Deep and small foundation pit supporting structure without inner support and vertical support

Abstract

The invention relates to the technical field of supporting structures, and discloses a deep and small foundation pit supporting structure without an inner support and a vertical support, which comprises an annular mounting cavity, and an embedded part is arranged in the annular mounting cavity; a wing-shaped bracket is arranged on one side of the embedded part, annular combined type steel is arranged on the top of the wing-shaped bracket, two sets of hanging ribs are arranged on the annular combined type steel in a penetrating and inserting mode, an upper pulling and lower supporting structure is formed, use of a lower supporting column is avoided, and the construction space in a foundation pit is more open. The top end of the hanging rib is fixedly connected with the cast-in-situ bored pile or the underground diaphragm wall, and the bottom end of the hanging rib is connected with the end, away from the embedded part, of the wing-shaped bracket. The occupied area of the horizontal support of the foundation pit is reduced to be annular support, the annular inner space serves as an extremely smooth material conveying channel, meanwhile, the horizontal support structure is fixed through multiple sets of hinge supporting points, use of lower supporting columns is avoided, and the construction space in the foundation pit is more open.

Description

Technical Field

[0001] The present invention relates to the technical field of support structures, and more specifically, to a deep and small foundation pit support structure without internal support and vertical support. Background Art

[0002] Deep foundation pits are an essential part of modern architecture. With the development of modern construction engineering technology, the scale of construction projects has been continuously expanding, and a large number of deep foundation pits and super-large deep foundation pit projects have emerged. "Deep foundation pit support", which is crucial for construction safety, has become increasingly complex and important. The larger the deep foundation pit, the more corresponding support projects and the greater the construction difficulty. At this time, the choice of support method, that is, the problem of how to select the type, not only affects the construction difficulty and the control of construction costs, but also the support effect. Generally, slope cutting or various retaining structures are used in foundation pit engineering design. In the case of deep foundation pits, slope cutting requires more land, and corresponding retaining structures such as retaining piles and diaphragm walls are more widely used. As the depth of the foundation pit project increases, more horizontal supports are needed to increase the stiffness of the retaining structure. Generally, concrete supports or steel supports are used as supports, and vertical support columns are additionally provided vertically to support the horizontal supports.

[0003] However, traditional foundation pit support has the following defects or deficiencies:

[0004] 1) In some deep and small foundation pits, the addition of these horizontal supports leads to a sharp reduction in the construction space. Therefore, a new support structure form and method are needed to meet the construction requirements of deep and small foundation pits.

[0005] 2) The existing method of setting vertical columns to support horizontal supports divides the interior of the foundation pit into multiple small areas by the columns, making vehicle driving extremely inconvenient. Moreover, vehicle driving is likely to collide with the columns, affecting the safety of the foundation pit and making construction operations in the foundation pit difficult.

[0006] In response to the problems in the related art, no effective solution has been proposed yet. Summary of the Invention

[0007] In response to the problems in the related art, the present invention proposes a deep and small foundation pit support structure without internal support and vertical support to overcome the above-mentioned technical problems existing in the existing related art.

[0008] To this end, the specific technical solution adopted by the present invention is as follows:

[0009] According to one aspect of the present invention, a deep small foundation pit support structure without internal support and vertical support is provided, which includes an annular installation cavity opened in a bored cast-in-place pile or a diaphragm wall, and a buried part is arranged inside the annular installation cavity; a wing-shaped corbel is arranged on one side of the buried part, and an annular combined steel section is arranged on the top of the wing-shaped corbel. Two groups of hanging bars are inserted through the annular combined steel section to form an upper-pulling and lower-supporting structure, avoiding the use of lower support columns and making the construction space in the foundation pit more open; the top end of the hanging bar is fixedly connected to the bored cast-in-place pile or the diaphragm wall, and the bottom end of the hanging bar is connected to one end of the wing-shaped corbel away from the buried part.

[0010] Further, in order to better realize the installation and placement of the wing-shaped corbel, the buried part is a steel plate or a bolt. When the buried part is a steel plate, it is connected to the wing-shaped corbel by welding. When the buried part is a bolt, it is connected to the wing-shaped corbel by threading.

[0011] Further, in order to better support the annular combined steel section, the wing-shaped corbel includes a horizontal plate, and a vertical plate matching with it is arranged at the bottom of one end of the horizontal plate. One side of the vertical plate is in contact with the buried part, and several vertical support plates are arranged between one side of the vertical plate and the bottom of the horizontal plate.

[0012] Further, in order to achieve a better support effect, the annular combined steel section is composed of double H-shaped steel or double channel steel, and the heads and tails of several annular combined steel sections are connected into a closed-loop circular structure by flanges or welding. Truss ribs are inclinedly arranged in the cavity of the annular combined steel section, and the heads and tails of adjacent truss ribs are connected end to end to jointly form a broken-line structure. The truss ribs form a 45-degree angle with the tangent direction of the ring of the annular combined steel section. Through holes matching with the hanging bars are opened on the annular combined steel section, and the bottom end of the hanging bar is connected to one end of the wing-shaped corbel away from the buried part by bolts.

[0013] According to another aspect of the present invention, a deep small foundation pit support structure without internal support and vertical support is provided, which includes an annular installation cavity opened in a bored cast-in-place pile or a diaphragm wall, and a buried part is arranged inside the annular installation cavity; a wing-shaped corbel is arranged on one side of the buried part, and a concrete annular support is arranged on the top of the wing-shaped corbel. Two groups of hanging bars are inserted through the concrete annular support to form an upper-pulling and lower-supporting structure, avoiding the use of lower support columns and making the construction space in the foundation pit more open; the top end of the hanging bar is fixedly connected to the bored cast-in-place pile or the diaphragm wall, and the bottom end of the hanging bar is connected to one end of the wing-shaped corbel away from the buried part.

[0014] Further, in order to better realize the installation and placement of the wing-shaped corbel, the buried part is a steel plate or a bolt. When the buried part is a steel plate, it is connected to the wing-shaped corbel by welding. When the buried part is a bolt, it is connected to the wing-shaped corbel by threading.

[0015] Furthermore, in order to better achieve the supporting effect on the annular combined steel section, the wing-shaped corbel includes a horizontal plate. A vertical plate is arranged at the bottom of one end of the horizontal plate and is matched with it. One side of the vertical plate is in contact with the embedded part, and a number of vertical support plates are arranged between one side of the vertical plate and the bottom of the horizontal plate. A number of Z-shaped steel bars are arranged inside the concrete annular support. Through holes matched with the hanging bars are arranged on the concrete annular support, and the bottom end of the hanging bar is connected to the end of the wing-shaped corbel far from the embedded part by bolts.

[0016] The beneficial effects of the present invention are as follows: The present invention can not only reduce the occupied area of the foundation pit horizontal support to a circular annular support, effectively solving the problem that the horizontal support in a deep and small foundation pit occupies a large area, which is not conducive to earthwork excavation, transportation and the construction of foundation works below the ground, but also can use the annular internal space as an extremely smooth material transportation channel. At the same time, multiple groups of hinged supports are used to fix the horizontal support structure, avoiding the use of lower support columns, making the construction space in the foundation pit more open, and effectively solving the problem that the vertical support columns set in the deep foundation pit cut the space in the foundation pit, resulting in inconvenient lower construction and affecting construction safety and construction efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0018] Figure 1 is a schematic structural diagram of a deep and small foundation pit support structure without internal support and vertical support according to an embodiment of the present invention;

[0019] Figure 2 is an assembly schematic diagram of an annular combined steel section in a deep and small foundation pit support structure without internal support and vertical support according to an embodiment of the present invention;

[0020] Figure 3 is a partial structural schematic diagram of an annular combined steel section in a deep and small foundation pit support structure without internal support and vertical support according to an embodiment of the present invention;

[0021] Figure 4 is a cross-sectional view of an annular combined steel section in a deep and small foundation pit support structure without internal support and vertical support according to an embodiment of the present invention;

[0022] Figure 5 is a structural diagram of a deep and small foundation pit support structure without internal support and vertical support according to another embodiment of the present invention;

[0023] Figure 6 It is a sectional view of a concrete ring support in a deep and small foundation pit support structure without internal support and vertical support according to another embodiment of the present invention.

[0024] In the figure:

[0025] 1. Ring installation cavity; 2. Embedded part; 3. Wing-shaped corbel; 31. Horizontal plate; 32. Vertical plate; 33. Vertical support plate; 4. Ring combined steel section; 5. Hanging reinforcement; 6. Truss rib; 7. Concrete ring support; 8. Z-shaped steel bar. Detailed implementation manners

[0026] To further illustrate each embodiment, the present invention provides accompanying drawings, which are part of the disclosure of the present invention. They are mainly used to illustrate the embodiments and can be combined with the relevant descriptions in the specification to explain the operating principle of the embodiments. With reference to these contents, those of ordinary skill in the art should be able to understand other possible implementation manners and the advantages of the present invention. The components in the figures are not drawn to scale, and similar component symbols are usually used to represent similar components.

[0027] According to an embodiment of the present invention, a deep and small foundation pit support structure without internal support and vertical support is provided.

[0028] Now, the present invention will be further described in combination with the accompanying drawings and specific implementation manners. As Figures 1-4 shown, according to one aspect of the present invention, a deep and small foundation pit support structure without internal support and vertical support is provided, including a ring installation cavity 1 opened in a bored pile or diaphragm wall. An embedded part 2 is arranged inside the ring installation cavity 1; a wing-shaped corbel 3 is arranged on one side of the embedded part 2, and a ring combined steel section 4 is arranged on the top of the wing-shaped corbel 3. Moreover, the upper edge of the ring combined steel section 4 is close to the retaining structure, and the lower edge is close to the inner side of the foundation pit. In this embodiment, a combined steel section is selected as the ring support material for the foundation pit, such as double-ply H-shaped steel, double-ply channel steel, etc., which can be selected according to the actual situation and designed as a standard ring. The steel section is processed into an arc section and transported to the construction site. When the excavation reaches the position of the ring support, the steel sections are connected by flanges or welding to form a closed loop and installed at the designed position. Two groups of hanging reinforcements 5 are inserted through the ring combined steel section 4 to form an upper-pulling and lower-supporting structure, avoiding the use of lower support columns and making the construction space inside the foundation pit more open; the top end of the hanging reinforcement 5 is fixedly connected to the bored pile or diaphragm wall, and the bottom end of the hanging reinforcement 5 is connected to the end of the wing-shaped corbel 3 far from the embedded part 2.

[0029] Specifically, the wing-shaped corbel 3 and the hanging reinforcement 5 form a hinged fulcrum. In this embodiment, multiple groups of hinged fulcrums are provided. Each group of hinged fulcrums is designed with two folded steel bars with a diameter of more than φ28 as the hanging reinforcement plus a wing-shaped corbel. During the specific implementation, steel plates or bolts are pre-buried at the corresponding positions of the retaining pile or diaphragm wall and the wing-shaped corbel in advance. After excavation to this location, they are connected to the retaining pile or diaphragm wall by welding or bolts. At a position about 2h directly above the embedded part of the wing-shaped corbel, a section of concrete is chiseled open to expose the retaining pile or diaphragm wall, which is then welded to the hanging reinforcement. The other side of the hanging reinforcement passes through the combined steel section and is connected to the wing-shaped corbel by bolts, so that the support of the combined steel section only provides support for the lower wing-shaped corbel (the conventional vertical support method for the horizontal support of the foundation pit is that the lower corbel provides support, and the upper cable directly pulls the horizontal support structure. When designing, the cable is used as an insurance measure, and the lower corbel support is used as the main load-bearing component. However, in actual projects, this design leads to unclear force. The upper cable may participate in the force due to large tensile force or degradation of the load-bearing capacity of the lower corbel, or may receive an additional horizontal tensile force due to horizontal deformation). The force of such a hinged fulcrum is clear. According to the principle of deformation coordination, the upper tie rod and the lower support jointly bear the load. By setting stress monitors on the tie rod, the force conditions of the upper tie rod and the lower support can be deduced, and engineering warnings can be issued.

[0030] Among them, the embedded part 2 is a steel plate or a bolt. When the embedded part is a steel plate, it is connected to the wing-shaped corbel 3 by welding. When the embedded part is a bolt, it is connected to the wing-shaped corbel 3 by threading. The wing-shaped corbel 3 includes a horizontal plate 31. At the bottom of one end of the horizontal plate 31, a vertical plate 32 that matches it is provided. One side of the vertical plate 32 is in contact with the embedded part 2, and several vertical support plates 33 are provided between one side of the vertical plate 32 and the bottom of the horizontal plate 31. In specific applications, the wing-shaped corbel is welded by steel plates and includes a quadrilateral horizontal plate (i.e., the horizontal plate 31), and 2 triangular vertical support plates are provided below it. A quadrilateral attaching plate (i.e., the vertical plate 32) that closely adheres to the embedded part is provided on the side of the vertical support plate close to the retaining structure.

[0031] Truss ribs 6 are inclinedly arranged in the cavity of the annular combined steel section 4. In this embodiment, the truss ribs are steel plates with a certain thickness, which are respectively welded in the cavities I, II, and III of the combined steel section. Before welding, marking points are set at the welding points of the combined steel section. The marking points are set in a folded line form and form a 45° angle with the tangent direction of the combined steel section ring.

[0032] In specific applications, a circular horizontal support is designed at the center of the foundation pit. By using the characteristics of the circular structure, it bears the surrounding soil and water pressures transmitted by the retaining structure of the foundation pit. Utilizing the mechanical characteristics of the circular structure, circumferential stress is excited to resist external forces and prevent the deformation of the retaining piles. When the foundation pit size is not circular, horizontal support members in the form of peripheral trusses are set to fill the gap between the circular support and the retaining structure. For the circular support made of steel profiles, truss ribs and vertical ribs perpendicular to the circumferential tangent direction are set to prevent stress concentration under special working conditions. At the same time, the external forces are fully diffused to the surrounding of the stress points, making the structure safer. Anchor bolt holes are set at the intersection points of the truss ribs and between the vertical ribs, and reinforcement plates are set at the reserved positions of the anchor bolt holes to reinforce the stress concentration points. When the soil and water pressure is large, anchor bolts are added to reinforce the circular structure.

[0033] According to another aspect of the present invention, as Figures 5-6 shown, a deep and small foundation pit support structure without internal support and vertical support is provided, including a circular installation cavity 1 opened in a bored pile or diaphragm wall. An embedded part 2 is arranged inside the circular installation cavity 1; a wing-shaped corbel 3 is arranged on one side of the embedded part 2, and a concrete circular support 7 is arranged on the top of the wing-shaped corbel 3. Two groups of hanging bars 5 are inserted through the concrete circular support 7 to form an up-pulling and down-supporting structure, avoiding the use of lower support columns and making the construction space inside the foundation pit more spacious; the top ends of the hanging bars 5 are fixedly connected to the bored pile or diaphragm wall, and the bottom ends of the hanging bars 5 are connected to one end of the wing-shaped corbel 3 far from the embedded part 2.

[0034] Specifically, in this embodiment, a concrete support with a suitable size can be selected according to the actual situation and designed as a standard circle, and circumferential reinforcement is carried out according to the stress conditions. When carrying out reinforcement, broken-line reinforcement is added. Near-Z-shaped steel bars are designed, and the compressive and shear resistance of the circular concrete support is improved by bending at 45°, enhancing the ability of the structure to resist circumferential and inclined cracks and reducing the generation of inclined and circumferential cracks. At the same time, the addition of the broken-line steel bars enables the circular structure to more effectively excite circumferential stress in the structure when bearing external pressures, offsetting the external loads. Different from the case of the steel structure circular support, a duct is preset for the hanging bars before the concrete support is poured to facilitate its connection with the hinge points.

[0035] Among them, the embedded part 2 is a steel plate or a bolt. When the embedded part is a steel plate, it is connected to the wing-shaped bracket 3 by welding. When the embedded part is a bolt, it is connected to the wing-shaped bracket 3 by threading. The wing-shaped bracket 3 includes a horizontal plate 31. At the bottom of one end of the horizontal plate 31, a vertical plate 32 that matches it is provided. One side of the vertical plate 32 is in contact with the embedded part 2. Between one side of the vertical plate 32 and the bottom of the horizontal plate 31, a number of vertical support plates 33 are provided. Inside the concrete ring support 7, a number of Z-shaped steel bars 8 are provided. Through holes that match the hanging bars 5 are opened on the concrete ring support 7. The bottom end of the hanging bar 5 is connected to the end of the wing-shaped bracket 3 away from the embedded part 2 by bolts.

[0036] In specific applications, for the concrete ring support, in addition to the general circumferential reinforcement, folded-line reinforcement is added to reinforce the structure, improve the compressive and shear resistance of the ring structure, and reduce the generation of diagonal and circumferential cracks. At the same time, anchor bars are set and connected to the retaining structure through connecting sleeves. For the traditional vertical support, it is replaced by multiple groups of articulated supports. Steel plates or steel bars are embedded in the vertical support structure. Each group of articulated supports consists of two or more folded-line steel bars and a wing-shaped bracket, forming an upper-pulling and lower-supporting structure, and no longer occupying ground space.

[0037] To sum up, with the above technical solutions of the present invention, the present invention can not only reduce the occupied area of the foundation pit horizontal support to a circular support, effectively solving the problem that the horizontal support in a deep and small foundation pit occupies a large area, which is not conducive to earthwork excavation, transportation, and the construction of foundation works below the ground, but also can use the internal space of the ring as an extremely smooth material transportation channel. At the same time, multiple groups of articulated supports are used to fix the horizontal support structure, avoiding the use of lower support columns, making the construction space in the foundation pit more open, and effectively solving the problem that the vertical support columns set in the deep foundation pit cut the space in the foundation pit, resulting in inconvenient lower construction and affecting construction safety and construction efficiency.

[0038] In the present invention, unless otherwise clearly specified and limited, terms such as "installation", "setting", "connection", "fixation", "swivel connection" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. It can be the internal communication of two components or the interaction relationship between two components. Unless otherwise clearly limited, for those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0039] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A deep and small foundation pit support structure without internal support and vertical support, characterized in that: It comprises an annular installation cavity (1) opened on a bored pile or an underground continuous wall, wherein an embedded part (2) is arranged inside the annular installation cavity (1); A wing-shaped corbel (3) is provided on one side of the embedded part (2), an annular combined steel (4) is provided on the top of the wing-shaped corbel (3), and two groups of hanging bars (5) are inserted on the annular combined steel (4) to form an upper pull-down support structure, thereby avoiding the use of a lower support column and making the construction space in the foundation pit more spacious; The top end of the hanging bar (5) is fixedly connected to a bored pile or an underground continuous wall, and the bottom end of the hanging bar (5) is connected to an end of the wing-shaped corbel (3) away from the embedded part (2).

2. A deep and small foundation pit support structure without internal support and vertical support according to claim 1, characterized in that: The embedded part (2) is a steel plate or a bolt. When the embedded part is a steel plate, it is connected to the wing-shaped bracket (3) by welding. When the embedded part is a bolt, it is connected to the wing-shaped bracket (3) by threading.

3. A deep and small foundation pit support structure without internal support and vertical support according to claim 1, characterized in that: The wing-shaped corbel (3) comprises a horizontal plate (31), a vertical plate (32) matching with the horizontal plate (31) is arranged at the bottom of one end of the horizontal plate (31), one side of the vertical plate (32) is in contact with the embedded part (2), and a plurality of vertical support plates (33) are arranged between one side of the vertical plate (32) and the bottom of the horizontal plate (31).

4. A deep and small foundation pit support structure without internal support and vertical support according to claim 1, characterized in that: The annular combined steel sections (4) are composed of double H-shaped steel sections or double channel steel sections, and the ends of a plurality of the annular combined steel sections (4) are connected by flanges or welding to form a closed circular structure.

5. A deep and small foundation pit support structure without internal support and vertical support according to claim 1, characterized in that: Truss ribs (6) are obliquely arranged in the cavity of the annular combined steel section (4), and adjacent truss ribs (6) are connected end to end to form a broken line structure, and the truss ribs (6) and the circular tangent direction of the annular combined steel section (4) form an angle of 45 degrees.

6. A deep and small foundation pit support structure without internal support and vertical support according to claim 1, characterized in that: The annular combined steel section (4) is provided with a through hole matched with the hanging bar (5), and the bottom end of the hanging bar (5) is connected to the end of the wing-shaped corbel (3) away from the embedded part (2) by bolts.

7. A deep and small foundation pit support structure without internal support and vertical support, characterized in that: It comprises an annular installation cavity (1) opened on a bored pile or an underground continuous wall, wherein an embedded part (2) is arranged inside the annular installation cavity (1); A wing-shaped corbel (3) is provided on one side of the embedded part (2), a concrete annular support (7) is provided on the top of the wing-shaped corbel (3), and two groups of hanging bars (5) are inserted on the concrete annular support (7) to form an upper pull-down support structure, thereby avoiding the use of a lower support column and making the construction space in the foundation pit more spacious; The top end of the hanging bar (5) is fixedly connected to a bored pile or an underground continuous wall, and the bottom end of the hanging bar (5) is connected to an end of the wing-shaped corbel (3) away from the embedded part (2).

8. A deep and small foundation pit support structure without internal support and vertical support according to claim 7, characterized in that: The embedded part (2) is a steel plate or a bolt. When the embedded part is a steel plate, it is connected to the wing-shaped bracket (3) by welding. When the embedded part is a bolt, it is connected to the wing-shaped bracket (3) by threading.

9. A deep and small foundation pit support structure without internal support and vertical support according to claim 7, characterized in that: The wing-shaped corbel (3) comprises a horizontal plate (31), a vertical plate (32) matching with the horizontal plate (31) is arranged at the bottom of one end of the horizontal plate (31), one side of the vertical plate (32) is in contact with the embedded part (2), and a plurality of vertical support plates (33) are arranged between one side of the vertical plate (32) and the bottom of the horizontal plate (31).

10. A deep and small foundation pit support structure without internal support and vertical support according to claim 7, characterized in that: A plurality of Z-shaped steel bars (8) are arranged inside the concrete annular support (7), and a through hole matching the hanging bar (5) is opened on the concrete annular support (7), and the bottom end of the hanging bar (5) is connected to the end of the wing-shaped corbel (3) away from the embedded part (2) by bolts.

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