Foundation pit structure for pipe jacking construction

Abstract

The utility model discloses a foundation pit structure for pipe jacking construction, which comprises a foundation pit main body, a plurality of soil nail steel bars are arranged on the side wall of the foundation pit main body, a steel bar mesh is hung at the exposed ends of the soil nail steel bars, concrete is sprayed on the surface of the steel bar mesh to form a concrete layer, and a plurality of inner hoop ring beams for supporting the concrete layer are arranged outside the concrete layer. The inner hoop ring beams and the concrete layer are integrally poured, and the inner hoop ring beams are sequentially arranged at intervals from top to bottom in the foundation pit body. According to the foundation pit structure for pipe jacking construction, natural slope making is not needed, the occupied space is small, and operation is easy.

Description

Technical Field

[0001] The utility model belongs to the field of pipe jacking construction, and in particular relates to a foundation pit structure for pipe jacking construction. Background Art

[0002] In the design of urban underground pipe networks, for process pipelines buried at a certain depth below the ground, large-scale excavation is not allowed according to the actual situation of the construction site, and the construction work surface must be minimized as much as possible. Generally, the jacking process is adopted (a construction technology used when the process pipeline crosses an existing road). Due to the limitation of the jacking length, it is necessary to excavate a temporary working foundation pit that is easy to operate within a certain jacking distance. Since the foundation pit is generally deep, when natural slope is adopted, a relatively large operating surface is required, the impact range is wide, and it is not easy to implement; if natural slope is not adopted, temporary support for the foundation pit is required. The commonly used methods are reinforced concrete retaining wall protection, or slope protection piles. When reinforced concrete retaining wall protection is adopted, the amount of steel bars and templates used is large, the cost is high, and the construction period is long; when slope protection piles are used, geological surveys must be conducted before implementation to provide pile foundation parameters, and the construction period is long and the cost is high. Utility Model Content

[0003] In view of the problems existing in the prior art, the utility model provides a foundation pit structure for pipe jacking construction, which does not require natural slope, occupies a small area and is easy to operate.

[0004] The technical solution adopted by the utility model is as follows:

[0005] A foundation pit structure for pipe jacking construction comprises a foundation pit body, wherein the side walls of the foundation pit body are provided with a plurality of soil nail steel bars at different heights, each of which is composed of a plurality of soil nail steel bars which are spaced apart along the circumference of the foundation pit body at substantially the same height, a steel mesh is hung on the exposed end of the soil nail steel bar, concrete is sprayed on the surface of the steel mesh to form a concrete layer, a plurality of inner hoop beams which play a supporting role for the concrete layer are provided outside the concrete layer, the inner hoop beams are integrally cast with the concrete layer, and the inner hoop beams are spaced apart in sequence from top to bottom along the inside of the foundation pit body.

[0006] Furthermore, a plurality of soil nail steel bars are distributed in a plum blossom shape, wherein the upper and lower adjacent rows of soil nail steel bars are staggered, and the horizontal spacing of the soil nail steel bars is preferably not greater than 0.8 m, preferably about 0.5 m, and the height spacing of the soil nail steel bars may be 0.3-0.8 m, preferably 0.4-0.6 m, and more preferably about 0.5 m. The soil nail steel bars are obliquely arranged in the soil, and the angle with the horizontal line may be, for example, 10-30 degrees, preferably 15-25 degrees, for example, about 20 degrees, and the distance between the first soil nail steel bar and the ground is 1-2 times the height spacing of the soil nail steel bars, preferably about 1.5 times.

[0007] Furthermore, the part of the soil nail reinforcement located in the soil body is provided with a plurality of support rings spaced apart along the length direction of the soil nail reinforcement, and each three support rings form a group. The plurality of support rings are connected to the soil nail reinforcement at equal intervals, for example, by welding. A plurality of (for example, three) support rods are extended circumferentially at intervals from the inner wall of the support ring to the soil nail reinforcement located in the support ring. The spacing distance of the support rings may be, for example, 1-2m, preferably about 1.5m. In the case of three support rods, the three support rods circumferentially surround the soil nail reinforcement, and the central angle between adjacent support rods may be, for example, 120 degrees. The support rods may be, for example, steel bars with a diameter of 8mm.

[0008] Furthermore, the support ring includes a limit frame which is attached to the inner wall of the anchor hole and used to limit the position of the soil nail reinforcement and a positioning rod connected to both ends of the limit frame. The positioning rod is welded to the soil nail reinforcement, and the limit frame is cylindrical.

[0009] Furthermore, a steel mesh is laid around the inner wall of the foundation pit body, the steel mesh is double-layered, each layer of the steel mesh includes transverse bars and vertical bars vertically connected to the transverse bars, the transverse bars and the vertical bars are arranged to form a grid, the transverse bars and the vertical bars are arranged at equal intervals, the transverse bars are welded or tied to the vertical bars, the transverse bar spacing can be, for example, 80-120mm, preferably about 100mm, the vertical bar spacing can be, for example, 80-120mm, preferably about 100mm.

[0010] Furthermore, the thickness of the concrete layer on the upper part of the foundation pit body can be, for example, 20-30 cm, preferably about 25 cm, the thickness of the concrete layer on the lower part of the foundation pit body can be, for example, 25-35 cm, preferably about 30 cm, the dividing line between the upper and lower parts of the foundation pit body can be, for example, 1 / 5-2 / 5 of the height of the foundation pit body, preferably about 2 / 5 of the height of the foundation pit body, and the material of the concrete layer can be, for example, C30.

[0011] Furthermore, reinforcing bars are usually arranged on the vertical bars near the soil nail reinforcement, and the reinforcing bars are parallel to the transverse bars. Preferably, there are two reinforcing bars, which are arranged on the upper and lower sides of the soil nail reinforcement and are welded to the soil nail reinforcement.

[0012] Furthermore, two vertical reinforcing bars are fixed on the soil nail steel bars between the two steel meshes. The reinforcing bars are arranged on the left and right sides of the soil nail steel bars, and the soil nail steel bars are connected to the midpoint or middle part of the reinforcing bars.

[0013] Furthermore, the reinforcement bars are connected with oblique bars, which are parallel to the soil nail steel bars. Each reinforcement bar is connected with an oblique bar, and the oblique bars on the two reinforcement bars are diagonally distributed. The entire length of the oblique bars is welded to the soil nail steel bars.

[0014] Furthermore, the inner hoop beam includes stirrups and stirrups arranged at intervals along the length direction of the stirrups. The thickness of the inner hoop beam is greater than the thickness of the concrete layer. The spacing of the inner hoop beams at the upper part of the foundation pit main body is greater than the spacing of the inner hoop beams at the lower part of the foundation pit main body. The spacing of the inner hoop beams at the upper part of the foundation pit main body can be, for example, 0.7-0.9m, preferably about 0.8m, and the spacing of the inner hoop beams at the lower part of the foundation pit main body can be, for example, 0.5-0.7m, preferably about 0.6m. The height of the inner hoop beams at the upper part of the foundation pit main body is greater than the height of the inner hoop beams at the lower part of the foundation pit main body. The height of the inner hoop beams at the upper part of the foundation pit main body can be, for example, 25-40cm, preferably about 30cm, and the height of the inner hoop beams at the lower part of the foundation pit main body can be, for example, 40-55cm, preferably about 45cm.

[0015] Furthermore, at each inner hoop ring beam (at the same elevation as the inner hoop ring beam), triangular supports are arranged at the four corners of the foundation pit body. The triangular supports are preferably made of I-beam steel, and the two ends of the I-beam steel are respectively welded to the steel plate embedded parts. The steel plate embedded parts include a back plate and anchor bars. The anchor bars are vertically fixed to one side of the back plate. The anchor bars are welded to the back plate and anchored into the inner hoop ring beam. The steel plate embedded parts are fixed to the inner hoop ring beam through corbels. The corbels include horizontal tensioning steel bars connected to the inner hoop ring beam and vertical structural steel bars anchored in the inner hoop ring beam. The horizontal tensioning steel bars and the vertical structural steel bars are alternately arranged. The back plate of the steel plate embedded parts is welded to the facade formed by the staggered horizontal tensioning steel bars and the vertical structural steel bars. The corbels adopt technical means well known to technical personnel in this field, which will not be repeated here. When the foundation pit depth is greater than or equal to 5 meters and the pit side length is greater than or equal to 4 meters, steel plate embedded parts and triangular supports are arranged on the inner side of the inner hoop ring beam below 5 meters to enhance the integrity and stability of the inner hoop ring beam at the same elevation.

[0016] Furthermore, a temporary vertical ladder is provided inside the main body of the foundation pit for construction workers to climb.

[0017] Furthermore, a retaining wall is provided on the bottom surface close to the edge of the foundation pit.

[0018] Beneficial effects of the utility model:

[0019] The utility model provides a foundation pit structure for pipe jacking construction, which uses soil nail steel bars to reinforce the soil layer to increase the integrity of the soil body. The steel mesh and the concrete layer directly support the reinforced soil body. The inner hoop beam supports the concrete layer. The inner hoop beam, soil nail steel bars, steel mesh and the concrete layer formed by spraying restrain the soil body, which saves space. The inner hoop beam and the soil nail steel bar spraying anchor are simple to construct, which saves investment and shortens the construction period. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The utility model is a template diagram of a foundation pit structure for pipe jacking construction.

[0021] Figure 2 for Figure 1 AA section view of the .

[0022] Figure 3 This is the elevation drawing of anchor spraying.

[0023] Figure 4 Schematic diagram of soil nail reinforcement structure.

[0024] Figure 5 for Figure 4 Enlarged view of point B in .

[0025] Figure 6 This is a large-scale drawing of the support ring.

[0026] Figure 7 Detail of the inner hoop beam.

[0027] Figure 8 Schematic diagram of the intersection of the corbel, embedded steel plate and triangular support.

[0028] Fig. 9 This is the front view of the steel plate embedded parts.

[0029] Fig.10 This is a side view of the steel plate embedded parts.

[0030] Reference numerals:

[0031] 1-main body of foundation pit, 2-soil nail steel bars, 3-steel mesh, 301-transverse bars, 302-vertical bars, 4-concrete layer, 5-inner hoop beam, 501-vertical bars, 502-hoops, 6-ground, 7-soil, 8-support ring, 801-limiting frame, 802-positioning rod, 9-anchor hole, 10-strengthening bars, 11-reinforcement bars, 12-oblique bars, 13-temporary straight ladder, 14-retaining wall, 15-weld, 16-triangular support, 17-embedded steel plates, 1701-back plate, 1702-anchor bars, 18-support rods, 19-corbel, 1901-horizontal tension steel bars, 1902-vertical structural steel bars. DETAILED DESCRIPTION

[0032] The utility model is further described below in conjunction with the accompanying drawings.

[0033] like Figure 1-7 As shown, a foundation pit structure for pipe jacking construction includes a foundation pit body 1, and the side walls of the foundation pit body 1 are provided with a plurality of soil nail steel bars 2 at different heights, each of which is composed of a plurality of soil nail steel bars 2 distributed at intervals along the circumference of the foundation pit body 1 at basically the same height, and a steel mesh 3 is hung on the exposed end of the soil nail steel bar 2, and concrete is sprayed on the surface of the steel mesh 3 to form a concrete layer 4, and a plurality of inner hoop beams 5 for supporting the concrete layer 4 are provided on the outside of the concrete layer 4, and the inner hoop beams 5 are integrally cast with the concrete layer 4, and the inner hoop beams 5 are sequentially spaced from top to bottom along the inside of the foundation pit body 1.

[0034] The multiple soil nail reinforcement bars 2 are distributed in a plum blossom shape, such as Figure 3 As shown, the plum blossom-shaped distribution is that the upper and lower adjacent rows of soil nail steel bars 2 are staggered, the horizontal spacing of the soil nail steel bars 2 is preferably not more than 0.8m, preferably about 0.5m, the height direction spacing of the soil nail steel bars 2 can be 0.3-0.8m, preferably 0.4-0.6m, more preferably about 0.5m, the soil nail steel bars 2 are inclinedly arranged in the soil body 7, and the angle with the horizontal line can be, for example, 10-30 degrees, preferably about 15-25 degrees, for example 20 degrees, and the distance between the first soil nail steel bar 2 and the ground 6 is 1-2 times the height direction spacing of the soil nail steel bars 2, preferably about 1.5 times.

[0035] The portion of the soil nail reinforcement 2 located in the soil body 7 is provided with a plurality of support rings 8 spaced apart along the length direction of the soil nail reinforcement 2, and each three support rings 8 form a group. The plurality of support rings are connected to the soil nail reinforcement 2 at equal intervals, for example, by welding. A plurality of (for example, three) support rods 18 are extended circumferentially at intervals from the inner wall of the support ring 8 to the soil nail reinforcement 2 located in the support ring. The spacing distance of the support ring 8 may be, for example, 1-2m, preferably about 1.5m. In the case of three support rods 18, the three support rods 18 circumferentially surround the soil nail reinforcement 2, and the central angle between adjacent support rods 18 may be, for example, 120 degrees. The support rods 18 may be, for example, steel bars with a diameter of 8mm.

[0036] The support ring 8 includes a limit frame 801 which is attached to the inner wall of the anchor hole 9 and is used to limit the position of the soil nail reinforcement 2, and a positioning rod 802 connected to both ends of the limit frame 801. The positioning rod 802 is welded to the soil nail reinforcement 2, and the limit frame 801 is cylindrical.

[0037] The steel mesh 3 is laid around the inner wall of the foundation pit body. The steel mesh 3 is double-layered. Each layer of the steel mesh 3 includes transverse reinforcement 301 and vertical reinforcement 302 vertically connected to the transverse reinforcement 301. The transverse reinforcement 301 and the vertical reinforcement 302 are arranged to form a grid. The transverse reinforcement 301 and the vertical reinforcement 302 are arranged at equal intervals. The transverse reinforcement 301 and the vertical reinforcement 302 are welded or tied together. The spacing between the transverse reinforcements 301 can be, for example, 80-120mm, preferably about 100mm, and the spacing between the vertical reinforcements 302 can be, for example, 80-120mm, preferably about 100mm.

[0038] The thickness of the concrete layer 4 on the upper part of the foundation pit main body 1 can be, for example, 20-30 cm, preferably about 25 cm, the thickness of the concrete layer 4 on the lower part of the foundation pit main body 1 can be, for example, 25-35 cm, preferably about 30 cm, the dividing line between the upper and lower parts of the foundation pit main body 1 can be, for example, 1 / 5-2 / 5 of the height of the foundation pit main body 1, preferably about 2 / 5 of the height of the foundation pit main body 1, and the material of the concrete layer 4 can be, for example, C30.

[0039] Reinforcing ribs 10 are usually arranged on the vertical ribs 302 near the soil nail reinforcement 2 . The reinforcing ribs 10 are parallel to the transverse ribs 301 . Preferably, there are two reinforcing ribs 10 , which are arranged on the upper and lower sides of the soil nail reinforcement 2 and are welded to the soil nail reinforcement 2 .

[0040] Two vertical reinforcing bars 11 are fixed on the soil nail steel bar 2 between the two steel meshes 3 . The reinforcing bars 11 are arranged on the left and right sides of the soil nail steel bar 2 . The soil nail steel bar 2 is connected to the midpoint or middle part of the reinforcing bars 11 .

[0041] The reinforcing bars 11 are connected with oblique bars 12, which are parallel to the soil nail steel bars 2. Each reinforcing bar 11 is connected with an oblique bar 12, and the oblique bars 12 on the two reinforcing bars 11 are diagonally distributed. The entire length of the oblique bars 12 is welded to the soil nail steel bars 2. The oblique bars 12 increase the end area of ​​the soil nail steel bars 2, increase the bond strength between the soil nail steel bars 2 and the concrete layer 4, and improve the bearing capacity of the soil nail steel bars 2.

[0042] The inner hoop beam 5 includes stirrups 501 and stirrups 502 arranged at intervals along the length direction of the stirrups 501. Preferably, the thickness of the inner hoop beam 5 is greater than the thickness of the concrete layer 4. The spacing between the inner hoop beams 5 at the upper part of the foundation pit main body 1 is greater than the spacing between the inner hoop beams 5 at the lower part of the foundation pit main body 1. The spacing between the inner hoop beams 5 at the upper part of the foundation pit main body 1 can be, for example, 0.7-0.9m, preferably about 0.8m, and the spacing between the inner hoop beams 5 at the lower part of the foundation pit main body 1 can be, for example, 0.5-0.7m, preferably about 0.6m. The height of the inner hoop beams 5 at the upper part of the foundation pit main body 1 is greater than the height of the inner hoop beams 5 at the lower part of the foundation pit main body 1. The height of the inner hoop beams 5 at the upper part of the foundation pit main body 1 can be, for example, 25-40cm, preferably about 30cm, and the height of the inner hoop beams 5 at the lower part of the foundation pit main body 1 can be, for example, 40-55cm, preferably about 45cm.

[0043] At each inner hoop beam 5 (at the same elevation as the inner hoop beam), triangular supports 16 are provided at the four corners of the foundation pit body 1. The triangular supports 16 are preferably made of I-beam steel, and the two ends of the I-beam steel are respectively welded to the steel plate embedded parts 17. Figure 8-10As shown, the steel plate embedded part 17 includes a back plate 1701 and an anchor bar 1702, the anchor bar 1702 is vertically fixed to one side of the back plate 1701, the anchor bar 1702 is welded to the back plate 1701 and anchored into the inner hoop ring beam 5, the steel plate embedded part 17 is fixed to the inner hoop ring beam 5 through a corbel 19, the corbel 19 includes a horizontal tensioning steel bar 1901 connected to the inner hoop ring beam 5 and a vertical structural steel bar 1902 anchored into the inner hoop ring beam 5, the horizontal tensioning steel bar 1901 and the vertical structural steel bar 1902 The steel bars 1902 are arranged in a staggered manner, and the back plate 1701 of the steel plate embedded part 17 is welded to the facade formed by the staggered horizontal tension steel bars 1901 and the vertical structural steel bars 1902. The corbel 19 adopts technical means well known to technical personnel in this field and will not be repeated here. When the foundation pit depth is greater than or equal to 5 meters and the pit side length is greater than or equal to 4 meters, the steel plate embedded part 17 and the triangular support 16 are arranged on the inner side of the inner hoop beam 5 below 5 meters to enhance the integrity and stability of the inner hoop beam at the same elevation.

[0044] A temporary vertical ladder 13 for construction workers to climb may be provided inside the foundation pit body 1 .

[0045] A water retaining wall 14 may be provided on the bottom surface near the edge of the foundation pit body 1 .

[0046] Weld seams 15 are formed between the diagonal reinforcement 12 and the soil nail reinforcement 2 and between the positioning rod 802 and the soil nail reinforcement 2.

[0047] The utility model provides a foundation pit structure for pipe jacking construction, wherein the force direction is: soil nail steel bars 2→steel mesh 3 and concrete layer 4→inner hoop beam 5.

[0048] The above describes the preferred embodiments of the present invention, however, the above description is not intended to be limiting. A person skilled in the art may make many changes or modifications to the present invention without departing from the spirit and scope of the present invention. The changes or modifications should be included in the scope of the appended claims.

Claims

1. A foundation pit structure for pipe jacking construction, characterized in that: The invention comprises a foundation pit body (1), wherein the side wall of the foundation pit body (1) is provided with a plurality of soil nail steel bars (2) at different heights, each of which is composed of a plurality of soil nail steel bars (2) distributed at intervals along the circumference of the foundation pit body (1) at substantially the same height, a steel mesh (3) is hung on the exposed end of the soil nail steel bar (2), concrete is sprayed on the surface of the steel mesh (3) to form a concrete layer (4), a plurality of inner hoop beams (5) supporting the concrete layer (4) are provided outside the concrete layer (4), the inner hoop beams (5) are integrally cast with the concrete layer (4), and the inner hoop beams (5) are sequentially arranged at intervals from top to bottom along the inside of the foundation pit body (1).

2. The foundation pit structure according to claim 1, characterized in that: The plurality of soil nail steel bars (2) are distributed in a plum blossom shape, and the soil nail steel bars (2) are arranged obliquely in the soil body (7).

3. The foundation pit structure according to claim 1 or 2, characterized in that: The portion of the soil nail reinforcement (2) located in the soil body (7) is provided with a plurality of support rings (8) arranged at intervals along the length direction of the soil nail reinforcement (2), with three support rings (8) forming a group, and the plurality of support rings (8) are connected to the soil nail reinforcement (2) at equal intervals.

4. The foundation pit structure according to claim 3, characterized in that: The support ring (8) comprises a limit frame (801) which is in contact with the inner wall of the anchor hole (9) and is used to limit the position of the soil nail reinforcement (2), and positioning rods (802) connected to both ends of the limit frame (801).

5. The foundation pit structure according to claim 1, characterized in that: The steel mesh (3) is double-layered, and each layer of the steel mesh (3) comprises transverse reinforcement (301) and vertical reinforcement (302) vertically connected to the transverse reinforcement (301), and the transverse reinforcements (301) and the vertical reinforcements (302) are arranged at equal intervals.

6. The foundation pit structure according to claim 1, characterized in that: The thickness of the concrete layer (4) at the upper part of the foundation pit body (1) is 20-30 cm, and the thickness of the concrete layer (4) at the lower part of the foundation pit body (1) is 25-35 cm.

7. The foundation pit structure according to claim 5, characterized in that: A reinforcing rib (10) is arranged on the vertical rib (302) close to the soil nail steel bar (2). The reinforcing rib (10) is parallel to the transverse rib (301). There are two reinforcing ribs (10) arranged on the upper side and the lower side of the soil nail steel bar (2).

8. The foundation pit structure according to claim 5, characterized in that: Two vertical reinforcing bars (11) are fixed on the soil nail steel bar (2) between the two steel meshes (3); the reinforcing bars (11) are arranged on the left and right sides of the soil nail steel bar (2); and the soil nail steel bar (2) is connected to the midpoint or middle part of the reinforcing bars (11).

9. The foundation pit structure according to claim 8, characterized in that: The reinforcing bars (11) are connected to oblique bars (12), the oblique bars (12) are parallel to the soil nail steel bars (2), each reinforcing bar (11) is connected to an oblique bar (12), and the oblique bars (12) on the two reinforcing bars (11) are distributed diagonally.

10. The foundation pit structure according to claim 1, characterized in that: The inner hoop beam (5) comprises a frame bar (501) and stirrups (502) arranged at intervals along the length direction of the frame bar (501); the thickness of the inner hoop beam (5) is greater than the thickness of the concrete layer (4); the spacing of the inner hoop beams (5) at the upper part of the foundation pit body (1) is greater than the spacing of the inner hoop beams (5) at the lower part of the foundation pit body (1); and the height of the inner hoop beams (5) at the upper part of the foundation pit body (1) is greater than the height of the inner hoop beams (5) at the lower part of the foundation pit body (1).

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