Underwater filling reinforcement boundary control structure and method for water-rich goaf

Abstract

The invention discloses a water-rich goaf underwater filling reinforcement boundary control structure and method. The problem that during underwater grouting, a governing boundary is not easy to control, and grout flows outwards due to grout flowing and dispersing factors is solved. According to the technical scheme, the structure comprises a curtain grout stop wall, a partition wall and a grout filling area; the curtain grout stopping wall is arranged in the boundary range of goaf treatment and used for preventing grout from flowing out; the partition walls are arranged in the inner space of the curtain grout stopping wall, the number of the partition walls is multiple, and the adjacent partition walls are spaced by a set distance. The grout filling areas are defined by partition walls and curtain grout stopping walls, and the goaf is divided into a plurality of relatively independent grout filling areas through the curtain grout stopping walls and the partition walls.

Description

Technical Field

[0001] The invention belongs to the technical field of geological disaster control, and particularly relates to a boundary control structure and method for underwater filling and reinforcement of a water-rich goaf. Background Technique

[0002] The statements in this part only provide background technical information related to the present invention, and do not necessarily constitute prior art.

[0003] After underground mineral resources are mined, specific cavity areas, namely goafs, will be left underground. The existence of goafs will change the original stress balance state underground, leading to problems such as roof collapse and surface settlement. Therefore, we need to carry out goaf treatment. In the goaf treatment work, situations where the cavity area is wide and there is a lot of accumulated water are often faced. Such goafs usually have characteristics such as large scope, deep depth, and complex geological conditions. When using traditional grouting reinforcement technology to treat them, due to the relatively open space outside the goaf treatment boundary and the difficulty in accurately controlling the flow of the slurry, it is easy to cause a large amount of slurry to overflow into non-treatment areas. In addition, when treating underwater, there are also problems such as easy dispersion of the slurry and difficulty in coagulation in water. These problems will not only significantly increase the treatment cost of the goaf, cause a large waste of grouting materials, but also cause delays in the construction period, thereby affecting the overall efficiency and quality of the goaf treatment work. Summary of the Invention

[0004] Aiming at the above problems, the present invention provides a boundary control structure and method for underwater filling and reinforcement of a water-rich goaf, which solves the problems of difficult control of the treatment boundary during underwater grouting and slurry outflow caused by slurry flow and dispersion factors, and reduces the grouting cost of different regions while ensuring the isolation effect of the boundary.

[0005] In order to achieve the above object, the present invention is realized through the following technical solutions:

[0006] In a first aspect, the present invention provides a boundary control structure for underwater filling and reinforcement of a water-rich goaf, including: a curtain grout stop wall, a partition wall, and a slurry filling area; the curtain grout stop wall is arranged at the boundary range of the goaf treatment for preventing slurry from flowing out; the partition wall is arranged in the internal space of the curtain grout stop wall, and multiple partition walls are provided, with a set distance between adjacent partition walls; the slurry filling area is surrounded by the partition wall and the curtain grout stop wall, and the goaf is divided into several relatively independent slurry filling areas by the curtain grout stop wall and the partition wall together; the curtain grout stop wall is formed by pouring underwater grout stop wall construction materials and grouting boundary control materials; the slurry filling area is formed by pouring underwater anti-dispersion grouting filling materials.

[0007] Furthermore, the construction material of the underwater grout curtain wall consists of ordinary cement and grouting material for the grout curtain wall; the grouting material for the grout curtain wall includes water glass, water reducer, and anti-dispersion agent;

[0008] The volume ratio of the construction material of the underwater grout curtain wall to the grouting boundary control material is 1:1 to 3:1, and the ratio of the mass of water to the mass of cement in the cement slurry is 0.5:1.0 to 0.8:1.0.

[0009] Furthermore, the material used for the partition wall is exactly the same as the material used for the curtain grout curtain wall.

[0010] Furthermore, the underwater anti-dispersion grouting filling material consists of ordinary cement, fly ash, water, and anti-dispersion agent. The ratio of water, ordinary cement, and fly ash is (0.5 - 1.0):(0.6 - 0.9):(0.4 - 0.1). The underwater retention rate of the underwater anti-dispersion grouting filling material is greater than 85%, and the proportion of the anti-dispersion agent in the dry material of the underwater anti-dispersion grouting filling material is ≤1%.

[0011] Furthermore, the grouting boundary control material is a super-high expansion grouting material.

[0012] In the second aspect, the present invention also provides a method for controlling the boundary of underwater filling and reinforcement in a water-rich goaf area, including:

[0013] S1. Arrange row-by-row and set-spacing curtain grout curtain wall grouting holes around the goaf area to be treated; when the goaf area is large, construct a row of partition wall grouting holes at every set distance; when constructing the drill site, first conduct borehole detection to ensure that the drill site will not penetrate the goaf area and will not affect the borehole construction, otherwise select another location or take measures;

[0014] S1. Establish a grouting station and a grouting system, and conduct a trial operation, and then conduct a pressure test on the grouting pipeline;

[0015] S2. Prepare the construction material of the underwater grout curtain wall; grout the curtain grout curtain wall grouting holes, using the construction material of the underwater grout curtain wall and the grouting boundary control material. After reaching the single-hole grouting set standard, end the grouting of this hole to form a curtain grout curtain wall. If it is difficult to form, adjust the on-site mix ratio according to the grouting material and dynamically adjust the final hole spacing;

[0016] S3. Grout the partition wall grouting holes, using the construction material of the underwater grout curtain wall and the grouting boundary control material. After a single hole reaches the grouting set standard, end the grouting of this hole, check for any missed grouting, and form a partition wall;

[0017] S4. After the formation of the curtain grout stop wall and the partition wall, drill grouting holes for the filling area within the range of the slurry filling area, grout the grouting holes for the filling area, end the grouting of the hole after reaching the set standard for single-hole grouting, check for any ungrouted phenomenon, set up drainage channels or drainage holes during grouting, and adopt the top-down alternate-hole and sequential grouting process;

[0018] S5. During the construction process, drill holes at any time to inspect the grouting effect. After all the grouting holes are completed, analyze the grouting records and arrange inspection holes, and use the grouting method for inspection.

[0019] Furthermore, when drilling inspection holes, the whole hole should be cored, and the core recovery rate for each run should be greater than 80%. When coring the caving zone of the goaf, a double-layer core barrel should be used.

[0020] Furthermore, during the treatment construction of the goaf, it should be monitored once every 7 days; within 3 months after the end of the treatment construction, it should be monitored once every half month, and then once every month thereafter.

[0021] Furthermore, when using the grouting method for inspection, the treatment effect of the goaf should be quantitatively evaluated according to the grouting volume in combination with the element characteristics of the goaf and the design requirements. The grouting material for inspection should be underwater anti-dispersion grouting filling material. The end condition should be that the slurry volume injected into the hole per unit time is less than 5 L / min, the grouting duration is 5 - 10 min, the final hole pressure is 2 - 3 MPa, and the grouting volume is less than 10% of the average construction grouting volume, then the design requirements are met.

[0022] Furthermore, when constructing the drill site, if the drill site is to penetrate the goaf or affect the drilling construction, the measures to be taken include but are not limited to changing the location of the drill site and strengthening the periphery of the drill site to ensure that the subsequent drilling construction is not affected.

[0023] Compared with the prior art, the advantages and positive effects of the present invention are:

[0024] A water-rich goaf underwater filling and reinforcement boundary control structure provided by the present invention sets a curtain grout stop wall within the boundary range of the goaf treatment, controls the treatment boundary, plays a sealing role, and can effectively prevent the outflow of slurry. This not only saves costs but also improves the grouting treatment effect and shortens the construction period. A partition wall is provided for the large space inside the curtain grout stop wall, dividing a large-scale treatment area into small grouting units. Zonal treatment can effectively adjust the grouting parameters according to different conditions and situations, and improve the grouting treatment effect.

[0025] In view of the characteristics that the fluidity of underwater grouting in the goaf is uncontrollable and the material is easily dispersed in water and difficult to solidify and form, the present invention adopts a material with quick setting and controllability and anti-dispersion, which can better coagulate and form in water and is more suitable for the situation of underwater grouting. Different grouting materials are used for the curtain grout stop wall, the partition wall and the slurry filling area. Among them, the same grouting material is used for the curtain grout stop wall and the partition wall, which are both formed by double-fluid grouting of the grouting boundary control material and cement + controllable and anti-dispersion grouting material; the slurry filling area adopts the slurry of ordinary cement + fly ash + anti-dispersion grouting material. The material used in the filling area has a relatively low cost, and at the same time, it can ensure that the strength and other requirements are met. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings forming a part of this specification are used to provide a further understanding of the present invention. The schematic embodiments and descriptions thereof of the present invention are used to explain the present invention and do not constitute an improper limitation to the present invention.

[0027] Figure 1 It is the underwater filling and reinforcement boundary control structure of the water-rich goaf of the present invention;

[0028] Figure 2 It is a schematic plan view of the grouting borehole layout in the filling and reinforcement area.

[0029] In the figure: 1. Curtain grout stop wall; 2. Partition wall; 3. Slurry filling area; 4. Grouting hole in the filling area. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] It should be noted that the following detailed description is illustrative and is intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs.

[0031] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the present invention otherwise clearly indicates, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof;

[0032] This embodiment provides an underwater filling and reinforcement boundary control structure for a water-rich goaf, as Figure 1 - Figure 2As shown in the figure, it includes: a curtain grout-stop wall, a partition wall, and a grout filling area; the curtain grout-stop wall is arranged at the boundary of the mined-out area treatment to prevent grout from flowing out; the partition wall is arranged inside the inner space of the curtain grout-stop wall, and there are multiple partition walls with a set distance between adjacent partition walls; the grout filling area is enclosed by the partition wall and the curtain grout-stop wall, and the mined-out area is divided into several relatively independent grout filling areas by the curtain grout-stop wall and the partition wall together.

[0033] Specifically, the curtain grout-stop wall is formed by pouring underwater grout-stop wall construction materials and grouting boundary control materials. The underwater grout-stop wall construction materials are composed of ordinary cement and grout-stop wall grouting materials; the grout-stop wall grouting materials include water glass, water reducer, and anti-dispersant.

[0034] The volume ratio of the underwater grout-stop wall construction materials to the grouting boundary control materials is 1:1 to 3:1. The ratio of the mass of water to the mass of cement in the cement slurry is 0.5:1.0 to 0.8:1.0, and the setting time is 5s to 180s, which can be adjusted according to the on-site situation. The ordinary cement is of grade 32.5, which is convenient for the grout to meet the requirements such as quick setting and controllability, and good anti-dispersibility.

[0035] Specifically, the materials used for the partition wall are exactly the same as those used for the curtain grout-stop wall.

[0036] Furthermore, the grout filling area is formed by pouring underwater anti-dispersant grouting filling materials. The underwater anti-dispersant grouting filling materials are composed of ordinary cement, fly ash, water, and anti-dispersant. The ratio of water, ordinary cement, and fly ash is (0.5 - 1.0):(0.6 - 0.9):(0.4 - 0.1). The ordinary cement is of grade 32.5, and the fly ash meets the national secondary and tertiary quality standards. The underwater retention rate of the underwater anti-dispersant grouting filling materials is greater than 85%. The proportion of anti-dispersant in the dry materials of the underwater anti-dispersant grouting filling materials is ≤1%. The grout ratio is determined according to on-site tests.

[0037] Specifically, the grouting boundary control material is a super-high expansion grouting material and is a single-liquid grouting. The liquid-solid ratio is 2:1 to 3:1, the material expansion ratio is greater than 50 times, and it is green, safe, and non-toxic. The actual dosage is determined according to the on-site situation. The super-high expansion grouting material selects existing materials, such as the super-high expansion grouting material disclosed in the patent with the publication number CN110835449B.

[0038] This embodiment also provides a method for controlling the boundary of underwater filling and reinforcement in a water-rich mined-out area, including:

[0039] S1. Arrange grouting holes for the curtain grout stop wall in rows with a set spacing around the gob area to be treated; when the gob area is large, construct a row of partition wall grouting holes at intervals of a set distance; when constructing the drilling site, first conduct borehole detection to ensure that the drilling site will not penetrate the gob area and will not affect the borehole construction. Otherwise, select another location or take measures to ensure that the constructed drilling site will not affect the subsequent borehole construction;

[0040] S1. Establish a grouting station and a grouting system, and conduct a trial operation. Then, conduct a pressure test on the grouting pipeline; the grouting station and the grouting system consist of a material yard, a primary mixing tank, a secondary mixing tank, a water supply system, a batching sub-station, a grouting pump, a pressure gauge, a hole-sealing device, and a grouting pipeline;

[0041] S2. Prepare the construction materials for the underwater grout stop wall; use a double-fluid grout of ordinary cement + controllable and anti-dispersive grouting materials. Determine the dosages of water glass and anti-dispersive materials according to on-site tests to meet the requirements of controllable quick setting and good anti-dispersibility of the grout; conduct grouting on the grouting holes of the curtain grout stop wall, and use the construction materials for the underwater grout stop wall and the grouting boundary control materials. After reaching the set standard for single-hole grouting, end the grouting of this hole to form a curtain grout stop wall. If it is difficult to form, adjust the on-site mix ratio according to the grouting materials and dynamically adjust the final hole spacing;

[0042] S3. Conduct grouting on the partition wall grouting holes, and use the construction materials for the underwater grout stop wall and the grouting boundary control materials. After a single hole reaches the set standard for grouting, end the grouting of this hole, and check for any missed grouting to form a partition wall;

[0043] S4. After the curtain grout stop wall and the partition wall are formed, drill filling area grouting holes within the range of the grout filling area, conduct grouting on the filling area grouting holes, and end the grouting of this hole after reaching the set standard for single-hole grouting. Check for any missed grouting. Set up a drainage channel or drainage holes during grouting to squeeze out the goaf cavity or fissure water from the grouting area during grouting, so that the goaf can be effectively filled. The grouting of each grout filling area should adopt the top-down and alternate-hole-by-hole sequential grouting process to check the diffusion radius and grouting effect during grouting and adjust the grouting hole spacing in a timely manner;

[0044] S5. Conduct borehole construction at any time during the construction process to inspect the grouting effect. After all grouting holes are completed, analyze the grouting records and arrange inspection holes, and use the grouting method for detection.

[0045] Specifically, when drilling inspection holes, core samples should be taken for the entire hole. The opening hole diameter should be larger than the set size of the final hole diameter. The core recovery rate for each run should be greater than 80%. When taking cores from the caving zone of the goaf, a double-layer core barrel should be used. The construction technology of the inspection holes shall be implemented in accordance with the "Technical Specification for Highway Design and Construction in Goaf Areas" (JTG T 3331—2024).

[0046] Specifically, during the treatment construction of the goaf, monitoring should be carried out once every 7 days; within 3 months after the end of the treatment construction, monitoring should be carried out once every half month, and then once every month. When using the grouting method for detection, the treatment effect of the goaf should be quantitatively evaluated according to the grouting volume in combination with the element characteristics of the goaf and the design requirements. The grouting material used for detection is the underwater anti-dispersive grouting filling material. The end condition should be that the grout volume injected into the hole per unit time is less than 5 L / min, the grouting duration is 5 - 10 min, the final hole pressure is 2 - 3 MPa, and when the grouting volume is less than 10% of the average construction grouting volume, the design requirements are met.

[0047] Specifically, when constructing the drilling site, if the drilling site is to penetrate the goaf or affect the drilling construction, the measures to be taken include but are not limited to changing the location of the drilling site and strengthening the periphery of the drilling site to ensure that the subsequent drilling construction is not affected.

[0048] Although the specific implementation manners of the present invention have been described above in conjunction with the accompanying drawings, it is not a limitation to the protection scope of the present invention. Those skilled in the art should understand that based on the technical solutions of the present invention, various modifications or deformations that can be made without creative efforts by those skilled in the art are still within the protection scope of the present invention.

Claims

1. A water-rich empty area underwater filling reinforcement boundary control structure, characterized in that: include: Curtain stop walls, partition walls and grout filling areas; The curtain slurry stop wall is arranged at the boundary range of the goaf area management to prevent the outflow of slurry; the partition wall is arranged in the internal space of the curtain slurry stop wall, and the partition wall is provided with multiple sections, and adjacent partition walls are spaced at a set distance; the slurry filling area is surrounded by the partition wall and the curtain slurry stop wall, and the goaf area is divided into several relatively independent slurry filling areas by the curtain slurry stop wall and the partition wall; the curtain slurry stop wall is formed by pouring underwater slurry stop wall construction materials and grouting boundary control materials; the slurry filling area is formed by pouring underwater anti-dispersion grouting filling materials.

2. The underwater filling reinforcement boundary control structure for water-rich empty areas according to claim 1, characterized in that: The underwater grout-stopping wall construction material is composed of ordinary cement and grout-stopping wall grouting material; the grout-stopping wall grouting material includes water glass, water reducing agent, and anti-dispersion agent; The volume ratio of the underwater grout-stopping wall construction material to the grouting boundary control material is 1:1 to 3:1, and the ratio of the water mass to the cement mass of the cement slurry is 0.5:1.0 to 0.8:1.

0.

3. The underwater filling reinforcement boundary control structure for water-rich empty areas according to claim 1, characterized in that: The material used for the partition wall is exactly the same as the material used for the curtain mortar stop wall.

4. The underwater filling reinforcement boundary control structure for water-rich empty areas according to claim 1, characterized in that: The underwater anti-dispersion grouting filling material is composed of ordinary cement, fly ash, water and anti-dispersion agent, and the ratio of water, ordinary cement and fly ash is (0.5-1.0):(0.6-0.9):(0.4-0.1). The underwater retention rate of the underwater anti-dispersion grouting filling material is greater than 85%, and the proportion of anti-dispersion agent in the dry material of the underwater anti-dispersion grouting filling material is ≤1%.

5. The underwater filling reinforcement boundary control structure for water-rich empty areas as claimed in claim 2, characterized in that: The grouting boundary control material is an ultra-high expansion grouting material.

6. A method for controlling the underwater filling and reinforcement boundary of a water-rich empty area based on the underwater filling and reinforcement boundary control structure of a water-rich empty area according to any one of claims 1 to 5, characterized in that: include: S1. Arrange rows of curtain grouting holes with set spacing around the goaf to be treated; when the goaf is large, construct a row of partition wall grouting holes at set intervals; conduct drilling detection before drilling to ensure that the drilling site will not expose the goaf and will not affect the drilling construction, otherwise select another location or take measures; S1. Establish a grouting station and grouting system, and conduct a trial run, and then conduct a pressure test on the grouting pipeline; S2. Prepare underwater grouting wall construction materials; grout the curtain grouting wall grouting holes, use underwater grouting wall construction materials and grouting boundary control materials, and finish grouting the hole after reaching the single hole grouting setting standard to form a curtain grouting wall. If it is difficult to form, adjust the on-site mix ratio according to the grouting materials and dynamically adjust the final hole spacing; S3. Grouting is performed on the grouting holes of the partition wall, using underwater grouting wall construction materials and grouting boundary control materials. Grouting of a single hole is terminated after the grouting standard is reached, and any leakage is checked to form a partition wall; S4. After the curtain grouting wall and the partition wall are formed, grouting holes are drilled in the grouting area, and grouting is performed on the grouting holes in the filling area. Grouting of the holes is terminated after the single hole grouting setting standard is reached. Check for leakage. Drainage channels or drainage holes are set during grouting, and a top-down grouting process is adopted for each hole in sequence. S5. During the construction process, drilling holes should be carried out at any time to check the grouting effect. After all grouting holes are completed, the grouting records should be analyzed, and test holes should be arranged, and the grouting method should be used for testing.

7. A method for controlling the boundary of underwater filling and reinforcement of water-rich empty areas as claimed in claim 6, characterized in that: When drilling a test hole, the entire hole should be cored, and the core sampling rate each time should be greater than 80%. Double-layer core tubes should be used when coring the collapsed zone in the goaf.

8. A method for controlling the boundary of underwater filling and reinforcement of water-rich empty areas as claimed in claim 7, characterized in that: The goaf area should be monitored once every 7 days during the treatment construction period; once every half month within 3 months after the treatment construction is completed, and once a month thereafter.

9. A method for controlling the boundary of underwater filling reinforcement in a water-rich void area as claimed in claim 6, characterized in that: When using the grouting method for detection, the treatment effect of the goaf should be quantitatively evaluated based on the grouting volume combined with the characteristics of the goaf elements and design requirements. The detection slurry uses underwater anti-dispersion grouting filling materials. The termination conditions should be that the slurry volume injected into the hole per unit time is less than 5L / min, the grouting duration is 5-10min, the final hole pressure is 2-3MPa, and the grouting volume is less than 10% of the average construction grouting volume to meet the design requirements.

10. A method for controlling the boundary of underwater filling and reinforcement of water-rich empty areas as claimed in claim 1, characterized in that: During the construction of the drilling site, if the drilling site is to expose the goaf or affect the drilling construction, the measures to be taken include but are not limited to changing the location of the drilling site and reinforcing the area around the drilling site to ensure that it does not affect the subsequent drilling construction.

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