CN114673532A - Fracture zone global grouting subsidence reducing method capable of preventing top plate from permeating water - Google Patents

Fracture zone global grouting subsidence reducing method capable of preventing top plate from permeating water Download PDF

Info

Publication number
CN114673532A
CN114673532A CN202210367007.1A CN202210367007A CN114673532A CN 114673532 A CN114673532 A CN 114673532A CN 202210367007 A CN202210367007 A CN 202210367007A CN 114673532 A CN114673532 A CN 114673532A
Authority
CN
China
Prior art keywords
anchoring
grouting
layer
water
rock stratum
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.)
Pending
Application number
CN202210367007.1A
Other languages
Chinese (zh)
Inventor
林中湘
马占国
郝燕奎
龚鹏
马云靖
古傲林
姚文涛
刘国强
岳鹏
张帆
刘旺
姜涛
高芙蓉
孟凡飞
周凤羽
严鹏飞
刘子璐
陈韬
徐敏
和泽欣
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Moscow University Of Shenzhen Beili University
China University of Mining and Technology CUMT
China Coal Geology Group Co Ltd
Original Assignee
Moscow University Of Shenzhen Beili University
China University of Mining and Technology CUMT
China Coal Geology Group Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Moscow University Of Shenzhen Beili University, China University of Mining and Technology CUMT, China Coal Geology Group Co Ltd filed Critical Moscow University Of Shenzhen Beili University
Priority to CN202210367007.1A priority Critical patent/CN114673532A/en
Publication of CN114673532A publication Critical patent/CN114673532A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • E—FIXED CONSTRUCTIONS
    • E21—EARTH DRILLING; MINING
    • E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
    • E21D11/00—Lining tunnels, galleries or other underground cavities, e.g. large underground chambers; Linings therefor; Making such linings in situ, e.g. by assembling
    • E21D11/38—Waterproofing; Heat insulating; Soundproofing; Electric insulating
    • E—FIXED CONSTRUCTIONS
    • E21—EARTH DRILLING; MINING
    • E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
    • E21D20/00—Setting anchoring-bolts
    • E21D20/02—Setting anchoring-bolts with provisions for grouting

Abstract

The invention discloses a fissure zone global grouting subsidence reducing method capable of preventing a roof from permeating water, which comprises the steps of firstly drilling a plurality of anchoring vertical wells arranged in an array from the ground to a water-resisting key layer and making holes in each overlying rock layer above the water-resisting key layer to form rock layer anchoring holes before mining the mine layer according to the burying range of the mine layer to be mined, then respectively placing corresponding anchoring grouting pipes into each anchoring vertical well and then performing well cementation operation, finally injecting anchoring grout into anchoring grouting pipes in the anchoring vertical wells in a continuous pressure grouting mode before mining or in the mining process of the mine layer to be mined, anchoring the anchoring grout forms a full-length anchoring mode along the depth direction of the water-resisting key layer after being completely solidified, and all the anchoring vertical wells arranged in an array form a unit group anchoring effect on the overlying rock layer above the water-resisting key layer together, so that the damage influence of mining action of the mine layer on the water-resisting key layer can be greatly reduced, thereby realizing the maximum reduction of the probability of the water penetration accident of the top plate.

Description

Fracture zone global grouting subsidence reducing method capable of preventing top plate from permeating water
Technical Field
The invention relates to a method for preventing a coal face roof from permeating water under a coal mine, in particular to a fracture zone global grouting subsidence reducing method capable of preventing the roof from permeating water, and belongs to the technical field of mine safety.
Background
In underground mining, underground mining of mines is still the main mining mode, taking coal mining as an example, underground mining of mines accounts for 60% of coal mining production in the world. In the process of mine construction and production, artificial underground engineering inevitably causes geological conditions of surrounding rocks to change to generate geological changes such as cracks, faults, subsidence areas and the like, and surface water and underground water often enter a mine through channels such as the cracks, the faults, the subsidence areas and the like, so corresponding water prevention measures must be implemented in the process of mine construction and production, and if the surface water and the underground water flow into a mine working face in an uncontrolled manner due to the fact that the water prevention measures are not in place, flood accidents of casualties of operating personnel or mine property loss can be caused, which are also commonly called as water permeability accidents, and the water permeability accidents often take the mode of flowing into the cracks or the faults of a top plate of the mine working face.
When there are multiple layers in a stope-covered formation, the bearing capacity and permeation resistance are not the same between each layer, and the water-barrier critical layer is the portion of the formation through which water must eventually pass. Natural channels and mining fractures in geological structures are two main ways for water to break through key water-proof layers. The key to avoid the water-permeable accident is not to damage the water-proof key layer during mining and maintain the integrity of the water-proof key layer. On one hand, however, in the underground mining process of a well worker, a large area of underground goaf is often left after the mining of an underground ore bed is finished, and under the action of factors such as overburden pressure and underground water, ore columns and ore beds on two sides of a mining area are softened and lose strength, so that an overlying rock mass is prone to sinking, falling and forming a landslide, and further damage to a water-proof key layer is prone to being caused; on the other hand, in the mining process of the mine, the surrounding rock of the goaf is influenced by blasting vibration, so that the crack development of the rock mass is easy to cause to damage a water-proof key layer, and even the rock mass penetrates through the ground surface or is communicated with the accumulated water of the old kiln, thereby causing water permeation accidents.
Disclosure of Invention
Aiming at the problems in the prior art, the invention provides a fracture zone global grouting subsidence reducing method capable of preventing a roof from permeating water, which can reduce the damage to a water-proof key layer in the mining process to the maximum extent and further reduce the occurrence probability of roof water permeation accidents to the maximum extent.
In order to achieve the purpose, the fracture zone global grouting subsidence reducing method capable of preventing the top plate from permeating water specifically comprises the following steps of:
a. preparing for well construction: detecting and determining the buried depth, the thickness and the buried range of a layer to be mined, detecting and determining the number, the buried depth, the thickness and the lithology of overlying strata of the layer to be mined, determining the position and the depth of a main key layer and a water-resisting key layer, and constructing a geological mathematical model; based on a geological mathematical model, the hole diameter, the number and the array row spacing of the anchoring vertical shafts corresponding to the burying range of the mining layer and the size of the anchoring grouting pipes matched with the anchoring vertical shafts are determined according to the depth of a water-resisting key layer, the number of all overlying rock layers above the water-resisting key layer and lithology calculation, the bottom end of the water-resisting key layer is used as a starting point, the number, the position and the space size of a plurality of rock stratum anchoring holes which are arranged along the anchoring vertical shaft in a layered mode are determined according to the number, the buried depth, the thickness and the lithology of each rock stratum between the main key layer and the water-resisting key layer, after grouting anchoring agent is selected, generating bearing mathematical models of each anchoring vertical well unit combination body comprising a rock stratum anchoring hole, an anchoring grouting pipe and an anchoring slurry filling body according to the designed anchoring strength of the grouting anchoring agent, and fitting the bearing mathematical models of each anchoring vertical well unit combination body with the geological mathematical model to generate an integral rock stratum anchoring bearing mathematical model;
b. and (3) well construction: according to the integral rock stratum anchoring bearing mathematical model, each anchoring vertical well is arranged from the ground to a water-proof key layer, the hole making operation is carried out at the set position of a rock stratum anchoring hole, the corresponding anchoring grouting pipes are respectively arranged in each anchoring vertical well, and the well cementation operation is carried out after the bottom ends of the anchoring grouting pipes are ensured to be positioned at the bottom of the anchoring vertical wells;
c. rock stratum anchoring construction and ore bed mining: injecting anchoring slurry into an anchoring slurry injection pipe in an anchoring vertical shaft in a pressure slurry injection mode before or in the process of mining the to-be-mined ore bed, and injecting the anchoring slurry into the anchoring slurry injection pipe in the anchoring vertical shaft in a pressure slurry injection mode every time when the pressure slurry injection is performed in the process of mining the to-be-mined ore bed through an ore bed area range corresponding to the bottom end of the anchoring vertical shaft in the process of advancing a working face; after the anchoring slurry is completely filled in the whole anchoring vertical shaft space, pressure grouting is continuously carried out; and after the anchoring slurry is completely solidified, removing the pressure grouting equipment.
As a further improvement of the present invention, in the working face advancing process in the step c, a manner is adopted in which the working face advances forward while filling the gob formed rearward, or a manner is adopted in which the working face advances forward while supporting the ceiling of the gob formed rearward.
As a further improvement of the invention, at least the anchoring grouting pipe section between the main critical layer and the water-stop critical layer is a perforated pipe structure comprising a plurality of radial through holes penetrating the pipe wall in the radial direction.
As a preferable aspect of the present invention, the structure of the rock formation anchoring cavern is a shell-shaped structure including an upper dome structure and a lower dome structure.
As a further improvement of the invention, rock formation anchoring cavities are correspondingly arranged in each rock formation.
As a further improvement of the invention, a plurality of rock stratum anchoring cavities are arranged in the same large-thickness rock stratum according to the lithology and the thickness of each rock stratum.
As a further improvement of the invention, rock stratum anchoring cavities in rock strata with the same large thickness are in a mode of large quantity and small space size along the axial direction of the anchoring vertical shaft or in a mode of small quantity and large space size along the axial direction of the anchoring vertical shaft according to the lithology and the thickness of each rock stratum.
As a further improvement of the invention, the outer surface and/or the inner surface of the anchoring grouting pipe is/are provided with a convex structure which can increase the strength of the anchoring connection.
As a further improvement scheme of the invention, the convex structures are convex ring structures which are uniformly distributed along the axial direction of the anchoring grouting pipe or spiral convex structures which are arranged along the axial direction of the anchoring grouting pipe.
The specific calculation method in step a is as follows:
when the face is advanced L distance forward, due to the angle of fracture (θ) of the formation in the strike direction1，θ2) In contrast, the hanging length (a) of the strike direction key layer when the separation space first appears under the j-th layer (key layer)j) The relationship with L is
Figure BDA0003587551400000031
Suspension width (b) of critical layer in oblique directionjIn meters) and face width (B in meters) are:
Figure BDA0003587551400000032
Figure BDA0003587551400000033
S1＝LB
S2＝an+1bn+1
in the formula, an+1The length of the suspended roof of the rock mass along the trend direction is meter; b is a mixture ofn+1For the length of suspended roof of rock mass in the direction of inclinationDegree, in meters; h is the vertical distance between overlying strata and a coal bed, and the unit is meter; h isn+1The maximum height of the overburden separation layer is measured in meters; l represents the advancing distance of the working face, and the unit is meter; theta1A rock stratum breaking angle at the side of the open-cut hole; theta2Is the rock stratum breaking angle of the working face side; s1Representing the area of the working face which is recovered; s2Representing the suspended area of the overburden separation layer;
assuming that the spacing between the anchor grouting pipes is LjRow pitch LpThe anchoring area of each anchoring grouting pipe is A ═ Lj·LpN is required to be drilled in the direction of the working surface1＝L/LpThe number of the anchoring grouting pipes needs to be n in the inclined direction of the working face2＝L/LpThe N is equal to N, and the number of the anchoring grouting pipes is equal to N1·n2A number of anchoring grout pipes;
the weight to be carried by each anchor slip casting pipe is
Figure BDA0003587551400000041
In the formula (I), the compound is shown in the specification,
Figure BDA0003587551400000042
is the average density of the overburden;
assuming that the rock mass and the binding material are elastic materials with the same property, the rock mass is regarded as a half space by utilizing the displacement solution of the Mindlin problem, the anchoring grouting pipe is half infinite long, the displacement of the rock mass at the orifice is equal to the total elongation of the anchor rod body, and the ultimate drawing force Pu of the full-length binding type anchoring grouting pipe is derived to be
Figure BDA0003587551400000043
Figure BDA0003587551400000044
Wherein E is the modulus of elasticity of the rock mass; mu is the poisson ratio of the rock mass; ebThe elastic modulus of the anchoring grouting pipe; tau isuThe ultimate bonding stress of the anchoring slurry and the anchoring grouting pipe, wherein alpha is the radius of the anchoring grouting pipe;
the anchoring slip pipe needs to bear the weight of
Figure BDA0003587551400000045
Wherein k is an anchoring environment influence coefficient.
Compared with the prior art, the fracture zone global grouting subsidence reducing method capable of preventing the roof from permeating water adopts the steps of firstly drilling a plurality of anchoring vertical wells arranged in an array from the ground to a water-resisting key layer and making holes in each overlying rock layer above the water-resisting key layer to form rock layer anchoring holes before mining the ore layer, then respectively placing corresponding anchoring grouting pipes into each anchoring vertical well and then performing well cementation operation, finally injecting anchoring grout into the anchoring grouting pipes in the anchoring vertical wells in a continuous pressure grouting mode before mining or during mining the ore layer to be mined to perform anchoring, forming a full-length anchoring mode along the depth direction of the water-resisting key layer after the anchoring grout is completely cured so as to solve the problem that the damage influence is generated on the water-resisting key layer due to mining movement of later mining of the ore layer, and arranging each vertical well unit combination body of the array structure in the burial range of the layer to be mined, the diameter of the anchoring vertical shaft, the size of the anchoring grouting pipe and the space size of a rock stratum anchoring hole can be different according to different bearing positions, and because the anchoring vertical shaft is subjected to continuous pressure grouting before a mineral layer to be mined is mined or the anchoring vertical shaft is subjected to continuous pressure grouting anchoring after a working face pushes each mineral layer area range corresponding to the bottom end of the anchoring vertical shaft in the mining process, sufficient anchoring hardening time can be provided, the anchoring strength and effect of each overlying rock stratum above a water-proof key layer can be ensured, not only are each anchoring vertical shaft unit assembly anchored along the full length of the anchoring vertical shaft, but also each anchoring vertical shaft unit assembly comprises a plurality of rock stratum anchoring convex ring structures formed by filling rock stratum anchoring holes with anchoring grout, and each rock stratum anchoring convex ring structure not only can provide the bearing supporting force and the supporting force of the rock stratum, And load can be evenly applied to the whole anchoring vertical well unit anchoring supporting body comprising the anchoring grouting pipe and the anchoring slurry filling body, and all anchoring vertical well unit assemblies which are arranged according to the set row spacing array in the corresponding buried range of the layer to be mined form a group anchoring effect on an overlying rock layer above the water-resisting key layer together, so that the damage influence of mining on the water-resisting key layer can be greatly reduced, and the probability of roof water-permeating accidents is further reduced to the maximum extent.
Drawings
FIG. 1 is a schematic structural diagram of the present invention for drilling and setting anchoring vertical well and making cave;
FIG. 2 is a schematic view of the present invention after placement of the anchoring grout pipe into the anchoring shaft;
FIG. 3 is a schematic view of the present invention with the working face pushed forward and the goaf formed behind filled;
FIG. 4 is a schematic view of overburden loading during mining of a mineral seam.
In the figure: 1. the method comprises the following steps of (1) anchoring a vertical shaft, (2) anchoring a grouting pipe, (3) a rock stratum anchoring hole, (4) a main key layer, (5) a water-resisting key layer, (6) and a layer to be mined.
Detailed Description
The invention is further described below with reference to the accompanying drawings.
The fracture zone global grouting subsidence reducing method capable of preventing the top plate from permeating water comprises the following steps:
a. preparing for well construction: detecting and determining the buried depth, the thickness and the buried range of the layer to be mined 6, detecting and determining the number, the buried depth, the thickness and the lithology of overlying strata of the layer to be mined 6, determining the layer positions and the depths of the main key layer 4 and the water-resisting key layer 5, and constructing a geological mathematical model; based on a geological mathematical model, the well diameter of an anchoring vertical shaft 1 corresponding to the burying range of a layer 6 to be mined, the number of the anchoring vertical shafts 1, the array row spacing and the size of an anchoring grouting pipe 2 matched with the anchoring vertical shaft 1 are determined according to the depth of a waterproof key layer 5, the number and the lithology of each overlying rock stratum above the waterproof key layer 5, the number, the position and the space size of a plurality of rock stratum anchoring cavities 3 which are arranged in layers along the anchoring vertical shaft 1 are determined according to the number, the burying depth, the thickness and the lithology of each rock stratum between a main key layer 4 and the waterproof key layer 5 by taking the bottom end of the waterproof key layer 5 as a starting point, the rock stratum anchoring cavities 3 are correspondingly arranged in each rock stratum or among each rock stratum, the structure of the rock stratum anchoring cavities 3 is preferably a shell-shaped structure comprising an upper arch crown structure and a lower arch crown structure, and the well-flowing property of a composite grouting material, a composite rebar cement and the like are selected, After the grouting anchoring agent with good permeability, good cohesiveness and high strength is used, generating bearing mathematical models of each anchoring vertical well unit combination comprising a rock stratum anchoring hole 3, an anchoring grouting pipe 2 and an anchoring slurry filling body according to the designed anchoring strength of the grouting anchoring agent, and fitting the bearing mathematical models of each anchoring vertical well unit combination with a geological mathematical model to generate an integral rock stratum anchoring bearing mathematical model; on the premise of meeting the anchoring support strength, according to the lithology and the thickness of each rock stratum, the rock stratum anchoring cavities 3 in the same large-thickness rock stratum can be set to be multiple, the rock stratum anchoring cavities 3 in the same large-thickness rock stratum can be set to be in a large quantity and small space size mode along the axial direction of the anchoring vertical well 1, and also can be in a small quantity and large space size mode along the axial direction of the anchoring vertical well 1, for fully utilizing the supporting function of the main key layer 4 and the water-resisting key layer 5, the space size of the rock stratum anchoring cavities 3 corresponding to the main key layer 4 and the water-resisting key layer 5 can be designed to be larger than the space size of the rock stratum anchoring cavities 3 corresponding to other rock stratums.
b. And (3) well construction: as shown in fig. 1, each anchoring vertical shaft 1 is arranged from the ground to the water-resisting key layer 5 according to the whole rock stratum anchoring bearing mathematical model, and the hole making operation is carried out at the set position of the rock stratum anchoring hole 3 respectively, the hole making mode can adopt a hydraulic cutting hole making mode, as shown in fig. 2, the corresponding anchoring grouting pipes 2 are respectively arranged in each anchoring vertical shaft 1, and the well cementation operation is carried out after the bottom ends of the anchoring grouting pipes 2 are positioned at the bottom of the anchoring vertical shafts 1.
c. Rock stratum anchoring construction and ore bed mining: injecting prepared anchoring slurry into the anchoring slurry pipe 2 in the anchoring vertical shaft 1 in a continuous pressure slurry injection mode before or in the process of mining the mineral bed 6 to be mined, as shown in figure 3, and injecting prepared anchoring slurry into the anchoring slurry pipe 2 in the anchoring vertical shaft 1 in a pressure slurry injection mode every time the mine bed area range corresponding to the bottom end of one anchoring vertical shaft 1 passes in the process of advancing a working face when pressure slurry injection is performed in the process of mining the mineral bed 6 to be mined; when the anchoring slurry fills the space between the wall of the anchoring vertical shaft 1 and the outer wall of the anchoring grouting pipe 2 from bottom to top, each rock stratum anchoring hole 3 is sequentially filled, after the whole space of the anchoring vertical shaft 1 is completely filled, pressure grouting is continuously carried out, the anchoring slurry fills cracks around the anchoring vertical shaft 1 and the rock stratum anchoring holes 3, the anchoring slurry is completely cured, the anchoring of the anchoring grouting pipe 2 of each anchoring vertical shaft unit along the whole length of the anchoring vertical shaft 1 is completed, and pressure grouting equipment is removed.
The method for reducing subsidence of fracture zone global grouting capable of preventing roof from being permeable adopts the steps of firstly drilling a plurality of anchoring vertical shafts 1 arranged in an array from the ground to a water-resisting key layer 5 before mining an ore layer according to the burial range of a layer 6 to be mined, forming rock stratum anchoring holes 3 in each overlying rock stratum above the water-resisting key layer 5, then respectively placing corresponding anchoring grouting pipes 2 into each anchoring vertical shaft 1 for well cementation operation, finally injecting anchoring grout into the anchoring grouting pipes 2 in the anchoring vertical shafts 1 in a continuous pressure grouting mode before mining or in the mining process of the layer 6 to be mined for anchoring, forming a full-length anchoring mode along the burial depth direction of the water-resisting key layer 5 after the anchoring grout is completely cured so as to solve the problem that the later mining of the layer 5 generates damage influence, and corresponding to each anchoring well unit assembly arranged in an array structure in the burial range of the layer 6 to be mined, the diameter of the anchoring vertical shaft 1, the size of the anchoring grouting pipe 2 and the space size of the rock stratum anchoring cavity 3 can be different according to different bearing positions, because the anchoring vertical shaft 1 is subjected to continuous pressure grouting before the mining of a mineral layer 6 to be mined or the anchoring vertical shaft 1 is subjected to continuous pressure grouting anchoring after a working face pushes each mineral layer region range corresponding to the bottom end of one anchoring vertical shaft 1 in the mining process, sufficient anchoring hardening time can be provided, the anchoring strength and effect of each overlying rock stratum above a water-proof key layer 5 can be ensured, each anchoring vertical shaft unit assembly is anchored along the whole length of the anchoring vertical shaft 1, each anchoring vertical shaft unit assembly comprises a plurality of rock stratum anchoring convex ring structures formed by filling the rock stratum anchoring cavities 3 with anchoring grout, and each rock stratum convex ring structure can not only provide the bearing supporting force, the supporting force and the anchoring effect of the rock stratum, And load can be evenly applied to the whole anchoring vertical well unit anchoring supporting body comprising the anchoring grouting pipe 2 and the anchoring slurry filling body, and all anchoring vertical well unit assemblies which are arranged according to the set row spacing array in the embedding range of the corresponding layer 6 to be mined form a group anchoring effect on an overlying rock layer above the water-resisting key layer 5, so that the damage influence of mining on the water-resisting key layer 5 can be greatly reduced, and the probability of roof water penetration accidents is further reduced to the maximum extent.
The specific calculation method in step a is as follows:
as shown in FIG. 4, as the face advances L distances forward, due to the fracture angle (θ) of the formation in the strike direction1，θ2) In contrast, the hanging length (a) of the strike direction key layer when the separation space first appears under the j-th layer (key layer)j) The relationship with L is
Figure BDA0003587551400000071
Suspension width (b) of critical layer in oblique directionjIn meters) and face width (L in meters) are:
Figure BDA0003587551400000072
Figure BDA0003587551400000073
S1＝LB
S2＝an+1bn+1
in the formula, an+1The length of the suspended roof of the rock mass along the trend direction is meter; bn+1The length of the suspended roof of the rock mass along the inclined direction is meter; h is the vertical distance between overlying strata and a coal bed, and the unit is meter; h isn+1The maximum height of the overburden separation layer is measured in meters; l represents the advancing distance of the working face, and the unit is meter; theta1A rock stratum breaking angle at the side of the open-cut hole; theta2A rock formation fracture angle at the working face side; s1Representing the area of the working face which is recovered; s. the2Representing the suspended area of the overburden separation layer;
assuming that the spacing between the anchor grouting pipes is LjRow pitch LpThe anchoring area of each anchoring grouting pipe is A ═ Lj·LpN is required to be drilled in the direction of the working surface1＝L/LpThe number of anchoring grouting pipes needs to be n in the inclined direction of the working face2＝L/LpThe N is equal to N, and the number of the anchoring grouting pipes is equal to N1·n2A number of anchor grout tubes.
The weight that each anchor slip casting pipe needs to bear is as follows:
Figure BDA0003587551400000081
in the formula (I), the compound is shown in the specification,
Figure BDA0003587551400000082
as an average density of overburden, 2500kg/m is generally taken as an empirical value3。
Considering the situation that the full-length bonded anchoring grouting pipe is buried in a rock body and the end head of the full-length bonded anchoring grouting pipe is subjected to tensile pulling force, assuming that the rock body and the bonding material are elastic materials with the same property, by utilizing the displacement solution of the Mindlin problem, the rock body is regarded as a half space, the anchoring grouting pipe is half-infinite long, the displacement of the rock body at an orifice is equal to the total elongation of an anchor rod body, and the ultimate pulling force Pu of the full-length bonded anchoring grouting pipe is derived to be
Figure BDA0003587551400000083
Figure BDA0003587551400000084
Wherein E is the modulus of elasticity of the rock mass; mu is the poisson ratio of the rock mass; ebThe elastic modulus of the anchoring grouting pipe; tau.uThe ultimate bonding stress of the anchoring slurry and the anchoring grouting pipe, wherein alpha is the radius of the anchoring grouting pipe;
the anchoring slip pipe needs to bear the weight of
Figure BDA0003587551400000085
In the formula, k is an anchoring environment influence coefficient and is mainly related to rock formation lithology, burial depth, anchoring length and the like.
In order to facilitate the anchoring slurry to quickly fill the space between the wall of the anchoring vertical shaft 1 and the outer wall of the anchoring grouting pipe 2 and each rock stratum anchoring cavity 3, as a further improvement scheme of the invention, at least the pipe section of the anchoring grouting pipe 2 positioned between the main key layer 4 and the waterproof key layer 5 is of a perforated pipe structure comprising a plurality of radial through holes penetrating through the pipe wall in the radial direction.
In order to achieve a better overall-length anchoring effect of the anchoring grouting pipe 2, as a further improvement scheme of the invention, the outer surface and/or the inner surface of the anchoring grouting pipe 2 is/are provided with a convex structure capable of increasing the anchoring connection strength, and the convex structure can be a convex ring structure uniformly distributed along the axial direction of the anchoring grouting pipe 2 or other structural forms such as a spiral convex structure distributed along the axial direction of the anchoring grouting pipe 2.
In order to further reduce the destructive influence of the mining and mining of the ore bed on the water-resisting key layer 5, as a further improvement of the invention, as shown in fig. 3, in the working face advancing process in the step c, the working face is advanced and the goaf formed at the rear is filled with waste such as gangue, or a mode of supporting the top plate of the goaf formed at the rear while the working face is pushed forwards is adopted, the mode of supporting the top plate of the goaf can adopt a mode of reproducing a steel ladle supporting column, and aiming at a specific to-be-mined layer 6 which is easy to cause a bottom-bulging phenomenon and is made of soft rock or water-swelling rock and the like, the bottom plate of the goaf can be artificially perforated or grooved, so that the bottom plate of the goaf is artificially controlled to be bulged and then contacted with the top plate of the goaf and bear load, and the top plate of the goaf is supported by utilizing a bottom-bulging top-connecting mode.

Claims (10)

1. The utility model provides a can prevent permeable fracture zone universe slip casting of roof and reduce heavy method which characterized in that specifically includes following steps:
a. preparing for well construction: detecting and determining the buried depth, the thickness and the buried range of the layer (6) to be mined, detecting and determining the number, the buried depth, the thickness and the lithology of overlying strata of the layer (6) to be mined, determining the position and the depth of a main key layer (4) and a water-resisting key layer (5), and constructing a geological mathematical model; based on a geological mathematical model, the hole diameter of an anchoring vertical shaft (1), the number of the anchoring vertical shafts (1), the array row spacing and the size of an anchoring grouting pipe (2) matched with the anchoring vertical shaft (1) corresponding to the burying range of a layer (6) to be mined are determined according to the depth of a waterproof key layer (5), the number of overlying strata above the waterproof key layer (5) and lithology calculation, the number, the position and the space size of a plurality of stratum anchoring cavities (3) which are arranged in layers along the anchoring vertical shaft (1) are determined at least according to the number, the burying depth, the thickness and the lithology calculation of each stratum between a main key layer (4) and the waterproof key layer (5) by taking the bottom end of the waterproof key layer (5) as a starting point, and after grouting anchoring agents are selected, bearing mathematical anchoring models including the stratum anchoring cavities (3), the anchoring grouting pipes (2) and anchoring grout filling bodies are generated according to the design anchoring strength of the grouting anchoring agents, fitting each anchoring vertical shaft unit combination body bearing mathematical model with a geological mathematical model to generate an integral rock stratum anchoring bearing mathematical model;
b. and (3) well construction: according to the integral rock stratum anchoring bearing mathematical model, each anchoring vertical well (1) is arranged from the ground to a water-proof key layer (5), cave-making operation is carried out at the set position of a rock stratum anchoring cave (3) respectively, corresponding anchoring grouting pipes (2) are arranged in each anchoring vertical well (1) respectively, and well cementation operation is carried out after the bottom ends of the anchoring grouting pipes (2) are ensured to be positioned at the bottom of each anchoring vertical well (1);
c. rock stratum anchoring construction and ore bed mining: injecting anchoring slurry into an anchoring grouting pipe (2) in an anchoring vertical shaft (1) in a pressure grouting mode before or in the process of mining an ore bed (6) to be mined, and injecting the anchoring slurry into the anchoring grouting pipe (2) in the anchoring vertical shaft (1) in a pressure grouting mode every time an ore bed region range corresponding to the bottom end of the anchoring vertical shaft (1) passes in the process of advancing a working face when the pressure grouting is performed in the process of mining the ore bed (6) to be mined; after the anchoring slurry is completely filled in the space of the whole anchoring vertical shaft (1), pressure grouting is continuously carried out; and after the anchoring slurry is completely solidified, removing the pressure grouting equipment.
2. The method according to claim 1, wherein during the advancing of the working surface in step c, the working surface is advanced and the goaf formed behind is filled, or the working surface is advanced and the roof of the goaf formed behind is supported.
3. The method for preventing the top plate from permeating water and reducing the subsidence of the fractured zone through global grouting according to claim 1 or 2, characterized in that at least the section of the anchoring grouting pipe (2) between the main critical layer (4) and the water-resisting critical layer (5) is a floral pipe structure comprising a plurality of radial through holes penetrating through the pipe wall in the radial direction.
4. The method for reducing subsidence of fractured zone full grouting capable of preventing the roof from permeating water according to claim 1 or 2, wherein the structure of the rock stratum anchoring cavity (3) is a shell-shaped structure comprising an upper arch structure and a lower arch structure.
5. The method for reducing the subsidence of the fractured zone of the permeable roof by global grouting according to claim 1 or 2, wherein rock stratum anchoring cavities (3) are correspondingly arranged in each rock stratum.
6. The method for reducing subsidence of fractured zone of permeable roof by global grouting according to claim 5, wherein a plurality of rock stratum anchoring cavities (3) are arranged in the same large thickness rock stratum according to the lithology and thickness of each rock stratum.
7. The method for reducing the subsidence of the fractured zone of the permeable roof by global grouting according to claim 6, wherein rock stratum anchoring cavities (3) in rock strata with large thickness adopt a large number and a small space size along the axial direction of the anchoring vertical shaft (1) or adopt a small number and a large space size along the axial direction of the anchoring vertical shaft (1) according to the lithology and thickness of each rock stratum.
8. The method for reducing the subsidence of the fractured zone of the permeable roof by global grouting according to claim 1 or 2, wherein the outer surface and/or the inner surface of the anchoring grouting pipe (2) is/are provided with a convex structure capable of increasing the anchoring connection strength.
9. The method for preventing the permeable crack zone global grouting subsidence of the top plate according to claim 4, characterized in that the convex structures are convex ring structures uniformly distributed along the axial direction of the anchoring grouting pipe (2) or spiral convex structures arranged along the axial direction of the anchoring grouting pipe (2).
10. The method for reducing the subsidence of the fractured zone of the permeable roof by global grouting according to claim 1 or 2,
the specific calculation method in step a is as follows:
when the face is advanced L distance forward, due to the angle of fracture (θ) of the formation in the strike direction1，θ2) In contrast, when the first time comes under the j-th layer (key layer)When the space is separated, the hanging length (a) of the key layer in the direction of the trendj) The relationship with L is
Figure FDA0003587551390000021
Suspension width (b) of critical layer in oblique directionjIn meters) and face width (B in meters) are:
Figure FDA0003587551390000031
Figure FDA0003587551390000032
S1＝LB
S2＝an+1bn+1
in the formula, an+1The length of the suspended roof of the rock mass along the trend direction is meter; bn+1The length of the suspended roof of the rock mass along the inclined direction is meter; h is the vertical distance between overlying strata and a coal bed, and the unit is meter; h isn+1The maximum height of the overburden separation layer is measured in meters; l represents the advancing distance of the working face, and the unit is meter; theta1A rock stratum breaking angle at the side of the open-cut hole; theta2Is the rock stratum breaking angle of the working face side; s1Representing the area of the working face which is recovered; s2Representing the suspended area of the overburden separation layer;
assuming that the spacing between the anchor grouting pipes is LjRow pitch LpThe anchoring area of each anchoring grouting pipe is A ═ Lj·LpN is required to be drilled in the direction of the working surface1＝L/LpThe number of the anchoring grouting pipes needs to be n in the inclined direction of the working face2＝L/LpThe N is equal to N, and the number of the anchoring grouting pipes is equal to N1·n2Number of anchoring grouting pipes；
The weight to be carried by each anchor slip casting pipe is
Figure FDA0003587551390000033
In the formula (I), the compound is shown in the specification,
Figure FDA0003587551390000034
is the average density of the overburden;
assuming that the rock mass and the binding material are elastic materials with the same property, the rock mass is regarded as a half space by utilizing the displacement solution of the Mindlin problem, the anchoring grouting pipe is semi-infinitely long, the displacement of the rock mass at the orifice is equal to the total elongation of the anchor rod body, and the ultimate drawing force Pu of the full-length binding type anchoring grouting pipe is derived to be
Figure FDA0003587551390000035
Figure FDA0003587551390000036
Wherein E is the modulus of elasticity of the rock mass; mu is the poisson ratio of the rock mass; ebThe elastic modulus of the anchoring grouting pipe; tau isuThe ultimate bonding stress of the anchoring slurry and the anchoring grouting pipe, wherein alpha is the radius of the anchoring grouting pipe;
the anchoring slip pipe needs to bear the weight of
Figure FDA0003587551390000037
Wherein k is an anchoring environment influence coefficient.
CN202210367007.1A 2022-04-08 2022-04-08 Fracture zone global grouting subsidence reducing method capable of preventing top plate from permeating water Pending CN114673532A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202210367007.1A CN114673532A (en) 2022-04-08 2022-04-08 Fracture zone global grouting subsidence reducing method capable of preventing top plate from permeating water

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202210367007.1A CN114673532A (en) 2022-04-08 2022-04-08 Fracture zone global grouting subsidence reducing method capable of preventing top plate from permeating water

Publications (1)

Publication Number Publication Date
CN114673532A true CN114673532A (en) 2022-06-28

Family

ID=82078459

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202210367007.1A Pending CN114673532A (en) 2022-04-08 2022-04-08 Fracture zone global grouting subsidence reducing method capable of preventing top plate from permeating water

Country Status (1)

Country Link
CN (1) CN114673532A (en)

Similar Documents

Publication Publication Date Title
CN108678769B (en) Anchor grouting and roof cutting main control entry retaining method for deep mining tunnel
CN103089275B (en) Control method of surrounding rocks in water-rich very-broken surrounding rock tunnel collapse sections
CN105971606B (en) A kind of thick sandstone coal wall recovery method
Zhang et al. Ground stability of underground gateroad with 1 km burial depth: a case study from Xingdong coal mine, China
CN110617067B (en) Low-risk construction method for full-section boundary advanced pipe shed of extremely-soft surrounding rock tunnel
CN101709651A (en) Grouting water blocking method for undersea tunnel
CN111535817A (en) Working face double-lane tunneling small coal pillar reinforcement construction method
Jiang et al. Failure mechanism analysis and support design for deep composite soft rock roadway: a case study of the Yangcheng coal mine in China
CN110284885A (en) Shield inspection-pit construction method
CN114483109B (en) Curtain grouting advanced large pipe shed through construction method for crossing tunnel fault fracture zone
CN112177635A (en) Construction method of step multiple advanced small guide pipe and construction method of overlapped tunnel
CN110778317A (en) Construction method for ground grouting filling drilling structure in caving zone in mining process
CN110656947A (en) Method for tunneling raised section of seabed bedrock
CN112145203A (en) Full-face advancing type sectional grouting construction method and overlapped tunnel construction method
Wu et al. Research on failure characteristics and zoning control technology of thick-soft surrounding rock for deep gob-side entry retaining
CN110552731A (en) top coal caving stoping roadway grouting anchor cable supporting structure and advanced supporting method thereof
CN113818882B (en) Method for recycling stope jack posts under loose tailing filling body
CN114673532A (en) Fracture zone global grouting subsidence reducing method capable of preventing top plate from permeating water
CN210622819U (en) Pipe shed and steel support combined supporting device
CN114892687A (en) A advance reinforced structure that advances that is used for opencut rock quality bedding slope to administer
Zhang et al. Research on the deformation and control technology of surrounding rock in entry retaining along the gob side
Qian et al. Deformation characteristics and control countermeasures for surrounding rock of deep roadway under mining disturbance: A case study
CN109441478B (en) Method for damping and reinforcing IV-type and V-type surrounding rock advanced rod system arch of tunnel
CN114673540A (en) Migration control method for underground rock stratum in mining area
CN113565566B (en) Construction method for dewatering, depressurizing and stabilizing tunnel face of water-rich composite stratum

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