Filling tunnel retaining wall and construction method thereof

Abstract

The invention provides a filling tunnel retaining wall and a construction method thereof, and relates to the technical field of underground mine subsequent filling. According to the filling mine tunnel retaining wall, after the force application assemblies, the stiffening strips, the stiffened strips, the pressure sensors and the displacement sensors are installed on the flexible formworks (geotechnical bags), the flexible formworks are placed at the section of a roadway needing to be filled, the flexible formworks are filled with slurry through the grouting openings in the flexible formworks, and then the filling mine tunnel retaining wall is manufactured through maintenance. The flexible formwork is designed to be of an integrated step-shaped structure, the design of the surface layer stiffening strips is combined, the gravity center of the retaining wall can be lowered, bottom friction force is enhanced, and therefore the overall stability and the anti-overturning capacity are greatly improved; a metal plate-piston hydraulic device and a servo control mechanism are adopted to apply and dynamically adjust pressure to the retaining wall in the maintenance period, and a sensor is matched for real-time monitoring, so that leakage and deformation are effectively prevented. By means of the method, the filling tunnel retaining wall which has the advantages of being simple in structure, stable in structure, high in compressive strength and the like is manufactured.

Description

Technical Field

[0001] This invention relates to the field of underground mine backfilling technology, and in particular to a mine tunnel retaining wall and its construction method. Background Technology

[0002] To improve mine production efficiency and solve tailings disposal problems, backfilling mining has been widely used in underground mining. Backfilling retaining walls, as key structures in this process, function to seal off the access route to the goaf, withstand the lateral pressure of the backfill slurry, and ensure the safe and efficient backfilling operation.

[0003] Currently, common types of infill retaining walls include lightweight retaining walls, gravity retaining walls, and layered bag-type self-supporting infill retaining walls, but each has significant limitations: Lightweight retaining walls (such as those made of wood or other lightweight materials) are simple to construct, have a short construction period, and low overall cost, but their overall strength and rigidity are insufficient, making them unable to withstand high grout pressure. They are generally only suitable for small-section tunnels or low-pressure infill conditions; Gravity retaining walls (mainly including concrete, red brick, and rubble structures) have the advantages of structural stability and high load-bearing capacity, making them suitable for large-section and high-pressure infill conditions, but their masonry materials (such as concrete) Materials (such as bricks and stones) mostly need to be purchased externally. In mines with wide-ranging roadways and limited working space, transportation costs are high, and mechanized construction is difficult to achieve. It mainly relies on manual labor, resulting in low construction efficiency, long cycle, and affecting the overall mining progress. Although layered bag self-supporting backfill retaining walls can "use local materials" to make filling bags using filling slurry, reducing material and transportation costs, the layered filling method is cumbersome and has low construction efficiency. At the same time, the slurry inside the bags is prone to consolidation and settlement under its own weight stress. If maintenance is not timely, leakage or even collapse may occur during the filling process, posing a significant safety hazard.

[0004] In summary, existing infill retaining walls struggle to balance structural strength, material costs, construction efficiency, and safety and stability. In particular, there is a lack of a new type of retaining wall structure that can meet the requirements of large-section high-pressure filling, achieve rapid mechanized construction, controllable costs, and ensure safety and reliability.

[0005] In view of this, it is necessary to design an improved retaining wall for filling mine tunnels and its construction method to solve the above problems. Summary of the Invention

[0006] The purpose of this invention is to provide a mine tunnel retaining wall and its construction method.

[0007] To achieve the above-mentioned objectives, in a first aspect, the present invention provides a mine tunnel retaining wall, comprising:

[0008] The supporting structure, part of which is a hierarchical structure, has the same overall shape as the tunnel cross-section, including an integrated flexible template and filling grout.

[0009] A force-applying component for applying force to the support body includes a fixing module and a piston member. The fixing module includes two fixing plates, which are respectively disposed on two opposite sides of the support body. The piston member is disposed between the two fixing plates of the fixing module.

[0010] Preferably, the supporting body is stepped, with the length of the uppermost step being 1-1.5 m, the length difference between two adjacent steps being 1-2 m, and the height of each step being 0.8-1.2 m.

[0011] Preferably, the support body is provided with a plurality of reinforcing strips and stiffening strips at intervals.

[0012] Preferably, one of the fixing plates is disposed on the side of the support body that contacts the roadway cross section.

[0013] Preferably, the fixing plate is provided with a plurality of pressure sensors, and the support body is provided with a plurality of displacement sensors.

[0014] Preferably, the thickness of the fixing plate is 50-100 mm.

[0015] Preferably, the width of the stiffening strip is 20-40 cm, the width of the reinforcing strip is 10-20 cm, and the interval between adjacent reinforcing strips and stiffening strips is 30-40 cm.

[0016] Preferably, the piston component comprises a metal tube and an electro-hydraulic piston device.

[0017] Secondly, the present invention provides a method for constructing a retaining wall for filling a mine tunnel, comprising the following steps:

[0018] S1. After installing the force application components, stiffening strips, reinforcing strips, pressure sensors, and displacement sensors on the flexible template, the flexible template is placed at the tunnel section that needs to be filled. Grout is then filled into the flexible template through the grouting port on the flexible template. The grout and the flexible template together constitute the supporting body. The grout injection rate is 0.5-1.0 m / h.

[0019] S2. After grouting is completed, the grouting port is closed, and the force application component is used to apply pressure to the support body so that the support body abuts against the roadway cross section.

[0020] S3. Allow the filling slurry to cure completely, thus obtaining the filling mine retaining wall.

[0021] The beneficial effects of this invention are:

[0022] The present invention provides a method for constructing retaining walls in mine tunnels. This method involves directly filling geotextile bags with filling slurry prepared at a mine filling station on-site at the tunnel cross-section to be filled, significantly reducing material and transportation costs and effectively solving the problem of tailings disposal. By designing the geotextile bags as an integrated stepped structure combined with surface reinforcing strips, the center of gravity of the retaining wall is lowered and the bottom friction is enhanced, thereby greatly improving overall stability and anti-overturning capacity. Simultaneously, the method employs a metal plate-piston hydraulic device and servo control mechanism to apply and dynamically adjust pressure to the retaining wall during curing, coupled with real-time monitoring by sensors, ensuring that the retaining wall remains tightly fitted to the tunnel cross-section, effectively preventing leakage and deformation. The above method has the combined advantages of simple construction, strong applicability, recyclability, high degree of automation and good safety. The resulting filling retaining wall has the advantages of low material cost, simple construction, stable structure and high compressive strength. It has strong applicability. In addition, geotextile bags of different specifications can be prefabricated according to the cross-sectional size of the tunnel, which significantly reduces the construction difficulty and improves the construction efficiency. Attached Figure Description

[0023] Figure 1 A schematic diagram of the overall structure of the mine tunnel retaining wall provided by the present invention;

[0024] Figure 2 for Figure 1 A side view from a certain angle;

[0025] Figure 3 for Figure 1 Top view;

[0026] The attached figures are labeled as follows:

[0027] 10. Support body; 11. Displacement sensor; 12. Reinforcing strip; 13. Stiffening strip; 20. Force application component; 21. Fixing plate; 22. Piston component. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0029] It should also be noted that, in order to avoid obscuring the present invention with unnecessary details, only the structures and / or processing steps closely related to the present invention are shown in the accompanying drawings, while other details that are not closely related to the present invention are omitted.

[0030] Additionally, it should be noted that the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0031] This invention provides a retaining wall for filling mine tunnels, comprising:

[0032] The supporting body 10 has a layered structure in part, and its overall shape is the same as the cross-section of the tunnel. It includes an integrated flexible template and filling slurry filled in it.

[0033] The force-applying component 20, which is used to apply force to the support body 10 to prevent the support body 10 from deviating from the mine tunnel section, includes a fixing module and a piston component 22. The fixing module includes two fixing plates 21, which are respectively disposed on two opposite sides of the support body 10. The piston component 22 is disposed between the two fixing plates 21 of the fixing module.

[0034] Several pressure sensors are installed on the side of the two fixing plates 21 near the support body 10 to monitor the pressure provided by the fixing module to the support body 10 in real time. Several displacement sensors 11 are installed on the side of the support body 10 that contacts the mine tunnel section, and these sensors, together with the pressure sensors, monitor the displacement and pressure changes of the retaining wall. When the displacement change is too large, the servo control system will control the electro-hydraulic piston device to apply greater pressure to the support body 10, lifting the support body 10 until the displacement change decreases to 0. When the displacement change remains at 0, it indicates that the filling slurry inside the support body 10 has completed the consolidation and settling stage, and the servo control system will control the electro-hydraulic piston device to reduce the pressure applied to the support body to facilitate subsequent disassembly. In some embodiments, the number of pressure sensors is 4 and the number of displacement sensors 11 is 4. The number of both can be set according to actual needs and is not limited here.

[0035] Specifically, the supporting body 10 is provided with a number of reinforcing strips 12 and stiffening strips 13 at intervals, such as in the following manner: reinforcing strip-stiffening strip-stiffening strip-stiffening strip-stiffening strip-stiffening strip-stiffening strip… or stiffening strip-stiffening strip-stiffening strip-stiffening strip-stiffening strip-stiffening strip… The reinforcing strips 12 and stiffening strips 13 are used to fix the supporting body 10 to prevent the retaining wall from deforming during use, and at the same time fix the shape of the flexible template to ensure that it maintains its hierarchical structure. It should be noted that the specific arrangement and number of these strips can be set according to the actual situation, as long as it meets the actual application requirements, and are not limited to this here. In some embodiments, to ensure that the strength of the reinforcing strips 12 and 13 can withstand the lateral pressure of the filling grout inside the support body, the width of the reinforcing strip 13 is set to 20-40 cm, the width of the reinforcing strip 12 is set to 10-20 cm, and the interval between adjacent reinforcing strips 12 and 13 is set to 30-40 cm. The thickness of the fixing plate 21 is 50-100 mm. The reinforcing strips 13 and 12 can be fixed to the flexible template surface of the support body 10 by means of adhesive or other methods. The specific fixing method can be selected according to actual needs and is not limited thereto.

[0036] Furthermore, the two fixing plates 21 of the fixing module are arranged such that one is set on the side of the supporting body 10 that is in contact with the tunnel cross section, and the other is set on the side of the supporting body 10 that is opposite to the aforementioned side. The two are arranged opposite to each other, and the thickness of both is 50-100 mm. The connection method between the fixing plate 21 and the flexible template is not limited. It can be detachable, such as snap-fit ​​connection, or fixed, such as adhesive. The specific method can be selected according to actual needs, as long as it can meet the actual application requirements. The material of the fixing plate 21 is preferably metal. The piston component 22, located between the two fixed plates 21, includes a metal tube (not labeled in the figure) and an electro-hydraulic piston device (not labeled in the figure). The diameter of the metal tube is 20-50 mm. Both ends of the metal tube are fixed to the fixed plate 21 on the side near the support body 10. The metal tube is telescopic. The electro-hydraulic device is connected to an external servo control component. It can control the telescopic movement of the metal tube by hydraulic drive according to the changes in the values ​​of the pressure sensor and the displacement sensor. Since the flexible template has a certain degree of telescopicity, as the metal tube telescopically moves, the two fixed plates 21 move closer or further away from each other, thereby adjusting the magnitude of the force applied by the force application component 20 to the support body 10 and realizing dynamic adjustment of pressure. With this configuration, the piston pressure can be dynamically adjusted via a servo mechanism during the process of filling the flexible template with filling slurry to prepare the support body 10. This controls the pressure within the flexible template and prevents the filling slurry from dehydrating and settling during curing, which could damage the overall structure and sealing of the retaining wall. This ensures that the retaining wall and the tunnel section are always tightly fitted. In actual use, considering factors such as construction cost and ease of construction, the force application component 20 can be made detachable.

[0037] More specifically, the flexible template of the supporting body 10 is an integral structure with several grouting ports on its surface for filling the flexible template with grout. Considering the ease of operation in practical applications, the grouting ports are located at the top of the flexible template. When filling with grout, the grout can flow to all corners of the flexible template by its own gravity, ensuring that the flexible template is fully filled with grout. In some embodiments, the diameter of the grouting ports is 30-50 mm. The outline shape of the flexible template is made into an arch, square, or other shape that conforms to the outline of the roadway cross-section according to the actual shape of the roadway cross-section. The design width and height of the flexible template should exceed the maximum cross-sectional width and maximum height of the roadway by 10-20 cm to ensure that the roadway cross-section can be fully filled after the grout is filled into it to form the supporting body 10.

[0038] Specifically, the support body 10 is preferably a stepped, integrated structure. This structure increases the effective thickness and weight distribution of the retaining wall, shifts its center of gravity forward, strengthens its resistance to wall movement, and enhances the stability of the retaining wall. Secondly, the stepped structure of the support body 10 can distribute the enormous overall lateral pressure across each step, allowing the pressure to be transmitted downwards step by step, improving stress distribution within the support body 10 and reducing stress concentration. In some embodiments, the uppermost step of the stepped support body 10 (formed by the last slurry filled into the flexible template) has a length of 1-1.5 m, the length difference between adjacent steps is 1-2 m, and the height of each step is 0.8-1.2 m. The actual number of steps and step height are determined based on the cross-sectional area and actual height of the tunnel.

[0039] Furthermore, the present invention also provides a method for constructing the above-mentioned mine tunnel retaining wall, comprising the following steps:

[0040] S1. After installing the force application component 20, stiffening strip 13, reinforcing strip 12, pressure sensor, and displacement sensor 11 on the flexible template, place the flexible template at the section of the roadway that needs to be filled, and fill the flexible template with grout through the grouting port. The grout and the flexible template together constitute the support body 10. During the filling process, the filling progress needs to be monitored in real time. As the filling work proceeds, the flexible template is filled with grout, and the stiffening strip 13 and reinforcing strip 12 on the surface of the flexible template are stretched, which can fix the flexible template to maintain the hierarchical structure of the flexible template.

[0041] S2. After grouting is completed, the grouting port is closed. At this time, the flexible template is fully unfolded. During the process of the flexible template, the metal pipe is gradually stretched under the control of the electric hydraulic device, causing the two fixed plates 21 to move away from each other. Under this force, the support body 10 can be made to abut against the tunnel section, and the displacement and pressure changes of the retaining wall are monitored in real time through the displacement sensor 11 and the pressure sensor.

[0042] S3. Static curing support body 10, curing time is more than 28 days. During the curing period, the displacement change of the flexible template is monitored in real time, and the pressure is dynamically adjusted through the servo mechanism to ensure that the flexible template retaining wall and the roadway section are always tightly attached during the curing period until the filling slurry is completely cured, thus obtaining the filling mine roadway retaining wall.

[0043] In some embodiments, in step S1, the slurry injection rate is 0.5-1.0 m / h. Adjusting the speed within this range can prevent excessive fluid pressure during filling, which could lead to instability and collapse of the flexible template retaining wall, while ensuring that the flexible template is filled densely.

[0044] In some embodiments, in step S3, the pressure of the flexible template is controlled by the servo mechanism as follows: the pressure is dynamically adjusted according to the data of the pressure sensor and the displacement sensor 11. When the displacement of the sensor is greater than 0 mm, the hydraulic system will immediately apply pressure to the flexible template until the sensor pressure returns to 0 mm. When the pressure of the pressure sensor is greater than 1.0 MPa, the hydraulic system will automatically release part of the pressure to prevent the flexible template from breaking due to excessive pressure.

[0045] In some embodiments, in step S3, the compressive strength of the fully cured slurry is not less than 3 MPa.

[0046] The following specific embodiments further illustrate the mine tunnel retaining wall and its construction method provided by the present invention:

[0047] Example 1

[0048] This embodiment provides a retaining wall for filling mine tunnels; please refer to the specific structure for details. Figure 1-3 As shown, it includes: a support body 10 and a force application component 20. The force application component 20 is used to apply a force to the support body 10 to prevent the support body 10 from deviating from the mine tunnel cross section.

[0049] Specifically, part of the supporting body 10 is a stepped structure with an arched top. Its overall shape is the same as the tunnel cross-section. It includes an integrated geotextile bag and filling slurry inside. The flexible template is 4.2 m wide and 4.0 m high. There are 4 stepped layers, each 1.0 m high. The top step is 1.0 m long, and the step length increases by 1.0 m at each step, with the bottom step being 4 m long. Several reinforcing strips 12 and stiffening strips 13 are spaced apart at the bottom of the geotextile bag. The stiffening strips 13 are 20 cm wide, and the reinforcing strips 12 are 10 cm wide. The interval between adjacent reinforcing strips 12 and stiffening strips 13 is 20 cm. The fixing plate 21 is 50 mm thick and has dimensions of length × width = 3.0 m × 1.0 m. The geotextile bag is made of a water-permeable but aggregate-impermeable membrane material and is integrally formed without any seam or splicing area. In other embodiments, the structure and size of the geotextile bag can be selectively adjusted according to the shape of the tunnel cross-section.

[0050] Furthermore, the force-applying component 20 is arranged in a fixed module and a piston component 22. The fixed module includes two fixed plates 21, which are respectively arranged on two opposite sides of the geotextile bag. The piston component 22 is arranged between the two fixed plates 21 of the fixed module. In this embodiment, the fixed plates 21 are specifically metal plates. One fixed plate 21 is arranged on the side of the support body 10 that contacts the tunnel cross-section, and the other is arranged on the side of the support body 10 that is opposite to the aforementioned side. The two fixed plates 21 are arranged opposite to each other, and the connection between the fixed plates 21 and the geotextile bag can be a snap-fit ​​connection. The piston component 22 arranged between the two fixed plates 21 includes a metal tube and an electro-hydraulic piston device. The diameter of the metal tube is 30 mm. It is connected to an external electro-hydraulic device, which can control the extension and retraction of the metal tube by hydraulic drive according to the changes in the values ​​of the pressure sensor and the displacement sensor 11. This configuration allows for dynamic adjustment of piston pressure via a servo mechanism during the filling of the geotextile bag with grout to prepare the support body 10. This controls the pressure within the geotextile bag, preventing dehydration and settling of the grout inside the geotextile bag during filling and curing, which could damage the overall structure and sealing of the retaining wall. This ensures the retaining wall remains tightly fitted to the tunnel cross-section. Furthermore, the fixing plate 21 is equipped with several pressure sensors, and the geotextile bag is equipped with several displacement sensors 11, located on the side of the fixing plate 21 near the support body 10. These sensors, along with the pressure sensors, monitor the displacement and pressure changes of the retaining wall. It should be noted that the electro-hydraulic piston device is only used to control the extension and retraction of the metal pipe; as long as this purpose is achieved, its structure is not subject to excessive restrictions.

[0051] Example 2

[0052] This embodiment provides a method for constructing a mine tunnel retaining wall as mentioned in Embodiment 1, including the following steps:

[0053] The actual measurement of the tunnel cross-section outline and dimensions determines the outline shape, height and width of the geotextile bag. Based on the maximum height of the tunnel, the number of flexible template steps and the length of each step are determined. The geotextile bag is prefabricated in advance. During the preparation process, the stiffening strip 13, reinforcing strip 12, force application component 20, pressure sensor and displacement sensor 11 are installed on the corresponding positions of the geotextile bag.

[0054] Filling grout is injected into the geotextile bags, and the grouting process is monitored in real time until the geotextile bags are fully filled and connected to the top. The reinforcing strips 13 and 12 are then tightened to fix the geotextile bags and maintain their stepped structure. The grouting rate is 0.5 m / h. The filling grout is a paste and consists of waste tailings mud from the mining area, a curing agent (cement), and water. The water content of the filling grout is 60%, and the mass ratio of the curing agent to the dry tailings mud is 1:6.

[0055] After grouting, displacement and pressure sensors are connected to monitor the displacement changes at the top of the retaining wall in real time. The pressure of the hydraulic device is dynamically adjusted through a servo mechanism until curing is completed. The wall is left to cure for more than 28 days to ensure that the grout is completely solidified, thus producing the mine tunnel retaining wall. The strength of the solidified grout is not less than 3 MPa.

[0056] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A retaining wall for filling mine tunnels, characterized in that, include: The supporting structure, part of which is a hierarchical structure, has the same overall shape as the tunnel cross-section, including an integrated flexible template and filling grout. A force-applying component for applying force to the support body includes a fixing module and a piston member. The fixing module includes two fixing plates, which are respectively disposed on two opposite sides of the support body. The piston member is disposed between the two fixing plates of the fixing module.

2. The mine tunnel retaining wall according to claim 1, characterized in that, The supporting structure is stepped, with the length of the top step being 1-1.5 m, the length difference between two adjacent steps being 1-2 m, and the height of each step being 0.8-1.2 m.

3. The mine tunnel retaining wall according to claim 1, characterized in that, The supporting body is provided with several reinforcing strips and stiffening strips at intervals.

4. The mine tunnel retaining wall according to claim 1, characterized in that, One of the fixing plates is disposed on the side of the support body that contacts the roadway cross section.

5. The mine tunnel retaining wall according to claim 1, characterized in that, The fixed plate is equipped with several pressure sensors, and the support body is equipped with several displacement sensors.

6. The mine tunnel retaining wall according to claim 1, characterized in that, The thickness of the fixing plate is 50-100 mm.

7. The mine tunnel retaining wall according to claim 3, characterized in that, The width of the stiffening strip is 20-40cm, the width of the reinforcing strip is 10-20cm, and the interval between adjacent reinforcing strips and stiffening strips is 30-40cm.

8. The mine tunnel retaining wall according to claim 1, characterized in that, The piston assembly includes a metal tube and an electro-hydraulic piston device.

9. A method for constructing a retaining wall for filling a mine tunnel according to any one of claims 1-8, characterized in that, Includes the following steps: S1. After installing the force application components, stiffening strips, reinforcing strips, pressure sensors, and displacement sensors on the flexible template, place the flexible template at the section of the roadway that needs to be filled, and fill the flexible template with grout through the grouting port on the flexible template. The grout and the flexible template together constitute the supporting body. S2. After grouting is completed, the grouting port is closed, and the force application component is used to apply pressure to the support body so that the support body abuts against the roadway cross section. S3. Allow the filling slurry to cure completely, thus obtaining the filling mine retaining wall.

10. The construction method according to claim 9, characterized in that, In step S1, the slurry injection rate is 0.5-1.0 m / h.

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