Method for sealing by staged grouting and filling of water gushing and caving area of roof of underground chamber

Abstract

The application provides a method for grading grouting filling and sealing of a water gushing and roof falling area of a downhole chamber, and belongs to the field of roof falling area treatment of a downhole chamber. The method comprises the following steps: first, constructing a filling support framework of the roof of the chamber, and sealing the joint position of the chamber and the roof falling empty area by using a wooden formwork; second, according to a reasonable design, embedding grouting pipes of different stages; third, sequentially performing first-stage high-strength concrete filling, second-stage cement mortar filling and third-stage double-liquid slurry grouting. The application provides support for unstable roof rock by using the grading filling grouting technology, connects the broken rock mass into a whole, forms a complete stress arch, and combines the construction filling grouting pipe and the borehole to perform grouting on the water-bearing fractured zone, thereby plugging the water outlet and reinforcing the broken rock mass in the deep surrounding rock, so as to ensure the stability of the roof of the chamber, reduce the water gushing and falling, and improve the comfort and safety of the working environment of personnel and equipment in the downhole chamber.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of roof caving area treatment of underground chamber, and particularly relates to a method for treating roof caving area of underground chamber by staged grouting and filling. BACKGROUND

[0002] In the process of developing large permanent chamber in a mine, if the surrounding rock stability is poor or a large water-bearing fracture zone is passed through, the roof is prone to large-area caving, and the caving height is often collapsed to several meters or even tens of meters due to the degree of rock fragmentation, and in severe cases, it can lead to the connection of the upper geological structure or the existing engineering, causing great safety hazards. The treatment of the roof caving area of the underground chamber needs to consider not affecting the original function of the chamber and ensuring the safety of the chamber roof. If in the complex hydrogeological conditions with rich water, the treatment difficulty of the empty area will be further increased.

[0003] In the prior art, the treatment technology for the chamber roof caving area is usually mainly two ways of grouting and filling. Among them, the filling technology is usually used for the construction of the internal empty area of the small rock mass on the side or the exposed opening, and it is difficult to solve the problem of the roof treatment and the large caving area with large exposed area by the traditional filling construction method. The main function of the existing grouting construction process is to reinforce the rock mass and control water gushing, but it is greatly restricted by the operation site, and when reinforcing the rock mass, it often needs 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 spatial gap distribution of the caving area, which achieves the treatment of the caving area by arranging long grouting holes at a long distance and carrying out three-dimensional grouting. However, when controlling water gushing by grouting, the top rock needs to be relatively complete and can withstand enough grouting pressure. In the roof water gushing and caving area 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, resulting in difficult filling construction; on the other hand, the rock at the top of the caving area is broken and constantly collapses, and it is impossible to grout from the bottom, and there is no stable cap rock to bear the grouting pressure, which is easy to cause a large amount of grouting and grouting leakage.

[0004] Therefore, it is necessary to develop a method for treating the roof caving area of the underground chamber to overcome the difficulties of filling construction in the water and roof caving area and grouting construction in the broken rock roof, solve the problem of treating the roof water gushing and caving area of the underground chamber, and ensure the safety of the construction and the safety and stability of the chamber roof. SUMMARY

[0005] In view of the technical problems in the background art, the present application provides a method for treating the roof water gushing and caving area of the underground chamber by staged grouting and filling, which aims to solve the technical problems that the filling construction in the water and roof caving area and the grouting construction in the broken rock roof are difficult to implement, and the construction safety and the stability of the chamber roof cannot be guaranteed.

[0006] In a first aspect, the embodiments of the present application provide a method for phased grouting and filling sealing of a water gushing and roof falling area of a downhole chamber, characterized in that the method comprises the following steps:

[0007] S1. Referring to the design contour of the chamber, a filling support framework is constructed on the roof of the chamber, and a wooden template is used to close the junction position between the chamber and the roof falling cavity;

[0008] S2. A 1# grouting pipe, a 2# grouting pipe and a 3# grouting pipe are sequentially embedded from the buried depth of the chamber, and the lower openings of the 1# grouting pipe, the 2# grouting pipe and the 3# grouting pipe are fixed on the filling support framework;

[0009] S3. First stage high-strength concrete filling is performed from the 1# grouting pipe, the 2# grouting pipe is used as an overflow pipe, and after the 2# grouting pipe discharges grout, the first stage high-strength concrete filling is stopped;

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

[0011] S5. Curtain drill holes are arranged from the chamber or a stable site around the roadway to the water-bearing fracture zone above the roof falling cavity; after the first stage high-strength concrete of step S3 and the second stage cement mortar of step S4 are cured, third stage double-liquid slurry grouting is performed from the 3# grouting pipe, the curtain drill holes are used as exhaust holes, and after the curtain drill holes discharge slurry, the third stage double-liquid slurry grouting is stopped, and the phased grouting and filling sealing of the water gushing and roof falling area of the downhole chamber is completed.

[0012] In the technical scheme of the embodiment of the application, in view of the problem of large-area roof caving caused by passing through a large water-bearing fracture zone in the development process of a large permanent chamber in a mine, a first-stage high-strength concrete filling is used to form a whole structure of concrete support and provide a stable stress foundation for the next filling, a second-stage cement mortar filling is used to basically seal the empty area and form a stable filling body, which is cemented with surrounding rock to form a whole stress structure, thereby preventing the roof from further caving, and a third-stage double-liquid slurry grouting is used to seal the fault water-bearing fracture zone and cement the broken rock mass into a whole, thereby reinforcing the surrounding rock while plugging water. Through the stage-by-stage filling and grouting technology, on the one hand, the unstable rock of the roof is supported and the broken rock mass is connected into a whole to form a complete stress arch, and on the other hand, the construction filling and grouting pipe and the borehole are combined to grout the water-bearing fracture zone, thereby plugging the water outlet and reinforcing the broken rock mass in the deep surrounding rock, so as to ensure the stability of the roof of the chamber and reduce the gushing water, which helps to improve the comfort and safety of the working environment of personnel and equipment in the chamber.

[0013] In some embodiments, in step S2, the 1# grouting pipe is buried at the lower edge of the arch foot of the chamber, and the 1# grouting pipe is horizontally arranged; the 2# grouting pipe is buried at the highest point of the chamber vault, and the 2# grouting pipe is vertically arranged; and the 3# grouting pipe is buried at the vault, and the upper opening of the 3# grouting pipe extends to the top fracture lowest point of the roof caving empty area. The length of the 1# grouting pipe is 0.4-0.6 m, the upper opening of the 2# grouting pipe is buried at a height exceeding the highest point of the chamber vault by 0.4-0.6 m, and the inlet (lower opening) of the 3# grouting pipe is provided with a pressure gauge.

[0014] In the embodiment, by reasonably designing the size, position and function of the grouting pipes in different stages, the previous construction stage provides good support for the next construction stage, the roof in each stage is always in a safe and reliable state, the personnel working in the caving area is avoided, the safety of the construction personnel is ensured, and the occurrence of roof caving accidents and object impact accidents is prevented.

[0015] In some embodiments, in step S5, the aperture of the curtain borehole is 80-100 mm, the number of the curtain boreholes is determined according to the number of fractures in the water-bearing fracture zone development area above the roof caving empty area, and the number ratio of the curtain boreholes to the fractures is (2-2.5):1. Before the third-stage double-liquid slurry grouting, the curtain boreholes can be used for pre-drainage. The curtain borehole is constructed from the chamber or the surrounding roadway to the water-bearing fracture zone development area above the roof caving empty area, and the main factors for selecting the opening position of the curtain borehole include: stable and complete rock, convenient drainage at the opening position, no influence on the later function of the chamber, and close to the upper part of the roof caving area to reduce the drilling construction engineering quantity.

[0016] In this embodiment, curtain drill holes are arranged above the water-bearing fractured zone development area in the caving area, which plays a role in cutting off part of the water source, provides an exhaust hole for grouting, and can drain water in advance to prevent a large amount of fissure water from reducing the concentration of the grouting body to cause grouting to run, and improve the grouting effect.

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

[0018] In this embodiment, by limiting the final pressure of the third stage double-liquid slurry grouting, the grouting achieves the expected effect, the curtain drill hole is used as an exhaust hole, and a small amount of slurry flowing out of the exhaust hole is used as a visible critical point for the end of grouting, which ensures the effect of grouting to seal the fissures.

[0019] In some embodiments, in the first stage high-strength concrete filling, concrete with a strength of C40 or above is used, in the second stage cement mortar filling, cement mortar with a strength of C20 is used, and in the third stage double-liquid slurry 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 construction. In addition, by determining the construction visible critical point, the actual engineering phenomenon is used to determine the stage of construction, which is used as a basis for determining the next step of construction, so that the construction time and steps are accurately grasped, and a practical and effective method is provided for the management of the caving area of the large underground chamber.

[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 framework is prepared according to the size and shape of the chamber and is composed of several U-shaped steel arch beams and several fixed cross beams.

[0023] In this embodiment, by making U-shaped steel arch beams and fixed cross beams according to the size and shape of the chamber as the filling support framework, on the one hand, it provides a reliable fixed end for the embedding of the grouting filling pipe, so that the grouting filling pipe can be fixed to the corresponding position according to the needs of the staged construction; on the other hand, it provides basic support for the poor roof and reliable boundary constraints for the artificial false roof formed by one-stage filling, which reduces the risk of large-area roof caving.

[0024] The above description is only a summary of the technical solutions of the present application. In order to make the technical means of the present application more clearly understood and can be implemented according to the content of the specification, and in order to make the above and other purposes, characteristics and advantages of the present application more obvious and easy to understand, the following specific embodiments of the present application are described. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the present application, the drawings used in the present application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0026] Figure 1 The schematic diagram of the method for staged grouting and filling sealing of the roof water gushing and caving area of the underground chamber in the embodiment of the present application;

[0027] The drawings are explained as follows: 100-chamber; 110-first stage high-strength concrete filling; 120-second stage cement mortar filling; 130-third stage double-liquid slurry grouting; 140-1# grouting pipe; 150-2# grouting pipe; 160-3# grouting pipe; 170-filling support framework. DETAILED DESCRIPTION

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

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present application; the terms "include" and "have" and any variations thereof in the specification and claims of the present application and the above drawing description, are intended to cover non-exclusive inclusion.

[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 "a plurality of" is two or more, unless otherwise explicitly specified.

[0031] Reference to“an embodiment” herein means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase“in an embodiment” in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily all referring to a common set of embodiments, of the application. It will be apparent to those skilled in the art that the embodiments described herein can be combined with other embodiments in various ways.

[0032] In the description of the embodiments of the application, the term“and / or” only means an association relationship of the associated objects, which can represent three relationships, for example, A and / or B, which can represent three cases of A existing alone, A and B existing together, and B existing alone. In addition, the character“ / ” herein generally represents that the front and rear associated objects have an“or” relationship.

[0033] In the description of the embodiments of the application, the term“a plurality of” refers to two or more (including two), and similarly, “a plurality of groups” refers to two or more groups (including two groups), and “a plurality of pieces” refers to two or more pieces (including two pieces).

[0034] In the description of the embodiments of the application, the technical terms“center”,“longitudinal”,“transverse”,“length”,“width”,“thickness”,“upper”,“lower”,“front”,“rear”,“left”,“right”,“vertical”,“horizontal”,“top”,“bottom”,“inner”,“outer”,“clockwise”,“counterclockwise”,“axial”,“radial”,“circumferential” and the like indicate the orientation or positional relationship shown in the drawings, which are only for the convenience of describing the embodiments of the application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the embodiments of the application. For those skilled in the art, the specific meanings of the above terms in the embodiments of the application can be understood according to the specific circumstances.

[0035] In the development process of large permanent chambers in mines, if the surrounding rock stability is poor or a larger water-bearing fracture zone is crossed, the roof is prone to large-area caving, and the caving height is often collapsed to several meters or even tens of meters due to the influence of the degree of rock fragmentation, and in severe cases, it can lead to the connection of the upper geological structure or the existing engineering, causing great safety hazards. In the prior art, the treatment technology for the chamber roof caving area is usually mainly two ways of grouting and filling. In the roof caving area 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 leaching environment is easy to change the properties of the filling body, resulting in difficult filling construction; on the other hand, the rock at the top of the caving area is broken and constantly collapses, cannot be grouted from the bottom, and lacks a stable cap to bear the grouting pressure, which is easy to run and leak a large amount of grout.

[0036] In order to solve the technical problems that the filling construction of the water gushing and roof falling area of the underground chamber roof is difficult to be realized, the grouting construction of the broken roof is difficult to be realized, the construction safety and the stability of the chamber roof cannot be ensured, the underground chamber roof water gushing and roof falling area phased grouting filling sealing method is provided, through the phased filling grouting technology, on the one hand, the unstable roof rock is supported, and the broken rock mass is connected as a whole, and a complete stress arch is formed, on the other hand, the construction filling grouting pipe and the drill hole are combined, the water-bearing fractured zone is grouted, the water outlet point is blocked, and the broken rock mass in the deep surrounding rock is reinforced, so that the stability of the chamber roof is ensured, the water gushing and roof falling area is blocked, the water gushing and roof falling area is reduced, and the comfort and safety of the working environment of the personnel and equipment in the underground chamber are improved.

[0037] The following examples are described by taking the underground chamber roof water gushing and roof falling area phased grouting filling sealing method as an example for convenience of description.

[0038] Please refer to Figure 1 , in a first aspect, the underground chamber roof water gushing and roof falling area phased grouting filling sealing method is provided, and the method comprises the following steps:

[0039] S1, referring to the design contour of the underground chamber with the water gushing and roof falling area at the top, the chamber roof construction filling support framework 170 is constructed, and the wooden formwork is used to seal the junction position of the chamber 100 and the roof falling empty area;

[0040] S2, the 1# grouting pipe 140, the 2# grouting pipe 150 and the 3# grouting pipe 160 with increasing depths are embedded in the chamber, and the lower openings of the 1# grouting pipe 140, the 2# grouting pipe 150 and the 3# grouting pipe 160 are fixed on the filling support framework 170;

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

[0042] S4, after the first stage high-strength concrete in step S3 is initially cured, the second stage cement mortar filling 120 is performed from the 2# grouting pipe 150, the 3# grouting pipe 160 is used as an overflow pipe, and the second stage cement mortar filling 120 is stopped after the 3# grouting pipe 160 discharges the slurry;

[0043] S5, arranging curtain drill holes from the chamber or the surrounding roadway stable site to the water-bearing fracture zone development area above the roof fall empty area; after the first stage high-strength concrete of step S3 and the second stage cement mortar maintenance of step S4 are completed, the third stage double-liquid slurry grouting 130 is performed from the 3# grouting pipe 160, taking the curtain drill hole as an exhaust hole, until the slurry flows out from the curtain drill hole, the third stage double-liquid slurry grouting 130 is stopped, and the phased grouting and filling sealing of the underground chamber roof water inrush and roof fall area is completed.

[0044] In the technical scheme of the embodiment, for the problem of large-area roof fall caused by passing through a large water-bearing fracture zone in the development process of a large permanent chamber in a mine, the first stage high-strength concrete filling 110 is used to form a concrete support overall structure and provide a stable stress foundation for the next filling, the second stage cement mortar filling 120 is used to basically seal the empty area and form a stable filling body, which is cemented with the surrounding rock to form an overall load-bearing structure to prevent further roof fall, and the third stage double-liquid slurry grouting 130 is used to seal the fault water-bearing fracture zone and cement the broken rock mass as a whole to reinforce the surrounding rock while blocking water. In this way, the phased grouting and filling sealing method for the underground chamber roof water inrush and roof fall area solves the technical problems that the existing filling construction and grouting construction for the broken roof are difficult to implement, cannot guarantee the construction safety, and cannot ensure the stability of the chamber roof.

[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 arranged horizontally, the 2# grouting pipe 150 is buried at the highest point of the chamber vault and arranged vertically, and the 3# grouting pipe 160 is buried at the vault and the upper opening thereof extends to the top fracture lowest point of the roof fall empty area. The length of the 1# grouting pipe 140 is 0.4-0.6 m, the upper opening of the 2# grouting pipe 150 is buried 0.4-0.6 m higher than the highest point of the chamber vault, and the inlet (lower opening) of the 3# grouting pipe 160 is provided with a pressure gauge.

[0046] In the technical scheme of the embodiment, by reasonably designing the size, position and function of the grouting pipes in different stages, the previous construction stage provides good support for the next construction stage, the roof is always in a safe and reliable state, personnel working in the falling area is avoided, the safety of construction personnel is ensured, and roof fall accidents and object impact accidents are prevented.

[0047] Further, in some embodiments, in step S5, the curtain borehole has a bore diameter of 80-100 mm, and the number of curtain boreholes is determined according to the number of fissures in the water-bearing fissure zone above the roof-falling empty area, and the ratio of the number of curtain boreholes to the number of fissures is (2-2.5):1. Before the third-stage double-liquid slurry grouting 130, the curtain borehole can be used for pre-drainage. The curtain borehole is constructed from the chamber or the surrounding roadway to the water-bearing fissure zone above the roof-falling empty area, and the main factors for selecting the opening position include: stable and complete rock, convenient drainage at the opening position, no influence on the later function of the chamber, and close to the upper part of the roof-falling area to reduce the engineering quantity of drilling.

[0048] In the technical scheme of the embodiments of the present application, the curtain borehole is arranged in the water-bearing fissure zone above the roof-falling area, which plays a role in cutting off part of the water source, provides an air vent for grouting, and can pre-drainage to prevent a large amount of fissure water from reducing the concentration of the grouting body and causing slurry running, thereby improving the grouting effect.

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

[0050] In the technical scheme of the embodiments of the present application, by limiting the final pressure of the third-stage double-liquid slurry grouting 130, the grouting achieves the expected effect, the curtain borehole is used as an air vent, a small amount of slurry flowing out of the air vent is used as a visible critical point for ending grouting, and the effect of grouting to seal fissures is ensured.

[0051] Further, 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 slurry grouting 130, the grouting material is double-liquid slurry of cement and water glass, and the specific material ratio can be adjusted according to the specific situation on site.

[0052] In the technical scheme of the embodiments 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 construction in each stage. In addition, by determining the construction visible critical point, the actual engineering phenomenon on site is used to determine the stage of construction, which is used as a basis for determining the next step of construction, so that the construction time and steps are accurately grasped, and a practical and effective method for managing the roof-falling area of a large underground chamber is provided.

[0053] Further, 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] Further, in some embodiments, in step S1, the filling support framework 170 is prepared according to the size 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 scheme of the embodiments of the present application, the U-shaped steel arch beams and cross beams are made according to the size and shape of the chamber to serve as the filling support framework 170, which on the one hand provides a reliable fixed end for the embedding of the grouting filling pipe, so that the grouting filling pipe can be fixed to the corresponding position according to the needs of the staged construction; on the other hand, it provides basic support for the poor roof and reliable boundary constraint for the artificial false roof formed by one-stage filling, thereby reducing the risk of large-area roof caving.

[0056] Some specific embodiments are listed below. It should be noted that the embodiments described below are exemplary and are used to explain the present application, and cannot be understood as a limitation of the present application. If a specific technology or condition is not specified in the embodiments, it is performed according to the technology or condition described in the literature in the art or according to the product manual. If the reagent or instrument used is not specified by the manufacturer, it is a conventional product that can be obtained from the market.

[0057] Embodiment 1

[0058] A blind well of a certain gold mine is in the development period of the support project, and the crown chamber and the stable car chamber are connected, which belongs to a super-large key chamber. The rock in the area is extremely broken, a large number of faults and joints are developed, the structural dip angle is about 80°, and it almost penetrates all the main shaft sinking support projects. Moreover, the hydrological conditions in this area are complex, the structural fracture water content is large, the static water pressure in some areas is large, and the total water yield is about 200 m 3 / h. When the stable car chamber guide chamber is constructed, a large area of the chamber caved, with a caving height of 18 m. The chamber was stopped for treatment, and a large amount of confined fissure water was seen to gush out, and the caving height continued to increase.

[0059] Based on the fact that the rock in the caving area is extremely broken and cannot be accessed for support operations, in order to prevent the caving zone from continuing to develop along the fault and causing a large empty area in the roof of the crown chamber, and in view of the site environment and water outflow, the present embodiment provides a method for staged grouting and filling sealing of the roof water gushing and caving area in the underground chamber, which comprises the following steps:

[0060] S1, a chamber roof filling support framework composed of a plurality of U-shaped steel arch beams and a plurality of fixed cross beams is prepared according to the size and shape of the chamber, and a wooden formwork is used to close the junction between the chamber and the caving empty area;

[0061] S2, 1# grouting pipe, 2# grouting pipe and 3# grouting pipe with increasing buried depth in the chamber, the lower opening of 1# grouting pipe, 2# grouting pipe and 3# grouting pipe are fixed on the filling support framework;

[0062] Wherein, 1# grouting pipe is buried at the lower edge of the chamber arch foot, the length is 0.5m, 1# grouting pipe is horizontally arranged; 2# grouting pipe is vertically arranged and buried at the highest point of the chamber vault, the upper opening of 2# grouting pipe is buried 0.5m higher than the highest point of the chamber vault; 3# grouting pipe is buried at the vault, the upper opening of 3# grouting pipe extends to the top fracture lowest point of the roof fall area, the inlet (lower opening) of 3# grouting pipe is installed with a pressure gauge; the diameter of 1# grouting pipe, 2# grouting pipe and 3# grouting pipe is 90mm;

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

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

[0065] S5, curtain drill holes are arranged from the chamber or the stable site of surrounding roadway to the development area of water-bearing fracture zone above the roof fall area, the diameter of the curtain drill holes is 90mm, and the number of the curtain drill holes is 4; before the third stage double liquid slurry grouting, the curtain drill holes are used for pre-drainage; after the first stage high strength concrete of step S3 and the second stage cement mortar of step S4 are cured for 10 days, third stage double liquid slurry grouting (double liquid slurry of cement and water glass is used as grouting material) is carried out from 3# grouting pipe, 10MPa is used as final grouting pressure, the curtain drill holes are used as exhaust holes, and the third stage double liquid slurry grouting is stopped when the slurry flows out of the curtain drill holes, and the phased grouting filling and sealing of the roof water inrush and roof fall area of the underground chamber of the blind well of the gold mine is completed.

[0066] Through the phased grouting filling and sealing method of example 1, the roof fall broken area of the blind well of the gold mine is treated, the chamber roof is stable, a complete stress arch is formed, and the safety hidden danger of water flow into the shaft is eliminated, which prevents the adverse effects on the equipment in the chamber, and the subsequent development construction can be carried out.

[0067] Note that the present application is not limited to the above-described embodiments. The above-described embodiments are merely examples, and embodiments having substantially the same configuration, function, and effect as the technical idea of the present application are included in the technical scope of the present application. Furthermore, other modes constructed by applying various modifications to the embodiments, or by combining part of the configurations of the embodiments, which can be conceived by those skilled in the art, without departing from the spirit of the present application, are also included in the scope of the present application.

Claims

1. A method for phased grouting and filling sealing of water gushing and caving area of underground chamber roof, characterized in that, The method comprises the following steps: S1, referring to the chamber design profile, constructing a filling support framework on the chamber roof, and using a wooden template to close the junction position of the chamber and the roof fall empty area; S2, embedding a 1# grouting pipe, a 2# grouting pipe and a 3# grouting pipe in the chamber in sequence, the lower openings of the 1# grouting pipe, the 2# grouting pipe and the 3# grouting pipe are fixed on the filling support framework; S3, carrying out first stage high-strength concrete filling from the 1# grouting pipe, taking the 2# grouting pipe as an overflow pipe, and stopping the first stage high-strength concrete filling after the 2# grouting pipe discharges slurry; S4, after the first stage high-strength concrete in step S3 is initially cured, carrying out second stage cement mortar filling from the 2# grouting pipe, taking the 3# grouting pipe as an overflow pipe, and stopping the second stage cement mortar filling after the 3# grouting pipe discharges slurry; S5, arranging curtain drill holes from the chamber or a stable site of the surrounding roadway to the water-bearing fracture zone above the roof fall empty area; after the first stage high-strength concrete in step S3 and the second stage cement mortar in step S4 are cured, carrying out third stage double-liquid slurry grouting from the 3# grouting pipe, taking the curtain drill holes as exhaust holes, and stopping the third stage double-liquid slurry grouting after the curtain drill holes discharge slurry, thereby completing the phased grouting filling and sealing of the underground chamber roof water inrush and roof fall area.

2. The method for phased grouting and filling sealing of water gushing and caving area of roof of underground chamber according to claim 1, characterized in that, In step S2, the 1# grouting pipe is embedded at the lower edge of the chamber arch foot, and the 1# grouting pipe is horizontally arranged; the 2# grouting pipe is embedded at the highest point of the chamber vault, and the 2# grouting pipe is vertically arranged; and the 3# grouting pipe is embedded at the vault, and the upper opening of the 3# grouting pipe extends to the top fracture lowest point of the roof fall empty area.

3. The method according to claim 2, wherein, The length of the 1# grouting pipe is 0.4-0.6 m, the upper opening of the 2# grouting pipe is embedded at a height exceeding the highest point of the chamber vault by 0.4-0.6 m, and a pressure gauge is installed at the inlet position of the 3# grouting pipe.

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

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

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

7. The method for phased grouting and filling sealing of water gushing and caving area of roof of underground chamber according to claim 1, characterized in that, In step S5, before the third stage double-liquid slurry grouting, the curtain drill holes can be used for pre-drainage.

8. The method for phased grouting and filling sealing of water gushing and caving area of roof of underground chamber according to claim 1, 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 phased grouting and filling sealing of water gushing and caving area of roof of underground chamber according to claim 1, characterized in that, In step S1, the filling support framework is prepared according to the size 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 phased grouting and filling sealing of water gushing and caving area of roof of underground chamber 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 8-12 days.

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