Foundation pit supporting method

Abstract

The embodiment of the invention provides a foundation pit supporting method, and relates to the technical field of foundation pit supporting. The foundation pit supporting method comprises the following steps that a supporting structure is arranged on the surface of a foundation pit; first waist beams are arranged on the horizontal plane and the vertical plane; a plurality of sleeves are obliquely arranged in the external corner of the foundation pit in a penetrating mode, and the sleeves are inclined from the horizontal plane and extend to the vertical plane in a penetrating mode; and a tensioning piece is arranged in the sleeve and used for connecting the supporting structure of the horizontal plane and the supporting structure of the vertical plane. The foundation pit supporting method provided by the invention can solve the problem that the supporting construction at the external corner of the foundation pit is difficult at present.

Description

Technical Field

[0001] The present invention relates to the technical field of foundation pit support, and in particular to a foundation pit support method. Background Art

[0002] Foundation pit support is a key component of rock engineering. Pit support typically utilizes methods such as slope reduction, cast-in-place piles (ground-anchored walls) + internal supports, or cast-in-place piles (ground-anchored walls) + anchor rods. However, when addressing the external corners of the foundation pit, reinforced concrete bracing or steel bracing is typically used. However, the spacing between steel braces cannot exceed 4 meters, making excavation difficult and slowing construction. If anchor rods are used, the close spacing of the anchor rods behind the support can easily lead to a cluster effect, reducing the anchor rod bearing capacity and failing to achieve the designed effect. This makes foundation pit support construction at external corners difficult. Summary of the Invention

[0003] The purpose of the present invention includes providing a foundation pit support method, which can improve the current problem of difficult support construction at the positive corners of the foundation pit.

[0004] The embodiments of the present invention can be implemented as follows: In a first aspect, the present invention provides a foundation pit support method, wherein the foundation pit has a foundation pit positive corner, and the foundation pit positive corner has a connected horizontal surface and a vertical surface, and the foundation pit support method comprises the following steps: Setting up supporting structures on the surface of foundation pit; A first waist beam is provided on the horizontal plane and the vertical plane; A plurality of casings are obliquely installed in the outer corner of the foundation pit, wherein the casings are inclined from the horizontal plane and extend through the vertical plane; A tensioning member is provided in the sleeve for connecting the support structure of the horizontal plane and the vertical plane.

[0005] In an optional embodiment, the step of obliquely installing a plurality of casing pipes in the external corner of the foundation pit includes: A plurality of through holes are provided at equal intervals on the first waist beam, the plurality of through holes located on the horizontal surface are arranged in one-to-one correspondence with the plurality of through holes located on the vertical surface, and the sleeve is obliquely passed through the two corresponding through holes.

[0006] In an optional embodiment, the casing is a 200*6 steel casing.

[0007] In an optional embodiment, the tensioning member includes a steel strand, and the step of arranging the tensioning member in the casing includes: A steel strand is passed through the casing, a pre-compression stress is applied to the steel strand, and one end of the steel strand located on the horizontal plane and one end located on the vertical plane are pulled and fixed.

[0008] In an optional embodiment, the step of providing a tensioning member in the sleeve includes: After the steel strand is passed through the casing, cement mortar is injected into the casing.

[0009] In an optional embodiment, the foundation pit supporting method further comprises the following steps: A second waist beam is provided on the side wall of the foundation pit, wherein the second waist beam is connected to the first waist beam; A plurality of anchor rods connected to the second waist beam are horizontally passed through the side wall of the foundation pit.

[0010] In an optional embodiment, the step of providing a second waist beam on the side wall of the foundation pit includes: A plate support is provided between the second waist beam and the first waist beam.

[0011] In an optional embodiment, the foundation pit supporting method further comprises the following steps: A third waist beam is arranged on the bottom wall of the foundation pit, and the third waist beam is connected to the first waist beam; A plurality of anchor rods connected to the third waist beam are vertically penetrated on the bottom wall of the foundation pit.

[0012] In an optional embodiment, the step of providing a third waist beam on the bottom wall of the foundation pit includes: A plate support is provided between the third waist beam and the first waist beam.

[0013] The beneficial effects of the foundation pit support method provided by the embodiment of the present invention include: by providing a support structure on the surface of the foundation pit, providing a first waist beam on the surface of the external corner of the foundation pit, obliquely inserting a casing into the external corner of the foundation pit, and providing a tensioning member within the casing, the horizontal and vertical surfaces of the first waist beam are connected, thereby connecting the support systems on both sides of the external corner of the foundation pit into a whole, strengthening the overall rigidity of the foundation pit and improving the support effect. At the same time, it avoids the pouring, replacement, and removal work of the traditional internal support method, and also avoids the group anchor effect accidents caused by the anchor cable method, achieving economic, safe, efficient and environmentally friendly results. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0015] Figure 1 A step diagram of the foundation pit supporting method provided in this embodiment; Figure 2This is a schematic structural diagram of the positive corner of the foundation pit in this embodiment; Figure 3 This is a schematic diagram of the internal structure of the sleeve provided in this embodiment.

[0016] Icons: 100-external corner of foundation pit; 110-horizontal surface; 120-vertical surface; 200-support structure; 300-first waist beam; 400-casing; 500-tensioning piece; 600-second waist beam; 700-third waist beam; 800-anchor rod; 900-plate support. DETAILED DESCRIPTION

[0017] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0018] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are intended to fall within the scope of protection of the present invention.

[0019] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0020] In the description of the present invention, it should be noted that if the terms "upper", "lower", "inside", "outside", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the accompanying drawings, or is the orientation or position relationship in which the product of the invention is usually placed when in use. It is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be understood as a limitation on the present invention.

[0021] In addition, the terms "first", "second", etc., if used, are merely used to distinguish and describe, and should not be understood as indicating or implying relative importance.

[0022] It should be noted that, in the absence of conflict, the features in the embodiments of the present invention may be combined with each other.

[0023] Foundation pit support is a temporary or permanent support measure implemented during excavation to prevent soil collapse, ensure construction safety, and maintain stability in the surrounding environment. It is a key component of geotechnical engineering. Traditional foundation pit support typically employs methods such as slope reduction, cast-in-place piles (ground-anchored walls) + internal supports, or cast-in-place piles (ground-anchored walls) + anchor bolts. However, these support methods are only suitable for straight sections or inner corners of the foundation pit. External corners, a weak link in the support structure, are prone to deformation and even collapse due to stress concentration and complex cavitation effects, requiring special measures to strengthen the support.

[0024] Currently, reinforced concrete or steel bracing is commonly used to support the external corners of foundation pits. However, construction specifications require that the spacing between steel braces cannot exceed 4 meters, which makes excavation inconvenient and slows the construction cycle. Furthermore, the initial construction of reinforced concrete bracing and the subsequent replacement and removal of braces increase both the construction period and project costs. If anchor rods are used, the close spacing of the anchor rods behind the support can easily lead to a cluster effect, reducing the anchor rod bearing capacity and failing to achieve the designed effect. This makes foundation pit support construction at external corners difficult.

[0025] In view of the current difficulty in supporting the outer corners of foundation pits, the present invention provides a foundation pit support method. The following describes in detail the detailed steps, implementation principles, and technical effects of the foundation pit support method provided by the present invention through examples and in conjunction with the accompanying drawings.

[0026] Please refer to Figure 1-Figure 3 The present invention provides a foundation pit support method, which is applied to the support at the positive corner 100 of the foundation pit, so as to improve the overall stability of the foundation pit, reduce the deformation and collapse at the positive corner 100 of the foundation pit, and improve the current construction difficulty problem when supporting the positive corner 100 of the foundation pit.

[0027] Please refer to Figure 2 The foundation pit provided by the present invention has a foundation pit positive corner 100, which is located in the corner area of ​​the foundation pit. The foundation pit positive corner 100 has a connected horizontal surface 110 and a vertical surface 120, wherein the vertical surface 120 is vertically connected to the bottom wall of the foundation pit, and the horizontal surface 110 is horizontally connected to the side wall of the foundation pit.

[0028] For details, please refer to Figure 1 The foundation pit supporting method provided by the present invention comprises the following steps: Step S100: Setting a support structure 200 on the surface of the foundation pit.

[0029] The support structure 200 may be a concrete layer or a wall structure provided on the surface of the foundation pit, and is used to form a preliminary support on the surface of the foundation pit.

[0030] Step S200 : Disposing a first waist beam 300 on the horizontal surface 110 and the vertical surface 120 .

[0031] In this embodiment, please refer to Figure 1 and Figure 2 The first side beam 300 is installed on the surface of the external corner 100 of the foundation pit. The first side beam 300 on the horizontal surface 110 is fixedly connected to the first side beam 300 on the vertical surface 120 by welding or other means. The first side beam 300 installed on the surface of the external corner 100 of the foundation pit provides initial support and reinforcement for the external corner 100 of the foundation pit. It also serves as a mounting platform for other reinforcement devices. The first side beam 300 can be constructed using various structural forms, including steel plates, steel frames, and steel beams.

[0032] In step S300 , a plurality of casings 400 are obliquely installed in the external corner 100 of the foundation pit. The plurality of casings 400 are obliquely installed from the horizontal surface 110 and extend through the vertical surface 120 .

[0033] In this embodiment, please refer to Figure 2 , the casing 400 is passed through the outer corner 100 of the foundation pit along a 45° direction, that is, the casing 400 is passed through at an angle of 45° from the horizontal plane 110 toward the vertical plane 120, and the casing 400 passes through the horizontal plane 110 and the vertical plane 120. The multiple casings 400 are arranged at equal intervals. It can be understood that due to the different positions of the multiple casings 400, the lengths of the multiple casings 400 are also different. Furthermore, the spacing between adjacent casings 400 is selected according to the construction design requirements. In this embodiment, the casing 400 adopts a 200*6 steel casing 400. In other embodiments, the specific structural dimensions and material of the casing 400 can be adaptively selected according to the construction design requirements.

[0034] Specifically, step S300 may include the following steps: Step S310: A plurality of through holes are opened on the first waist beam 300 at equal intervals, and the through holes on the horizontal surface 110 correspond to the through holes on the vertical surface 120 in a one-to-one manner, and the sleeve 400 is obliquely inserted into the two corresponding through holes.

[0035] By opening a through hole on the first waist beam 300, the sleeve 400 is passed through the through hole on the horizontal surface 110 and the through hole on the vertical surface 120. It is easy to pass the sleeve 400 into the foundation pit positive corner 100, so as to facilitate construction.

[0036] Step S400 : a tensioning member 500 is arranged in the sleeve 400 to connect the horizontal surface 110 and the vertical surface 120 .

[0037] After the casing 400 is installed in the external corner of the foundation pit 100, the casing 400 connects the horizontal surface 110 with the vertical surface 120. At this time, a tensioning member 500 is installed in the casing 400. The tensioning member 500 connects the horizontal surface 110 and the vertical surface 120. Thus, the tensioning member 500 connects the support structure 200 of the horizontal surface 110 and the vertical surface 120 into a whole, thereby improving the overall structural rigidity of the external corner of the foundation pit 100. In this embodiment, the tensioning member 500 includes a steel strand, wherein the specific size and type of the steel strand is adaptively selected according to the construction requirements.

[0038] Wherein, step S400 further includes the following steps: Step S410 : inserting a steel strand into the casing 400 , applying pre-compression stress on the steel strand, and pulling and fixing one end of the steel strand located on the horizontal plane 110 and the other end located on the vertical plane 120 .

[0039] Please refer to Figure 3 Because the casing 400 is hollow, multiple spaces are formed within the foundation pit external corner 100 for the steel strands to pass through. The steel strands are passed through the casing 400, and pre-compressive stress is applied to the steel strands. The ends of the steel strands are then pulled and fixed to the horizontal surface 110 and the vertical surface 120, respectively. As a result, the steel strands are in a taut state and constantly apply tension to the horizontal and vertical surfaces 110, 120, thereby connecting the support structures 200 on the horizontal and vertical surfaces 110, 120, forming a whole, and improving the structural rigidity of the foundation pit external corner 100. Specifically, the ends of the steel strands are connected to the first waist beam 300 through the cooperation of anchors and pedestals.

[0040] Wherein, step S400 further includes the following steps: Step S420: After the steel strands are inserted into the casing 400 , cement mortar is injected into the casing 400 .

[0041] Please refer to Figure 3 After the steel strand is passed through and tightened in the casing 400, cement mortar is injected into the casing 400. After the cement mortar solidifies, multiple concrete columns are formed in the external corner 100 of the foundation pit. While protecting the steel strand, the concrete columns of the casing 400 can also reinforce the external corner 100 of the foundation pit.

[0042] Furthermore, in order to improve the integrity between the foundation pit external corner 100 and the foundation pit body, thereby improving the support effect of the foundation pit external corner 100. In other embodiments, the foundation pit support method further includes the following steps: S500: Install a second waist beam 600 on the sidewall of the foundation pit. The second waist beam 600 is fixedly connected to the first waist beam 300. Multiple anchor rods 800 are horizontally inserted through the sidewall of the foundation pit and connected to the second waist beam 600. Install a third waist beam 700 on the bottom wall of the foundation pit and connected to the first waist beam 300. Multiple anchor rods 800 are vertically inserted through the bottom wall of the foundation pit and connected to the third waist beam 700.

[0043] A second side beam 600 is installed on the sidewall of the foundation pit, and a third side beam 700 is installed on the bottom wall of the foundation pit. Both the second and third side beams 600 and 700 are fixedly connected to the first side beam 300. This integrally connects the support structure 200 at the outer corner 100 of the foundation pit with the support structure 200 of the foundation pit itself. Furthermore, to enhance the support effectiveness of the foundation pit, anchor rods 800 are installed on both the second and third side beams 600 and 700, securing them to the foundation pit and increasing its structural rigidity.

[0044] Furthermore, step S500 further includes the following steps: Step S510: Install a plate support 900 between the second waist beam 600 and the first waist beam 300. Install a plate support 900 between the third waist beam 700 and the first waist beam 300. Installing the plate support 900 at the connection between the first waist beam 300 and the second waist beam 600, and at the connection between the first waist beam 300 and the third waist beam 700, improves the support effect between the first waist beam 300 and the second waist beam 600, and between the first waist beam 300 and the third waist beam 700, thereby improving the overall support effect of the foundation pit.

[0045] In summary, the implementation principle of the foundation pit support method provided by the present invention is as follows: by setting a support structure 200 on the surface of the foundation pit, setting a first waist beam 300 on the surface of the foundation pit positive corner 100, obliquely passing a casing 400 in the foundation pit positive corner 100, and setting a tensioning member 500 in the casing 400, the horizontal surface 110 and the vertical surface 120 of the first waist beam 300 are connected, thereby connecting the support systems on both sides of the foundation pit positive corner 100 into a whole, strengthening the overall rigidity of the foundation pit, and improving the support effect. At the same time, it avoids the pouring, replacement and removal work of the traditional internal support method, and also avoids the group anchor effect accident caused by the anchor cable method, achieving the effect of economy, safety, efficiency and environmental protection.

[0046] The above description is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with this technical field within the technical scope disclosed in the present invention should be covered by the scope of protection of the present invention.

Claims

1. A foundation pit support method, wherein the foundation pit has a foundation pit positive angle, and the foundation pit positive angle has a connected horizontal surface and a vertical surface, characterized in that: The foundation pit supporting method comprises the following steps: Setting up supporting structures on the surface of foundation pit; A first waist beam is provided on the horizontal plane and the vertical plane; A plurality of casings are obliquely installed in the outer corner of the foundation pit, wherein the casings are inclined from the horizontal plane and extend through the vertical plane; A tensioning member is provided in the sleeve for connecting the support structure of the horizontal plane and the vertical plane.

2. The foundation pit supporting method according to claim 1, characterized in that: The step of obliquely inserting a plurality of casing pipes in the positive corner of the foundation pit comprises: A plurality of through holes are provided at equal intervals on the first waist beam, the plurality of through holes located on the horizontal surface are arranged in one-to-one correspondence with the plurality of through holes located on the vertical surface, and the sleeve is obliquely passed through the two corresponding through holes.

3. The foundation pit supporting method according to claim 1, characterized in that: The casing is a 200*6 steel casing.

4. The foundation pit supporting method according to claim 1, characterized in that: The tensioning member includes a steel strand, and the step of arranging the tensioning member in the casing includes: A steel strand is passed through the casing, a pre-compression stress is applied to the steel strand, and one end of the steel strand located on the horizontal plane and one end located on the vertical plane are pulled and fixed.

5. The foundation pit supporting method according to claim 4, characterized in that: The step of arranging a tensioning member in the sleeve comprises: After the steel strand is passed through the casing, cement mortar is injected into the casing.

6. The foundation pit supporting method according to claim 1, characterized in that: The foundation pit supporting method further comprises the following steps: A second waist beam is provided on the side wall of the foundation pit, wherein the second waist beam is connected to the first waist beam; A plurality of anchor rods connected to the second waist beam are horizontally passed through the side wall of the foundation pit.

7. The foundation pit supporting method according to claim 6, characterized in that: The step of providing a second waist beam on the side wall of the foundation pit comprises: A plate support is provided between the second waist beam and the first waist beam.

8. The foundation pit supporting method according to claim 1, characterized in that: The foundation pit supporting method further comprises the following steps: A third waist beam is provided on the bottom wall of the foundation pit, wherein the third waist beam is connected to the first waist beam; A plurality of anchor rods connected to the third waist beam are vertically penetrated on the bottom wall of the foundation pit.

9. The foundation pit supporting method according to claim 8, characterized in that: The step of arranging the third waist beam on the bottom wall of the foundation pit comprises: A plate support is provided between the third waist beam and the first waist beam.

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