A method for multi-layer multi-angle goaf grouting filling

Abstract

The application discloses a kind of multilayer position-multiangle old goaf grouting filling method.The method comprises the following steps of: firstly, finding out the distribution characteristics of old goaf and residual coal pillar;Then drill into the old goaf to the basic roof rock layer and stop drilling, put the casing with inclined elbow, put the high-pressure hose with self-feeding drill bit in the casing, remove the self-feeding drill bit after reaching the old goaf, inject filling slurry along the pipeline, change the direction of the casing, repeat the self-drilling and grouting process, and repeat the drilling process to treat the lower goaf after the upper goaf is treated.The application solves the problem of small grouting filling range and poor filling effect in the old goaf, and realizes multilayer and multi-angle grouting through one drilling, which greatly reduces the grouting cost while ensuring the grouting effect.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of filling and grouting, and particularly relates to a method for multi-layer and multi-angle grouting filling of old goaf. BACKGROUND

[0002] With the rapid development of urban and engineering construction in China, the construction land is increasingly tight, especially in resource-based cities, and some civil buildings, industrial structures and traffic facilities are forced to be built or pass through the goaf (mining) area. In recent years, some cities have begun to build various large buildings on the goaf or the area to be mined in order to solve the bottleneck of construction land and intensively use land.

[0003] The first thing for development and construction on the goaf is the treatment and construction of the goaf. China is vast in territory, and the occurrence of coal seams is quite different. Many goafs are formed after multi-seam mining. At present, the most commonly used method is goaf grouting reinforcement technology, that is, drilling a hole from the ground to the goaf, and then injecting prepared slurry into the goaf after drilling to the predetermined position.

[0004] Patent document (publication number CN101021162) discloses a covering rock separation grouting filling device and grouting filling system, which can solve the problems of few grouting layers, discontinuous grouting and low grouting efficiency of the existing covering rock separation grouting filling technology. However, special casing needs to be made in advance according to special stratum conditions, the operation steps are complicated, and the applicability and practicality are insufficient. Patent document (publication number CN103216236A) discloses a method for reducing subsidence by grouting into the covering rock separation of the mining area, which has certain benefits for controlling ground subsidence. However, this method is only suitable for the coal seam being mined and is not suitable for the treatment of old goaf. Patent document (publication number CN105804752A) discloses a monitoring process for covering rock separation grouting in coal strip mining. The invention solves the problems of difficult grouting in multi-layer goaf and difficulty in finding the separation of overburden rock. However, the invention needs to repeatedly drill holes, the grouting range is small, and the grouting process is complicated.

[0005] In addition, most of the current grouting filling is single drilling from the ground to the goaf, reaching the predetermined position, and then starting grouting. Since the amount of slurry borne by each drill hole is limited, the filling range is small. In order to improve the filling effect, many intensive drill holes need to be drilled, which greatly increases the cost of grouting.

[0006] In summary, it is urgent to find a filling method that can realize one-time drilling, multi-layer and multi-directional comprehensive grouting into the old goaf. SUMMARY

[0007] The application provides a filling method for realizing comprehensive grouting of multiple layers and multiple angles through one-time drilling of an old goaf.

[0008] To achieve the above object, the application is implemented by the following technical scheme:

[0009] A method for grouting and filling of an old goaf with multiple layers and multiple angles, comprising the following steps:

[0010] Step 1: detecting the old goaf to find out the distribution characteristics of the old goaf and the residual coal pillars;

[0011] Step 2: drilling a hole from the ground above the old goaf towards the old goaf, and drilling the hole to the vicinity of the basic roof of the upper goaf;

[0012] Step 3: lowering a casing pipe with an inclined elbow in the hole, lowering a high-pressure hose in the casing pipe, connecting the bottom of the high-pressure hose with a self-advancing drill bit, using the forward jet of the self-advancing drill bit to break rocks and provide a channel for the drill bit to advance, using the reverse jet of the self-advancing drill bit to generate a forward thrust, and using the internal impeller to increase the pressure to help the forward jet to break rocks;

[0013] Step 4: making the self-advancing drill bit drill into the upper goaf along the direction of the casing pipe elbow, stopping drilling until the self-advancing drill bit is drilled into the upper goaf, removing the self-advancing drill bit, and starting grouting and filling, and stopping grouting and filling when the filling material starts to backflow from the high-pressure hose;

[0014] Step 5: removing the high-pressure hose, changing the direction of the casing pipe, then lowering the high-pressure hose connected with the self-advancing drill bit in the casing pipe, repeating step 4 until the grouting and filling of the upper goaf is completed;

[0015] Step 6: continuing to drill downwards along the direction of the hole in step 2, drilling the hole to the vicinity of the basic roof of the lower goaf, and repeating steps 3 to 5 to complete the grouting and filling of the lower goaf.

[0016] Preferably, the high-density electrical method, the three-dimensional laser scanner or the method for determining the range of the old goaf described in the Chinese patent document with the authorization announcement number CN104965229A is used to detect the old goaf in step 1.

[0017] Preferably, the hole diameter of the hole drilled in step 2 is Φ130mm.

[0018] Preferably, the hole position deviation of the hole drilled in step 2 is less than 1m, and the hole inclination is less than 1°.

[0019] Preferably, the hole drilled in step 2 is drilled to a position 2-5m away from the basic roof of the upper goaf.

[0020] As preferred, the aperture of the sleeve pipe in step 3 is Φ90mm, and the pipe wall thickness is 8mm.

[0021] As preferred, the inclination angle of the inclined elbow in step 3 is -51°.

[0022] As preferred, the aperture of the high-pressure hose in step 3 is Φ50mm, and the pipe wall thickness is 4mm.

[0023] As preferred, the filling slurry in step 4 is a mixture slurry of cement and fly ash, and the weight ratio of cement to fly ash is 4:6.

[0024] As preferred, the drilling hole in step 6 is drilled to a distance of 2-5m from the underlying goaf basic roof.

[0025] Compared with the prior art, the present application has the following beneficial effects

[0026] The present application can realize comprehensive grouting of multiple layers and multiple angles through one-time drilling, and can solve the shortcomings of repeated drilling, successive grouting, small grouting and filling range and poor filling effect of the current old goaf, while ensuring the grouting effect, greatly reducing the grouting cost and improving the management efficiency of the old goaf. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 It is a multi-angle grouting flowchart for the upper goaf;

[0028] Figure 2 It is a multi-angle grouting flowchart for the underlying goaf;

[0029] Figure 3 It is a goaf grouting effect plan view;

[0030] Figure 4 It is a self-feeding drill bit structure schematic diagram;

[0031] Figure 5 It is an enlarged schematic diagram of the elbow hole;

[0032] Figure 6 It is a high-pressure pump house internal structure diagram;

[0033] In the figure, 1 is a pool, 2 is a high-pressure connecting hose, 3 is a high-pressure pump station (3.1 is a high-pressure pump, 3.2 is a flow meter, 3.3 is a pressure meter), 4 is a first valve, 5 is a second valve, 6 is a slurry mixing pool, 7 is a drilling hole, 8 is a sleeve pipe, 9 is a high-pressure hose, 10 is an inclined sleeve elbow, 11 is a self-feeding drill bit (11.1 is a rear nozzle, 11.2 is a front nozzle, 11.3 is an impeller), and 12 is a goaf. DETAILED DESCRIPTION

[0034] The following examples are intended to illustrate and explain the present application and do not limit the scope of the present application.

[0035] In order to have a clearer understanding of the technical objects, features and effects of the present application, the present application will be further described in detail with reference to the accompanying drawings.

[0036] The present application provides a multi-layer multi-angle old goaf grouting filling method, which comprises the following steps:

[0037] As shown in Figures 1 to 6 The present application provides a multi-layer multi-angle old goaf grouting filling method, which comprises the following steps:

[0038] Step 1: combining the original geological technical data of the mine, the distribution of the old goaf 12 in the proposed construction area is investigated and found out, and a shape distribution map of the old goaf and the coal pillar group is drawn;

[0039] Step 2: drilling a hole 7 from the ground to the old goaf, the hole 7 penetrates through the loose layer and drills into the complete bedrock section 5m, then the casing is lowered, and the cement mortar is used to solidify the pipe wall, after the hole mouth pipe is consolidated, the water pressure test is carried out, the maximum pressure is not less than 3MPa, which ensures that there is no slurry channeling, the final hole of the hole 7 is in the basic roof 2-5m of the upper goaf; the hole diameter of the hole 7 is Φ130mm, the hole deviation is less than 1m, and the hole inclination is less than 1°;

[0040] Step 3: lowering the casing 8 in the hole 7, the casing 8 is connected with the inclined casing elbow 10 at the bottom, the high-pressure hose 9 is placed in the casing 8, the head of the high-pressure hose 9 is connected with the self-advancing drill bit 11, and the tail is connected with the high-pressure pump station 3; the hole diameter of the casing 8 is Φ90mm, the pipe wall thickness is 8mm, the inclination angle of the inclined casing elbow 10 is-51°, the hole diameter of the high-pressure hose 9 is Φ50mm, and the pipe wall thickness is 4mm;

[0041] Step 4: start the first valve 4, close the second valve 5, start the high-pressure pump 3.1 in the high-pressure pump station 3, pump the water in the water tank 1 to the self-advancing drill bit 11 through the high-pressure connecting hose 2, the high-pressure water drives the impeller 11.3 to rotate to form a horizontal torrent, the rock in front of the drill bit is broken from the front nozzle 11.2, and the self-advancing drill bit 11 and the high-pressure hose 9 are sprayed backward from the rear nozzle 11.1 to drill into the goaf 12; adjust the water pressure according to the flow meter 3.2 and the pressure gauge 3.3, so that the water pressure is stable at about 3MPa, and the self-advancing drill bit 11 continuously advances forward;

[0042] Step 5: when it is found that the self-advancing drill bit 11 drills faster, whether the self-advancing drill bit 11 drills into the goaf 12 according to the shape of the goaf and the drilling distance is tested;

[0043] Step 6: after confirming that the self-advancing drill bit 11 drills into the goaf 12, close the high-pressure pump 3.1, close the first valve 4, take down the self-advancing drill bit 11, open the second valve 5, and send the filling slurry prepared in advance from the high-pressure hose 9 into the goaf 12 at a certain angle through the high-pressure pump station 3, the filling slurry is a mixture of cement and fly ash, and the weight ratio of cement to fly ash is 4:6; when the filling slurry injection is obviously slow and there is backflow from the high-pressure hose 9, stop grouting and filling;

[0044] Step 7: take out the high-pressure hose 9, adjust the angle of the casing 8, then lower the high-pressure hose 9 connected with the self-advancing drill bit 11 in the casing 8, repeat the operation process of steps 4 to 6, until the grouting and filling of the upper goaf is completed;

[0045] Step 8: continue to drill downward along the direction of the borehole 7 in step 2, drill the borehole 7 to the lower goaf basic roof 2-5m, repeat the operation process of steps 3 to 7, and complete the grouting and filling of the lower goaf.

[0046] The above describes the preferred embodiment of the present application, it should be noted that any improvement and modification of the above described implementation method without departing from the technical essence and principle of the present application, all belong to the protection scope of the technical scheme of the present application.

Claims

1. A method for grouting and filling old goaf areas at multiple locations and angles, characterized in that: Includes the following steps: Step 1: Explore the old goaf area to understand the distribution characteristics of the old goaf area and the remaining coal pillars; Step 2: Drill holes from the ground above the old goaf towards the old goaf, with the drilling ending near the top of the upper goaf. Step 3: Lower the casing with the inclined elbow into the borehole. The inclined elbow contacts the bottom wall of the borehole. Lower the high-pressure hose into the casing. The bottom of the high-pressure hose is connected to the self-feeding drill bit. Step 4: Drill the self-propelled drill bit along the direction of the casing bend into the upper goaf area until it reaches the upper goaf area. Stop drilling, remove the self-propelled drill bit, and start grouting. Stop grouting when the grouting material starts to backflow from the high-pressure hose. Step 5: Remove the high-pressure hose, change the direction of the casing, and then lower the high-pressure hose connected to the self-advancing drill bit into the casing. Repeat Step 4 until the grouting and filling of the upper goaf area is completed. Step 6: Continue drilling downwards along the drilling direction of Step 2 until the borehole reaches near the top of the lower goaf. Repeat Steps 3 to 5 to complete the grouting and filling of the lower goaf.

2. The method for grouting and filling multi-level, multi-angle old goaf areas according to claim 1, characterized in that: In step 1, a high-density electrical resistivity tomography (EDT) or a three-dimensional laser scanner is used to detect the old goaf.

3. The method for grouting and filling multi-level, multi-angle old goaf areas according to claim 1, characterized in that: The diameter of the hole drilled in step 2 is Φ130mm.

4. The method for grouting and filling multi-level, multi-angle old goaf areas according to claim 1, characterized in that: In step 2, the hole position deviation is less than 1m and the hole inclination is less than 1°.

5. The method for grouting and filling multi-level, multi-angle old goaf areas according to claim 1, characterized in that: In step 2, the drilling ends at a point 2-5m from the top of the upper goaf.

6. The method for grouting and filling multi-level, multi-angle old goaf areas according to claim 1, characterized in that: In step 3, the diameter of the sleeve is Φ90mm and the wall thickness is 8mm.

7. The method for grouting and filling multi-level, multi-angle old goaf areas according to claim 1, characterized in that: The tilt angle of the inclined bend in step 3 is -51°.

8. The method for grouting and filling multi-level, multi-angle old goaf areas according to claim 1, characterized in that: In step 3, the high-pressure hose has a diameter of Φ50mm and a wall thickness of 4mm.

9. The method for grouting and filling multi-level, multi-angle old goaf areas according to claim 1, characterized in that: In step 4, the filling slurry is a mixture of cement and fly ash, with a weight ratio of cement to fly ash of 4:

6.

10. A method for grouting and filling multi-level, multi-angle old goaf areas according to claim 1, characterized in that: In step 6, the drilling ends at a point 2-5m from the top of the lower goaf.

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