CN109882206B - Multi-support cooperative method for controlling coal mine broken surrounding rock - Google Patents
Multi-support cooperative method for controlling coal mine broken surrounding rock Download PDFInfo
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Abstract
The invention discloses a multi-support cooperative method for controlling coal mine broken surrounding rocks, which comprises the steps of firstly adopting a flexible shed frame to support the surrounding rocks in the support time, then carrying out grouting cementation on the broken surrounding rocks, and finally adopting extensible anchor rods to anchor the cemented broken surrounding rocks and original complete surrounding rocks; on the supporting space, the contractible shed frame supports and limits the initial deformation of the surface of the surrounding rock, meanwhile, the surface of the surrounding rock adopts an anti-leakage flexible layer to protect the surface and prevent the leakage of grouting slurry, the shallow broken surrounding rock of the surrounding rock is cemented by grouting, and then the shallow cemented broken surrounding rock and the original complete surrounding rock are anchored and connected by an extensible anchor rod towards the deep part; in the supporting strength, the contractible shed frame supports the gravity of the surrounding rocks of the crushing part, so that the crushing range is not rapidly expanded, the integral structure of the cemented surrounding rocks can be formed after the grouting and the cementation of the crushed surrounding rocks, the strength can bear the gravity of the self, the anchoring strength of the extensible anchor rod is determined according to the deformation rate of the surrounding rocks, and the purpose of cooperatively controlling the stable deformation of the surrounding rocks by multiple supports is achieved.
Description
Technical Field
The invention relates to a supporting method for coal mine broken surrounding rocks, in particular to a multi-supporting cooperative method for controlling the coal mine broken surrounding rocks.
Background
Deep mining is an important subject facing the utilization of coal resources in China at present. Under the condition of high stress at the deep part, surrounding rocks around the roadway are rapidly crushed after excavation and unloading of the roadway, and under the influence of stoping disturbance of a working face, a crushing area of the surrounding rocks of the roadway is continuously expanded to form a large-range crushing area. If no effective control measures are taken, the deep tunnel is easy to be damaged by large deformation and instability. The current engineering practice shows that the existing support theory and technology can not be applied to the control of large-range wall rock crushing of deep roadways, and specifically comprises the following steps: in the aspect of an active support theory and a support structure (namely, the support is realized by adopting an anchor rod and an anchor cable): the method has the problems of insufficient supporting strength, too small supporting range, insufficient coordination and deformation capacity of a supporting structure and the like. Due to the problems, a large number of anchor rods and anchor cables are broken or fall along with the broken surrounding rocks. In addition, the elongation of the existing active supporting structures such as anchor rods and anchor cables is generally difficult to adapt to the deformation of deep large-range broken surrounding rocks. In the aspect of passive supporting theory and structure (namely, adopting a shed frame for supporting): through on-site investigation and theoretical calculation, it is found that both the rigid canopy frame and the contractible canopy frame are difficult to counter against huge ground stress, and due to the action of the ground stress, the deformation of deep broken surrounding rocks is large, the deformation is uneven, and finally the breakage, distortion and fracture of the canopy frame are caused. In a whole view, the main problems of the existing support theory are that the self-bearing capacity of the surrounding rock at the deep part of the roadway and the shallow surface cannot be fully adjusted, and a support-surrounding rock cooperative bearing structure cannot be formed, so that the secondary stability of the high-stress broken surrounding rock cannot be realized.
Disclosure of Invention
Aiming at the problems in the prior art, the invention provides a multi-support cooperative method for controlling coal mine broken surrounding rocks, which adopts a shed frame support, grouting and cementing the surrounding rocks and anchor rod anchoring cooperative bearing, thereby ensuring the stability of high-stress broken surrounding rocks.
In order to achieve the purpose, the invention adopts the technical scheme that: a multi-support cooperative method for controlling coal mine broken surrounding rock comprises the following specific steps:
A. and (3) supporting by using a shed frame:
a. in the process of tunneling a roadway, when a hollow top area formed after cutting of a tunneling machine is used, a plurality of seamless steel pipes are used as temporary supports of a front canopy; transversely arranging 1-2U-shaped steel beams above the temporary support of the forepoling beam, sequentially laying a metal mesh and an anti-seepage flexible layer on the steel beams, and then filling and fastening gaps between the anti-seepage flexible layer and surrounding rocks of a roadway roof by using wood wedges or bamboo chips; after the range of the empty roof area reaches the placing space of a contractible shed frame along with the cutting of the tunneling machine, applying a certain pre-supporting force to the empty roof area by adopting the contractible shed frame; adopting an anti-skid device in the inclined drift;
b. installing a plurality of embedded steel bars with the length of more than 1 meter on the wall of the roadway, wherein the embedded depth of the steel bars is not less than 2/3 of the total length; when the forestope moves forwards, one end of each seamless steel pipe in the forestope is fixedly inserted and fixed with the exposed part of the embedded steel bar, and then the other end of each seamless steel pipe is fixed by adopting a scraper chain to finish the forward movement fixation of the forestope;
c. after the forestope is fixed, workers enter the temporary support area to build a flexible shed frame, and the flexible shed frame is used for stably supporting the empty roof area and then removing the temporary support; the distance between the flexible pergolas is determined according to different surrounding rock conditions and the required supporting resistance;
d. according to the change rule of stress in the laboratory measurement shed frame dislocation process, the change of the support resistance on the shed frame is judged in real time, and then the support resistance of the shed frame is adjusted by screwing or loosening according to the requirement of the support resistance of the shed frame;
B. grouting and cementing the surrounding rock:
i, after roadway driving is completed, selecting a rock sample of on-site broken surrounding rocks, carrying out grouting cementation test in a laboratory, obtaining the strength of the broken surrounding rocks after cementation corresponding to different cementation proportions, and finally determining the proportion of grouting cementation so that the strength of a cemented rock body formed by grout and the surrounding rocks is not lower than the strength of the original surrounding rocks;
II, arranging a certain number of shallow hole grouting pipes on the shallow part of the surrounding rock supported by the retractable canopy frame, and performing grouting cementation on the broken surrounding rock on the shallow surface of the roadway through each shallow hole grouting pipe by adopting the grouting cementation proportion determined in the step I until the broken surrounding rock from the surface of the surrounding rock to the shallow part is completely cemented, and stopping to enable the broken surrounding rock to form a surrounding rock cemented rock body;
C. anchoring the anchor rod:
① after the wall rock cemented rock mass is formed, drilling a borehole in the wall rock between the two yieldable pergolas, and adopting an extensible anchor rod to extend into the borehole for end anchoring;
② stress values of the extensible anchor rods and the retractable shed are monitored in real time, and then the prestress of the extensible anchor rods and the retractable shed is adjusted to enable the stress on the two supporting structures to be close to each other, and after the stress change and the deformation amount tend to be consistent, the adjusting process is completed, and finally the supporting system with the cooperation of shed supporting, grouting and cementing of surrounding rocks and anchor rod anchoring is realized.
And further, controlling the deformation of the surface of the surrounding rock of the two sides of the roadway in the same manner as that of the support of the empty roof area in the step a.
Further, the scraper chain is oval, and each seamless steel pipe is provided with at least 2 scraper chains.
Furthermore, the retractable canopy frame is an arch-shaped retractable canopy frame or a trapezoid retractable canopy frame.
Compared with the prior art, the invention adopts the combination of shed frame support, grouting and cementing surrounding rock and anchor rod anchoring,
1) in the supporting time, a retractable canopy frame is firstly adopted to support surrounding rocks which are broken after entry driving. And then, performing superficial grouting on the broken surrounding rock part. And finally, anchoring the cemented and fractured surrounding rock and the original complete surrounding rock by using an extensible anchor rod.
2) On the supporting space, the contractible shed frame is adopted to support and limit the initial deformation of the surface of the surrounding rock, and meanwhile, the surface of the surrounding rock is protected by an anti-leakage flexible layer to prevent the leakage of grouting slurry of shallow surrounding rock. And grouting and cementing the shallow broken surrounding rock of the surrounding rock, and anchoring and connecting the shallow cemented broken surrounding rock and the original complete surrounding rock by adopting an extensible anchor rod towards the deep part.
3) On the support strength, the contractible shed frame supports the gravity of the surrounding rock at the crushing part, so that the crushing range is not expanded quickly. The whole structure of the cemented surrounding rock can be formed after the grouting and the cementation of the broken surrounding rock, and the strength can bear the self gravity. The anchoring strength of the extensible anchor rod is determined according to the deformation rate of the surrounding rock, and the purpose of controlling the stable deformation of the surrounding rock is achieved.
4) On the integral supporting structure, after the three supporting forms are applied, the axial force on the anchor rod is in cooperative consistency with the supporting resistance of the shed frame, and the deformation of the grouting and cementing surrounding rock is in cooperative consistency with the contractible amount of the shed frame and the extension amount of the anchor rod; finally realizing the cooperative integration of shed frame support, grouting and cementing surrounding rock and anchor rod anchoring to control the broken surrounding rock at the deep part of the coal mine.
In the process of bearing the surrounding rock of the roadway by the integral structure, the initial high supporting resistance comes from the canopy frame support and the structural support of the crushed surrounding rock restructured after cementation-anchoring, and the cooperative bearing and deformation capacity is realized due to the self-discontinuity of the inside of the crushed surrounding rock, the contractibility of the supporting structure and the extensibility of the anchoring structure. In addition, as the broken surrounding rocks are cemented and anchored to a certain extent, the broken surrounding rocks can form a large block (such as an anchoring string-shaped body) and can be mutually occluded in the process of compression and contraction, and an arch-like or combined rock beam type bearing structure can be formed, so that the aim of supporting the broken surrounding rocks is fulfilled.
Drawings
Figure 1 is a cross-sectional view of a temporary support according to the present invention;
FIG. 2 is a top view of FIG. 1;
FIG. 3 is a schematic representation of the yieldable shelving support stage of the invention;
FIG. 4 is a schematic representation of the invention during the cementing stage of the grouting;
FIG. 5 is a schematic illustration of the present invention in the bolt anchoring phase;
FIG. 6 is a schematic view of the construction of an integral support using trapezoidal yieldable shelving;
fig. 7 is a schematic structural view of the integral support by using the arch-shaped yieldable canopy frame.
In the figure: 1. embedding reinforcing steel bars in advance; 2. a leakage-resistant flexible layer; 3. a scraper chain; 4. pressing the net material; 5. a U-shaped steel beam; 6. a metal mesh; 7. seamless steel pipes; 8. surrounding rocks of a roadway floor; 9. a collapsible canopy frame; 10. crushing surrounding rocks; 11. surrounding rocks at two sides of the roadway; 12. surrounding rocks of a roadway roof; 13. cementing the rock mass with surrounding rocks; 14. shallow hole grouting pipes; 15. an extendable anchor rod; 16. the anchor anchoring end of the anchor rod can be extended.
Detailed Description
The present invention will be further explained below.
As shown in the figure, the method comprises the following specific steps:
A. and (3) supporting by using a shed frame:
a. in the process of tunneling a roadway, when a hollow top area is formed after the cutting of the tunneling machine, a plurality of seamless steel pipes 7 are used as temporary supports of a front canopy; transversely arranging 1-2U-shaped steel beams 5 above the temporary support of the forepoling bar, sequentially laying a metal net 6 and an anti-leakage flexible layer 2 (made of anti-leakage flexible materials such as air duct cloth) on the steel beams, and then filling and fastening gaps between the anti-leakage flexible layer 2 and the surrounding rocks 12 of the roadway roof by using a net pressing material 4 (such as wood wedges or bamboo sheets); when the range of the empty roof area reaches the placing space of a contractible shed frame 9 along with the cutting of the heading machine, the contractible shed frame 9 is adopted to apply a certain pre-supporting force to support the empty roof area; adopting an anti-skid device in the inclined drift;
b. installing a plurality of embedded steel bars 1 with the length of more than 1 meter on the wall of the roadway, wherein the embedded depth of the steel bars is not less than 2/3 of the total length; when the forestope moves forwards, one end of each seamless steel tube 7 in the forestope is fixedly inserted and fixed with the exposed part of the embedded steel bar 1, and then the other end of each seamless steel tube 7 is fixed by adopting the scraper chain 3, so that the forestope is moved forwards and fixed;
c. after the forestope is fixed, the staff enters the temporary support area to build a flexible shed 9, and the flexible shed 9 supports the empty roof area stably and removes the temporary support; the distance between the flexible pergola 9 is determined according to different surrounding rock conditions and the required supporting resistance;
d. according to the change rule of stress in the laboratory measurement shed frame dislocation process, the change of the support resistance on the shed frame is judged in real time, and then the support resistance of the shed frame is adjusted by screwing or loosening according to the requirement of the support resistance of the shed frame;
B. grouting and cementing the surrounding rock:
i, after roadway driving is completed, selecting a rock sample of the on-site broken surrounding rock 10, carrying out grouting cementation test in a laboratory, obtaining the cemented strength of the broken surrounding rock 10 corresponding to different cementing proportions, and finally determining the cementing proportion so that the strength of a cemented rock body formed by grout and surrounding rock is not lower than the strength of the original surrounding rock;
II, arranging a certain number of shallow hole grouting pipes 14 at the shallow part of the surrounding rock supported by the retractable canopy frame 9, and then performing grouting cementation on the broken surrounding rock 10 on the shallow surface of the roadway by adopting the grouting cementation proportion determined in the step I through each shallow hole grouting pipe 14 (the grouting pressure is not too large so as to avoid bulging damage of the surface of the surrounding rock), and stopping until the broken surrounding rock 10 from the surface of the surrounding rock to the shallow part is completely cemented, so that the broken surrounding rock forms a surrounding rock cemented rock body 13;
C. anchoring the anchor rod:
① after the wall rock cemented rock mass 13 is formed, drilling a hole in the wall rock between two flexible shelves 9, and adopting an extensible anchor rod 15 to extend into the hole for anchoring the end part, wherein the length of the extensible anchor rod 15 is determined according to the crushing range of the wall rock, if the crushing range is too large, the extensible anchor rod 15 capable of being extended is adopted, the extensible anchor rod 15 needs to apply certain prestress but not exceed the stress value for extending the extensible anchor rod 15, the extensible anchor rod 15 is the existing structure, has certain supporting resistance and simultaneously has larger elongation;
② real-time monitoring the stress value of the extensible anchor rod 15 and the contractible shed 9, adjusting the prestress of the extensible anchor rod 15 and the contractible shed 9 to make the stress on the two supporting structures approach, completing the adjusting process after the stress change and the deformation amount tend to be consistent, and finally realizing the cooperative integrated bearing system of the shed support, the grouting and cementing surrounding rock and the anchor rod anchoring.
And further, controlling the deformation of the surface of the surrounding rock of the two sides of the roadway in the same manner as that of the support of the empty roof area in the step a.
Further, the scraper chain 3 is oval, and each seamless steel pipe 7 is provided with at least 2 scraper chains.
Further, the retractable canopy frame 9 is an arch-shaped retractable canopy frame or a trapezoid-shaped retractable canopy frame.
Claims (4)
1. A multi-support cooperative method for controlling coal mine broken surrounding rock is characterized by comprising the following specific steps:
A. and (3) supporting by using a shed frame:
a. in the process of tunneling a roadway, when a hollow top area formed after cutting of a tunneling machine is used, a plurality of seamless steel pipes are used as temporary supports of a front canopy; transversely arranging 1-2U-shaped steel beams above the temporary support of the forepoling beam, sequentially laying a metal mesh and an anti-seepage flexible layer on the steel beams, and then filling and fastening gaps between the anti-seepage flexible layer and surrounding rocks of a roadway roof by using wood wedges or bamboo chips; after the range of the empty roof area reaches the placing space of a contractible shed frame along with the cutting of the tunneling machine, applying a certain pre-supporting force to the empty roof area by adopting the contractible shed frame;
b. installing a plurality of embedded steel bars with the length of more than 1 meter on the wall of the roadway, wherein the embedded depth of the steel bars is not less than 2/3 of the total length; when the forestope moves forwards, one end of each seamless steel pipe in the forestope is fixedly inserted and fixed with the exposed part of the embedded steel bar, and then the other end of each seamless steel pipe is fixed by adopting a scraper chain to finish the forward movement fixation of the forestope;
c. after the forestope is fixed, workers enter the temporary support area to build a flexible shed frame, and the flexible shed frame is used for stably supporting the empty roof area and then removing the temporary support; the distance between the flexible pergolas is determined according to different surrounding rock conditions and the required supporting resistance;
d. according to the change rule of stress in the laboratory measurement shed frame dislocation process, the change of the support resistance on the shed frame is judged in real time, and then the support resistance of the shed frame is adjusted by screwing or loosening according to the requirement of the support resistance of the shed frame;
B. grouting and cementing the surrounding rock:
i, after roadway driving is completed, selecting a rock sample of on-site broken surrounding rocks, carrying out grouting cementation test in a laboratory, obtaining the strength of the broken surrounding rocks after cementation corresponding to different cementation proportions, and finally determining the proportion of grouting cementation so that the strength of a cemented rock body formed by grout and the surrounding rocks is not lower than the strength of the original surrounding rocks;
II, arranging a certain number of shallow hole grouting pipes on the shallow part of the surrounding rock supported by the retractable canopy frame, and then grouting and cementing the surface of the surrounding rock of the roadway and the broken surrounding rock of the shallow part through each shallow hole grouting pipe according to the grouting and cementing proportion determined in the step I until the broken surrounding rock from the surface of the surrounding rock to the shallow part is completely cemented, and stopping to enable the broken surrounding rock to form a surrounding rock cemented rock body;
C. anchoring the anchor rod:
① after the wall rock cemented rock mass is formed, drilling a borehole in the wall rock between the two yieldable pergolas, and adopting an extensible anchor rod to extend into the borehole for end anchoring;
② stress values of the extensible anchor rods and the retractable shed are monitored in real time, and then the prestress of the extensible anchor rods and the retractable shed is adjusted to enable the stress on the two supporting structures to be close to each other, and after the stress change and the deformation amount tend to be consistent, the adjusting process is completed, and finally the supporting system with the cooperation of shed supporting, grouting and cementing of surrounding rocks and anchor rod anchoring is realized.
2. The multi-support cooperative method for controlling coal mine crushing surrounding rock according to claim 1, wherein in the step a, deformation of the surrounding rock surfaces of the two sides of the roadway is controlled by the same method as that of the support of the empty roof area.
3. The multi-support cooperative method for controlling coal mine crushing surrounding rock according to claim 1, wherein the scraper chain is elliptical in shape, and not less than 2 scraper chains are provided on each seamless steel pipe.
4. The multi-support collaborative method for controlling coal mine crushing surrounding rocks according to claim 1, wherein the retractable canopy is an arch-shaped retractable canopy or a trapezoid-shaped retractable canopy.
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| JP2758149B2 (en) * | 1995-11-01 | 1998-05-28 | 住友大阪セメント株式会社 | Invert structures |
| CN103174435B (en) * | 2013-02-26 | 2014-12-03 | 中国矿业大学(北京) | Roadway support method adopting U-shaped canopy frame support structure body |
| SE543647C2 (en) * | 2014-12-15 | 2021-05-18 | Cn Railway Siyuan Survey & Des | Method for constructing extra-large variable cross section tunnel |
| CN104895583B (en) * | 2015-04-28 | 2017-02-01 | 河南理工大学 | Tunnel surrounding rock control method combining pressure relief and slip-casting reinforcement |
| CN105134269B (en) * | 2015-08-17 | 2017-05-10 | 河南理工大学 | Control method for roadway surrounding rock achieving cooperative load bearing by enabling anchor cables to penetrate through sheds |
| CN106761867A (en) * | 2016-12-23 | 2017-05-31 | 四川广旺能源发展（集团）有限责任公司 | High-dipping surrounding rock of actual mining roadway stabilization supporting facility and support process |
| CN106948842A (en) * | 2017-03-31 | 2017-07-14 | 兖州煤业股份有限公司 | A kind of scaffolding structure for being used under thin dirt band cover coal road |
| CN109372556B (en) * | 2018-09-30 | 2020-08-25 | 淮阴工学院 | Sandwich arch suitable for high-stress soft rock tunnel surrounding rock support and construction method |
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