Foundation pit supporting structure

Abstract

The utility model provides a foundation pit supporting structure which comprises top beams, a top cross brace and a plurality of micro piles, the micro piles are arranged on the two opposite sides of a foundation pit respectively, the top beams are arranged on the two opposite sides of the foundation pit, the top beams are arranged on the upper portions of the micro piles, the top cross brace penetrates through the middle of the foundation pit, and the micro piles are arranged on the top cross brace. The two ends of the top cross brace are connected with the top beams on the two sides of the foundation pit correspondingly, each top beam comprises a top beam reinforcement cage and concrete, the top beam reinforcement cages are arranged in the concrete, a first steel plate is embedded in the side, facing the foundation pit, of each top beam, the first steel plates are fixedly connected with the top beam reinforcement cages, and one side of each first steel plate is exposed on the surface of the corresponding top beam. The top cross brace is made of a steel pipe; the end part of the top cross brace is welded and fixed with the first steel plate; a jet grouting pile is arranged between every two adjacent micro piles, and the micro piles and the jet grouting piles form a water stop wall; the utility model not only is convenient to assemble and disassemble, but also has a water stop function.

Description

Technical Field

[0001] The utility model relates to the field of support construction, in particular to a foundation pit support structure. Background Art

[0002] For deep foundation pits, traditional Larsen steel sheet pile support has the problems of difficult construction organization and great impact on the lives of surrounding residents. Therefore, it is more advantageous to use micropile structure support. The micropile structure support includes a crown beam, a waist beam, a cross brace and multiple micro piles. The crown beam is connected to the upper part of multiple micro piles, the waist beam is connected to the middle part of multiple micro piles, and the two ends of the cross brace are respectively connected to the crown beam or waist beam on both sides of the foundation pit to play a supporting role to prevent the foundation pit from collapsing.

[0003] The existing cross braces are generally reinforced concrete support columns. The steel cage in the reinforced concrete support column is welded and fixed to the crown beam steel cage in the crown beam, and then concrete is poured. When the cross brace is subsequently dismantled, the concrete of the reinforced concrete support column must be broken first, and then the welded steel cage must be cut off. The dismantling work is large and time-consuming. In addition, in the existing micro-pile structure support, there is often a gap between two adjacent micro-piles, causing water outside the foundation pit to penetrate into the foundation pit, affecting the normal work of workers in the foundation pit. Utility Model Content

[0004] The utility model aims to provide a foundation pit supporting structure which is convenient to assemble and disassemble and has a water-stopping function.

[0005] In order to achieve the above-mentioned purpose, the utility model provides a foundation pit support structure, including a crown beam, a top cross brace and a plurality of micro piles, the plurality of micro piles are respectively arranged on opposite sides of the foundation pit, crown beams are arranged on opposite sides of the foundation pit, and the crown beams are arranged on the upper part of the micro piles, the top cross brace passes through the middle part of the foundation pit, and the two ends of the top cross brace are respectively connected to the crown beams on both sides of the foundation pit, the crown beam includes a crown beam steel cage and concrete, the crown beam steel cage is arranged in the concrete, the crown beam is pre-embedded with a first steel plate on the side facing the foundation pit, the first steel plate is fixedly connected to the crown beam steel cage, and one side of the first steel plate is exposed on the surface of the crown beam; the top cross brace is made of steel pipe, and the end of the top cross brace is welded and fixed to the first steel plate; a jet grouting pile is arranged between two adjacent micro piles, and the micro piles and the jet grouting piles form a water stop wall.

[0006] It can be seen from the above scheme that by using steel pipes to make the top cross brace, it can not only prevent the collapse of the foundation pit, but also facilitate installation and disassembly, which has the advantages of reducing the construction workload and saving construction time; by pre-embedding the first steel plate in the crown beam, it is ensured that the first steel plate will not be easily separated from the crown beam, which is beneficial to improving the structural stability of the top cross brace; by arranging rotary jet piles between two adjacent micro-piles, it is beneficial to form a sealed water-stop wall, which is beneficial to blocking the moisture on the periphery of the foundation pit from penetrating into the interior of the foundation pit, ensuring normal construction operations in the foundation pit.

[0007] A further solution is that the first steel plate is welded and fixed to the crown beam reinforcement cage, a supporting portion is provided on the bottom of the first steel plate by concrete, and the first steel plate is provided on the supporting portion.

[0008] A further solution is that the crown beam steel cage includes multiple longitudinal steel bars, multiple first stirrups and multiple reinforcing ribs, the longitudinal steel bars extend along the length direction of the crown beam, the first stirrups are sleeved on the outside of the multiple longitudinal steel bars, the two ends of the reinforcing ribs are respectively connected to the opposite sides of the first stirrups, and the first steel plate is directly welded and fixed to the multiple longitudinal steel bars.

[0009] A further solution is that the crown beam steel cage also includes connecting steel bars, which are L-shaped, one end of the connecting steel bars is fixedly connected to the first stirrup, and the other end of the connecting steel bars is fixedly connected to the first steel plate.

[0010] A further solution is that the distance between two adjacent micropiles is greater than the diameter of the micropiles and less than twice the diameter of the micropiles, and the jet-jet piles are engaged with the adjacent micropiles.

[0011] A further solution is that the diameter of the jet grouting pile is equal to the diameter of the micropile.

[0012] A further solution is that the foundation pit support structure also includes a middle cross brace and at least two waist beams; the micropile is provided with a bracket on the side facing the middle of the foundation pit, the waist beam is arranged on the bracket, and the two ends of the middle cross brace are respectively connected to the waist beams on both sides of the foundation pit.

[0013] A further solution is that the waist beam includes two I-beams and two second steel plates, the two second steel plates are arranged opposite to each other, the two I-beams are arranged up and down and arranged between the two second steel plates, and the I-beams are welded and fixed to the second steel plates.

[0014] A further solution is that the middle cross brace is made of a steel pipe, and the end of the middle cross brace is welded and fixed to the second steel plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural diagram of an embodiment of the utility model.

[0016] Figure 2 It is a top view of an embodiment of the utility model.

[0017] Figure 3 It is a schematic diagram of a water stop wall in an embodiment of the utility model.

[0018] Figure 4 It is a structural diagram of a micro pile reinforcement cage in an embodiment of the utility model.

[0019] Figure 5 It is a structural diagram of the first embodiment of the crown beam in the embodiment of the utility model.

[0020] Figure 6 It is a structural diagram of a second embodiment of a crown beam in an embodiment of the present utility model.

[0021] Figure 7 It is a structural diagram of a bracket and a waist beam in an embodiment of the utility model.

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments. DETAILED DESCRIPTION

[0023] See also Figures 1 to 4 The present embodiment provides a foundation pit support structure, comprising a crown beam 2, a top cross brace 3 and a plurality of micro piles 4.

[0024] A plurality of micropiles 4 are respectively arranged on opposite sides of the foundation pit 1, and a plurality of micropiles 4 are evenly spaced on each side of the foundation pit 1, and a jet grouting pile 5 is arranged between two adjacent micropiles 4, and the distance between the two adjacent micropiles 4 is greater than the diameter of the micropiles 4 and less than twice the diameter of the micropiles 4, and the jet grouting pile 5 is engaged with the adjacent micropiles 4, so that the jet grouting pile 5 can block the gap between the two adjacent micropiles 4, so that the micropiles 4 and the jet grouting pile 5 form a water stop wall to prevent the moisture outside the foundation pit 1 from penetrating into the foundation pit 1. During construction, the micropiles 4 are first applied, and then the jet grouting piles 5 are applied. In this embodiment, the diameter of the jet grouting pile 5 is equal to the diameter of the micropiles 4, so that the water stop wall has a uniform thickness.

[0025] A crown beam 2 is provided on both opposite sides of the foundation pit 1, and the crown beam 2 is fixedly connected to the upper part of the micropile 4. The length direction of the crown beam 2 extends along the arrangement direction of the plurality of micropiles 4, and the crown beam 2 is connected to the plurality of micropiles 4 at the same time. The micropiles 4 are cast with concrete, and a micropile steel cage 43 is provided in the micropile 4, and the upper steel bars of the micropile steel cage 43 extend into the crown beam 2. The micropile steel cage 43 includes a plurality of main bars 431, a plurality of second stirrups 432 and a winding bar 433. The plurality of main bars 431 are evenly arranged along a preset circle, and the second stirrups 432 are sleeved on the outside or inside of the plurality of main bars 431, and the second stirrups 432 are kept substantially perpendicular to the main bars 431, and then spot welded or tied. The winding bar 433 is spirally wound around the outside of the main bars 431 at a designed spacing, tied with thin iron wire and spot welded and fixed at a preset distance.

[0026] The crown beam 2 is cast with concrete, and the crown beam 2 includes a crown beam steel cage 22 and concrete. The crown beam steel cage 22 is arranged in the concrete, and the crown beam steel cage 22 is fixedly connected to the micropile steel cage 43. The crown beam 2 is pre-buried with a first steel plate 21 on the side facing the foundation pit 1. The number of the first steel plates 21 is set to multiple, and the multiple first steel plates 21 are arranged at intervals along the length direction of the crown beam 2. The first steel plate 21 is fixedly connected to the crown beam steel cage 22, and one side of the first steel plate 21 is exposed on the surface of the crown beam 2. The top cross brace 3 is arranged one-to-one with the first steel plate 21, and the top cross brace 3 is fixedly connected to the steel plate.

[0027] The top cross brace 3 passes through the middle of the foundation pit 1, and the two ends of the top cross brace 3 are respectively connected to the crown beams 2 on both sides of the foundation pit 1, playing a supporting role to prevent the foundation pit 1 from collapsing. The top cross brace 3 is made of a steel pipe, which can be a round pipe or a square pipe. The present embodiment is preferably a round pipe, and the end of the top cross brace 3 is welded and fixed to the first steel plate 21. The top cross brace 3 of this embodiment is made of a steel pipe. When installing, it is only necessary to weld and fix the steel pipe to the first steel plate 21. When disassembling, the steel pipe can be cut with a gas cutting gun to quickly disassemble the top cross brace 3. Compared with the steel cage concrete support column of the prior art, the process of pouring concrete and breaking concrete is omitted, which is conducive to saving construction time and reducing labor intensity.

[0028] exist Figure 5 In order to improve the structural stability of the first steel plate 21, the first steel plate 21 of this embodiment is welded and fixed to the crown beam reinforcement cage 22. Specifically, the crown beam reinforcement cage 22 includes a plurality of longitudinal reinforcements 221, a plurality of first stirrups 222 and a plurality of reinforcing ribs 223; the longitudinal reinforcements 221 extend along the length direction of the crown beam 2, and the first stirrups 222 are sleeved on the outside of the plurality of longitudinal reinforcements 221; the two ends of the reinforcing ribs 223 are respectively connected to the opposite sides of the first stirrups 222, preferably the two sides in the up and down direction. The first steel plate 21 is directly welded and fixed to the plurality of longitudinal reinforcements 221.

[0029] exist Figure 6 Furthermore, the crown beam steel cage 22 also includes a connecting steel bar 224, which is set to be L-shaped, one end of the connecting steel bar 224 is fixedly connected to the first hoop 222, and the other end of the connecting steel bar 224 is fixedly connected to the first steel plate 21 to further improve the structural strength of the first steel plate 21.

[0030] In order to improve the installation stability of the first steel plate 21 , a supporting portion 23 is provided at the bottom of the first steel plate 21 , and the first steel plate 21 is arranged on the supporting portion 23 , so that the supporting portion 23 plays a certain supporting role on the first steel plate 21 .

[0031] exist Figure 1 and Figure 7 In the embodiment, the foundation pit supporting structure further includes a middle cross brace 6 and at least two waist beams 42.

[0032] The micropile 4 is provided with a bracket 41 on one side facing the middle of the foundation pit 1. In the up-down direction, the bracket 41 is provided on the middle of the micropile 4, and each bracket 41 on the same side is substantially at the same height. A plurality of planting bars (not shown in the figure) are provided in the middle of the micropile 4. The planting bars protrude from the outer wall of the micropile 4 and are used for welding and fixing with the bracket 41, so as to fix and support the bracket 41.

[0033] The waist beam 42 is made of steel structure, and is arranged on a plurality of adjacent brackets 41. The waist beam 42 extends along the extension direction of the foundation pit 1. The middle cross brace 6 passes through the middle of the foundation pit 1, and the two ends of the middle cross brace 6 are respectively connected to the waist beam 42 on both sides of the foundation pit 1. Specifically:

[0034] The waist beam 42 includes two I-beams 421 and two second steel plates 422 . The two second steel plates 422 are arranged opposite to each other. The two I-beams 421 are arranged vertically between the two second steel plates 422 . The I-beams 421 and the second steel plates 422 are welded and fixed.

[0035] The middle cross brace 6 is made of a steel pipe, which may be a round pipe or a square pipe. In this embodiment, a round pipe is preferred. The end of the middle cross brace 6 is welded and fixed to the second steel plate 422 .

[0036] In summary, the utility model adopts steel pipes to make the top cross brace, which not only prevents the collapse of the foundation pit, but also facilitates installation and disassembly, and has the advantages of reducing the construction workload and saving construction time; by pre-embedding the first steel plate in the crown beam, it is ensured that the first steel plate will not be easily separated from the crown beam, which is beneficial to improving the structural stability of the top cross brace; by arranging rotary jet piles between two adjacent micro-piles, it is beneficial to form a sealed water-stop wall, which is beneficial to blocking the moisture on the periphery of the foundation pit from penetrating into the interior of the foundation pit, ensuring normal construction operations in the foundation pit.

[0037] Finally, it should be emphasized that the above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various changes and modifications. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A foundation pit support structure, comprising a crown beam, a top cross brace and a plurality of micro piles, wherein the plurality of micro piles are respectively arranged on opposite sides of a foundation pit, crown beams are arranged on opposite sides of the foundation pit, and the crown beams are arranged on the upper part of the micro piles, the top cross brace passes through the middle part of the foundation pit, and the two ends of the top cross brace are respectively connected to the crown beams on both sides of the foundation pit, characterized in that: The crown beam comprises a crown beam steel cage and concrete, wherein the crown beam steel cage is arranged in the concrete, and a first steel plate is pre-buried on a side of the crown beam facing the foundation pit, wherein the first steel plate is fixedly connected to the crown beam steel cage, and one side of the first steel plate is exposed on the surface of the crown beam; The top cross brace is made of a steel pipe, and the end of the top cross brace is welded and fixed to the first steel plate; A jet grouting pile is arranged between two adjacent micro piles, and a water stop wall is formed between the micro piles and the jet grouting piles.

2. The foundation pit support structure according to claim 1, characterized in that: The first steel plate is welded and fixed to the crown beam reinforcement cage, and the concrete is provided with a supporting portion at the bottom of the first steel plate, and the first steel plate is provided on the supporting portion.

3. The foundation pit supporting structure according to claim 2 is characterized in that: The crown beam steel cage includes a plurality of longitudinal steel bars, a plurality of first stirrups and a plurality of reinforcing bars. The longitudinal steel bars extend along the length direction of the crown beam. The first stirrups are sleeved on the outside of the plurality of longitudinal steel bars. The two ends of the reinforcing bars are respectively connected to the opposite sides of the first stirrups. The first steel plate is directly welded and fixed to the plurality of longitudinal steel bars.

4. The foundation pit supporting structure according to claim 3 is characterized in that: The crown beam steel cage also includes connecting steel bars, which are L-shaped, one end of which is fixedly connected to the first hoop, and the other end of which is fixedly connected to the first steel plate.

5. The foundation pit supporting structure according to claim 1, characterized in that: The distance between two adjacent micro-piles is greater than the diameter of the micro-pile and less than twice the diameter of the micro-pile, and the jet-jet pile is engaged with the adjacent micro-piles.

6. The foundation pit supporting structure according to claim 5, characterized in that: The diameter of the jet-jet pile is equal to the diameter of the micropile.

7. The foundation pit supporting structure according to claim 1, characterized in that: The foundation pit support structure also includes a middle cross brace and at least two waist beams; The micro pile is provided with a bracket on one side facing the middle of the foundation pit, the waist beam is arranged on the bracket, and the two ends of the middle cross brace are respectively connected to the waist beams on both sides of the foundation pit.

8. The foundation pit supporting structure according to claim 7, characterized in that: The waist beam includes two I-beams and two second steel plates. The two second steel plates are arranged opposite to each other. The two I-beams are arranged up and down and arranged between the two second steel plates. The I-beams are welded and fixed to the second steel plates.

9. The foundation pit supporting structure according to claim 8, characterized in that: The middle cross brace is made of a steel pipe, and the end of the middle cross brace is welded and fixed to the second steel plate.

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