WO2023134375A1 - Large-span false roof structure using downward horizontal approach filling method, and construction method - Google Patents

Abstract

Disclosed is a large-span false roof structure of a downward horizontal approach filling method, the structure comprising a cemented filling body, a prefabricated framework, and fixing anchor rods (4), wherein the prefabricated framework comprises an arc-shaped net rack (6), rectangular net racks (5), a pre-tensile stress steel bar (3), steel bar anchor rods and a metal net (7); the arc-shaped net rack (6) is arranged at the bottom of a filling false roof and is a double-layer net rack; the pre-tensile stress steel bar (3) is welded to two ends of a lower-layer steel bar at the bottom of the arc-shaped net rack (6), and the rectangular net racks (5) are arranged on two sides of the arc-shaped net rack (6); steel bar anchor rods I (1) are welded to the rectangular net racks (5), and steel bar anchor rods II (2) are welded to the arc-shaped net rack (6); and the rectangular net racks (5) are fixed to a side wall by means of the fixing anchor rods (4), the metal net (7) is arranged on back sides of the rectangular net racks (5) and an upper portion of the pre-tensile stress steel bar (3), and the arranged prefabricated framework is filled with the cemented filling body. The structure has the advantages such as being reasonable in terms of structure, high in terms of strength, and good in terms of safety, the approach size can be effectively increased on the basis that safety is guaranteed, thereby significantly improving the mining efficiency, and the structure is particularly suitable for deep mining. Further disclosed is a construction method using the structure.

Description

A large-span false roof structure and construction method with downward horizontal approach filling method technical field

The invention relates to the technical field of mining, in particular to a large-span false roof structure and a construction method of a downward horizontal approach filling method.

Background technique

The filling method is one of the three major mining methods of metal mines at present. Especially with the improvement of safety and environmental protection requirements, the filling method has gradually become the main mining method of various metal mines, especially for gold, silver, copper and other precious metal mines. , The filling method can ensure the effective exploitation of precious metal resources.

For the mining of metal ores with high value but poor rock stability or high ground stress, the downward horizontal layering approach and filling mining method is usually adopted. The main feature of this method is to mine the upper layered ore body first, then build a false roof and fill it, and then recover the lower ore body under the protection of the false roof. Therefore, filling the false roof is the key to ensuring the mining safety of the lower ore body It is also one of the key procedures of the downward horizontal layered approach filling mining method.

The main factor determining the stability of the false roof is the strength of the filling body. Due to the limited strength of the filling body itself, it is easy to be damaged under the action of tensile stress, causing the false roof to cross. Therefore, in order to make up for the weakness of the low strength of the filling body, at present, generally refer to the production idea of reinforced concrete, arrange a certain size of metal mesh in the filling body, so as to improve the strength of the filling body, the structure of the steel mesh and its reasonable collocation with the filling body , becomes the key to the stability of the false roof filling, directly determines the stable span and height of the false roof, and then affects the overall mining efficiency. At the same time, the structural form of the steel mesh will also have a significant impact on the construction efficiency of the false roof.

At the same time, with the increase of mining depth, large-scale stope and high-efficiency mining have gradually become the main technical ideas of metal ore mining. How to effectively expand the size of the route under the premise of ensuring safety is the key to the future downward horizontal route filling method. The main direction of development.

The key to increasing the access span is to increase the strength of the filled false roof, especially the tensile strength at the bottom of the exposed false roof. At present, the main method is to increase the metal mesh structure to improve the overall strength.

For example, the prior art discloses a false roof of filling body with a built-in preset metal mesh reinforcement structure and its construction method. By arranging the side mesh, bottom mesh and vertical mesh, a metal mesh composite structure is formed, thereby improving the filling capacity. The strength of the false roof, but when this method is installed on site, it is necessary to arrange multiple fixed anchor rods on the side, the construction period is long, the structure of the combined metal mesh is complex, and the on-site assembly is difficult. In addition, this structure cannot effectively improve the route span. The prior art also discloses a method of filling a false roof with a shrinkable mesh material. This method uses 3D printing technology to produce a grid structure for on-site installation. It has the advantages of high efficiency and convenience, but the 3D printing technology is difficult. The cost is high, and this method cannot effectively increase the route span. The prior art also discloses an artificial false roof construction method based on paste filling. By adopting high-strength paste filling, carrying out steel support + wooden support, and arranging steel bars and suspension bars, the high Large-diameter deep holes are used for safe and efficient mining at the first stage, but this invention requires a large number of support constructions, resulting in slow construction efficiency of the overall false roof, and the need to arrange hanging bars and bottom bars at the same time, resulting in complicated construction.

Contents of the invention

The invention provides a downward horizontal filling method for the problems of small span of false roof, low mining efficiency, insufficient strength of filling false roof, easy crossover after exposure, complex installation and layout of metal mesh on site, and slow efficiency. Road filling method for long-span false roof structure and construction method.

The structure includes a cemented filling body, a prefabricated skeleton and a fixed anchor rod, the prefabricated skeleton is fixed on the side wall of the approach through the fixed anchor rod, and the cemented filling body fills the prefabricated skeleton;

Among them, the prefabricated skeleton includes arc-shaped grid, rectangular grid, pre-stressed steel bars, steel anchor rods and metal mesh,

The arc-shaped grid frame is placed at the bottom of the filling false roof, and the two ends of the lower long-side steel bars at the bottom of the arc-shaped grid frame are welded with pre-tensioned stress steel bars. Two welded reinforcement anchor rods are welded on the rectangular grid frame, and metal mesh is arranged on the back side of the rectangular grid frame and the upper part of the pre-tensioned stress reinforcement.

The cemented filling body is formed by the hydration and condensation of the filling slurry. The height of the cemented filling body is the height of the false roof, and the 28-day strength of the filling body is required to be ≥ 5 MPa.

The arc-shaped net frame is a double-layer net frame. The long and short sides of the arc-shaped net frame are both arc-shaped. It is made of Q235 or Q335 ribbed steel bars. The diameter of the steel bars is 12-16mm. ~400mm; the vertical distance between the highest point and the lowest point of the arc-shaped steel bars on the long side and short side of the arc-shaped grid frame is 300-500mm; the grid unit of the arc-shaped grid frame is rectangular or triangular.

The rectangular network frame is a double-layer network frame, which is made of Q235 or Q335 ribbed steel bars. The diameter of the steel bar is 12-16mm. The layer spacing of the rectangular network frame is 300-500mm. 4.0m, the width is the same as that of the curved grid; the grid unit of the rectangular grid is rectangular or triangular.

The first steel anchor and the second steel anchor are made of Q235 or Q335 ribbed steel bars, the diameter of the steel bar is 12-16mm, the length of the first steel anchor is 1.5-2.0m, and the length of the second steel anchor is 0.5-1.0m.

Reinforcement anchor rod 1 is welded perpendicular to the plane of the rectangular grid, and three reinforcement rods 2 are welded in each row on the arc grid. One of the three reinforcement anchor rods 2 is arranged vertically in the center of the arc grid, and the other two are located in the center. The two sides of the reinforcement anchor rod 2 are arranged obliquely.

The metal mesh is welded with ribbed steel bars, with a diameter of 6mm to 10mm and a mesh size of 50mm×50mm to 100mm×100mm.

The construction method of this false roof structure comprises steps as follows:

S1: According to the design span and length of the stope approach, before the end of mining, prefabricate the arc-shaped grid and rectangular grid on the ground:

Along the width direction of the arc-shaped grid frame, select one upper steel bar every 1.5-2m to arrange two steel anchor rods, and arrange two steel bar anchor rods for each upper steel bar, and arrange them respectively at 1/4, 1/2 and 3/3 of the upper steel bars. 4 places, of which 1/2 of the bolts are vertically upward, the angle between the 1/4 and 3/4 of the bolts and the horizontal is 60-75°, and the 1/4 and 3/4 of the bolts are symmetrically distributed;

Along the length direction of the rectangular network frame, arrange a steel anchor bar 1 at intervals of 1 to 1.5m, and the steel bar anchor bar 1 is perpendicular to the long side of the rectangular network frame;

S2: Before the end of mining, complete the production of pre-stressed steel bars:

According to the span of the arc-shaped grid, intercept the corresponding length, use welding to connect with the two ends of the lower steel bars of the arc-shaped grid, and arrange a pre-tensioned stress reinforcement every 1.5-2.0m in the width direction of the arc-shaped grid;

S3: Before the end of mining, arrange metal mesh on the pre-tensioned stress reinforcement of the arc-shaped grid, and connect it firmly by binding or welding. The metal mesh exceeds the short sides of the arc-shaped grid by 50-100mm; The metal mesh is arranged on the back side of the frame, and it is firmly connected by binding or welding. The metal mesh exceeds 50-100mm on both sides of the long side of the arc-shaped mesh frame;

S4: After mining, transport the assembled arc grid and rectangular grid to the vicinity of the stope. Make sure there is no obvious over-exploitation or under-exploitation, and clean up the pumice;

S5: Arrange a fixed bolt hole every 2~3m along the two sides of the access road, the diameter of the hole is 40mm, the depth is 1.5~2m, and the slope is 15~30° downward; the height of the hole is 0.5~1.0m from the bottom plate, and the fixed Anchor rods are driven into each borehole respectively, with a length of 0.5-1.0m exposed;

S6: Transport the two rectangular grids and one curved grid to the innermost side of the approach, first place the two rectangular grids on the two sides respectively, and the cantilever end of the steel anchor rod to the inner side of the approach to ensure that the grid Vertical and stable, then place the arc-shaped grid in the middle of the approach, and the two sides are in close contact with the rectangular grid, and welded to form a group of combined grids, and finally the rectangular grid on both sides and the fixed anchor welding;

Follow the same method to install from the inside of the stope to the outside in sequence, and connect each group of combined grid frames by binding or welding, and the height of each group of combined grid frames should be kept the same;

S7: After the layout is completed, start to pour the cemented filling slurry, and finally form a false roof.

The beneficial effects of above-mentioned technical scheme of the present invention are as follows:

In the above scheme, the false roof structure has the advantages of reasonable structure, high strength, and good safety. It can effectively increase the size of the access road under the premise of ensuring safety, thereby greatly improving mining efficiency, and is especially suitable for deep mining. At the same time, the metal skeleton of the present invention can be prefabricated on the ground, which can be carried out synchronously with underground mining, thereby improving the construction efficiency of the false roof.

Description of drawings

Fig. 1 is a schematic diagram of the large-span false roof structure skeleton of the downward horizontal approach filling method of the present invention;

Fig. 2 is a schematic diagram of the arc-shaped grid structure in the large-span false roof structure of the downward horizontal approach filling method of the present invention;

Fig. 3 is a schematic diagram of the rectangular grid structure in the large-span false roof structure of the downward horizontal approach filling method of the present invention;

Fig. 4 is a schematic diagram of the metal mesh structure at the bottom of the false roof in the large-span false roof structure of the downward horizontal approach filling method of the present invention;

Fig. 5 is a structure diagram of the metal mesh on the back side of the rectangular grid in the large-span false roof structure of the downward horizontal approach filling method of the present invention.

Among them: 1-reinforcement anchor rod one; 2-reinforcement anchor rod two; 3-pretensioned stress reinforcement; 4-fixed anchor rod; 5-rectangular grid; 6-arc grid; 7-metal mesh.

Detailed ways

In order to make the technical problems, technical solutions and advantages to be solved by the present invention clearer, the following will describe in detail with reference to the drawings and specific embodiments.

The invention provides a large-span false roof structure and a construction method of a downward horizontal approach filling method.

As shown in Figure 1, the false roof structure includes a cemented filling body, a prefabricated skeleton and a fixed anchor rod 4, the prefabricated skeleton is fixed on the side wall of the approach through the fixed anchor rod 4, and the cemented filling body fills the prefabricated skeleton;

Among them, the prefabricated skeleton includes arc-shaped grid frame 6, rectangular grid frame 5, pre-stressed steel bars 3, steel anchor rods and metal mesh 7, and the prefabricated grid frame is the skeleton of the false roof, which improves the strength of the overall false roof and ensures safety;

The arc-shaped network frame 6 is placed at the bottom of the filling false roof, and the two ends of the long-side steel bars on the lower layer of the arc-shaped network frame 6 are welded with pre-tensioned stress steel bars 3, and the rectangular network frame 5 is arranged on both sides of the arc-shaped network frame 6, and the rectangular network frame 5 is welded Steel bar anchor one 1, welded steel bar anchor two 2 on the arc grid 6, the back side of the rectangular grid 5 and the pretensioned stress reinforcement 3 tops are all provided with metal mesh 7.

The cemented filling body is formed by the hydration and condensation of the filling slurry. The height of the cemented filling body is the height of the false roof, and the 28-day strength of the filling body is required to be ≥ 5 MPa. The specific ratio of the cemented filling body is determined according to the mine tailings, the properties of the cementitious material and the parameters of the filling station. The height of the filling body is 1.5-3.0m.

As shown in Figure 2, the arc-shaped network frame 6 is a double-layer network frame. The long and short sides of the arc-shaped network frame 6 are both arc-shaped. It is made of Q235 or Q335 ribbed steel bars. The distance between the steel bars is 200-400mm; the vertical distance between the highest point and the lowest point of the arc-shaped steel bars on the long side and short side of the arc-shaped grid frame 6 is 300-500mm; the grid unit of the arc-shaped grid frame 6 is rectangular or triangular , the size is 500 ~ 800mm. Generally, the width of a single arc-shaped grid frame is 3-4m, and the span is 5.5-7.7m, which is determined according to the span of filling the false roof.

As shown in Figure 3, the rectangular network frame 5 is a double-layer network frame, made of Q235 or Q335 ribbed steel bars, the diameter of the steel bar is 12-16mm, the layer spacing of the rectangular network frame 5 is 300-500mm, and the height of the rectangular network frame 5 is 1.0- 1.5m, 3.0-4.0m long, and the same width as the arc grid; the grid unit of the rectangular grid is rectangular or triangular, with a size of 500-800mm.

The pre-tensioned stress steel bar is made of the same material as the grid frame, with a diameter of 16-20mm. It is pre-tensioned by the pre-tensioning method. The pre-tensioning force is 5% to 10% of the tensile yield strength of the steel bar, and the length after pre-tensioning is 5.5 ~ 7.7m, the same span as the arc grid.

The steel anchor 1 and the steel anchor 2 are made of Q235 or Q335 ribbed steel bar, the diameter of the steel bar is 12-16mm, the length of the steel anchor 1 is 1.5-2.0m, and the length of the steel anchor 2 is 0.5-1.0m.

Reinforced anchor rod 1 is welded perpendicular to the plane of rectangular network frame 5 , and three reinforced steel anchor rods 2 2 are welded in each row on arc-shaped network frame 6 . , and the other two are arranged obliquely on both sides of the central reinforcement anchor rod 2.

As shown in Figure 4 and Figure 5, the metal mesh is made of welded ribbed steel bars, with a diameter of 6mm to 10mm and a mesh size of 50mm×50mm to 100mm×100mm.

The function of the fixed anchor is that the skeleton is fixed on the side wall, and the pipe seam anchor is adopted, with a diameter of 41mm.

The construction method of this false roof structure comprises steps as follows:

S1: According to the design span and length of the stope approach, before the end of mining, prefabricate the arc grid 6 and the rectangular grid 5 on the ground:

Along the width direction of the arc-shaped network frame 6, select one upper-layer steel bar every 1.5-2m to arrange reinforcement anchor rods 2, and each upper-layer steel bar is arranged with 3 steel-bar anchor rods 2, which are respectively arranged at 1/4 and 1/4 of the upper layer of steel bars. 2 and 3/4, of which 1/2 anchors are vertically upward, 1/4 and 3/4 anchors have an angle of 60-75° with the horizontal, and 1/4 and 3/4 anchors are symmetrically distributed;

Along the length direction of the rectangular network frame 5, arrange a reinforced anchor rod 1 at intervals of 1 to 1.5m, and the reinforced anchor rod 1 is perpendicular to the long side of the rectangular network frame;

Wherein, the connection modes of steel anchor rod one 1 and steel reinforcement anchor rod two 2 to the network frame are welding.

S2: Before the end of mining, complete the production of pre-stressed steel bars 3:

According to the span of the arc-shaped grid 6, the corresponding length is intercepted, and the two ends of the steel bars on the lower layer of the arc-shaped grid are connected by welding, and a pre-tensioned stress reinforcement 3 is arranged every 1.5-2.0m in the width direction of the arc-shaped grid;

S3: Before the mining is completed, arrange metal mesh 7 on the pre-tensioned steel bars 3 of the arc-shaped grid 6, and connect them firmly by binding or welding. The metal mesh 7 exceeds the short sides of the arc-shaped grid 6 by 50~ 100mm; the metal mesh 7 is arranged on the back side of the rectangular grid frame 5, which is firmly connected by binding or welding, and the metal mesh exceeds the two sides of the long side of the arc-shaped grid frame by 50-100 mm;

S4: After mining, transport the assembled arc-shaped grid 6 and rectangular grid 5 to the vicinity of the stope. At the same time, clean the floor and the two sides of the stope to ensure that the floor is flat, without obvious protrusions, and without water accumulation , the two gangs had no obvious over-mining and under-mining, and the pumice was cleaned up;

S5: Arrange a fixed bolt hole every 2~3m along the two sides of the access road, the diameter of the hole is 40mm, the depth is 1.5~2m, and the slope is 15~30° downward; the height of the hole is 0.5~1.0m from the bottom plate, and the fixed Anchor rods 4 are driven into each borehole respectively, and the length of 0.5-1.0m is exposed;

S6: Transport two rectangular net frames 5 and one arc-shaped net frame 6 to the innermost side of the approach, first place the two rectangular net frames 5 on the two sides respectively, and the cantilever end of the steel anchor bar-1 faces the innermost side of the approach , to ensure that the network frame is vertical and stable, then place the arc-shaped network frame 6 in the middle of the approach, and the two sides are in close contact with the rectangular network frame 5 respectively, and welded to form a group of combined network frames, and finally the rectangular network frames on both sides Frame 5 is welded with fixed anchor rod 4;

Follow the same method to install from the inside of the stope to the outside in sequence, and connect each group of combined grid frames by binding or welding, and the height of each group of combined grid frames should be kept the same;

S7: After the layout is completed, start to pour the cemented filling slurry, and finally form a false roof.

For the above-mentioned structure, for the upward horizontal layered approach filling method, the bottom of the filling false roof mainly bears the effect of tension, and the filling body is a brittle material with extremely low tensile strength. False roof safety is of paramount importance. By adopting the arc-shaped grid structure at the bottom of the filling false roof, compared with the horizontal arrangement of metal vertical and horizontal nets, the tensile strength of the bottom of the filling body can be greatly improved, so that the stability of the filling body can be ensured while increasing the span of the false roof. In addition, the pre-tensioned stress reinforcement is arranged in the lower reinforcement of the arc-shaped network frame, which further enhances the overall tensile strength.

The steel bars on the upper layer of the arc-shaped network frame of the present invention are respectively arranged with three steel bar anchors, one is vertically arranged in the center, and two are arranged obliquely on both sides. When the roof connection is exposed, the false roof will settle downward under the action of the overlying load. , causing the grid frame to deform downward. At this time, the grid frame drives the inclined anchor rods on both sides to move to the central disposal anchor rod, so that the filling body between them is squeezed, which can effectively improve the strength of the filling body in this part and prevent collapse. .

Rectangular net frames are arranged on both sides, and steel anchors facing the inside of the stope are arranged on the top. After connecting with the arc-shaped grid frames, an integral metal skeleton is formed to ensure the stability of the filling body on both sides. At the same time, the overall metal skeleton Play the role of suspension to ensure the safety of the structure.

The metal mesh laid on the top of the pre-tensioned steel bars can effectively support the false roof to ensure that the surface filling body does not collapse after the false roof is exposed; the metal mesh laid on the back of the rectangular grid frame on both sides, It can ensure that the filling bodies on both sides will not collapse after being exposed, causing loss and dilution of ore.

The above description is a preferred embodiment of the present invention, it should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, some improvements and modifications can also be made, these improvements and modifications It should also be regarded as the protection scope of the present invention.

Claims (8)

1. A large-span false roof structure with downward horizontal approach filling method, which is characterized in that it includes a cemented filling body, a prefabricated skeleton and a fixed anchor rod, the prefabricated skeleton is fixed on the side wall of the approach through the fixed anchor rod, and the cemented filling body is opposite to the prefabricated The skeleton is filled;

   Among them, the prefabricated skeleton includes arc-shaped grid, rectangular grid, pre-stressed steel bars, steel anchor rods and metal mesh,

   The arc-shaped grid frame is placed at the bottom of the filling false roof, and the two ends of the lower long-side steel bars at the bottom of the arc-shaped grid frame are welded with pre-tensioned stress steel bars. Two welded reinforcement anchor rods are welded on the rectangular grid frame, and metal mesh is arranged on the back side of the rectangular grid frame and the upper part of the pre-tensioned stress reinforcement.
2. The large-span false roof structure according to claim 1, characterized in that the cemented filling body is formed by hydration and condensation of filling slurry, and the height of the cemented filling body is the height of the false roof. 28 days strength ≥ 5MPa.
3. The large-span false roof structure according to claim 1, wherein the arc-shaped network frame is a double-layer network frame, and the long sides and short sides of the arc-shaped network frame are arc-shaped , made of Q235 or Q335 ribbed steel bar, the diameter of the steel bar is 12-16mm, and the distance between the two layers of arc-shaped steel bars is 200-400mm; The vertical distance is 300-500mm; the grid unit of the arc grid is rectangular or triangular.
4. The large-span false roof structure according to claim 1, characterized in that the rectangular grid is a double-layer grid made of Q235 or Q335 ribbed steel bars with a diameter of 12-16mm. The layer spacing of the rectangular network frame is 300-500mm, the height of the rectangular network frame is 1.0-1.5m, the length is 3.0-4.0m, and the width is the same as that of the arc-shaped network frame; the grid unit of the rectangular network frame is rectangular or triangular.
5. The large-span false roof structure according to claim 1, characterized in that, the first steel anchor and the second steel anchor are made of Q235 or Q335 ribbed steel bars with a diameter of 12-16mm. The first length of the steel anchor is 1.5-2.0m, and the second length of the steel anchor is 0.5-1.0m.
6. The large-span false roof structure according to claim 1, wherein the steel bar anchors are welded perpendicular to the plane of the rectangular grid, and three steel bar anchors are welded in each row on the arc-shaped grid. Two, one of the three steel anchor rods is arranged vertically in the center of the arc grid, and the other two are arranged obliquely on both sides of the central steel anchor rod two.
7. The large-span false roof structure according to claim 1, wherein the metal mesh is welded with ribbed steel bars, the diameter is 6mm-10mm, and the mesh degree is 50mm×50mm-100mm× 100mm.
8. The construction method of the large-span false roof structure according to the downward horizontal approach filling method according to claim 1, characterized in that it comprises the following steps:

   S1: According to the design span and length of the stope approach, before the end of mining, prefabricate the arc-shaped grid and rectangular grid on the ground:

   Along the width direction of the arc-shaped grid frame, select one upper steel bar every 1.5-2m to arrange two steel anchor rods, and arrange two steel bar anchor rods for each upper steel bar, and arrange them respectively at 1/4, 1/2 and 3/3 of the upper steel bars. 4 places, of which 1/2 of the bolts are vertically upward, the angle between the 1/4 and 3/4 of the bolts and the horizontal is 60-75°, and the 1/4 and 3/4 of the bolts are symmetrically distributed;

   Along the length direction of the rectangular network frame, arrange a steel anchor bar 1 at intervals of 1 to 1.5m, and the steel bar anchor bar 1 is perpendicular to the long side of the rectangular network frame;

   S2: Before the end of mining, complete the production of pre-stressed steel bars:

   According to the span of the arc-shaped grid, intercept the corresponding length, use welding to connect with the two ends of the lower steel bars of the arc-shaped grid, and arrange a pre-tensioned stress reinforcement every 1.5-2.0m in the width direction of the arc-shaped grid;

   S3: Before the end of mining, arrange metal mesh on the pre-tensioned steel bars, and connect them firmly by binding or welding. The metal mesh exceeds 50-100mm on both sides of the short side of the curved grid; The net is firmly connected by binding or welding, and the metal net is 50-100mm beyond the long sides of the arc-shaped net frame;

   S4: After mining, transport the assembled arc grid and rectangular grid to the vicinity of the stope. Make sure there is no obvious over-exploitation or under-exploitation, and clean up the pumice;

   S5: Arrange a fixed bolt hole every 2~3m along the two sides of the access road, the diameter of the hole is 40mm, the depth is 1.5~2m, and the slope is 15~30° downward; the height of the hole is 0.5~1.0m from the bottom plate, and the fixed Anchor rods are driven into each borehole respectively, with a length of 0.5-1.0m exposed;

   S6: Transport the two rectangular grids and one curved grid to the innermost side of the approach, first place the two rectangular grids on the two sides respectively, and the cantilever end of the steel anchor rod to the inner side of the approach to ensure that the grid Vertical and stable, then place the arc-shaped grid frame in the middle of the approach, and the two sides are in close contact with the rectangular grid frame, and welded to form a group of combined grid frames, and finally the rectangular grid frames on both sides are connected with the fixed anchor rods. welding;

   Follow the same method to install from the inside of the stope to the outside in sequence, and connect each group of combined grid frames by binding or welding, and the height of each group of combined grid frames should be kept the same;

   S7: After the layout is completed, start to pour the cemented filling slurry, and finally form a false roof.

Images