Building underground assembly type sleeve and formwork structure and construction method

Abstract

The invention relates to the field of construction, and discloses a building underground assembly type casing pipe and formwork structure and a construction method, the building underground assembly type casing pipe and formwork structure comprises a casing pipe assembly, a formwork assembly and a fastening assembly, the casing pipe assembly comprises a steel casing pipe, a bias ring and a water stop ring, the formwork assembly comprises a batten, a steel pipe and a bamboo plywood, and the fastening assembly comprises a mountain-shaped clamp, a nut and a split screw; the water stop ring is welded to the middle of the steel sleeve, the bias rings are arranged on the two sides of the steel sleeve respectively, the bamboo plywood is tightly attached to the bias rings, the sponge strip is clamped between the bamboo plywood and the bias rings, the batten and the steel pipe are sequentially laid on the outer side of the bamboo plywood, and the opposite-pull screw penetrates through the formwork assembly and is locked through the E-shaped clamp and the nut. The defect that a wall penetrating part of a traditional pipeline is blocked violently is overcome, a regular forming boundary is provided for concrete, it is ensured that vibration is compact, bubbles are discharged, pore cracks are avoided, and structural integrity and construction quality are guaranteed.

Description

Technical Field

[0001] This invention relates to the field of construction, and in particular to a prefabricated underground casing and formwork structure and construction method for buildings. Background Technology

[0002] In large public buildings, the gaps between the sleeves and formwork at the pipe penetration points in the basement exterior walls are weak points in waterproofing and structural protection. Current underground engineering projects have increasingly higher requirements for the reliability of waterproofing, structural stability, and construction efficiency in this area. The construction quality directly affects the building's service life and safety, making the optimization of related structures and construction methods a key focus for the industry.

[0003] Existing technologies still have the following drawbacks: First, traditional methods of sealing pipe penetrations in exterior walls often rely on rough sealing with materials such as cotton cloth and hemp fibers, lacking a regular and integrated support structure. This results in insufficient vibration during concrete pouring, causing air bubbles to accumulate and form pores and cracks, leading to a loose structure and potential water seepage. Second, the waterproofing layer is singular and lacks multiple water-blocking structures, resulting in short seepage paths, high leakage risk, difficulty in meeting long-term waterproofing requirements, and high maintenance costs in the later stages. Summary of the Invention

[0004] To overcome the above shortcomings, this invention provides a prefabricated casing and formwork structure and construction method for underground buildings, aiming to improve the problem of traditional protection lacking a regular integrated support structure.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a prefabricated casing and formwork structure for underground construction, comprising a casing assembly, a formwork assembly, and a fastening assembly. The casing assembly includes a steel casing, an offset ring, and a water-stop ring. The formwork assembly includes timber, a steel pipe, and bamboo plywood. The fastening assembly includes a U-shaped clamp, a nut, and a tie rod. The water-stop ring is welded to the middle of the steel casing. The two offset rings are respectively welded to both sides of the steel casing. The timber is laid close to the outside of the bamboo plywood. The steel pipe is installed on the outside of the timber. The tie rod passes through the formwork assembly laterally and is locked and fixed at both ends by the U-shaped clamp and the nut. The bamboo plywood is tightly fitted to the outside of the offset ring, and a sponge strip is sandwiched between the offset ring and the bamboo plywood.

[0006] Preferably, the water-stop ring has grooves on both end faces, and water-swellable rubber strips are embedded in the grooves.

[0007] Preferably, both the water-stop ring and the offset ring are welded and fixed perpendicularly to the steel sleeve.

[0008] Preferably, the timber is laid at even intervals along the length of the bamboo plywood, and the steel pipe is set along the length of the timber and closely fitted to the timber.

[0009] Preferably, the outer diameter of the offset ring is 45mm to 60mm and the thickness is 3 to 5mm; the thickness of the water-stop ring is not less than 5mm, and the outer diameter of the water-stop ring is greater than the outer diameter of the offset ring.

[0010] A construction method for prefabricated sleeve and formwork structures in underground buildings includes the following steps:

[0011] S1: Process steel sleeve, water-stop ring, and offset ring. Process grooves on both ends of the water-stop ring and weld the water-stop ring to the middle of the steel sleeve. Weld the offset ring to both sides of the steel sleeve. Then install water-swellable rubber strips in the grooves to make an assembled sleeve assembly.

[0012] S2: Weld and fix the sleeve assembly to the wall reinforcement to ensure that the center line of the steel sleeve is perpendicular to the wall surface;

[0013] S3: Lay wooden strips on the outside of bamboo plywood, and then install steel pipes on the outside of the wooden strips. Secure the template components with matching fastening components, and at the same time, make the bamboo plywood and the offset ring fit tightly together to further ensure the sealing and leak-proof effect.

[0014] S4: Pour concrete into the formwork and vibrate it thoroughly. After the concrete has solidified to the specified strength, remove the formwork and continue to cure the concrete.

[0015] Preferably, before welding the offset ring and the water-stop ring in S1, the welding position line is marked on the surface of the steel sleeve to ensure accurate welding position.

[0016] Preferably, the fastening components in S3 are U-shaped clips, nuts, and tie rods. The tie rods pass horizontally through the bamboo plywood, timber, and steel pipe. After the steel pipe is clamped at both ends by U-shaped clips, the nuts are used to lock the tension and form a bidirectional tension to prevent the formwork from deforming during pouring.

[0017] Preferably, in step S3, a sponge strip is sandwiched between the tightly fitting surfaces of the bamboo plywood and the eccentric ring. The sponge strip seals the overlap gap between the bamboo plywood and the eccentric ring, preventing grout leakage.

[0018] Preferably, after the S4 concrete is poured, once it has solidified to the specified strength, the formwork is removed and the concrete is cured to ensure structural stability and waterproofing.

[0019] The present invention has the following beneficial effects:

[0020] 1. In this invention, the tight bonding between the bamboo plywood and the eccentric ring, along with the sponge strip between them, forms a regular molding boundary, providing a stable support for concrete flow and vibration. This solves many drawbacks of the traditional brute-force sealing method used for pipe penetrations through walls. Traditional brute-force sealing lacks a regular support structure, preventing sufficient vibration during concrete pouring. This results in insufficient density at the sealed area, with air bubbles trapped inside forming pores and cracks, exacerbating structural looseness and leading to extremely poor waterproofing reliability. This structure provides a regular molding boundary for the surrounding concrete, allowing it to flow fully and be vibrated to compact during pouring, completely avoiding localized looseness and ensuring structural integrity.

[0021] 2. This invention constructs a multi-layered, synergistic waterproofing system using a lateral ring, a water-stop ring, and a water-swellable rubber strip embedded in a groove, extending the seepage path through structural design. The water-stop ring is horizontally positioned in the middle of the steel sleeve, with an outer diameter larger than that of the lateral ring, forming a stepped water-blocking structure. The two lateral rings form the first waterproof interface with the concrete. The water-swellable rubber strip in the groove expands actively upon contact with water, tightly filling the gap between the strip and the concrete, forming an active waterproof barrier. When water attempts to seep in, it must successively overcome the interface between the outer lateral ring and the concrete, the sealing layer of the outer water-swellable rubber strip, the lateral obstruction of the water-stop ring, the sealing layer of the inner water-swellable rubber strip, and the interface between the inner lateral ring and the concrete. This multi-layered defense significantly extends the seepage path, completely changing the traditional single-layer waterproofing logic and significantly improving the long-term effectiveness and reliability of waterproofing.

[0022] 3. This invention achieves precise and secure formwork fixing through a fastening assembly composed of a U-shaped clamp, a nut, and a tie rod, providing crucial assurance for the quality of concrete forming and sealing effect. Traditional formwork reinforcement methods often suffer from uneven stress and insecure fixing, leading to problems such as formwork bulging and displacement when lateral pressure is generated during concrete pouring. In this structure, the tie rod passes horizontally through the formwork assembly, and both ends are locked with the nuts via U-shaped clamps. The U-shaped clamps precisely engage the formwork, preventing slippage of the locking force. The tightening of the nuts creates a balanced and continuous bidirectional tension, precisely balancing the lateral pressure of the concrete and firmly locking the formwork in position, ensuring that the formwork remains flat and stable at all times. This reinforcement method effectively prevents formwork deformation and displacement during pouring, ensuring the flatness of the concrete appearance and the accuracy of structural dimensions after forming. It also maintains a tight fit between the eccentric ring and the formwork, preventing sealing failure due to formwork loosening. This further eliminates the risk of grout leakage during construction and works synergistically with the sealing structure of the sleeve to comprehensively guarantee project quality. Attached Figure Description

[0023] Figure 1 This is a first-view diagram of the present invention;

[0024] Figure 2 This is a first-view diagram of the present invention;

[0025] Figure 3 A schematic diagram of the steel sleeve, offset ring, and water-stop ring structure;

[0026] Figure 4 This is a schematic diagram of the groove and the water-swellable rubber strip structure.

[0027] Legend:

[0028] 1. Timber; 2. Bamboo plywood; 3. Concrete; 4. Steel pipe; 5. Mountain-shaped clamp; 6. Nut; 7. Tie rod; 8. Steel sleeve; 9. Offset ring; 10. Water-stop ring; 11. Sponge strip; 12. Groove; 13. Water-swellable rubber strip. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] Example 1, refer to Figures 1-4 A prefabricated casing and formwork structure for underground construction includes a casing assembly, a formwork assembly, and a fastening assembly. The casing assembly includes a steel casing 8, an offset ring 9, and a water-stop ring 10. The formwork assembly includes timber 1, a steel pipe 4, and bamboo plywood 2. The fastening assembly includes U-shaped clips 5, nuts 6, and tie rods 7. The water-stop ring 10 is welded to the middle of the steel casing 8, and two offset rings 9 are respectively welded to both sides of the steel casing 8. The three components are firmly welded to form an integrated structure, which not only strengthens the overall structural stability but also lays the foundation for subsequent sealing and waterproofing. Timber 1... The bamboo plywood 2 is laid on the outside of the template, and the steel pipe 4 is installed on the outside of the wooden block 1. Together, they form a rigid template support frame. The tie rod 7 runs horizontally through the template assembly and is locked at both ends by the mountain-shaped clip 5 and the nut 6. It can form a balanced bidirectional tensile force to resist the lateral pressure of concrete pouring. The bamboo plywood 2 is tightly attached to the outside of the eccentric ring 9. A sponge strip 11 is sandwiched between the eccentric ring 9 and the bamboo plywood 2. The elastic deformation of the sponge strip 11 fills the tiny gaps in the bonding surface, prevents grout leakage during pouring, and ensures that the concrete can be fully vibrated and compacted.

[0031] Example 2, refer to Figures 1-4Based on Embodiment 1, grooves 12 are provided on both ends of the water-stop ring 10. Water-swellable rubber strips 13 are embedded in the grooves 12. The water-swellable rubber strips 13 have the property of self-swelling when exposed to water. After contact with water, they will expand rapidly and tightly fill the gap between the grooves 12 and the concrete, forming an active waterproof barrier. Together with the water-stop ring 10 and the offset ring 9, they form multiple waterproof defense lines, completely changing the traditional single waterproof logic and greatly improving the long-term effectiveness and reliability of waterproofing.

[0032] Both the water-stop ring 10 and the offset ring 9 are vertically welded to the steel sleeve 8 to ensure the verticality and tightness of the connection, thus enhancing the sealing and leak-proof effect. The timber 1 is laid evenly at intervals along the length of the bamboo plywood 2, providing evenly distributed support and preventing excessive local stress that could cause the formwork to deform. The steel pipe 4 is set along the length of the timber 1 and fits tightly against it, further enhancing the overall rigidity of the formwork system and ensuring that the formwork remains flat and stable under the lateral pressure generated by concrete pouring.

[0033] The outer diameter of the offset ring 9 is 50mm and the thickness is 5mm. The thickness of the water-stop ring 10 is 8mm, and the outer diameter of the water-stop ring 10 is larger than that of the offset ring 9. The sufficient thickness gives the water-stop ring 10 strong water-blocking strength, and the larger outer diameter forms a stepped water-blocking structure, which significantly extends the seepage path and improves the waterproof redundancy.

[0034] Example 3, refer to Figures 1-4 Based on Embodiment 1 or Embodiment 2, a construction method for prefabricated underground sleeve and formwork structures includes the following steps:

[0035] S1: Process the steel sleeve 8 according to the pipeline diameter requirements in the drawings, process the grooves 12 on both ends of the water-stop ring 10, weld the water-stop ring 10 to the middle of the steel sleeve 8, weld the offset ring 9 to both sides of the steel sleeve 8, and then install the water-swellable rubber strip 13 in the groove 12 to make an assembled sleeve. Through factory prefabrication, ensure the precise connection of each component, reduce on-site operation errors and construction difficulty;

[0036] S2: Position the prefabricated sleeve according to the plane coordinates, elevation coordinates and elevation of the design drawings, and weld it to the wall reinforcement to ensure that the center line of the steel sleeve 8 is perpendicular to the wall surface. This provides an accurate benchmark for subsequent pipeline connection, formwork installation and concrete pouring, and avoids positioning deviation from affecting the quality of the project.

[0037] S3: Lay wooden strips 1 on the outside of bamboo plywood 2, and then install steel pipes 4 on the outside of wooden strips 1. Secure the template components with matching fastening components, and at the same time, make bamboo plywood 2 and the offset ring 9 fit tightly together to further ensure the sealing and leak-proof effect, and make the template system form a stable whole.

[0038] S4: Pour concrete 3 into the formwork and vibrate it thoroughly so that the concrete 3 can tightly fill all the gaps around the sleeve. After the concrete 3 has solidified and reached the specified strength, remove the formwork to avoid structural damage caused by premature formwork removal. Continuously cure the concrete 3 to promote steady strength improvement.

[0039] Before welding the offset ring 9 and the water-stop ring 10 in S1, the welding position line is marked on the surface of the steel sleeve 8 to ensure accurate welding position. This provides a key prerequisite for the effective functioning of sealing and waterproofing and template support, and improves the finished product qualification rate of the prefabricated sleeve.

[0040] The fastening components in S3 are U-shaped clips 5, nuts 6, and tie rods 7. The tie rods 7 pass horizontally through the bamboo plywood 2, the timber 1, and the steel pipe 4. After the steel pipe 4 is clamped by the U-shaped clips 5 at both ends, the nuts 6 are used to lock it to form a bidirectional tension, which prevents the template from deforming during pouring. The U-shaped clips 5 can accurately clamp the steel pipe 4 and avoid slippage of the locking force. The balanced tension formed after the nuts 6 are tightened can accurately offset the lateral pressure generated by the concrete pouring, firmly fix the template system, and at the same time maintain the tight fit between the offset ring 9 and the bamboo plywood 2.

[0041] In S3, a sponge strip 11 is sandwiched between the tightly fitting surfaces of the bamboo plywood 2 and the offset ring 9. The sponge strip 11 seals the overlap gap between the bamboo plywood 2 and the offset ring 9, preventing grout leakage. The sponge strip 11, the offset ring 9, and the bamboo plywood 2 form a tight sealing interface, which will not fall off due to construction vibration or template displacement. Its compressibility can also adapt to minor errors in construction. Even if there are slight deviations in template processing or installation, it can achieve effective sealing through deformation, improving the construction error tolerance rate.

[0042] After S4 is poured, wait for concrete 3 to solidify and reach the specified strength, then remove the formwork and cure concrete 3 to ensure structural stability and waterproofing effect. Removing the formwork after reaching the specified strength can prevent concrete 3 from cracking or deforming due to insufficient strength, and ensure tight bonding with the sleeve assembly. Continuous moist curing can prevent the surface of concrete 3 from losing water and causing shrinkage cracks, and prevent cracks from becoming water seepage channels. Ultimately, concrete 3 and sleeve assembly form a solid integrated structure, extending the service life of waterproofing and structure.

[0043] During the formwork reinforcement stage, the tie rod 7 runs horizontally through the entire formwork system and the concrete pouring area. When the formwork is removed after the concrete has solidified to the specified strength, the nut 6 and the mountain-shaped clip 5 will be disassembled and recycled first. The tie rod 7, because it is tightly wrapped by the solidified concrete, has formed a stable integrated structure with the wall and does not need to be removed. The excess part of the tie rod 7 exposed on the wall surface needs to be cut off and removed using a cutting machine.

[0044] Working principle: The steel sleeve 8 serves as the core load-bearing component for pipelines passing through the wall, providing stable installation support and structural protection for the pipelines. A water-stop ring 10 is vertically welded to its center, and two offset rings 9 are vertically welded to each side. These three components are firmly welded together to form an integrated structure. In the formwork assembly, timber 1 is laid evenly at intervals along the length of bamboo plywood 2, and steel pipe 4 is set along the length of timber 1 and tightly fitted to it. The tie rods 7 of the fastening assembly transversely penetrate the bamboo plywood 2, timber 1, and steel pipe 4. Both ends are secured with U-shaped clips 5 and then locked with nuts 6, forming a continuous bidirectional tensile force that effectively counteracts the lateral pressure generated during concrete pouring, preventing deformation and displacement of the formwork assembly. The outer side of the offset ring 9 is tightly bonded to the bamboo plywood 2. The sponge strip 11 sandwiched between the two fully fills the tiny gaps between the bonding surfaces through its elastic deformation properties, preventing the leakage of cement slurry during the pouring of concrete 3, and reducing the hard contact wear between the bamboo plywood 2 and the offset ring 9. Before the bamboo plywood 2 and the offset ring 9 are tightly bonded, the sponge strip 11 is glued to the outer side of the offset ring 9 to initially fix its position. The grooves 12 opened on both ends of the water-stop ring 10 are fitted with water-swellable rubber strips 13. The water-swellable rubber strips 13 are tightly bonded to the inner wall of the grooves 12. When external water seeps in, they will actively expand and tightly fill the gap between the grooves 12 and the concrete 3, forming an active waterproof barrier. Ultimately, the offset ring 9, the water-stop ring 10, and the water-swellable rubber strip 13 form multiple longitudinally distributed waterproof lines on the steel sleeve 8. When water attempts to seep in, it must bypass the outer offset ring 9, the concrete 3 filling layer, the water-stop ring 10, the water-swellable rubber strip 13, and the inner offset ring 9, significantly extending the seepage path, greatly reducing the risk of leakage, and achieving the dual effect of long-term waterproofing and structural protection.

[0045] During the processing and preparation stage, the steel sleeve 8 is precisely cut and processed according to the pipeline diameter in the drawings. Before welding the offset ring 9 and the water-stop ring 10, the welding position line is marked on the surface of the steel sleeve 8 to ensure the accuracy of the welding position. Grooves 12 are processed on both ends of the water-stop ring 10, and water-swellable rubber strips 13 are embedded in the grooves 12 to lay a solid foundation for subsequent waterproof performance. During the positioning and installation stage, the prefabricated sleeve is precisely positioned according to the plane coordinates, elevation coordinates and elevation of the design drawings, and welded and fixed to the wall reinforcement. The center line of the steel sleeve 8 is kept perpendicular to the wall surface to ensure the accuracy of the benchmark for pipeline connection, formwork installation and concrete 3 pouring. During the formwork reinforcement stage, wooden blocks 1 and steel pipes 4 are laid in sequence on the outside of the bamboo plywood 2. Through the coordinated locking of tie rods 7, U-shaped clips 5 and nuts 6, a balanced two-way reinforcement force is formed, which not only ensures the flatness and stability of the formwork system, but also maintains the tight fit between the offset ring 9 and the bamboo plywood 2. At the same time, sponge strips 11 are clamped on the bonding surface of the two and cover the overlapping area to further block the grout leakage channel. During the pouring and curing stage, concrete 3 is poured into the formwork and vibrated thoroughly. Under the constraint of the formwork system, the concrete 3 flows fully around the steel sleeve 8, the offset ring 9, the water-stop ring 10 and the water-swellable rubber strip 13 and fills all gaps to form a dense structural bonding surface. After the concrete 3 has solidified to the specified strength, the formwork is removed, and then the concrete 3 is continuously moistened and cured to continuously exert stable sealing, waterproofing and structural protection functions.

Claims

1. A prefabricated casing and formwork structure for underground construction, comprising a casing assembly, a formwork assembly, and a fastening assembly, characterized in that: The sleeve assembly includes a steel sleeve (8), an offset ring (9) and a water-stop ring (10); the template assembly includes a timber (1), a steel pipe (4) and a bamboo plywood (2); and the fastening assembly includes a mountain-shaped clip (5), a nut (6) and a tie rod (7). The water-stop ring (10) is welded to the middle of the steel sleeve (8), and the two offset rings (9) are respectively welded to the two sides of the steel sleeve (8). The wooden block (1) is laid on the outside of the bamboo plywood (2), and the steel pipe (4) is installed on the outside of the wooden block (1). The tie rod (7) passes through the template assembly laterally and is locked and fixed at both ends by the mountain-shaped clip (5) and the nut (6). The bamboo plywood (2) is tightly attached to the outside of the offset ring (9), and a sponge strip (11) is sandwiched between the offset ring (9) and the bamboo plywood (2).

2. The prefabricated casing and formwork structure for underground buildings according to claim 1, characterized in that: The water-stop ring (10) has grooves (12) on both ends, and water-swellable rubber strips (13) are embedded in the grooves (12).

3. The prefabricated casing and formwork structure for underground buildings according to claim 1, characterized in that: Both the water-stop ring (10) and the offset ring (9) are welded and fixed perpendicularly to the steel sleeve (8).

4. The prefabricated casing and formwork structure for underground buildings according to claim 1, characterized in that: The timber (1) is laid at even intervals along the length of the bamboo plywood (2), and the steel pipe (4) is set along the length of the timber (1) and is tightly fitted to the timber (1).

5. The prefabricated casing and formwork structure for underground buildings according to claim 1, characterized in that: The outer diameter of the deflecting ring (9) is 45mm to 60mm and the thickness is 3 to 5mm; the thickness of the water-stopping ring (10) is not less than 5mm and the outer diameter of the water-stopping ring (10) is greater than the outer diameter of the deflecting ring (9).

6. A construction method for prefabricated underground sleeve and formwork structures in buildings, characterized in that: Includes the following steps: S1: Process the steel sleeve (8), water-stop ring (10), and offset ring (9). Process grooves (12) on both ends of the water-stop ring (10), and weld the water-stop ring (10) to the middle of the steel sleeve (8). Weld the offset ring (9) to both sides of the steel sleeve (8). Then install water-swellable rubber strips (13) in the grooves (12) to make an assembled sleeve assembly. S2: Weld the sleeve assembly to the wall reinforcement to ensure that the center line of the steel sleeve (8) is perpendicular to the wall surface; S3: Lay a wooden strip (1) on the outside of the bamboo plywood (2), and then install a steel pipe (4) on the outside of the wooden strip (1). Secure the template assembly with the matching fastening components, and at the same time, make the bamboo plywood (2) and the eccentric ring (9) fit tightly together to further ensure the sealing and leak-proof effect. S4: Pour concrete (3) into the template and vibrate it thoroughly. After the concrete (3) has solidified to the specified strength, remove the template and continue to cure the concrete (3).

7. A construction method for a prefabricated underground casing and formwork structure according to claim 6, characterized in that: Before welding the offset ring (9) and the water-stop ring (10) in S1, mark the welding position line on the surface of the steel sleeve (8) to ensure accurate welding position.

8. A construction method for a prefabricated underground casing and formwork structure according to claim 6, characterized in that: The fastening components in S3 are a mountain-shaped clamp (5), a nut (6) and a tie rod (7). The tie rod (7) passes horizontally through the bamboo plywood (2), the timber (1) and the steel pipe (4). After the steel pipe (4) is clamped by the mountain-shaped clamp (5) at both ends, it is locked with the nut (6) to form a bidirectional tension to prevent the template from deforming during pouring.

9. A construction method for a prefabricated underground sleeve and formwork structure according to claim 6, characterized in that: In S3, a sponge strip (11) is sandwiched between the tightly fitting surfaces of the bamboo plywood (2) and the eccentric ring (9). The sponge strip (11) seals the gap between the bamboo plywood (2) and the eccentric ring (9) to prevent grout leakage.

10. A construction method for a prefabricated underground casing and formwork structure according to claim 6, characterized in that: After S4 is poured, once the concrete (3) has solidified to the specified strength, the formwork is removed and the concrete (3) is cured to ensure structural stability and waterproofing.

Images