Technology of timbering of all alone of net of anchor of tunnel of loose and broken coal-bed studies deep

  • Younger brother 33 younger brother 3 period technology of timbering of all alone of anchorage net of tunnel of loose and broken coal-bed studies deep of coal science and technology Sun Xiaoming, he Manchao, feng Zengjiang (1. University of Chinese mining industry (Beijing) , coal mine of the station austral limited company of 1000832 Yan mine group, shandong Zou city 273500) the problem undertook an analysis, think this tunnel country rock is changed for tall stress joint compound model soft rock (HJ) , put forward specific compound model deformation force learns a mechanism to change countermeasure to design, after reaching section appearance to undertake the process optimizes a design to position of this tunnel driving, decided specific coupling timbering parameter. Tunnel use circumstance indicates the spot during actual construction observation and stoping, technique of timbering of coupling of anchorage net all alone can control the stability of country rock of this kinds of tunnel effectively.

    Add as what open our country colliery to collect deepness, the geomechanics environment with located country rock of the tunnel below the well is more complex, fall in tall stress action especially, condition of country rock of tunnel of the working face below the well becomes more loose and broken, how to solve deep the timbering problem of tunnel of loose and broken coal-bed, oneself become the difficult problem of a technology with at present medium exploitation of deep coal natural resources.

    This research uses anchorage net to all alone coupling timbering technology is opposite south 93 on 01 working face return station coal mine wind alley undertook timbering, obtained very good timbering result.

    1 project general situation 93 on 01 working face return coal mine of the station austral 1.1 projects geology wind alley is located in 9 select an area 3 on coal-bed, adopt level of lowest of the coal-bed inside the area: 3 go up A layer coal - 604.06 foundation project: National science fund is major project (50490270) ; Research of technology of Ministry of Education is great project (10405) ; National fund appoint project of fund of innovation research group (50221402) 78m. Rice area east, on the west, north is mixed 3 times by Yi hill, Ma Jialou respectively a surname fault cut of 3 big fault and into; Southern border is ancient efflorescent appear, mid 21 aperture fault is affected, geological construction is more complex.

    Tunnel place suffers crustal stress to basically be collected by susceptive of the place when gravitational, tectonic stress and stoping change load composition. According to spot project geology investigation and area crustal stress are analysed, the stress of leftover level construction with this area constant presence, but the impact is not big.

    Collect an area to come water form basically is roof water, aquifer full water is mixed for coal-bed coping sandstone dwarf Luo Tonggong lubricious sandstone (abbreviation red layer) aquifer. Among them, sandstone of 3 coal coping is cranny bear press aquifer, rich ability in swimming is poorer. Red layer is rich ability in swimming extremely not even cranny bear press aquifer, water penetration, rich ability in swimming and posture of well cropland the eastpart part, southwest department are compared all weaker.

    5~5.8m of structure of 1.2 cliff system, coal-bed structure is on soft the binary structure with next coal strong science and technology, if what show. Coal-bed upside is thick 2. 7~3.0m, inattentive and broken, bedding, cranny ten cent development, for inattentive structure; Bottom thick 0.7~3 calls coal body relatively complete, bedding, cranny relatively upside growth is less, for disintegrate structure. Coal-bed moves toward dip angle to be 10* left and right sides, trend inclination is 15* left and right sides. Bedding trend and 70* of tunnel trend included angle are controlled. According to country rock lens of microcosmic scanning report is analysed, this coal small cranny ten cent development.

    1.3 former timbering destroy section plane of geology of alley of on 01 93 wind and section position signal 93 on 01 working face answer the state design of initial stage of wind alley excavate is rectangular tunnel, wide 4m, tall 3 make had used anchorage net and steel to wear timbering form, along bottom driving. Construction initial stage, the destruction of tunnel the form basically has: (2) used anchorage rod of lead of reinforcing steel bar, unalterable still dig the situation that breaks down.

    (3) timbering of anchorage bridge net, lozenge net stiffness is insufficient, form bag shape to be out of shape, country rock leaves a layer, easy spontaneous combustion.

    (4) echelon steel wears timbering, coping country rock nods shape contact, country rock catchs fire easily from the layer.

    Collect mine of the coal that put a top to cause difficulty to put together, and be out of shape very big still.

    (6) in boring process, terrane is broken easy happening coal artillery piece and spontaneous combustion.

    Cause the cause of afore-mentioned phenomena, because coal-bed trend inclination is 15* ,basically be, so the tunnel of rectangular section has right side to see an end only, the bottom coal that Zun Bangliu has certain ply (dotted line part) , and the coal-bed bottom hard coal of binary structure has 3m left and right sides only, tunnel roof is the inattentive coal body of disintegrate structure for the most part, cause tunnel thereby hard timbering. Accordingly, choose proper tunnel section form and tunnel place, decide logical timbering way, become the problem that urgent need solves.

    2 anchorage nets all alone coupling timbering designs kind of 21 soft rock to judge 720m, can push know, the perpendicular and self-prossessed stress that place of place of this tunnel excavate suffers centers stress level for 9.4~14.4MPa highest can achieve 28.8MPa to destroy state investigation and theoretical analysis through spot project, can decide this coal-bed bate is critical deepness is controlled for 400m, this area already entered friend condition of deep tall stress. In the meantime, driving of bottom of edge of tunnel of this area coal-bed is extremely easy cave in, roof fall, timbering driving is very difficult.

    Integration analysis, can decide body of this project cliff is HJ (tall stress - joint is changed) compound model soft rock.

    2.2 deformation force learn a mechanism to reach its mechanical countermeasure design passes investigation and study of spot project geology and indoor physics mechanical experiment research, mechanical theory analyses project of combinative soft rock, 93 on 01 working face answer wind tunnel country rock to be out of shape mechanical mechanism IcbdIcc compound model deformation force learns a mechanism, namely: Have small cranny to expand (Ic) , gravity and project slant stress enlarge look is out of shape (Bd) with bedding tendency model (Icc) compound model be out of shape mechanism. Among them the mechanical countermove that each deformation force learns mechanism place to adopt is: (1) Ic: Technology of timbering of anchorage net coupling (compound tray) .


    2.3 processes optimize a design to pass the numeric imitate of limits of divisional to the plasticity after excavate of tunnel of different section appearance cloth, to score analyse its can see as a result (A, B) , the plasticity area limits after vaulted tunnel excavate is less than straight wall semicircle apparently rectangular tunnel. Accordingly, should choose straight wall semicircle vaulted for optimal section appearance.

    Pass the numeric imitate of limits of divisional to the plasticity after excavate of different tunnel position cloth, to score analyse its can see as a result (B, C) , the plasticity area limits after broken bottom excavate is less than edge bottom excavate apparently. Accordingly, should choose to defeat bottom excavate to be tunnel optimal layout means.

    In the meantime, use straight wall semicircle driving of broken bottom of vaulted tunnel section, make tunnel is in finer country rock structure to fall, be helpful for the lead during tunnel stoping safeguarding not only, more important is the trigonometry coal loss that avoided to be caused along bottom driving, be helpful for the propulsion of stoping working face.

    In affirmatory tunnel optimal section appearance reachs optimal tunnel overall arrangement hind, according to spot theory analysis, numeric imitate analyses a result, combine the feasibility that the scene operates actually, can decide 93 on 01 working face answer wind alley compound model deformation force learns a mechanism change a course, if what show.

    Parameter of 2.4 coupling timbering is designed 2.4.1 the first time theoretical calculation and numeric imitate analyse basis of coupling timbering parameter, decide 93 on 01 working face answer wind alley the first time coupling timbering parameter is as follows: (1) tunnel section form is straight wall semicircle vaulted, the fence is high for 93 on 01 working face answer wind alley to bury deep (H) for 470 coal science and technology compound model deformation force learns a mechanism change process signal 3 beautiful shape are decorated, the platoon is apart from between all be 1m. The root sells pole 2, the requirement sells lever every to sell firm force to be 100~130MN. ) , metallic tray is outside.

    5mm reinforcing steel bar solders to machine and be become (80mm80mm) , gauze norms is built for 1100mm 1100mm> receive length 100mm to chase buckle join.

    1800mm, the platoon is apart from between all be 1m. Place of key of parameter of timbering of 2 2.4.2 coupling can decide according to numeric imitate result, namely the position that shearing stress of tunnel roof generation amasses. According to numeric imitate result, the crucial position that 93 on 01 working face answer wind alley roof to sell all alone timbering is roof two shoulders ministry () . According to analysis of theoretical calculation and numeric imitate result, can decide 93 on 01 working face answer wind alley anchor cable 2 times coupling timbering parameter () for: Anchor cable of 24mm steel skeining thread, length 5. 5m, appear length 300mm, rice coils with colophony medicine termination anchor originallies, 93 on 01 working face answer distributinging signal of stress of excavate of bottom of alley point out signal of parameter of design of section of wind alley timbering medicine of colophony of CK2350 of position of space of timbering of 6 ― anchorage lever coils and K2350 colophony medicine coils each 1, the platoon between anchor cable is apart from for 2 2000mm, 3 flowers are decorated.

    Armor plate is made.

    (3) because complete coal tunnel produces tall stress to corrode a phenomenon,observe not easily, because this is in actual project, according to particular case, but construction of working face of follow closely driving, also but construction of lag driving working face, but lag distance cannot be more than 20m. Among them, working face of follow closely driving carries out anchor cable timbering, tighten force to be 98kN beforehand; Plasticity of excavate of tunnel of 20m of lag driving working face is divisional cloth - plasticity of excavate of bottom of rectangular tunnel edge is divisional cloth; Semicircle of B ― straight wall is vaulted plasticity of excavate of tunnel edge bottom is divisional cloth; Straight wall semicircle is vaulted science and technology of divisional cloth coal buries plasticity of tunnel edge bottom deep / M is different bury measure a dot greatly to be the same as - time displacement - the test that buries deep curve 4 years, tunnel figuration is good, roof gets controlling. In stoping process, in dynamic pressure the influence falls, tunnel is bigger without generation be out of shape. Came true successfully to be in deep is broken driving of bottom of coal-bed tunnel edge, achieved expect an end, economic benefits is remarkable.