Formwork-removal-free integrated forming construction method for small pit-in-pit of basement

Abstract

The invention provides a basement small pit-in-pit formwork-removal-free integrated forming construction method. The basement small pit-in-pit formwork-removal-free integrated forming construction method comprises the following steps that S1, pit-in-pit steel bars are reinforced and welded; s2, placing a channel steel frame at the bottom of the pit in the pit, and welding and fixing the channel steel frame with surrounding steel bars; s3, a prefabricated bottom plate is installed on the channel steel frame, and a vertical rod is installed; s4, transverse rods are welded to the vertical rods to form a positioning frame, and then prefabricated wallboards are assembled on the positioning frame; s5, L-shaped steel connecting pieces are arranged on the inner sides of the prefabricated wallboards so that the prefabricated wallboards can be locked; s6, after all the four wall bodies in the well are installed, perpendicularity correction is conducted on the corners of every two adjacent prefabricated wall plates; s7, a prefabricated well frame is installed at the top of the prefabricated wall plate; and S8, after concrete pouring is completed, the tool used for correcting the perpendicularity in the step S6 and the L-shaped steel connecting piece in the step S5 are dismantled. The pit-in-pit structure reinforcing steel bars are connected with the channel steel frame in a welded mode, the prefabricated wallboards are spliced, a non-dismantling formwork system structure is used as a part of a main body structure, and the problems that a pit-in-pit box formwork floats upwards, expands and the like can be solved.

Description

Technical Field

[0001] The present application relates to the field of building construction technology, and in particular to a method for constructing a small basement pit-in-pit without removing the mold and forming an integrated structure. Background Art

[0002] With the increasing number of high-rise buildings, underground structures are often constructed, requiring the excavation of deeper "pits within pits" at the bottom of foundation pits. Construction in these pits is challenging, and traditional formwork systems are prone to a series of problems, including collapse and overturning of the pit walls, floating of the pit bottom, tilting of the formwork support system, loose concrete pouring of the pit floor, and water leakage, all of which are extremely detrimental to ensuring the quality of the basement floor.

[0003] For example, in traditional construction methods, prefabricated box-shaped formwork with an integral bottom cover is usually set up during the basement floor construction phase according to the plane size and height difference of the basement pit. It serves as the internal support formwork for the pit-in-pit area. Concrete is poured from the side of the box formwork and flows to the bottom of the pit. Air holes are reserved on the bottom formwork or the top of the box formwork is weighed to prevent the box formwork from floating up during the concrete pouring process. The formwork is removed after the concrete pouring is completed.

[0004] This method will cause many problems: the pit bottom elevation is difficult to effectively control, and the box mold may even float up, and the internal support system will be unstable, causing serious quality hazards and water leakage risks in this area. Summary of the Invention

[0005] In order to improve the problem that the box mold is easy to float up and the internal support system is unstable during the existing pit-in-pit casting, the present application provides an integrated molding construction method for a small basement pit-in-pit without removing the mold.

[0006] The present application provides a method for constructing a small basement pit-in-pit without removing the formwork and adopts the following technical solutions: A method for constructing a small basement pit-in-pit without removing the mold, comprising the following steps: S1. After the basement floor reinforcement is tied, perform pit-in-pit reinforcement welding; S2. Measure and locate the pit bottom, place a channel steel frame at the pit bottom at the pit point, and weld it to the surrounding steel bars; S3. Install the prefabricated base plate on the channel steel frame and install poles around the channel steel frame; S4 welded crossbars on the uprights to form a positioning frame, and then assembled prefabricated wall panels on the positioning frame; S5. An L-shaped steel connector is provided on the inside of the prefabricated wall panel to lock the prefabricated wall panel; S6. After all four walls in the well are installed, perform vertical alignment on the corners of two adjacent prefabricated wall panels. S7. Install the prefabricated well frame on top of the prefabricated wall panel and lock it; S8. After the concrete pouring is completed and the demoulding strength is reached, the tool used to correct the verticality in step S6 and the L-shaped steel connector in step S5 can be removed.

[0007] Furthermore, a plurality of bottom plate connection blocks are fixedly connected to the upper end surface of the channel steel frame, and a plurality of connection holes corresponding one-to-one with the plurality of bottom plate connection blocks are opened on the prefabricated bottom plate.

[0008] Furthermore, a plurality of positioning ribs are fixedly connected to the outer periphery of the channel steel frame, and the plurality of vertical poles are plugged and matched with the plurality of positioning ribs one by one.

[0009] Furthermore, the L-shaped steel connector is provided with a plurality of fixing bolts passing through the prefabricated wall panel, and at least one fixing bolt is provided at the end of the L-shaped steel connector.

[0010] Furthermore, the tool for correcting verticality in step S6 includes a corner wedge, and both side walls perpendicular to each other are provided with slots that are adapted to be inserted into the fixing bolt rods; when the corner wedge is attached to the corners of two adjacent prefabricated wall panels, the two slots on the corner wedge respectively correspond to the two fixing bolt rods on the two L-shaped steel connectors.

[0011] Furthermore, the two adjacent inner corner sides of the corner wedge block are set as wedge surfaces, and the end with smaller thickness is close to the opening end of the slot.

[0012] Furthermore, an embedding groove is provided on the inner side wall of the prefabricated wall panel near the corner, and the wall of another prefabricated wall panel near the corner is plugged into and matched with the embedding groove, or is fixed with an embedding block that is embedded and matched with the embedding groove.

[0013] Furthermore, the prefabricated wall panels are spliced ​​together by multiple connecting plates, and the adjacent ends of the two spliced ​​connecting plates are provided with L-shaped interfaces for use together, one of the L-shaped interfaces is fixedly connected to a connecting plug, and the other L-shaped structure is fixedly connected to a connecting socket for use with the connecting plug, and holes are penetrated on the connecting socket and the connecting plug.

[0014] Furthermore, the prefabricated well frame is sleeved on the outer periphery of the top of the four prefabricated wall panels.

[0015] Furthermore, the prefabricated well frame is formed by welding angle steels, and a clamping bolt is passed through a horizontal thread on a vertical side thereof, and a gasket is installed at one end of the clamping bolt that is in contact with the outer wall of the prefabricated wall panel.

[0016] In summary, this application includes at least one of the following beneficial technical effects: 1. By utilizing the welded connection between the pit-in-pit structural reinforcement and the channel steel frame, the non-disassembly formwork system structure is treated as part of the main structure, avoiding the problems of traditional technology that require the installation of formwork, internal support wood, and weight inside the pit. The precast wall panels are clamped by L-shaped steel connectors and positioning frames to ensure that the precast wall panels are connected stably and firmly, with balanced force. This overcomes the problem of the traditional pit-in-pit box formwork floating, the lateral pressure of concrete, and the vibration that causes the formwork to expand, and ensures that the precast wall panels are connected stably and firmly, with balanced force. 2. The corner wedge design effectively corrects the verticality of precast wall panel connections, overcoming the problem of formwork installation tilt and misalignment that is often encountered with similar technologies and lacks effective control methods. Secondly, the precast manhole frame is installed during the precast wall panel construction phase, providing an adjustable mechanism that eliminates the need for secondary on-site installation and can be formed integrally during concrete pouring. 3. By interlocking the two prefabricated wall panels at the corners, the connection between the components is made tighter, which can significantly improve the structural stability of the corners and effectively solve the problem of leakage in the joints of the components; 4. By using a combination of L-shaped interfaces and connecting plugs between the connecting plates, the problem that the existing non-dismantling formwork size is fixed and cannot be adjusted can be solved, and the non-dismantling formwork system construction function for pits of different sizes can be realized. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 This is a schematic diagram of steel bar binding in a pit in an embodiment of the present application; Figure 2 This is a structural diagram of a channel steel frame according to an embodiment of the present application; Figure 3 This is a schematic diagram of the installation of the prefabricated base plate according to an embodiment of the present application; Figure 4 This is a schematic diagram of the installation of the positioning frame according to the embodiment of the present application; Figure 5 This is a schematic diagram of the installation of a single-sided prefabricated wall panel according to an embodiment of the present application; Figure 6 This is a schematic diagram of the structure after the four walls of the embodiment of the present application are installed; Figure 7 yes Figure 6 A magnified schematic diagram of part A; Figure 8This is a schematic diagram of the assembly of the corner of the prefabricated wall panel in the embodiment of the present application; a is provided with only the embedding groove, and b is provided with the embedding groove and the embedding block; Figure 9 This is a structural diagram of prefabricated wall panels spliced ​​with connecting plates according to an embodiment of the present application; Figure 10 yes Figure 9 An enlarged schematic diagram of part B; Figure 11 This is a schematic diagram of the installation of a prefabricated well frame according to an embodiment of the present application; Figure 12 This is a schematic diagram of the installation of a prefabricated well frame compressed by a compression bolt according to an embodiment of the present application.

[0019] Reference numerals: 1. Channel steel frame; 11. Bottom plate connecting block; 12. Positioning ribs; 2. Prefabricated base plate; 21. Connection hole; 3. Positioning frame; 31. Vertical pole; 32. Crossbar; 4. Prefabricated wall panels; 41. Grooving; 42. Blocks; 51. L-shaped steel connector; 52. Fixing bolt; 6. Prefabricated well frame; 61. Compression bolt; 62. Gasket; 7. Corner wedge; 71. Card slot; 8. Connecting plate; 81. L-shaped interface; 82. Connecting plug; 83. Connecting socket; 91. Bottom plate reinforcement; 92. Pit-in-pit reinforcement. DETAILED DESCRIPTION

[0020] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0021] Reference Figures 1-12 The present application discloses a method for constructing a small basement pit-in-pit without removing the mold, which includes the following steps: S1. After the basement floor steel bars 91 are tied, the pit-in-pit steel bars 92 are reinforced and welded.

[0022] S2. Measure and locate at the bottom of the pit, place a channel steel frame 1 at the bottom of the pit-in-pit point and weld it to the surrounding pit-in-pit reinforcement 92; wherein the channel steel frame 1 is made of multiple channel steels welded in a crisscross pattern, and multiple bottom plate connecting blocks 11 are fixed to the upper end surface of the channel steel frame 1. The prefabricated bottom plate 2 is provided with multiple connecting holes 21 that correspond one-to-one with the multiple bottom plate connecting blocks 11. Figure 2 and Figure 3 shown.

[0023] S3. Install the prefabricated bottom plate 2 on the channel steel frame 1, so that the bottom plate connecting blocks 11 on the channel steel frame 1 are inserted into the connecting holes 21 on the prefabricated bottom plate 2 to position the prefabricated bottom plate 2. Then install the vertical rods 31 around the channel steel frame 1. Specifically, the outer periphery of the channel steel frame 1 is fixed with multiple positioning ribs 12, and the multiple vertical rods 31 are plugged and adapted to the multiple positioning ribs 12 one by one. Figure 3 and Figure 4 shown.

[0024] S4. Welding the crossbar 32 on the uprights 31 to reinforce the uprights 31 and forming a positioning frame 3, and then assembling the prefabricated wall panels 4 on the positioning frame 3, such as Figure 4 and Figure 5 shown.

[0025] S5. An L-shaped steel connector 51 is provided on the inner side of the prefabricated wall panel 4 from bottom to top. The L-shaped steel connector 51 is provided with a plurality of fixing bolts 52 that penetrate the prefabricated wall panel 4 to lock the prefabricated wall panel 4 on the positioning frame 3. At least one fixing bolt 52 is provided at the end of the L-shaped steel connector 51. Figure 5 and Figure 6 shown.

[0026] S6. After the four walls in the well are installed, the verticality of the corners of the two adjacent prefabricated wall panels 4 is corrected. The tool for correcting the verticality includes a corner wedge 7, and the two perpendicular walls of the corner wedge 7 are provided with a slot 71 that is adapted to be inserted into the rod of the fixing bolt 52; when the corner wedge 7 is fitted to the corners of the two adjacent prefabricated wall panels 4, the two slots 71 on the corner wedge 7 respectively correspond to the two rods of the fixing bolts 52 on the two L-shaped steel connectors 51. The two adjacent inner corner sides of the corner wedge 7 are set as wedge surfaces, and the end with smaller thickness is close to the open end of the slot 71. During the specific correction, the verticality of the corner and the wall is corrected by hammering the corner wedge 7, such as Figure 6 and Figure 7 shown.

[0027] S7. Install the prefabricated well frame 6 on the top of the prefabricated wall panel 4 and lock it. Specifically, the prefabricated well frame 6 is sleeved on the outer periphery of the top of the four prefabricated wall panels 4; and the prefabricated well frame 6 is welded from angle steel, and a clamping bolt 61 is passed through the horizontal thread on its vertical edge. A gasket 62 is installed on one end of the clamping bolt 61 that fits against the outer wall of the prefabricated wall panel 4, and each side of the prefabricated well frame 6 has at least two clamping bolts 61. After the prefabricated well frame 6 is sleeved on the outside of the top of the prefabricated wall panel 4, the gasket 62 on it is pressed against the outer wall of the prefabricated wall panel 4 by rotating the clamping bolt 61, thereby achieving a locking effect on the outer side of the prefabricated wall panel 4, such as Figure 11 and Figure 12 shown.

[0028] S8. After the concrete pouring is completed and the demoulding strength is reached, for example, the concrete strength reaches 80% of the design strength, the tool for correcting the verticality in step S6 and the L-shaped steel connector 51 in step S5 can be removed; specifically, after loosening the fixing bolts 52, the corner wedge 7 and the L-shaped steel connector 51 are removed in sequence for reuse next time.

[0029] Thus, by utilizing the welded connection between the pit-in-pit structural reinforcement and the channel steel frame 1, the non-disassembly formwork system structure is treated as part of the main structure, avoiding the problems of traditional technology requiring the installation of formwork, internal support wood, and weight in the pit. The L-shaped steel connector 51 and the positioning frame 3 clamp the prefabricated wall panels 4, ensuring that the prefabricated wall panels 4 are connected stably and firmly, with balanced force. This overcomes the problem of bulging formwork caused by the floating of the pit-in-pit box formwork in the traditional formwork, the lateral pressure of concrete, and the vibration of the vibration, ensuring that the prefabricated wall panels 4 are connected stably and firmly, with balanced force.

[0030] Furthermore, the design of the corner wedges 7 effectively corrects the verticality of the precast wall panels 4, overcoming the problem of tilted and misaligned formwork installation in similar technologies, which lacks a good control method. Secondly, the precast manhole frame 6 is installed during the construction phase of the precast wall panels 4 without formwork removal. This adjustable feature eliminates the need for secondary on-site installation and allows it to be integrally formed during the concrete pour.

[0031] In addition, to ensure the waterproof performance of the four walls after installation, refer to Figure 8 , a groove 41 is provided on the inner side wall of the prefabricated wall panel 4 near the corner, and another prefabricated wall panel 4 near the corner is plugged into the groove 41 for adaptation. Figure 8 Alternatively, another prefabricated wall panel 4 is fixedly connected to the end surface of the wall near the corner with a fitting insert 42 embedded in the groove 41, as Figure 8 As shown in b.

[0032] Therefore, by interlocking the two prefabricated wall panels 4 at the corner, the connection between the components is made tighter, which can significantly improve the structural stability of the corner and effectively solve the problem of leakage in the joints of the components.

[0033] In addition, for some larger pits, when the prefabricated wall panels 4 are too large, they are not suitable for actual construction conditions. Therefore, in another feasible embodiment, referring to Figure 9 and Figure 10 The prefabricated wall panel 4 is made up of multiple connecting plates 8. The adjacent ends of the two connecting plates 8 are provided with L-shaped interfaces 81 for cooperation. A connecting plug 82 is fixedly connected to one of the L-shaped interfaces 81, and a connecting socket 83 for cooperation with the connecting plug 82 is fixedly connected to the other L-shaped structure. The connecting socket 83 and the connecting plug 82 are respectively provided with matching card holes and wedge-shaped card blocks.

[0034] Therefore, by adopting a combination of L-shaped interfaces 81 and connecting plugs 82 between the connecting plates 8, the problem that the existing non-disassembly formwork size is fixed and cannot be adjusted can be solved, and the non-disassembly formwork system construction function for pits in pits of different sizes can be realized.

[0035] The implementation principle of the method for constructing a small basement pit-in-pit without removing the mold is as follows: By welding the pit-in-pit structural reinforcement to the channel steel frame 1, the non-disassembly formwork system structure is treated as part of the main structure, avoiding the problems of traditional technology requiring formwork, internal support wood, and weighting within the pit. The L-shaped steel connector 51 and the positioning frame 3 clamp the prefabricated wall panels 4, ensuring a stable and firm connection and balanced force on the prefabricated wall panels 4. This overcomes the problem of floating pit-in-pit box formwork in traditional methods, and the bulging of the formwork due to lateral pressure from concrete and vibration from compaction, ensuring a stable and firm connection and balanced force on the prefabricated wall panels 4.

[0036] Furthermore, the design of the corner wedges 7 effectively corrects the verticality of the precast wall panels 4, overcoming the problem of tilted and misaligned formwork installation in similar technologies, which lacks a good control method. Secondly, the precast manhole frame 6 is installed during the construction phase of the precast wall panels 4 without formwork removal. This adjustable feature eliminates the need for secondary on-site installation and allows it to be integrally formed during the concrete pour.

[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for constructing a small basement pit-in-pit without removing the mold, characterized in that: The following steps are involved: S1. After the basement floor reinforcement is tied, perform pit-in-pit reinforcement welding; S2. Measure and locate the pit bottom, place a channel steel frame at the pit bottom at the pit point, and weld it to the surrounding steel bars; S3. Install the prefabricated base plate on the channel steel frame and install poles around the channel steel frame; S4 welded crossbars on the uprights to form a positioning frame, and then assembled prefabricated wall panels on the positioning frame; S5. An L-shaped steel connector is provided on the inside of the prefabricated wall panel to lock the prefabricated wall panel; S6. After all four walls in the well are installed, perform vertical alignment on the corners of two adjacent prefabricated wall panels. S7. Install the prefabricated well frame on top of the prefabricated wall panel and lock it; S8. After the concrete pouring is completed and the demoulding strength is reached, the tool used to correct the verticality in step S6 and the L-shaped steel connector in step S5 can be removed.

2. The method for constructing a small basement pit-in-pit without removing the mold according to claim 1, characterized in that: A plurality of bottom plate connection blocks are fixedly connected to the upper end surface of the channel steel frame, and a plurality of connection holes corresponding to and plugging into the plurality of bottom plate connection blocks are opened on the prefabricated bottom plate.

3. The method for constructing a small basement pit-in-pit without removing the mold according to claim 1, characterized in that: A plurality of positioning ribs are fixedly connected to the outer periphery of the channel steel frame, and the plurality of vertical poles are plugged and adapted to the plurality of positioning ribs one by one.

4. The method for constructing a small basement pit-in-pit without removing the mold according to claim 1, characterized in that: The L-shaped steel connector is provided with a plurality of fixing bolts penetrating the prefabricated wall panels, and at least one fixing bolt is provided at the end of the L-shaped steel connector.

5. The method for constructing a small basement pit-in-pit without removing the mold as claimed in claim 4, characterized in that: The tool for correcting verticality in step S6 includes a corner wedge, and both side walls perpendicular to each other are provided with slots that are adapted to be inserted into the fixing bolt rods; when the corner wedge is attached to the corners of two adjacent prefabricated wall panels, the two slots on the corner wedge respectively correspond to the two fixing bolt rods on the two L-shaped steel connectors.

6. The method for constructing a small basement pit-in-pit without removing the mold as claimed in claim 5, characterized in that: The two adjacent inner corner sides of the corner wedge block are set as wedge surfaces, and the end with smaller thickness is close to the opening end of the slot.

7. The method for constructing a small basement pit-in-pit without removing the mold according to claim 1, characterized in that: The inner side wall of the prefabricated wall panel near the corner is provided with an embedding groove, and the wall body of another prefabricated wall panel near the corner is plugged into and matched with the embedding groove, or is fixed with an embedding block that is embedded and matched with the embedding groove.

8. The method for constructing a small basement pit-in-pit without removing the mold as claimed in claim 1, characterized in that: The prefabricated wall panels are made up of multiple connecting plates, and the adjacent ends of the two connecting plates are provided with L-shaped interfaces for use with each other. A connecting plug is fixedly connected to one of the L-shaped interfaces, and a connecting socket for use with the connecting plug is fixedly connected to the other L-shaped structure. Holes are penetrated on both the connecting socket and the connecting plug.

9. The method for constructing a small basement pit-in-pit without removing the mold as claimed in claim 1, characterized in that: The prefabricated well frame is sleeved on the outer periphery of the top of the four prefabricated wall panels.

10. The method for constructing a small basement pit-in-pit without removing the mold as claimed in claim 9, characterized in that: The prefabricated well frame is formed by welding angle steels, and a clamping bolt is passed through a horizontal thread on a vertical side thereof, and a gasket is installed at one end of the clamping bolt that is in contact with the outer wall of the prefabricated wall panel.

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