Simulation method for fluidized grouting in old goaf roadways

Abstract

The present invention discloses a method for simulating fluidized grouting in old goaf roadways, which relates to the technical field of the repair and treatment of old goafs in mines. The method includes: First, in combination with the actual geological situation, determine the location of the roadway to be grouted, and use a geological radar with a large penetration depth to scan directly above the roadway to understand the morphological characteristics of the roadway and the internal collapse situation; Then, in the test box of the simulation equipment, according to the radar scanning results, simulate the internal morphology of the roadway by changing the depth of the limiting rod inserted into the test box. After that, use crushed gangue to simulate the accumulation of crushed stones inside the roadway; Finally, further optimize the grouting plan based on the data obtained by the speed detector and the fiber optic sensor. The method of the present invention can provide a certain theoretical basis for on-site construction, reduce the on-site construction trial-and-error cost, and can more intuitively observe the situation of the slurry injected into the old goaf.

Description

Technical Field

[0001] The present invention relates to the technical field of repair and treatment of old mined - out areas in mines, and particularly to a simulation method for fluidized grouting in old mined - out area roadways. Background Art

[0002] After coal resources are mined, old mined - out areas are formed underground. The generation and existence of such bad geological bodies pose a serious threat to the safe construction and stable operation of surface buildings (structures). A coal - mining subsidence area refers to an area where the surface subsidence depth caused by coal mining is greater than 10 mm. The agricultural land with reduced or no production and the affected construction land and unused land in the coal - mining subsidence area due to underground coal mining are called coal - mining subsidence land. At present, problems such as limited space for the transformation and development of most mining cities and insufficient construction land are becoming increasingly prominent. There is an urgent need to carry out the construction and utilization of coal - mining subsidence land to ensure the supply of urban construction land and promote the transformation and development of cities.

[0003] Currently, when repairing and treating old mined - out areas, grouting filling, as one of the treatment methods, can effectively control the subsidence area after grouting filling the mined - out area. However, the existing methods in the prior art cannot effectively estimate the diffusion area of the grout injected into the old mined - out area and the grout injection points. If too much grout is injected, it will cause waste of grout, while if too little grout is injected, the rock strength in the subsidence area will be weak. Especially for old mined - out areas and closed - pit coal mines, due to the inability to obtain the specific conditions inside the roadway, it is impossible to determine the grouting position and the specific flow state parameters of the grout flow inside the roadway. Therefore, it seriously affects the secondary development and utilization of the subsidence area and restricts the progress of the comprehensive management of mines. Summary of the Invention

[0004] The purpose of the present invention is to provide a simulation method for fluidized grouting in old mined - out area roadways. Through small - scale experimental simulations and combined with the actual geological situation, the grouting situation can be observed and analyzed, the grouting position and the specific flow state parameters of the grout flow inside the roadway can be determined, providing a certain reference basis for on - site construction.

[0005] To achieve the above - mentioned purpose, the present invention adopts the following technical solutions:

[0006] A simulation method for fluidized grouting in old mined - out area roadways successively includes the following steps:

[0007] a. Combining the actual geological situation, determine the position of the roadway to be grouted, and understand the morphological characteristics and internal collapse situation of the actual roadway by scanning directly above the roadway;

[0008] b. On the premise of understanding the morphological characteristics and internal collapse conditions of the actual roadway, prepare a simulation device. The simulation device includes a base and a box body located on the base. Construct a simulated roadway structure on the base. The simulated roadway structure includes a roof and side plates on both sides of the roof. The roof is made of wire mesh, and the side plates are made of transparent acrylic plates.

[0009] c. Lay a speed detector and an optical fiber sensor on the bottom plate of the simulated roadway structure. Lay similar simulation material b around the simulated roadway structure. The similar simulation material b is gangue particles. Lay similar simulation material a on the top surface of the simulated roadway structure and above the similar simulation material b. The similar simulation material a is composed of gangue particles, lime, gypsum and water. The total height of the similar simulation material a and the similar simulation material b is less than the height of the box body.

[0010] d. Arrange a number of limiting rods in the box body. The number of limiting rods is closely arranged together along the length direction of the box body. The bottom end of each limiting rod is inserted into the similar simulation material a or the similar simulation material b. The insertion depth of each limiting rod can be adjusted. By changing the insertion depth of the limiting rod, the internal morphology of the roadway is simulated.

[0011] e. After the simulated roadway structure is determined, quickly withdraw the side plates of the simulated roadway structure. The crushed stones in the similar simulation material b outside the side plates accumulate towards the inside of the simulated roadway, thereby simulating the natural accumulation of broken rocks in the roadway.

[0012] f. Arrange a grouting mechanism. The grouting mechanism includes a grouting hard pipe, a grouting soft pipe, a jaw crusher, a jaw grinder and a stirrer. The grouting hard pipe passes through the similar simulation material to the roof of the simulated roadway structure. The top end of the grouting hard pipe is connected to the grouting soft pipe. The grouting soft pipe is connected to the outlet end of the stirrer. The jaw crusher, the jaw grinder and the stirrer are connected in sequence. Prepare a fluidized test slurry through the grouting mechanism and inject it into the simulated roadway through the grouting soft pipe and the grouting hard pipe.

[0013] g. Analyze the grouting situation of the fluidized slurry according to the data obtained by the speed detector and the optical fiber sensor, and combine with the situation observed in step e. After the slurry is consolidated, disassemble the model and observe and analyze the grouting situation.

[0014] As a preferred solution of the present invention, in step b, the mesh size of the wire mesh is 3 cm × 3 cm; the thickness of the transparent acrylic plate is 2 cm, and the box body is also made of transparent acrylic plate. The thickness of the transparent acrylic plate constituting the box body is 5 cm.

[0015] As another preferred solution of the present invention, in step c, according to the mass ratio, the ratio of gangue particles, lime, gypsum and water is 8:1:1:1 in sequence.

[0016] Preferably, the limiting rod is made of PVC plastic, with a length of 50-100 cm and a diameter of 2 cm.

[0017] Preferably, the grinding particle size of the waste rock after passing through the jaw grinder is <0.5 mm.

[0018] Preferably, a pressure pump is arranged below the stirrer, and the grouting hose is connected to the pressure pump.

[0019] Compared with the prior art, the present invention brings the following beneficial technical effects:

[0020] The present invention proposes a method for simulating fluidized grouting in old goaf roadways. By simulating the cooperation of roadway structure, similar simulation materials, limiting rods, fiber optic sensors, speedometers and grouting mechanisms, the simulation research on the internal morphological characteristics and internal collapse conditions of the roadway can be carried out; by setting transparent acrylic plates, it is convenient to observe the internal morphology of the roadway.

[0021] The method for simulating fluidized grouting in old goaf roadways provided by the present invention can provide a certain theoretical basis for on-site construction and reduce the on-site construction trial-and-error cost; it can more intuitively observe the situation of slurry injection into the old goaf.

[0022] In summary, the present invention first combines the actual geological situation to determine the location of the roadway to be grouted, uses a geological radar with a large penetration depth to scan directly above the roadway to understand the morphological characteristics and internal collapse conditions of the roadway. Then, in the test box of the simulation equipment, according to the radar scan results, the internal morphology of the roadway is simulated by changing the insertion depth of the limiting rod in the test box. Then, the accumulation of crushed rock in the roadway is simulated using crushed gangue, and finally, the grouting plan is further optimized based on the data obtained by the speedometer and fiber optic sensors. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The following further describes the present invention with reference to the drawings:

[0024] Figure 1 Shows the natural accumulation diagram of gangue in the old goaf roadway;

[0025] Figure 2 Shows the initial state diagram of the roadway;

[0026] Figure 3 , Figure 4 , Figure 5 Shows the deformation state of the roadway with the limiting rod inserted at different depths;

[0027] Figure 6 Is the structural schematic diagram of the grouting device adopted by the method of the present invention;

[0028] In the figure:

[0029] 1. Jaw crusher, 2. O-type grinding instrument, 3. Stirrer, 4. Pressure pump, 5. Box shell, 6. Similar simulation material a, 7. Top plate, 8. Base, 9. Limit rod, 10. Grouting hose, 11. Grouting hard pipe, 12. Similar simulation material b, 13. Side plate, 14. Fiber optic sensor, 15. Speedometer. Specific implementation mode

[0030] The present invention provides a method for simulating fluidized grouting in old goaf roadways. In order to make the advantages and technical solutions of the present invention clearer and more definite, the following further describes the present invention with specific embodiments.

[0031] As Figure 6 shown, the device adopted by the method for simulating fluidized grouting in old goaf roadways of the present invention includes a jaw crusher 1, an O-type grinding instrument 2, a stirrer 3, a pressure pump 4, a box shell 5, a similar simulation material a 6, a top plate 7, a base 8, a limit rod 9, a grouting hose 10, a grouting hard pipe 11, a similar simulation material b 12, a side plate 13, a fiber optic sensor 14 and a speedometer 15.

[0032] Among them, the jaw crusher 1 is sequentially connected to the O-type grinding instrument 2 and the stirrer 3. The waste rock is ground in the jaw crusher 1 and the O-type grinding instrument 2, and the particle size after grinding is less than 0.5 mm. The ground waste rock enters the stirrer 3 and is mixed with other materials. A pressure pump 4 is arranged below the stirrer 3. Under the action of the pressure pump, the uniformly mixed slurry enters the grouting hose 10 and then enters the grouting hard pipe 11 connected thereto after passing through the grouting hose 10.

[0033] The above-mentioned grouting hose 10 and grouting hard pipe 11 are located inside the box shell 5, and the jaw crusher 1, the O-type grinding instrument 2 and the stirrer 3 are located above the box shell 5. The shape of the box shell 5 is preferably rectangular. In order to facilitate observing the internal shape of the roadway, the box shell is preferably made of transparent acrylic board, and the thickness of the acrylic board is 5 cm.

[0034] The box shell 5 and the base 8 are combined to form a sealed structure. A simulated roadway structure is constructed inside the sealed structure. The shape of the simulated roadway structure is preferably arched, including a top plate and side plates on both sides of the top plate. Among them, the top plate is made of wire mesh, and the mesh size of the wire mesh is 3 cm × 3 cm. The side plates are made of transparent acrylic board, and the thickness of the acrylic board is 2 cm.

[0035] After the above-mentioned simulated roadway structure is constructed, fiber optic sensors 14 and speed detectors 15 are arranged at the bottom of the roadway to facilitate the measurement of the morphological characteristics of the roadway. In addition, similar simulation material b is laid around the simulated roadway structure. The similar simulation material b is gangue particles. Similar simulation material a is laid above the similar simulation material b. The similar simulation material a is composed of gangue particles, lime, gypsum, and water. According to the mass ratio, the proportion is 8:1:1:1 in sequence.

[0036] In order to more realistically simulate the morphology inside the roadway, the present invention creatively introduces a limiting rod into the present invention. The limiting rod is inserted into the similar simulation material b or the similar simulation material a in a row. There is no gap between adjacent limiting rods, and they are arranged closely together. Preferably, the limiting rods are arranged in the length direction of the box body, and the insertion depth of each limiting rod is adjustable. By adjusting the insertion depth of each limiting rod, the morphology inside the roadway is simulated.

[0037] The following mainly describes the fluidized grouting simulation method for the roadway in the old goaf of the present invention, which specifically includes the following steps:

[0038] Step 1: Combine the actual geological situation to determine the location of the roadway to be grouted, and understand the morphological characteristics and internal collapse situation of the actual roadway by scanning directly above the roadway.

[0039] Step 2: On the premise of understanding the morphological characteristics and internal collapse situation of the actual roadway, prepare a simulation device. The simulation device includes a base and a box body located on the base. A simulated roadway structure is constructed on the base. The simulated roadway structure includes a roof and side plates located on both sides of the roof. The roof is made of wire mesh, and the side plates are made of transparent acrylic plates.

[0040] Step 3: Lay speed detectors and fiber optic sensors on the bottom plate of the simulated roadway structure, lay similar simulation material b around the simulated roadway structure. The similar simulation material b is gangue particles; lay similar simulation material a on the top surface of the simulated roadway structure and above the similar simulation material b. The similar simulation material a is composed of gangue particles, lime, gypsum, and water. The total height of the similar simulation material a and the similar simulation material b is less than the height of the box body.

[0041] Step 4: Arrange a number of limiting rods in the box body. The number of limiting rods is arranged closely together along the length direction of the box body, and the bottom end of each limiting rod is inserted into the similar simulation material a or the similar simulation material b. The insertion depth of each limiting rod is adjustable. By changing the insertion depth of the limiting rod, the morphology inside the roadway is simulated.

[0042] Step 5: After the simulated roadway structure is determined, quickly remove the side plates of the simulated roadway structure. The gravel in the similar simulation material b outside the side plates accumulates towards the inside of the simulated roadway, thereby simulating the natural accumulation of broken rocks in the roadway.

[0043] Step 6: Arrange the grouting mechanism. The grouting mechanism includes a grouting hard pipe, a grouting flexible pipe, a jaw crusher, a jaw grinder, and a stirrer. The grouting hard pipe passes through the similar simulation material to the roof of the simulated roadway structure. The top end of the grouting hard pipe is connected to the grouting flexible pipe, and the grouting flexible pipe is connected to the outlet end of the stirrer. The jaw crusher, the jaw grinder, and the stirrer are connected in sequence. Prepare the fluidized test slurry through the grouting mechanism and inject it into the simulated roadway through the grouting flexible pipe and the grouting hard pipe.

[0044] Step 7: Analyze the grouting situation of the fluidized slurry according to the data obtained by the speedometer and the fiber optic sensor, and in combination with the situation observed in step e. After the slurry consolidates, disassemble the model and observe and analyze the grouting situation.

[0045] The following further illustrates the present invention with specific embodiments.

[0046] Embodiment 1:

[0047] Using the simulation method of the present invention, this embodiment shows the natural accumulation of gangue in the roadway of the old goaf, as Figure 1 shown. It can be seen from Figure 1 that there is natural accumulation of gangue in the roadway of the old goaf. Using the simulation method of the present invention, the grouting position and the specific flow state parameters of the slurry flow inside the roadway can be determined, providing certain reference for on-site construction.

[0048] Embodiment 2:

[0049] Using the simulation method of the present invention, this embodiment shows the deformation state of the roadway in the old goaf over time. It mainly studies the influence of the deformation of the roadway by changing the insertion depth of the limit rods. As Figure 2 shows the initial state diagram of the roadway. In Figure 2 all the limit rods have the same insertion depth and are inserted on the roof of the roadway; Figure 3 shows the initial deformation state diagram of the roadway. It can be seen from Figure 3 that by changing the insertion depth of the limit rods, the insertion depth of the limit rods in the middle part is greater than that of the limit rods on both sides, and the roadway deformation is as Figure 3 shown. After further changing the insertion depth of the limit rods, the roadway deformation is as Figure 4 shown. Finally, by changing the insertion depth of the limit rods, the final deformation of the roadway is as Figure 5 shown.

[0050] Under the guidance of the present invention, those skilled in the art can further conduct relevant research on pastes, paste-like materials, water-sand cementitious materials, etc.

[0051] The parts not described in the present invention can be realized by adopting or referring to the existing technologies.

[0052] It should be further noted that the specific embodiments described herein are merely illustrative of the spirit of the present invention. Those skilled in the art to which the present invention pertains can make various modifications or supplements to the described specific embodiments or use similar ways of substitution, but will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. A simulation method for fluidized grouting in old goaf roadways, characterized in that, it successively includes the following steps: Step a: Combining the actual geological situation, determine the location of the roadway to be grouted, and understand the actual roadway morphological characteristics and internal collapse conditions by scanning directly above the roadway; Step b: On the premise of understanding the actual roadway morphological characteristics and internal collapse conditions, prepare a simulation device. The simulation device includes a base and a box body located on the base. Construct a simulated roadway structure on the base. The simulated roadway structure includes a roof and side plates on both sides of the roof. The roof is made of wire mesh, and the side plates are made of transparent acrylic plates; Step c: Lay a speed detector and fiber optic sensors on the bottom plate of the simulated roadway structure, and lay similar simulation material b around the simulated roadway structure. The similar simulation material b is gangue particles; Lay similar simulation material a on the top surface of the simulated roadway structure and above the similar simulation material b. The similar simulation material a is composed of gangue particles, lime, gypsum and water. The total height of the similar simulation material a and the similar simulation material b is less than the height of the box body; Step d: Arrange a number of limiting rods in the box body. The number of limiting rods are closely arranged along the length direction of the box body, and the bottom end of each limiting rod is inserted into the similar simulation material a or the similar simulation material b. The insertion depth of each limiting rod is adjustable, and the internal morphology of the roadway is simulated by changing the insertion depth of the limiting rod; Step e: After the simulated roadway structure is determined, quickly remove the side plates of the simulated roadway structure. The crushed stones in the similar simulation material b outside the side plates accumulate towards the inside of the simulated roadway, thereby simulating the natural accumulation of broken rocks in the roadway; Step f: Arrange a grouting mechanism. The grouting mechanism includes a grouting hard pipe, a grouting flexible pipe, a jaw crusher, a jaw grinding instrument and a stirrer. The grouting hard pipe passes through the similar simulation material to the roof of the simulated roadway structure. The top end of the grouting hard pipe is connected to the grouting flexible pipe. The grouting flexible pipe is connected to the outlet end of the stirrer. The jaw crusher, the jaw grinding instrument and the stirrer are connected in sequence; Prepare fluidized test slurry through the grouting mechanism, and inject it into the simulated roadway through the grouting flexible pipe and the grouting hard pipe; Step g: Analyze the fluidized slurry grouting situation according to the data obtained by the speed detector and the fiber optic sensors, and combine with the situation observed in Step e. After the slurry consolidates, disassemble the model and observe and analyze the grouting situation.

2. A simulation method for fluidized grouting in old goaf roadways according to claim 1, characterized in that: In Step b, the mesh size of the wire mesh is 3 cm × 3 cm; the thickness of the transparent acrylic plate is 2 cm, and the box body is also made of transparent acrylic plate. The thickness of the transparent acrylic plate constituting the box body is 5 cm.

3. A simulation method for fluidized grouting in old goaf roadways according to claim 1, characterized in that: In Step c, according to the mass ratio, the ratio of gangue particles, lime, gypsum and water is 8:1:1:1 in sequence.

4. A simulation method for fluidized grouting in old goaf roadways according to claim 1, characterized in that: The limiting rod is made of PVC plastic, with a length of 50 - 100 cm and a diameter of 2 cm.

5. A method for simulating fluidized grouting in old goaf roadways according to claim 1, characterized in that: the grinding particle size of the waste rock after passing through the jaw grinder is < 0.5 mm.

6. A method for simulating fluidized grouting in old goaf roadways according to claim 1, characterized in that: a pressure pump is arranged below the stirrer, and the grouting hose is connected to the pressure pump.

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