Staged grouting, filling and sealing method for water bursting and caving of underground chamber roof

Abstract

The invention provides a staged grouting, filling and sealing method for underground chamber roof water bursting and caving, and belongs to the field of underground chamber roof caving area governing. According to the method, firstly, a chamber roof is constructed to fill a supporting framework, and the junction position of a chamber and a roof caving area is sealed through a wood formwork; grouting pipes in different stages are buried according to reasonable design, and first-stage high-strength concrete filling, second-stage cement mortar filling and third-stage double-liquid-slurry grouting are conducted in sequence. Through the staged filling and grouting technology, on one hand, support is provided for unstable rocks of a top plate, and fractured rock masses are connected into a whole to form a complete stress arch; and on the other hand, grouting is conducted on a water-containing fissure zone by combining construction of a filling grouting pipe and drilling, a water outlet point is blocked, and meanwhile broken rock mass in deep surrounding rock is reinforced, so that the stability of a chamber top plate is guaranteed, gushing water is reduced through blocking, and the comfort level and safety of the working environment of personnel and equipment in the underground chamber are improved.

Description

Technical Field

[0001] The invention relates to the technical field of underground chamber roof fall-off area management, and in particular to a staged grouting filling and sealing method for underground chamber roof water gushing-off area. Background Art

[0002] During the development of large permanent chambers in mines, if the surrounding rock is unstable or passes through a large water-bearing fracture zone, the roof is very likely to collapse over a large area. The height of the collapse is affected by the degree of rock fragmentation and often collapses to several meters or even tens of meters. In severe cases, it will lead to the upper geological structure or existing projects, causing great safety hazards. The treatment of the empty area of ​​the underground chamber roof must not affect the function of the original chamber and must ensure the safety of the chamber roof. If it is under water-rich and complex hydrogeological conditions, it will further increase the difficulty of handling the empty area.

[0003] In the prior art, the treatment technology for the empty area of ​​the cavern roof is usually mainly grouting and filling. Among them, the filling technology is usually to construct the side wall or the internal empty area of ​​the rock mass with a small exposed opening. It is difficult to solve the roof treatment and the caved-in area with a large exposed area through traditional filling construction methods. The main function of the existing grouting construction process is to reinforce the rock formation and control water gushing, but it is greatly restricted by the operation site. When reinforcing the rock formation, it is often necessary to drill holes at a long distance. For example, the invention patent (application number CN 202310672818.7) discloses a three-dimensional grouting method based on the distribution of spatial voids in the caved-in area. By arranging long grouting holes at a long distance, three-dimensional grouting is carried out to achieve the treatment of the caved-in area; however, when controlling water gushing by grouting, it is also required that the top rock is relatively intact and can withstand sufficient grouting pressure. In the area where water is gushing from the roof of the underground chamber, on the one hand, the filling body is prone to collapse due to the large exposed void area on the top, and the water environment is likely to change the properties of the filling body, making the filling construction more difficult; on the other hand, the rock on the top of the falling area is broken and continuously collapses, making it impossible to grout from the bottom, and there is a lack of a stable rock cap, which cannot bear the grouting pressure and is prone to large amounts of grouting.

[0004] Therefore, it is necessary to develop a method for controlling the roof collapse area of ​​underground chambers to overcome the difficulties of filling construction in the water-sprinkling roof collapse area and grouting construction of the rock-broken roof, solve the problem of controlling the roof collapse area of ​​underground chambers, ensure construction safety and achieve safety and stability of the chamber roof. Summary of the invention

[0005] In view of the technical problems existing in the background technology, the present application provides a method for phased grouting filling and sealing of the water gushing out area of ​​the underground chamber roof, aiming to solve the technical problems that the filling construction of the water gushing out area of ​​the underground chamber roof and the grouting construction of the rock-broken roof are difficult to implement, and the construction safety and stability of the chamber roof cannot be guaranteed.

[0006] In a first aspect, an embodiment of the present application provides a method for sealing a water gushing area of ​​a underground chamber roof by grouting and filling in stages, characterized in that it comprises the following steps:

[0007] S1. Refer to the design outline of the cavern, construct and fill the supporting frame on its roof, and use wooden formwork to seal the junction between the cavern and the empty area;

[0008] S2, 1# grouting pipe, 2# grouting pipe and 3# grouting pipe with increasing buried depth from the chamber, the lower openings of the 1# grouting pipe, 2# grouting pipe and 3# grouting pipe are all fixed on the filling support frame;

[0009] S3, filling the first stage of high-strength concrete from the 1# grouting pipe, using the 2# grouting pipe as an overflow pipe, and stopping the first stage of high-strength concrete filling after the grouting from the 2# grouting pipe is discharged;

[0010] S4, after the first stage high-strength concrete of step S3 is initially set, the second stage cement mortar filling is carried out from the 2# grouting pipe, and the 3# grouting pipe is used as an overflow pipe, and the second stage cement mortar filling is stopped after the 3# grouting pipe discharges slurry;

[0011] S5. Arrange curtain drillings from a stable location in the chamber or surrounding tunnels to the water-bearing fracture zone above the roof caving area; after the curing of the first-stage high-strength concrete in step S3 and the second-stage cement mortar in step S4 is completed, perform the third-stage double-liquid grouting from the 3# grouting pipe, using the curtain drillings as exhaust holes, and stop the third-stage double-liquid grouting until slurry flows out of the curtain drillings, thus completing the staged grouting, filling and sealing of the water gushing area of ​​the underground chamber roof.

[0012] In the technical solution of the embodiment of the present application, in order to solve the problem of large-scale roof collapse caused by crossing a large water-containing fracture zone during the development of a large permanent chamber in a mine, a first-stage high-strength concrete filling is performed to form an overall concrete support structure, and a stable force foundation is provided for the next filling step. The second-stage cement mortar filling is performed to basically seal the empty area to form a stable filling body, which is bonded with the surrounding rock to form an overall load-bearing structure to prevent further roof collapse. The third-stage double-liquid grouting is performed to seal the water-containing fracture zone of the fault, and the broken rock mass is bonded as a whole, thereby reinforcing the surrounding rock while blocking water. This application uses the staged filling and grouting technology to, on the one hand, provide support for the unstable rock on the roof and connect the broken rock mass into a whole to form a complete stress arch; on the other hand, combined with the construction of filling grouting pipes and drilling holes, grouting is carried out on the water-bearing fracture zone to seal the water outlet and reinforce the broken rock mass in the deep surrounding rock, thereby ensuring the stability of the chamber roof, sealing and reducing water gushing, and helping to improve the comfort and safety of the working environment of personnel and equipment in the underground chamber.

[0013] In some embodiments, in step S2, the 1# grouting pipe is buried at the lower edge of the chamber arch foot, and the 1# grouting pipe is arranged horizontally; the 2# grouting pipe is buried at the highest point of the chamber arch, and the 2# grouting pipe is arranged vertically; the 3# grouting pipe is buried in the arch, and its upper opening extends to the lowest point of the top crack of the caving area. The length of the 1# grouting pipe is 0.4 to 0.6m, the upper opening of the 2# grouting pipe is buried 0.4 to 0.6m above the highest point of the chamber arch, and a pressure gauge is installed at the inlet (lower opening) of the 3# grouting pipe.

[0014] In this embodiment, by reasonably designing the size, position and function of the grouting pipes in different stages, the previous construction stage can provide good support for the next construction stage, so that the top plate in each stage is always in a safe and reliable state, avoiding personnel working in the falling area, ensuring the safety of construction personnel, and preventing roof falls and object impact accidents.

[0015] In some embodiments, in step S5, the aperture of the curtain drilling is 80-100 mm, and the number of the curtain drilling holes is determined according to the number of fractures in the water-bearing fracture zone development area above the roof caving area, and the ratio of the number of the curtain drilling holes to the number of the fractures is (2-2.5):1. Before the third stage of double-liquid grouting, the curtain drilling can be used for early drainage. The curtain drilling is constructed from the chamber or the surrounding tunnel to the water-bearing fracture zone development area above the roof caving area. The main considerations for selecting the opening position include: the rock is stable and complete, the opening position is convenient for drainage, it does not affect the later function of the chamber, and it is as close to the upper part of the roof caving area as possible to reduce the drilling construction workload.

[0016] In this embodiment, curtain drilling is arranged in the area with developed water-bearing fracture zones above the caving area, which serves to cut off part of the water source. It can drain water in advance while providing exhaust holes for grouting, preventing a large amount of fracture water from reducing the concentration of the grouting body and causing slurry leakage, thereby improving the grouting effect.

[0017] In some embodiments, in step S5, in the third stage of double-liquid grouting, the final grouting pressure is 2 to 2.5 times the hydrostatic pressure. If the hydrostatic pressure is less than 4 MPa, 8 to 10 MPa is used as the final grouting pressure. The curing time of the first stage high-strength concrete and the second stage cement mortar is 8 to 12 days.

[0018] In this embodiment, the final pressure of the third stage dual-liquid grouting is limited to ensure that the grouting achieves the expected effect. The curtain drilling hole is used as the exhaust hole, and the outflow of a small amount of slurry from the exhaust hole is used as the visual critical point for the end of grouting, thereby ensuring the effect of grouting in sealing cracks.

[0019] In some embodiments, in the first stage of high-strength concrete filling, concrete with a strength of C40 or above is used, in the second stage of cement mortar filling, cement mortar with a strength of C20 is used, and in the third stage of double-liquid grouting, the grouting material is a double-liquid slurry of cement and water glass.

[0020] In this embodiment, by limiting the raw materials for filling and grouting in different stages, the previous construction process can provide good support for the next construction process, so that the roof is always in a safe and reliable state during the construction of each stage; in addition, this method of filling and grouting in stages, through the determination of the visible critical point of construction, determines the stage of construction based on the actual engineering phenomena on site, and uses it as the basis for determining the next step of construction, thereby achieving accurate grasp of the construction time and construction steps, and providing a practical and effective method for the treatment of caving areas in large underground chambers.

[0021] In some embodiments, in step S2, the diameters of the 1# grouting pipe, the 2# grouting pipe and the 3# grouting pipe are 80-100 mm.

[0022] In some embodiments, in step S1, the filling support frame is prepared according to the specification and shape of the chamber, and is composed of a plurality of U-shaped steel arch beams and a plurality of fixed cross beams.

[0023] In this embodiment, U-shaped steel arch beams and fixed cross beams are manufactured according to the specifications and shapes of the chamber as a filling support skeleton. On the one hand, a reliable fixed end is provided for the burial of the grouting filling pipe, so that the grouting filling pipe can be fixed to the corresponding position according to the needs of phased construction; on the other hand, basic support is provided for poor roof slabs, and reliable boundary constraints are provided for the formation of an artificial false roof during the first-stage filling, reducing the risk of large-scale roof collapse.

[0024] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solution of the present application, the following is a brief introduction to the drawings used in the present application. Obviously, the drawings described below are only some embodiments of the present application, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0026] Figure 1 It is a schematic diagram of a staged grouting and filling sealing method for water gushing and falling areas of underground chamber roof in an embodiment of the present application;

[0027] Explanation of the reference numerals: 100 - chamber; 110 - first stage high-strength concrete filling; 120 - second stage cement mortar filling; 130 - third stage double-liquid grouting; 140 - 1# grouting pipe; 150 - 2# grouting pipe; 160 - 3# grouting pipe; 170 - filling support frame. DETAILED DESCRIPTION

[0028] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0030] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0031] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0032] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0033] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0034] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate the orientation or position relationship based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the embodiments of the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0035] During the development of large permanent chambers in mines, if the surrounding rock is poorly stable or passes through a large water-bearing fracture zone, the roof is very likely to collapse over a large area. The height of the collapse is affected by the degree of rock fragmentation and often collapses to several meters or even tens of meters. In severe cases, it will lead to the upper geological structure or existing projects, causing great safety hazards. In the existing technology, the treatment technology for the empty area of ​​the cavern roof is usually mainly grouting and filling. In the area where the water is gushing and bubbling from the roof of the underground chamber, on the one hand, due to the large exposed empty area at the top, the filling body is easy to collapse, and the water environment is easy to change the properties of the filling body, making the filling construction more difficult; on the other hand, the rock at the top of the collapse area is broken and constantly collapses, making it impossible to grout from the bottom, and lacks a stable rock cap, which cannot bear the grouting pressure and is prone to large-scale grouting and leakage.

[0036] In order to solve the technical problems that the existing filling construction of the water gushing and falling area of ​​the underground chamber roof and the grouting construction of the rock-broken roof are difficult to implement, and the construction safety and stability of the chamber roof cannot be guaranteed, the present application provides a staged grouting filling and sealing method for the water gushing and falling area of ​​the underground chamber roof. Through the staged filling and grouting technology, on the one hand, support is provided for the unstable rock of the roof, and the broken rock mass is connected as a whole to form a complete stress arch; on the other hand, the construction of the filling grouting pipe and the drill hole are combined to grout the water-bearing fracture zone, the water outlet is blocked and the broken rock mass in the deep surrounding rock is reinforced, thereby ensuring the stability of the chamber roof, blocking and reducing water gushing, and helping to improve the comfort and safety of the working environment of personnel and equipment in the underground chamber.

[0037] For the convenience of explanation, the following embodiments are described by taking a method for sealing a water gushing area in a underground chamber roof according to an embodiment of the present application as an example.

[0038] Please refer to Figure 1 In a first aspect, the present application provides a method for sealing a water gushing area of ​​a underground chamber roof by grouting and filling in stages, comprising the following steps:

[0039] S1. Referring to the design outline of the underground chamber with a water gushing area at the top, the chamber roof is constructed and filled with a support frame 170, and the junction between the chamber 100 and the empty area of ​​the top gushing area is sealed with a wooden formwork;

[0040] S2, the 1# grouting pipe 140, the 2# grouting pipe 150 and the 3# grouting pipe 160 are buried in increasing depth from the chamber, and the lower ends of the 1# grouting pipe 140, the 2# grouting pipe 151 and the 3# grouting pipe 160 are all fixed on the filling support frame 170;

[0041] S3, the first stage high-strength concrete filling 110 is carried out from the 1# grouting pipe 140, and the 2# grouting pipe 150 is used as an overflow pipe, and the first stage high-strength concrete filling 110 is stopped after the grouting comes out from the 2# grouting pipe 150;

[0042] S4, after the first stage high-strength concrete of step S3 is initially set, the second stage cement mortar filling 120 is carried out from the 2# grouting pipe 150, and the 3# grouting pipe 160 is used as an overflow pipe, and the second stage cement mortar filling 120 is stopped after the grouting of the 3# grouting pipe 160 is discharged;

[0043] S5. Arrange curtain drilling from a stable location in the chamber or surrounding tunnels to the water-bearing fracture zone above the roof caving area; after the first-stage high-strength concrete in step S3 and the second-stage cement mortar curing in step S4 are completed, perform the third-stage double-liquid grouting 130 from the 3# grouting pipe 160, using the curtain drilling as an exhaust hole, and stop the third-stage double-liquid grouting 130 until slurry flows out of the curtain drilling, thus completing the staged grouting filling and sealing of the water gushing area of ​​the underground chamber roof.

[0044] In the technical solution of this embodiment, in order to solve the problem of large-scale roof collapse caused by crossing large water-bearing fracture zones during the development of large permanent mine chambers, a first-stage high-strength concrete filling 110 is used to form a concrete support structure and provide a stable force-bearing foundation for the next step of filling. The second-stage cement mortar filling 120 is used to basically seal the empty area to form a stable filling body, which is bonded with the surrounding rock to form an overall load-bearing structure to prevent further collapse of the roof. The third-stage double-liquid grouting 130 is used to seal the fault water-bearing fracture zone and bond the broken rock mass as a whole, thereby reinforcing the surrounding rock while blocking water. In this way, the staged grouting and filling sealing method for underground chamber roof collapse areas solves the technical problems that the existing underground chamber roof collapse area filling construction and rock mass broken roof grouting construction are difficult to achieve, and the construction safety and stability of the chamber roof cannot be guaranteed.

[0045] Further, in some embodiments, in step S2, the 1# grouting pipe 140 is buried at the lower edge of the chamber arch foot, and the 1# grouting pipe 140 is arranged horizontally; the 2# grouting pipe 150 is buried at the highest point of the chamber arch, and the 2# grouting pipe 150 is arranged vertically; the 3# grouting pipe 160 is buried in the arch, and its upper opening extends to the lowest point of the top crack of the caving area. The length of the 1# grouting pipe 140 is 0.4 to 0.6m, the upper opening of the 2# grouting pipe 150 is buried 0.4 to 0.6m above the highest point of the chamber arch, and a pressure gauge is installed at the inlet (lower opening) of the 3# grouting pipe 160.

[0046] In the technical solution of the embodiment of the present application, by reasonably designing the size, position and function of the grouting pipes in different stages, the previous construction stage can provide good support for the next construction stage, so that the top plate in each stage is always in a safe and reliable state, avoiding personnel working in the falling area, ensuring the safety of construction personnel, and preventing roof falls and object impact accidents.

[0047] Further, in some embodiments, in step S5, the aperture of the curtain drilling is 80-100 mm, and the number of curtain drilling holes is determined according to the number of fractures in the water-bearing fracture zone development area above the roof caving area, and the ratio of the number of curtain drilling holes to the number of fractures is (2-2.5):1. Before the third stage of double-liquid grouting 130, curtain drilling can be used for early drainage. The curtain drilling is constructed from the chamber or the surrounding tunnel to the water-bearing fracture zone development area above the roof caving area. The main considerations for selecting the opening position include: the rock is stable and complete, the opening position is convenient for drainage, it does not affect the later function of the chamber, and it is as close to the upper part of the roof caving area as possible to reduce the drilling construction workload.

[0048] In the technical solution of the embodiment of the present application, curtain drilling is arranged in the area where water-bearing fracture zones are developed above the caving area, which plays the role of cutting off part of the water source. While providing exhaust holes for grouting, it can also drain water in advance to prevent a large amount of fracture water from reducing the concentration of the grouting body and causing slurry leakage, thereby improving the grouting effect.

[0049] Further, in some embodiments, in step S5, in the third stage of double-liquid grouting 130, the final grouting pressure is 2 to 2.5 times the hydrostatic pressure. If the hydrostatic pressure is less than 4 MPa, 8 to 10 MPa is used as the final grouting pressure. The curing time of the first stage high-strength concrete and the second stage cement mortar is 8 to 12 days.

[0050] In the technical solution of the embodiment of the present application, the final pressure of the third stage dual-liquid grouting 130 is limited to ensure that the grouting achieves the expected effect, the curtain drilling hole is used as the exhaust hole, and the outflow of a small amount of slurry from the exhaust hole is used as the visual critical point for the end of grouting, thereby ensuring the effect of grouting to seal cracks.

[0051] Furthermore, in some embodiments, in the first stage high-strength concrete filling 110, concrete with a strength of C40 or above is used, in the second stage cement mortar filling 120, cement mortar with a strength of C20 is used, and in the third stage double-liquid grouting 130, the grouting material is a double-liquid slurry of cement and water glass. The specific proportions of each material can be adjusted according to the specific conditions on site.

[0052] In the technical solution of the embodiment of the present application, by limiting the raw materials for filling and grouting in different stages, the previous construction process can provide good support for the next construction process, so that the roof is always in a safe and reliable state during the construction of each stage; in addition, the method of filling and grouting in stages, through the determination of the visible critical point of construction, determines the stage of construction based on the actual engineering phenomena on site, and uses it as the basis for determining the next step of construction, thereby achieving accurate grasp of the construction time and construction steps, and providing a practical and effective method for the treatment of caving areas in large underground chambers.

[0053] Furthermore, in some embodiments, in step S2, the diameters of the 1# grouting pipe 140, the 2# grouting pipe 150 and the 3# grouting pipe 160 are 80-100 mm.

[0054] Furthermore, in some embodiments, in step S1, the filling support frame 170 is prepared according to the specification and shape of the chamber 100, and is composed of a plurality of U-shaped steel arch beams and a plurality of fixed cross beams.

[0055] In the technical solution of the embodiment of the present application, U-shaped steel arch beams and cross beams are manufactured according to the specifications and shape of the chamber as the filling support skeleton 170. On the one hand, a reliable fixed end is provided for the burial of the grouting filling pipe, so that the grouting filling pipe can be fixed to the corresponding position according to the needs of the phased construction; on the other hand, basic support is provided for the poor roof, and at the same time, a reliable boundary constraint is provided for the formation of an artificial false roof during the first stage of filling, thereby reducing the risk of large-scale collapse of the roof.

[0056] Some specific embodiments are listed below. It should be noted that the embodiments described below are exemplary and are only used to explain the present application, and should not be construed as limiting the present application. If specific techniques or conditions are not specified in the embodiments, the techniques or conditions described in the literature in this area or the product specifications are used. The reagents or instruments used without specifying the manufacturer are all conventional products that can be obtained commercially.

[0057] Example 1

[0058] A blind shaft of a gold mine is in the development period of measures engineering. Its sheave chamber is connected to the stable car chamber, which is a super-large key chamber. The rocks in the area are extremely broken, a large number of fault joints are developed, and the structural dip angle is about 80°, which almost runs through all the main shaft drilling measures engineering. In addition, the hydrological conditions in the area are complex, the water content of the structural fissures is large, and the hydrostatic pressure in some areas is large. The total water volume exposed is about 200m 3 / h. During the construction of the stable vehicle chamber pilot tunnel, a large area of ​​the chamber collapsed, with the collapse height reaching 18m. The chamber was shut down for treatment. A large amount of pressurized fissure water was seen gushing out on site, and the collapse height continued to increase.

[0059] Since the rock in the roof-falling area is extremely broken and it is impossible to enter the site for support operations, in order to prevent the falling zone from continuing to develop along the fault, resulting in a large empty area on the roof of the sheave chamber; according to the on-site environment and water discharge conditions, this embodiment provides a staged grouting and filling sealing method for the water-gushing and falling area of ​​the roof of an underground chamber, including the following steps:

[0060] S1. Construction: Prepare the chamber roof filling support frame consisting of several U-shaped steel arch beams and several fixed cross beams according to the specifications and shapes of the chamber, and use wooden formwork to seal the junction between the chamber and the roof caving area;

[0061] S2, 1# grouting pipe, 2# grouting pipe and 3# grouting pipe with increasing buried depth from the chamber, the lower ends of 1# grouting pipe, 2# grouting pipe and 3# grouting pipe are all fixed on the filling support frame;

[0062] Among them, the 1# grouting pipe is buried at the lower edge of the chamber arch foot, with a length of 0.5m, and the 1# grouting pipe is arranged horizontally; the 2# grouting pipe is buried at the highest point of the chamber arch, arranged vertically, and the upper end of the 2# grouting pipe is buried 0.5m higher than the highest point of the chamber arch; the 3# grouting pipe is buried in the arch, and its upper end extends to the lowest point of the top crack of the caving area. A pressure gauge is installed at the inlet (lower end) of the 3# grouting pipe; the diameters of the 1# grouting pipe, 2# grouting pipe and 3# grouting pipe are 90mm;

[0063] S3, the first stage of high-strength concrete filling (using concrete with strength of C40 or above) is carried out from the 1# grouting pipe, and the 2# grouting pipe is used as an overflow pipe. The first stage of high-strength concrete filling is stopped after the grouting pipe 2# grouting pipe is discharged;

[0064] S4, after the first stage high-strength concrete of step S3 is initially set, the second stage cement mortar filling (using cement mortar with strength C20) is carried out from the 2# grouting pipe, and the 3# grouting pipe is used as an overflow pipe. The second stage cement mortar filling is stopped after the 3# grouting pipe discharges slurry;

[0065] S5. Arrange curtain drilling holes from the stable location of the chamber or surrounding tunnels to the water-bearing fracture zone above the roof caving area. The diameter of the curtain drilling holes is 90 mm, and the number of curtain drilling holes is 4. Before the third-stage double-liquid grouting, use curtain drilling to drain water in advance. After the first-stage high-strength concrete of step S3 and the second-stage cement mortar of step S4 have been cured for 10 days, the third-stage double-liquid grouting (the grouting material is a double-liquid slurry of cement and water glass) is carried out from the 3# grouting pipe, with 10 MPa as the final grouting pressure, and the curtain drilling holes are used as exhaust holes. When slurry flows out of the curtain drilling holes, the third-stage double-liquid grouting is stopped, and the staged grouting, filling and sealing of the water gushing area of ​​the roof of the underground chamber of the blind shaft of the gold mine are completed.

[0066] Through the staged grouting filling and sealing method of Example 1, the roof collapse and broken area of ​​the blind shaft of the gold mine is controlled, the roof of the chamber is stabilized, a complete stress arch is formed, and the safety hazard of water flowing into the shaft is eliminated, preventing it from causing adverse effects on the equipment in the sheave chamber, so that subsequent development construction can be carried out.

[0067] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are only examples, and the embodiments having the same structure as the technical idea and exerting the same effect within the scope of the technical solution of the present application are all included in the technical scope of the present application. In addition, without departing from the scope of the main purpose of the present application, various modifications that can be thought of by those skilled in the art to the embodiments and other methods of combining some of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. A method for sealing the water gushing and falling area of ​​the underground chamber roof by grouting and filling in stages, characterized in that: The following steps are involved: S1. Refer to the design outline of the chamber, construct and fill the supporting frame on the chamber roof, and use wooden formwork to seal the junction between the chamber and the empty area of ​​the roof; S2, 1# grouting pipe, 2# grouting pipe and 3# grouting pipe with increasing buried depth from the chamber, the lower openings of the 1# grouting pipe, 2# grouting pipe and 3# grouting pipe are all fixed on the filling support frame; S3, filling the first stage of high-strength concrete from the 1# grouting pipe, using the 2# grouting pipe as an overflow pipe, and stopping the first stage of high-strength concrete filling after the grouting from the 2# grouting pipe is discharged; S4, after the first stage high-strength concrete of step S3 is initially set, the second stage cement mortar filling is carried out from the 2# grouting pipe, and the 3# grouting pipe is used as an overflow pipe, and the second stage cement mortar filling is stopped after the 3# grouting pipe discharges slurry; S5. Arrange curtain drillings from a stable location in the chamber or surrounding tunnels to the water-bearing fracture zone above the roof caving area; after the curing of the first-stage high-strength concrete in step S3 and the second-stage cement mortar in step S4 is completed, perform the third-stage double-liquid grouting from the 3# grouting pipe, using the curtain drillings as exhaust holes, and stop the third-stage double-liquid grouting until slurry flows out of the curtain drillings, thus completing the staged grouting, filling and sealing of the water gushing area of ​​the underground chamber roof.

2. The method for sealing the water gushing and falling area of ​​the underground chamber roof according to claim 1 is characterized in that: In step S2, the 1# grouting pipe is buried at the lower edge of the chamber arch foot, and the 1# grouting pipe is arranged horizontally; the 2# grouting pipe is buried at the highest point of the chamber arch, and the 2# grouting pipe is arranged vertically; the 3# grouting pipe is buried in the arch, and its upper mouth extends to the lowest point of the top crack of the caving area.

3. The method for sealing the water gushing and falling area of ​​the underground chamber roof according to claim 2 is characterized in that: The length of the 1# grouting pipe is 0.4-0.6m, the upper opening of the 2# grouting pipe is buried at a height that exceeds the highest point of the chamber vault by 0.4-0.6m, and a pressure gauge is installed at the inlet position of the 3# grouting pipe.

4. The method for sealing the water gushing and falling area of ​​the underground chamber roof according to claim 1 is characterized in that: In step S5, the aperture of the curtain drilling hole is 80-100 mm, and the number of the curtain drilling holes is determined according to the number of fractures in the water-bearing fracture zone above the caving zone. The ratio of the number of the curtain drilling holes to the number of fractures is (2-2.5):

1.

5. The method for sealing the underground chamber roof water gushing and falling area by staged grouting and filling according to claim 1 is characterized in that: In step S5, in the third stage of double-liquid grouting, the final grouting pressure is 2 to 2.5 times the hydrostatic pressure. If the hydrostatic pressure is less than 4 MPa, 8 to 10 MPa is used as the final grouting pressure.

6. The method for sealing the water gushing and falling area of ​​the underground chamber roof according to claim 1 is characterized in that: In the first stage of high-strength concrete filling, concrete with a strength of C40 or above is used, in the second stage of cement mortar filling, cement mortar with a strength of C20 is used, and in the third stage of double-liquid grouting, the grouting material is a double-liquid slurry of cement and water glass.

7. The method for sealing the water gushing and falling area of ​​the underground chamber roof according to claim 1 is characterized in that: In step S5, before the third stage of dual-liquid grouting, the curtain drilling may be used to perform early drainage.

8. The method for sealing the water gushing and falling area of ​​the underground chamber roof according to claim 1 is characterized in that: In step S2, the diameters of the 1# grouting pipe, the 2# grouting pipe and the 3# grouting pipe are 80-100 mm.

9. The method for sealing the water gushing and falling area of ​​the underground chamber roof according to claim 1, characterized in that: In step S1, the filling support frame is prepared according to the specification and shape of the chamber, and is composed of a plurality of U-shaped steel arch beams and a plurality of fixed cross beams.

10. The method for sealing the water gushing and falling area of ​​the underground chamber roof according to claim 1, characterized in that: In step S5, the curing time of the first-stage high-strength concrete and the second-stage cement mortar is 8 to 12 days.

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