Temporary support wall type movable formwork for pouring underground filling body and use method

Abstract

The present invention discloses a temporary support wall-type mobile formwork for pouring underground filling bodies and a method for using the formwork, wherein the formwork is composed of a formwork portion and a triangular support portion; the formwork portion is a composite steel formwork, which includes a panel, a horizontal frame, and a vertical frame, and the panel is provided with horizontal ribs, vertical ribs, and back ribs, respectively; the triangular support portion is composed of several triangular supports, which are connected by steel pipes and fixed to the triangular supports by steel pipe fasteners; a single triangular support is composed of a triangular truss made of double No. 10 channel steel and double No. 14 channel steel, the bottom of the triangular truss is provided with a lifting and supporting device and a sliding device, and the top is provided with a temporary support device; the formwork portion and the triangular support portion are connected and fixed by double No. 10 channel steel. On the one hand, the present invention can enhance the strength of the filling body and reduce the compression of the filling body; on the other hand, it can realize temporary support of the top plate and form a combined bearing structure of top plate-temporary support device-floor collaborative bearing.

Description

Technical Field

[0001] The invention relates to a temporary support wall type movable template for pouring an underground filling body and a use method thereof, belonging to the technical field of filling mining. Background Art

[0002] Coal, as my country's primary energy source, has long made indelible contributions to national economic and social development. Traditional coal mining methods, such as caving, can cause widespread deformation and collapse of overlying rock, surface subsidence and structural instability, groundwater system imbalance, irregular gas accumulation in goafs, and spontaneous combustion of residual coal, among other environmental and safety issues. The accumulation of coal gangue and other coal mine solid waste also contributes significantly to land occupation and environmental pollution. While backfill mining, a key development direction for green mining currently being advocated, can undoubtedly mitigate these issues, many mining areas face increasing resource depletion, yet still harbor significant amounts of residual coal resources, including those from coal "under three-down" pressure. Compared to traditional mining methods and full-mining and full-filling methods, partial backfilling in goafs offers numerous advantages, including eliminating the need for extensive coal pillars, achieving high coal recovery rates, protecting the ecological environment, requiring relatively small amounts of backfill space, reducing the workload and material usage, and lowering backfill costs.

[0003] The partial filling methods of goaf mainly include strip-type partial filling and pier-type partial filling. The temporary support wall-type mobile formwork that can be raised, lowered, disassembled and slid for pouring underground filling body is mainly used for strip-type partial filling, and pier-type partial filling can also be considered for use. Summary of the Invention

[0004] The present invention aims to provide a temporary support wall type movable formwork for pouring underground filling bodies, which is liftable, detachable and slidable. The present invention also provides a method for using the movable formwork.

[0005] The present invention provides a temporary retaining wall-type mobile formwork for pouring underground filling bodies, which consists of a formwork portion and a triangular support portion. The main body of the formwork portion is a composite steel formwork, which includes a panel, a horizontal frame, and a vertical frame. The panel is provided with horizontal ribs, vertical ribs, and back ribs, respectively. The various components of the composite steel formwork are fixed together by bolts. A flexible formwork material, PVC-coated cloth (made of nylon), is provided above the composite formwork. The bottom edge of the PVC-coated cloth is placed on the horizontal frame above the composite steel formwork, and wooden strips of the same width as the horizontal frame are placed on it. The horizontal frame above the composite steel formwork, the PVC-coated cloth, and the wooden strips are fixed together by bolts, thus forming the entire formwork portion. The formwork portion and the triangular support portion are connected and fixed by double-number ten channel steels, and the triangular support portion is fixed to the channel steel back rib fasteners by channel steel back rib fasteners. The triangular support section is composed of several triangular supports, depending on the specific situation. The triangular supports are connected by steel pipes and fixed to the triangular supports with steel pipe fasteners. A single triangular support is composed of a pair of No. 10 channel steel and a pair of No. 14 channel steel to form a triangular truss. The bottom of the triangular truss is equipped with a lifting and supporting device and a sliding device, and the top is equipped with a temporary support device. One side of the back rib is welded to the longitudinal rib of the formwork, and the other side is connected to the double No. 14 channel steel of the triangular support section with a back rib fastener.

[0006] This formwork not only enhances the strength of the filling and reduces its compression, but also provides temporary support for the roof, forming a combined load-bearing structure comprised of roof, temporary support, and floor. During strip filling, wall-type movable formwork can be symmetrically arranged on both sides to create the filling space for the strip. Water-stopping tie rods are placed on the formwork panels to secure the two sides and provide the majority of lateral support during filling, enhancing the stability of the filling and formwork.

[0007] In the above scheme, the composite steel formwork is 800mm long, 600mm high, and 5mm thick, made of Q235 steel plate. It consists of a faceplate, horizontal frames, and vertical frames. The faceplate, which contacts the filling, is evenly distributed with horizontal and vertical ribs. The horizontal ribs are made of Q235 steel plate, the vertical ribs are made of No. 8 channel steel, and the back ribs are made of double No. 10 channel steel. The horizontal and vertical ribs are welded to the back of the faceplate (i.e., the other side of the filling), and the back ribs are welded to the vertical ribs. Bolt holes are evenly distributed on the horizontal and vertical frames.

[0008] In the above scheme, the back ribs and triangular supports are connected as follows: Channel back rib fasteners are used at the intersection of each cross rib and double 14 channel on one side of the double 10 channel steel. At the same time, the formwork back ribs of the double 10 channel steel are connected with core straps between each two adjacent formwork panels and reinforced with core strap pins, ensuring a tighter and more secure connection between the formwork and triangular supports. When fasteners are inconvenient, butt bolts can be used for connection.

[0009] In the above scheme, two adjacent composite steel formworks are fixed with M16 bolts and corresponding nuts and washers. The diameter of the M16 bolt is 16mm, the length is 60mm, the thickness of the nut is 15.9mm, the average thickness is 3mm, and the gasket is 4.1mm. The horizontal frame, PVC coated cloth and wooden strips above the composite steel formwork are also fixed with M16 bolts.

[0010] In the above scheme, the triangular support is welded from double No. 14 and double No. 10 channel steels. The double No. 14 channel steel is used on the main facade, and is paired with the double No. 10 channel steel to form a triangular stable structure. The length and width of the triangular frame of the triangular support are determined according to the specific conditions of the filling work surface and the size of the formwork. The double No. 14 channel steel should extend upward 200mm to 300mm relative to the triangular frame.

[0011] In the above scheme, the filling port is set at the top of the formwork, determined based on the height of the filler to be filled. The filler can generally be inserted from a point close to the roof, or the filling port can be set at a fixed position on the formwork. Without a specific filling port, the end of the filling pipe can be suspended from the roof of the area to be filled, and the hanging position on the roof can be adjusted as needed. In actual use, the end of the filling pipe is pre-suspended on the roof of the area to be filled, and then the single hydraulic support on the upper part of the triangular support is raised, carrying the PVC coating cloth. The PVC coating cloth installed on the upper part of the formwork is deformable, and in the area where the end of the filling pipe is located, it adheres closely to the outer wall of the pipe. In other areas, the PVC coating cloth can be carried by the hydraulic support to close to the roof.

[0012] In the above scheme, a lifting and supporting device is installed at the bottom of the triangular support. It consists of a threaded sleeve, lifting screw, and bottom plate support plate. The threaded sleeve and lifting screw are made of Q45 steel, and the bottom plate support plate is made of Q235 steel. A sliding device is installed at the bottom of the triangular support. The sliding device consists of a threaded sleeve, lifting screw, and universal casters. The threaded sleeve and lifting screw are made of Q45 steel, and the universal casters are made of No. 45 steel, with a wheel diameter of 50 mm and a wheel width of 32 mm, and can carry a load of 160 kg. On the one hand, the lifting and supporting device at the bottom of the triangular support, the double No. 14 channel steel, and the temporary support device at the top form a combined load-bearing structure of top plate, temporary support device, and floor. On the other hand, the template height is controlled by adjusting the lifting screw to adapt to the bottom plate at a certain tilt angle. During filling, the adjustable lifting device, i.e., a lifting screw equipped with a threaded sleeve, can, on the one hand, allow the template to freely change in height within a certain range; on the other hand, it can allow the template to have the same inclination angle as the base plate, so that the bottom of the template fits tightly with the base plate. If necessary, a sponge strip can be placed between the bottom of the template and the base plate to prevent leakage, so that the filling area is tightly sealed to prevent the filling slurry from leaking into the filling area.

[0013] A single hydraulic support and a supporting plate are set on the top of the triangular support to temporarily support the top plate; the supporting plate is placed on the single hydraulic support, and the bottom of the supporting plate has a groove that adapts to the upper part of the single hydraulic support and fixes it together.

[0014] In the above scheme, since the template triangular support part also temporarily supports the top plate and is under heavy load, when moving the template, first use a jack to support the bottom of the triangular support, then turn the lifting screw to raise the support plate and lower the universal wheel.

[0015] In the above scheme, watertight tie rods are placed on the formwork panels to secure the two sides of the formwork. They provide the majority of lateral support during filling, enhancing the stability of the filling and formwork. When arranged on the panels, the watertight tie rods are spaced between the triangular supports and secured with cast steel nuts and cast steel washers, with a spacing of generally 700 to 800 mm. The diameter of the tie rods can be 12 mm, 14 mm, 16 mm, 18 mm, etc., depending on the height and width of the filling. The length of the tie rods should be determined according to the relevant standards based on the width of the filling and other conditions.

[0016] In the above scheme, when moving the formwork, first use a jack to support the bottom of the triangular bracket, then turn the lifting screw to raise the support plate and place the universal wheel perpendicular to the filling wall, and move the bracket away from the filling body to separate it from the tension screw structure; the formwork can then continue the next cycle of filling work, and when the direction needs to be rotated, the universal wheel can be turned to change the moving direction.

[0017] A sponge strip is installed between the steel formwork and the wooden strip. The sponge strip is the same width as the wooden strip and the horizontal frame of the steel formwork, has a certain thickness, and is much longer than the width and thickness of the sponge to achieve the purpose of water stopping. The thickness of the sponge strip should be determined according to the actual water stopping situation.

[0018] The present invention provides a method for using the above-mentioned temporary support wall type movable formwork that is liftable, detachable, and slidable for pouring underground filling, comprising the following steps:

[0019] (1) Based on the geological conditions and rock parameters of the filling area and the measured data of the filling working face, FLAC numerical simulation software is used to establish a model with a range of 3-5 times the filling area, and the geological conditions of the goaf area are simulated according to the actual conditions;

[0020] (2) The filling spacing takes different values, and the monitoring objects are the direct roof subsidence between the model filling spacings, the vertical stress between the filling spacings, the vertical stress of the bottom plate between the filling spacings, and the deformation of the bottom plate between the filling spacings, which correspond to the deformation of the direct roof, the ultimate bearing capacity of the direct roof, the ultimate bearing capacity of the bottom plate, and the deformation of the bottom plate, respectively. They are used to determine the reasonable filling spacing using FLAC numerical simulation software under the condition that the top and bottom plates remain stable and the strength of the top and bottom plates is fully utilized;

[0021] FLAC numerical simulation software was used to simulate the deformation of the immediate roof under different filling height conditions. On the one hand, the immediate roof can fully exert its bearing capacity, and on the other hand, the filling body will have a certain degree of compression and creep after solidification. Therefore, the filling height of the strip filling body should be determined under the condition that the compression and creep of the filling body after solidification are less than the maximum deformation of the immediate roof under stable load.

[0022] (3) The triangular support is welded on the surface and then transported to the filling area through the tunnel;

[0023] Before filling, the materials required for the formwork are transported from the tunnel to the filling area. The formwork is then assembled under the protection of hydraulic support pillars. The height of the composite steel formwork and the height of the PVC-coated cloth are determined according to the conditions and requirements of use. The composite steel formwork is connected and fixed with bolts and nuts. The upper part of the composite steel formwork is composed of a sponge strip, one end of the PVC-coated cloth, and a wooden strip from bottom to top. The uppermost horizontal frame of the composite steel formwork, the sponge strip, one end of the PVC-coated cloth, and the wooden strip are connected and fixed with bolts and nuts.

[0024] Then combine the triangular support and the combined steel formwork. The double-number ten channel steel of the main back rib of the formwork is connected with a core belt between each two adjacent formworks and reinforced with a core belt pin. The formwork part and the triangular support are fixed with channel steel back rib fasteners at the intersection of each transverse back rib and the support.

[0025] The formwork is spliced under the protection of the filling hydraulic support and then pushed to the filling position. At this time, the triangular support part of the formwork can play a temporary support role.

[0026] (4) During filling, the tail end of the filling pipe can be hung on the top plate of the area to be filled, and the hanging position on the top plate can be adjusted as needed; in actual use, the tail end of the filling pipe is hung on the top plate of the area to be filled in advance, and then the single hydraulic support on the upper part of the triangular support carries the PVC coating cloth to rise; the PVC coating cloth set on the upper part of the template is deformable and adheres to the outer wall of the pipe in the area of the tail end of the filling pipe, while in other areas the PVC coating cloth can be carried by the hydraulic support to adhere to the top plate.

[0027] (5) After the filling work is completed, in order to exert the strength of the filling body, a combined load-bearing structure consisting of a top plate-temporary support device-floor collaborative load-bearing structure can be formed by the bottom lifting and supporting device of the triangular bracket, the double No. 14 channel steel and the top temporary support device to support the top plate; when the strength of the filling body is stable and the formwork can be removed according to relevant standards, the formwork can be moved, that is, after first removing the cast steel nut of the tension screw structure, use a jack to support the bottom of the triangular bracket, then turn the lifting screw to raise the support plate and make the universal wheel perpendicular to the filling wall, move the bracket away from the filling body to separate it from the tension screw structure; the formwork can continue the next cycle of filling work, and when the direction of rotation is required, the universal wheel can be turned to change the moving direction.

[0028] Beneficial effects of the present invention:

[0029] (1) The template material components are small in size and easy to transport; the required template area and shape can be freely combined by steel template and flexible template material - PVC coated cloth, which is flexible and convenient, with low total cost, high reuse efficiency and small workload.

[0030] (2) The template area and shape required for filling can be freely combined by the steel template and the flexible template material - PVC coated cloth. The flexible template material is used to adjust the height of the flexible template material at any time based on the combined steel template as the filling height changes, so as to adapt to the changes in the underground filling height of the coal mine. It is flexible and convenient, with low total cost, high reuse efficiency and small workload;

[0031] (3) During filling, there is no need to use filling hydraulic props at the filling site. The top plate is supported by a combined load-bearing structure consisting of a lifting and supporting device at the bottom of the triangular bracket, a double No. 14 channel steel, and a temporary support device at the top, which is composed of a top plate-temporary support device-floor collaborative load-bearing structure. This is simple and convenient.

[0032] (4) During filling, the adjustable lifting device, i.e., the lifting screw equipped with a threaded sleeve, can, on the one hand, allow the template to freely change in height within a certain range; on the other hand, it can make the template have the same inclination angle as the base plate, so that the bottom of the template fits tightly with the base plate. If necessary, a sponge strip can be placed between the bottom of the template and the base plate to prevent leakage;

[0033] (5) Based on the geological conditions and rock parameters of the filling area and the measured data of the filling working face, the appropriate filling spacing and filling height are obtained using FLAC numerical simulation software; on the one hand, the filling body can give full play to the support strength, and the direct top, filling body and bottom plate can coordinate the bearing; on the other hand, the filling material can be used more rationally to achieve the purpose of saving filling material;

[0034] (6) When using the template, the bottom plate supporting plate is relatively lower than the universal wheel by adjusting the lifting screw; when moving the template, the bottom plate supporting plate is relatively higher than the universal wheel by adjusting the lifting screw. The sliding universal wheel can move the template to the next side to carry out the next cycle of work. It is free and flexible, saving time and effort, and reducing total costs.

[0035] (7) Based on the geological conditions and rock parameters of the filling area and the measured data of the filling working face, the appropriate filling spacing and filling height are obtained using FLAC numerical simulation software; on the one hand, the filling body can fully exert its support strength, and the direct top, filling body and bottom plate can cooperate to bear the load; on the other hand, the filling material can be more reasonably utilized to achieve the purpose of saving filling materials. (8) During filling, the adjustable lifting device, that is, the lifting screw equipped with a threaded sleeve, can, on the one hand, allow the template to change freely within a certain height range; on the other hand, it can make the template have the same inclination angle as the bottom plate, so that the bottom of the template fits tightly with the bottom plate. If necessary, a sponge strip can be placed between the bottom of the template and the bottom plate to prevent leakage. Similarly, the top PVC coated cloth and the top plate fit tightly together to tightly seal the filling area so that the filling slurry does not leak out of the filling area. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 is a schematic diagram of the structure of a temporary retaining wall type movable formwork (side view).

[0037] Figure 2 is a schematic diagram of the splicing structure of the combined steel formwork of the formwork part.

[0038] Figure 3 is a schematic diagram of the longitudinal frame of the combined steel formwork.

[0039] Figure 4 is a schematic diagram of the horizontal frame of the combined steel formwork.

[0040] Figure 5 is a schematic diagram of the horizontal splicing of the template.

[0041] Figure 6 is a schematic diagram of the longitudinal splicing of the template.

[0042] Figure 7 is a schematic diagram of the structure of the template when it is working.

[0043] Figure 8 is a schematic diagram of the support structure of the PVC coated cloth (nylon) and temporary support above the formwork when it is working.

[0044] Figure 9 is a schematic diagram of the structure of the channel steel back rib fastener.

[0045] Figure 10 Schematic diagram of the connection structure of channel steel back rib fasteners.

[0046] FIG11 is a schematic diagram of a single hydraulic support at the top of the formwork triangular support.

[0047] Figure 12 is a schematic diagram of the lifting and sliding device structure at the bottom of the template triangle bracket.

[0048] Figure 13 is a schematic diagram of the lifting and supporting device structure at the bottom of the template triangular support.

[0049] Figure 14 is a schematic diagram of the water-stop tension screw structure of the template.

[0050] In the figure: 1. Panel; 2. Horizontal frame; 3. Longitudinal rib; 4. Horizontal rib; 5. Longitudinal frame; 6. Back rib; 7. Nut; 8. Sponge strip; 9. M16 bolt; 10. Wooden strip; 11. PVC coated cloth; 12. Channel steel back rib fastener; 13. Top support plate; 14. Single hydraulic support; 15. Double No. 14 channel steel; 16. Connecting steel pipe; 17. Steel pipe fastener; 18. Double No. 10 channel steel; 19. Threaded sleeve; 20. Universal wheel; 21. Lifting screw; 22. Bottom support plate; 23. Water-stop tension screw; 24. Cast steel nut; 25. Cast steel gasket. DETAILED DESCRIPTION

[0051] The present invention is further illustrated by the following examples, but is not limited to the following examples. Example

[0052] like Figures 1 to 14 As shown, a temporary support wall-type mobile formwork for pouring underground filling that is liftable, removable, and slidable consists of a formwork portion and a triangular support portion. The main body of the formwork portion is a composite steel formwork, which is fixed together with bolts. A flexible formwork material, PVC-coated cloth 11, is placed above the composite formwork. The bottom edge of the PVC-coated cloth 11 is placed on the horizontal frame 2 above the composite steel formwork. Wooden strips 10 of the same width as the horizontal frame 2 are placed on top of the PVC-coated cloth 11. The horizontal frame 2 above the composite steel formwork, the PVC-coated cloth 11, and the wooden strips 10 are fixed together with bolts, thus forming the entire formwork portion. The formwork portion and the triangular support portion are connected and fixed by double-number ten channel steel 18, and the triangular support portion is fixed to the channel steel back rib fastener 12. The triangular support section is composed of several triangular supports, depending on the specific situation. These supports are connected by connecting steel pipes 16 and secured to the support by steel pipe fasteners 17. A single triangular support is composed of a pair of No. 10 channel steels 18 and a pair of No. 14 channel steels 15, forming a triangular truss. The bottom of the triangular truss is equipped with a lifting and supporting device and a sliding device, and the top is equipped with a temporary support device. Using this formwork not only enhances the strength of the filling and reduces its compression, but also provides temporary support for the roof, forming a combined load-bearing structure where the roof, temporary support device, and floor work together.

[0053] Secondly, the bottom lifting and supporting device of the triangular support is constructed. A threaded sleeve with a base is welded under the double No. 10 channel steel at the bottom of the triangular support, and a lifting screw 21 is welded to the bottom support plate 22, forming the lifting and supporting device. On the one hand, it forms a combined load-bearing structure of top plate, temporary support device, and floor with coordinated load-bearing. On the other hand, adjusting the lifting screw controls the formwork height to accommodate the tilted bottom plate. The bottom sliding device of the triangular support is constructed. A threaded sleeve with a base is welded under the double No. 10 channel steel at the bottom of the triangular support, and a lifting screw is welded to the universal wheel, forming the sliding device. When the formwork is in use, the lifting screw is adjusted to keep the bottom support plate relatively lower than the universal wheel. When moving the formwork, the lifting screw is adjusted to keep the bottom support plate relatively higher than the universal wheel. Sliding the universal wheel allows the formwork to move to the next side for the next cycle. The temporary support device at the top of the triangular support is constructed. A single hydraulic support with a base is welded to the double No. 14 channel steel at the top of the triangular support, and a top support plate 13 forms the temporary support device at the top.

[0054] During the strip filling construction, wall-type movable formwork can be used and arranged symmetrically on both sides to form the filling space of the filling strip; water-stopping tension screws 23 are arranged at the panel 1 of the formwork to fix the formwork on both sides and provide most of the lateral support force during filling, thereby enhancing the stability of the filling body and the formwork.

[0055] Figure 7 is a schematic diagram of the structure of the template when it is working. Figure 1 In the middle, the other end of the PVC coated cloth is folded but not raised; Figure 7 During the filling construction, the other end of the PVC coated cloth is fixed on the hydraulic support and rises with the hydraulic support until it is close to the top plate.

[0056] Figure 10 The figure is a schematic diagram of the connection structure of the channel steel back rib fastener. Figure 10 As shown, one side of the back rib fastener fixes the legs of the back rib to the legs of the No. 14 channel steel; the other side fixes the back rib fastener to the No. 14 channel steel through bolts to form a stable state.

[0057] Furthermore, in the above scheme, the composite steel formwork is 800mm long, 600mm high, and 5mm thick, made of Q235 steel plate. It consists of a faceplate 1, a transverse frame 2, and a longitudinal frame 5. The faceplate, which contacts the filling, is evenly distributed with transverse ribs 4 and longitudinal ribs 3. The transverse ribs 4 are made of Q235 steel plate, the longitudinal ribs 3 are made of No. 8 channel steel, and the back ribs 6 are made of double No. 10 channel steel. The transverse and longitudinal ribs are welded to the back of the faceplate (i.e., the side opposite the filling), and the back ribs are welded to the longitudinal ribs. Bolt holes are evenly distributed on the transverse and longitudinal frames.

[0058] In the above scheme, two adjacent composite steel formworks are fixed with M16 bolts and corresponding nuts and washers. The diameter of the M16 bolt is 16mm, the length is 60mm, the thickness of the nut is 15.9mm, the average thickness is 3mm, and the gasket is 4.1mm. The horizontal frame, PVC coated cloth and wooden strips above the composite steel formwork are also fixed with M16 bolts.

[0059] In the above scheme, the triangular support is welded from double No. 14 channel steel 15 and double No. 10 channel steel 18. The double No. 14 channel steel is used on the main facade, and is paired with the double No. 10 channel steel to form a triangular stable structure. The length and width of the triangular frame of the triangular support are determined according to the specific conditions of the filling work surface and the size of the formwork; the double No. 14 channel steel should extend upward 200mm to 300mm relative to the triangular frame.

[0060] In the above scheme, the back ribs and triangular supports are connected as follows: Channel back rib fasteners are used at the intersection of each cross rib and double 14 channel on one side of the double 10 channel steel. At the same time, the formwork back ribs of the double 10 channel steel are connected with core straps between each two adjacent formwork panels and reinforced with core strap pins, ensuring a tighter and more secure connection between the formwork and triangular supports. When fasteners are inconvenient, butt bolts can be used for connection.

[0061] As shown in Figure 9, the structure diagram of the back fastener and Figure 10 As shown in the schematic diagram of the back rib fastener connection structure, one side of the back rib fastener fixes the legs of the main back rib of the formwork (i.e., double No. 10 channel steel) and the legs of No. 14 channel steel together; on the other side, the back rib fastener is fixed to the No. 14 channel steel through bolts to form a stable state.

[0062] In the above scheme, the filling port is set at the top of the formwork, determined according to the height of the filling material to be filled, etc.; the filling material can generally be inserted from close to the top plate, or the filling port can be set at a fixed position on the formwork. If the filling port is not set specifically, the tail end of the filling pipe can be hung on the top plate of the area to be filled, and the hanging position on the top plate can be adjusted as needed; in actual use, the tail end of the filling pipe is pre-suspended on the top plate of the area to be filled, and then the single hydraulic support on the upper part of the triangular support is raised with the PVC coating cloth; the PVC coating cloth set on the upper part of the formwork is deformable, and in the area of the tail end of the filling pipe, it is closely attached to the outer wall of the pipe, while in other areas, the PVC coating cloth can be carried by the hydraulic support to be close to the top plate.

[0063] In the above scheme, a lifting and supporting device is set at the bottom of the triangular bracket, which consists of a threaded sleeve 19, a lifting screw 21 and a bottom plate support plate 22; the threaded sleeve and the lifting screw are made of Q45 steel, and the bottom plate support plate is made of Q235 steel. Figure 13 shown.

[0064] A sliding device is set at the bottom of the triangular support, which consists of a threaded sleeve 19, a lifting screw 21 and a universal wheel 20. The threaded sleeve and the lifting screw are made of Q45 steel, and the universal wheel is made of 45# steel, with a wheel diameter of 50mm and a wheel width of 32mm, and can carry a load of 160kg. A single hydraulic support and a support plate are set on the top of the triangular support to temporarily support the top plate; Figure 8 and Figure 11 As shown, a supporting plate is placed on the single hydraulic support, and a groove is provided at the bottom of the supporting plate to adapt to the upper part of the single hydraulic support and fix them together.

[0065] In the above scheme, since the template triangular support part also temporarily supports the top plate and is under heavy load, when moving the template, first use a jack to support the bottom of the triangular support, then turn the lifting screw to raise the support plate and lower the universal wheel.

[0066] In the above scheme, water-stopping tie screws 23 are arranged between the two panels to fix the formwork on both sides, and provide most of the lateral support force during filling, thereby enhancing the stability of the filling body and the formwork; when the water-stopping tie screws are arranged on the panels, they are spaced between the triangular brackets and fixed with cast steel nuts and cast steel washers, and the spacing is generally 700㎜ to 800㎜. The diameter of the tie screw can be 12mm, 14mm, 16mm, 18mm, etc., which is determined according to the height and width of the filling body; the length of the tie screw should be determined according to the corresponding standards based on the width of the filling body and other conditions. Figure 14 is a schematic diagram of the water-stopping tie screw structure of the formwork. Figure 14 As shown, when using wall-type movable formwork to be arranged symmetrically on both sides to form the filling space of the filling strip, water-stopping tension screws are arranged between the two panels and pass through the panels to fix the formwork on both sides and provide most of the lateral support force during filling, and cast steel nuts and cast steel washers are used to fix the water-stopping tension screws on the back ribs to enhance the stability of the filling body and the formwork.

[0067] In the above scheme, when moving the formwork, first use a jack to support the bottom of the triangular bracket, then turn the lifting screw to raise the support plate and place the universal wheel perpendicular to the filling wall, and move the bracket away from the filling body to separate it from the tension screw structure; the formwork can then continue the next cycle of filling work. When the direction needs to be rotated, the lifting screw can be turned to change the universal wheel to change the moving direction.

[0068] A sponge strip is installed between the steel formwork and the wooden strip. The sponge strip is the same width as the wooden strip and the horizontal frame of the steel formwork, has a certain thickness, and is much longer than the width and thickness of the sponge to achieve the purpose of water stopping. The thickness of the sponge strip should be determined according to the actual water stopping situation.

[0069] The present invention provides a method for using the above-mentioned temporary support wall type movable formwork that is liftable, detachable, and slidable for pouring underground filling, comprising the following steps:

[0070] (1) Based on the geological conditions and rock parameters of the filling area and the measured data of the filling working face, FLAC numerical simulation software is used to establish a model with a range of 3-5 times the filling area, and the geological conditions of the goaf area are simulated according to the actual conditions;

[0071] (2) The filling spacing takes different values, and the monitoring objects are the direct roof subsidence between the model filling spacings, the vertical stress between the filling spacings, the vertical stress of the bottom plate between the filling spacings, and the deformation of the bottom plate between the filling spacings, which correspond to the deformation of the direct roof, the ultimate bearing capacity of the direct roof, the ultimate bearing capacity of the bottom plate, and the deformation of the bottom plate, respectively. They are used to determine the reasonable filling spacing using FLAC numerical simulation software under the condition that the top and bottom plates remain stable and the strength of the top and bottom plates is fully utilized;

[0072] FLAC numerical simulation software was used to simulate the deformation of the immediate roof under different filling height conditions. On the one hand, the immediate roof can fully exert its bearing capacity, and on the other hand, the filling body will have a certain degree of compression and creep after solidification. Therefore, the filling height of the strip filling body should be determined under the condition that the compression and creep of the filling body after solidification are less than the maximum deformation of the immediate roof under stable load.

[0073] (3) Before filling, the materials required for the formwork are transported from the tunnel to the filling area, and the formwork is spliced under the protection of the filling hydraulic support. The height of the combined steel formwork and the height of the PVC coating cloth are determined according to the use conditions and requirements; the combined steel formwork is fixed by bolts and nuts. The upper side of the combined steel formwork is composed of sponge strips, one end of the PVC coating cloth, and wooden strips from bottom to top, such as Figure 6 As shown, the uppermost horizontal frame of the combined steel formwork, the sponge strip, one end of the PVC coated cloth and the wooden strip are connected and fixed by bolts and nuts;

[0074] Tripod part according to Figure 1 and Figure 7 The structure shown is welded. If the filling area conditions do not allow, the triangular support part can be welded on the surface and then transported to the filling area through the roadway;

[0075] Then combine the triangular support and the combined steel formwork. The double-number 10 channel steel of the main back rib of the formwork is connected with a core belt between each two adjacent formworks and reinforced with a core belt pin. The formwork part and the triangular support are fixed with channel steel back rib fasteners at the intersection of each transverse back rib and the support.

[0076] The formwork is spliced under the protection of the filling hydraulic support and then pushed to the filling position. At this time, the triangular support part of the formwork can play a temporary support role.

[0077] (4) During filling, the tail end of the filling pipe can be hung on the top plate of the area to be filled, and the hanging position on the top plate can be adjusted as needed; in actual use, the tail end of the filling pipe is hung on the top plate of the area to be filled in advance, and then the single hydraulic support on the upper part of the triangular support carries the PVC coating cloth to rise; the PVC coating cloth set on the upper part of the template is deformable and adheres to the outer wall of the pipe in the area of the tail end of the filling pipe, while in other areas the PVC coating cloth can be carried by the hydraulic support to adhere to the top plate.

[0078] (5) After the filling work is completed, in order to exert the strength of the filling body, a combined load-bearing structure consisting of a top plate-temporary support device-floor collaborative load-bearing structure can be formed by the bottom lifting and supporting device of the triangular bracket, the double No. 14 channel steel and the top temporary support device to support the top plate; when the strength of the filling body is stable and the formwork can be removed according to relevant standards, the formwork can be moved, that is, after first removing the cast steel nut of the tension screw structure, use a jack to support the bottom of the triangular bracket, then turn the lifting screw to raise the support plate and make the universal wheel perpendicular to the filling wall, move the bracket away from the filling body to separate it from the tension screw structure; the formwork can continue the next cycle of filling work, and when the direction of rotation is required, the universal wheel can be turned to change the moving direction.

[0079] The specific implementation method of the above-mentioned device is as follows: The 14307 working face in a certain mine has a mountain cover thickness of 125 to 245 meters. It overlies the goafs of the 12312, 12313, 12308, and 12309 working faces, and the rear half of the working face is underlain by the goafs of the 18305 and 18306 working faces. The working face is constructed along the 4# coal seam, which has a relatively stable thickness, averaging 3.05 meters, and an average dip of 3°. Geological data shows that the 4# coal seam is primarily lignite, interbedded with bright coal bands. The immediate roof of the 4# coal seam is siltstone, 2.35 meters thick, overlain by 0.15 meters of mudstone and 0.7 meters of fine-grained rock. The 4# coal seam is also closely spaced from the 2# and 3# coal seams.

[0080] Based on the geological conditions and rock formation parameters of the filling area and measured data from the filling working face, FLAC numerical simulation software was used to construct a model covering a range of 3-5 times the filling area. The geological conditions of the goaf, such as the length and inclination of the coal seam, were simulated according to actual conditions. The filling spacing was varied, and the monitoring targets were the immediate roof subsidence, vertical stress, vertical stress, and deformation of the floor between the filling spacings in the model. These correspond to the deformation of the immediate roof, the ultimate bearing capacity of the immediate roof, the ultimate bearing capacity of the floor, and the deformation of the floor, respectively. These parameters were used to determine the optimal filling spacing using FLAC numerical simulation software while maintaining the stability of the roof and floor and fully utilizing their strength. Based on the geological conditions and rock formation parameters, a 200m × 60m × 50m (length × thickness × height) model was constructed using FLAC3D numerical simulation software. Approximately 100m in the middle of the length of the 4# coal seam was excavated. The strip filling scheme was determined based on the critical filling spacing described above. The filling ratios for each strip filling scheme ranged from 45.5% to 49.5%, with negligible differences. Monitoring parameters included the immediate roof subsidence in the middle of the model thickness, the vertical stress at the top and bottom of the immediate roof, the stress at the waist of the filling strip (coal pillar), and the extent of the plastic zone. These parameters reflect the deformation of the immediate roof, the bearing capacity of the immediate roof on the overlying strata, the self-bearing capacity of the immediate roof, the bearing capacity of the filling strip, and the extent of structural failure. This analysis analyzed the stability of the "filling strip-immediate roof" composite bearing structure and determined the optimal filling spacing. Furthermore, based on a 2m filling strip spacing, the effects of varying filling strip widths and varying amounts of under-connected roof on the stability of the "filling strip-immediate roof" composite bearing structure were studied by varying the filling strip strength and height. The optimal filling strip width and maximum under-connected roof amount were determined.

[0081] FLAC 3D (Fast Lagrangian Analysis of Continua) numerical simulation software was used to simulate the deformation of the immediate roof at different filling heights. While this approach allows the immediate roof to fully exert its bearing capacity, it also results in a certain degree of compression and creep after solidification. Therefore, the strip filling height was determined to ensure that the compression and creep of the filling after solidification were less than the maximum deformation of the immediate roof under stable load-bearing conditions.

[0082] Backfill mining has a significant effect on controlling direct roof subsidence. As the backfill spacing decreases, the backfill strip's control effect on direct roof subsidence gradually increases, the wave-like subsidence becomes smoother, the deformation of the direct roof gradually decreases, and the underground space gradually increases. As the backfill spacing decreases, the vertical stress at the top of the direct roof becomes more uniform, significantly improving the bearing capacity of the direct roof above the void roof area. When the backfill spacing is less than 2m, it approaches the effect of full backfill, forming a stable direct roof bearing structure. As the backfill spacing decreases, the stress concentration at the bottom of the direct roof decreases, with the maximum value shifting from the strip edge to the strip center. The area above the void roof area where the direct roof is less than zero gradually decreases and disappears, facilitating the self-bearing capacity of the direct roof and achieving stability. As the backfill spacing decreases, the stress concentration at the waist of the backfill strip decreases, with the maximum stress shifting from the strip edge to the strip center, gradually approaching the design uniaxial compressive strength of the backfill strip, contributing to the stable bearing capacity of the backfill strip. As the filling spacing decreases, the scope of tensile failure of the direct roof and shear failure of the edge of the filling strip gradually decreases and disappears, which is beneficial to the stability of the "filling strip-direct roof" composite bearing structure. As the filling spacing decreases, the scope of tensile failure of the direct roof and shear failure of the edge of the filling strip gradually decreases and disappears, which is beneficial to the stability of the "filling strip-direct roof" composite bearing structure. As the filling spacing decreases, the bearing capacity of the direct roof is enhanced, and the force on the filling strip is more uniform, which is beneficial to the stability of the "filling strip-direct roof" structure. Taking into account the development and utilization of underground space after structural filling and mining, the vertical stress at the top of the direct roof and the plastic failure range of the filling body and the direct roof are the main judgment criteria, and it is determined that the filling spacing can be 2~5m.

[0083] As the width of the filling strip decreases, the bearing capacity of the top of the immediate roof above the void roof area first increases and then decreases. The difference in vertical stress between the top of the filling strip and the top of the immediate roof above the void roof area gradually decreases. A width of 2m results in a more uniform stress distribution, which facilitates the bearing of the immediate roof above the void roof area on the overlying strata. As the width of the filling strip decreases, the self-bearing capacity of the bottom of the immediate roof first increases and then decreases. At a width of 2m, the vertical stress at the bottom of the immediate roof above the void roof area is maximum, indicating the optimal self-bearing effect. In summary, as the width of the filling strip decreases, the design strength of the filling strip increases, and the bearing capacity of the immediate roof first increases and then decreases, reaching its maximum at a spacing of 2m. The more uniform stress distribution of the filling strip promotes its stability. However, compared with the spacing of the filling strips, the width of the filling strip has little effect on the stability of the "filling strip-immediate roof" structure. Based on the magnitude of the vertical stress at the top of the immediate roof and the range of plastic failure of the filling and the immediate roof as the primary criteria, the ideal width of the filling strip is determined to be approximately 2m.

[0084] Before filling, the materials required for the formwork are transported from the tunnel into the filling area. The formwork is then spliced together under the protection of the filling hydraulic stanchions. The formwork system and the triangular support system are first formed separately. The two parts are then combined. The main back ribs of the formwork (the main back ribs of the formwork are double-number 10 channel steels) are connected with core strips between each two adjacent formworks and reinforced with core strip pins. The formwork system and the triangular support are fixed with channel steel back rib fasteners at the intersection of each horizontal back rib and the support. The formwork is spliced together under the protection of the filling hydraulic stanchions and then pushed to the filling position. At this point, the triangular support portion of the formwork can serve as temporary support. Water-stop tension screws are arranged on the formwork panels to fix the formwork on both sides and provide the majority of the lateral support force during filling, enhancing the stability of the filling body and formwork.

Claims

1. A temporary retaining wall type movable formwork for pouring underground filling, characterized by: It consists of a template part and a triangular support part; The main body of the formwork is a composite steel formwork, which includes a panel, a horizontal frame, and a vertical frame. The panel is respectively provided with horizontal ribs, vertical ribs, and back ribs. The various components of the composite steel formwork are fixed together by bolts. A flexible formwork material is set above the composite formwork, and the bottom edge of the flexible formwork material is placed on the horizontal frame above the composite steel formwork. Wooden strips of the same width as the horizontal frame are placed on it. The horizontal frame above the composite steel formwork, the flexible formwork material, and the wooden strips are fixed together by bolts to form the entire formwork. The flexible formwork material is PVC-coated cloth made of nylon. A sponge strip is set between the steel formwork and the wooden strip. The sponge strip is the same width as the wooden strip and the horizontal frame of the steel formwork. The thickness of the sponge strip is determined according to the actual water-stopping conditions. The triangular support part is composed of several triangular supports, which are connected by steel pipes and fixed to the triangular supports by steel pipe fasteners. A single triangular support is composed of double No. 10 channel steel and double No. 14 channel steel to form a triangular truss. The bottom of the triangular truss is equipped with a lifting and supporting device and a sliding device, and a temporary supporting device is installed on the top. The formwork and the triangular support are connected and fixed by double No. 10 channel steel, and the triangular support is fixed to the channel steel back rib fastener by the channel steel back rib fastener; one side of the back rib is welded to the longitudinal rib of the formwork, and the other side is connected to the double No. 14 channel steel of the triangular support by the back rib fastener; A single hydraulic support and a supporting plate are set on the top of the triangular support for temporary support of the top plate; the supporting plate is placed on the single hydraulic support, and a groove is provided at the bottom of the supporting plate to adapt to the upper part of the single hydraulic support.

2. The temporary retaining wall type movable formwork for pouring underground filling according to claim 1 is characterized in that: The specifications of the combined steel formwork are 800㎜×600㎜, the panel thickness is 10mm, the horizontal and vertical frames are 5mm thick, and the steel formwork is connected by bolts; the height and length of the steel formwork are determined by the working surface mining height, the length of the strip filling, and the conditions of the top and bottom plates of the working surface.

3. The temporary retaining wall type movable formwork for pouring underground filling according to claim 1 is characterized in that: The triangular bracket is welded by double No. 14 channel steel and double No. 10 channel steel. Double No. 14 channel steel is used on the main facade and is matched with double No. 10 channel steel to form a triangular stable structure. The length and width of the triangular frame of the triangular bracket are determined according to the specific conditions of the filling working surface and the size of the template. The double No. 14 channel steel should extend upward by 200mm to 300mm relative to the triangular frame. The specifications of the combined steel template are 800mm in length, 600mm in height and 5mm in thickness.

4. The temporary retaining wall type movable formwork for pouring underground filling according to claim 1 is characterized in that: A lifting and supporting device is provided at the bottom of the triangular bracket, which consists of a threaded sleeve, a lifting screw and a bottom plate support plate; a sliding device is provided at the bottom of the triangular bracket, which consists of a threaded sleeve, a lifting screw and a universal wheel.

5. The temporary retaining wall type movable formwork for pouring underground filling according to claim 4 is characterized in that: Water-stopping tension screws are arranged between the two formworks to fix the formworks on both sides and provide most of the lateral support force during filling, thereby enhancing the stability of the filling body and the formworks. When the water-stopping tension screws are arranged on the panel, they are arranged at intervals between the triangular brackets and fixed with cast steel nuts and cast steel washers, with an interval distance of 700 mm to 800 mm.

6. The temporary retaining wall type movable formwork for pouring underground filling according to claim 1, characterized in that: The filling port is set at the top of the template and is determined according to the height of the filling body to be filled.

7. A method for using the temporary retaining wall type movable formwork for pouring underground filling according to claim 5, characterized in that The following steps are involved: (1) Based on the geological conditions and rock parameters of the filling area and the measured data of the filling working face, FLAC numerical simulation software is used to establish a model with a range of 3-5 times the filling area, and the geological conditions of the goaf area are simulated according to the actual conditions; (2) The filling spacing takes different values, and the monitoring objects are the direct roof subsidence between the model filling spacings, the vertical stress between the filling spacings, the bottom plate vertical stress between the filling spacings, and the bottom plate deformation between the filling spacings, which correspond to the deformation of the direct roof, the ultimate bearing capacity of the direct roof, the ultimate bearing capacity of the bottom plate, and the deformation of the bottom plate, respectively. They are used to determine the reasonable filling spacing using the FLAC numerical simulation software under the condition that the top and bottom plates remain stable and the strength of the top and bottom plates is fully exerted; the FLAC numerical simulation software is used to simulate the direct roof with a certain deformation under the condition of different values of the filling body height; on the one hand, the direct roof is fully exerted in terms of bearing capacity, and on the other hand, the filling body will have a certain degree of compression and creep after solidification; therefore, the filling height of the strip filling body should be determined under the condition that the compression and creep of the filling body after solidification are less than the maximum deformation of the direct roof for stable bearing; (3) The triangular support is welded on the surface and then transported to the filling area through the tunnel; Before filling, the materials required for the formwork are transported from the tunnel to the filling area. The formwork is then assembled under the protection of hydraulic support pillars. The height of the composite steel formwork and the height of the PVC-coated cloth are determined according to the conditions and requirements of use. The composite steel formwork is connected and fixed with bolts and nuts. The upper part of the composite steel formwork is composed of a sponge strip, one end of the PVC-coated cloth, and a wooden strip from bottom to top. The uppermost horizontal frame of the composite steel formwork, the sponge strip, one end of the PVC-coated cloth, and the wooden strip are connected and fixed with bolts and nuts. Then combine the triangular support and the combined steel formwork. The double-number ten channel steel of the main back rib of the formwork is connected with a core belt between each two adjacent formworks and reinforced with a core belt pin. The formwork part and the triangular support are fixed with channel steel back rib fasteners at the intersection of each transverse back rib and the support. After the template is spliced together under the protection of the filling hydraulic support, it is moved to the filling position. At this time, the template triangular support part can play the role of temporary support; (4) When filling, hang the tail end of the filling pipe on the top plate of the area to be filled, and adjust the hanging position on the top plate as needed; in actual use, the tail end of the filling pipe is hung on the top plate of the area to be filled in advance, and then the single hydraulic support on the upper part of the triangular support carries the PVC coating cloth and rises; the PVC coating cloth set on the upper part of the template is deformable, and in the area of the tail end of the filling pipe, it is close to the outer wall of the pipe, and in other areas, the PVC coating cloth can be carried by the hydraulic support to close to the top plate; (5) After the filling work is completed, since the filling body has not reached the strength of 28 days, the top plate is supported by a combined load-bearing structure consisting of a lifting and supporting device at the bottom of the triangular bracket, a double No. 14 channel steel, and a temporary support device at the top, which is composed of a top plate-temporary support device-floor collaborative load-bearing device; when the strength of the filling body is stable and the formwork is removed according to relevant standards, the formwork can be moved, that is, after removing the cast steel nut of the tension screw structure, a jack is used to support the bottom of the triangular bracket, and then the lifting screw is turned to raise the support plate and the universal wheel is perpendicular to the filling wall, and the bracket is moved away from the filling body to separate it from the tension screw structure; the formwork can continue the next cycle of filling work, and when the direction of rotation is required, the direction of movement is changed by turning the universal wheel.

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