Full water goaf grouting method

Abstract

The present invention relates to the technical field of gob area treatment, and provides a grouting method for a fully water-filled gob area. The grouting method includes: arranging injection holes in the treatment area above the fully water-filled gob area, and filling aggregate into the fully water-filled gob area through the injection holes; injecting slurry into the fully water-filled gob area in sequence from the injection holes in the middle to the injection holes on the outside. The grouting method for the fully water-filled gob area provided by the embodiments of the present invention fills the aggregate into the fully water-filled gob area through multiple injection holes, and then injects the slurry into the fully water-filled gob area in sequence from the injection holes in the middle to the injection holes on the outside, so as to realize the filling of the gob area, and further avoid the dangerous problems brought by ground collapse.

Description

Technical Field

[0001] The present invention relates to the technical field of goaf treatment, and particularly to a grouting method for a fully - water - filled goaf. Background Art

[0002] The cavity area left after underground minerals are mined out and the surrounding rock mass deformation and instability thereof, which result in displacement, cracking, fragmentation and caving, and finally the surface deformation and damage caused by the overall bending and subsidence of the overlying rock and soil layers, are collectively referred to as goaf. The research on goaf treatment is mainly carried out in the coal system, and the main research purpose is to control ground settlement to protect the safety of ground buildings, industrial structures, etc.

[0003] A goaf is a cavity, cavity or roadway left underground after mining. If the goaf is not filled, it will cause ground collapse, thus bringing danger. Summary of the Invention

[0004] The present invention provides a grouting method for a fully - water - filled goaf to solve the defect of danger caused by ground collapse in the prior art.

[0005] The present invention provides a grouting method for a fully - water - filled goaf, including:

[0006] Arranging a plurality of injection holes in the treatment area above the fully - water - filled goaf, and filling the aggregate into the fully - water - filled goaf through the injection holes; wherein, the injection holes are multiple;

[0007] Injecting the slurry into the fully - water - filled goaf in sequence from the injection hole in the middle to the injection holes on the outside.

[0008] According to a grouting method for a fully - water - filled goaf provided by an embodiment of the present invention, the aggregate includes a first aggregate and a second aggregate, the particle size of the first aggregate is larger than that of the second aggregate, and filling the aggregate into the fully - water - filled goaf through the injection holes includes:

[0009] Injecting water and the first aggregate into the fully - water - filled goaf in sequence from the injection hole in the middle to the injection holes on the outside;

[0010] Injecting water and the second aggregate into the fully - water - filled goaf in sequence from the injection hole in the middle to the injection holes on the outside.

[0011] According to a grouting method for a fully - water - filled goaf provided by an embodiment of the present invention, before injecting water and the first aggregate into the fully - water - filled goaf in sequence from the injection hole in the middle to the injection holes on the outside, it further includes:

[0012] Determining the weight of the first aggregate injected into the fully - water - filled goaf by each injection hole based on formula (1);

[0013] m1 = ρ1f1πr 2 h (1)

[0014] Wherein, m1 represents the weight of the first aggregate; r represents the diffusion radius of the slurry; h represents the height of the fully - water - filled goaf; f1 represents the filling coefficient of the first aggregate; ρ1 represents the bulk density of the first aggregate.

[0015] According to a grouting method for a fully - water - filled goaf provided by an embodiment of the present invention, before injecting water and the second aggregate into the fully - water - filled goaf in sequence from the injection hole in the middle to the injection holes on the outside, it further includes:

[0016] Determining the weight of the second aggregate filled into the fully - water - filled goaf by each injection hole based on formula (2);

[0017] m2 = πr 2 h f1k f2ρ2 (2)

[0018] Wherein, m2 represents the weight of the second aggregate; r represents the diffusion radius of the slurry; h represents the height of the fully - water - filled goaf; f1 represents the filling coefficient of the first aggregate; k represents the porosity of the pile body of the first aggregate; f2 represents the filling coefficient of the second aggregate; ρ2 represents the bulk density of the second aggregate.

[0019] According to a grouting method for a fully - water - filled goaf provided by an embodiment of the present invention, injecting the slurry into the fully - water - filled goaf in sequence from the injection hole in the middle to the injection holes on the outside includes:

[0020] Arranging the grouting pipeline in the injection hole in the middle, and the grouting pipeline extends into the fully - water - filled goaf;

[0021] Injecting the slurry into the middle of the fully - water - filled goaf through the grouting pipeline;

[0022] Moving the grouting pipeline from the injection hole in the middle to the injection holes on the outside, and injecting the slurry into the outer area of the middle of the fully - water - filled goaf through the grouting pipeline.

[0023] According to a grouting method for a fully - water - filled goaf provided by an embodiment of the present invention, there is a vertical distance between the lower end surface of the grouting pipeline and the bottom plate of the fully - water - filled goaf, and the vertical distance is 1 / 5 - 2 / 5 of the height of the fully - water - filled goaf.

[0024] According to a grouting method for a fully - water - filled goaf provided by an embodiment of the present invention, the aggregate includes at least one of slag, sand, and crushed stone, and / or,

[0025] The slurry includes cement, fly ash, and loess, and the concentration of the slurry is 50% - 60%.

[0026] A grouting method for a fully - water - filled goaf according to an embodiment of the present invention, multiple circles of the injection holes on the outer side are arranged centered on the injection hole in the middle.

[0027] A grouting method for a fully - water - filled goaf according to an embodiment of the present invention, the slurry is sequentially injected into the fully - water - filled goaf from the injection hole in the middle to the injection holes on the outer side, and the grouting pressure is 1.0 Mpa to 3.0 Mpa.

[0028] A grouting method for a fully - water - filled goaf according to an embodiment of the present invention, the distance between two adjacent injection holes is 20 m to 40 m.

[0029] The grouting method for a fully - water - filled goaf provided by the embodiment of the present invention fills the aggregate into the fully - water - filled goaf through multiple injection holes, and then sequentially injects the slurry from the injection hole in the middle to the injection holes on the outer side into the fully - water - filled goaf, so as to realize the filling of the goaf, and further avoid the dangerous problems brought by ground collapse.

[0030] Furthermore, for the grouting method for a fully - water - filled goaf provided by the embodiment of the present invention, the slurry is sequentially injected from the injection hole in the middle to the injection holes on the outer side into the fully - water - filled goaf. Under the action of the water resistance in the goaf, the flow - diffusion range is relatively small, thus avoiding the loss of the slurry and saving costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0032] Figure 1 is one of the flow - chart diagrams of the grouting method for a fully - water - filled goaf provided by the embodiment of the present invention;

[0033] Figure 2 is another flow - chart diagram of the grouting method for a fully - water - filled goaf provided by the embodiment of the present invention;

[0034] Figure 3 is one of the structural diagrams of arranging grouting holes in the governance area provided by the embodiment of the present invention;

[0035] Figure 4 is another structural diagram of arranging grouting holes in the governance area provided by the embodiment of the present invention;

[0036] Figure 5 is the third structural diagram of arranging grouting holes in the governance area provided by the embodiment of the present invention;

[0037] Figure 6 It is the third schematic flow chart of the grouting method for a fully water-filled goaf provided by an embodiment of the present invention;

[0038] Figure 7 It is the fourth schematic flow chart of the grouting method for a fully water-filled goaf provided by an embodiment of the present invention;

[0039] Figure 8 It is the fifth schematic flow chart of the grouting method for a fully water-filled goaf provided by an embodiment of the present invention;

[0040] Figure 9 It is the sixth schematic flow chart of the grouting method for a fully water-filled goaf provided by an embodiment of the present invention;

[0041] Figure 10 It is a schematic diagram of injecting grouting material from the central injection hole to the outer injection holes of a fully water-filled goaf provided by an embodiment of the present invention. Among them, Figure a shows the grouting material filling the middle of the fully water-filled goaf, and Figure b shows the grouting material filling the entire fully water-filled goaf;

[0042] Figure 11 It is a schematic structural diagram of a fully water-filled goaf filled with the first aggregate provided by an embodiment of the present invention;

[0043] Figure 12 It is a schematic structural diagram of a fully water-filled goaf filled with the second aggregate provided by an embodiment of the present invention;

[0044] Figure 13 It is a schematic structural diagram of a fully water-filled goaf filled with slurry provided by an embodiment of the present invention.

[0045] Reference numerals:

[0046] 1, treatment area; 2, injection hole; 3, fully water-filled goaf; 4, first aggregate; 5, second aggregate; 6, slurry. Detailed implementation manners

[0047] The following further describes in detail the implementation manners of the present invention in conjunction with the accompanying drawings and embodiments. The following embodiments are used to illustrate the present invention, but cannot be used to limit the scope of the present invention.

[0048] In the description of the embodiments of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the embodiments of 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 construed as a limitation on the embodiments of the present invention. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0049] In the description of the embodiments of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0050] In the embodiments of the present invention, unless otherwise clearly specified and defined, the first feature being "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on" the second feature can be that the first feature is directly above or obliquely above the second feature, or simply means that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "under" the second feature can be that the first feature is directly below or obliquely below the second feature, or simply means that the first feature has a lower horizontal height than the second feature.

[0051] In the description of this specification, the description referring to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the embodiments of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0052] The following combines Figures 1 - 13 to describe the grouting method for a fully water-filled gob area in the embodiments of the present invention.

[0053] An embodiment of the present invention provides a grouting method for a fully - water - filled goaf, as follows: Figure 1 As shown, the grouting method includes the following steps:

[0054] Step 100: Arrange injection holes 2 in the treatment area 1 above the fully - water - filled goaf 3, and fill the aggregate into the fully - water - filled goaf 3 through the injection holes 2; wherein, there are multiple injection holes.

[0055] Step 200: Inject the slurry 6 into the fully - water - filled goaf 3 in sequence from the injection hole 2 in the middle to the injection holes 2 on the outside.

[0056] It can be understood that the goaf in this embodiment is a room - pillar goaf filled with water inside. The fully - water - filled goaf 3 is treated by grouting. First, arrange injection holes 2 communicating with the inside of the fully - water - filled goaf 3 in the treatment area 1 above the fully - water - filled goaf 3, then put the aggregate into the fully - water - filled goaf 3 through the injection holes 2, and finally inject the slurry 6 into the fully - water - filled goaf 3 in sequence from the injection hole 2 in the middle to the injection holes 2 on the outside.

[0057] It can be understood that during the process of injecting the slurry 6 into the fully - water - filled goaf 3 in sequence from the injection hole 2 in the middle to the injection holes 2 on the outside, the water in the fully - water - filled goaf 3 gradually overflows from the middle of the goaf to the surrounding under the action of the slurry 6. Then, when the slurry 6 is injected into the fully - water - filled goaf 3 through the outermost injection hole 2, the water in the fully - water - filled goaf 3 overflows. Thus, the aggregate and the slurry 6 are filled in the goaf, and the goaf is effectively filled by the combined body formed by the solidification of the slurry 6 and the aggregate.

[0058] It can be understood that in this embodiment, the fully - water - filled goaf 3 is treated by injecting aggregate and slurry 6 to fill the goaf space. The goaf after grouting can effectively improve its own stability, reduce internal disasters and surface subsidence, and facilitate the use of the land on the surface of the goaf.

[0059] The grouting method for a fully - water - filled goaf provided by the embodiment of the present invention fills the aggregate into the fully - water - filled goaf 3 through multiple injection holes 2, and then injects the slurry 6 into the fully - water - filled goaf 3 in sequence from the injection hole 2 in the middle to the injection holes 2 on the outside, thereby realizing the filling of the goaf and further avoiding the dangerous problems brought by ground collapse.

[0060] In an embodiment of the present invention, the distance between two adjacent injection holes 2 is 20m - 40m.

[0061] It should be noted that for the grouting of room-and-pillar goafs, peripheral holes (or curtain holes) can be constructed at the boundary of the treatment area first, and slurry is injected into the goaf boundary through the peripheral holes. On this basis, the construction of grouting holes inside the treatment area is carried out, and slurry is injected into the goaf through the grouting holes. The spacing between adjacent peripheral holes is relatively small, generally 5 - 10 m. Since the boundary of the treatment area is relatively long, the number of peripheral holes is large, thus increasing the engineering quantity. However, the full-water goaf grouting method provided by the embodiment of the present invention injects the slurry 6 into the full-water goaf 3 sequentially from the injection holes 2 in the middle to the injection holes 2 on the outside, and does not require the construction of peripheral holes (or curtain holes). The spacing between adjacent two injection holes 2 is 20 m to 40 m, thereby reducing the engineering quantity. And in this embodiment, under the action of water pressure, the pressure is uniform all around. After the slurry 6 enters the full-water goaf 3, under the action of water resistance, the flow and diffusion range is small, and the slurry 6 mostly accumulates near the bottom of the hole. Under the condition of low pump pressure or self-flow, the diffusion range of the slurry 6 can be effectively controlled, thereby avoiding the loss of the slurry 6 and saving costs.

[0062] In an embodiment of the present invention, the aggregate includes a first aggregate 4 and a second aggregate 5, and the particle size of the first aggregate 4 is larger than that of the second aggregate 5.

[0063] It can be understood that the aggregate can adopt granular materials such as slag, sand, and crushed stone. The aggregate can adopt any one of slag, sand, and crushed stone, or can also adopt a combination of two or three of slag, sand, and crushed stone.

[0064] In this embodiment, a mixture of slag, sand, and crushed stone is used as the aggregate. The mixture of slag, sand, and crushed stone is crushed and screened. The aggregate with a larger particle size is used as the first aggregate 4, and the aggregate with a smaller particle size is used as the second aggregate 5. In this embodiment, the aggregate with a particle size in the range of 5 mm to 10 mm is called coarse aggregate and used as the first aggregate 4; the aggregate with a particle size below 5 mm is called fine aggregate and used as the second aggregate 5.

[0065] In this embodiment, the grouting material for the goaf adopts aggregate and slurry 6. By first filling the full-water goaf 3 with aggregate and then filling it with slurry 6, the grouting material is mainly composed of aggregate and supplemented by slurry 6.

[0066] It can be understood that using slag, sand, and crushed stone as the aggregate has a lower cost, and by using the slag after mining, waste can be utilized, thereby saving the time and cost required for slag treatment while reducing costs.

[0067] In an embodiment of the present invention, the slurry 6 includes cement, fly ash, and loess. In this embodiment, the grouting material is mainly composed of low-cost slag, sand, crushed stone, etc., and supplemented by cement, fly ash, and loess.

[0068] Exemplarily, the amount of cement can be selected according to the strength requirements of the filling solid, and can be selected from 5% to 30% of the solid weight, and the concentration of the slurry 6 is 50%-60%. It should be noted here that the filling solid is the combined body formed by the slurry 6 and the aggregate after the slurry 6 solidifies after filling the goaf 3 full of water with the aggregate and the slurry 6.

[0069] It should be noted that in the prior art, the slurry injected into the peripheral holes needs to be formed by contacting the roof nearby, and special high-concentration (70%-80%) and quick-setting materials need to be prepared, and special grouting processes such as small flow rate, low pump pressure, and intermittent grouting are also required. The requirements for material ratio and grouting process are relatively high. Therefore, for the treatment of goafs, the engineering quantity of peripheral holes is large, the process is complex and the cost is high. However, in the grouting method for a goaf full of water provided by the embodiment of the present invention, the slurry 6 includes cement, fly ash and loess, and the concentration is a conventional 50%-60%. There is no need to add a quick-setting agent, and a conventional low-cost delivery pump can be selected, thereby simplifying the slurry preparation, delivery process and cost.

[0070] In an embodiment of the present invention, in the case where the aggregate includes the first aggregate 4 and the second aggregate 5, as Figure 2 shown, in step 100, the aggregate is filled into the goaf 3 full of water through the injection hole 2, which specifically includes the following steps:

[0071] Step 101, water and the first aggregate 4 are sequentially injected into the goaf 3 from the injection hole 2 in the middle to the injection hole 2 on the outside.

[0072] It can be understood that water is injected into the goaf 3 while the first aggregate 4 is put in from the injection hole 2 at the center of the treatment area 1 to the injection holes 2 around.

[0073] It should be noted that while the coarse aggregate is put into the goaf 3 through the injection hole 2, water is injected into the goaf 3 through the injection hole 2. The flowing water injected can make the coarse aggregate flow in the goaf, so as to realize the uniform arrangement of the coarse aggregate in the goaf 3 full of water.

[0074] As Figures 3 - 5 shown, a plurality of injection holes 2 are arranged in the treatment area 1. The injection hole 2 located in the middle of the treatment area 1 is used as the injection hole in the middle. One or more injection holes 2 can be arranged at the center of the treatment area 1 as the injection hole in the middle, as Figure 3 shown, showing the injection hole in the middle of the treatment area 1; all the injection holes 2 located outside the injection hole in the middle in the treatment area 1 are used as the injection holes on the outside. The injection holes on the outside are arranged in multiple circles with the injection hole in the middle as the center. The multiple circles are arranged radially along the injection hole in the middle, and a plurality of injection holes 2 are arranged in each circle. Figure 4 showing the arrangement of the grouting holes from the inside to the outside, Figure 5 showing the grouting holes in the entire treatment area 1.

[0075] Among them, the multi-ring injection holes are sequentially recorded as the first-ring injection holes, the second-ring injection holes, ... the nth-ring injection holes from the injection holes near the middle to the injection holes far from the middle. n represents the number of rings of the outer injection holes arranged. The first-ring injection holes, the second-ring injection holes, ... the nth-ring injection holes all include a plurality of injection holes arranged at intervals. The number of injection holes in the first-ring injection holes, the second-ring injection holes, ... the nth-ring injection holes may be equal or may not be equal. Of course, in this embodiment, the number of injection holes in the first-ring injection holes, the second-ring injection holes, ... the nth-ring injection holes increases sequentially. Preferably, all the injection holes are evenly distributed in the treatment area.

[0076] Exemplarily, coarse aggregate is put while injecting water from the injection holes in the middle to the middle of the full-water goaf 3, and then coarse aggregate is put while injecting water from the first-ring injection holes to the full-water goaf 3, and so on, coarse aggregate is put while injecting water from the second-ring injection holes, ... the nth-ring injection holes to the full-water goaf 3. It should be noted here that when filling the full-water goaf 3 through the i (i = 1, 2,... n)th-ring injection holes, each time coarse aggregate is put while injecting water from one injection hole to the full-water goaf 3, and all the injection holes of the i-th ring injection holes are sequentially passed along the circumferential direction to put coarse aggregate while injecting water into the full-water goaf 3.

[0077] Step 102: Inject water and the second aggregate 5 into the full-water goaf 3 in sequence from the injection holes in the middle to the outer injection holes.

[0078] It can be understood that from the injection holes 2 at the center of the treatment area 1 to the injection holes 2 around, water is injected while putting the second aggregate 5 into the full-water goaf 3, and the second aggregate 5 can be filled into the voids of the first aggregate 4. It should be noted here that the injection method of the second aggregate 5 is the same as that of the first aggregate 4, and the present invention will not elaborate here.

[0079] In an embodiment of the present invention, as Figure 6 shown, before step 101: Inject water and the first aggregate 4 into the full-water goaf 3 in sequence from the injection holes in the middle to the outer injection holes, the full-water goaf grouting method of this embodiment further includes the following steps:

[0080] Step 103: Determine the weight of the first aggregate 4 injected into the full-water goaf 3 by each injection hole 2 based on formula (1);

[0081] m1 = ρ1 f1 πr 2 h (1)

[0082] Among them, m1 represents the weight of the first aggregate 4; r represents the diffusion radius of the slurry; h represents the height of the full-water goaf 3; f1 represents the filling coefficient of the first aggregate 4; ρ1 represents the bulk density of the first aggregate 4.

[0083] It can be understood that before injecting the first aggregate 4, the weight m1 of injecting the first aggregate 4 into the water-filled goaf 3 through a single injection hole can be determined according to the single-hole filling volume V, the filling coefficient f1 of the first aggregate 4, and the bulk density ρ1 of the first aggregate 4. Among them, V = πr 2 h. Specifically, the weight m1 of the first aggregate 4 can be determined according to formula (1);

[0084] m1 = ρ1Vf1 = ρ1f1πr 2 h (1)

[0085] Furthermore, as Figure 7 shown, before steps 102, injecting water and the second aggregate 5 into the water-filled goaf 3 in sequence from the injection hole in the middle to the injection holes on the outside, the grouting method for the water-filled goaf in this embodiment further includes the following steps:

[0086] Step 104, determining the weight of the second aggregate 5 filled into the water-filled goaf 3 by each injection hole 2 based on formula (2);

[0087] m2 = πr 2 h f1k f2ρ2 (2)

[0088] Among them, m2 represents the weight of the second aggregate 5; r represents the diffusion radius of the slurry; h represents the height of the water-filled goaf 3; f1 represents the filling coefficient of the first aggregate 4; k represents the porosity of the pile body of the first aggregate 4; f2 represents the filling coefficient of the second aggregate 5; ρ2 represents the bulk density of the second aggregate 5.

[0089] It can be understood that before injecting the second aggregate 5, the weight m2 of injecting the second aggregate 5 into the water-filled goaf 3 through a single injection hole can be determined according to the single-hole filling volume V, the filling coefficient f1 of the first aggregate 4, the porosity k of the pile body of the first aggregate 4, the filling coefficient f2 of the second aggregate 5, and the bulk density ρ2 of the second aggregate 5. Specifically, the weight m2 of the second aggregate 5 can be determined according to the above formula (2).

[0090] It should be noted that Figure 7 it is shown that step 104 is executed before step 101. Of course, step 104 can also be executed after step 101.

[0091] In an embodiment of the present invention, as Figure 8 shown, step 200, injecting the slurry 6 into the water-filled goaf 3 in sequence from the injection hole in the middle to the injection holes on the outside, specifically includes the following steps:

[0092] Step 201, arranging the grouting pipeline in the injection hole in the middle, and the grouting pipeline extends into the water-filled goaf 3.

[0093] It can be understood that the slurry 6 is injected into the water-filled goaf 3 filled with the first aggregate 4 and the second aggregate 5 through the injection hole 2. In order to effectively disperse the slurry 6 in the voids between the first aggregate 4 and the second aggregate 5, a grouting pipeline is arranged in the grouting hole, and the slurry 6 is injected into the water-filled goaf 3 through the grouting pipeline.

[0094] Step 202: Inject the slurry 6 into the middle of the water-filled goaf 3 through the grouting pipeline.

[0095] Step 203: Move the grouting pipeline from the injection hole in the middle to the injection hole on the outside, and inject the slurry 6 into the outer area in the middle of the water-filled goaf 3 through the grouting pipeline.

[0096] It can be understood that the slurry tank can be connected to one end of the grouting pipeline. When it is necessary to grout the water-filled goaf 3, by placing the grouting pipeline in the grouting hole and the other end of the grouting pipeline extends into the water-filled goaf 3, the slurry 6 is injected into the water-filled goaf 3 through the grouting pipeline. In this embodiment, the grouting pressure can be 1.0 Mpa to 3.0 Mpa.

[0097] For example, the grouting pipeline is arranged in the injection hole in the middle, and the slurry 6 is injected into the water-filled goaf 3 through the grouting pipeline; then the grouting pipeline is moved to any one of the injection holes 2 in the first circle of injection holes 2, and the slurry 6 is injected into the water-filled goaf 3 through the grouting pipeline. The slurry 6 is injected into the water-filled goaf 3 through all the injection holes 2 in the first circle of injection holes 2 in sequence along the circumferential direction; and so on, the slurry 6 is injected into the water-filled goaf 3 through all the injection holes 2 in the second circle of injection holes,... the nth circle of injection holes.

[0098] It should be noted that during the process of grouting the water-filled goaf 3 through the injection hole in the middle, the flow and diffusion range is relatively small under the action of water resistance, and the slurry mostly accumulates near the bottom of the hole. Under the conditions of low pump pressure or self-flow, the diffusion range of the slurry can be effectively controlled, and the water in the middle of the goaf flows to the surrounding under the action of the slurry 6. During the process of injecting the slurry 6 into the goaf through the second circle of injection holes,... the nth circle of injection holes in sequence, the water in the goaf flows from the middle to the surrounding in sequence. It can be seen that during the process of grouting hole by hole from the center of the treatment area 1 to the surrounding, the water in the goaf flows from the middle to the surrounding in sequence. After the grouting is completed, the water in the goaf overflows from the goaf, so that the goaf is filled with the first aggregate 4, the second aggregate 5 and the slurry 6. After the slurry 6 solidifies, the stability of the goaf itself can be effectively improved, and internal disasters and surface subsidence can be reduced.

[0099] Further, in step 200, in order to achieve the effective diffusion of the grouting material in the voids between the first aggregate 4 and the second aggregate 5, the outlet of the grouting pipeline should not be placed on the roof of the goaf, but should be lowered into the interior of the aggregate in the goaf, so that there is a vertical distance between the lower end surface of the grouting pipeline and the bottom plate of the fully water-filled goaf 3, and this vertical distance can be 1 / 5 to 2 / 5 of the height of the fully water-filled goaf 3.

[0100] The following provides a specific method for grouting a fully water-filled goaf. Refer to Figure 9 As shown, this method for grouting a fully water-filled goaf includes the following steps:

[0101] Step 10: Determine the injection holes 2 in the treatment area 1 above the fully water-filled goaf 3.

[0102] It can be understood that multiple injection hole positions are determined in the treatment area 1 above the fully water-filled goaf 3. The diameter of the injection holes can be 200 mm - 300 mm, and the spacing between two adjacent injection holes is 20 - 40 m. Of course, the diameter of the injection holes can be adjusted according to the size of the aggregate, and the diameter of the injection holes is slightly larger than the size of the aggregate. Step 20: Determine the weight of the first aggregate 4 injected into the fully water-filled goaf 3 through each injection hole 2.

[0103] It can be understood that the weight m1 of the first aggregate 4 is determined based on formula (1);

[0104] m1 = ρ1 f1 πr 2 h (1)

[0105] Step 30: Determine the weight of the second aggregate 5 filled into the fully water-filled goaf 3 through each injection hole 2.

[0106] It can be understood that the weight m2 of the second aggregate 5 is determined based on formula (2);

[0107] m2 = πr 2 h f1 k f2 ρ2 (2)

[0108] It should be noted that step 20 and step 30 do not represent the order of execution of the steps. Step 20 and step 30 can be carried out simultaneously or independently.

[0109] Step 40: Process the injection holes 2, and inject water and the first aggregate 4 into the fully water-filled goaf 3 through the injection holes 2.

[0110] It is understandable that a charging hole is drilled at the middle position of the treatment area 1, and the first aggregate 4 is put while injecting water into the fully water-filled goaf 3 through this charging hole. Then, drilling is sequentially carried out from the middle position of the treatment area 1 to the outside, and after drilling, the first aggregate 4 is put while injecting water into the fully water-filled goaf 3 through this charging hole. That is, in this embodiment, a charging hole is formed every time drilling is carried out, and the first aggregate 4 is put while injecting water into the fully water-filled goaf 3 through this charging hole, so that drilling, water injection after drilling, and putting of the first aggregate are sequentially carried out from the middle of the treatment area 1 to the outside.

[0111] It should be noted that the drilling spacing in the treatment area 1 is 20 - 40 m, so that a plurality of charging holes 2 are formed in the treatment area 1, and the plurality of charging holes 2 are uniformly arranged from the center to the outside.

[0112] It is understandable that the grouting material is injected into the goaf from the center of the treatment area 1 to the outside through the charging hole 2, as Figure 10 shown, Figure 10 in FIG. a in Figure 10 illustrates that the grouting material fills to the middle of the fully water-filled goaf, and Figure 11 in FIG. b in

[0113] illustrates that the grouting material fills the entire fully water-filled goaf; if the grouting material is the first aggregate 4, the filling of the goaf with the first aggregate 4 is completed, as Figure 12 shown.

[0114] Step 50: The second aggregate 5 is put while injecting water into the fully water-filled goaf 3 from the charging hole in the middle to the charging holes on the outside, and the filling of the goaf with the second aggregate 5 is completed, as Figure 12 shown.

[0114] Step 60: The slurry 6 is injected into the fully water-filled goaf 3 from the charging hole in the middle to the charging holes on the outside in sequence.

[0115] It is understandable that grouting is carried out hole by hole from the center of the treatment area 1 to the periphery, and the grouting material is a mixed slurry of cement, fly ash, loess, etc. The amount of cement is selected according to the strength requirement of the filling solid body, and can be selected from 5% to 30% of the solid weight. The slurry-making concentration is 50% - 60%, and the grouting pressure is 1.0 - 3.0 MPa; in order to realize the effective diffusion of the grouting material in the voids between the first aggregate 4 and the second aggregate 5, the grouting pipeline is lowered into the aggregate inside the goaf, and the distance from the goaf floor is 1 / 5 - 2 / 5 times the goaf height, and the injection of the slurry 6 into the goaf is completed, as Figure 13 shown.

[0116] Step 70: The filled goaf is detected.

[0117] It is understandable that after filling, it is left standing for 1 - 3 months, and it is detected whether the filling rate of the goaf meets the requirements. If not, additional aggregate and grouting can be carried out.

[0118] Compared with the traditional grouting method, the full-water gob grouting method provided by the embodiment of the present invention adopts a grouting process of "from inside to outside", can prepare grouting slurry with a conventional ratio and concentration (50%-60%), does not require the addition of a quick-setting agent, and selects a conventional low-cost transfer pump, which simplifies the grouting slurry preparation, transportation process and cost; and removes the peripheral holes, and the number of drill holes is greatly reduced, and the number of drill hole construction can be reduced by more than 50%, so that the process is simplified, the project quantity is reduced, and the construction period is correspondingly reduced; the consumption of high-cost materials such as cement and fly ash used in the slurry 6 is greatly reduced, and the grouting material cost is reduced by more than 30%, thereby reducing the cost. It can be seen that the full-water gob grouting method provided by the embodiment of the present invention has the characteristics of simplifying the process, reducing the project quantity, saving the consumption of cementing materials, and saving costs.

[0119] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for grouting in a fully water-filled goaf, characterized in that Including: Arranging injection holes in the treatment area above the fully water-filled goaf, and filling the aggregate into the fully water-filled goaf through the injection holes; wherein, there are multiple injection holes, and the distance between two adjacent injection holes is 20m to 40m; Injecting the slurry into the fully water-filled goaf in sequence from the middle injection hole to the outer injection holes; the slurry includes cement, fly ash and loess, and the concentration of the slurry is 50%-60%; Wherein, the aggregate includes a first aggregate and a second aggregate, the particle size of the first aggregate is larger than that of the second aggregate, and filling the aggregate into the fully water-filled goaf through the injection holes includes: Injecting water and the first aggregate into the fully water-filled goaf in sequence from the middle injection hole to the outer injection holes; Injecting water and the second aggregate into the fully water-filled goaf in sequence from the middle injection hole to the outer injection holes; The injecting the slurry into the fully water-filled goaf in sequence from the middle injection hole to the outer injection holes includes: Arranging a grouting pipeline in the middle injection hole, and the grouting pipeline extends into the fully water-filled goaf; there is a vertical distance between the lower end surface of the grouting pipeline and the bottom plate of the fully water-filled goaf, and the vertical distance is 1 / 5 to 2 / 5 of the height of the fully water-filled goaf; Injecting the slurry into the middle of the fully water-filled goaf through the grouting pipeline; Moving the grouting pipeline from the middle injection hole to the outer injection hole, and injecting the slurry into the outer area in the middle of the fully water-filled goaf through the grouting pipeline.

2. The grouting method for a fully water-filled goaf according to claim 1, wherein Before injecting water and the first aggregate into the fully water-filled goaf in sequence from the middle injection hole to the outer injection holes, it further includes: Determining the weight of the first aggregate injected into the fully water-filled goaf by each injection hole based on formula (1); m1 = ρ1 f1πr 2 h (1) Wherein, m1 represents the weight of the first aggregate; r represents the diffusion radius of the slurry; h represents the height of the fully water-filled goaf; f1 represents the filling coefficient of the first aggregate; ρ1 represents the bulk density of the first aggregate.

3. The grouting method for a fully water-filled goaf according to claim 1, characterized in that, Before injecting water and the second aggregate into the fully water-filled goaf in sequence from the middle injection hole to the outer injection holes, it further includes: Determining the weight of the second aggregate filled into the fully water-filled goaf by each injection hole based on formula (2); m2 = πr 2 h f1k f2ρ2 (2) Wherein, m2 represents the weight of the second aggregate; r represents the diffusion radius of the slurry; h represents the height of the fully water-filled goaf; f1 represents the filling coefficient of the first aggregate; k represents the porosity of the pile body of the first aggregate; f2 represents the filling coefficient of the second aggregate; ρ2 represents the bulk density of the second aggregate.

4. The grouting method for a fully water-filled goaf according to any one of claims 1 to 3, characterized in that, The aggregate includes at least one of slag, sand, and crushed stone, and / or The slurry includes cement, fly ash and loess, and the concentration of the slurry is 50%-60%.

5. The full water goaf grouting method according to any one of claims 1 to 3, characterized in that, The outer injection holes are arranged in multiple circles with the middle injection hole as the center.

6. The grouting method for a fully water-filled goaf according to any one of claims 1 to 3, characterized in that, When injecting the slurry into the fully water-filled goaf in sequence from the middle injection hole to the outer injection holes, the grouting pressure is 1.0Mpa to 3.0Mpa.

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