Device and method for measuring expansion deformation of protected layer
Technical Field
The invention relates to the technical field of coal mines, in particular to a device and a method for measuring the expansion deformation of a protected layer.
Background
When the protective layer is mined for the first time in a mine to investigate the protection effect and the protection range, the expansion deformation of the protected layer needs to be measured. The expansion deformation of the protected layer is a key parameter for measuring the mining effect of the protected layer, the expansion deformation of the protected layer is accurately measured, the pressure relief and permeability increase rule of the protected layer during the mining of the protected layer is further mastered, and the method has important significance for controlling the gas of the protected layer.
The traditional method for measuring the expansion deformation of the protected layer is a deep base point method, namely a construction cross-layer drilling hole penetrates through a coal seam top plate to be not less than 1m, and a pair of steel wedges are respectively arranged on the coal seam top plate and a bottom plate to fix the deep base point, which is shown in figure 1. And welding a reinforcing steel bar with the diameter of 10mm on the steel wedge of the coal seam top plate, and penetrating the steel wedge of the coal seam bottom plate to the hole opening. A seamless steel pipe with the diameter of 15mm is welded on the steel wedge of the coal seam bottom plate and is sleeved on the steel bar connected with the steel wedge of the top plate. Under the mining action of the protective layer, the steel bars fixed on the top plate and the steel pipes fixed on the bottom plate move along with the top plate and the bottom plate, and the relative displacement of the steel bars and the steel pipes is the expansion deformation of the protective layer.
Chinese patent CN104482914A discloses a device for measuring expansion deformation of a remote protected layer, which comprises a coal seam roof base point fixer, a roof base point measuring line, a connecting pipe, a coal seam floor base point fixer, a floor base point measuring line, a protective sleeve and a sleeve connector. The top and bottom plates of the coal seam are provided with base point fixers which are connected in an inserting way through connecting pipes, and the wing wings on the periphery of the pipe body are in an open state, so that the expansion deformation of the protective layer is measured; chinese patent CN104344785A discloses an automatic testing device for coal seam slight deformation, which utilizes the deformation of the coal seam, and the stainless steel pipe and the steel wire rope generate relative displacement therewith, thereby driving the scale or the digital display meter to move, and measuring the deformation of the protective layer after the protective layer is mined.
The above techniques have some problems: the expansion deformation of the protected layer is measured by a deep base point method, and the fixed steel wedge and the steel wedge connected with the steel bar need to be conveyed to the position of the top plate of the drill hole to be fixed firmly. The steel wedges for connecting the reinforcing steel bars are manually conveyed to the target position of the drilled hole, the labor intensity is high, and the risk that objects slide down to injure people in the drilled hole exists when people work under the drilled hole. If the drilling depth exceeds 50m, it is difficult to fix the base point to the design position. The steel wedge is fixed on the coal seam top and bottom plate mainly by the friction force of the steel wedge and the wall of the drilling hole, when the pressure of the coal seam is relieved and the coal seam top and bottom plate is displaced, the stress condition of the steel wedge changes, and the steel wedge may be displaced in the drilling hole to influence the accuracy of a measuring result.
Disclosure of Invention
The invention aims to solve the technical problems that how to measure the expansion deformation of a protected layer by a deep base point method is high in labor intensity, the base point is difficult to fix to a designed position, the accuracy is poor and the like.
The invention solves the technical problems through the following technical means:
a protected layer expansion deformation measuring device comprises a guide pipe, a first hole sealing bag, a first bag grouting pipe, a sleeve, a second hole sealing bag, a second bag grouting pipe and a steel wire rope, wherein the guide pipe, the first hole sealing bag, the first bag grouting pipe, the sleeve, the second hole sealing bag, the second bag grouting pipe and the steel wire rope are arranged in a drill hole;
the drill holes are elevation cross-layer drill holes, and the drill holes penetrate through the protected coal seam from the holes formed in the coal rock wall and are constructed above the top plate of the protected coal seam;
the guide pipe comprises a round steel pipe body, a first check ring and a second check ring which are connected together; the first check ring is fixed at the lower end of the round steel pipe body; the second retaining ring is fixed at the upper end of the round steel pipe body;
two ends of the first hole sealing bag are fixedly connected with the middle part of the round steel pipe body, and the first hole sealing bag is positioned between the first retaining ring and the second retaining ring;
one end of the first bag grouting pipe is communicated with the interior of the first hole sealing bag, and the other end of the first bag grouting pipe extends out of the drill hole;
the sleeve is arranged in the drill hole, one end of the sleeve extends into the position above the bottom plate of the protected coal seam, and the other end of the sleeve is led out of the drill hole;
two ends of the second hole sealing bag are fixedly connected with the sleeve, and the second hole sealing bag is positioned below the protected coal seam floor;
one end of the second bag grouting pipe is communicated with the interior of the second hole sealing bag, and the other end of the second bag grouting pipe extends out of the drill hole;
one end of the steel wire rope is fixed on the round steel pipe body and corresponds to the position of the top plate of the protected coal seam, and the other end of the steel wire rope extends into the sleeve and is led out of the drill hole.
According to the invention, the guide pipe and the steel wire rope are accurately conveyed to the top plate of the protected coal seam by the drilling machine and the drill rod, and the sleeve is conveyed to the bottom plate of the protected coal seam under the guide of the steel wire rope, so that the problem that a deformation measuring device for deep drilling cannot be conveyed to a target position is solved, the labor intensity is low, and the safety is good; the steel wire rope and the sleeve are respectively fixed at preset positions of a top plate and a bottom plate of a protected coal seam by using a hole sealing bag grouting process, the stability is good, and the change of the top plate and the bottom plate of the protected coal seam can be accurately reflected.
Preferably, the guide tube further comprises a pointed cone fixedly connected to the top of the guide tube, and the diameter of the pointed cone is between the diameter of the drill rod and the diameter of the drill hole.
The second technical problem to be solved by the present invention is to provide a method for measuring the swelling deformation of a protected layer.
The invention solves the technical problems through the following technical means:
a method for measuring the expansion deformation amount of a protected layer comprises the following steps:
s1, drilling holes on the coal rock wall by adopting a drilling machine, a drill rod and a matched drill bit, drilling the bottom of each drilled hole to the position above the top plate of the protected coal bed, and withdrawing the drill rod and the matched drill bit;
s2, fixing a first hole sealing bag, a first bag grouting pipe and a steel wire rope on the round steel pipe body of the guide pipe, wherein the first hole sealing bag is fixed between a first retaining ring and a second retaining ring;
s3, inserting a guide pipe into an inner hole of a drill rod until the end of the drill rod is contacted with a first check ring, starting a drilling machine to simultaneously feed the guide pipe, a first hole sealing bag, a first bag grouting pipe and a steel wire rope into the hole bottom of a drilled hole, leading the other ends of the first bag grouting pipe and the steel wire rope out of the drilled hole, and stopping the drilling machine, wherein the position of the first check ring is positioned above the top plate of the protected coal seam;
s4, injecting cement slurry into the first hole sealing bag through the first bag grouting pipe, after the cement slurry is solidified, fixedly connecting one end of the steel wire rope with the top plate of the protected coal seam through the cement, starting a drilling machine, taking the drill rod off from the guide pipe, and measuring the displacement of the top plate of the protected coal seam;
s5, fixing a second hole sealing bag and a second bag grouting pipe on the sleeve, and then penetrating the sleeve on the steel wire rope and conveying the sleeve to the position of the bottom plate of the protected coal seam;
s6, injecting cement slurry into the second hole sealing bag through a second bag grouting pipe, and fixing the casing at the position of the bottom plate of the protected coal seam after the cement slurry is solidified;
and S7, recording the positions of the sleeve and the steel wire rope from the coal rock wall, measuring the displacement of the protected coal seam floor, and further calculating the expansion deformation of the protected layer after the protective layer is mined.
Further, the inclination angle between the drill hole and the rock wall surface is 30-90 degrees.
Further, the bottom of the bore hole extends to 2m above the top plate of the protected coal seam.
Further, the diameter of the drill hole is 94-133 mm.
Further, the guide tube is round steel with the diameter of 16-18 mm.
Further, the diameter of the steel wire rope is 3-5 mm.
Further, the first retainer ring is sleeved at a position which is 0.5m close to the lower end of the guide pipe;
the second baffle is sleeved at a position which is 0.5m close to the upper end of the guide pipe;
and the outer diameters of the first retainer ring and the second retainer ring are 30-50 mm.
Further, the pressure of the injected cement slurry in the step S4 and the step S6 is not less than 2 MPa.
The invention has the advantages that:
(1) according to the invention, the guide pipe and the steel wire rope are accurately conveyed to the top plate of the protected coal seam by the drilling machine and the drill rod, and the sleeve is conveyed to the bottom plate of the protected coal seam under the guide of the steel wire rope, so that the problem that a deformation measuring device for deep drilling cannot be conveyed to a target position is solved, the labor intensity is low, and the safety is good; the steel wire rope and the sleeve are respectively fixed at preset positions of a top plate and a bottom plate of a protected coal seam by using a hole sealing bag grouting process, the stability is good, and the change of the top plate and the bottom plate of the protected coal seam can be accurately reflected.
(2) The invention provides a device and a method for measuring the expansion deformation of a protected layer, which are suitable for measuring the expansion deformation of the protected layer by drilling holes with the depth within 100m and the elevation angle of 30-90 degrees, and have wide application range.
Drawings
FIG. 1 is a schematic structural view of a conventional deep foundation point method for measuring the amount of expansion deformation of a layer to be protected according to the present invention;
fig. 2 is a schematic structural view of a device for measuring an amount of swelling deformation of a protected layer according to the present invention.
The reference numbers illustrate:
1. drilling; 2. a guide tube; 21. a round steel pipe body; 22. a first retainer ring; 23. a second retainer ring; 24. a pointed cone; 3. a first hole sealing bag; 4. a first bladder grouting pipe; 5. a sleeve; 6. a second hole sealing bag; 7. a second bladder grouting pipe; 8. a wire rope; 101. a coal rock wall; 102. the coal seam to be protected.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example one
As shown in fig. 2, the present embodiment discloses a device for measuring the amount of expansion deformation of a protected layer, which includes a guide tube 2, a first sealing bag 3, a first bag grouting tube 4, a sleeve 5, a second sealing bag 6, a second bag grouting tube 7 and a steel wire rope 8, which are arranged in a borehole 1.
As shown in fig. 2, and with particular reference to the orientation of fig. 2, reference numerals 101 and 102 are the rock wall and the protected coal seam, respectively; the drill hole 1 is formed by drilling a hole into the rock wall 101 by using an existing drilling machine, and the bottom of the drill hole 1 extends to the position above the top plate of the protected coal seam 102.
As shown in fig. 2, and specifically using the position of fig. 2 as a reference, the guide tube 2 is disposed at the bottom of the borehole 1, the guide tube 2 includes a round steel tube body 21, a first retainer ring 22 and a second retainer ring 23 that are connected together, the round steel tube body 21 is an existing steel tube structure, the first retainer ring 22 is welded at the lower end of the round steel tube body 21, the first retainer ring 22 is located above the top plate of the protected coal seam 102, and the second retainer ring 23 is welded at the upper end of the round steel tube body 21.
As shown in fig. 2, two ends of the first hole sealing pocket 3 are fixedly connected with the middle part of the round steel pipe body 21 and are positioned between the first retaining ring 22 and the second retaining ring 23, the first hole sealing pocket 3 is pressed against the inner wall of the drill hole 1 after cement slurry is injected into the first hole sealing pocket 3, and the first hole sealing pocket 3 is matched with the inner diameter of the drill hole 1;
the first bag grouting pipe 4 and the first hole sealing bag 3 are integrally formed, one end of the first bag grouting pipe 4 is communicated with the inside of the first hole sealing bag 3, and the other end of the first bag grouting pipe 4 extends out of the drill hole 1.
As shown in fig. 2, and with particular reference to the orientation of fig. 2, the casing 5 of this embodiment is positioned such that one end extends above the floor of the protected coal seam 102 and the other end of the casing 5 exits the exterior of the borehole 1.
As shown in fig. 2, the second hole sealing bag 6 is located at the protected coal seam floor 102, and two ends of the second hole sealing bag 6 are fixedly connected with the casing 5; the second hole sealing bag 6 is abutted against the inner wall of the drill hole 1 after cement slurry is injected into the second hole sealing bag 6, and the second hole sealing bag 6 is matched with the inner diameter of the drill hole 1;
the second bag grouting pipe 7 and the second hole sealing bag 6 are integrally formed, one end of the second bag grouting pipe 7 is communicated with the inside of the second hole sealing bag 6, and the other end of the second bag grouting pipe 7 extends out of the drill hole 1.
As shown in fig. 2, the upper end of the wire rope 8 of the present embodiment is fixed on the outer annular wall of the round steel pipe body 21, the upper end of the wire rope 8 corresponds to the position of the roof of the protected coal seam 102, and the lower end of the wire rope 8 passes through the inside of the casing 5 and can extend out of the borehole 1.
The working principle is as follows: before the protective layer is mined, a drilling machine and a drill rod for constructing a drill hole 1 are utilized to fixedly connect a guide pipe 2 with a first hole sealing bag 3, a first bag grouting pipe 4, a steel wire rope 8 and the like to be sent above the top plate of a protected coal seam 102 of the drill hole 1, grouting is fixed, and the displacement of the top plate of the protected coal seam 102 is measured; fixing the hole sealing component by using a sleeve 5, then threading a steel wire rope 8, conveying the hole sealing component to a position below the bottom plate of the protected coal seam 102 of the drill hole 1, grouting and fixing, and measuring the displacement of the bottom plate of the protected coal seam 102; after the protective layer is mined, the expansion deformation of the protected coal seam 102 after the protective layer is mined is calculated by using the displacement of the top plate and the displacement of the bottom plate of the protected coal seam.
Compared with the prior art, the invention has the following advantages: firstly, the guide pipe 2 and the steel wire rope 8 are accurately conveyed to the top plate of the protected coal seam 102 by the drilling machine and the drill rod, and the sleeve 5 is conveyed to the bottom plate of the protected coal seam 102 under the guide of the steel wire rope 8, so that the problem that a deformation measuring device of the deep drilling hole 1 cannot be conveyed to a target position is solved, and the device is low in labor intensity and good in safety; the steel wire rope 8 and the sleeve 5 are respectively fixed at preset positions of the top plate and the bottom plate of the protected coal seam 102 by using a hole sealing bag grouting process, the stability is good, and the changes of the top plate and the bottom plate of the protected coal seam 102 can be accurately reflected. Secondly, the invention provides a device and a method for measuring the expansion deformation of a protected layer, which are suitable for measuring the expansion deformation of the protected layer by a drill hole 1 with the depth within 100m and the elevation angle of 30-90 degrees, and have wide application range.
Example two
The present embodiment differs from the above embodiments in that: a method for measuring the expansion deformation amount of a protected layer comprises the following steps:
s1, constructing a drill hole 1 on the rock wall 101 by adopting a drilling machine, a drill rod and a matched drill bit, drilling the bottom of the drill hole 1 to be above the top plate of the protected coal seam 102, and withdrawing the drill rod and the matched drill bit;
s2, fixing a first hole sealing bag 3, a first bag grouting pipe 4 and a steel wire rope 8 on the round steel pipe body 21 of the guide pipe 2, wherein the first hole sealing bag 3 is fixed between a first retaining ring 22 and a second retaining ring 23;
s3, inserting the guide pipe 2 into the inner hole of the drill rod until the end of the drill rod is contacted with the first check ring 22, then starting the drilling machine to simultaneously feed the guide pipe 2, the first hole sealing bag 3, the first bag grouting pipe 4 and the steel wire rope 8 into the hole bottom of the drill hole 1, wherein the position of the first check ring 22 is located above the top plate of the protected coal seam 102, and simultaneously leading out the other ends of the first bag grouting pipe 4 and the steel wire rope 8 to the outside of the drill hole 1, and stopping the drilling machine;
s4, injecting cement slurry into the first hole sealing bag 3 through the first bag grouting pipe 4, after the cement slurry is solidified, fixedly connecting one end of the steel wire rope 8 with the top plate of the protected coal seam 102 through the cement, starting a drilling machine, taking off the drill rod from the guide pipe 2, and measuring the displacement of the top plate of the protected coal seam 102;
s5, fixing the second hole sealing bag 6 and the second bag grouting pipe 7 on the sleeve 5, and then penetrating the sleeve 5 on the steel wire rope 8 and sending the sleeve to the bottom plate of the protected coal seam 102;
s6, cement slurry is injected into the second hole sealing bag 6 through the second bag grouting pipe 7, and the casing 5 can be fixed at the position of the bottom plate of the protected coal seam 102 after the cement slurry is solidified;
and S7, recording the positions of the sleeve 5 and the steel wire rope 8 from the coal rock wall 101, measuring the displacement of the bottom plate of the protected coal seam 102, and further calculating the expansion deformation of the protected layer after the protective layer is mined.
The inclination angle of the drill hole 1 of the embodiment is 30-90 degrees; the bottom of the borehole 1 extends to a position 2m above the top plate of the protected coal seam 102; the diameter of the bore hole 1 is 94-133 mm.
The round steel pipe body 21 of this embodiment is a round steel with a diameter of 16-18 mm.
The diameter of the steel wire rope 8 is 3-5mm, and grease is smeared on the surface of the steel wire rope 8, so that the steel wire rope is complete in appearance and free of burrs.
The first retainer ring 22 of the embodiment is sleeved at a position which is 0.5m close to the lower end of the round steel pipe body 21; the second retainer ring 23 is sleeved at a position which is 0.5m close to the upper end of the round steel pipe body 21; and the outer diameters of the first retainer ring 22 and the second retainer ring 23 are 30-50 mm.
In this example, the pressure of the injected cement slurry in step S4 and step S6 was 2MPa or more.
The first and second bladder grouting pipes 4 and 7 of the present embodiment are jointless within the borehole 1.
EXAMPLE III
The present embodiment differs from the above embodiments in that: as shown in fig. 2, the guide tube 2 of this embodiment further includes a pointed cone 24, the pointed cone 24 is disposed on the top of the circular steel tube body 21, and the pointed cone 24 and the top of the circular steel tube body 21 are welded and fixed, or may be integrally formed.
The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.