A formwork structure for a special-shaped corner at a bottom of a shear wall and a construction method thereof

Abstract

The application discloses a formwork structure for a special-shaped corner of a bottom of a shear wall and a construction method thereof, and relates to the technical field of building construction; the formwork structure comprises a reentrant corner formwork assembly, the reentrant corner formwork assembly comprises a first panel, a second panel and a reentrant corner connecting strip, one side edge of the first panel is fixedly connected with one side of the reentrant corner connecting strip through a countersunk screw, and one side edge of the second panel is fixedly connected with the other side of the reentrant corner connecting strip through a countersunk screw. The reentrant corner connecting strip and a reentrant corner connecting component are used to change the special-shaped corner which needs to be cut and assembled manually on site into a prefabricated one in a factory and assembled on site; strip-shaped adjusting holes formed in the reentrant corner connecting strip allow a construction worker to use a bevel protractor to finely adjust the included angle of the first panel and the second panel on site, so that the forming angle precision of the special-shaped corner of the shear wall is ensured, and material waste and dust pollution caused by on-site cutting are avoided.

Description

Technical Field

[0001] This invention relates to the field of building construction technology, and in particular to a formwork structure for irregular corners at the bottom of shear walls and its construction method. Background Technology

[0002] In the construction of modern high-rise and super high-rise buildings, due to the diversification of building facades and the complexity of building functional layouts, the structural plan layout of shear walls is no longer limited to traditional straight lines or standard 90-degree right angles. Instead, a large number of irregular corner structures, such as 135-degree obtuse angles and 75-degree acute angles, have emerged. Currently, the industry commonly uses traditional on-site assembly and disassembly of wooden formwork for the formwork construction of these irregular corners. However, this process has the following problems in actual operation: Traditional methods typically rely on carpenters to manually cut wooden formwork on-site according to layout lines. Due to the low precision of on-site cutting and the lack of specialized connecting components for irregular angles, the splicing gaps between two panels at corners are often too large or the overlaps are uneven. The lateral pressure during concrete pouring can easily cause the formwork to deform and shift, resulting in obvious misalignment, chipped edges, and other dimensional deviations in the concrete components after demolding.

[0003] Furthermore, the bottom of the shear wall is the interface with the concrete of the lower floor slab, and this area often has uneven surfaces or a layer of laitance. Traditional formwork methods only lay a layer of ordinary sponge strips at the bottom of the formwork, lacking rigid bearing capacity and lateral sealing structures. During concrete pouring and vibration, highly fluid cement slurry will overflow in large quantities from the gap between the bottom of the formwork and the floor slab under lateral pressure. Slurry loss not only leads to quality defects such as honeycomb, pitting, and voids at the base of the wall, but also seriously affects the structural strength and durability of the shear wall. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by proposing a formwork structure and its construction method for irregular corners at the bottom of shear walls.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A formwork structure for irregular corners at the bottom of shear walls, comprising: An inside corner template assembly includes a first panel, a second panel, and an inside corner connecting strip; one side edge of the first panel is fixedly connected to one side of the inside corner connecting strip by countersunk screws, and one side edge of the second panel is fixedly connected to the other side of the inside corner connecting strip by countersunk screws, so that a first included angle greater than 90 degrees and less than 180 degrees is formed between the plane where the first panel is located and the plane where the second panel is located. The external corner template assembly includes a third panel, a fourth panel, and an external corner connecting member. The external corner connecting member includes an L-shaped base plate and L-shaped flanges on both sides of the L-shaped base plate. The edge of the third panel is fixed to one side of the L-shaped base plate with self-tapping screws, and the edge of the fourth panel is fixed to the other side of the L-shaped base plate with self-tapping screws, so that a second included angle greater than 0 degrees and less than 90 degrees is formed between the plane where the third panel is located and the plane where the fourth panel is located. The bottom sealing assembly includes a rubber sealing strip and an L-shaped grouting plate. The rubber sealing strip has a rectangular cross-section and is attached to the bottom edges of the first panel, second panel, third panel, and fourth panel respectively using nail-free adhesive. The horizontal plate of the L-shaped grouting plate is attached to the bottom surface of the rubber sealing strip, and the vertical plate of the L-shaped grouting plate is attached to the side of the floor slab. The L-shaped grouting plate is fixed to the floor slab with expansion bolts. Several back rib assemblies, the back rib assembly including horizontal back ribs and vertical back ribs, the horizontal back ribs being fixed to the back of the first panel, the second panel, the third panel and the fourth panel respectively by U-shaped buckles, and the vertical back ribs being fixed to the outside of the horizontal back ribs by wire binding. A plurality of tie bolt assemblies, wherein the tie bolt assembly includes a PVC sleeve and tie rods passing through the PVC sleeve, the tie rods passing through a first panel, a second panel, a third panel or a fourth panel and corresponding transverse back ribs and vertical back ribs in sequence, and being locked by a U-shaped clamp and a nut.

[0006] Preferably, the first panel, the second panel, the third panel and the fourth panel are all made of 15mm thick coated black phenolic resin template; the internal corner connecting strip and the external corner connecting component are all made of 2mm thick galvanized steel plate.

[0007] Preferably, the L-shaped grouting plate is a rubber sheet with a width of 50mm and a thickness of 3mm. The vertical plate height of the L-shaped grouting plate is not less than 30mm, and a wedge-shaped wooden plug is provided on the outer side of the vertical plate of the L-shaped grouting plate. The large end of the wedge-shaped wooden plug is pressed against the vertical plate of the L-shaped grouting plate.

[0008] Preferably, the rubber sealing strip has a height of 20mm and a width of 15mm, is made of neoprene rubber, and has several serrated grooves at the bottom end, with a depth of 2mm.

[0009] Preferably, the transverse back rib is a double steel pipe structure, consisting of two steel pipes with a diameter of 48mm and a wall thickness of 3.5mm tied side by side with iron wire; the vertical back rib is a single square timber with a cross-sectional dimension of 50mm×100mm, and the spacing between the vertical back ribs is 200mm to 300mm.

[0010] Preferably, the cross-section of the internal corner connecting strip is L-shaped, and strip-shaped adjustment holes are provided on both sides. The countersunk screw passes through the strip-shaped adjustment holes to fix the first panel and the second panel, so that the included angle of the first panel and the second panel can be finely adjusted by ±3 degrees through the strip-shaped adjustment holes.

[0011] Preferably, the L-shaped flange of the external corner connecting member is provided with several positioning holes, and the edges of the third panel and the fourth panel are provided with through holes corresponding to the positioning holes. Self-tapping screws pass through the through holes and positioning holes to fix the panel to the external corner connecting member.

[0012] Preferably, in the tie bolt assembly, both ends of the PVC sleeve are fitted with tapered rubber plugs, with the small end of the tapered rubber plug facing the inside of the template and the large end facing the outside of the template, and the diameter of the large end of the tapered rubber plug being larger than the outer diameter of the PVC sleeve.

[0013] A construction method for irregular corners at the bottom of shear walls includes the following steps: S1: Measure and set out, and mark the wall edge lines of the shear wall and the control lines of irregular corners on the floor slab surface; S2: Base treatment. Use an angle grinder to grind away the laitance on the floor slab surface inside the wall edge and apply double-sided tape to the wall edge. S3: Install the bottom sealing assembly, press the vertical plate of the L-shaped grouting board tightly against the wall edge, use expansion bolts to fix the L-shaped grouting board to the floor slab, and drive wedge-shaped wooden plugs into the outside of the vertical plate of the L-shaped grouting board for secondary tightening; S4: Assemble the internal corner template assembly. According to the designed first included angle, adjust the position of the first panel and the second panel on the internal corner connecting strip. Use countersunk screws to fix the panels and the connecting strip through the strip adjustment holes to form an internal corner template unit. S5: Assemble the external corner template component. According to the designed second included angle, place the third and fourth panels on both sides of the L-shaped base plate of the external corner connecting component. Use self-tapping screws to fix the panels to the component through the positioning holes to form an external corner template unit. S6: Install the surface template, hoist the assembled internal corner template unit and external corner template unit to the installation position, so that the bottom end of the rubber sealing strip is pressed firmly on the horizontal plate of the L-shaped grouting plate, then install the remaining standard flat templates, and use iron nails to fix the edges of adjacent templates; S7: Install the back rib assembly. Lay horizontal and vertical back ribs sequentially on the back of the template. The horizontal back ribs are perpendicular to the back of the template. Use U-shaped buckles to lock the horizontal back ribs onto the template. S8: Install the tie rod assembly, drill holes in the template, insert the PVC sleeve with the tapered rubber plug into the hole, insert the tie rod, and then put the U-shaped clips on the tie rods on both sides of the template and tighten the nuts to apply preload. S9: Correction and reinforcement. Use a plumb line and straightedge to check the verticality of the template. Correct the verticality by adjusting the tightness of the nuts on the tie rods. Connect the steel wire rope to the ground anchor at the top of the template for diagonal fixation. S10: Pouring concrete, pouring shear wall concrete in layers, with each layer not exceeding 500mm in thickness, and the spacing between vibrators not exceeding 400mm. S11: Demolding and cleaning. After the concrete strength reaches 75% of the design strength, remove the tie rods, back rib assembly, surface formwork and bottom sealing assembly in sequence, and clean up the remaining cement slurry.

[0014] Preferably, in step S4, the step of adjusting the angle between the first panel and the second panel specifically includes: using an angle gauge to measure the angle between the first panel and the second panel; when the angle deviation is greater than 0.5 degrees, loosening the countersunk screw, sliding the panel along the strip adjustment hole until the angle gauge reading meets the design requirements, and then retightening the countersunk screw. In step S6, after installing the surface template, apply glass glue to the template joints. The glass glue is a neutral silicone weather-resistant adhesive, and the application width is 10mm to 15mm. In step S8, when applying the preload, a torque wrench is used to tighten the nut, and the torque wrench is set to a torque value of 40 N·m to 60 N·m. In step S11, when removing the bottom sealing assembly, first use a flathead screwdriver to insert into the gap between the L-shaped grouting plate and the floor slab, and gently pry it to separate the rubber sealing strip from the grouting plate. Then remove the expansion bolts to prevent the concrete at the irregular corner from chipping due to violent removal.

[0015] The beneficial effects of this invention are as follows: 1. This invention uses internal corner connecting strips and external corner connecting components to change the original need for on-site manual cutting and assembly of irregular corners to factory prefabrication and on-site assembly; the strip-shaped adjustment holes opened on the internal corner connecting strips allow construction personnel to use an angle ruler to fine-tune the angle between the first panel and the second panel on-site, which not only ensures the forming angle accuracy of the irregular corners of the shear wall, but also avoids material waste and dust pollution caused by on-site cutting.

[0016] 2. This invention employs a bottom sealing assembly consisting of a rubber sealing strip, an L-shaped grouting plate, and a wedge-shaped wooden plug. The rubber sealing strip provides the first layer of flexible sealing, filling the tiny gaps between the template and the grouting plate. The L-shaped grouting plate, as a rigid support structure, prevents the overflow of concrete grout. The secondary tightening of the wedge-shaped wooden plug further eliminates the installation gap between the grouting plate and the floor slab. This multi-layered sealing structure can withstand the high lateral pressure during concrete pouring, fundamentally solving the common quality problems of root rot and grout leakage at the base of shear walls.

[0017] 3. The external corner connecting component of the present invention adopts an L-shaped base plate and a flange design. The panel is fixed to the component by self-tapping screws instead of the traditional direct nailing. When dismantling the formwork, the construction personnel only need to unscrew the self-tapping screws to remove the panel smoothly from the concrete surface, avoiding the damage to the irregular corner concrete edges caused by using a pry bar to forcibly pry it, ensuring the molding quality of fair-faced concrete and reducing the later repair costs. Attached Figure Description

[0018] The accompanying drawings, which form part of this application, are used to provide a further understanding of the application and to make other features, objects, and advantages of the application more apparent. The illustrative embodiments and descriptions of this application are used to explain the application and do not constitute an undue limitation of the application. In the drawings: Figure 1 This is a flowchart illustrating a construction method for a formwork structure at the bottom irregular corner of a shear wall, as proposed in this invention. Detailed Implementation

[0019] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0020] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0021] In this application, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.

[0022] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0023] In addition, the term "multiple" should mean two or more.

[0024] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0025] Example 1: Formwork structure for irregular corners at the bottom of shear walls A formwork structure for irregular corners at the bottom of shear walls mainly consists of the following components: Internal corner formwork assembly: used for the internal corners of shear walls; two 2000mm×1000mm thick, 15mm thick coated black phenolic resin formwork panels are used as the first and second panels; a 2000mm long, L-shaped galvanized steel plate is used as the internal corner connecting strip, with each side of the connecting strip being 50mm wide and 2mm thick; on both sides of the connecting strip, an oblong hole is made every 200mm as a strip-shaped adjustment hole, with a length of 20mm and a width of 8mm; align the edge of the first panel with one side of the connecting strip, and use a 25mm long countersunk self-tapping screw to screw into the edge of the panel through the strip-shaped adjustment hole, ensuring that the screw head is 0.5mm below the panel surface; similarly, fix the second panel to the other side of the connecting strip; at this time, the first panel and the second panel form a first included angle A, which can be adjusted by sliding the screw in the strip-shaped adjustment hole, with an adjustment range of 90 degrees to 120 degrees.

[0026] External corner formwork assembly: used for the external corner of shear walls; take the third and fourth panels, which are made of the same material as the first panel; take the external corner connecting component, which consists of an L-shaped base plate and an L-shaped flange. The width of the L-shaped base plate is 60mm and the height of the L-shaped flange is 15mm. The two are welded perpendicularly; on the L-shaped base plate, a positioning hole with a diameter of 4mm is opened every 150mm; place the edge of the third panel on one side of the L-shaped base plate, so that the edge of the panel is 2mm away from the inside of the flange, and use a 16mm long self-tapping screw to pass through the panel and screw it into the positioning hole; the fourth panel is installed in the same way; a second included angle B is formed between the third and fourth panels. This included angle is determined according to the bending angle of the component, usually between 45 degrees and 89 degrees.

[0027] Bottom sealing assembly: Take a neoprene rubber sealing strip with a cross-section of 15mm × 20mm; apply neoprene rubber all-purpose adhesive to the adhesive surface of the sealing strip and attach it to the bottom of the first panel, second panel, third panel, and fourth panel respectively, with the adhesive position 5mm away from the bottom edge of the panel; take an L-shaped grouting board, which is made of 3mm thick rubber sheet, with a horizontal board width of 50mm and a vertical board height of 40mm; before installing the template, place the L-shaped grouting board on the floor slab, with the inner side of its vertical board 2mm away from the wall edge; use an electric drill to drill holes in the vertical board and drive expansion bolts into the floor slab to fix the grouting board; then, drive wedge-shaped wooden plugs into the gap between the outer side of the vertical board of the grouting board and the floor slab, and use a claw hammer to tap the wooden plugs to make them tighten against the grouting board.

[0028] Reinforcement components: On the back of the panel, horizontal back ribs are laid horizontally; the horizontal back ribs 9 are made of double steel pipes, consisting of two Φ48×3.5mm steel pipes arranged side by side; U-shaped clips are used to clip the horizontal back ribs onto the panel, with a clip spacing of 600mm; on the outside of the horizontal back ribs, vertical back ribs are laid vertically, using 50mm×100mm square timber, with a center distance of 250mm between the timbers; the vertical back ribs are tied and fixed to the horizontal back ribs with wire; finally, 20mm diameter bolt holes are drilled in the template, PVC sleeves are inserted, and M14 tie rods are inserted into the sleeves; on both sides of the template, U-shaped clips are fitted onto the tie rods, and the nuts are tightened using a torque wrench, with the torque set to 50N·m.

[0029] Example 2: Construction method for irregular corners at the bottom of shear walls Based on Example 1, this embodiment includes the following specific operations in its construction method: S1: Surveying and setting out; Construction workers use a total station to set out the wall edge lines of the shear wall on the concrete surface of the floor slab; for irregular corners, a theodolite is used to set out the control lines of the corners, and positioning steel bars are driven in at a distance of 500mm from the corner as markers; S2: Base treatment; Use an angle grinder with diamond grinding discs to grind the floor slab surface within 50mm of the wall edge to remove the surface laitance and loose stones until a solid concrete base is exposed; After cleaning the dust, stick a 10mm wide double-sided foam tape around the wall edge. S3: Install the bottom sealing assembly; place the L-shaped grouting board along the wall edge, drill holes in the floor slab with an impact drill to a depth of 40mm, and insert M6 expansion bolts; tighten the nuts with a wrench to make the horizontal plate of the grouting board fit tightly against the floor slab; then, drive a wedge-shaped wooden plug into the outside of the vertical plate of the grouting board every 300mm, with the small end of the wooden plug facing outward, and tap the large end with a hammer to make the wooden plug press tightly against the vertical plate; S4: Assemble the inside corner template assembly; On the hardened ground, place the first and second panels on the inside corner connecting strip; Use a universal angle gauge to measure the included angle between the two panels, and adjust the panel position according to the drawing requirements; When the bubble of the angle gauge is centered, use an electric drill and PH2 screwdriver bit to screw the countersunk screws into the panel to complete the overall assembly of the inside corner unit. S5: Assemble the external corner template assembly; place the third and fourth panels against the L-shaped base plate of the external corner connecting component, use a right-angle ruler to check the perpendicularity of the panel edge and the flange, and after confirming that there is no error, use a screwdriver to screw in the self-tapping screws to complete the assembly of the external corner unit. S6: Install the surface template; use a tower crane to hoist the assembled internal and external corner units to the installation position; slowly lower them so that the rubber sealing strip at the bottom of the panel presses onto the horizontal plate of the L-shaped grouting board; then, install the standard flat template and use nails to nail the edges of adjacent templates together; at the template joints, use a caulking gun to apply neutral silicone weather-resistant sealant and smooth the gaps. S7: Install the back rib assembly; on the back of the template, lay horizontal double steel pipes at 300mm intervals, use U-shaped clips to insert from the front of the panel, fasten the steel pipes and lock them; then, lay square timber back ribs vertically on the outside of the steel pipes, wrap the contact points between the square timber and the steel pipes with wire twice and tighten them. S8: Install the tie bolt assembly; mark the tie bolt hole positions on the template and drill the holes with an electric drill; put tapered rubber plugs on both ends of the PVC sleeve and insert the small end of the plug into the hole; insert the tie bolt, put the U-shaped clips on both sides, and tighten the nut with a torque wrench at a torque of 50 N·m; S9: Correction and reinforcement; Fix a plumb line to the top of the formwork, and the surveyor observes on the floor whether the plumb line is aligned with the control line; If there is a deviation, use a pry bar to gently pry the formwork and adjust the tightness of the tie nuts; Weld steel anchors to the top of the formwork 300mm from the corner, and pull 8mm diameter steel wire ropes to fix the formwork diagonally with turnbuckles; S10: Concrete pouring; the concrete mixer truck unloads C40 concrete into the hopper and uses a truck pump for pouring; during pouring, a 50mm thick layer of mortar of the same grade is first laid at the corner; then the concrete is poured in layers, with each layer controlled to be 400mm thick; the vibrator operator uses a 50mm diameter immersion vibrator and vibrates according to the principle of quick insertion and slow withdrawal. The vibrator is inserted 50mm into the lower layer of concrete, and the vibration time is controlled to be 20 to 30 seconds, until the concrete surface no longer sinks significantly and no air bubbles emerge. S11: Formwork Removal and Cleaning; 48 hours after pouring, formwork removal begins; first, use a wrench to loosen the tie nuts and remove the nuts and U-shaped clips; then remove the horizontal and vertical back ribs; next, use a flathead screwdriver to insert into the gap between the L-shaped grouting plate and the floor slab, and gently pry to separate the rubber sealing strip from the grouting plate; remove the expansion bolts and remove the grouting plate; finally, unscrew the self-tapping screws on the corner connecting components and remove the third and fourth panels from the concrete surface; clean the concrete residue on the formwork surface, apply release agent, and prepare for the next use.

[0030] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A formwork structure for irregular corners at the bottom of shear walls, characterized in that, include: An inside corner template assembly includes a first panel, a second panel, and an inside corner connecting strip; one side edge of the first panel is fixedly connected to one side of the inside corner connecting strip by countersunk screws, and one side edge of the second panel is fixedly connected to the other side of the inside corner connecting strip by countersunk screws, so that a first included angle greater than 90 degrees and less than 180 degrees is formed between the plane where the first panel is located and the plane where the second panel is located. The external corner template assembly includes a third panel, a fourth panel, and an external corner connecting member. The external corner connecting member includes an L-shaped base plate and L-shaped flanges on both sides of the L-shaped base plate. The edge of the third panel is fixed to one side of the L-shaped base plate with self-tapping screws, and the edge of the fourth panel is fixed to the other side of the L-shaped base plate with self-tapping screws, so that a second included angle greater than 0 degrees and less than 90 degrees is formed between the plane where the third panel is located and the plane where the fourth panel is located. The bottom sealing assembly includes a rubber sealing strip and an L-shaped grouting plate. The rubber sealing strip has a rectangular cross-section and is attached to the bottom edges of the first panel, second panel, third panel, and fourth panel respectively using nail-free adhesive. The horizontal plate of the L-shaped grouting plate is attached to the bottom surface of the rubber sealing strip, and the vertical plate of the L-shaped grouting plate is attached to the side of the floor slab. The L-shaped grouting plate is fixed to the floor slab with expansion bolts. The back rib assembly includes a horizontal back rib and a vertical back rib. The horizontal back rib is fixed to the back of the first panel, the second panel, the third panel and the fourth panel respectively by U-shaped buckles. The vertical back rib is fixed to the outside of the horizontal back rib by wire binding. A tie bolt assembly, comprising a PVC sleeve and a tie rod inserted inside the PVC sleeve, the tie rod passing sequentially through a first panel, a second panel, a third panel or a fourth panel and corresponding transverse and vertical back ribs, and being locked in place by a U-shaped clamp and a nut.

2. The formwork structure for irregular corners at the bottom of shear walls according to claim 1, characterized in that, The first panel, second panel, third panel and fourth panel are all made of coated black phenolic wood template; the inside corner connecting strip and outside corner connecting component are all made of galvanized steel sheet.

3. A formwork structure for irregular corners at the bottom of a shear wall according to claim 1, characterized in that, The L-shaped grouting plate is made of rubber. A wedge-shaped wooden plug is also provided on the outer side of the vertical plate of the L-shaped grouting plate. The large end of the wedge-shaped wooden plug is pressed against the vertical plate of the L-shaped grouting plate.

4. A formwork structure for irregular corners at the bottom of a shear wall according to claim 1, characterized in that, The rubber sealing strip is made of neoprene rubber, and the bottom end of the rubber sealing strip has several serrated grooves.

5. A formwork structure for irregular corners at the bottom of a shear wall according to claim 1, characterized in that, The transverse back rib is a double steel pipe structure, consisting of two steel pipes with a diameter of 48mm and a wall thickness of 3.5mm tied side by side with iron wire.

6. A formwork structure for irregular corners at the bottom of a shear wall according to claim 1, characterized in that, The cross-section of the internal corner connector is L-shaped, and strip-shaped adjustment holes are provided on both sides. The countersunk screw passes through the strip-shaped adjustment holes to fix the first panel and the second panel, so that the included angle between the first panel and the second panel can be adjusted through the strip-shaped adjustment holes.

7. A formwork structure for irregular corners at the bottom of a shear wall according to claim 1, characterized in that, The L-shaped flange of the external corner connecting member is provided with several positioning holes. The edges of the third panel and the fourth panel are provided with through holes corresponding to the positioning holes. Self-tapping screws pass through the through holes and positioning holes to fix the panel to the external corner connecting member.

8. A formwork structure for irregular corners at the bottom of a shear wall according to claim 1, characterized in that, In the tie bolt assembly, both ends of the PVC sleeve are fitted with tapered rubber plugs. The small end of the tapered rubber plug faces the inside of the template, and the large end faces the outside of the template. The diameter of the large end of the tapered rubber plug is larger than the outer diameter of the PVC sleeve.

9. A construction method for irregular corners at the bottom of shear walls, applied to the formwork structure described in any one of claims 1 to 8, characterized in that, Includes the following steps: S1: Measure and set out, and mark the wall edge lines of the shear wall and the control lines of irregular corners on the floor slab surface; S2: Base treatment. Use an angle grinder to grind away the laitance on the floor slab surface inside the wall edge and apply double-sided tape to the wall edge. S3: Install the bottom sealing assembly, press the vertical plate of the L-shaped grouting board tightly against the wall edge, use expansion bolts to fix the L-shaped grouting board to the floor slab, and drive wedge-shaped wooden plugs into the outside of the vertical plate of the L-shaped grouting board for secondary tightening; S4: Assemble the internal corner template assembly. According to the designed first included angle, adjust the position of the first panel and the second panel on the internal corner connecting strip. Use countersunk screws to fix the panels and the connecting strip through the strip adjustment holes to form an internal corner template unit. S5: Assemble the external corner template component. According to the designed second included angle, place the third and fourth panels on both sides of the L-shaped base plate of the external corner connecting component. Use self-tapping screws to fix the panels to the component through the positioning holes to form an external corner template unit. S6: Install the surface template, hoist the assembled internal corner template unit and external corner template unit to the installation position, so that the bottom end of the rubber sealing strip is pressed firmly on the horizontal plate of the L-shaped grouting plate, then install the remaining standard flat templates, and use iron nails to fix the edges of adjacent templates; S7: Install the back rib assembly. Lay horizontal and vertical back ribs sequentially on the back of the template. The horizontal back ribs are perpendicular to the back of the template. Use U-shaped buckles to lock the horizontal back ribs onto the template. S8: Install the tie rod assembly, drill holes in the template, insert the PVC sleeve with the tapered rubber plug into the hole, insert the tie rod, and then put the U-shaped clips on the tie rods on both sides of the template and tighten the nuts to apply preload. S9: Correction and reinforcement. Use a plumb line and straightedge to check the verticality of the template. Correct the verticality by adjusting the tightness of the nuts on the tie rods. Connect the steel wire rope to the ground anchor at the top of the template for diagonal fixation. S10: Pouring concrete, pouring shear wall concrete in layers; S11: Demolding and cleaning. After the concrete strength reaches 75% of the design strength, remove the tie rods, back rib assembly, surface formwork and bottom sealing assembly in sequence, and clean up the remaining cement slurry.

10. A construction method for an irregular corner at the bottom of a shear wall according to claim 9, characterized in that, In step S4, the step of adjusting the angle between the first panel and the second panel specifically includes: using an angle gauge to measure the angle between the first panel and the second panel; when the angle deviation is greater than the predetermined angle, loosening the countersunk screw, sliding the panel along the strip adjustment hole until the angle gauge reading meets the design requirements, and then retightening the countersunk screw. In step S6, after installing the surface template, apply glass glue to the template joints. The glass glue is a neutral silicone weather-resistant adhesive. In step S8, when applying preload, tighten the nut using a torque wrench; In step S11, when removing the bottom sealing assembly, first use a flathead screwdriver to insert into the gap between the L-shaped grouting plate and the floor slab, and gently pry it to separate the rubber sealing strip from the grouting plate. Then remove the expansion bolts to prevent the concrete at the irregular corner from chipping due to violent removal.

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