TECHNICAL FIELD
[0001] The present disclosure relates to a coal seam mining method, and particularly to
a longwall working face coal seam mining method.
BACKGROUND
[0002] With the increased depth of coal mining, a longwall mining usually adopts means of
retaining pillars to protect a tailentry roadway. In the case of a relatively deep
roadway, the widths of retained pillars are increased due to the rapidly increased
ground stress. In the goaf-side entry retaining (driving) mining process of the traditional
longwall mining method, large engineering quantity of roadways, high development ratio,
low production efficiency, severe resource waste in the deep mining process, and safety
hazards such as gas outbursts, frequent rock bursts and air leakage in the goafs caused
by the retained pillars, have become important problems that are disturbing and affecting
mine safety and efficiency.
[0003] At present, the research on non-pillared mining in main mining countries domestically
and abroad mainly focuses on two aspects: goaf-side entry driving and goaf-side entry
retaining. Goaf-side entry driving refers to the following: after the previous working
face extracting is completed, a top panel of the mining face is fully caved, waste
rocks are extruded and compacted, the behaviors of the ground pressure in cover rocks
stop, and surrounding rocks are stable, a pressure relief zone is formed in the goaf
and the edge of coal mass, and a new roadway is driven again in the pressure relief
zone. In the goaf-side entry driving, entry driving can only be performed after a
working face of the previous district sublevel extracting is completed and the top
panel of the mining face is completely caved and compacted, and hence a long time
is required, thereby resulting in difficult production replacement of many mines in
China.
[0004] Goaf-side entry retaining refers to the following: in the extracting process of the
working face, a headentry in the working face is retained by relevant technology and
taken as a tailentry for extracting of the next working face. In the current goaf-side
entry retaining technology, in the aspect of roadway inner support, technology such
as wooden shed, I-shaped steel shed, telescopic support and bolt mesh anchor has been
developed in succession. In the aspect of roadway side support, technology such as
timber crib, dense pillar, waste pack, concrete block, paste backfilling and high-water-content
material refilling has been developed. Despite some achievements, there are still
many deficiencies and problems: the supporting function of a roadway side coal mass
is ignored; there are few applications for active roadway support technology; the
roadway side support and the surrounding rock deformation are uncoordinated; and the
support design is not systematic.
[0006] US 5,668,325 discloses an apparatus for determining compressive stress in an in-situ roof support
pillar.
SUMMARY
[0007] The objective of the present disclosure is to overcome the defects in the prior art
and provide a longwall working face non-pillared mining method having advantages of
reliable support, high mining efficiency and no requirement of pillars.
[0008] In order to achieve the objective of the present disclosure, the present disclosure
provides a longwall working face non-pillared mining method, includes steps of:
- i) excavating two communicated roadways on a coal seam as a tailentry and a headentry
of a first mining face;
- ii) reinforcing a top panel of the headentry and drilling on the working face side
of the top panel of the headentry a plurality of energy collecting holes for pre-splitting
blasting;
- iii) extracting until a goaf is formed, and the roadway is eliminated;
- iv) blasting at a position corresponding to the energy collecting holes on the top
panel of the original headentry of the goaf, and forming a directional kerf, extending
up and down along the entire original headentry, on a side of the top panel close
to the mining face;
- v) making the top panel of the mining face collapse by the pressure from a deep stratum
on an upper portion of the goaf, and forming a new roadway at a position of the original
headentry;
- vi) taking the roadway, automatically formed at the position of the original headentry,
as a tailentry of a next mining face, and excavating a headentry relative to the tailentry,
to form a new mining face; and
- vii) repeating steps ii) to vi), and continuing to mine coal until coal seam mining
is completed.
[0009] In order to further achieve the objective of the present disclosure, step ii) further
includes steps of: mounting a sensor on the top panel of the headentry, and wire-transmitting
signals to the ground for remotely real-time monitoring of the status of the headentry.
An anchor rod with constant resistance and large deformation is adopted in the step
ii) to reinforce the top panel of the headentry. A bidirectional energy collecting
pre-splitting blasting method is adopted in the step iv) to perform a directional
kerfing. In the steps i) and vi), the roadways need also to be subjected to leakproof
and fireproof treatments. The sensor in the step ii) includes a top panel separation
indicator and an anchor rod stress analyzer.
[0010] Compared with the prior art, the longwall working face non-pillared mining method
provided by the present disclosure has one or more of the following prominent substantive
features and notable progresses. In the longwall working face non-pillared mining
method provided by the present disclosure, the energy collecting holes for pre-splitting
blasting are drilled on the working face side of the top panel of the headentry; blasting
is performed at the position corresponding to the energy collecting hole; the kerf
extending along the original headentry is formed on a side of the top panel close
to the mining face; the goaf is caved along the kerf, so that the roadway can be automatically
formed at the position of the original headentry; the top panel of the roadway cannot
be affected by goaf carving and can be kept in good state; then the roadway is taken
as a tailentry of the next mining face, and the next mining process is performed continuously;
and every two mining faces are continuous and not supported by pillars. Therefore,
compared with the prior art, the longwall working face non-pillared mining method
has prominent substantive features. In addition, the longwall working face non-pillared
mining method provided by the present disclosure achieves the objective of non-pillared
support and high coefficient of mining. Moreover, as long term is not required in
the roadway forming process, the time of continuous coal seam mining can be reduced
under the premise of safety, and hence the longwall working face non-pillared mining
method provided by the present disclosure has significant progress compared with the
prior art.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011]
FIG. 1 is a schematic structural top view of a mining face in a longwall working face
non-pillared mining method provided by the present disclosure;
FIG. 2 is a schematic structural front view of the mining face in the longwall working
face non-pillared mining method provided by the present disclosure;
FIG. 3 is a schematic structural view illustrating the reinforcement and drilling
of a headentry of a first mining face in the longwall working face non-pillared mining
method provided by the present disclosure;
FIG. 4 is a schematic structural view illustrating the process of forming a goaf on
the first mining face in the longwall working face non-pillared mining method provided
by the present disclosure;
FIG. 5 is a schematic structural view illustrating the process of goaf carving in
the longwall working face non-pillared mining method provided by the present disclosure;
and
FIG. 6 is a schematic structural view of an anchor rod with constant resistance and
large deformation in the longwall working face non-pillared mining method provided
by the present disclosure.
[0012] Reference numerals in the accompanying drawings: 1 - first mining face, 2 - tailentry,
3 - headentry, 4 - extracting face, 5 - top panel, 6 - anchor rod with constant resistance
and large deformation, 7 - energy collecting hole, 61 - nut, 62 - ball pad, 63 - tray,
64 - constant-resistance device, 65 - connecting sleeve, 66 - rod body.
DETAILED DESCRIPTION
[0013] Detailed description will be given below to the specific structural details and the
installation and use process of a sludge discharge pipe floating body provided by
the present disclosure.
[0014] In the non-pillared mining method provided by the present disclosure, a first mining
face needs to be formed at first. As illustrated in FIGS. 1 and 2, the method for
forming the first mining face 1 is the same as the traditional method including steps
of: determining a primary mining position on a mining edge of a coal seam, and excavating
two parallel roadways 2 and 3 at the position by an S100A roadheader. The two parallel
roadways 2 and 3 are communicated with each other at the tails through a roadway 4.
The roadway 2 close to the edge is a tailentry; the roadway 3 close to the next mining
face is a headentry; and the roadway for communicating the tailentry 2 and the headentry
3 is an extracting face 4. Each mining face must be provided with two roadways; the
tailentry is a material delivery roadway; and the headentry is an air return roadway.
In actual mining, the mining process begins from the extracting face 4 until all the
coals in areas between the tailentry 2 and the headentry 3 are worked out, and then
the next mining face is mined.
[0015] Subsequently, as illustrated in FIG. 3, the headentry 3 of the first mining face
1 is supported. The supporting process includes passive support and active support.
The passive support is to set up a frame in the headentry 3, and the frame passively
bears the pressure from a top panel of the headentry 3. The supporting means has the
defects of high material consumption, high cost and limited supporting effect. The
active support is to additionally arrange an anchor rod on the top panel 5 of the
headentry 3 to reinforce the top panel 5. The anchor rod 6 is usually 5 to 10 m in
length and prop the top panel 5 of the headentry 3 by being connected with a relatively
stable rock mass on an upper layer. The common anchor rod has a small deformation
and can be easily broken. An anchor rod with constant resistance and a large deformation
is adopted for reinforcement in the present disclosure. The anchor rod with constant
resistance and a large deformation has been disclosed in detail in the patent publication
document
CN101858225B. The anchor rods with constant resistance and large deformation 6 are uniformly distributed
on the top panel 5 of the headentry 3 of the first mining face 1, and the spacing
is set to be 2 to 5 m as required.
[0016] As illustrated in FIG. 6, the anchor rod with constant resistance and large deformation
6 is an anchor rod designed for large-deformation roadways and high-stress roadways,
where the constant resistance can be maintained and the elongation is maintained by
a mechanical slide means. The anchor rod with constant resistance and large deformation
6 includes a nut 61, a ball pad 62, a tray 63, a constant-resistance device 64, a
connecting sleeve 65 and a rod body 66. The constant-resistance device 64 has a cylindrical
structure and is sleeved at the tail of the rod body 66; the tray 63 and the nut 61
are sleeved at the tail of the constant-resistance device 64 in sequence; a central
portion of the tray 63 is provided with a hole through which the constant-resistance
device 64 passes; the nut 61 is in a threaded connection with the constant-resistance
device 64; the ball pad 62 for buffer is disposed between the nut 61 and the tray
63; and the connecting sleeve is disposed at the other end of the constant-resistance
device 64.
[0017] When the anchor rod with constant resistance and large deformation 6 is applied to
a roadway, if the deformation of surrounding rocks of the roadway exceeds the bearing
range of the anchor rod, a relative displacement is generated by the rod body 66 of
the anchor rod and the constant-resistance device 64 provided with threaded structures
on junction surfaces thereof, namely the anchor rod 6 is subjected to a large deformation
representing a radial extension as the large deformation of the surrounding rocks.
After the large deformation of the surrounding rocks, the energy thereof is released,
but the anchor rod with constant resistance and large deformation 6 can still maintain
constant working resistance after extension; when the deformation energy of the surrounding
rocks is less than the constant working resistance of the anchor rod with constant
resistance and large deformation 6, and the constant-resistance device 64 is restored
and tightly sleeved on the rod body 66, the roadway is in a stable state again, and
hence the stability of the roadway can be achieved and the safety hazards such as
the impact of the top panel falling can be eliminated. The bearing capacity of the
anchor rod with constant resistance and large deformation 6 is in a range of 15 to
20 KN and the elongation thereof can reach 300 to 600 mm. Therefore, the anchor rod
with constant resistance and large deformation 6 has a large deformability so as to
be adapted to the high deformability of goaf roadways.
[0018] In addition, energy collecting holes 7 linearly arranged are drilled up on the top
panel 5 of the headentry 3 of the first mining face 1, close to a side of the first
mining face, in sequence by an MQT-120J drill, so that the blasting process can be
conveniently achieved by the energy collecting holes 7 and hence the directional kerf
can be achieved. The pitch of the energy collecting holes 7 is 2 to 5 m and determined
by the characteristics of actual strata. Meanwhile, the roadways 2, 3 and 4 need also
to be sprayed with urea-formaldehyde polystyrene foam for leakage resistance and fire
resistance.
[0019] In the present disclosure, a top panel separation indicator and an anchor rod stress
analyzer are also disposed on the top panel 5 of the headentry 3 of the first mining
face, and shape and position sensors may be also mounted at a corresponding position
of the side wall and bottom surface of the headentry 3. The top panel separation indicator
is mounted on the top panel 5 and can detect the variation of the relative displacement
of a determined near point relative to a determined far point, so as to monitor the
fall state of the top panel 5; the anchor rod stress analyzer is mounted on the top
panel 5 through the anchor rod 6 and can detect the pressure of the top panel 5 on
a top face of the tray 63 of the anchor rod with constant resistance and large deformation
6, so as to monitor the variation of the fall pressure of the top panel 5; and the
shape and position sensors are respectively mounted on the top panel 5, the bottom
surface and two side walls of the headentry 3 and configured to monitor the variation
of the cross-sectional shape of the headentry 3. Signals monitored by the top panel
separation indicator, the anchor rod stress analyzer and the shape and position sensors
are all transmitted to the ground through a wire and subjected to data conversion
on the ground; converted data are remotely transmitted by means of Ethernet and the
like; hence workers can remotely monitor and analyze the data, so as to remotely monitor
the state of the headentry 3 in real time.
[0020] After completion of above works, the mining face is gradually extracted until a goaf
is formed. As illustrated in FIG. 4, after the goaf is formed, a side wall on a side
of the headentry 3 of the first mining face 1 is eliminated; the headentry 3 and the
goaf are merged together; and the roadway is eliminated.
[0021] After the goaf is formed on the first mining face 1, a bidirectional energy collecting
pre-splitting blasting device is mounted at the position corresponding to energy collecting
holes 7 on the top panel 5 of the original headentry 3; a blasting lead is connected
for the pre-splitting blasting of the top panel 5 at the position; and a pre-splitting
face is formed on a side of the top panel 5 of the original headentry 3, close to
the goaf. The pre-splitting face is a kerf, bidirectionally extending along the original
headentry 3, on a side of the top panel 5 close to the mining face, namely a directional
kerfing is achieved on the top panel 5 of the original headentry 3. The bidirectional
energy collecting pre-splitting blasting method is recorded in a Chinese patent
ZL200610113007X. The blasting method can not only have the function of pre-splitting the surrounding
rocks of the top panel 5 but also protect the top panel 5 from being damaged by blasting.
Moreover, the blasting method has the advantages of simplicity, ease of use, good
blasting effect, low cost and convenient operation.
[0022] A blasthole is formed on a pre-splitting line by blasting technology; the bidirectional
energy collecting device is adopted for charging; and the energy collecting direction
is driven to correspond to the pre-splitting direction of a rock mass. A cohesive
energy flow is formed by detonation products in two predetermined directions; a concentrated
tensile stress is produced; and the pre-splitting hole is driven to run through the
energy collecting direction to form the pre-splitting face. As rocks between drill
holes are torn down, the explosive consumption is greatly reduced. Meanwhile, as the
energy collecting device protects the surrounding rocks, the damage on the rock mass
on the periphery of the drill hole is also greatly reduced. Therefore, the technology
can not only achieve the objective of pre-splitting but also protect goaf roadway
top panels. The bidirectional energy collecting device is processed by tubular products
(including PVC pipes and metal pipes) with certain strength (the uniaxial compressive
strength is 1.6 MPa to 2.0 MPa); the diameter of the energy collecting device is different
according to the diameter of the hole and determined by the coefficient of the decoupling
charge of specified rock mass; the energy collecting holes on the bidirectional tensile
energy collecting device have various shapes and may be round, elliptical, square,
rectangular and the like; and parameters of the energy collecting holes are determined
by the lithologic characters and explosives. The pore size and the hole pitch of the
energy collecting holes on the bidirectional tensile energy collecting device are
relevant to the lithologic characters, the rock mass structure, the initial stress
state of the engineering rock mass, and the like. Corresponding functional expressions
need to be established. The parameters are designed according to relevant calculation
results.
[0023] As illustrated in FIG. 5, the goaf is caved under the influence of the directional
kerfing and the pressure from a deep stratum above the goaf. As a directional kerfing
is applied to the top panel 5 of the headentry 3 of the original first mining face,
the top panel 5 of the headentry 3 of the original first mining face will not fall
in the case of goaf caving; a slope of the haulage roadway 3 (namely an A area in
FIG. 5) is formed after the caved goaf is caved along the pre-splitting face, on a
pre-splitting side of the headentry 3; and a roadway is formed again at the position
of the original headentry 3. The slope of the newly formed tailentry 3 is sprayed
and sealed by plain concrete so as to prevent harmful gas such as gas and CO in the
goaf from entering into the newly formed tailentry 3. In this way, the headentry 3
of the original mining face is retained and reutilized as a tailentry of the second
mining face. Similarly, in the case of extracting of the third mining face, a headentry
of the second mining face is used as a tailentry of the third mining face by the technique
of the present disclosure.
[0024] Finally, the roadway 3 automatically formed at the position of the headentry of the
original first mining face is taken as a tailentry of the next mining face; a headentry
relative to the tailentry 3 is excavated; and a new mining face is formed. Meanwhile,
the roadways must also be sprayed with urea-formaldehyde polystyrene foam for leakage
resistance and fire resistance.
[0025] The above mining steps are repeated for continuing to mine coal until the coal seam
mining is completed. And hence the longwall working face non-pillared mining process
is achieved.
[0026] In the present disclosure, the energy collecting holes 7 for pre-splitting blasting
are drilled on the working face side of the top panel 5 of the headentry 3; blasting
is performed at the position corresponding to energy collecting holes; a kerf extending
along the original headentry 3 is formed on a side of the top panel 5 close to the
mining face; the goaf is caved along the kerf, so that the roadway can be automatically
formed at the position of the original headentry 3; the top panel 5 of the roadway
3 will not be affected by goaf caving and can be kept in good state; the roadway 3
is taken as a tailentry of the next mining face and the next mining process is continued;
and every two mining faces are continuous and not supported by pillars. Therefore,
compared with the prior art, the longwall working face non-pillared mining method
provided by the present disclosure has prominent substantive features.
Industrial Applicability
[0027] The longwall working face non-pillared mining method provided by the present disclosure
achieves a non-pillared support, has a high mining coefficient, does not require a
long-term wait in the roadway forming process, and hence not only guarantees the safety
but also reduces the time of continuous coal seam mining.
1. A longwall working face non-pillared mining method, comprising steps of:
i) excavating two communicated roadways on a coal seam as a tailentry (2) and a headentry
(3) of a first mining face (1);
ii) reinforcing a top panel (5) of the headentry (3) and drilling on a working face
side of the top panel (5) of the headentry (3) a plurality of energy collecting holes
(7) linearly arranged for pre-splitting blasting;
iii) extracting until a goaf is formed, and the roadway is eliminated;
iv) after the goaf is formed on the first mining face (1), mounting a bidirectional
energy collecting pre-splitting blasting device at a position corresponding to the
energy collecting holes (7) on the top panel (5) of the original headentry (3) of
the goaf, connecting a blasting lead for the pre-splitting blasting of the top panel
5 at the position, and forming a directional kerf, extending up and down along the
entire original headentry (3), on a side of the top panel (5) close to the mining
face (1);
v) making the top panel of the mining face (1) collapse by a pressure from a deep
stratum on an upper portion of the goaf, and forming a new roadway at a position of
the original headentry (3);
vi) taking a roadway, automatically formed at the position of the original headentry
(3), as a tailentry (2) of a next mining face, and excavating a headentry (3) relative
to the tailentry (2), to form a new mining face; and
vii) repeating steps ii) to vi), and continuing to mine coal until the coal seam mining
is completed.
2. The longwall working face non-pillared mining method according to claim 1, characterized in that the step ii) further includes steps of: mounting a sensor on the top panel (5) of
the headentry (3), and wire-transmitting signals to the ground for remotely real-time
monitoring of a status of the headentry (3).
3. The longwall working face non-pillared mining method according to claim 1, characterized in that an anchor rod (6) with constant resistance and large deformation is adopted in the
step ii) to reinforce the top panel (5) of the headentry (3).
4. The longwall working face non-pillared mining method according to claim 1, characterized in that in the steps i) and vi), the roadway is subjected to leakproof and fireproof treatments.
5. The longwall working face non-pillared mining method according to claim 2, characterized in that the sensor in the step ii) includes a top panel (5) separation indicator and an anchor
rod stress analyzer.
1. Strebbauverfahren ohne Pfeiler, das die folgenden Schritte umfasst:
i) Ausschachten von zwei verbundenen Strecken an einem Kohleflöz als eine Fußstrecke
(2) und eine Kopfstrecke (3) einer ersten Abbaufront (1);
ii) Verstärken einer Kopfplatte (5) der Kopfstrecke (3) und Bohren an einer Abbaufront-Seite
der Kopfplatte (5) der Kopfstrecke (3) von mehreren Sprenglöchern (7), die für das
Vorspaltsprengen linear angeordnet sind;
iii) Abbauen, bis sich ein Versatz gebildet hat und die Strecke blockiert ist;
iv) nach dem Ausbilden des Versatzes an der ersten Abbaufront (1) Anbringen einer
bidirektionalen Spreng-Vorspaltsprengvorrichtung an einer Position, die den Sprenglöchern
(7) an der Kopfplatte (5) der ursprünglichen Kopfstrecke (3) des Versatzes entspricht,
Verbinden eines Sprengkabels für das Vorspaltsprengen der Kopfplatte (5) an der Position
und Bilden einer Richtungsfuge, die sich nach oben und unten entlang der gesamten
ursprünglichen Kopfstrecke (3) auf einer Seite der Kopfplatte (5) in der Nähe der
Abbaufront (1) erstreckt;
v) Zusammenbrechenlassen der Kopfplatte (5) der Abbaufront (1) durch einen Druck aus
einer tiefen Schicht auf einem oberen Teil des Versatzes und Bilden einer neuen Strecke
an einer Position der ursprünglichen Kopfstrecke (3);
vi) Nutzen einer Strecke, die automatisch an der Position der ursprünglichen Kopfstrecke
(3) als eine Fußstrecke (2) einer nächsten Abbaufront gebildet wurde, und Ausschachten
einer Kopfstrecke (3) im Verhältnis zur Fußstrecke (2), um eine neue Abbaufront zu
bilden; und
vii) Wiederholen der Schritte ii) bis vi) und Fortsetzen des Kohleabbaus, bis der
Kohleflözabbau abgeschlossen ist.
2. Strebbauverfahren ohne Pfeiler nach Anspruch 1, dadurch gekennzeichnet, dass der Schritt ii) ferner die folgenden Schritte umfasst:
Anbringen eines Sensors an der Kopfplatte (5) der Kopfstrecke (3) und Übertragen von
drahtgebundenen Signalen zum Boden zur Fernüberwachung des Zustands der Kopfstrecke
(3) in Echtzeit.
3. Strebbauverfahren ohne Pfeiler nach Anspruch 1, dadurch gekennzeichnet, dass eine Ankerstange (6) mit konstantem Widerstand und großer Verformung in Schritt ii)
eingesetzt wird, um die Kopfplatte (5) der Kopfstrecke (3) zu verstärken.
4. Strebbauverfahren ohne Pfeiler nach Anspruch 1, dadurch gekennzeichnet, dass die Strecke in den Schritten i) und vi) Verfahren zum Erzielen von Dichtigkeit und
Feuerfestigkeit unterzogen wird.
5. Strebbauverfahren ohne Pfeiler nach Anspruch 2, dadurch gekennzeichnet, dass der Sensor in Schritt ii) eine Trennungsanzeigeeinrichtung für die Kopfplatte (5)
und einen Ankerstangenspannungsanalysator aufweist.
1. Procédé d'exploitation minière sans pilier à front de taille par longue taille, comprenant
les étapes suivantes :
i) excavation de deux galeries communicantes sur une veine de charbon en tant qu'entrée
d'extraction (2) et entrée d'évacuation (3) d'un premier front d'exploitation (1)
;
ii) renforcement d'un panneau supérieur (5) de l'entrée d'extraction (3) et forage,
sur un front de taille du panneau supérieur (5) de l'entrée d'extraction (3), d'une
pluralité de trous d'accumulation d'énergie (7) disposés de manière linéaire pour
un prédécoupage ;
iii) extraction jusqu'à formation d'un remblai et élimination de la galerie ;
iv) après formation du remblai sur le premier front d'exploitation (1), montage d'un
dispositif de prédécoupage avant abattage récupérant une énergie bidirectionnelle
à une position correspondant aux trous de récupération d'énergie (7) sur le panneau
supérieur (5) de l'entrée d'extraction d'origine (3) du remblai, raccordement d'une
tête d'abattage pour le prédécoupage avant abattage du panneau supérieur (5) au niveau
de la position et formant une entaille directionnelle s'étendant de haut en bas sur
toute la hauteur de l'entrée d'exploitation d'origine (3), d'un côté du panneau supérieur
(5) près du front d'exploitation (1) ;
v) éboulement du panneau supérieur du front d'exploitation (1) sous l'effet d'une
pression exercée par une strate profonde sur une partie supérieure du remblai, et
formation d'une nouvelle galerie à un emplacement de l'entrée d'extraction d'origine
(3) ;
vi) détermination d'une galerie, formée automatiquement à la position de la hauteur
d'entrée d'extraction d'origine (3), en tant qu'entrée d'évacuation (2) d'un front
d'exploitation suivant, et excavation d'une entrée d'extraction (3) par rapport à
l'entrée d'évacuation (2), pour former un nouveau front d'exploitation ; et
vii) répétition des étapes ii) à vi), et en continuant à exploiter le charbon jusqu'à
ce que l'extraction de la veine de charbon soit terminée.
2. Procédé d'exploitation minière sans pilier à front de taille par longue taille, selon
la revendication 1, caractérisé en ce que l'étape ii) comprend en outre les étapes consistant à :
monter un capteur sur le panneau supérieur (5) de l'entrée d'extraction (3) et émettre
des signaux par fil au sol pour une surveillance à distance en temps réel de l'état
de l'entrée d'extraction (3).
3. Procédé d'exploitation minière sans pilier à front de taille par longue taille, selon
la revendication 1, caractérisé en ce qu'une tige d'ancrage (6) à résistance constante et à forte déformation pour renforcer
le panneau supérieur (5) de l'entrée de tête (3) est adoptée dans l'étape ii).
4. Procédé d'exploitation minière sans pilier à front de taille par longue taille, selon
la revendication 1, caractérisé en ce que dans les étapes i) et vi), la galerie est soumise à des traitements antifuites et
antifeu.
5. Procédé d'exploitation minière sans pilier à front de taille par longue taille, selon
la revendication 2, caractérisé en ce que le capteur dans l'étape ii) comprend un indicateur de séparation du panneau supérieur
(5) et un analyseur de contrainte de tige d'ancrage.