CN111535817A - Working face double-lane tunneling small coal pillar reinforcement construction method - Google Patents
Working face double-lane tunneling small coal pillar reinforcement construction method Download PDFInfo
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- CN111535817A CN111535817A CN202010271511.2A CN202010271511A CN111535817A CN 111535817 A CN111535817 A CN 111535817A CN 202010271511 A CN202010271511 A CN 202010271511A CN 111535817 A CN111535817 A CN 111535817A
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- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D9/00—Tunnels or galleries, with or without linings; Methods or apparatus for making thereof; Layout of tunnels or galleries
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- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D11/00—Lining tunnels, galleries or other underground cavities, e.g. large underground chambers; Linings therefor; Making such linings in situ, e.g. by assembling
- E21D11/04—Lining with building materials
- E21D11/10—Lining with building materials with concrete cast in situ; Shuttering also lost shutterings, e.g. made of blocks, of metal plates or other equipment adapted therefor
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- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D15/00—Props; Chocks, e.g. made of flexible containers filled with backfilling material
- E21D15/02—Non-telescopic props
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- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D20/00—Setting anchoring-bolts
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- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D20/00—Setting anchoring-bolts
- E21D20/02—Setting anchoring-bolts with provisions for grouting
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- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D9/00—Tunnels or galleries, with or without linings; Methods or apparatus for making thereof; Layout of tunnels or galleries
- E21D9/006—Tunnels or galleries, with or without linings; Methods or apparatus for making thereof; Layout of tunnels or galleries by making use of blasting methods
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- 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
- E21F17/103—Dams, e.g. for ventilation
Abstract
The invention provides a working face double-roadway tunneling small coal pillar reinforcement construction method, and relates to the technical field of coal mining and roadway support. The method comprises the following steps: arranging double-roadway tunneling on a working face, and reserving small coal pillars of 3-5m between the roadways; installing a through anchor cable on the small coal pillar to enable the coal pillar to be in a three-dimensional stress state; grouting anchor rods are arranged on two sides of the small coal pillar to control surrounding rock cracks, so that the integrity of the coal pillar is guaranteed; mounting a suspension anchor cable to strengthen the connection between the coal pillar and the overlying rock stratum and prevent the coal pillar from sliding; the coal side is provided with a steel pipe concrete pier column for reinforcement, so that the bearing capacity of the coal column is improved, and the side drum is controlled; and during the recovery period, advanced pre-top breaking pressure relief is carried out, and the supporting pressure above the coal pillar is reduced. The method ensures the stability of the small coal pillars in the tunneling and stoping processes, the problem of tension on the mine working face can be relieved by double-lane tunneling, and the mining rate can be improved by the arrangement of the small coal pillars; in addition, the bearing capacity of the small coal pillar is improved, the long-term stability of the small coal pillar is ensured, and the double-lane tunneling of the small coal pillar is realized.
Description
Technical Field
The invention relates to the technical field of coal mining and roadway support, in particular to a working face double-roadway tunneling small coal pillar reinforcement construction method.
Background
The traditional double-lane tunneling can realize the sequential stoping of a working face and ensure the normal mining and replacement; however, on the basis of mine pressure control, 10-30 m of protective coal pillars are generally reserved, which causes a great waste of coal resources. Although the width of a coal pillar is reduced, the resource extraction rate is improved, the roadway is close to a goaf and is easily subjected to large deformation caused by the influence of movement of a rock stratum above the goaf, so that the roadway is generally kept in a lag period of 6-10 months, and the problem of insufficient mining and replacement is brought. The current support control technology aiming at the small coal pillar mainly comprises the traditional anchor rod cable and metal net support, and the key parts are reinforced support, grouting, guniting and the like. Under the supporting system, supporting structures on two sides of the coal pillar are not connected, and bidirectional reinforcement cannot be guaranteed; meanwhile, the integrity of the coal pillar is damaged by excessive anchor rod cable holes on two sides, the small coal pillar is easy to generate plastic damage on the whole width, the bulging phenomenon is serious, the roadway can generate large deformation, and serious problems such as air leakage and fire disaster of a goaf can be caused. The combination of the existing support modes such as anchor rod, anchor cable and grouting is difficult to realize the long-term control of the small coal pillar, and the contradiction between the working face continuation and the coal extraction rate cannot be solved, so that the existing construction method needs to be further improved.
Disclosure of Invention
The invention provides a working face double-lane tunneling small coal pillar reinforcement construction method, which aims to solve the problem that stability control of small coal pillars reserved in double-lane tunneling is difficult due to the influence of mining, guarantee working face mining replacement, improve the coal mining rate and improve the bearing capacity of the small coal pillars.
A working face double-lane tunneling small coal pillar reinforcement construction method comprises the following steps:
step 1, performing double-lane tunneling on one side of a coal face, and reserving a small coal pillar of 3-5m between an advance lane and a delay lane;
step 2, supporting the roadway after the advance roadway and the lag roadway are tunneled, and driving a grouting anchor rod to the side of the small coal pillar in the roadway;
step 3, installing a suspension anchor cable, wherein the suspension anchor cable penetrates through the small coal pillar and is obliquely fixed in the overlying rock stratum;
step 4, installing opposite-penetrating anchor cables on the small coal pillars along with the lagging roadway driving working face, and applying lateral confining pressure to the two sides of the small coal pillars through the opposite-penetrating anchor cables;
step 5, arranging concrete-filled steel tube pier columns at the two sides of the small coal pillars 8-12m behind the driving working face of the lagging roadway, wherein the concrete-filled steel tube pier columns support the small coal pillars in an inclined manner towards one sides of the small coal pillars;
6, grouting two sides of the small coal pillar by using a grouting anchor rod 40-50m behind the driving working surface of the lagging roadway;
step 7, repeating the steps 1 to 6 until double-lane tunneling is completed;
and 8, after the coal face begins to recover, constructing the top breaking pressure relief in the advanced face of the coal pillar side in the roadway.
Preferably, when the roadway is supported after the advance roadway and the delay roadway are tunneled, a grouting anchor rod is arranged, and a suspension anchor cable is installed.
Preferably, one connecting roadway is arranged between the roadways every 50-100m, and the tunneling working face of one roadway lags behind the tunneling working face of the other roadway by 3-5m during double-roadway tunneling.
Preferably, the length of the grouting anchor rod is less than half of the width of the small coal pillar, the anchoring end of the suspension anchor cable is arranged in the upper hard rock stratum, and the vertical inclination angle of the suspension anchor cable is less than 30 degrees.
Preferably, when the anchor cable is installed, construction is simultaneously carried out on two sides of the coal pillar; and (3) pre-tightening the penetrating anchor cable by adopting a multi-cycle pre-tightening mode, and tensioning the penetrating anchor cable by adopting graded tensioning.
It is further preferred that the total length of the opposite-penetrating anchor rope is larger than the width of the small coal pillar, the opposite-penetrating anchor rope comprises a free section and an exposed section, and the length of the exposed section is 200mm and 300 mm.
Further preferably, the steel pipe concrete pier column is inclined to one side of the small coal column by 3-5 degrees, and a gap of 300-500mm is formed between the steel pipe concrete pier column and the small coal column.
Preferably, when the steel pipe concrete pier stud is constructed, 6-8 hollow steel pipes are erected firstly, and then concrete is injected into the hollow steel pipes; and a steel tray is arranged at the top of the steel pipe concrete pier, and a flexible cushion layer is arranged between the steel tray and the hollow steel pipe.
Preferably, the coal face is stoped, top breaking drilling is started from opening the cutting hole in advance of the face construction, and the hole is sealed after explosive is placed in the drilling hole, and presplitting blasting is carried out; and a sealing wall is arranged along with the propulsion of the working face to seal the connection roadway.
The working face double-lane tunneling small coal pillar reinforcing construction method provided by the invention has the beneficial effects that:
(1) the method adopts a double-lane tunneling mode, so that sequential stoping of a working face is ensured, and meanwhile, a stoping tunnel is pre-dug for the next working face, so that mining succession is ensured; the small coal pillars are comprehensively supported by using the opposite-penetrating anchor cables, the grouting anchor rods, the suspension anchor cables and the steel pipe concrete pier pillars, so that the stability of the coal pillars is ensured; during stoping, pressure relief is carried out by utilizing advanced top breaking, so that long-term stability of the roadway is ensured.
(2) The width of the small coal pillar reserved between the two roadways is far smaller than that of the protective coal pillar reserved in the traditional double-roadway tunneling, so that the extraction rate is greatly improved, the fire disaster caused by excessive coal pillars in the goaf is avoided, and the danger of rock burst can be effectively avoided.
(3) The method uses the opposite-penetrating anchor cable on the coal pillar between two roadways, so that the construction of the opposite-penetrating anchor cable is more convenient, the opposite-penetrating anchor cable changes the stress state of the small coal pillar, the small coal pillar is stressed in three directions, and the self bearing capacity of the coal pillar is improved; the grouting anchor rod can effectively control the surrounding rock cracks and enhance the integrity and stability of the small coal pillar; the suspension anchor cable strengthens the mechanical relation between the coal pillar and the overlying rock stratum and prevents the small coal pillar from slipping; the small coal pillars are reinforced from the side faces of the steel pipe concrete pier pillars and provide support for overlying rocks in cooperation with the small coal pillars, so that the bearing capacity of the coal pillars is further improved; and in the recovery process, the pressure of the overlying strata is relieved through advanced pre-breaking of the roof, so that the stability of the small coal pillar during the recovery period of the working face is ensured. The combination of the penetrating anchor cable, the grouting anchor rod, the suspending anchor cable and the steel pipe concrete pier column acts on the reinforcement of the small coal pillar, and acts on each stage of roadway excavation in a synergistic manner, the stability of the roadway is guaranteed through advanced top breaking pressure relief during the stoping period, and the long-term stable control over the small coal pillar is realized.
Drawings
Fig. 1 is a schematic plan view of a double-lane excavation;
FIG. 2 is a construction schematic diagram of a double-lane tunneling small coal pillar;
FIG. 3 is a schematic cross-sectional structure of a small coal pillar;
FIG. 4 is a diagram of a leading top-break pressure relief drilling construction layout;
in the figure: 1-advanced roadway; 2-a lagging roadway; 3-small coal pillar; 4-connecting lane; 5, oppositely penetrating anchor cables; 6-grouting anchor rod; 7, suspending the anchor cable; 8-steel pipe concrete pier stud; 9-a flexible cushion layer; 10-a steel tray; 11-section haulage roadway; 12-a track lane of the lower section; 13-a pilot hole; 14-blast hole; 15-working surface.
Detailed Description
A specific embodiment of the working face double-roadway tunneling small coal pillar reinforcement construction method provided by the present invention will be described with reference to fig. 1 to 4.
Example 1
A working face double-lane tunneling small coal pillar reinforcement construction method, a double-lane tunneling small coal pillar reinforcement technology and a construction process are provided, and double-lane arrangement can solve the problem of insufficient mining and taking over. The small coal pillar is reserved for protecting the roadway, so that the coal extraction rate is improved, and the resource loss is reduced; meanwhile, the composite reinforcing support taking the bidirectional opposite-penetrating anchor cable as a main body can greatly improve the bearing capacity of the small coal pillar, solve the problem that the small coal pillar is difficult to maintain long-term stability due to the influence of extraction, and ensure the feasibility of a double-roadway tunneling technology for reserving the small coal pillar. The method comprises the following steps:
firstly, according to geological and mine mining technical conditions, comprehensive means such as theoretical calculation, simulation and the like are utilized to carry out scheme design in the early stage, and the determination of reasonable relevant excavation parameters comprises the following steps: leaving parameters such as the width of the small coal pillar, the distance between the connecting roadways, the distance between the two tunneling surfaces and the like; and parameters such as arrangement modes, hole depths, inter-row distances, angles and the like of the through anchor cables, the grouting anchor rods and the suspension anchor cables; and parameters such as material selection, spacing, core concrete strength, arrangement spacing and the like of the steel pipe concrete pier stud; the top cutting height of the pre-broken top of the advanced blasting, the inclination angle of the drill hole, the aperture of the drill hole, the arrangement interval of the drill hole, the interval between the guide hole and the explosive loading hole, the explosive loading amount, the sealing length, the blasting mode and other parameters.
Step 1, performing double-lane tunneling on one side of a coal face, and reserving a small coal pillar of 3-5m between an advance lane and a delay lane.
Wherein, one connecting roadway is arranged between the roadways every 50-100m and is used for communicating the two roadways in the construction process. When the double-lane tunneling is carried out, the tunneling working face of one lane lags behind the tunneling working face of the other lane by 3-5m, and the two lanes are a leading lane and a lagging lane respectively.
And 2, immediately supporting the roadway after the advancing roadway and the lagging roadway are tunneled, and drilling a grouting anchor rod to the side of the small coal pillar in the roadway. Wherein the length of slip casting stock is less than half of little coal column width, avoids the destruction of overlength drilling hole to the coal column wholeness.
The specification of the grouting anchor rod can be selected from 20mm phi, 22mm phi, 25mm phi and 32mm phi, the length of the anchor rod is selected according to the width of a coal pillar smaller than 1/2, the interval row pitch is designed according to the interval row pitch of the through anchor cables and is in cross arrangement with the through anchor cables, and 0.5-1 grouting anchor rod is preferably arranged per square meter. When the grouting anchor rod is constructed, firstly, drilling holes on the roadway side of the roadway, installing the grouting anchor rod according to design parameters, and checking the exhaust holes of the anchor rod body for later use.
The grouting anchor rod injects cementing materials into the coal body cracks through a connecting grouting machine, the grouting anchor rod is used as a common anchor rod before grouting, and the rod body and surrounding rock of the coal pillar body are anchored to form a stable bearing structure; and after grouting, cementing slurry materials are injected into the coal pillar cracks through the rod body, and the broken coal pillars are bonded into a unified whole, so that the bearing capacity of the coal pillars is improved. Compared with the traditional anchor rod construction process, the pressure grouting is formed, not only can the anchor hole be filled, but also the slurry can fill the crack under the action of pressure to bond the coal body. Meanwhile, the slurry loss when the grouting pipe is pulled out is avoided, the installation is convenient, and the supporting effect is good.
And 3, installing a suspension anchor cable, wherein the suspension anchor cable penetrates through the small coal pillar and is obliquely fixed in the overburden stratum.
When the suspension anchor cable is constructed, the anchoring end of the suspension anchor cable is arranged in the hard overlying rock stratum, the vertical inclination angle of the suspension anchor cable is smaller than 30 degrees, and the top of the small coal pillar is directly suspended in the hard overlying rock stratum. And the suspension anchor rope controls the coal pillar to slide, wherein the suspension anchor rope should be arranged obliquely upwards from the tops of two sides of the coal pillar, the distance between the opening point and the top of the coal pillar is about 300-500mm, and the length of the anchor rope is designed according to the structure and the thickness of the top plate of the overlying strata, so that the top of the anchor rope is anchored in a stable rock stratum by about 1-2 m. In the axial direction of the roadway, the arrangement distance of the suspension anchor cables is about 1500-2500 mm.
Suspending anchor cables are constructed to the top plate in roadways on two sides of the small coal pillar in a suspension mode, the anchor cables on the two sides penetrate through the top end of the small coal pillar to be constructed obliquely upwards, and the top of the coal pillar is directly suspended in the hard overlying rock stratum, so that discontinuous surfaces of coal rock bodies are extruded and compacted to form an integrated body of interaction, the shearing resistance between the discontinuous surfaces is enhanced, and the phenomena of coal slope deformation, small coal pillar external error, slippage and the like in the roadways are avoided.
In addition, grouting anchor rods are arranged when the roadway is supported after the advance roadway and the delay roadway are tunneled, and suspension anchor cables are installed, so that the safety of tunneling is guaranteed.
And 4, installing a through anchor cable in the small coal pillar by taking the lagging roadway tunneling working surface as a standard, and applying lateral confining pressure to two sides of the small coal pillar through the through anchor cable.
Wherein the total length of the opposite-penetrating anchor cable is larger than the width of the small coal pillar, the opposite-penetrating anchor cable comprises a free section and an exposed section, and the length of the exposed section is 200-300 mm. When the anchor cable is in construction, the anchor cable is delayed from a roadway tunneling head, the small coal pillar is reinforced in two directions, the anchor cable is pre-tightened and tensioned at two ends through drilling and cable penetrating, and finally hole sealing and grouting are carried out to protect the exposed end. When the anchor cable is penetrated, simultaneous construction is carried out on two sides of the coal pillar, and people need to be arranged in roadways on two sides respectively to carry out simultaneous operation, so that the anchoring pretightening force on the two sides is ensured to be the same. And (3) pre-tightening the penetrating anchor cable by adopting a multi-cycle pre-tightening mode, and tensioning the penetrating anchor cable by adopting graded tensioning.
The anchor cable is drilled into small coal pillars in roadways on two sides, a common anchor cable bundle body is penetrated, and the anchor cable bundle body is tensioned and pre-tightened through trays and locks at two ends by adopting a tensioning device, so that the small coal pillars are reinforced and supported bidirectionally. The existing anchor cable is difficult to construct on two sides simultaneously when in use, so that the confining pressure application effect is poor. And simultaneously, slurry filling is carried out in the anchor cable holes, so that the bundle body is effectively bonded with the coal pillar. To wearing the high compressive capacity of the tensile ability of anchor rope make full use of the bundle body and coal body structure, the anchor rope is consolidated the back to little coal column, and two free surfaces of coal column in the both sides tunnel all receive the compression, provide higher side direction confined pressure for little coal column, change one-way stress state into three-dimensional stress state, improve the mechanics bearing performance of little coal column greatly.
In the bi-directional reinforcement construction of the opposite-penetrating anchor cable, the opposite-penetrating anchor cable is formed by modifying a common anchor cable commonly used in a coal mine and consists of a free section and a locking section. The free section is a bundle body woven by steel strands, and the full width of the bundle body penetrates through a coal pillar during construction; the locking section is located the coal pillar both sides tunnel, comprises tray and tool to lock, can both ends locking, exerts the pretightning force. The specification of the anchor cable can be selected from phi 17.8mm and phi 21.6mm, the spacing parameter can be designed to be 1000-. When the anchor cable is penetrated, two sides of the anchor cable need to operate simultaneously so as to ensure that anchoring pretightening force is the same. And (4) performing anchoring pre-tightening by adopting multiple cycles and tensioning in stages. And grouting and sealing the full-length section in the anchor cable hole.
And 5, arranging concrete-filled steel tube pillars on the two sides of the small coal pillar at 8-12m of the driving working surface of the lagging roadway, and supporting the small coal pillar by inclining the concrete-filled steel tube pillars to one side of the small coal pillar.
The small coal pillar is reinforced in an auxiliary mode in the lateral direction of the steel pipe concrete pier column, the steel pipe concrete pier column is made of seamless steel pipes and inner core concrete, the steel pipes can be made of Q235, Q245, Q345, Q390 and the like, the outer diameter of each steel pipe is 108mm-325mm, the wall thickness of each steel pipe is 6mm-16mm, the distance is 600-800mm, and the strength of the core concrete is not lower than C40 level. The bearing capacity of the determined model of the concrete filled steel tube pier column is higher than the support resistance calculated theoretically, and about 30% of margin coefficient is reserved. During construction, the pillars on both sides are deviated to the coal pillar side by an angle of 3-5 degrees, and a distance of 300-500mm is reserved between the pillars and the coal pillar. The height of the pier column is about 200-300mm lower than that of the coal column, and the flexible cushion layer is used as a buffer to press the layer and can be processed and manufactured by materials such as wood wedges, cement back plates and the like, so that the tight roof contact is ensured. In order to effectively prevent the pier stud from drilling the top, the top of the pier stud penetrates into the top plate rock stratum along with the sinking of the top plate, and the top end of the pier stud is also provided with a steel tray of 500mm multiplied by 500 mm.
The concrete-filled steel tube pier column is inclined by 3-5 degrees to one side of the small coal column so as to laterally protect the coal column, and a gap of 300-500mm is reserved between the concrete-filled steel tube pier column and the small coal column, so that the deformation can be effectively adapted. When the steel pipe concrete pier stud is constructed, 6-8 hollow steel pipes are erected firstly, and then concrete is injected into the hollow steel pipes; wherein hollow steel pipe top installation steel tray has guaranteed the stability of steel pipe concrete pier stud, and the top sets up the flexible bed course, guarantees to connect the top closely knit. When the concrete-filled steel tube pier column is erected, simultaneous operation is required in roadways on two sides.
The lateral auxiliary reinforcement of the concrete-filled steel tube pier columns is characterized in that a row of concrete-filled steel tube pier columns are erected on two sides of a small coal pillar respectively, and the concrete-filled steel tube pier columns are formed by filling core concrete into external seamless steel tubes and have very high bearing capacity and structural stability. On one hand, the steel pipe concrete pier column can bear the overlying strata pressure together with the coal pillar; on the other hand, an extra transverse resistance is applied to the small coal pillars, so that the lateral confining pressure of the small coal pillars is further enhanced, the bearing capacity of the coal pillars is improved, and the small coal pillars can be prevented from bulging towards the roadway.
And 6, grouting two sides of the small coal pillar by using a grouting anchor rod 40-50m behind the driving working surface of the lagging roadway, wherein the lagging distance is determined according to the crack development degree of the coal pillar.
The grouting reinforcement material of the anchor rod can be selected from cementing materials such as Guoante, Marilyn and the like, and selective grouting is carried out according to the development degree of cracks in the coal pillar.
And 7, repeating the steps 1 to 6 until the double-lane tunneling is completed.
And 8, after the coal face begins to recover, constructing the top breaking pressure relief in the advanced face of the coal pillar side in the roadway. And a sealing wall is arranged along with the propulsion of the working face to seal the connection roadway.
And (3) stoping the coal face, carrying out top breaking drilling on the coal face from the open cut hole, placing explosives in the drilling holes, sealing the holes, and carrying out presplitting blasting. After the working face is pushed and mined, the roof collapses along the cutting seam of the presplitting blasting under the action of mine pressure, so that the pressure relief is realized, and the rock burst is effectively avoided.
Drilling and blasting are carried out on the side, close to the coal pillar, of the roadway in advance of the working face for a certain distance, presplitting cutting seams are formed through presplitting blasting, and after the working face is pushed, a top plate above the coal pillar is broken and falls along the edges of the coal pillar under the action of self gravity and mine pressure. The pre-splitting blasting reduces the suspended ceiling area of the top plate above the coal pillar, reduces the stress concentration of the small coal pillar, improves the supporting condition of the roadway, completes the pressure relief of the working face, and effectively prevents and controls the rock burst disaster.
Example 2
In this embodiment, a working face double-roadway tunneling small coal pillar reinforcement construction method is described in detail by taking a preparation roadway of a working face of a certain mine 1205 as an example. The working face is designed into a tunnel with a rectangular section, the width of the tunnel is 5.0m, the height of the tunnel is 3.2m, the coal bed of the tunneling working face is directly propped up by siltstone, the thickness of the tunnel is 3m, the basic top is shale, the thickness of the tunnel is 5m, and the mining height of the coal bed is 2 m.
Firstly, according to geological and mine mining technical conditions, determining reasonable related technical parameters through theoretical calculation and simulation: small coal pillars with the width of 5m are reserved, the distance between connecting roadways is 50m, the distance difference between two tunneling surfaces is 5m, the diameter of each anchor cable is 17.8mm multiplied by 5400mm, the row distance between the anchor cables is 1000mm multiplied by 1000mm, and the anchor cables are arranged in a square mode. The grouting anchor rods are selected to be phi 25mm multiplied by 2000mm, the row spacing between the anchor rods is 1000mm multiplied by 1000mm, the grouting anchor rods are arranged in a square mode, and the cementing reinforcing material is selected to be Guander. The suspension anchor cable is selected to be phi 17.8mm multiplied by 5200mm, the interval is 2000mm, and the included angle between the anchor cable penetrating the upper part of the coal pillar and the vertical direction is 30 degrees. 325mm, wall thickness 8mm are got to the steel pipe external diameter in the steel pipe concrete pier stud, arrange that the interval is 600mm, pier stud and little coal column interval 300mm, to coal column side skew angle be 3, and the core concrete intensity is C40 level, and top flexible cushion thickness is 200 mm. The presplitting blasting technology with the guide hole is selected for the advanced presplitting top, the drilling depth is 3m, the drilling inclination angle is 10 degrees, the drilling hole diameter is 42mm, the distance between the charging holes is 1200mm, the distance between the guide hole and the charging hole is 600mm, and the hole sealing length is 600 mm.
The concrete construction comprises the following steps:
step 1: and (3) starting the tunnel construction, adopting double-tunnel tunneling, wherein the difference between the advance tunnel and the delay tunnel is 5m, 5 m-wide small coal pillars are reserved between the two tunnels, and one connecting tunnel is arranged every 50m and is used for communication between the two tunnels in the construction process.
Step 2: when the advanced roadway is tunneled forwards, a grouting anchor rod and a suspension anchor cable are constructed in time afterwards. And (3) drilling holes on the roadway sides at the two sides of the coal pillar according to design parameters, after the drilled holes are cleaned, inserting the grouting anchor rods with the installed anchor heads into the drilled holes, installing grout stop plugs, backing plates and nuts, and inspecting the rod bodies and exhaust holes after the installation for later grouting. Suspending anchor cable construction, punching holes obliquely upwards at the top ends in roadways on two sides of the coal pillar according to design parameters, enabling the hole-punching points to be 300mm away from the top of the coal pillar, after the holes are cleaned, sending resin cartridges and the anchor cables into the holes for stirring, installing a tray and a lockset, and performing tensioning and pre-tightening.
And step 3: and when the lagging roadway is tunneled forwards, constructing a grouting anchor rod, a suspension anchor cable and a bidirectional reinforcing anchor cable in time afterwards. And the construction of the grouting anchor rod and the suspension anchor cable is the same as the step 2. The anchor cable is reinforced in two-way mode, and the lagged roadway is used as a standard, personnel are required to be arranged in the roadways on two sides respectively for simultaneous operation, holes are drilled according to design parameters during construction, after the holes are cleaned up, whether the formed holes meet requirements is checked, then the anchor cable penetrates into the holes, the cable body is kept smooth, a tensioning device is adopted, and the anchor cable is locked, tensioned and pre-tensioned through the trays and the lockset at two ends. And the pre-tightening adopts a multi-cycle pre-tightening mode, the tensioning adopts graded tensioning, and the hole sealing and grouting are carried out after the tensioning for external protection.
And 4, step 4: and (3) driving a 10m late roadway to construct the concrete-filled steel tube pier column, and simultaneously operating in the roadways on two sides when the pier column is erected. The method comprises the following steps of conveying the ground processed hollow steel pipe to an underground roadway, erecting the hollow steel pipe according to design requirements, installing a flexible cushion layer between the steel pipe and a top plate, ensuring that the roof is tightly connected, and installing a 500mm multiplied by 500 steel tray on the upper portion of the flexible cushion layer. And after erection, injecting the prepared core concrete into the hollow steel pipes, performing concentrated concrete grouting once for each erection of 6 to 8 hollow steel pipes, and fully injecting and compacting each steel pipe to form the complete steel pipe concrete pier column.
And 5: and (5) performing anchor rod grouting construction by lagging roadway excavation for 50 m. And connecting the grouting machine with the tail end of the grouting anchor rod, injecting a cementing reinforcing material into the rod body, and stopping curing after the grouting is full.
Step 6: and repeating the construction steps 1 to 5 until the tunneling of the roadway is completed.
And 7: after the working face is mined, a leading top-breaking drill hole is constructed in the roadway close to the coal pillar side and in front of the working face for a certain distance, and the distance between the drill hole and the coal pillar side is 200 mm. And (4) drilling, charging and blasting according to design parameters to form a presplitting kerf on the side of the small coal pillar. After the working face is pushed, the top plate above the coal pillar is broken and collapsed along the edge of the coal pillar under the action of self weight and mine pressure, and pressure relief of the working face is completed. Meanwhile, with the advance of the working face, the connecting roadway between the two roadways is sealed by a sealing wall.
The method establishes an all-dimensional and full-stage small coal pillar composite reinforcement technical system, the two-way opposite-penetrating anchor cable is used as a main body to reinforce the coal pillar, and the unidirectional stress state of the coal pillar is changed into a three-way stress state, so that the self bearing capacity of the coal pillar is greatly improved; the surrounding rock cracks are controlled by grouting with the anchor rods, and the integrity and stability of the coal pillars are enhanced; the suspension anchor cable is used for enhancing the mechanical connection between the coal pillar and the overlying strata, and preventing the coal pillar from sliding in a wrong way; the concrete-filled steel tube pier column is used for laterally reinforcing the coal side and supporting the overlying strata together with the coal column, so that the bearing capacity of the coal column is further improved; the advanced pre-breaking roof is used for carrying out staged pressure relief, and good conditions are provided for maintenance of small coal pillars and roadways during stoping of a working face.
It is to be understood that the above description is not intended to limit the present invention, and the present invention is not limited to the above examples, and those skilled in the art may make modifications, alterations, additions or substitutions within the spirit and scope of the present invention.
Claims (9)
1. A working face double-lane tunneling small coal pillar reinforcement construction method is characterized by comprising the following steps:
step 1, performing double-lane tunneling on one side of a coal face, and reserving a small coal pillar of 3-5m between an advance lane and a delay lane;
step 2, supporting the roadway after the advance roadway and the lag roadway are tunneled, and driving a grouting anchor rod to the side of the small coal pillar in the roadway;
step 3, installing a suspension anchor cable, wherein the suspension anchor cable penetrates through the small coal pillar and is obliquely fixed in the overlying rock stratum;
step 4, installing opposite-penetrating anchor cables on the small coal pillars along with the lagging roadway driving working face, and applying lateral confining pressure to the two sides of the small coal pillars through the opposite-penetrating anchor cables;
step 5, arranging concrete-filled steel tube pier columns at the two sides of the small coal pillars 8-12m behind the driving working face of the lagging roadway, wherein the concrete-filled steel tube pier columns support the small coal pillars in an inclined manner towards one sides of the small coal pillars;
6, grouting two sides of the small coal pillar by using a grouting anchor rod 40-50m behind the driving working surface of the lagging roadway;
step 7, repeating the steps 1 to 6 until double-lane tunneling is completed;
and 8, after the coal face begins to recover, constructing the top breaking pressure relief in the advanced face of the coal pillar side in the roadway.
2. The working face double-roadway driving small coal pillar reinforcement construction method according to claim 1, wherein grouting anchor rods are arranged during roadway supporting after driving of the advancing roadway and the lagging roadway, and suspension anchor cables are installed at the same time.
3. The working face double-lane tunneling small coal pillar reinforcement construction method according to claim 1, wherein a connecting lane is arranged between every 50-100m of the tunnels, and the tunneling working face of one tunnel lags behind the tunneling working face of the other tunnel by 3-5m during double-lane tunneling.
4. The working face double-lane tunneling small coal pillar reinforcement construction method according to claim 1, wherein the length of the grouting anchor rod is less than half of the width of the small coal pillar, the anchoring end of the suspension anchor cable is arranged in the overlying hard rock stratum, and the vertical inclination angle of the suspension anchor cable is less than 30 degrees.
5. The working face double-lane tunneling small coal pillar reinforcement construction method according to claim 1, wherein during installation of the opposite anchor cables, construction is simultaneously performed on two sides of the coal pillar; and (3) pre-tightening the penetrating anchor cable by adopting a multi-cycle pre-tightening mode, and tensioning the penetrating anchor cable by adopting graded tensioning.
6. The working face double-lane tunneling small coal pillar reinforcement construction method as claimed in claim 5, wherein the total length of the through anchor cable is greater than the width of the small coal pillar, the through anchor cable comprises a free section and an exposed section, and the length of the exposed section is 200-300 mm.
7. The working face double-lane tunneling small coal pillar reinforcement construction method according to claim 1, wherein the concrete-filled steel tube pier column is inclined 3-5 degrees to one side of the small coal pillar, and a gap of 300-500mm is formed between the concrete-filled steel tube pier column and the small coal pillar.
8. The working face double-lane tunneling small coal pillar reinforcement construction method according to claim 7, wherein during construction of the steel tube concrete pier, 6-8 hollow steel tubes are erected, and then concrete is injected into the hollow steel tubes; and a steel tray is arranged at the top of the steel pipe concrete pier, and a flexible cushion layer is arranged between the steel tray and the hollow steel pipe.
9. The working face double-roadway driving small coal pillar reinforcement construction method according to claim 1, wherein the coal face begins to recover, top breaking drilling is conducted in advance of working face construction from a cut hole, holes are sealed after explosives are placed in the drilling holes, and pre-splitting blasting is conducted; and a sealing wall is arranged along with the propulsion of the working face to seal the connection roadway.
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112727460A (en) * | 2020-12-29 | 2021-04-30 | 山西石泉煤业有限责任公司 | Advanced pressure relief and corner fixing method for adjacent stope of high-gas mine |
| CN112983419A (en) * | 2021-03-18 | 2021-06-18 | 神华神东煤炭集团有限责任公司 | Working face coal pillar setting method |
| CN113137243A (en) * | 2021-03-27 | 2021-07-20 | 山东新巨龙能源有限责任公司 | Reinforcing method for corrosion-resistant interchange roadway of loose coal cylinder |
| CN113279795A (en) * | 2021-06-29 | 2021-08-20 | 辽宁工程技术大学 | Drilling, anchoring, digging and repairing rapid tunneling construction process method |
| CN114198104A (en) * | 2021-12-15 | 2022-03-18 | 中天合创能源有限责任公司 | Long-distance coal pillar plugging and reinforcing method |
| CN115839249A (en) * | 2023-01-16 | 2023-03-24 | 煤炭科学技术研究院有限公司 | Method for arranging ultra-long working face double-measure roadway under sequential mining condition |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SU1033758A1 (en) * | 1982-04-23 | 1983-08-07 | Шахта "Юбилейная" Производственного Объединения "Гидроуголь" | Method of protecting seam-type mine workings |
| WO2008087538A2 (en) * | 2007-01-18 | 2008-07-24 | Skarboevig Nils Mittet | A versatile grout bag type of underground support |
| CN102425439A (en) * | 2012-01-17 | 2012-04-25 | 中国矿业大学 | Method for reinforcing bidirectional staged stretched anchor cable of preset steel strand |
| CN107060758A (en) * | 2017-04-18 | 2017-08-18 | 辽宁工程技术大学 | A kind of section fender, which is stayed, sets construction method |
| CN108590723A (en) * | 2018-05-24 | 2018-09-28 | 中煤能源研究院有限责任公司 | Gob side entry driving fender erosion control release is to drawing anchoring integral structure and construction method |
| CN109973126A (en) * | 2019-03-26 | 2019-07-05 | 中国矿业大学(北京) | The double release constant resistance supporting surrounding rock stability control methods of fender gob side entry driving |
| CN110886611A (en) * | 2019-12-06 | 2020-03-17 | 河南力行科创矿山技术开发有限公司 | Gob-side entry driving process for high-gas large-mining-height working face |
-
2020
- 2020-04-09 CN CN202010271511.2A patent/CN111535817A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SU1033758A1 (en) * | 1982-04-23 | 1983-08-07 | Шахта "Юбилейная" Производственного Объединения "Гидроуголь" | Method of protecting seam-type mine workings |
| WO2008087538A2 (en) * | 2007-01-18 | 2008-07-24 | Skarboevig Nils Mittet | A versatile grout bag type of underground support |
| CN102425439A (en) * | 2012-01-17 | 2012-04-25 | 中国矿业大学 | Method for reinforcing bidirectional staged stretched anchor cable of preset steel strand |
| CN107060758A (en) * | 2017-04-18 | 2017-08-18 | 辽宁工程技术大学 | A kind of section fender, which is stayed, sets construction method |
| CN108590723A (en) * | 2018-05-24 | 2018-09-28 | 中煤能源研究院有限责任公司 | Gob side entry driving fender erosion control release is to drawing anchoring integral structure and construction method |
| CN109973126A (en) * | 2019-03-26 | 2019-07-05 | 中国矿业大学(北京) | The double release constant resistance supporting surrounding rock stability control methods of fender gob side entry driving |
| CN110886611A (en) * | 2019-12-06 | 2020-03-17 | 河南力行科创矿山技术开发有限公司 | Gob-side entry driving process for high-gas large-mining-height working face |
Non-Patent Citations (2)
| Title |
|---|
| 申玉三 等: "钢管混凝土墩柱沿空留巷技术与工艺", 《钢管混凝土墩》 * |
| 黄万朋 等: "钢管混凝土支柱巷旁支护沿空留巷技术研究", 《中国矿业大学学报》 * |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112727460A (en) * | 2020-12-29 | 2021-04-30 | 山西石泉煤业有限责任公司 | Advanced pressure relief and corner fixing method for adjacent stope of high-gas mine |
| CN112983419A (en) * | 2021-03-18 | 2021-06-18 | 神华神东煤炭集团有限责任公司 | Working face coal pillar setting method |
| CN113137243A (en) * | 2021-03-27 | 2021-07-20 | 山东新巨龙能源有限责任公司 | Reinforcing method for corrosion-resistant interchange roadway of loose coal cylinder |
| CN113279795A (en) * | 2021-06-29 | 2021-08-20 | 辽宁工程技术大学 | Drilling, anchoring, digging and repairing rapid tunneling construction process method |
| CN113279795B (en) * | 2021-06-29 | 2023-10-31 | 辽宁工程技术大学 | Drilling, anchoring and repairing rapid tunneling construction process method |
| CN114198104A (en) * | 2021-12-15 | 2022-03-18 | 中天合创能源有限责任公司 | Long-distance coal pillar plugging and reinforcing method |
| CN115839249A (en) * | 2023-01-16 | 2023-03-24 | 煤炭科学技术研究院有限公司 | Method for arranging ultra-long working face double-measure roadway under sequential mining condition |
| CN115839249B (en) * | 2023-01-16 | 2023-04-18 | 煤炭科学技术研究院有限公司 | Method for arranging ultra-long working face double-measure roadway under sequential mining condition |
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