AU2021453348B2 - Method for preventing and controlling rock bursts in development roadway group - Google Patents
Method for preventing and controlling rock bursts in development roadway group Download PDFInfo
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- AU2021453348B2 AU2021453348B2 AU2021453348A AU2021453348A AU2021453348B2 AU 2021453348 B2 AU2021453348 B2 AU 2021453348B2 AU 2021453348 A AU2021453348 A AU 2021453348A AU 2021453348 A AU2021453348 A AU 2021453348A AU 2021453348 B2 AU2021453348 B2 AU 2021453348B2
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- 238000011161 development Methods 0.000 title claims abstract description 126
- 239000011435 rock Substances 0.000 title claims abstract description 62
- 238000000034 method Methods 0.000 title claims abstract description 26
- 238000010276 construction Methods 0.000 claims abstract description 28
- 239000003245 coal Substances 0.000 claims abstract description 25
- 230000002265 prevention Effects 0.000 claims description 9
- 238000007789 sealing Methods 0.000 claims description 6
- 230000001154 acute effect Effects 0.000 claims description 3
- 238000012544 monitoring process Methods 0.000 claims description 2
- 238000012546 transfer Methods 0.000 abstract description 12
- 238000005553 drilling Methods 0.000 abstract description 6
- 230000004048 modification Effects 0.000 description 5
- 238000012986 modification Methods 0.000 description 5
- 230000008569 process Effects 0.000 description 5
- 230000003068 static effect Effects 0.000 description 5
- 230000009471 action Effects 0.000 description 3
- 238000005065 mining Methods 0.000 description 3
- 230000003313 weakening effect Effects 0.000 description 3
- 238000005422 blasting Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 238000004873 anchoring Methods 0.000 description 1
- 238000009412 basement excavation Methods 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 230000000779 depleting effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
- 238000009423 ventilation Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21F—SAFETY DEVICES, TRANSPORT, FILLING-UP, RESCUE, VENTILATION, OR DRAINING IN OR OF MINES OR TUNNELS
- E21F17/00—Methods or devices for use in mines or tunnels, not covered elsewhere
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21C—MINING OR QUARRYING
- E21C41/00—Methods of underground or surface mining; Layouts therefor
- E21C41/16—Methods of underground mining; Layouts therefor
- E21C41/18—Methods of underground mining; Layouts therefor for brown or hard coal
Abstract
The present invention provides a method for preventing and controlling rock bursts in a development roadway group, comprising: analyzing the thickness and strength of each rock layer above the development roadway group, and determining a rock layer whose thickness exceeds a first preset threshold and whose strength exceeds a second preset threshold as a target horizon; determining directional long boreholes of a target number and hole spacing according to a layout range of the development roadway group and a fracturing radius of the directional long boreholes, wherein a directional fracturing range corresponding to the directional long boreholes of the target number and hole spacing may cover the layout range of the development roadway group; carrying out the construction of the target number of directional long boreholes having the corresponding hole spacing from a preselected drilling site to the target horizon; and applying a high pressure to in-hole segments of the directional long boreholes, and using a staged fracturing means to pre-fracture the roof of the development roadway group. In the embodiments of the present invention, the strength and integrity of the roof above a coal seam development roadway group may be effectively reduced, so that an energy transfer changes from a hard transfer to a soft transfer, and the possibility of rock bursts occurring is effectively reduced.
Description
The present disclosure relates to the technical field of safe mining in coal mines, and more
particularly to a rock burst prevention method for a development roadway group.
For large and medium-sized mines with a single near-horizontal coal seam, due to a large area
of a mining field, a group of central roadways (i.e., development roadway groups) is often arranged
during a mine construction period to meet requirements of transportation and ventilation. In order
to shorten a well construction period and put it into production as soon as possible, development
roadways are usually arranged in coal seams, and the influence of factors such as a setting and a
structure of coal pillars in roadways will cause a problem of high stress concentration, which will
lead to the appearance of rock burst, which will have a serious impact on mine safety production,
social harmony and stability.
At present, conventional pressure release measures adopted in coal mine roadways, such as a
coal seam blasting, a large-diameter drilling in coal seam and a deep hole blasting in a top plate, are
often local, and have poor continuity and short pressure relief time. Especially for a group of
roadways, when the pressure is released in this roadway, the pressure will be mistakenly transferred
to adjacent roadways, resulting in the occurrence of rock burst disasters in the adjacent roadways.
Therefore, the rock burst for the roadway group cannot be effectively prevented.
In response to the above problems, the purpose of the present disclosure is to provide a rock
burst prevention method for a development roadway group, which may not only realize the purpose
of regional modification and weakening, but also reduce the strength and integrity of a top plate
above a coal seam development roadway group, so that reduce a concentration degree of dynamic
and static loads induced by the impact and weaken an energy propagation force induced by the
impact, and a possibility of rock burst is effectively reduced.
To realize the above purpose, the present disclosure adopts the following technical solution. A rock burst prevention method for a development roadway group includes analyzing the thickness and strength of each rock stratum above the development roadway group, and determining a rock stratum with the thickness exceeding a first preset threshold and the strength exceeding a second preset threshold as a target horizon; determining, according to an arrangement range of the development roadway group and a fracturing radius of directional long drill holes, a target number and a hole pitch of the directional long drill holes, in which a directional fracturing range corresponding to the directional long drill holes with the target number and the hole pitch can cover the arrangement range of the development roadway group; carrying out construction of the target number of directional long drill holes with the corresponding hole pitch from a pre-selected drill site location to the targeted horizon; and applying high pressure to an interior of the directional long drill hole in a segmented mode, and pre-splitting a top plate of the development roadway group in a segmented fracturing mode.
Alternatively, the present disclosure adopts the following technical solution. A rock burst
prevention method for a development roadway group includes analyzing the thickness and strength
of each rock stratum above the development roadway group, and determining a rock stratum with
the thickness exceeding a first preset threshold and the strength exceeding a second preset threshold
as a target horizon; determining, according to an arrangement range of the development roadway
group and a fracturing radius of directional long drill holes, a target number and a hole pitch of the
directional long drill holes, in which a directional fracturing range corresponding to the directional
long drill holes with the target number and the hole pitch can cover the arrangement range of the
development roadway group; carrying out construction of the target number of directional long drill
holes with the corresponding hole pitch from a pre-selected drill site location to the targeted horizon;
and applying high pressure to an interior of the directional long drill hole in a segmented mode, and
pre-splitting a top plate of the development roadway group in a segmented fracturing mode, wherein
applying high pressure to the interior of the directional long drill hole in the segmented mode, and
pre-splitting the top plate of the development roadway group in the segmented fracturing mode
comprise: installing a packer at a tail end of the directional long drill hole, and applying high pressure
to a hole segment sealed by the packer until the sealed hole segment is successfully fractured with
the high pressure; continuing to sequentially move the packer in a direction toward an orifice of the
directional long drill hole by the preset distance, respectively, until the packer moves to an initial
end of the directional long drill hole in the target horizon, and applying high pressure to the sealed hole segment and fracturing the corresponding hole segment after each movement by the preset distance; wherein an end of the directional long drill hole located in the target horizon far away from the drill site location is defined as the tail end, and an end of the directional long drill hole located in the target horizon near the drill site location is defined as the initial end.
Alternatively, the way of selecting the drill site location includes determining, according to a
layout of the development roadway group and a number of development roadways, a development
roadway located in a middle of the development roadway group; selecting a drill site location at a
safe area far away from an impact hazard area in the middle development roadway; and in which
the drill site location is at a preset distance from a fault location of a coal seam.
Alternatively, before selecting the drill site location at the safe area far away from the impact
hazard area in the middle development roadway, the method further including acquiring impact
factors of a rock burst of the development roadway group, and dividing the impact hazard area of
the development roadway group based on the impact factors of the rock burst; or monitoring an
appearance position of the rock burst, and determining the impact hazard area of the development
roadway group according to the appearance position of the rock burst.
Alternatively, carrying out construction of the target number of the directional long drill holes
with the corresponding hole pitch from the pre-selected drill site location to the targeted horizon
includes extending construction of the target number of the directional long drill holes toward the
target horizon in different directions, starting from a top plate of a development roadway to which
the pre-selected drill site location belongs, and making individual directional long drill holes
extended into the target horizon have the corresponding hole pitch; and carrying out construction of
each directional long drill hole in the target horizon in a length direction of the development roadway.
Alternatively, extending construction of the target number of the directional long drill holes
toward the target horizon in different directions, starting from the top plate of the development
roadway to which the pre-selected drill site location belongs includes extending the construction of
the target number of the directional long drill holes toward the target horizon in different directions
at an acute angle to a floor of the development roadway, starting from the top plate of the
development roadway to which the pre-selected drill site location belongs.
Alternatively, applying high pressure to the interior of the directional long drill hole in the
segmented mode, and pre-splitting the top plate of the development roadway group in the segmented
fracturing mode include installing a packer at a tail end of the directional long drill hole, and applying high pressure to a hole segment sealed by the packer until the sealed hole segment is successfully fractured with the high pressure; continuing to sequentially move the packer in a direction toward an orifice of the directional long drill hole by the preset distance, respectively, until the packer moves to an initial end of the directional long drill hole in the target horizon, and applying high pressure to the sealed hole segment and fracturing the corresponding hole segment after each movement by the preset distance; and in which an end of the directional long drill hole located in the target horizon far away from the drill site location is defined as the tail end, and an end of the directional long drill hole located in the target horizon near the drill site location is defined as the initial end.
Alternatively, the preset distance is a sealing length of the packer, or a specified distance greater
than the sealing length of the packer.
Alternatively, the first preset threshold corresponding to the thickness of the rock stratum is 6m,
and the second preset threshold corresponding to the strength of the rock stratum is 60MPa.
With the above technical solution, the present disclosure has the following advantages. An
embodiment of the present disclosure determines the target horizon to be fractured based on the
thickness and strength of each rock stratum above the development roadway group, after
determining, according to the arrangement range of the development roadway group and the
fracturing radius of directional long drill holes, the target number and the hole pitch of the directional
long drill holes, and then may carry out construction of the target number of directional long drill
holes with the corresponding hole pitch from the pre-selected drill site location to the targeted
horizon, and by applying high pressure to the interior of the directional long drill hole in the
segmented mode, the top plate of the development roadway group may be pre-split in the segmented
fracturing mode. Therefore, the embodiment of the present disclosure regionally arranges directional
long drill holes on the top plate of the development roadway group, and the top plate above the
development roadway of the coal seam is pre-fractured in a one-time, large-scale and continuous
way through the arranged directional long drill holes, which may not only realize the purpose of
regional modification and weakening, but also reduce the strength and integrity of the top plate
above the development roadway of the coal seam, so that reduce a concentration degree of dynamic
and static loads induced by the impact and weaken an energy propagation force induced by the
impact. On the one hand, it may release an accumulated energy of the rock stratum, and on the other
hand, it may form a "soft" structure above the protected development roadway, so that an energy transfer changes from a hard transfer to a soft transfer, and a possibility of the rock burst occurring is effectively reduced.
FIG. 1 is a flow chart showing a rock burst prevention method for a development roadway
group according to an embodiment of the present disclosure.
FIG. 2 is a schematic cross section showing a directional long drill hole according to an
embodiment of the present disclosure.
FIG. 3 is a schematic diagram showing a directional long drill hole and fracturing according to
an embodiment of the present disclosure.
FIG. 4 is a schematic side view showing a directional long drill hole according to an
embodiment of the present disclosure.
A preferred embodiment of the present disclosure will be described in detail below in
combination with accompanying drawings for a clearer understanding of the purposes, features and
advantages of the present disclosure. It should be understood that embodiments shown in the
accompanying drawings are not intended to limit the scope of the present disclosure, but only to
illustrate the substantial spirit of technical solutions of the present disclosure.
In order to solve the above technical problems, an embodiment of the present disclosure provide
a rock burst prevention method for a development roadway group. FIG. 1 shows a flow chart
showing a rock burst prevention method for a development roadway group according to an
embodiment of the present disclosure. Referring to FIG. 1, a rock burst prevention method for a
development roadway group includes steps S102 to S108.
In step S102, the thickness and strength of each rock stratum above the development roadway
group are analyzed, and a rock stratum with the thickness exceeding a first preset threshold and the
strength exceeding a second preset threshold is determined as a target horizon.
In step S104, according to an arrangement range of the development roadway group and a
fracturing radius of the directional long drill holes, a target number and a hole pitch of the directional
long drill holes are determined, in which a directional fracturing range corresponding to the
directional long drill holes with the target number and the hole pitch can cover the arrangement range of the development roadway group.
The number of directional long drill holes determined in an embodiment shown in FIG. 2 is
five, which are a first directional long drill hole 1, a second directional long drill hole 2, a third
directional long drill hole 3, a fourth directional long drill hole 4, and a fifth directional long drill
hole 5, respectively. This number is merely schematic and does not limit the solution of the present
disclosure.
In step S106, construction of the target number of directional long drill holes with the
corresponding hole pitch is carried out from a pre-selected drill site location to the targeted horizon.
In step S108, high pressure is applied to an interior of the directional long drill hole in a
segmented mode, and a top plate of the development roadway group is pre-split in a segmented
fracturing mode.
According to an embodiment of the present disclosure, the directional long drill holes are
regionally arranged on the top plate of the development roadway group, and the top plate above the
development roadway of the coal seam is pre-fractured in a one-time, large-scale and continuous
way through the arranged directional long drill holes, which may not only realize the purpose of
regional modification and weakening, but also reduce the strength and integrity of the top plate
above the development roadway group of the coal seam, so that reduce a concentration degree of
dynamic and static loads induced by the impact and weaken an energy propagation force induced by
the impact. On the one hand, it may release an accumulated energy of the rock stratum, and on the
other hand, it may form a "soft" structure above the protected development roadway, so that an
energy transfer changes from a hard transfer to a soft transfer, and a possibility of the rock burst
occurring is effectively reduced.
Referring to step S102 above, in an alternative embodiment of the present disclosure, the first
preset threshold corresponding to the thickness of the rock stratum is 6m, and the second preset
threshold corresponding to the strength of the rock stratum is 60MPa. An embodiment of the present
disclosure may determine a rock stratum with the thickness of more than 6m and the strength of
more than 60MPa as the target horizon, which is a main horizon affecting the occurrence of the rock
burst. The embodiment of the present disclosure does not specifically limit the first preset threshold
and the second preset threshold.
The embodiment of the present disclosure may analyze the thickness and strength of each rock
stratum above the development roadway group according to geological data of a mine, and then determine the target horizon according to the analyzed thickness and strength of each rock stratum above the development roadway group. For example, the target horizon determined according to the thickness and strength of each rock stratum in an embodiment of the present disclosure is a silt layer with a thickness of 20.9m, i.e., the silt layer with the thickness of 20.9m may be pre-fractured. FIG.
2 shows the thickness of each rock stratum. Of course, other hard and thick layer top plates may also
be selected as the target horizon, which is not specifically defined by the embodiment of the present
disclosure.
In an embodiment of the present disclosure, with reference to FIG. 2 and FIG. 3, it is assumed
that the development roadway group includes five development roadways, which are a first
development roadway 8, a second development roadway 9, a third development roadway 10, a fourth
development roadway 11, and a fifth development roadway 12, respectively. The width of coal
pillars between roadway of each development roadway is 35m, the width of the reserved coal pillars
is small. After roadway excavation, a level of concentrated static load is relatively high. The effects
of dynamic and static loads on Xiejiazui anticline, Yuankouzi syncline, and DF29 fault are
superimposed, and a stress concentration degree is greatly increased. Under this condition, compared
with a non-structural area, there is a high risk of impact in a complex structure area of a development
roadway, and the impact appears frequently. The anticline refers to an upward convex position of a
shape when a rock stratum is folded. The synclines are one of basic forms of folds, as opposed to
the anticlines.
Therefore, according to the target number and the hole pitch of the directional long drill holes
determined in step S104 above, the construction of the target number of directional long drill holes
with the corresponding hole pitch may be carried out from the pre-selected drill site location to the
targeted horizon, so that a directional fracturing range corresponding to the arrangement of the target
number and the corresponding hole pitch of the directional long drill holes may effectively cover an
arrangement range of the development roadway group.
In an embodiment of the present disclosure, a fracture radius of the directional long drill hole
may be determined according to parameters such as a pressure and a rock stratum that are
subsequently applied by the directional long drill hole. For example, in an embodiment of the present
disclosure, a fracture radius of the directional long drill hole is about 30m. The criteria for
determining, according to the arrangement range of the development roadway group and the
fracturing radius of the directional long drill holes, the target number and the hole pitch of the directional long drill holes is to ensure that the directional fracturing range corresponding to the directional long drill holes with the target number and the corresponding hole pitch may effectively cover the arrangement range of the development roadway group, that is, the directional long drill holes arranged according to the target number and the corresponding hole pitch may ensure that the top plate is pre-split without blind area. For example, according to the arrangement range of the development roadway group and the fracture radius of the directional long drill holes, the target number of the directional long drill holes is determined as 5, namely the first directional long drill hole 1, the second directional long drill hole 2, the third directional long drill hole 3, the fourth directional long drill hole 4, and the fifth directional long drill hole 5 in FIGS. 2 and 3, respectively. The determined hole pitch is that a hole pitch between two adjacent directional long drill holes in the first directional long drill hole 1 to the fourth directional long drill hole 4 is about 40m, and a hole pitch between the fourth directional long drill hole 4 and the fifth directional long drill hole 5 is about 70m, respectively. According to a layout of the hole pitch, the directional fracturing range corresponding to the five directional long drill holes may well cover the arrangement range of the development roadway group. Referring to FIG. 3, in an embodiment of the present disclosure, after drilling construction, the first directional long drill hole 1, the second directional long drill hole 2, the third directional long drill hole 3, and the fourth directional long drill hole 4 are located above coal pillars of a segment between development roadways, respectively, and the hole pitch is about 40m. The fifth directional long drill hole 5 is located above a protective coal pillar of the roadway, and the hole pitch of the fourth directional long drill hole 4 and the fifth directional long drill hole 5 is about 70m. In an embodiment of the present disclosure, one end of the directional long drill hole located in the target horizon far away from the drill site location is at a specified distance from the fault. For example, a distance range of the specified distance may be 1Om to 20m. For example, the hole length of the first long directional drill hole 1 is 570m, the hole length of the second long directional drill hole 2 is 495m, the hole length of the third long directional drill hole 3 is 420m, the hole length of the fourth long directional drill hole 4 is 370m, the hole length of the fifth long directional drill hole is 260m. In an embodiment of the present disclosure, referring to FIGS. 2 and 3, in a process of performing step S106 to carry out construction of the target number of the directional long drill holes with the corresponding hole pitch from the pre-selected drill site location to the targeted horizon.
Starting from a top plate of a development roadway to which a pre-selected drill site 7 belongs, the
construction of the target number of the directional long drill holes may be extended toward the
target horizon in different directions, and each directional long drill hole extending into the targeted
horizon has a corresponding hole pitch, such as the hole pitch between each directional long drill
hole described in the above embodiment. Furthermore, after the directional long drill hole is
extended into the target horizon, the construction of each directional long drill hole is carried out in
the target horizon in the length direction of the development roadway. According to the embodiment
of the present disclosure, the corresponding directions in a construction process of extending to the
target horizon in different directions are not specifically limited, so that the pitch of each directional
long drill hole may be ensured to be equal to the corresponding hole pitch previously determined
after each directional long drill hole reaches the target horizon.
In the embodiment, referring to FIG. 4, starting from the top plate of the development roadway
to which the pre-selected drill site 7 belongs, the construction of the target number of the directional
long drill holes may be extended toward the target horizon in different directions at an acute angle
to a floor of the development roadway, so that the transition of the directional long drill holes from
the top plate of the development roadway to the target horizon is more smooth, and facilitate the
construction process of the directional long drill holes.
In the embodiment of the present disclosure, after the directional long drill holes extend to the
target horizon and the construction of each directional long drill hole is carried out in the target
horizon in a length direction of the development roadway, the directional long drill holes in the target
horizon are at a height of 45m above the top plate of the development roadway, and of course, other
heights are possible.
In the embodiment of the present disclosure, for the target number of directional long drill holes,
a drilling operation of each directional long drill hole may be carried out simultaneously. For
example, there are five directional long drill holes, drilling operations may be carried out for five
directional long drill holes at the same time to improve the efficiency of the drilling operations.
In an embodiment of the present disclosure, the way of pre-selecting the drill site location may
be as follows. Firstly, according to a layout of the development roadway group and a number of
development roadways, a development roadway located in a middle of development roadway group
is determined. Then, a drill site location is selected at a safe area far away from an impact hazard
area in the determined middle development roadway. The embodiment of the present disclosure may set the drill site 7 at a preset distance from a fault location of a coal seam. Combined with FIG. 2 and FIG. 3, if the development roadway group includes five development roadways, namely, a first development roadway 8, a second development roadway 9, a third development roadway 10, a fourth development roadway 11, and a fifth development roadway 12, respectively. It may be determined that the third development roadway 10 is located in the middle of the development roadway group, and the third development roadway 10 may be referred to herein as a central development roadway. Then, the drill site location is selected at the safe area far away from the impact hazard area in the third development roadway 10, and the drill site 7 is 480m away from the fault location of the coal seam. In the embodiment, the distance between the drill site 7 and the fault location of the coal seam may also be other distances, which is not specifically limited by the embodiment of the present disclosure. The embodiment of the present disclosure selects the drill site location at the safe area far away from the impact hazard area, which may make the construction personnel in the safe area. In an embodiment of the present disclosure, it is also necessary to determine the impact hazard area before selecting the drill site location at the safe area far away from the impact hazard area in the middle development roadway. There are two ways to determine the impact hazard area in the embodiment of the present disclosure. The first one is to acquire impact factors of a rock burst of the development roadway group firstly, and then divide the impact hazard area of the development roadway group based on the impact factors of the rock burst. The impact factors of the rock burst may include at least one of a mining depth, physical and mechanical properties of coal and rock mass, a thickness of a coal seam, a top plate rock stratum structure, a geological structure, and a width of a coal pillar. The other one is to monitor an appearance position of the rock burst, and then determine the impact hazard area of the development roadway group according to the monitored appearance position of the rock burst. Referring to step S108 above, in an embodiment of the present disclosure, a process of applying high pressure to the interior of the directional long drill hole in the segmented mode, and pre-splitting the top plate of the development roadway group in the segmented fracturing mode specifically includes the following contents. Firstly, a packer is installed at a tail end of the directional long drill hole, and applying high pressure to a hole segment sealed by the packer until the sealed hole segment is successfully fractured with the high pressure. Then, the packer is moved in a direction toward an orifice of the directional long drill hole by the preset distance, and high pressure is applied to the sealed hole segment until the corresponding hole segment is fractured. Then, the packer is again moved in a direction toward the orifice of the directional long drill hole by the preset distance, and high pressure is applied to the sealed hole segment until the corresponding hole segment is fractured, and so on, until the directional long drill hole in the target horizon is completely fractured. In other words, sequentially the packer is moved in a direction toward the orifice of the directional long drill hole by the preset distance, respectively, until the packer moves to an initial end of the directional long drill hole in the target horizon, and high pressure is applied to the sealed hole segment and the corresponding hole segment is fractured after each movement by the preset distance.
In the embodiment, an end of the directional long drill hole located in the target horizon far
away from the drill site location is defined as the tail end, and an end of the directional long drill
hole located in the target horizon near the drill site location is defined as the initial end, and an
opening of the directional long drill hole connected with the development roadway is an orifice of
the directional long drill hole.
In the embodiment of the present disclosure, the preset distance of each movement may be a
sealing length of the packer. For example, each fracture hole segment in each directional long drill
hole shown in FIG. 3 is adjacent to each other, such as a hole segment 6 of the first directional long
drill hole 1. The preset distance of each movement may also be a specified distance greater than the
sealing length of the packer, that is, each fracture hole segment in each directional long drill hole is
not adjacent to each other, which is not specifically limited by the embodiment of the present
disclosure. Of course, in a process of pre-fracturing, not only the packer is used, but also tools such
as a ball throwing safety joint, a differential pressure opening sliding sleeve and a setting ball seat
are lowered into the directional long drill hole, which is not limited by the embodiment of the present
disclosure.
The packer of the embodiment of the present disclosure may adopt a bi-directional anchoring
expanding bare eye packer, and a way to apply high pressure to the hole segment sealed by the
packer may be to inject high pressure water into the sealed hole segment, so as to form a high
pressure state in the sealed hole segment. Therefore, the embodiment of the present disclosure adopts
a backward segmental hydraulic fracturing method to pre-fracture the top plate, forming a complex
seam net in the target rock stratum, reducing the strength and integrity of the top plate. On the one
hand, it may release the accumulated energy, and on the other hand, it may form a "soft" structure above the protected development roadway, so that an energy transfer changes from a hard transfer to a soft transfer, depleting the energy transmission, reduce a level of stress concentration, thus reducing the central roadway impact hazard.
It is to be noted that for the sake of simple description, all the above-mentioned method
embodiments are expressed as a series of action combinations, but those skilled in the art will
appreciate that the present disclosure is not limited by the sequence of actions described, as some
steps may occur in other orders or concurrently with other acts from that described herein. Secondly,
those skilled in the art will appreciate that the embodiments described in the description are
alternative embodiments, and the actions involved are not necessarily necessary for the present
disclosure.
Finally, it is to be noted that above embodiments are only used to illustrate the technical solution
of the present disclosure, but not to limit it. Although the present disclosure has been described in
detail with reference to the above-mentioned embodiments, it is to be understood by those skilled in
the art that it is still possible to modify the technical solutions described in the above-mentioned
embodiments, or to equivalently replace some technical features thereof. These modifications or
substitutions do not make the essence of the corresponding technical solutions depart from the spirit
and scope of the technical solutions of various embodiments of the present disclosure.
In the claims which follow and in the preceding description of the invention, except where the
context requires otherwise due to express language or necessary implication, the word "comprise"
or variations such as "comprises" or "comprising" is used in an inclusive sense, i.e. to specify the
presence of the stated features but not to preclude the presence or addition of further features in
various embodiments of the invention.
It is to be understood that, if any prior art publication is referred to herein, such reference does
not constitute an admission that the publication forms a part of the common general knowledge in
the art, in Australia or any other country.
It will be understood to persons skilled in the art of the invention that many modifications may
be made without departing from the spirit and scope of the invention.
Claims (7)
1. A rock burst prevention method for a development roadway group, characterized by
comprising:
analyzing the thickness and strength of each rock stratum above the development roadway
group, and determining a rock stratum with the thickness exceeding a first preset threshold and the
strength exceeding a second preset threshold as a target horizon;
determining, according to an arrangement range of the development roadway group and a
fracturing radius of directional long drill holes, a target number and a hole pitch of the directional
long drill holes, wherein a directional fracturing range corresponding to the directional long drill
holes with the target number and the hole pitch can cover the arrangement range of the development
roadway group;
carrying out construction of the target number of directional long drill holes with the
corresponding hole pitch from a pre-selected drill site location to the targeted horizon; and
applying high pressure to an interior of the directional long drill hole in a segmented mode, and
pre-splitting a top plate of the development roadway group in a segmented fracturing mode;
wherein applying high pressure to the interior of the directional long drill hole in the segmented
mode, and pre-splitting the top plate of the development roadway group in the segmented fracturing
mode comprise:
installing a packer at a tail end of the directional long drill hole, and applying high pressure to
a hole segment sealed by the packer until the sealed hole segment is successfully fractured with the
high pressure;
continuing to sequentially move the packer in a direction toward an orifice of the directional
long drill hole by the preset distance, respectively, until the packer moves to an initial end of the
directional long drill hole in the target horizon, and applying high pressure to the sealed hole segment
and fracturing the corresponding hole segment after each movement by the preset distance;
wherein an end of the directional long drill hole located in the target horizon far away from the
drill site location is defined as the tail end, and an end of the directional long drill hole located in the
target horizon near the drill site location is defined as the initial end.
2. The method of claim 1, characterized in that the way of selecting the drill site location
comprises:
determining, according to a layout of the development roadway group and a number of development roadways, a development roadway located in a middle of the development roadway group; selecting a drill site location at a safe area far away from an impact hazard area in the middle development roadway; and wherein the drill site location is at a preset distance from a fault location of a coal seam.
3. The method of claim 2, characterized by before selecting the drill site location at the safe area far away from the impact hazard area in the middle development roadway, further comprising: acquiring impact factors of a rock burst of the development roadway group, and dividing the impact hazard area of the development roadway group based on the impact factors of the rock burst; or monitoring an appearance position of the rock burst, and determining the impact hazard area of the development roadway group according to the appearance position of the rock burst.
4. The method of any one of claims I to 3, characterized in that carrying out construction of the target number of the directional long drill holes with the corresponding hole pitch from the pre selected drill site location to the targeted horizon comprises: extending construction of the target number of the directional long drill holes toward the target horizon in different directions, starting from a top plate of a development roadway to which the pre selected drill site location belongs, and making individual directional long drill holes extended into the target horizon have the corresponding hole pitch; and carrying out construction of each directional long drill hole in the target horizon in a length direction of the development roadway.
5. The method of claim 4, characterized in that extending construction of the target number of the directional long drill holes toward the target horizon in different directions, starting from the top plate of the development roadway to which the pre-selected drill site location belongs comprises: extending the construction of the target number of the directional long drill holes toward the target horizon in different directions at an acute angle to a floor of the development roadway, starting from the top plate of the development roadway to which the pre-selected drill site location belongs.
6. The method of any one of claims I to 5, characterized in that the preset distance is a sealing length of the packer, or a specified distance greater than the sealing length of the packer.
7. The method of any one of claims 1 to 6, characterized in that the first preset threshold corresponding to the thickness of the rock stratum is 6m, and the second preset threshold corresponding to the strength of the rock stratum is 60MPa.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110727990.9A CN113236360A (en) | 2021-06-29 | 2021-06-29 | Method for preventing and controlling exploding roadway group rock burst |
| CN202110727990.9 | 2021-06-29 | ||
| PCT/CN2021/129996 WO2023273091A1 (en) | 2021-06-29 | 2021-11-11 | Method for preventing and controlling rock bursts in development roadway group |
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| AU2021453348A1 AU2021453348A1 (en) | 2023-03-23 |
| AU2021453348B2 true AU2021453348B2 (en) | 2024-02-29 |
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| AU2021453348A Active AU2021453348B2 (en) | 2021-06-29 | 2021-11-11 | Method for preventing and controlling rock bursts in development roadway group |
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| CN (1) | CN113236360A (en) |
| AU (1) | AU2021453348B2 (en) |
| WO (1) | WO2023273091A1 (en) |
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| CN113236360A (en) * | 2021-06-29 | 2021-08-10 | 中煤科工开采研究院有限公司 | Method for preventing and controlling exploding roadway group rock burst |
| CN113339065B (en) * | 2021-06-29 | 2024-02-02 | 中煤科工开采研究院有限公司 | Method for preventing and controlling rock burst of multi-coal pillar stoping roadway along air |
| CN114856564A (en) * | 2022-04-15 | 2022-08-05 | 中煤科工开采研究院有限公司 | Rock burst coal seam roadway anti-scour pressure-relief tunneling method |
| CN115288681A (en) * | 2022-08-03 | 2022-11-04 | 中煤科工开采研究院有限公司 | Method for preventing rock burst at fracture source in coal mine roof area |
| CN116050171B (en) * | 2023-02-08 | 2024-03-08 | 中煤科工开采研究院有限公司 | Anti-impact method for artificial liberation layer of tunneling roadway |
| CN116122811A (en) * | 2023-02-21 | 2023-05-16 | 中煤科工开采研究院有限公司 | Rock burst pressure relief method for large roadway area |
| CN117217400A (en) * | 2023-11-09 | 2023-12-12 | 中煤科工集团北京华宇工程有限公司 | Mine disaster avoidance route planning method and device, electronic equipment and storage medium |
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| TR200700926T1 (en) * | 2004-08-17 | 2007-05-21 | Sesqui Mining Llc | Methods for underground well configurations and related solution mining methods |
| CN106907175B (en) * | 2017-05-02 | 2019-06-04 | 中国矿业大学 | The efficient extraction coal roadway stripe gas of bottom plate concordant long drilled holes staged fracturing and region outburst elimination method |
| CN107013216A (en) * | 2017-05-16 | 2017-08-04 | 中国科学院武汉岩土力学研究所 | A kind of colliery deep mining impulsion pressure prevention and controls |
| CN108386192A (en) * | 2018-01-31 | 2018-08-10 | 中国矿业大学 | A kind of method of active Enhanced support and active release prevention bump |
| CN110130897A (en) * | 2019-06-13 | 2019-08-16 | 中国神华能源股份有限公司 | Roof weakening solution danger method |
| CN111270987B (en) * | 2020-01-20 | 2020-12-25 | 中国矿业大学 | Method for accurately preventing and controlling rock burst in remote area under coal mine |
| CN111271120A (en) * | 2020-01-22 | 2020-06-12 | 天地科技股份有限公司 | Coal mine rock burst dynamic and static load source-based danger relieving method |
| CN111322048B (en) * | 2020-02-21 | 2021-11-09 | 中煤科工集团西安研究院有限公司 | Hard roof rock burst subsection direction-control fracturing treatment method |
| CN111255463B (en) * | 2020-02-21 | 2021-06-22 | 中煤科工集团西安研究院有限公司 | Hard top plate comb-shaped long drilling segmented fracturing roadway deformation source treatment method |
| CN113236360A (en) * | 2021-06-29 | 2021-08-10 | 中煤科工开采研究院有限公司 | Method for preventing and controlling exploding roadway group rock burst |
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- 2021-06-29 CN CN202110727990.9A patent/CN113236360A/en active Pending
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| CN113236360A (en) | 2021-08-10 |
| WO2023273091A1 (en) | 2023-01-05 |
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