Foundation pit support system

Abstract

The utility model discloses a kind of foundation pit support systems, comprising: inner support, extend along horizontal direction;Column, for supporting inner support, column includes two steel sheet piles, support plate connected between two steel sheet piles, and rib plate respectively arranged between two steel sheet piles and support plate, support plate is supported in inner support, and two steel sheet piles are respectively located at the two sides of inner support along width direction. The vertical force that inner support transmits in succession can be transmitted to support plate, steel sheet pile, then again transmitted to the soil layer below foundation pit bottom, form stable support system. Column realizes the support of inner support by means of support plate, and restricts inner support to move along width direction by means of two steel sheet piles, can realize that inner support is stably supported, and inner support and support plate do not need to be welded, avoid the problem of inclination caused by welding precision not high of column and inner support.

Description

Technical Field

[0001] This utility model relates to the field of foundation pit protection technology, and in particular to a foundation pit support system. Background Technology

[0002] In the fields of building construction and underground engineering, the foundation pit support system is the core structure that ensures the safety of foundation pit excavation and construction and prevents damage to the surrounding environment. Among them, the coordinated work of the internal bracing and the columns is the key to maintaining the stability of the support system. The internal bracing mainly bears the soil pressure and water pressure transmitted by the retaining wall, restricting the horizontal displacement of the retaining wall and the settlement of the top of the foundation pit. The columns, as the vertical load-bearing and restraining components of the internal bracing, need to transfer the weight of the internal bracing itself and the vertical component force transmitted from the retaining wall to the foundation or existing foundation, while providing vertical restraint for the internal bracing to prevent it from vertical displacement, tilting or buckling.

[0003] Currently, the steel support columns used in foundation pit support systems are mostly single steel pipes. However, the steel pipes need to be fixed to the internal supports by welding. This can easily lead to the steel pipes tilting due to inaccurate welding positions, affecting the support effect and resulting in low reliability. Utility Model Content

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a foundation pit support system with high reliability.

[0005] A foundation pit support system according to some embodiments of the present invention includes: an inner support extending in a horizontal direction; and a column for supporting the inner support. The column includes two sheet piles spaced apart along the width direction of the inner support, a support plate connected between the two sheet piles, and ribs respectively disposed between the two sheet piles and the support plate. The support plate supports the inner support, and the two sheet piles are respectively located on both sides of the inner support along the width direction.

[0006] The foundation pit support system according to the embodiments of this utility model has at least the following beneficial effects: In this foundation pit support system, the vertical force transmitted from the internal support can be sequentially transferred to the support plate, sheet piles, and then to the soil layer below the bottom of the foundation pit, forming a stable support system. The columns support the internal support with the aid of the support plate, and the two sheet piles restrict the movement of the internal support along its width, ensuring stable support. Furthermore, the elimination of the need to weld the internal support to the support plate avoids tilting problems caused by inaccurate welding between the columns and the internal support, thus providing a more reliable support effect.

[0007] According to some embodiments of the present invention, the column further includes a gusset plate assembly, which is connected to the two sheet piles.

[0008] According to some embodiments of the present invention, there are multiple gusset plate assemblies, which are arranged at vertical intervals, and each gusset plate assembly is connected to two sheet piles.

[0009] According to some embodiments of the present invention, the gusset plate assembly includes two gusset plates, and both ends of the two gusset plates are respectively connected to the two sheet piles.

[0010] According to some embodiments of the present invention, each sheet pile is provided with a steel section on the side away from the support plate, and the steel section extends vertically.

[0011] According to some embodiments of the present invention, each sheet pile is connected to a web and a flange connected to the side of the web away from the support plate. The web and the flange are arranged vertically and extend vertically. The width direction of the web is parallel to the spacing direction of the two sheet piles.

[0012] According to some embodiments of this utility model, the column also includes two mixing piles or jet grouting piles respectively connected to the lower ends of the two sheet piles.

[0013] According to some embodiments of the present invention, each sheet pile is further provided with a pile tip at its bottom.

[0014] According to some embodiments of this utility model, a reinforcing plate is provided between the steel sheet pile and the pile tip.

[0015] According to some embodiments of the present invention, the reinforcing plate includes a first reinforcing plate and a second reinforcing plate, the first reinforcing plate and the second reinforcing plate being located on both sides of the steel sheet pile, respectively.

[0016] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein: Figure 1 This is a side view of the foundation pit support system according to Embodiment 1 of this utility model; Figure 2 This is a top view of the column according to Embodiment 1 of this utility model; Figure 3 This is a side view of the foundation pit support system according to Embodiment 2 of this utility model; Figure 4 This is a top view of the column according to Embodiment 2 of this utility model; Figure 5This is a side view of the foundation pit support system according to Embodiment 3 of this utility model; Figure 6 This is a top view of the column according to Embodiment 3 of this utility model; Figure 7 This is a side view of the foundation pit support system of Embodiment 4 of this utility model; Figure 8 This is a top view of the column in Embodiment 4 of this utility model; Figure 9 This is a schematic diagram of the steel sheet pile and mixing pile of Embodiment 5 of this utility model; Figure 10 for Figure 9 Top view of the figure shown; Figure 11 This is a schematic diagram of the steel sheet pile, pile tip, and mixing pile of Embodiment Six of this utility model; Figure 12 for Figure 11 Top view of the figure shown; Figure 13 This is a schematic diagram of the steel sheet pile and pile tip in Embodiment 7 of this utility model; Figure 14 for Figure 13 The top view of the figure shown.

[0018] Icon labels: 100. Internal support; 200, Column; 210, Sheet pile; 211, First reinforcing plate; 212, Second reinforcing plate; 220, Support plate; 230, Rib plate; 240, Connecting plate assembly; 241, Connecting plate; 250, Section steel; 260, Web plate; 270, Flange; 280, Mixing pile; 290, Pile tip. Detailed Implementation

[0019] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0020] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "transverse," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, features defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0021] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0022] Example 1 like Figure 1 , Figure 2 As shown, the foundation pit support system provided in Embodiment 1 of this utility model includes an internal support 100 and a column 200.

[0023] For example, the internal support 100 can be a steel structure. The foundation pit support system also includes two retaining walls, which are spaced apart horizontally. The internal support 100 extends horizontally and its two ends are connected to the two retaining walls respectively. The internal support 100 can withstand the soil pressure and water pressure on the retaining walls, preventing the retaining walls from tilting or cracking due to excessive force on one side. At the same time, the internal support 100 limits the horizontal displacement of the retaining walls and the settlement of the top of the foundation pit through its own rigidity, which can prevent damage to surrounding roads, pipelines, and buildings due to foundation pit deformation.

[0024] The column 200 is used to support the inner support 100. The core function of the column 200 is vertical load bearing. The inner support 100 has its own weight and will also bear part of the vertical force transmitted from the enclosure wall. The column 200 can transfer these vertical loads to the foundation or existing foundation below. In addition, the inner support 100 is mostly a horizontally stressed structure with relatively weak vertical stiffness. The column 200 can provide vertical restraint to prevent the inner support 100 from vertical displacement, tilting or buckling, and ensure the overall stability of the support system.

[0025] It should be noted that the number of columns 200 can be one or more. When there are multiple columns 200, the multiple columns 200 are spaced apart along the length of the inner support 100 and jointly support the inner support 100. In this way, the risk of vertical displacement, tilting or buckling of the inner support 100 can be further reduced.

[0026] The column 200 includes two sheet piles 210 spaced apart along the width direction of the inner support 100, and a support plate 220 connected between the two sheet piles 210. The support plate 220 supports the inner support 100, and the two sheet piles 210 are located on both sides of the inner support 100 along the width direction.

[0027] Specifically, both sheet piles 210 extend vertically, and the spacing between the two sheet piles 210 is horizontal and perpendicular to the length direction of the inner support 100. The two sheet piles 210 are respectively arranged on both sides of the inner support 100 along the width direction. The support plate 220 is connected to the two sheet piles 210 and is used to support the inner support 100. When the support plate 220 supports the inner support 100, the two sheet piles 210 can restrict the movement of the inner support 100 along the width direction.

[0028] Understandably, the vertical force transmitted from the inner support 100 can be sequentially transferred to the support plate 220, the sheet piles 210, and then to the soil layer below the bottom of the foundation pit, forming a stable support system. The column 200 supports the inner support 100 with the help of the support plate 220, and restricts the movement of the inner support 100 along the width direction with the help of the two sheet piles 210. This ensures that the inner support 100 is stably supported, and there is no need to weld the inner support 100 to the support plate 220, avoiding the tilting problem caused by low welding precision between the column and the inner support 100, thus providing a more reliable support effect for the inner support 100.

[0029] Furthermore, the support plate 220 is made of steel plate, and it can be fixed to the sheet pile 210 by welding, specifically by full welding. This creates a highly rigid connection node, maximizing the transfer of vertical and horizontal loads and significantly improving the overall stability and deformation resistance of the support system. Specifically, full welding ensures complete fusion of the connection surfaces between the support plate 220 and the sheet pile 210. Whether the horizontal force of the inner support 100 is transferred to the column 200, or the vertical load borne by the column 200 is transferred to the foundation, the load is uniformly transmitted through the entire weld surface, preventing localized stress concentration that could lead to node failure. Additionally, the full weld has the largest weld length and area, providing stronger shear and pull-out bearing capacity, preventing tearing, detachment, or other failures of the node under lateral or vertical forces.

[0030] Furthermore, the column 200 also includes a rib plate 230. Ribs plate 230 are provided between the two sheet piles 210 and the support plate 220. The rib plate 230 can improve the connection strength between the sheet piles 210 and the support plate 220.

[0031] Specifically, a rib plate 230 is welded at each connection node between the sheet pile 210 and the support plate 220.

[0032] It should be noted that when steel sheet piles are used extensively as retaining walls throughout the project, steel sheet piles are also used for the columns. This will improve the utilization efficiency of steel sheet pile construction machinery, eliminating the need to find other machinery to construct the steel pipes for the columns. This results in a relatively smaller construction site footprint and is more conducive to other construction operations.

[0033] Example 2 like Figure 3 , Figure 4 As shown, the foundation pit support system provided in Embodiment 2 of this utility model differs from Embodiment 1 in that the column 200 further includes a connecting plate assembly 240. The connecting plate assembly 240 connects two sheet piles 210, which can reduce the risk of lateral instability of the sheet piles 210 under stress. Specifically, the cross-sectional stiffness of a single sheet pile 210 is limited, and it is prone to bending deformation under soil pressure and water pressure. In addition to the support plate 220, the connecting plate assembly 240 can also "bind" two parallel sheet piles 210 to form a larger cross-section assembly, thereby increasing the bending stiffness and effectively reducing the bending and torsional deformation of the sheet piles 210 under lateral force, thus preventing the support system from failing due to insufficient stiffness. In addition, during construction or use, the sheet piles 210 may tilt, misalign, or even overturn due to uneven geology or excessive local stress. The gusseted plate assembly 240 can limit the relative displacement of the two sheet piles 210, prevent a single sheet pile 210 from becoming vertically unstable, and resist the torsional tendency of the sheet piles 210, ensuring that the support system remains straight and stable vertically.

[0034] Furthermore, there are multiple gusset assemblies 240, which are arranged vertically at intervals, and each gusset assembly 240 is connected to two sheet piles 210. In this way, the risk of the sheet piles 210 losing lateral stability under stress can be further reduced.

[0035] Specifically, the gusset assembly 240 includes two gusset plates 241, both ends of which are connected to two sheet piles 210 respectively, and the spacing direction of the two gusset plates 241 is parallel to the length direction of the inner support 100.

[0036] Implementation Three like Figure 5 , Figure 6As shown, the foundation pit support system provided in Embodiment 3 of this utility model differs from Embodiment 2 in that each sheet pile 210 has a steel section 250 on the side away from the support plate 220, and the steel section 250 extends vertically. Specifically, the column 200 includes two steel sections 250, which are respectively connected to two sheet piles 210, and each steel section 250 is located on the side of the sheet pile 210 connected to it away from the support plate 220. The steel section 250 and the sheet pile 210 can be fixed by welding. The installation of the steel section 250 can further reduce the risk of lateral instability of the sheet pile 210 under stress.

[0037] Understandably, the sheet pile 210 itself has limited stiffness, and when facing deep soft soil or deep foundation pits, it is prone to bending or shear failure due to excessive lateral earth pressure. Vertically extending steel sections 250 (such as I-beams) can be welded to the sheet pile 210 to form a composite section of "sheet pile + steel section". The moment of inertia and section modulus of this composite section are significantly increased, which can directly improve the bending and shear resistance of the sheet pile 210, enabling it to adapt to higher lateral loads.

[0038] Example 4 like Figure 7 , Figure 8 As shown, the foundation pit support system provided in Embodiment 4 of this utility model differs from Embodiment 2 in that each sheet pile 210 is connected to a web plate 260 on the side away from the support plate 220, and a flange 270 is connected to the side of the web plate 260 away from the support plate 220. The web plate 260 and flange 270 are vertically arranged and extend vertically. The width direction of the web plate 260 is parallel to the spacing direction of the two sheet piles 210. Specifically, the web plate 260 and flange 270 are set together, and the column 200 has two sets of web plates 260 and flanges 270. The two sets of web plates 260 and flanges 270 are respectively connected to two sheet piles 210. Each set of web plates 260 and flanges 270 is located on the side of the sheet pile 210 connected to it away from the support plate 220. For each set of web 260 and flange 270, web 260 is connected to the side of sheet pile 210 away from support plate 220, and flange 270 is connected to the side of web 260 away from support plate 220.

[0039] Example 5 like Figure 9 , Figure 10 As shown, the foundation pit support system provided in Embodiment 5 of this utility model differs from Embodiments 1 to 4 in that the column 200 further includes two mixing piles 280 or jet grouting piles respectively connected to the lower ends of the two sheet piles 210.

[0040] Understandably, when the soil friction below the bottom of the foundation pit is low, mixing piles 280 or jet grouting piles can be added below the bottom of the foundation pit, with sheet piles 210 inserted into them. This arrangement can improve the vertical bearing capacity of the sheet piles 210 and prevent the sheet piles 210 from sinking.

[0041] Example 6 like Figure 11 , Figure 12 As shown, the foundation pit support system provided in Embodiment Six of this utility model differs from Embodiment Five in that each sheet pile 210 is further provided with a pile tip 290 at its bottom. It can be understood that the pile tip 290 can improve the vertical end bearing capacity.

[0042] Furthermore, a reinforcing plate is installed between the sheet pile 210 and the pile tip 290. This reinforcing plate strengthens the connection between the sheet pile 210 and the pile tip 290, disperses stress concentration, and prevents damage to the connection joint during pile driving and under load. Specifically, the pile tip 290 bears a huge vertical impact force during pile driving and needs to transmit the lateral soil pressure and pull-out force of the sheet pile 210 during use. If the sheet pile 210 and the pile tip 290 are directly connected, the load will be concentrated at the weld seam or contact edge, easily leading to weld cracking and deformation at the bottom of the pile. The reinforcing plate (steel plate), by covering a larger connection area, can evenly transmit the impact force and soil reaction force of the pile tip 290 to the sheet pile 210, significantly reducing local stress peaks and preventing joint failure due to stress concentration. Furthermore, the sheet pile 210 and the pile tip 290 may differ in material and cross-sectional shape, resulting in a weaker joint stiffness. During pile driving or when the foundation pit is under stress, relative displacement may easily occur between the two (such as offset of the pile tip 290 or bending of the bottom of the sheet pile 210), affecting the guidance and pull-out resistance of the pile tip 290. The reinforcing plate, firmly bonded to both through welding, can improve the overall stiffness of the joint, limit the relative deformation of the sheet pile 210 and the pile tip 290, and ensure that they always work together and do not deviate from the design stress state.

[0043] Furthermore, the reinforcing plate includes a first reinforcing plate 211 and a second reinforcing plate 212, which are located on both sides of the sheet pile 210. This further strengthens the connection between the sheet pile 210 and the pile tip 290.

[0044] Example 7 like Figure 13 , Figure 14 As shown, the foundation pit support system provided in Embodiment 7 of this utility model differs from Embodiment 5 in that it does not include a mixing pile 280 or a jet grouting pile at the lower end of the sheet pile 210. Additionally, it incorporates the web 260 and flange 270 provided in Embodiment 4.

[0045] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0046] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A foundation pit support system, characterized in that, include: Internal support, extending horizontally; A column is used to support the inner support. The column includes two sheet piles spaced apart along the width direction of the inner support, a support plate connecting the two sheet piles, and ribs respectively disposed between the two sheet piles and the support plate. The support plate supports the inner support, and the two sheet piles are respectively located on both sides of the inner support along the width direction.

2. The foundation pit support system according to claim 1, characterized in that, The column also includes a gusset plate assembly, which is connected to the two sheet piles.

3. The foundation pit support system according to claim 2, characterized in that, The number of the gusset plate assemblies is multiple, and the multiple gusset plate assemblies are arranged at vertical intervals, and each gusset plate assembly is connected to two sheet piles.

4. The foundation pit support system according to claim 2, characterized in that, The gusset assembly includes two gusset plates, each with its two ends connected to one of the two sheet piles.

5. The foundation pit support system according to claim 1, characterized in that, Each sheet pile has a steel section on the side away from the support plate, the steel section extending vertically.

6. The foundation pit support system according to claim 1, characterized in that, Each sheet pile has a web and a flange connected to the side of the web away from the support plate. The web and the flange are arranged vertically and extend vertically. The width direction of the web is parallel to the spacing direction of the two sheet piles.

7. The foundation pit support system according to claim 1, characterized in that, The column also includes two mixing piles or jet grouting piles respectively connected to the lower ends of the two sheet piles.

8. The foundation pit support system according to claim 1, characterized in that, Each of the sheet piles is also provided with a pile tip at its bottom.

9. The foundation pit support system according to claim 8, characterized in that, A reinforcing plate is provided between the sheet pile and the pile tip.

10. The foundation pit support system according to claim 9, characterized in that, The reinforcing plate includes a first reinforcing plate and a second reinforcing plate, which are located on both sides of the sheet pile, respectively.

Images