Structure for transforming existing building foundation pit

Abstract

The utility model discloses a structure for transforming an existing building foundation pit, which consists of an existing foundation pit wall body, a bottom plate, a newly-built foundation pit wall body and a bottom plate, the existing bottom plate of a building is dismantled, the newly-built bottom plate is in lap joint with a top steel bar of the existing bottom plate, the newly-built bottom plate sinks 1125mm relative to the existing bottom plate, and the newly-built wall body is arranged on the newly-built bottom plate. The existing foundation pit wall body and the bottom plate are located on one side, the newly-built foundation pit wall body and the bottom plate are located on the other side, and the new foundation pit wall body and the old foundation pit wall body are fixedly connected through force transmission steel bars. The newly-built foundation pit wall body is made of reinforced concrete materials, a plurality of steel bars arranged at certain intervals are arranged in the newly-built foundation pit wall body, and the tops of the steel bars are connected with the bottom of the existing foundation pit wall body through connectors. The existing building foundation pit is transformed, and the connectors are used for connecting the steel bars, so that the operation difficulty of connecting the steel bars is reduced, the construction period is shortened, the occupied space after the foundation pit is transformed can be reduced, and the bearing capacity, the safety and the stability of the foundation pit are improved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of building engineering, concretely is a structure for existing building foundation pit reconstruction. BACKGROUND

[0002] With the high-speed development of urbanization, some existing buildings need to be planned to be reconstructed, the existing space is optimized, and the high quality and sustainable development of the city is ensured. The existing foundation pit wall is not enough to maintain the integrity, safety and stability of the updated building, so the existing wall structure needs to be reconstructed. The existing structure reconstruction is often more complex than the new construction project, and the bearing capacity and space requirements of the existing structure often do not meet the new project. In the existing foundation pit structure reconstruction, there are problems of large space occupation, high construction difficulty and long construction period. Therefore, a new type of foundation pit reconstruction structure is very needed to improve the bearing capacity and overall stability of the building, increase the space utilization, and reduce the construction difficulty. CONTENT OF THE UTILITY MODEL

[0003] In view of the existing problems of the above foundation pit reconstruction, the utility model provides a structure for existing building foundation pit reconstruction, which solves the problems of strict construction technology requirements, large space occupation and difficult construction quality guarantee.

[0004] The technical solution for realizing the purpose of the utility model is as follows:

[0005] A structure for existing building foundation pit reconstruction, comprising a newly-built bottom plate, a newly-built foundation pit wall, L-shaped steel bars arranged in the newly-built bottom plate, and hook-shaped steel bars; horizontal steel bars, vertical steel bars, first vertical steel bars, connectors, second vertical steel bars, force transmission steel bars, bent steel bars, transverse steel bars, equivalent connectors, and longitudinal steel bars arranged in the newly-built foundation pit wall; the first vertical steel bars comprise inner vertical steel bars and outer vertical steel bars;

[0006] The L-shaped steel bars are two rows, are lapped with the top steel bars of the existing bottom plate, and have upper ends extending out of the newly-built bottom plate;

[0007] The hook-shaped steel bars are horizontally arranged and are lapped with the top steel bars of the existing bottom plate;

[0008] The lower ends of the vertical steel bars are connected with the L-shaped steel bars, the upper ends of the vertical steel bars are connected with the lower ends of the second vertical steel bars through the connectors, the inner second vertical steel bars are connected with the lower ends of the inner vertical steel bars, the outer second vertical steel bars are connected with the lower ends of the inner vertical steel bars through the bent steel bars, and the upper ends of the inner vertical steel bars and the outer vertical steel bars are connected with the existing foundation pit wall through the equivalent connectors;

[0009] The transverse steel bars are located above the bent steel bars, one end of the transverse steel bars is tied with the inner vertical steel bars, and the other end of the transverse steel bars is tied with the outer vertical steel bars;

[0010] The horizontal steel bars are connected between two columns of vertical steel bars;

[0011] The force transmission steel bars are arranged between the existing foundation pit wall and the newly built foundation pit wall.

[0012] Compared with the prior art, the utility model has the following remarkable advantages:

[0013] (1) The new and old walls are connected through the force transmission steel bars, so that the overall structure is more uniform and stable in stress.

[0014] (2) The bent steel bars arranged at the section change of the wall can enhance the reliability of the structure.

[0015] (3) The steel bar members are connected through the connectors, so that the structure is simplified and the construction efficiency is improved.

[0016] (4) The new bottom plate is connected to the top steel bars of the existing bottom plate, so that the stress deformation of the new and old bottom plates is better coordinated. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a detail view of the foundation pit wall reconstruction.

[0018] Figure 2 is a new and old wall construction drawing.

[0019] Figure 3 is a new bottom plate connection.

[0020] Figure 4 is a force transmission steel bar construction drawing.

[0021] Figure 5 is a bent steel bar construction drawing.

[0022] PART OF THE DRAWING REFERENCE: 1, equivalent connector; 2, vertical steel bar; 3, first vertical steel bar; 4, bent steel bar; 5, existing bottom plate; 6, newly built bottom plate; 7, L-shaped steel bar; 8, existing foundation pit wall; 9, newly built foundation pit wall; 10, force transmission steel bar; 11, horizontal steel bar; 12, vertical steel bar; 13, longitudinal steel bar; 14, transverse steel bar; 15, connector; 16, top steel bar; 17, hooked steel bar DETAILED DESCRIPTION

[0023] The utility model will be further described below in combination with the drawings and specific embodiments.

[0024] The application discloses a structure for existing building foundation pit reconstruction.

[0025] Referring to Figure 1 and Figure 3The structure includes a newly-built bottom plate 6, a newly-built foundation pit wall 9, L-shaped steel bars 7, top steel bars 16, hooked steel bars 17, horizontal steel bars 11, vertical steel bars 2, first vertical steel bars 3, connectors 15, second vertical steel bars 12, force transmission steel bars 10, bent steel bars 4, transverse steel bars 14, equivalent connectors 1, and longitudinal steel bars 13. The first vertical steel bars 3 include inner vertical steel bars 3-1 and outer vertical steel bars 3-2. The L-shaped steel bars 7 and the hooked steel bars 17 are arranged in the newly-built bottom plate 6, and the horizontal steel bars 11, the vertical steel bars 2, the first vertical steel bars 3, the second vertical steel bars 12, the force transmission steel bars 10, the bent steel bars 4, the transverse steel bars 14, and the longitudinal steel bars 13 are arranged in the newly-built foundation pit wall.

[0026] With reference to Figure 1 and Figure 2 , the bottom of the existing foundation pit wall 8 is connected with the existing bottom plate 5 in an L shape, the existing bottom plate 5 of the building underground four floors is removed, and the top steel bars 16 inside the existing foundation pit wall 8 are protected during the removal process. The hooked steel bars 17 and the L-shaped steel bars 7 are arranged in the newly-built bottom plate 6, the upper ends of the two rows of L-shaped steel bars 7 extend out of the newly-built bottom plate 6 and are located in the newly-built foundation pit wall, and are overlapped with the top steel bars 16 of the existing bottom plate 5.

[0027] The hooked steel bars 17 of the newly-built bottom plate 6 are overlapped with the top steel bars 16 of the existing bottom plate 5, the newly-built bottom plate 6 is sunken by 1125 mm relative to the existing bottom plate 5, and the newly-built foundation pit wall 9 is arranged on the newly-built bottom plate 6. The new and old walls are reinforced and connected through the force transmission steel bars 10, a plurality of steel bars arranged at a certain interval are arranged inside the newly-built foundation pit wall 9, the upper ends of the vertical steel bars 3 with a diameter of 25 mm are connected with the existing foundation pit wall 8 through the equivalent connectors 1, and the vertical steel bars 3 are ensured to have a spacing of 150 mm along the length direction of the wall.

[0028] With reference to Figure 1 and Figure 3 , the L-shaped steel bars 7 are located on one side of the newly-built bottom plate 6 close to the existing foundation pit wall 8, and are welded with the top steel bars 16 to fix the position. The hooked steel bars 17 are arranged on the top of the newly-built bottom plate 6, the hooked steel bars 17 are bound to the middle and upper ends of the L-shaped steel bars 7, and the hooked parts are overlapped with the ends of the top steel bars 16 of the existing bottom plate 5. After the arrangement of the steel bars in the newly-built bottom plate 6 is completed, the pouring and curing of the newly-built bottom plate 6 are performed. Then, the steel bars in the newly-built foundation pit wall 9 are arranged.

[0029] With reference to Figure 1 , the vertical steel bars 2 are H25 type, the lower ends of the two rows of vertical steel bars 2 are bound to the upper ends of the L-shaped steel bars 7 of the newly-built bottom plate 6. The binding is performed at the overlapped parts by using 20-gauge iron wires, the binding points are firm and uniformly distributed, and the spacing between the binding points is not greater than 250 mm. The horizontal steel bars 11 are connected between the two rows of vertical steel bars 2, and are arranged at the same spacing as the vertical steel bars 2 along the length direction of the newly-built foundation pit wall 9.

[0030] The longitudinal steel bars 13 bind two parallel arranged vertical steel bars 2, and are symmetrically arranged in two rows up and down inside the vertical steel bars 2 along the wall width direction, and are arranged near one side of the existing foundation pit wall 8. Two rows of longitudinal steel bars 13 with a diameter of 25 mm are arranged on one side of the existing foundation pit wall 8, and the spacing along the wall length direction (perpendicular to the paper surface direction) is 150 mm; two rows of longitudinal steel bars 13 with a diameter of 32 mm are arranged on the other side (far away from the existing foundation pit wall 8), and the spacing along the wall length direction (perpendicular to the paper surface direction) is 150 mm. Figure 1 Figure 1

[0031] Referring to Figure 1 and Figure 4 , the lower end of the second vertical steel bar 12 is connected to the upper end of the vertical steel bar 2 through the connector 15, and the second vertical steel bar 12 on the side far away from the existing foundation pit wall 8 (i.e. the inner second vertical steel bar 12) is connected to the lower end of the inner vertical steel bar 3-1 in the new foundation pit wall 9 through the welded bent steel bar 4, and the upper end of the second vertical steel bar 12 on the side close to the existing foundation pit wall 8 (i.e. the outer second vertical steel bar 12) is bound to the lower end of the inner vertical steel bar 3-1; the lower end of the inner vertical steel bar 3-1 is welded to the upper end of the bent steel bar 4, and the middle part of the outer vertical steel bar 3-2 is welded to the middle part of the bent steel bar 4. The upper end of the inner vertical steel bar 3-1 and the upper end of the outer vertical steel bar 3-2 are connected to the existing foundation pit wall 8 through the equivalent connector 1.

[0032] The bent end of one end of the bent steel bar 4 is the width change position of the new foundation pit wall 9 at a height of 1336 mm from the bottom of the existing foundation pit wall 8; the bent end of the other end is the welding position of the inner vertical steel bar 3-1, and both are right-angled bent steel bars.

[0033] The transverse steel bar 14 is located above the bent steel bar 4, and one end is bound to the inner vertical steel bar 3-1 and the other end is bound to the outer vertical steel bar 3-2.

[0034] Referring to Figure 1 and Figure 5 , the force transmission steel bar 10 is arranged between the existing foundation pit wall 8 and the new foundation pit wall 9, and includes a top force transmission steel bar 10-1, a middle force transmission steel bar 10-2, and a middle-lower force transmission steel bar 10-3 arranged along the height direction of the existing foundation pit wall 8. The installation and construction steps of the force transmission steel bar 10 are as follows:

[0035] S1: The connection part of the existing foundation pit wall 8 is cleaned, so that the surface of the existing foundation pit wall 8 exposes a solid structure layer to ensure good contact between the force transmission steel bar 10 and the structure layer.

[0036] S2: Three rows of holes are formed on the existing foundation pit wall 8 along the wall height direction, and a plurality of holes are formed on the wall length direction at a certain spacing.

[0037] ​​S3: The force transmission steel bar 10 is passed through the hole to complete the connection of the new and old foundation pit wall, and the force transmission steel bar 10 is installed vertically embedded in the hole. The top force transmission steel bar 10-1 with a diameter of 13 mm and a length of 150 mm along the length direction of the wall is bound to the inner vertical steel bar 3-1 close to the existing foundation pit wall 8, and the end thereof is welded to the outer vertical steel bar 3-2 away from the existing foundation pit wall 8, and the outer vertical steel bar 3-2 is cut off in the middle of the new foundation pit wall 9; the middle force transmission steel bar 10-2 with a diameter of 13 mm and a length of 300 mm along the length direction of the wall is bound to the inner vertical steel bar 3-1, and the end thereof is welded to the horizontal steel bar 14 of the new foundation pit wall 9 after being bent downward; the middle and lower force transmission steel bar 10-3 with a diameter of 20 mm and a length of 150 mm along the length direction of the wall is bound to the inner vertical steel bar 3-1, and the end thereof is bent downward and located below the end of the outer vertical steel bar 3-2.

[0038] Referring to Figure 1 With Figure 2 , the upper ends of the inner vertical steel bar 3-1 and the outer vertical steel bar 3-2 in the new foundation pit wall 9 are connected to the existing foundation pit wall 8 through the equivalent connector 1. After the binding and welding of all the steel bars are completed, the formwork installation, concrete pouring, wall maintenance and formwork removal of the new foundation pit wall 9 are carried out in three steps:

[0039] S1: Formwork installation, the formwork is installed according to the design size and shape of the existing foundation pit wall 9, and the formwork is reinforced by using a suitable support system to ensure that the formwork will not deform or displace during the concrete pouring process.

[0040] S2: Concrete pouring, the strength grade of the concrete is C40. The existing foundation pit wall 9 is an irregular wall, and the vertical layered pouring method is adopted, and the layered thickness is controlled to be 50 mm.

[0041] S3: Wall maintenance and formwork removal, after the concrete pouring is completed, the maintenance time is not less than 7 days. When the concrete strength reaches the design requirement of the formwork removal strength, the formwork is removed. During the removal process, the new foundation pit wall 9 is protected.

Claims

1. A structure for the renovation of existing building foundation pits, characterized in that, This includes a newly constructed base slab and a newly constructed foundation pit wall; L-shaped steel bars and hooked steel bars arranged in the newly constructed base slab; horizontal steel bars, vertical steel bars, first vertical steel bars, connectors, second vertical steel bars, force-transmitting steel bars, bent-up steel bars, transverse steel bars, equivalent connectors, and longitudinal steel bars arranged in the newly constructed foundation pit wall; the first vertical steel bar includes inner vertical steel bars and outer vertical steel bars; The L-shaped steel bars are in two rows, overlapping with the top steel bars of the existing base slab, and extending out of the newly built base slab at the top. The hooked steel bars are arranged horizontally and overlap the top steel bars of the existing bottom slab; The lower end of the vertical steel bar is connected to the L-shaped steel bar, and the upper end is connected to the lower end of the second vertical steel bar through a connector. The inner second vertical steel bar is connected to the lower end of the inner vertical steel bar, and the outer second vertical steel bar is connected to the lower end of the inner vertical steel bar through a bent steel bar. The upper ends of the inner and outer vertical steel bars are connected to the existing foundation pit wall through equivalent connectors. The transverse reinforcing bars are located above the bent-up reinforcing bars, with one end tied to the inner vertical reinforcing bars and the other end tied to the outer vertical reinforcing bars. The horizontal reinforcing bars are connected between two rows of vertical reinforcing bars; The reinforcing bars are placed between the existing foundation pit wall and the newly built foundation pit wall.

2. The structure for the renovation of existing building foundation pits according to claim 1, characterized in that, The force-transmitting steel bars include top force-transmitting steel bars, middle force-transmitting steel bars, and lower middle force-transmitting steel bars arranged along the height direction of the existing foundation pit wall. The top force-transmitting steel bar connects the inner vertical steel bar and the outer vertical steel bar; The central force-transmitting steel bar is connected to the inner vertical steel bar, and the downwardly bent end is connected to the horizontal steel bar; The lower force-transmitting steel bar connects to the inner vertical steel bar, with its end bent downwards and located below the end of the outer vertical steel bar.

3. The structure for the renovation of existing building foundation pits according to claim 1, characterized in that, The newly constructed foundation pit wall is also equipped with longitudinal steel bars, and two rows of longitudinal steel bars are tied to the inner sides of the two rows of vertical steel bars respectively.

4. The structure for the renovation of existing building foundation pits according to claim 1, characterized in that, The transverse reinforcing bars are located above the bent-up reinforcing bars.

5. The structure for the renovation of existing building foundation pits according to claim 1, characterized in that, The newly built base plate is lower than the existing base plate.

6. The structure for the renovation of existing building foundation pits according to claim 1, characterized in that, The hooked steel bar is located at the top inside the newly built base slab.

7. The structure for the renovation of existing building foundation pits according to claim 1, characterized in that, The upright steel bars are of type H25, and the distance between the binding points of the upright steel bars and the L-shaped steel bars is no more than 250mm.

8. The structure for the renovation of existing building foundation pits according to claim 1, characterized in that, The diameter of the longitudinal steel bars on the side closer to the existing foundation pit wall is larger than the diameter of the longitudinal steel bars on the side farther away from the existing foundation pit wall.

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