Method for protecting roadway through cooperation of roadside filling body and roof grouting

Abstract

The invention discloses a roadway-side filling body and roof grouting collaborative roadway protection method, which comprises the following steps: drilling a fracture surrounding rock on one side of a goaf along the roadway direction to obtain a roof drill hole, arranging a roadway-side filling wall structure below the roof drill hole, filling gangue in the roof drill hole, and grouting the roof drill hole and the inside of the roadway-side filling wall structure respectively, after the slurry in the roadside filling wall body structure is solidified, a roadside filling body is formed, and finally the roadside filling wall body structure is dismantled, so that the supporting advantages of roof grouting and roadside filling are jointly exerted, roof damage caused by surrounding rock and water-rich rock strata is effectively controlled, the overall stability of a roadway is remarkably improved, and the construction cost is reduced. And disasters such as water inrush and roof caving of the roadway roof are prevented, and the method is suitable for supporting high-risk roadways in weak surrounding rock and water-rich areas.

Description

Technical Field

[0001] The present application relates to the technical field related to mining engineering, and in particular to a method for collaboratively protecting a tunnel by using a tunnel side filling body and a roof grouting. Background Art

[0002] At present, side filling and goaf-retaining goaf is a pillar-free mining technology commonly used in mines at home and abroad. High-water materials, concrete and paste materials are usually used as side filling materials. The pre-proportioned filling materials are injected into the filling template. After the filling materials solidify, they support the lateral roof of the goaf and retain the goaf to serve the next section of the working face. The paste filling material has high initial strength, long support time and low cost. It is currently the most commonly used filling material in goaf-retaining goaf. However, it cannot effectively connect to the top during the filling process, resulting in a gap between the top of the wall and the roof. Not only will it cause the lateral roof of the working face to sink and impact and damage the filling body, it will also cause air leakage in the goaf and spontaneous combustion of coal in the goaf. Summary of the Invention

[0003] The purpose of this application is to overcome the above problems and provide a method for protecting the tunnel by coordinating tunnel side filling and roof grouting.

[0004] The technical solution of the present application provides a method for coordinating tunnel protection with tunnel side filling and roof grouting, comprising the following steps:

[0005] S01: Drill a hole in the fractured surrounding rock on one side of the goaf along the roadway direction to obtain a roof hole;

[0006] S02: Arranging a roadside filling wall structure below the top plate drill hole, and filling the roadside filling wall structure with waste rock;

[0007] S03: Grouting is performed on the top plate drill hole and the interior of the tunnel side filling wall structure respectively;

[0008] S04: After the slurry inside the tunnel side filling wall structure solidifies, a tunnel side filling body is formed, and the tunnel side filling wall structure is demolished.

[0009] Furthermore, step S01 includes:

[0010] Determine the top drilling spacing;

[0011] According to the top drilling hole spacing, a drilling rig is used to drill holes on the top of the roadside wall and the fractured surrounding rock on one side of the goaf along the roadway direction to obtain top drilling holes, and the inclination angle of the top drilling holes is 30° to 60°.

[0012] Furthermore, the step S01 further includes:

[0013] Determine the top drill hole spacing using the following formula:

[0014]

[0015] Where r is the top borehole spacing, k is the rock permeability coefficient, t is the grouting time, h is the grouting pressure, R is the diameter of the grouting casing, c is the relative viscosity of the slurry, and n is the rock porosity.

[0016] Furthermore, the lane side filling wall structure includes a grouting side baffle arranged toward the lane, three side baffles and a middle baffle;

[0017] Step S02 includes:

[0018] Three side baffles are arranged below the top plate drill hole, and the top ends of the side baffles abut against the top plate of the goaf to form a gangue filling space;

[0019] Filling the gangue in the gangue filling space, wherein the filling height of the gangue is lower than the height of the side baffle;

[0020] The grouting side baffles are arranged and the middle baffle cover is arranged above the gangue filling space, the middle baffle is in contact with the gangue, and the top end of the grouting side baffle is in contact with the roof of the goaf.

[0021] Furthermore, the filling height of the gangue is 4 / 5 of the height of the side baffle.

[0022] Furthermore, the grouting side baffle is provided with at least two side plate grouting holes, and the middle baffle is provided with a grouting opening penetrating the middle baffle;

[0023] Step S02 further includes:

[0024] Before filling the gangue, pre-buried temperature-sensitive capsules are placed inside the wall structure beside the lane;

[0025] Arrange a first pressure sensor at the bottom of the middle baffle;

[0026] A second pressure sensor is provided on the top of one of the side baffles;

[0027] A pressure regulating valve is arranged at each of the side plate grouting holes.

[0028] Furthermore, step S03 includes:

[0029] When grouting the interior of the tunnel side filling wall structure, it includes:

[0030] Slurry is injected from the grouting holes of the side plate, and the temperature-sensitive capsule is dissolved to form a dyeing halo;

[0031] Controlling each of the pressure regulating valves according to the coverage of the dyeing halo;

[0032] When the coverage rate is greater than or equal to a first preset value, increasing the pressure of the pressure regulating valve to the first preset pressure value;

[0033] When the coverage rate is greater than or equal to a second preset value, increasing the pressure of the pressure regulating valve to a second preset pressure value;

[0034] When the pressure value of the first pressure sensor reaches a first preset pressure value, stopping grouting;

[0035] After the slurry solidifies, the slurry is injected again from the side plate grouting hole until the pressure value of the second sensor reaches a second preset pressure value, and the slurry injection is stopped to seal the side plate grouting hole.

[0036] Furthermore, step S03 further includes:

[0037] Calculate the coverage rate of the dye halo in the grouting area corresponding to each side plate grouting hole and the average coverage rate of the dye halo in all grouting areas;

[0038] increasing the pressure of the pressure regulating valve corresponding to the area where the coverage is less than the average coverage;

[0039] Lowering the pressure of the pressure regulating valve corresponding to the area where the coverage rate is greater than the average coverage rate;

[0040] When the coverage of all dyeing halos is basically the same, adjust the pressure of all pressure regulating valves back.

[0041] Furthermore, in step S03, before sealing the side plate grouting holes, the method further includes:

[0042] After the slurry solidifies, detecting the pressure value of the second sensor;

[0043] If the pressure value of the second sensor is lower than the third preset pressure value, continue to inject slurry from the side plate grouting hole until the pressure value of the second sensor reaches the second preset pressure value, and then stop grouting.

[0044] Furthermore, step S04 includes:

[0045] After the slurry inside the tunnel side filling wall structure solidifies, a tunnel side filling body is formed, and the tunnel side filling wall structure is removed;

[0046] Tension anchor rods are arranged on the tunnel side filling body.

[0047] The above technical solution has the following beneficial effects:

[0048] The present application provides a method for collaboratively protecting the tunnel by combining a tunnel side filling body with a roof grouting. A roof hole is drilled along the tunnel direction on the fractured surrounding rock on one side of the goaf, and a tunnel side filling wall structure is arranged below the hole. After gangue is filled inside the hole, grouting is performed on the roof hole and the inside of the tunnel side filling wall structure respectively. After the slurry inside the tunnel side filling wall structure solidifies, a tunnel side filling body is formed. Finally, the tunnel side filling wall structure is dismantled. The support advantages of roof grouting and tunnel side filling are jointly exerted, and the roof hazards caused by the surrounding rock and water-rich rock formations are effectively controlled, the overall stability of the tunnel is significantly improved, and it is helpful to prevent disasters such as water inrush and roof collapse from the tunnel roof. The method is suitable for high-risk tunnel support in weak surrounding rock and water-rich areas. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] The disclosure of this application will become easier to understand with reference to the accompanying drawings. It should be understood that these drawings are for illustrative purposes only and are not intended to limit the scope of protection of this application. In the drawings:

[0050] Figure 1 This is a workflow diagram of a method for coordinating tunnel protection with tunnel side filling and roof grouting in one embodiment of the present application;

[0051] Figure 2 This is a schematic diagram of a tunnel side filling body and a roof grouting system that cooperate to protect the tunnel in one embodiment of the present application;

[0052] Figure 3 This is a three-dimensional diagram of a lane-side filling wall structure in one embodiment of the present application;

[0053] Figure 4 It is a top view of the middle baffle in one embodiment of the present application.

[0054] Reference table of accompanying symbols:

[0055] Top plate drilling 1;

[0056] Filling wall structure 2: grouting side baffle 21, side plate grouting hole 211, side baffle 22, middle baffle 23, grouting outlet 231, gangue filling space 24, first pressure sensor 25, second pressure sensor 26;

[0057] Pressure regulating valve 3. DETAILED DESCRIPTION

[0058] The specific implementation of this application is further described below with reference to the accompanying drawings.

[0059] It is easy to understand that according to the technical solution of this application, a variety of structural methods and implementation methods can be replaced with each other by those skilled in the art without changing the essential spirit of this application. Therefore, the following specific embodiments and drawings are only exemplary descriptions of the technical solution of this application and should not be regarded as the entire application or as a limitation or restriction of the technical solution of the application.

[0060] In this specification, directional terms such as "up," "down," "left," "right," "front," "back," "front," "back," "top," and "bottom" are defined relative to the configurations shown in the accompanying drawings. These terms are relative and may vary depending on the device's location or usage. Therefore, these and other directional terms should not be construed as restrictive. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0061] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0062] like Figure 1 As shown, a workflow diagram of a method for coordinating tunnel protection with tunnel side filling and roof grouting in one embodiment of the present application includes:

[0063] S01: Drill a hole in the fractured surrounding rock on one side of the goaf along the roadway direction to obtain roof borehole 1;

[0064] S02: Arranging a roadside filling wall structure 2 below the roof drill hole 1, and filling the roadside filling wall structure 2 with waste rock;

[0065] S03: Grouting is performed on the top plate drill hole 1 and the interior of the tunnel side filling wall structure 2 respectively;

[0066] S04: After the slurry inside the tunnel side filling wall structure 2 solidifies to form a tunnel side filling body, the tunnel side filling wall structure 2 is removed.

[0067] Specifically, in step S01, a roof borehole 1 is obtained by drilling a hole in the fractured surrounding rock on one side of the goaf along the direction of the tunnel, forming a grouting channel connecting the aquifer and the tunnel roof, so that the roof slurry can directly enter the fracture development layer during subsequent grouting, effectively blocking the infiltration water channel, taking into account the support and waterproofing functions, slowing down the roof settlement, and improving the stability of the tunnel upper structure.

[0068] In step S02, a tunnel side filling wall structure 2 is arranged below the top plate drill hole 1, and gangue is filled in the tunnel side filling wall structure 2, wherein the gangue is loose gangue with a particle size not greater than 100 mm. The structural strength of the gangue is used to improve the overall bearing capacity of the filling body, and the gangue is widely available and low in cost, and is suitable for on-site construction.

[0069] In step S03, grouting is performed on the inside of the top plate drill hole 1 and the tunnel side filling wall structure 2 respectively to form a double-layer structure, and the structure of the top plate and the tunnel side filling body is strengthened simultaneously to form a combined support body, to reinforce the surrounding rocks such as fractures, weaknesses, and water-rich rocks, and to enhance the deformation resistance and anti-seepage capabilities.

[0070] In step S04, after the slurry inside the tunnel side filling wall structure 2 solidifies, a tunnel side filling body is formed, and the tunnel side filling wall structure 2 is removed to expose the solidified tunnel side filling body. The removed tunnel side filling wall structure 2 can be partially recycled and used for subsequent construction, thereby improving material utilization.

[0071] The present application provides a method for collaboratively protecting tunnels by combining a tunnel side filling body with a roof grouting. A roof drilling hole 1 is drilled along the tunnel direction on the fractured surrounding rock on one side of the goaf, and a tunnel side filling wall structure 2 is arranged below the drilling hole. After gangue is filled inside the drilling hole 1 and the inside of the tunnel side filling wall structure 2, grouting is performed respectively. After the slurry inside the tunnel side filling wall structure 2 solidifies, a tunnel side filling body is formed. Finally, the tunnel side filling wall structure 2 is dismantled. The supporting advantages of roof grouting and tunnel side filling are jointly exerted, and the roof hazards caused by the surrounding rock and water-rich rock formations are effectively controlled, the overall stability of the tunnel is significantly improved, and it is helpful to prevent disasters such as water inrush and roof collapse from the tunnel roof. The method is suitable for high-risk tunnel support in weak surrounding rock and water-rich areas.

[0072] like Figure 2 As shown, in one embodiment, step S01 includes:

[0073] Determine the top drilling spacing;

[0074] According to the top drilling hole spacing, a drilling rig is used to drill holes on the top of the roadside wall and the fractured surrounding rock on one side of the goaf along the roadway direction to obtain top drilling holes, and the inclination angle of the top drilling holes is 30° to 60°.

[0075] In this embodiment, the top drill hole spacing is first determined, and based on the determined top drill hole spacing, a drilling rig is used to arrange top drill holes in the fractured surrounding rock on the top of the side wall and on one side of the goaf along the direction of the tunnel. The inclination angle of the top drill hole is 30° to 60°, which makes it easier for the drill hole to enter the fracture development area or water-rich rock layer, improves the contact efficiency between the slurry and the surrounding rock, and is conducive to quickly sealing the fractures in the early stage of support and reducing the permeability, thereby effectively improving the overall stability of the tunnel roof and preventing roof water inrush and roof collapse disasters.

[0076] In another embodiment, the step S01 further includes

[0077] Determine the top drill hole spacing using the following formula:

[0078]

[0079] Where r is the top borehole spacing, k is the rock permeability coefficient, t is the grouting time, h is the grouting pressure, R is the diameter of the grouting casing, c is the relative viscosity of the slurry, and n is the rock porosity.

[0080] In this embodiment, k is the rock permeability coefficient, which can be 1.5×10 -2 cm / s; t is the grouting time, which can be 7200s; h is the grouting pressure; R is the diameter of the grouting casing, which can be 50mm; c is the relative viscosity of the slurry, which can be 2.5; n is the porosity of the rock formation, which can be 3%.

[0081] The introduction of a calculation formula to determine the top drill hole spacing can accurately control the drill hole layout according to the actual geological conditions and grouting parameters, avoiding grouting blind areas caused by excessively large drill hole spacing, or waste of resources caused by excessively small drill hole spacing, thereby achieving efficient diffusion and uniform reinforcement of the slurry in the fractured surrounding rock, improving the grouting utilization rate and reinforcement effect, and effectively ensuring the stability and safety of the tunnel roof.

[0082] like Figure 3 As shown, in another embodiment, the roadside filling wall structure 2 includes a grouting side baffle 21 arranged toward the roadway, three side baffles 22 and a middle baffle 23;

[0083] Step S02 includes:

[0084] Three side baffles 22 are arranged below the top plate drill hole 1, and the top ends of the side baffles 22 abut against the top plate of the goaf to form a gangue filling space 24;

[0085] Gangue is filled in the gangue filling space 24 , and the filling height of the gangue is lower than the height of the side baffle 22 ;

[0086] The grouting side baffles 21 are arranged and the middle baffles 23 are covered above the gangue filling space 24 . The middle baffles 23 abut against the gangue, and the top ends of the grouting side baffles 21 abut against the roof of the goaf.

[0087] In this embodiment, the arrangement of the roadside filling wall structure 2 includes arranging three side baffles 22 below the top plate drill hole 1. The top of the side baffle 22 abuts against the top plate of the goaf. The three side top plates form a semi-closed space, which is the gangue filling space 24. Gangue is filled in the gangue filling space 24, and the filling height of the gangue is lower than the height of the side baffle 22. After the filling is completed, the grouting side baffle 21 is arranged to enclose the gangue filling space 24. The grouting side baffle 21 The top of the baffle 23 is in contact with the top plate of the goaf, and the middle baffle 23 is horizontally covered above the gangue filling space 24. At this time, the middle baffle 23 is in contact with the gangue below, and the side surfaces of the middle baffle 23 are respectively connected with the inner side of the grouting side baffle 21 and the inner sides of the three side baffles 22. A part of the space at the height of the side baffle 22 is still retained above the middle baffle 23, providing a grouting chamber for the upper high-plasticity grouting body, and finally forming a composite filling structure with upper and lower layers.

[0088] The middle baffle 23 is in direct contact with the gangue to achieve isolation between the upper and lower layers, which facilitates the subsequent slurry injection and consolidation of the lower gangue, and realizes the layered construction of gangue particles, lower slurry combination and upper slurry, forming a roadside filling body with stable structure and strong support capacity.

[0089] In one embodiment, one of the side baffles 22 and the grouting side baffle 21 has a length of 6100 mm, the other two side baffles 22 have a length of 1600 mm, the middle partition has a size of 6100 mm × 1600 mm, and the thickness of all baffles is 10 mm.

[0090] like Figure 3 As shown, in one preferred embodiment, the filling height of the gangue is 4 / 5 of the height of the side baffle 22.

[0091] In this preferred embodiment, by controlling the filling height of the gangue to 4 / 5 of the height of the side baffle 22, reserving the upper 1 / 5 space for the injection of high-plasticity slurry, an upper and lower layered filling structure is realized, which is conducive to full contact between the slurry and the top plate, enhancing the strength of the top plate, and at the same time ensuring the stable bonding between the gangue and the slurry, thereby improving the bearing performance and structural stability of the overall filling body.

[0092] like Figure 3 、 Figure 4 As shown, in another embodiment, the grouting side baffle 21 is provided with at least two side plate grouting holes 211, and the middle baffle 23 is provided with a grouting opening 231 penetrating the middle baffle 23;

[0093] Step S02 further includes:

[0094] Before filling the gangue, temperature-sensitive capsules are embedded inside the wall structure 2 beside the lane;

[0095] A first pressure sensor 25 is arranged at the bottom of the intermediate baffle 23;

[0096] A second pressure sensor 26 is provided on the top of one of the side baffles 22;

[0097] A pressure regulating valve 3 is arranged at each of the side plate grouting holes 211 .

[0098] In this embodiment, the grouting side baffle 21 is provided with at least two side plate grouting holes 211, and the middle baffle 23 is provided with a slurry leakage port 231, so as to achieve the effect of slurry injection from multiple points and uniform penetration, thereby avoiding local slurry accumulation or insufficient penetration.

[0099] Before filling the gangue, temperature-sensitive capsules are embedded in the filling wall structure 2 beside the tunnel. During the subsequent grouting process, the temperature-sensitive capsules break and display color to feedback the grouting coverage, thereby improving the visualization and precise control capabilities of the grouting process.

[0100] A first pressure sensor 25 is arranged at the bottom of the middle baffle 23, and a second pressure sensor 26 is arranged on the top of one of the side baffles 22, which can monitor the grouting pressure and permeability status of each part in real time. In conjunction with the pressure regulating valve 3 arranged at the grouting holes 211 of each side plate, regional pressure control can be achieved, effectively improving the density of the filling body beside the roadway and the overall support effect, thereby enhancing the stability of the roof.

[0101] In one embodiment, the slurry leakage openings 231 arranged on the middle baffle 23 have a diameter of φ200 mm, and the distance between the two slurry leakage openings 231 is 550 mm.

[0102] In another embodiment, step S03 includes:

[0103] When grouting the interior of the tunnel side filling wall structure 2, the process includes:

[0104] Slurry is injected from the side plate grouting hole 211, and the temperature-sensitive capsule is dissolved to form a dyeing halo;

[0105] Controlling each of the pressure regulating valves 3 according to the coverage of the dyeing halo;

[0106] When the coverage rate is greater than or equal to a first preset value, the pressure of the pressure regulating valve 3 is increased to the first preset pressure value;

[0107] When the coverage rate is greater than or equal to a second preset value, the pressure of the pressure regulating valve 3 is increased to a second preset pressure value;

[0108] When the pressure value of the first pressure sensor 25 reaches a first preset pressure value, grouting is stopped;

[0109] After the slurry solidifies, the slurry is injected again from the side plate grouting hole 211 until the pressure value of the second sensor reaches a second preset pressure value, and the slurry injection is stopped to seal the side plate grouting hole 211.

[0110] In this embodiment, slurry is injected from the grouting hole 211 of the side plate, and the temperature-sensitive capsule will dissolve to form a dyeing halo. The technicians can control each pressure regulating valve 3 according to the coverage of the dyeing halo, and adopt visual grouting management. After the slurry penetrates into the corresponding area, the dye can be dissolved and released to form a clean dyeing halo, which serves as an intuitive basis for the slurry penetration range and realizes precise control of the grouting rate and range of different areas.

[0111] When the coverage rate is greater than or equal to the first preset value, the pressure of each pressure regulating valve 3 is increased to the first preset pressure value, thereby expanding the grouting range. When the coverage rate is greater than or equal to the second preset value, technicians can enter the high-pressure grouting stage and continue to increase the pressure of each pressure regulating valve 3 to the second preset pressure value, thereby enhancing the structural density.

[0112] When the pressure value of the first pressure sensor 25 provided at the bottom of the intermediate baffle 23 reaches the first preset pressure value, it means that the slurry has been effectively mixed with the gangue at the bottom and filled the gaps in the gangue at the bottom, and the slurry injection is stopped at this time.

[0113] After the slurry initially solidifies to form a gangue-based polymer filling body at the bottom, continue to inject slurry from the side plate grouting hole 211 until the pressure value of the second pressure sensor 26 set at the top of one of the side baffles 22 reaches the second preset pressure value, indicating that the slurry has now filled the upper space above the middle baffle 23 and is fully fitted with the top plate of the goaf, achieving dense filling and sealing under the top plate, effectively controlling the risk of water seepage and falling of the top plate. At this time, stop injecting slurry and seal the side plate grouting hole 211.

[0114] In one embodiment, the slurry is a high plastic filling slurry, including gangue particles, Portland cement, and EVA polymer in a mass ratio of 5:4:1;

[0115] The water-binder ratio is 0.55 and the amount of water reducer is 1wt%.

[0116] In one preferred embodiment, step S03 further includes:

[0117] Calculate the coverage rate of the dye halo in the grouting area corresponding to each side plate grouting hole 211 and the average coverage rate of the dye halo in all grouting areas;

[0118] Increase the pressure of the pressure regulating valve 3 corresponding to the area where the coverage rate is less than the average coverage rate;

[0119] Lowering the pressure of the pressure regulating valve 3 corresponding to the area where the coverage rate is greater than the average coverage rate;

[0120] When the coverage of all dyeing halos is basically the same, the pressure of all pressure regulating valves 3 is adjusted back.

[0121] In this preferred embodiment, the coverage rate of the dye halo of the grouting area corresponding to each side plate grouting hole 211 is calculated and compared with the average coverage rate of all grouting areas, thereby achieving dynamic adjustment of the grouting pressure in different zones.

[0122] The dye halo is a visual mark formed when the thermosensitive capsule releases dye and changes color after being exposed to temperature and pressure during the grouting process. Its coverage range represents the actual penetration boundary of the slurry. Therefore, pressure control based on the coverage rate can transform the grouting process that originally relied on experience and judgment into a quantifiable and adjustable intelligent control process.

[0123] Specifically, when the dye coverage rate of the area corresponding to the side plate grouting hole 211 is lower than the average, it indicates that the grouting volume in this area is insufficient or the penetration resistance is large. At this time, the technician can increase the pressure of the corresponding pressure regulating valve 3 to enhance the grouting driving force and increase the slurry penetration depth. Conversely, when the coverage rate is higher than the average, the pressure is appropriately lowered to avoid excessive accumulation or loss of slurry in this area. Finally, when the dye haloes in each area tend to be balanced, indicating that the slurry penetration distribution has reached an ideal state, the pressure of all pressure regulating valves 3 is uniformly adjusted back to the pressure before adjustment, which not only avoids system overload, but also saves grouting materials and improves construction economy and efficiency.

[0124] This regulation mechanism realizes refined zoning control during the grouting process, enhances the slurry distribution uniformity and filling density, improves the bearing capacity, compressive strength and durability of the overall tunnel side support body, and has significant engineering value for surrounding rock control under complex geological conditions.

[0125] In another preferred embodiment, in step S03, before sealing the side plate grouting holes 211, the following steps are further included:

[0126] After the slurry solidifies, detecting the pressure value of the second sensor;

[0127] If the pressure value of the second sensor is lower than the third preset pressure value, the grouting continues to be injected from the side plate grouting hole 211 until the pressure value of the second sensor reaches the second preset pressure value, and the grouting is stopped.

[0128] In this preferred embodiment, the pressure value of the second sensor arranged on the top of one of the side baffles 22 is monitored and compared in multiple stages. After the slurry solidifies, if the pressure value of the second sensor is lower than the third preset pressure value, the slurry may settle and precipitate water, resulting in voids. Slurry needs to be injected from the side plate grouting hole 211 again until the pressure value of the second sensor reaches the second preset pressure value. The slurry injection can be stopped and the side plate grouting hole 211 can be sealed to prevent voids caused by slurry settling, water extraction or uneven grouting, thereby improving the density and overall strength of the roadside filling.

[0129] In another preferred embodiment, after the slurry at the bottom of the middle baffle 23 solidifies, before injecting slurry again from the side plate grouting hole 211, the method further includes:

[0130] After the slurry solidifies, detecting the pressure value of the first sensor;

[0131] If the pressure value of the first sensor is lower than the fourth preset pressure value, the grouting continues to be injected from the side plate grouting hole 211 until the pressure value of the first sensor reaches the first preset pressure value, and the grouting is stopped.

[0132] In this preferred embodiment, the first pressure sensor 25 provided at the bottom of the intermediate baffle 23 can detect its pressure value again after the slurry initially sets, and evaluate the bottom gangue-based polymer filling body formed by the mixture of bottom gangue and slurry. If the pressure value of the first pressure sensor 25 is lower than the fourth preset pressure value, the bottom slurry may undergo water separation, sedimentation, etc., and there may be partial gaps between the slurry and the gangue or uneven grouting. At this time, continuing to inject slurry through the side plate grouting hole 211 can effectively reinforce the lower layer area until the pressure value reaches the first preset pressure value, ensuring that the slurry fully fills the gaps in the bottom gangue to form a dense and stable gangue-based polymer filling body.

[0133] In one embodiment, step S04 includes:

[0134] After the slurry inside the tunnel side filling wall structure 2 solidifies to form a tunnel side filling body, the tunnel side filling wall structure 2 is removed;

[0135] Tension anchor rods are arranged on the tunnel side filling body.

[0136] In this embodiment, after the slurry inside the tunnel side filling wall structure 2 solidifies, the tunnel side filling body can be formed. At this time, it has the bearing capacity and the original tunnel side filling wall structure 2, such as the grouting side baffle 21 and the three side baffles 22, can be removed to provide space for the subsequent arrangement of anchor rods. At the same time, part of the recovered wall structure can also be continued to be used, saving engineering costs.

[0137] Laying tension anchor rods on the formed tunnel side filling body can establish a stable mechanical connection between the tunnel side filling body and the surrounding rock mass, improve its overall shear strength, further enhance the support effect, control the deformation of the surrounding rock and the displacement of the roof, and ensure the stability of the tunnel.

[0138] In one embodiment, the spacing between the tension anchors arranged in the tunnel side filling wall is 1000mm×1200mm, and the anchor specifications are φ40mm×1600mm.

[0139] As needed, the above-mentioned technical solutions can be combined to achieve the best technical effect. The above description is only the principle and preferred embodiment of the present application. It should be pointed out that for ordinary technicians in this field, the implementation methods obtained by appropriately combining the technical solutions disclosed in different embodiments are also included in the technical scope of the present invention. On the basis of the principles of the present application, several other variations can be made, which should also be regarded as the scope of protection of the present application.

Claims

1. A method for protecting a tunnel by synergistically combining tunnel side filling with roof grouting, characterized in that: The steps include: S01: Drill a hole in the fractured surrounding rock on one side of the goaf along the roadway direction to obtain a roof hole; S02: Arranging a roadside filling wall structure below the top plate drill hole, and filling the roadside filling wall structure with waste rock; S03: Grouting is performed on the top plate drill hole and the interior of the tunnel side filling wall structure respectively; S04: After the slurry inside the tunnel side filling wall structure solidifies, a tunnel side filling body is formed, and the tunnel side filling wall structure is demolished.

2. The method for protecting a tunnel by combining tunnel side filling with roof grouting according to claim 1, characterized in that: Step S01 includes: Determine the top drilling spacing; According to the top drilling hole spacing, a drilling rig is used to drill holes on the top of the roadside wall and the fractured surrounding rock on one side of the goaf along the roadway direction to obtain top drilling holes, and the inclination angle of the top drilling holes is 30° to 60°.

3. The method for protecting a tunnel by combining tunnel side filling with roof grouting according to claim 2, characterized in that: The step S01 further includes: Determine the top drill hole spacing using the following formula: Where r is the top borehole spacing, k is the rock permeability coefficient, t is the grouting time, h is the grouting pressure, R is the diameter of the grouting casing, c is the relative viscosity of the slurry, and n is the rock porosity.

4. The method for protecting a tunnel by combining tunnel side filling with roof grouting according to claim 1, characterized in that: The roadside filling wall structure includes a grouting side baffle arranged toward the roadway, three side baffles and a middle baffle; Step S02 includes: Three side baffles are arranged below the top plate drill hole, and the top ends of the side baffles abut against the top plate of the goaf to form a gangue filling space; Gangue is filled in the gangue filling space, and the filling height of the gangue is lower than the height of the side baffle; The grouting side baffles are arranged and the middle baffle cover is arranged above the gangue filling space, the middle baffle is in contact with the gangue, and the top end of the grouting side baffle is in contact with the roof of the goaf.

5. The method for protecting a tunnel by combining tunnel side filling with roof grouting according to claim 4, characterized in that: The filling height of the gangue is 4 / 5 of the height of the side baffle.

6. The method for protecting a tunnel by combining tunnel side filling with roof grouting according to claim 4, characterized in that: The grouting side baffle is provided with at least two side plate grouting holes, and the middle baffle is provided with a grouting opening penetrating the middle baffle; Step S02 further includes: Before filling the gangue, pre-buried temperature-sensitive capsules are placed inside the wall structure beside the lane; Arrange a first pressure sensor at the bottom of the middle baffle; A second pressure sensor is provided on the top of one of the side baffles; A pressure regulating valve is arranged at each of the side plate grouting holes.

7. A method for protecting a tunnel by combining tunnel side filling with roof grouting according to claim 6, characterized in that: Step S03 includes: When grouting the interior of the tunnel side filling wall structure, it includes: Slurry is injected from the grouting holes of the side plate, and the temperature-sensitive capsule is dissolved to form a dyeing halo; Controlling each of the pressure regulating valves according to the coverage of the dyeing halo; When the coverage rate is greater than or equal to a first preset value, increasing the pressure of the pressure regulating valve to the first preset pressure value; When the coverage rate is greater than or equal to a second preset value, increasing the pressure of the pressure regulating valve to a second preset pressure value; When the pressure value of the first pressure sensor reaches a first preset pressure value, stopping grouting; After the slurry solidifies, the slurry is injected again from the side plate grouting hole until the pressure value of the second sensor reaches a second preset pressure value, and the slurry injection is stopped to seal the side plate grouting hole.

8. The method for protecting a tunnel by combining tunnel side filling with roof grouting according to claim 7, characterized in that: Step S03 also includes: Calculate the coverage rate of the dye halo in the grouting area corresponding to each side plate grouting hole and the average coverage rate of the dye halo in all grouting areas; increasing the pressure of the pressure regulating valve corresponding to the area where the coverage is less than the average coverage; Lowering the pressure of the pressure regulating valve corresponding to the area where the coverage rate is greater than the average coverage rate; When the coverage of all dyeing halos is basically the same, adjust the pressure of all pressure regulating valves back.

9. The method for protecting a tunnel by combining tunnel side filling with roof grouting according to claim 7, characterized in that: In step S03, before sealing the side plate grouting holes, the following steps are further included: After the slurry solidifies, detecting the pressure value of the second sensor; If the pressure value of the second sensor is lower than the third preset pressure value, continue to inject slurry from the side plate grouting hole until the pressure value of the second sensor reaches the second preset pressure value, and then stop grouting.

10. The method for protecting a tunnel by combining tunnel side filling with roof grouting according to claim 1, characterized in that: Step S04 includes: After the slurry inside the tunnel side filling wall structure solidifies, a tunnel side filling body is formed, and the tunnel side filling wall structure is removed; Tension anchor rods are arranged on the tunnel side filling body.

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