CN107780955B - A controllable grouting reinforcement device and construction method for broken surrounding rock roadway - Google Patents

Abstract

The invention discloses a controllable grouting reinforcement device for breaking surrounding rock roadway and a construction method, wherein the reinforcement device comprises a grouting anchor rod, a fixed grouting stop plug, a movable grouting stop plug and an automatic extension type hole plugging device; the side walls of the middle part and the front part of the grouting anchor rod are provided with local grouting holes, and the surface of the grouting anchor rod is provided with threads; the outer surface of the partial grouting hole in the middle of the grouting anchor rod is provided with a fixed grouting stop, a movable grouting stop and an automatic extension type hole plugging device, the movable grouting stop is connected with the automatic extension type hole plugging device, and the movable grouting stop is arranged opposite to the fixed grouting stop; the automatic extension type hole plugging device can preset pressure, and can automatically extend along the axis of the anchor rod when grouting pressure reaches preset pressure. The grouting device can automatically adjust and control the grouting range according to the surrounding rock crushing condition, has good supporting effect on the crushed surrounding rock, has small grouting amount, can greatly reduce grouting cost, and ensures long-term stability of the crushed surrounding rock roadway.

Description

A controllable grouting reinforcement device and construction method for broken surrounding rock roadway

technical field

The invention belongs to the technical field of surrounding rock control of deformed roadways in coal mine roadway engineering, and in particular relates to a controllable grouting reinforcement device and a construction method for breaking surrounding rock roadways.

Background technique

In recent years, due to the gradual reduction of mineral resources in the shallow coal seams with better occurrence conditions, human beings must focus on the mining of coal seam minerals with more complex occurrence conditions. This type of coal seam mining often faces high geostress, large structural belts, and high gas. Extremely difficult comprehensive problems such as pressure. The excavation and maintenance of broken coal and rock roadways under complex conditions are generally poor in stability of surrounding rock, difficult to support, and safe gender issues. Anchor rods and anchor cables are a form of active support, but the anchored rock mass is some extremely broken or loose rock mass, and the anchorability of the surrounding rock is poor. It often shows that after the support, the surrounding rock and the bolt deform or slip together, and the support effect is not obvious. After a period of time after the support, it must be repaired, expanded, and bottomed to meet further production requirements. In addition, due to the broken surrounding rock, the anchor tray and nut anchored on the surrounding rock wall of the roadway will often fall into the broken rock mass after being stressed, causing the anchor to be twisted and the force is uneven. When the roadway is excavated in this kind of broken coal and rock mass, the bolt is abandoned as active support.

When encountering this kind of broken coal and rock mass roadway, the support method that is more considered in coal mines is mainly metal brackets as passive support. However, passive support methods such as metal brackets only rely on the strength of the support itself , it is difficult to withstand the effects of high ground stress and creep. After being disturbed by various stresses, such as "net pockets" and other very obvious deformation phenomena can be seen everywhere in the roadway, which is difficult to meet the support and production requirements. In order to seek a better support method, some coal mines have tried hollow full-length grouting bolts and metal brackets for such broken roadways, and the support effect has been improved, but from the perspective of economic benefits and support effects , using this support method, the grouting range cannot be controlled, and the amount of grouting is very large, and the construction cost and labor intensity will increase accordingly. In actual production, it is often not necessary to carry out full-length grouting support, that is, the support method of controlling the range of local staged grouting has a significant effect.

Contents of the invention

In order to solve the above-mentioned technical problems, the present invention provides a grouting range that can automatically adjust and control the grouting range according to the crushing situation of the surrounding rock. Controlled grouting reinforcement device and construction method, which can give full play to the active and passive support functions of grouting anchor rods and U-shaped steel brackets, achieve "internal and external" coupling to jointly support the broken surrounding rock, and ensure the supporting structure and broken surrounding rock long-term stability.

The technical solution of the present invention to solve the above technical problems is: a controllable grouting reinforcement device for crushing surrounding rock roadways, including grouting anchor rods, fixed grout stoppers, movable grout stoppers, automatic extension type Hole plugging device; the middle part of the grouting anchor and the front side wall are provided with local grouting holes, and the surface of the grouting anchor is provided with threads; the outer surface of the local grouting hole in the middle of the grouting anchor is provided with fixed Type grout stopper, movable grout stopper, automatic extension type plugging device, removable grout stopper is connected with automatic extension type plugging device, movable grout stopper and fixed grout stopper are set opposite to each other ; The automatic extension plugging device can preset pressure, and can automatically extend along the axis of the bolt when the grouting pressure reaches the preset pressure.

The above-mentioned controllable grouting reinforcement device for crushing the surrounding rock roadway also includes a U-shaped steel bracket, a tray, a nut and a grout plug at the end of the anchor rod, and the U-shaped steel bracket, tray, nut and the end of the anchor rod The grouting plug is set at the end of the grouting anchor rod, the tray is located between the U-shaped steel bracket and the nut, the grouting plug at the end of the anchor rod blocks the anchor hole at the end of the grouting anchor rod, and the nut closes to the end of the anchor rod. Plug settings.

In the above-mentioned controllable grouting reinforcement device for crushing surrounding rock roadways, the movable grout stopper includes a connecting sleeve and an elastic grout stopper; the elastic grout stopper is a hollow frustum-shaped structure, The small end is connected with the connecting sleeve; the inner hole of the connecting sleeve is provided with threads; the connecting sleeve of the removable grout stopper is screwed with the grouting anchor rod, and the elastic grout blocking device is arranged backward.

The above-mentioned controllable grouting reinforcement device for roadway with broken surrounding rocks also includes an anchor net, and the anchor net is placed between the U-shaped steel bracket and the surface of the roadway.

In the above-mentioned controllable grouting reinforcement device for crushing surrounding rock roadways, the automatic extension plugging device includes an outer cylinder, an inner cylinder and an inner cylinder placed in the outer cylinder, the inner cylinder and the outer cylinder are coaxial, and the inner cylinder and the outer cylinder are coaxial. The outer wall of the cylinder and the inner wall of the outer cylinder are provided with a buckle device; the inner thread at the rear end of the outer cylinder is connected with the outer thread of the movable stopper connecting sleeve.

In the above-mentioned controllable grouting reinforcement device for crushing surrounding rock roadways, the front end of the outer cylinder is provided with a stop plate I, and the rear end of the inner cylinder is provided with a stop plate II, and the diameter of the inner hole of the stop plate I is greater than the outer diameter of the inner cylinder; the outer diameter of the stop plate II is greater than the diameter of the inner hole of the stop plate I, and smaller than the inner diameter of the outer cylinder; the inner wall of the inner cylinder is provided with a slurry plug.

A controllable grouting construction method for crushing surrounding rock roadways using the above-mentioned controllable grouting reinforcement device for crushing surrounding rock roadways, comprising the following steps:

(1) Spread the anchor net on the surface of the newly excavated roadway, set up the U-shaped rigid bracket, and install and fix the frame legs and top beams on the surface of the roadway through U-shaped steel clamping cables;

(2) Determine the number of grouting anchors needed, and then use the anchor drill to drill the anchor holes through the anchor installation holes left on the erected U-shaped steel bracket;

(3) Install a removable grout stopper in front of the local grout hole of the hollow anchor, and install a fixed grout stopper behind the partial grout hole of the hollow anchor rod. The movable grout stopper and the fixed grout stopper The grout plugs are installed relative to each other, and the distance between them is the thickness of the load-bearing arch; and according to the brokenness of the surrounding rock of the supported roadway, the thickness of the grouted load-bearing arch is automatically adjusted and controlled;

(4) Anchor the anchoring agent and the grouting bolt with the removable grout stopper installed in the bolt hole, and then install the tray and nut;

(5) Connect the grouting pump to the end of the grouting anchor rod for grouting. After the expected grouting pressure is reached, stop the grouting, and install a grouting plug at the end of the anchor rod to complete the supporting work.

In the above-mentioned controllable grouting construction method for breaking the surrounding rock roadway, the specific method of adjusting and controlling the thickness of the grouting bearing arch in step (3) is as follows:

Preset the minimum thickness of the first layer of grouting bearing arch; if the surrounding rock is relatively stable, control the grouting pressure to reach the preset pressure of the reverse buckle device of the automatic extension type hole plugging device, and the inner part of the automatic extension type hole plugging device The cylinder extends to block the grouting hole in front of it, and the grouting range is controlled. When the control range is reached, the grouting pressure is reduced to make it less than the preset pressure of the reverse buckle device, and the reverse buckle device buckles the inner cylinder;

If the surrounding rock is relatively broken, the applied grouting pressure is too small to reach the preset pressure of the anti-buckle device of the automatic extension type hole plugging device, and the inner cylinder of the automatic extension type hole plugging device will not protrude out of the plugging hole , The grouting holes in front and behind of the movable grout stopper and the automatic extension plugging device will be grouted at the same time, and the surrounding rock will be broken to form a double-layer grouting bearing arch to strengthen the supporting effect.

Compared with prior art, the beneficial effect of the present invention is:

1. The controllable grouting reinforcement device for broken surrounding rock roadway of the present invention has local grouting holes in the front and middle of the grouting bolt, which is a local segmental grouting structure, and the hole is automatically extended to block the holes The device can automatically adjust and control the grouting range according to the different degrees of crushing of the surrounding rock, and can form stress-bearing arches with different thicknesses in the crushed surrounding rock.

2. The controllable grouting reinforcement device for the broken surrounding rock roadway of the present invention uses the grouted anchor rod, U-shaped steel bracket and anchor net to jointly support the broken surrounding rock in the broken roadway, and the grouted anchor rod after grouting It is divided into two sections. The first section is the load-bearing arch and the coupling part between the load-bearing arch and the anchoring end of the grouted anchor, which can control the rock formation in front of it; while the coupling support of the anchor and U-shaped steel bracket behind the load-bearing arch is the second section, which can control The broken rock formation behind the load-bearing arch is coordinated between the two sections to realize the coupling of active support and passive support, which forms a support system of "inner and outer load-bearing structures" around the roadway of the broken coal and rock mass.

3. The controllable grouting reinforcement device for the broken surrounding rock roadway of the present invention not only realizes the support function of the full-length grouting bolt by using the movable grouting stopper, but also can greatly reduce the amount of grouting, and The support effect is obviously improved, the construction time of workers is effectively reduced, and the economic benefits are remarkable.

4. The controllable grouting reinforcement device for broken surrounding rock roadway of the present invention, the end tray and nut of the grouting anchor rod are installed on the surface of the U-shaped steel bracket, the force on the anchor rod is uniform, and the distortion and deformation of the anchor rod are reduced Probability, the tray and the nut will not sink into the surface of the broken surrounding rock, which ensures the supporting effect of the bolt and improves the stability of the supporting structure.

Description of drawings

Fig. 1 is a schematic diagram of the structure of the surrounding rock broken by the controllable grouting reinforcement device of the present invention.

Fig. 2 is a connection structure diagram of the U-shaped steel bracket and the fixed end of the grouting anchor rod according to the present invention.

Fig. 3 is a structural schematic diagram of the grouting anchor rod of the present invention.

Fig. 4 is a structural diagram of the movable grout stopper of the present invention.

Fig. 5 is a schematic diagram of the automatic extension structure of the automatic extension type hole plugging device of the present invention.

Among them: 1-U-shaped steel bracket, 2-U-shaped steel clamp cable, 3-anchor net, 4-grouting anchor rod, 5, fixed grout stopper, 6-removable grout stopper, 7-automatic extension Plugging device, 8-tray, 9-nut, 10-bolt plug at the end of the anchor rod, 11-grouting system, 12-bolt installation hole, 13-partial grouting hole, 14-bolt thread, 61- Elastic shrinkable pulp blocking device, 62-connecting sleeve, 71-outer cylinder, 72-inner cylinder, 73-reversing device, 74-stop device, 75-slurry plug, 76-internal thread.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings.

As shown in Figures 1-3, the controllable grouting reinforcement device for crushing surrounding rock roadways of the present invention includes a U-shaped steel bracket 1, an anchor net 3, a grouting anchor rod 4, a fixed grout stopper 5, a movable Grout stopper 6, automatic extension plugging device 7, tray 8, nut 9, grout stopper 10 at the end of the anchor rod and grouting system 11. The anchor net 3 is arranged on the roadway surface, between the U-shaped steel support 1 and the roadway surface. The U-shaped steel bracket 1 has anchor rod installation holes 12 at the joints of the frame legs, the top beam joints and between the frames, through which the anchor rod installation holes are sleeved on the tail end of the grouting anchor rod 4, and the rear part is provided with a tray in turn 8 and nut 9 are fixed by nut 9. A grouting plug 10 at the end of the grouting anchor 4 is provided at the anchor hole at the end of the grouting anchor 4 to prevent the mortar from flowing back from the grouting anchor 4 after the grouting is completed. The middle part and the front part of the grouting anchor 4 are provided with local grouting holes 13, and the surface of the grouting anchor 4 has threads 14. The local grouting hole 13 in the middle of the grouting anchor rod 4 is equipped with a fixed grout stopper 5, a movable grout stopper 6 and an automatic elongation plugging device 7, a fixed grout stopper 5, a movable grout stopper The grout stopper 6 is arranged oppositely, the movable grout stopper 6 is located in front of the fixed grout stopper 5, and the front end of the movable grout stopper 6 is connected to the rear end of the automatic extension type plugging device 7 .

As shown in Figures 3-4, the removable grout stopper 6 includes an elastic grout stopper 61 and a connecting sleeve 62. The elastic grout stopper 61 is a hollow frustum-shaped structure, and its small end is connected to the One end of the sleeve 62 is connected, and the side wall of the inner hole of the connecting sleeve 62 and the outer cylindrical surface are all provided with threads, and the threads on the side wall of the inner hole are screwed with the grouting anchor rod 4, and can be screwed on the body of the grouting anchor rod 4. The surface moves back and forth by means of threads 14 . The screw thread on the outer cylindrical surface of the connecting sleeve 62 is connected with the automatic extension type plugging device 7 .

As shown in Figure 5, the automatic extension type plugging device comprises an outer cylinder 71, an inner cylinder 72, the inner cylinder 72 is placed in the outer cylinder 71, and is coaxial with the outer cylinder 71, the outer wall of the inner cylinder 72 and the outer cylinder 71 The inner wall of the inner cylinder is provided with a reverse buckle device 73; the reverse buckle device 73 can preset the pressure, and when the pressure reaches the preset pressure, the inner cylinder 72 will be released and stretched out to block the grouting of the upper part of the grouting anchor rod 4. Hole 13 controls the grouting range. The rear end of the outer cylinder is provided with an internal thread 76 , and the internal thread 74 is a fine thread, which is used for threaded connection with the outer cylindrical surface of the movable stopper connecting sleeve 62 . The front end of the outer cylinder 71 of the automatic extension type plugging device 7 is provided with a stop plate I 711, and the rear end of the inner cylinder 72 is provided with a stop plate II 721, and the diameter of the inner hole of the stop plate I 711 is greater than the outer diameter of the inner cylinder; The outer diameter of the plate II 721 is greater than the diameter of the inner hole of the stop plate I 711, and is smaller than the inner diameter of the outer cylinder 71. A slurry plug 75 is provided on the inner wall of the inner cylinder 72 .

The controllable grouting construction method for crushing surrounding rock roadways of the present invention comprises the following steps:

(1) Spread the anchor net 3 on the surface of the newly excavated roadway, set up the U-shaped rigid support 1, and install and fix the frame legs and top beams through the U-shaped steel clamping cable 2;

(2) Determine the number of grouting anchors 4 needed, and then use the anchor drill to drill anchor holes through the anchor installation holes 12 left on the erected U-shaped steel bracket 1;

(3) Install a removable grout stopper 6 at the front of the partial grouting hole 13 of the grouting anchor 4, and install a fixed grout stopper 5 behind the partial grouting hole 13 of the staged hollow anchor 4, The movable grout stopper 6 is installed opposite to the fixed grout stopper 5, and the distance between the two is the thickness of the load-bearing arch; according to the brokenness of the surrounding rock of the supported roadway, the thickness of the grouting load-bearing arch is automatically adjusted and controlled. The adjustment method as follows:

Preset the minimum thickness of the first grouting bearing arch (that is, the minimum distance between the movable grout stopper 6 and the fixed grout stopper 5). If the surrounding rock is relatively stable, control the grouting pressure to reach the preset pressure of the buckle device 73 of the automatic extension type hole plugging device 7, and the inner cylinder 72 of the automatic extension type hole plugging device 7 will stretch out and block its front The grouting hole 13 is used to control the grouting range. When the control range is reached, the grouting pressure is reduced to make it less than the preset pressure of the reverse buckle device. The reverse buckle device 73 buckles the inner cylinder 72, and the grouting forms a single The layers of grouting bear the arch.

If the surrounding rock is relatively broken, and the control grouting pressure cannot reach the preset pressure of the automatic extension type hole plugging device 7 reverse buckle device 73, the inner cylinder 72 of the automatic extension type hole plugging device 7 will not protrude, and the movable type The grout stopper 6 and the grouting hole 13 at the front and rear of the automatic extension plugging device 7 will be grouted at the same time, and the broken surrounding rock will form a double-layer grouting bearing arch to strengthen the supporting effect;

(4) Anchor the anchoring agent and the grouting bolt 4 with the removable grout stopper 6 installed in the bolt hole, and then install the tray 8 and the nut 9;

(5) Connect the grouting pump to the grouting anchor rod 4 for grouting. After the expected grouting pressure is reached, stop the grouting, and install a grouting plug 10 at the end of the anchor rod to complete the supporting work.

Claims (6)

1. A controllable grouting reinforcement device for breaking surrounding rock roadway comprises a grouting anchor rod, a fixed grouting stop plug, a movable grouting stop plug and an automatic extension type hole plugging device; the side walls of the middle part and the front part of the grouting anchor rod are provided with local grouting holes, and the surface of the grouting anchor rod is provided with threads; the outer surface of the partial grouting hole in the middle of the grouting anchor rod is provided with a fixed grouting stop, a movable grouting stop and an automatic extension type hole plugging device, the movable grouting stop is connected with the automatic extension type hole plugging device, and the movable grouting stop is arranged opposite to the fixed grouting stop; the automatic extension type hole plugging device can preset pressure, and can automatically extend along the axis of the anchor rod when the grouting pressure reaches the preset pressure; the grouting device comprises a grouting anchor rod, and is characterized by further comprising a U-shaped steel bracket, a tray, a nut and an anchor rod end blocking plug, wherein the U-shaped steel bracket, the tray, the nut and the anchor rod end blocking plug are arranged at the tail end of the grouting anchor rod; the movable slurry stop plug comprises a connecting sleeve and an elastic slurry stop device; the elastic slurry blocking device is of a hollow frustum-shaped structure, and the small end of the elastic slurry blocking device is connected with the connecting sleeve; threads are arranged in the inner hole of the connecting sleeve; the connecting sleeve of the movable grouting stop is in threaded connection with the grouting anchor rod, and the elastic grouting blocking device is arranged backwards.

2. The controllable grouting reinforcement device for breaking surrounding rock roadway according to claim 1, wherein: the anchor net is arranged between the U-shaped steel bracket and the surface of the roadway.

3. The controllable grouting reinforcement device for breaking surrounding rock roadway according to claim 1, wherein: the automatic extension type hole plugging device comprises an outer cylinder and an inner cylinder, wherein the inner cylinder is arranged in the outer cylinder, the inner cylinder is coaxial with the outer cylinder, and the outer side wall of the inner cylinder and the inner side wall of the outer cylinder are provided with anti-buckling devices; the inner thread at the rear end of the outer cylinder is connected with the thread on the outer cylindrical surface of the movable slurry stop plug connecting sleeve.

4. A controllable grouting reinforcement device for broken surrounding rock roadway according to claim 3, characterized in that: the front end of the outer cylinder is provided with a stop plate I, the rear end of the inner cylinder is provided with a stop plate II, and the diameter of an inner hole of the stop plate I is larger than the outer diameter of the inner cylinder; the outer diameter of the stop plate II is larger than the diameter of the inner hole of the stop plate I and smaller than the inner diameter of the outer cylinder; the inner wall of the inner cylinder is provided with a slurry blocking soft plug.

5. A controllable grouting construction method for breaking a surrounding rock roadway using the controllable grouting reinforcement device for breaking a surrounding rock roadway according to any one of claims 1 to 4, comprising the steps of: (1) Paving an anchor net on the surface of a newly tunneled roadway, erecting a U-shaped rigid support, and installing and fixing a support leg and a top beam on the surface of the roadway through a U-shaped steel clamping cable; (2) Determining the number of needed grouting anchor rods, and then punching anchor rod holes by using an anchor rod drilling machine through anchor rod mounting holes reserved on the erected U-shaped steel bracket; (3) A movable grout stop plug is arranged in front of a partial grout hole of a hollow anchor rod, a fixed grout stop plug is arranged behind the partial grout hole of the hollow anchor rod, the movable grout stop plug and the fixed grout stop plug are arranged oppositely, and the distance between the movable grout stop plug and the fixed grout stop plug is the thickness of a bearing arch; according to the surrounding rock crushing condition of the supported roadway, the grouting bearing arch thickness is automatically adjusted and controlled; (4) Anchoring the anchoring agent and the grouting anchor rod provided with the movable grouting plug into the anchor rod hole, and then installing a tray and a nut; (5) And (3) connecting the grouting pump with the tail end of the grouting anchor rod for grouting, stopping grouting after the expected grouting pressure is reached, and installing a grouting plug at the end part of the anchor rod to complete the supporting work.

6. The controllable grouting construction method for breaking surrounding rock roadway according to claim 5, wherein the concrete method for adjusting and controlling the thickness of the grouting bearing arch in the step (3) comprises the following steps: firstly, presetting the minimum thickness of a first layer grouting bearing arch; if the surrounding rock is stable, controlling the grouting pressure to reach the preset pressure of a back-buckling device of the automatic extension type hole plugging device, extending an inner cylinder of the automatic extension type hole plugging device to plug a grouting hole in front of the automatic extension type hole plugging device, controlling the grouting range, and reducing the grouting pressure to be smaller than the preset pressure of the back-buckling device when the grouting range is reached, wherein the back-buckling device buckles the inner cylinder; if surrounding rock is broken, grouting pressure is controlled to be less than the preset pressure of the back-buckling device of the automatic extension type hole plugging device, an inner cylinder of the automatic extension type hole plugging device cannot extend out of a hole, grouting holes in front of and behind the movable grouting plug and the automatic extension type hole plugging device can be used for grouting simultaneously, broken surrounding rock forms a double-layer grouting bearing arch, and supporting effect is enhanced.

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