Driving Construction Technology under the Coal Roof in the Air Return Roadway

Abstract

The present invention provides a tunneling construction process under the coal roof of a ventilation lane, which belongs to the technical field of tunneling construction. It comprises the following steps: S1. Lowering the tunnel construction layer, changing the bottom break of 1.5m to the right side following the coal bottom and the left side breaking the bottom 200mm, manually finding the beam road, and the tunnel boring machine lags behind and digs the bottom 10-15m; S2. Using a small excavator to deliver the goods; S3. Grouting shallow holes along the empty side wall, and evenly arranging two 1m long grouting anchor rods in each shed for grouting reinforcement; S4. Construction of the right side following the coal bottom, breaking the bottom 200mm on the left side, and using anchor net spraying support for the rock section after the tunnel boring machine digs the bottom. The present invention effectively controls the roof by lowering the tunnel construction layer and leaving a construction platform at the head, thereby reducing the possibility of roof falling accidents during tunneling under the coal roof of the ventilation lane; by using a small excavator to deliver the goods, the tunneling construction efficiency is improved and the labor intensity of employees is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of tunnel excavation construction, in particular to a tunnel excavation construction process under a coal roof in a ventilation tunnel. Background Art

[0002] There are still some problems in the design and construction of ventilation tunnels:

[0003] 1. The bottom breaking height is 1.5m. The vibration of the fully-mechanized tunneling and cutting disturbs the coal roof, and no construction platform can be reserved for the fully-mechanized tunneling and cutting head. In addition, the roadway height is 3.6m, making the roof and end face management difficult.

[0004] 2. Manual excavation and delivery at the upper part of the head is labor-intensive and has low efficiency;

[0005] 3. The pressure along the airside is high and the roadway has certain deformation;

[0006] 4. Due to the bottom breaking construction and the natural inclination of the coal seam, there are more bottom breaks on the left side, and the construction progress of the shed legs is slow. Summary of the Invention

[0007] In order to make up for the above deficiencies, the present invention provides a construction process for tunneling under the coal roof of a ventilation lane.

[0008] The embodiment of the present invention provides a construction process for tunneling under the coal roof of a ventilation lane, comprising the following steps:

[0009] S1. Lower the tunnel construction level, changing the bottom break to 1.5m on the right side and 200mm on the left side. Manually locate the beam path, and lag the tunnel boring machine 10-15m behind to shovel the bottom.

[0010] S2. Use small excavator to ship goods;

[0011] S3. Grout shallow holes along the side walls of the empty space, and evenly arrange two 1m long grouting anchors in each shed for grouting reinforcement;

[0012] S4. Construction is carried out on the right side following the coal bottom, and on the left side, the bottom is broken 200mm and short legs are planted. In the later stage, the rock section after the tunnel boring machine digs the bottom is supported by anchor net spraying.

[0013] In the above implementation process, by lowering the construction layer of the tunnel and leaving a construction platform at the head, the roof is effectively controlled, reducing the possibility of roof falling accidents during excavation under the coal roof of the wind tunnel; by using small excavators for delivery, the excavation construction efficiency is improved and the labor intensity of employees is reduced; by grouting shallow holes along the side wall, the surrounding rock is effectively reinforced, so that the maximum deformation along the side is less than 100mm; by following the bottom of the right side and planting short legs on the left side to break the bottom by 200mm, the efficiency of the head-on construction is improved. After the rear road comprehensive excavator shovels the bottom, the left side is supported by anchor mesh spraying, and the tunnel section is effectively utilized without waste.

[0014] In a specific implementation scheme, the step S1 also includes: preparatory work and the advancement and arrangement of the power system and the ventilation system. The preparatory work includes equipment installation, personnel preparation, and material preparation. The advancement and arrangement of the power system and the ventilation system are used as energy and safety guarantees during the rock tunnel excavation process, and need to be extended forward after the working face of each rock tunnel is advanced a certain distance.

[0015] In the above implementation process, interference preparation is required without affecting normal construction to prevent work stoppage due to lack of necessary equipment and materials.

[0016] In a specific embodiment, the ventilation system is used to ventilate and remove dust in the tunnel, and the dust removal work includes the following steps:

[0017] S101. Air is forced into the duct. After combining with dust, the dust-laden air is drawn into the dust collector, silenced by the muffler section, filtered by the filter section, and then passes through the rear end of the dust collector. The air volume supplied to the duct is Q', and the dust-laden air volume extracted from the dust collector is Q.

[0018] S102. The air control device changes the flow direction of the purified clean air, so that a portion of the clean air volume Q1 is pressed into the dust in the roadway, while another portion of the clean air volume Q2 is diffused toward the rear end of the dust collector. Based on the law of flow conservation, it can be obtained that during operation, Q = Q1 + Q2;

[0019] S103. The air volume Q extracted by the dust collector is greater than Q', and the clean air volume Q1 pressed into the dust collector is equal to Q-Q'. At this time, a negative pressure effect is formed at the front end of the dust collector. At the same time, the wall attachment effect of the airflow is used to change the airflow of this part of the clean air volume Q1 into a rotating airflow along the tunnel wall, and blow it toward the tunnel wall and the entire tunnel section at a certain rotation speed, continuously advancing head-on to prevent the dust-laden airflow from spreading to the rear end of the dust collector.

[0020] In a specific implementation scheme, the air volume of Q1 in S103 is changed by adjusting the structural parameters of the wind control device, and the wind control device includes a servo motor, fan blades and a control module. The control module is used to control the speed of the servo motor, and the servo motor is transmission-connected to the fan blades.

[0021] In a specific embodiment, the method for grouting reinforcement of the grouting anchor in S3 comprises the following steps:

[0022] S301 will be floating in the use of tunnel boring machine or blasting way out of the tunnel wall of the broken rock, coal cleaned up, with a jackhammer stripping the tunnel wall of the dangerous rock brush out of the rough section of the tunnel;

[0023] S302. The inner wall of the roadway is sprayed with a shotcrete machine to obtain a concrete spray layer;

[0024] S303. Use compressed air or water to remove rock dust from the grouting anchor hole. Add anchoring agent and insert the anchor rod to anchor the grouting anchor rod into the surrounding rock. Seal the hole with cement.

[0025] S304. Use a grouting machine to inject grout into the surrounding rock through the grouting anchor rod. After the grouting is completed, seal and tighten the grouting anchor rod tray in a timely manner.

[0026] S305. After grouting is completed, testing is carried out.

[0027] In a specific embodiment, when the pump pressure in the surrounding rock reaches 1.4-3.2 MPa or grouting occurs in adjacent boreholes in S304, grouting is stopped immediately, and the grouting time for a single hole is 15-35 minutes.

[0028] In a specific embodiment, the grouting slurry in S304 uses cement slurry with a water-cement ratio of cement to water of 0.7:1.0 to 1:1.0.

[0029] In a specific embodiment, the method of using anchor mesh spraying support in S4 includes the following steps:

[0030] S401. Clear the rock section of pumice;

[0031] S402. Initial spraying of the roadway with plain concrete;

[0032] S403. Drill several rows of anchor holes perpendicular to the tunnel rock wall;

[0033] S404. Install resin anchors;

[0034] S405. Use steel bars for meshing;

[0035] S406. Install double reinforcement bars from one end of the same row of anchors to the other. The double reinforcement bars consist of two parallel steel bars, one on each side of the anchor, with a distance of 50 mm between them. The bars are fixed together with steel bars, and each bar is fixedly connected to the anchor support plate.

[0036] S407. Prestress the anchor rods and then spray concrete for the second time.

[0037] In a specific embodiment, the thickness of the sprayed concrete in S402 is 40-60 mm, and the thickness of the secondary sprayed concrete in S407 is 90-110 mm.

[0038] Beneficial effects:

[0039] 1. By lowering the tunnel construction layer and leaving a construction platform at the head, the roof is effectively controlled, reducing the possibility of roof collapse accidents during excavation under the coal roof of the ventilation tunnel;

[0040] 2. By using small excavators for delivery, the efficiency of excavation construction is improved and the labor intensity of employees is reduced;

[0041] 3. Through shallow hole grouting along the side wall, the surrounding rock is effectively reinforced, making the maximum deformation along the side less than 100mm;

[0042] 4. By following the bottom of the right side of the head and planting short legs on the left side to break the bottom by 200mm, the efficiency of the head-on construction is improved. After the rear road tunneling machine shovels the bottom, the left side is supported by anchor net spraying, and the tunnel section is effectively utilized without waste. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0044] Figure 1 It is a flow chart provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0045] The technical solutions in the embodiments of the present invention will be described below with reference to the accompanying drawings in the embodiments of the present invention.

[0046] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0047] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are also within the scope of protection of the present invention.

[0048] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0049] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0050] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0051] In the present invention, unless otherwise expressly specified or limited, terms such as "mounted," "connected," "connect," and "fixed" should be understood broadly. For example, they may refer to fixed connection, detachable connection, or integration; they may refer to direct connection or indirect connection through an intermediate medium; they may refer to internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0052] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0053] See also Figure 1 The present invention provides a construction process for tunneling under the coal roof of a ventilation lane, comprising the following steps:

[0054] S1. Lower the tunnel construction level, changing the bottom break to 1.5m on the right side and 200mm on the left side. Manually locate the beam path, and lag the tunnel boring machine 10-15m behind to shovel the bottom.

[0055] S2. Use small excavator to ship goods;

[0056] S3. Grout shallow holes along the side walls of the empty space, and evenly arrange two 1m long grouting anchors in each shed for grouting reinforcement;

[0057] S4. Construction is carried out on the right side following the coal bottom, and on the left side, the bottom is broken 200mm and short legs are planted. In the later stage, the rock section after the tunnel boring machine digs the bottom is supported by anchor net spraying.

[0058] In the scheme of the present invention, the step before S1 also includes: preparatory work and the advancement and arrangement of the power system and the ventilation system. The preparatory work includes equipment installation, personnel preparation and material preparation. The advancement and arrangement of the power system and the ventilation system are used as energy and safety guarantees during the rock tunnel excavation process. They need to be extended forward after the working face of the rock tunnel is advanced a certain distance each time. Interference preparation is required without affecting normal construction to prevent work stoppage due to lack of necessary equipment and materials.

[0059] In the solution of the present invention, in order to facilitate ventilation and dust removal in the tunnel, the ventilation system is used to ventilate and remove dust in the tunnel, and the dust removal work includes the following steps:

[0060] S101. Air is forced into the duct. After combining with dust, the dust-laden air is drawn into the dust collector, silenced by the muffler section, filtered by the filter section, and then passes through the rear end of the dust collector. The air volume supplied to the duct is Q', and the dust-laden air volume extracted from the dust collector is Q.

[0061] S102. The air control device changes the flow direction of the purified clean air, so that a portion of the clean air volume Q1 is pressed into the dust in the roadway, while another portion of the clean air volume Q2 is diffused toward the rear end of the dust collector. Based on the law of flow conservation, it can be obtained that during operation, Q = Q1 + Q2;

[0062] S103. The air volume Q extracted by the dust collector is greater than Q', and the clean air volume Q1 pressed into the dust collector is equal to Q-Q'. At this time, a negative pressure effect is formed at the front end of the dust collector. At the same time, the wall attachment effect of the airflow is used to change the airflow of this part of the clean air volume Q1 into a rotating airflow along the tunnel wall, and blow it toward the tunnel wall and the entire tunnel section at a certain rotation speed, continuously advancing head-on to prevent the dust-laden airflow from spreading to the rear end of the dust collector.

[0063] In the solution of the present invention, the air volume of Q1 in S103 is changed by adjusting the structural parameters of the wind control device, and the wind control device includes a servo motor, fan blades and a control module. The control module is used to control the speed of the servo motor, and the servo motor is transmission-connected to the fan blades.

[0064] In the solution of the present invention, the method for grouting reinforcement of the grouting anchor rod in S3 comprises the following steps:

[0065] S301 will be floating in the use of tunnel boring machine or blasting way out of the tunnel wall of the broken rock, coal cleaned up, with a jackhammer stripping the tunnel wall of the dangerous rock brush out of the rough section of the tunnel;

[0066] S302. The inner wall of the roadway is sprayed with a shotcrete machine to obtain a concrete spray layer;

[0067] S303. Use compressed air or water to remove rock dust from the grouting anchor hole. Add anchoring agent and insert the anchor rod to anchor the grouting anchor rod into the surrounding rock. Seal the hole with cement.

[0068] S304. Use a grouting machine to inject grout into the surrounding rock through the grouting anchor rod. After the grouting is completed, seal and tighten the grouting anchor rod tray in a timely manner.

[0069] S305. After grouting is completed, testing is carried out.

[0070] In the solution of the present invention, when the pump pressure in the surrounding rock reaches 1.4-3.2 MPa or grouting occurs in adjacent boreholes in S304, grouting is stopped immediately, and the grouting time for a single hole is 15-35 minutes.

[0071] In specific settings, the grouting slurry in S304 uses cement slurry with a water-cement ratio of cement to water of 0.7:1.0 to 1:1.0.

[0072] In specific settings, the method of using anchor mesh spraying support in S4 includes the following steps:

[0073] S401. Clear the rock section of pumice;

[0074] S402. Initial spraying of the roadway with plain concrete;

[0075] S403. Drill several rows of anchor holes perpendicular to the tunnel rock wall;

[0076] S404. Install resin anchors;

[0077] S405. Use steel bars for meshing;

[0078] S406. Install double reinforcement bars from one end of the same row of anchors to the other. The double reinforcement bars consist of two parallel steel bars, one on each side of the anchor, with a distance of 50 mm between them. The bars are fixed together with steel bars, and each bar is fixedly connected to the anchor support plate.

[0079] S407. Prestress the anchor rods and then spray concrete for the second time.

[0080] In specific settings, the thickness of the sprayed concrete in S402 is 40-60 mm, and the thickness of the secondary sprayed concrete in S407 is 90-110 mm.

[0081] The principles and advantages of this tunneling construction technology under the coal roof of the ventilation tunnel are as follows: by lowering the tunnel construction layer and leaving a construction platform at the head, the roof is effectively controlled, reducing the possibility of roof falling accidents during tunneling under the coal roof of the ventilation tunnel; by using small excavators for delivery, the tunneling construction efficiency is improved and the labor intensity of employees is reduced; by grouting shallow holes along the side wall, the surrounding rock is effectively reinforced, so that the maximum deformation along the side is less than 100mm; by following the bottom of the right side and planting short legs on the left side to break the bottom by 200mm, the efficiency of the head-on construction is improved, and after the rear road comprehensive excavator shovels the bottom, the left side is supported by anchor mesh spraying, and the tunnel section is effectively utilized without waste.

[0082] The above description is merely an embodiment of the present invention and is not intended to limit the scope of protection of the present invention. For those skilled in the art, the present invention may be subject to various modifications and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of protection of the present invention. It should be noted that similar reference numerals and letters represent similar items in the following figures. Therefore, once an item is defined in one figure, it does not need to be further defined or explained in subsequent figures.

[0083] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. The construction technology of tunneling under the coal roof of ventilation lane is characterized by: The following steps are involved: S1. Lower the tunnel construction level, changing the bottom break to 1.5m on the right side and 200mm on the left side. Manually locate the beam path, and lag the tunnel boring machine 10-15m behind to shovel the bottom. S2. Use small excavator to ship goods; S3. Grout shallow holes along the side walls of the empty space, and evenly arrange two 1m long grouting anchors in each shed for grouting reinforcement; S4. Construction is carried out on the right side following the coal bottom, and on the left side, the bottom is broken 200mm and short legs are planted. In the later stage, the rock section after the tunnel boring machine digs the bottom is supported by anchor net spraying.

2. The construction process for tunneling under the coal roof of the ventilation lane according to claim 1 is characterized in that: Before S1, it also includes: preparatory work and the advancement and arrangement of the power system and the ventilation system. The preparatory work includes equipment installation, personnel preparation and material preparation. The advancement and arrangement of the power system and the ventilation system are used as energy and safety guarantees during the rock tunnel excavation process. They need to be extended forward and arranged after the working face of each rock tunnel is advanced a certain distance.

3. The construction process for tunneling under the coal roof of the ventilation lane according to claim 2 is characterized in that: The ventilation system is used to ventilate and remove dust in the tunnel, and the dust removal work includes the following steps: S101. Air is forced into the duct. After combining with dust, the dust-laden air is drawn into the dust collector, silenced by the muffler section, filtered by the filter section, and then passes through the rear end of the dust collector. The air volume supplied to the duct is Q', and the dust-laden air volume extracted from the dust collector is Q. S102. The air control device changes the flow direction of the purified clean air, so that a portion of the clean air volume Q1 is pressed into the dust in the roadway, while another portion of the clean air volume Q2 is diffused toward the rear end of the dust collector. Based on the law of flow conservation, it can be obtained that during operation, Q = Q1 + Q2; S103. The air volume Q extracted by the dust collector is greater than Q', and the clean air volume Q1 pressed into the dust collector is equal to Q-Q'. At this time, a negative pressure effect is formed at the front end of the dust collector. At the same time, the wall attachment effect of the airflow is used to change the airflow of this part of the clean air volume Q1 into a rotating airflow along the tunnel wall, and blow it toward the tunnel wall and the entire tunnel section at a certain rotation speed, continuously advancing head-on to prevent the dust-laden airflow from spreading to the rear end of the dust collector.

4. The construction process for tunneling under the coal roof of the ventilation lane according to claim 3 is characterized in that: The air volume of Q1 in S103 is changed by adjusting the structural parameters of the wind control device, which includes a servo motor, fan blades and a control module. The control module is used to control the speed of the servo motor, and the servo motor is transmission-connected to the fan blades.

5. The construction process for tunneling under the coal roof of the ventilation lane according to claim 1 is characterized in that: The method for grouting anchor rods in S3 includes the following steps: S301 will be floating in the use of tunnel boring machine or blasting way out of the tunnel wall of the broken rock, coal cleaned up, with a jackhammer stripping the tunnel wall of the dangerous rock brush out of the rough section of the tunnel; S302. The inner wall of the roadway is sprayed with a shotcrete machine to obtain a concrete spray layer; S303. Use compressed air or water to remove rock dust from the grouting anchor hole. Add anchoring agent and insert the anchor rod to anchor the grouting anchor rod into the surrounding rock. Seal the hole with cement. S304. Use a grouting machine to inject grout into the surrounding rock through the grouting anchor rod. After the grouting is completed, seal and tighten the grouting anchor rod tray in a timely manner. S305. After grouting is completed, testing is carried out.

6. The construction process for tunneling under the coal roof of the ventilation lane according to claim 5 is characterized in that: In the above-mentioned S304, when the pump pressure in the surrounding rock reaches 1.4-3.2 MPa or grouting occurs in adjacent boreholes, grouting is stopped immediately. The grouting time for a single hole is 15-35 minutes.

7. The construction process for tunneling under the coal roof of the ventilation lane according to claim 6 is characterized in that: The grouting slurry in S304 is cement slurry with a water-cement ratio of cement to water of 0.7:1.0 to 1:1.

0.

8. The construction process for tunneling under the coal roof of the ventilation lane according to claim 1 is characterized in that: The method of using anchor mesh spraying support in S4 includes the following steps: S401. Clear the rock section of pumice; S402. Initial spraying of the roadway with plain concrete; S403. Drill several rows of anchor holes perpendicular to the tunnel rock wall; S404. Install resin anchors; S405. Use steel bars for meshing; S406. Install double reinforcement bars from one end of the same row of anchors to the other. The double reinforcement bars consist of two parallel steel bars, one on each side of the anchor, with a distance of 50 mm between them. The bars are fixed together with steel bars, and each bar is fixedly connected to the anchor support plate. S407. Prestress the anchor rods and then spray concrete for the second time.

9. The construction process for tunneling under the coal roof of the ventilation lane according to claim 8 is characterized in that: The thickness of the sprayed concrete in S402 is 40-60 mm, and the thickness of the secondary sprayed concrete in S407 is 90-110 mm.

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