1.3, firstly, the stability of the separation layer between the rock strata with the numbers of 1 and 2 is judged, and the data is substituted into the calculation l On the upper part ，l Lower part ，l s The result shows min (l) On the upper part ，l Lower part ，l s )＝107.38m<125.40m, where the delamination is unstable; similarly, the stability of the separation layer between the rock layers with the numbers 5 and 6 is judged, and the calculation result shows that min (l) On the upper part ，l Lower part ，l s )<84.92m, namely judging that the separation layer is broken and unstable.
In order to verify the accuracy of the prediction method, the 745 working surface is subjected to delamination and fissure zone detection by a drilling television imaging method through ground drilling so as to find out the layer position of the delamination, and after the hole is drilled into the coal-based stratum by 31.47 meters, the hole bottom is drilled after the residual delamination is seen. According to the imaging result of a borehole television (shown in figure 2), a residual separation layer is found at the position with the burial depth of 316.83m (the contact surface of the rock magma with the number 5 and the number 6), and the separation layer is broken and unstable, so that the accuracy of the prediction method is verified.
Claims (4)
1. A method for predicting the dynamic position of a overburden separation layer by considering the breaking swelling property of a mined rock mass is characterized by comprising the following steps:
step one, determining the range of a developable separation layer according to the footage of a working face and a rock stratum breaking angle circle;
secondly, carrying out rock stratum combination division on the overburden rock within the range of the exploitable separation layer according to the thickness of the rock stratum, the elastic modulus and the volume weight based on the principle of a combination beam, judging the position of the exploitable separation layer and determining the length of the exploitable separation layer;
thirdly, based on the practical summary experience of mining area mining or the stipulation of coal mine water control, estimating the maximum development height of the caving zone according to the actual mining working condition of the working face and the stratum structure;
fourthly, judging whether the separation layer in the maximum development height of the caving zone is unstable and broken or not according to the judgment result of the second step and the maximum predicted height of the caving zone and the tensile strength of the rock stratum determined in the third step, and further judging the stable separation layer position within the maximum development height of the caving zone;
fifthly, determining whether the developed separation layer above the maximum development height of the caving zone is unstable and broken or closed or not according to the thickness of the coal seam mined on the working face, the rock mass crushing and expansion coefficient, the judgment result of the second step, the maximum expected height of the caving zone in the third step and the tensile strength of the rock stratum, and further judging the stable separation layer position above the maximum caving zone height, wherein the specific steps are as follows:
(1) for the developed abscission layer above the maximum development height of the falling zone, according to the formula
Calculating the fracture distance l of the upper strata group in the separation layer On the upper part (ii) a In the formula: l i The breaking distance of the serial number # i rock group is m; h is i The thickness of the rock group numbered # i in m; sigma i Tensile strength in MPa for the rock group number # i; q. q.s i The dead weight of the rock group with the number # i is N/m 2 ；
(2) According to the following bending moment function M max (l) And extreme bending moment [ M ]]Formula, calculate M max ＝[M]Breaking distance l of time-separation layer lower rock group Lower part ；
Wherein:
in the formula: k is a foundation coefficient and has a unit of kN/m 3 (ii) a q is the dead weight of the rock set and the unit is N/m 2 (ii) a EI is the flexural rigidity of the rock group, in N.m 2 (ii) a Beta is a characteristic coefficient, and 1/m is taken; h is a total of i Is the thickness of the ith layer of rock mass in m;
and
are all kresof functions;
(3) according to the following delamination amount function h s (l) Calculating the delamination volume h s (l) When =0, can developTransverse dimension of delamination l s ；
Wherein:
in the formula: delta of i The free space at the lower part of the ith rock group is m; m is the thickness of the mined coal bed and is M; h is a total of j Is the thickness of the jth layer of rock mass in m; lambda j The coefficient of crushing and expansion of the jth rock group is zero dimension; q. q of Upper part of 、q Lower part Is the dead weight of the upper and lower rock groups and the unit is N/m 2 ；E Upper part of I Upper part of Is the bending rigidity of the superordinate rock group and has the unit of N.m 2 ；
(4) And comparing l and l Upper part of 、l Lower part And l s The size of (c): if l < min (l) Upper part of ，l Lower part ，l s ) Judging that the separation layer is not unstable or closed, namely the separation layer is a stable separation layer; if l is not less than min (l) Upper part of ，l Lower part ，l s ) And judging that the separation layer is instable or closed, namely the separation layer disappears.
2. The method for predicting the dynamic position of the overburden separation layer considering the crushing expansion property of the mining rock body as claimed in claim 1, wherein in the first step, the separation layer development range is a triangle defined by a breaking line before and after the overburden and a working face footage, and the calculation formula of the height of the separation layer development range is as follows:
in the formula: h is the height of the abscission layer development range, and the unit is m; l is the working face footage, and the unit is m; alpha is alpha 1 、α 2 The front and rear breaking angles of the rock stratum are shown.
3. The method for predicting the dynamic position of the overburden separation layer by considering the crushing and swelling property of the mined rock mass according to claim 2, wherein the specific steps of determining the length of the developed separation layer in the second step are as follows:
(1) numbering 1,2, a. Calculating the actual bearing load (q) of the lowest stratum, namely the 1 st stratum of the composite beam when the n strata synchronously deform in the form of the composite beam n ) 1 ；
In the formula: e i The lithological modulus of the ith rock stratum is in MPa; h is i The thickness of the ith layer rock stratum is m; gamma ray i Is the weight of the ith rock layer and has the unit of kN/m 3 ；
(2) If the calculation result of the step (1) meets (q) m ) 1 ＝max((q 1 ) 1 ，(q 2 ) 1 ，...，(q n ) 1 ) And m is more than or equal to 1 and less than n, the fact that separation occurs between the (m + 1) th rock stratum and the mth rock stratum is judged, and then the 1-m rock strata are divided into the same rock stratum group which is numbered as #1;
(3) taking the (m + 1) th rock stratum as the first layer of the composite beam, numbering the rock strata above the m layers from bottom to top in sequence, repeating the steps (1) and (2), numbering rock stratum groups from bottom to top in sequence as #1, #2, # and # n, wherein the contact surface between the rock stratum groups is the position of the separation development;
(4) if the calculation result of the step (1) or (3) satisfies (q) n ) 1 ＝max((q 1 ) 1 ，(q 2 ) 1 ，...，(q n ) 1 ) Judging that no separation layer is generated between the No. 1 rock stratum and the No. n rock stratum, and dividing the 1-n rock strata into the same rock stratum group;
(5) according to the formula L = L-H s (cotα 1 +cotα 2 ) Calculating the length of each growing delamination layer, wherein: l is the length of the growing delamination, in m; l is the working face footage inm；H s The distance between the position of the producible off-bed and the coal bed, namely the height of the producible off-bed, and the unit is m; alpha is alpha 1 、α 2 The front and rear breaking angles of the rock stratum.
4. The method for predicting the dynamic position of the overburden separation layer considering the crushing and swelling property of the mined rock mass according to claim 3, wherein in the fourth step, the stable separation layer position within the maximum caving zone height is further judged, and the specific steps are as follows:
(1) for the development of the separating layer within the maximum development height of the falling zone, according to the formula
Respectively calculating the breaking distance l of the upper and lower rock stratum groups of the separation layer Upper part of And l Lower part In the formula: l. the i The breaking distance of the rock group numbered # i is in the unit of m; h is a total of i The thickness of the rock group numbered # i in m; sigma i Tensile strength in MPa for the rock group number # i; q. q of i The self weight of the rock group with the number # i is N/m 2 ；
(2) Comparing the producible separation length l with the breaking distance of the upper and lower rock groups of the separation: if l < min (l) On the upper part ，l Lower part ) Judging that the separation layer is not unstable, namely the separation layer is a stable separation layer; if l is not less than min (l) Upper part of ，l Lower part ) Then, the separation layer is judged to be unstable, and the separation layer is broken and disappears.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811383165.6A CN109635357B (en) | 2018-11-20 | 2018-11-20 | Overburden bed separation dynamic position prediction method considering mining rock mass crushing expansion |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811383165.6A CN109635357B (en) | 2018-11-20 | 2018-11-20 | Overburden bed separation dynamic position prediction method considering mining rock mass crushing expansion |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109635357A CN109635357A (en) | 2019-04-16 |
| CN109635357B true CN109635357B (en) | 2023-03-14 |
Family
ID=66068509
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201811383165.6A Active CN109635357B (en) | 2018-11-20 | 2018-11-20 | Overburden bed separation dynamic position prediction method considering mining rock mass crushing expansion |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109635357B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113916590B (en) * | 2021-10-13 | 2023-08-15 | 中煤地质集团有限公司 | Accurate detection method for overlying strata separation layer |
| CN115977635B (en) * | 2023-03-17 | 2023-05-30 | 中国矿业大学(北京) | Goaf caving gangue crushing expansion coefficient testing method and system |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108805352A (en) * | 2018-06-08 | 2018-11-13 | 中国矿业大学 | A kind of exploiting field overlying strata separation layer water water damage hazard assessment method |
-
2018
- 2018-11-20 CN CN201811383165.6A patent/CN109635357B/en active Active
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108805352A (en) * | 2018-06-08 | 2018-11-13 | 中国矿业大学 | A kind of exploiting field overlying strata separation layer water water damage hazard assessment method |
Non-Patent Citations (3)
| Title |
|---|
| Investigation on mining-induced fractured zone height developed in different layers above Jurassic coal seam in western China;Shiliang Liu等;《Arabian Journal of Geosciences》;20180111;第1-10页 * |
| 注浆过程中离层位置的判定研究;郝延锦等;《煤》;20001231;第9卷(第1期);第33-34,44页 * |
| 考虑岩体碎胀效应的采场覆岩冒落规律分析;李连崇等;《岩土力学》;20101130;第31卷(第11期);第3537-3541页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109635357A (en) | 2019-04-16 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110778316B (en) | Sublevel rock drilling stage open stope subsequent filling mining method adopting arched-arch-shaped top pillar structure | |
| WO2019233114A1 (en) | Method for evaluating risk of water damage from strata water inrush of overlying strata in mining area | |
| Bye et al. | Stability assessment and slope design at Sandsloot open pit, South Africa | |
| CN107989613A (en) | A kind of overlying strata separation layer subregion isolates grouting filling working seam complete extraction method | |
| CN110765642B (en) | Zonal evaluation method for roof rock stratum structure of coal seam, mining area or working face | |
| CN109798149B (en) | Method for predicting inflow intensity of mining field of thick coal seam with hard roof in grading manner | |
| CN109635357B (en) | Overburden bed separation dynamic position prediction method considering mining rock mass crushing expansion | |
| CN114519257A (en) | Surface subsidence type prediction method | |
| CN116049964B (en) | Anti-impact method for artificial liberation layer of newly-built mine | |
| CN116167223B (en) | Method for determining artificial liberation layer | |
| CN115929304B (en) | Method for preventing impact of artificial relief layer of stope face | |
| CN116050171B (en) | Anti-impact method for artificial liberation layer of tunneling roadway | |
| Wang et al. | Failure mechanism of anti-inclined karst slope induced by underground multiseam mining | |
| CN116258000A (en) | Anti-impact method for artificial liberation layer | |
| CN111428357A (en) | Method for determining maximum subsidence value of earth surface based on height of overburden rock residual free space | |
| Sakhno et al. | Field investigations of deformations in soft surrounding rocks of roadway with roof-bolting support by auger mining of thin coal seams | |
| CN114329922B (en) | Method for determining height of water flowing fractured zone based on structural overlying strata | |
| CN115130051A (en) | Overburden separation layer discrimination method considering horizontal stress and mining unloading effect | |
| CN115045660A (en) | Deep hole blasting and cracking method and system for top plate of large-dip-angle stope face | |
| CN109611084B (en) | Method for judging position of water-accumulatible separation layer of mining overburden rock | |
| CN115163066A (en) | Rock burst mine roadway thick-layer bottom coal gangue inclusion blasting cracking combined pressure relief method | |
| Wu et al. | Research of the Shape of Pressure Arch in Layered Rock Mass Based on the Protodyakonov's Theory | |
| CN112861068A (en) | Method for determining mining overburden rock damage height | |
| CN114370250A (en) | Goaf disaster management method based on stratum exploration | |
| Xu et al. | Method to calculate mining-induced fracture based on the movement and deformation of overburden strata |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |