Rectangular pipe jacking backrest structure and its construction method

Abstract

The present invention discloses a rectangular pipe jacking backrest structure and its construction method. The structure includes: a falling bottom plate having a first end close to the connecting passage and a second end far from the connecting passage; and a space frame including structural plates and multiple frame columns. The multiple frame columns are cast at the second end of the falling bottom plate. The structural plates include an original bottom plate with an elevation higher than that of the falling bottom plate and multiple layers of floor bearing plates arranged above the original bottom plate. The original bottom plate and the multiple layers of floor bearing plates are connected to the side of the multiple frame columns far from the falling bottom plate. The position of the lowermost floor bearing plate corresponds to the upper part of the reaction frame, and the lowermost floor bearing plate is connected to the middle parts of the multiple frame columns through concealed beams. The outer diameter of the column section of the frame column between the original bottom plate and the lowermost floor bearing plate is larger than the outer diameters of the remaining column sections of the frame column. The present invention solves the problem of poor economy of traditional construction when pipe jacking excavation construction is adopted for the connecting passage between two underground structures.

Description

Technical Field

[0001] The present invention relates to the technical field of building construction, and particularly relates to a rectangular pipe jacking backrest structure and a construction method thereof. Background Art

[0002] An underground garage connecting passage is designed between some adjacent building structures. When excavating the connecting passage by using the rectangular pipe jacking technology, it is necessary to coordinate the construction sequence of the connecting passage and the basement of the main structure.

[0003] If the connecting passage is constructed first, a pipe jacking launching shaft needs to be built, and the launching shaft and its lining are demolished after the construction of the connecting passage is completed. If the main basement is constructed first, a pipe jacking working hole needs to be reserved on the top slab of the basement and a back reaction structure needs to be constructed on the basement floor slab.

[0004] Both methods inevitably require the demolition of the back reaction structure after its use, which causes waste of concrete materials on the one hand, and on the other hand, the construction and curing of the cast-in-place structure to reach the service strength also occupy the construction period. The above two points make the overall economy of the traditional scheme poor.

[0005] The information disclosed in this background art section is only intended to increase the understanding of the overall background of the present invention, and should not be regarded as an admission or any form of suggestion that this information constitutes the prior art known to those of ordinary skill in the art. Summary of the Invention

[0006] In order to overcome the defects existing in the prior art, the present invention provides a rectangular pipe jacking backrest structure and a construction method thereof to solve the problem of poor economy of the traditional construction when excavating the connecting passage between two underground structures by pipe jacking.

[0007] To achieve the above object, a rectangular pipe jacking backrest structure is provided, including:

[0008] A falling bottom plate for placing the reaction frame of the rectangular pipe jacking, the falling bottom plate having a first end close to the connecting passage and a second end far from the connecting passage; and

[0009] A space frame, including a structural plate and multiple frame columns for abutting against the reaction frame. The multiple frame columns are cast at the second end of the falling bottom plate. The structural plate includes an original bottom plate with a level higher than that of the falling bottom plate and multiple floor bearing plates arranged above the original bottom plate. The original bottom plate and the multiple floor bearing plates are connected to the side of the multiple frame columns far from the falling bottom plate. The position of the lowermost floor bearing plate corresponds to the upper part of the reaction frame, and the lowermost floor bearing plate is connected to the middle parts of the multiple frame columns through concealed beams. The outer diameter of the column section of the frame column between the original bottom plate and the lowermost floor bearing plate is larger than the outer diameter of the remaining column sections of the frame column.

[0010] Furthermore, a first haunch is formed by casting between the end face of the second end of the original bottom plate and the falling bottom plate.

[0011] Furthermore, the concealed beam is arranged on the side of the plurality of frame columns away from the falling bottom plate.

[0012] Furthermore, a thickening layer is formed by casting on the side of the column section of the frame column located between the original bottom plate and the bottommost floor bearing plate away from the falling bottom plate. Reinforcing bars are embedded in the thickening layer and extend into the column section.

[0013] Furthermore, a second haunch is cast between the bottommost floor bearing plate and the thickening layer.

[0014] The present invention provides a construction method for a rectangular pipe jacking backrest structure. The underground structure is constructed first, and then the connecting passage is constructed. When constructing the underground structure, the falling bottom plate and the space frame are integrally cast, so that the plurality of frame columns of the space frame are cast at the second end of the falling bottom plate. The original bottom plate of the structural slab of the space frame and the multiple floor bearing plates are connected to the side of the plurality of frame columns away from the falling bottom plate, and the elevation of the falling bottom plate is lower than that of the original bottom plate. Among them, the bottommost floor bearing plate is connected to the middle parts of the plurality of frame columns through concealed beams, and the outer diameter of the column section of the frame column located between the original bottom plate and the bottommost floor bearing plate is larger than that of the other column sections of the frame column.

[0015] The beneficial effects of the present invention are as follows. The rectangular pipe jacking backrest structure of the present invention lowers the original bottom plate and the bearing platform of the basement structure close to the connecting passage during the structural design stage, and adjusts the planar positions of the corresponding structural beams, slabs and columns and strengthens them (increasing the cross-section and the amount of reinforcement) after mechanical calculation. Using the main structure as an integrally formed backrest structure for the rectangular pipe jacking, the backrest structure is constructed together with the basement main structure, which has two advantages compared with the traditional backrest manufacturing method: one is that there is no need to demolish it later, saving concrete materials; the other is that it saves the manufacturing and curing time of the backrest structure and the demolition time after the backrest structure is used, improving the economy of the rectangular pipe jacking construction process. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] By reading the detailed description of the non-restrictive embodiments with reference to the following drawings, other features, purposes and advantages of the present application will become more obvious:

[0017] Figure 1 It is a schematic structural diagram of the rectangular pipe jacking backrest structure of the embodiment of the present invention.

[0018] Figure 2Schematic structural diagram of the space frame according to an embodiment of the present invention.

[0019] Figure 3 Schematic structural diagram of the falling bottom plate according to an embodiment of the present invention.

[0020] Figure 4 Schematic structural diagram of the column section of the frame column according to an embodiment of the present invention.

[0021] Figure 5 Schematic diagram of the force on the rectangular pipe jacking rear backrest structure according to an embodiment of the present invention. Detailed implementation manners

[0022] The following further details the present application in conjunction with the drawings and embodiments. It can be understood that the specific embodiments described herein are only for explaining the related invention and not for limiting the invention. Additionally, it should be noted that for the convenience of description, only the parts related to the invention are shown in the drawings.

[0023] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The following will detail the present application with reference to the drawings and in conjunction with the embodiments.

[0024] Refer to Figures 1 to 5 As shown, the present invention provides a rectangular pipe jacking rear backrest structure, including: a falling bottom plate 1 and a space frame.

[0025] Among them, the falling bottom plate 1 is for the reaction frame 3 of the rectangular pipe jacking to rest on. The falling bottom plate 1 has a first end close to the connection passage 5 and a second end far from the connection passage 5.

[0026] The space frame includes a structural plate 21 and multiple frame columns 22. The multiple frame columns 22 are used to abut against the reaction frame.

[0027] The multiple frame columns 22 are cast at the second end of the falling bottom plate 1.

[0028] The structural plate 21 includes an original bottom plate 211 and multiple layers of floor bearing plates 212. Among them, the elevation of the original bottom plate 211 is higher than that of the falling bottom plate 1. The multiple layers of floor bearing plates 212 are arranged above the original bottom plate 211. In this embodiment, the number of floor bearing plates is two layers, including the lowermost floor bearing plate (i.e., the negative second floor roof) and the uppermost floor bearing plate (i.e., the negative first floor roof). The original bottom plate 211 and the multiple layers of floor bearing plates 212 are connected to the side of the multiple frame columns 22 far from the falling bottom plate 1. The position of the lowermost floor bearing plate 212 corresponds to the upper part of the reaction frame. In this embodiment, the top of the reaction frame is flush with the lowermost floor bearing plate. The lowermost floor bearing plate 212 is connected to the middle parts of the multiple frame columns through concealed beams 213. The outer diameter of the column section of the frame column between the original bottom plate 211 and the lowermost floor bearing plate 212 is larger than the outer diameter of the remaining column sections of the frame column.

[0029] In this embodiment, the reaction frame includes a reaction frame body, a rear support plate, an oil cylinder frame, and a base guide rail. The reaction frame body is installed on the lowered floor slab and abuts against multiple frame columns. The base guide rail is installed on the lowered floor slab and is disposed on one side of the reaction frame body away from the frame columns. The oil cylinder frame is installed on one side of the reaction frame body away from the frame columns through the rear support plate and is disposed above the base guide rail.

[0030] Refer to Figure 1 、 Figure 2 and Figure 5 , for the rectangular pipe jacking rear backrest structure of the present invention, the basement floor slab (including its pile cap) at the launching shaft of the rectangular pipe jacking is lowered and poured to form a lowered floor slab. The original floor slab is used as a horizontal support to bear the reaction force of the pipe jacking construction. The reinforcement bars of the original floor slab are increased by calculating and adding a layer of crack-resistant steel mesh on the basis of the original design. The bottommost floor slab (including its structural beams) is used as the second horizontal support to bear another part of the reaction force. The reaction frame abuts against multiple frame columns, so that the pipe jacking oil cylinder frame abuts against the frame columns. A simply supported beam force system is formed through the frame columns, multiple floor slabs, and the original floor slab (as shown in Figure 5 ). By arranging concealed beams in the bottommost floor slab and strengthening the original beam-column structure of the basement structure, a space frame is formed to ensure the reliability of node force transmission.

[0031] The rectangular pipe jacking rear backrest structure of the present invention performs lowering treatment on the original floor slab and pile cap near the connection channel of the basement structure in the structural design stage, and conducts plane position adjustment and strengthening (increasing the section and increasing the reinforcement) after mechanical calculation for the corresponding structural beams, slabs, and columns. Using the main structure as an integrally formed rear backrest structure for the rectangular pipe jacking, the rear backrest structure is constructed together with the basement main structure, which has two advantages compared with the traditional rear backrest manufacturing method: one is that there is no need to demolish it later, saving concrete materials; the other is that it saves the production and maintenance time of the rear backrest structure and the demolition time after the rear backrest structure is used, improving the economy of the rectangular pipe jacking construction process.

[0032] As a preferred embodiment, a first haunch 214 is formed by pouring between the end face of the original floor slab 211 and the second end of the lowered floor slab 1. In this embodiment, the first haunch is formed by haunching the height difference between the original floor slab and the lowered floor slab, thereby reinforcing the overall structure and ensuring the reliability of node force transmission.

[0033] In this embodiment, the concealed beam 213 is disposed on one side of multiple frame columns 22 away from the lowered floor slab 1.

[0034] Refer to Figure 1 、 Figure 2 and Figure 4, a thickening layer 221 is cast on the side of the column section of the frame column located between the original bottom plate 211 and the bottommost floor slab 212 away from the falling bottom plate 1. Reinforcing bars 222 are embedded in the thickening layer. The reinforcing bars 222 extend into the column section.

[0035] As a preferred embodiment, a second haunch 215 is cast between the bottommost floor slab 212 and the thickening layer.

[0036] In view of the construction condition of using the rectangular pipe jacking method for the connection passage between the basements of two main structures, the present invention makes use of the characteristics that the main structure and its pile foundation have a certain horizontal resistance. By lowering the bottom plate and the pile cap of the foundation, the structural bottom plate is used as a horizontal support to bear the reaction force of the pipe jacking construction; meanwhile, the structural floor slab and the structural beam are used as the second horizontal support to bear another part of the reaction force; further, by arranging concealed beams in the floor slab, strengthening the original beam-column structure, and haunching at the height difference between the bottom plate and the floor slab, etc., the overall structure is strengthened to ensure the overall reliability of the backrest structure, enabling the backrest to be constructed together with the main structure without demolition, and improving the economy of the rectangular pipe jacking construction technology.

[0037] The present invention provides a construction method for a rectangular pipe jacking backrest structure. The underground structure is constructed first, and then the connection passage 5 is constructed. When constructing the underground structure, the falling bottom plate 1 and the space frame are integrally cast, so that multiple frame columns 22 of the space frame are cast at the second end of the falling bottom plate 1. The original bottom plate 211 of the structural plate 21 of the space frame and multiple floor slabs 212 are connected to the sides of multiple frame columns 22 away from the falling bottom plate 1, and the elevation of the falling bottom plate 1 is lower than the elevation of the original bottom plate 211. Among them, the bottommost floor slab 212 is connected to the middle parts of multiple frame columns through concealed beams, and the outer diameter of the column section of the frame column located between the original bottom plate 211 and the bottommost floor slab 212 is larger than the outer diameter of the other column sections of the frame column.

[0038] The above description is only the preferred embodiments of the present application and the explanation of the applied technical principles. Those skilled in the art should understand that the scope of the invention involved in the present application is not limited to the technical solutions formed by the specific combination of the above technical features, but also covers other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept. For example, the technical solutions formed by mutually replacing the above features with the (but not limited to) technical features with similar functions disclosed in the present application.

Claims

1. A rectangular pipe jacking backrest structure, characterized in that Comprising: A falling bottom plate for the reaction frame of the rectangular pipe jacking to rest on, the falling bottom plate having a first end close to the connecting passage and a second end far from the connecting passage; And A space frame, including a structural plate and multiple frame columns for abutting against the reaction frame. The multiple frame columns are cast at the second end of the falling bottom plate. The structural plate includes an original bottom plate with an elevation higher than that of the falling bottom plate and multiple floor bearing plates arranged above the original bottom plate. The original bottom plate and the multiple floor bearing plates are connected to one side of the multiple frame columns far from the falling bottom plate. The position of the lowermost floor bearing plate corresponds to the upper part of the reaction frame, and the lowermost floor bearing plate is connected to the middle parts of the multiple frame columns through concealed beams. The outer diameter of the column section of the frame column between the original bottom plate and the lowermost floor bearing plate is larger than the outer diameter of the remaining column sections of the frame column.

2. The rectangular pipe jacking rear backrest structure according to claim 1, characterized in that, A first haunch is cast between the end face of the original bottom plate and the second end of the falling bottom plate.

3. The rectangular pipe jacking rear backrest structure according to claim 1, characterized in that, The concealed beams are arranged on one side of the multiple frame columns far from the falling bottom plate.

4. The rectangular pipe jacking rear backrest structure according to claim 1, characterized in that A thickening layer is cast on the side of the column section of the frame column between the original bottom plate and the lowermost floor bearing plate far from the falling bottom plate. Reinforcing bars are buried in the thickening layer and extend into the column section.

5. The rectangular pipe jacking rear backrest structure according to claim 4, wherein A second haunch is cast between the lowermost floor bearing plate and the thickening layer.

6. A construction method for the rectangular pipe jacking backrest structure according to any one of claims 1 to 5, characterized in that, Construct the underground structure first and then construct the connecting passage. When constructing the underground structure, integrally cast the falling bottom plate and the space frame, so that the multiple frame columns of the space frame are cast at the second end of the falling bottom plate. The original bottom plate of the structural plate of the space frame and the multiple floor bearing plates are connected to one side of the multiple frame columns far from the falling bottom plate, and the elevation of the falling bottom plate is lower than the elevation of the original bottom plate. Among them, the lowermost floor bearing plate is connected to the middle parts of the multiple frame columns through concealed beams. The outer diameter of the column section of the frame column between the original bottom plate and the lowermost floor bearing plate is larger than the outer diameter of the remaining column sections of the frame column.

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