Foundation pit supporting method for urban bridge

Abstract

The invention discloses a foundation pit supporting method for urban bridges, which comprises the following steps: step 1, excavation of a foundation pit: a plurality of groups of steel sheet piles are inserted into the foundation pit through a pile driver to support the side wall of the foundation pit, and meanwhile, the plurality of groups of steel sheet piles form a frame structure; secondly, after the foundation pit is excavated to a set depth, a plurality of sets of reinforcing assemblies are installed on the inner side wall of each side edge of the frame structure in a one-to-one correspondence mode; and thirdly, supporting mechanisms are installed, specifically, the multiple sets of supporting mechanisms are installed between every two adjacent sets of reinforcing assemblies, and the lengths of the supporting mechanisms are adjusted according to the size of the frame structure and locked. According to the foundation pit supporting method for the urban bridge, a plurality of force transmission paths can be formed while the steel sheet piles are supported through the supporting mechanisms, stress dispersion is facilitated, and the stability and safety of the whole device are improved.

Description

Technical Field

[0001] This invention relates to the field of foundation pit support technology, and in particular to a foundation pit support method for urban bridges. Background Art

[0002] Bridge deep foundation pits refer to excavations ≥5 meters deep for bridge foundations (such as abutments and piers). Support structures are required to ensure pit wall stability and the safety of the surrounding environment. These pits face challenges such as complex geology, high water pressure, and the need to protect adjacent buildings. The support system must possess both structural strength and deformation control capabilities, making it a critical risk control aspect of bridge construction. Due to the significant depth of the foundation pits for river-crossing bridges, the loose surface and middle soil layers, and the risk of water accumulation during rainy season construction, the excavation and support of the foundation pits are the most challenging aspects of the project. In existing technologies, sheet piles are generally used to form continuous sheet pile retaining walls for soil and water retention. However, due to the relatively small lateral stiffness of sheet piles, they deform significantly. After the backfill in the foundation pit is cleared, the top of the sheet pile retaining wall is subjected to lateral pressure, but lacks effective support, making it easy for the top to tilt. The conventional approach is to install support mechanisms to support the sidewalls of the sheet pile retaining wall. However, these support mechanisms can only be modified by cutting and cannot be flexibly adjusted according to the site conditions, resulting in the inability to reuse the support mechanisms and increasing construction costs.

[0003] Therefore, in the process of supporting the foundation pit during bridge construction, how to ensure that the support mechanism can be flexibly adjusted and reused while providing support for the steel sheet pile retaining wall is a technical problem that urgently needs to be solved in the existing technology. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a method for foundation pit support for urban bridges, which provides support for steel sheet pile retaining walls by setting up a support mechanism. At the same time, the support mechanism can be flexibly adjusted according to the on-site construction conditions, thereby improving the applicability of the device.

[0005] The present invention provides a method for foundation pit support for urban bridges, comprising the following steps:

[0006] Step 1: Excavation of the foundation pit. Several sets of steel sheet piles are inserted into the foundation pit using a pile driver to support the side walls of the foundation pit. At the same time, the several sets of steel sheet piles form a frame structure.

[0007] Step 2: After the foundation pit excavation reaches the set depth, install several sets of reinforcing components one by one on the inner side wall of each side of the frame structure.

[0008] Step 3: Install the support mechanism. Install several sets of support mechanisms between two adjacent sets of reinforcing components. Adjust the length of the support mechanism according to the size of the frame structure and lock it.

[0009] Furthermore, in step two, each set of reinforcing components includes a reinforcing rod and several connecting frames. The reinforcing rod is detachably fixed to the inner wall of the frame structure through several connecting frames, and the several connecting frames are detachably and evenly distributed on the inner wall of the frame structure.

[0010] Furthermore, the connecting frame has a U-shaped structure, which is fastened to the reinforcing rod and detachably fixed to the inner wall of the frame structure.

[0011] Furthermore, in step three, the two ends of each set of support mechanisms are respectively hinged to the set positions of two adjacent reinforcing rods and together with the two adjacent reinforcing rods to form the reinforcing structure;

[0012] The reinforcing structure is triangular.

[0013] Furthermore, the support mechanism includes a sliding frame, sliding rod I, and sliding rod II. One end of sliding rod I is hinged to one of the reinforcing rods, and the other end of sliding rod I slides through the sliding frame. One end of sliding rod II is hinged to another reinforcing rod adjacent to one of the reinforcing rods, and the other end of sliding rod II slides through the sliding frame. The positions of sliding rod I and sliding rod II relative to the sliding frame are adjustable and can be locked, so that the length of the support mechanism is adjustable and can be locked.

[0014] Furthermore, the support mechanism also includes a threaded column, two fixed plates, and two threaded sleeves. The two fixed plates are disposed inside the sliding frame. The threaded column passes through the two fixed plates in sequence and is rotatably connected to the two fixed plates. The two threaded sleeves are respectively sleeved on both ends of the threaded column and threadedly engaged with the threaded column. The sliding rod I and sliding rod II are respectively fixedly connected to the outer periphery of the two threaded sleeves, and the two ends of the threaded column extend into the two sliding rods I and sliding rod II respectively.

[0015] Furthermore, the support mechanism also includes two limiting blocks, which are fixedly disposed at both ends of the threaded column.

[0016] Furthermore, the support mechanism also includes a movable plate and two sliders disposed within the sliding frame. The two sliders are disposed one-to-one on the outer periphery of sliding rod I and sliding rod II. The movable plate is disposed on the top and bottom of the sliders and forms an I-shaped structure with the sliders. The I-shaped structure is slidably disposed on the sliding frame.

[0017] Furthermore, the support mechanism also includes an operating part, which is fixedly sleeved on the threaded column and located between two fixed plates.

[0018] Furthermore, the reinforcing rod is provided with a hinge portion, and the sliding rod I and sliding rod II are respectively provided with hinge seats that cooperate with the hinge portion.

[0019] The beneficial effects of this invention are as follows: The foundation pit support method for urban bridges of this invention forms a frame structure by setting up several sets of steel sheet piles, and the frame structure supports the foundation pit, which can prevent the foundation pit from collapsing. At the same time, by setting a support mechanism between the two adjacent sides of the frame structure, the steel sheet piles can be supported and multiple force transmission paths can be formed. When the steel sheet piles are subjected to lateral pressure, the force can be dispersed by the support mechanism, thereby improving the stability of the device. Moreover, the length of the support mechanism is adjustable and can be locked, so it can be adjusted according to the actual conditions of the construction site, improving the flexibility of the device. Attached Figure Description

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0021] Figure 1 This is a schematic diagram of the structure of the steel sheet pile and the support mechanism of the present invention when they are used together;

[0022] Figure 2 This is a structural diagram showing the fit between the reinforcing rod and the connecting frame.

[0023] Figure 3 A sectional view of the supporting mechanism;

[0024] Figure label:

[0025] 1. Sheet pile; 2. Connecting frame; 3. Reinforcing rod; 4. Support mechanism; 41. Sliding frame; 42. Fixing plate; 43. Threaded column; 44. Operating part; 45. Threaded sleeve; 46. Sliding rod I; 47. Sliding block; 48. Movable plate; 49. Sliding rod II; 5. Hinge part; 6. Hinge seat. Detailed Implementation

[0026] Figure 1 This is a schematic diagram of the structure of the steel sheet pile and the support mechanism of the present invention. Figure 2 This is a structural diagram showing the fit between the reinforcing rod and the connecting frame. Figure 3 A sectional view of the supporting mechanism, such as Figure 1-3 As shown: This embodiment of the method for foundation pit support for urban bridges includes the following steps:

[0027] Step 1: Excavation of the foundation pit. Several sets of sheet piles 1 are inserted into the foundation pit using a pile driver to support the side walls of the pit. Simultaneously, these sets of sheet piles 1 form a frame structure. Once the foundation pit has been excavated to a certain depth, several sets of sheet piles 1 are inserted into the pit using a pile driver, such as... Figure 1 As shown, several groups of sheet piles 1 are connected end to end to form a frame structure, which is generally rectangular. The two ends of the sheet piles 1 are equipped with locks, and adjacent sheet piles 1 are connected by locks. The specific structure of the sheet piles 1 is an application of existing technology, and will not be described in detail here.

[0028] Step 2: After the foundation pit excavation reaches the set depth, install several sets of reinforcing components one by one on the inner wall of each side of the frame structure. The set depth can be set according to the actual needs of the construction site. There are four sets of reinforcing components. By setting the reinforcing components on the inner wall of the sheet pile 1 (the inner side is the side away from the inner wall of the foundation pit, and the outer side is the side close to the inner wall of the foundation pit), the support strength of the sheet pile 1 for the foundation pit can be improved, and the structural strength of the sheet pile 1 can also be improved.

[0029] Step 3: Install the support mechanism. Install several sets of support mechanisms between two adjacent sets of reinforcing components. Adjust the length of the support mechanisms according to the dimensions of the frame structure and lock them in place. There are four sets of support mechanisms, each connected between two adjacent sets of reinforcing components to form a triangular reinforcing structure. This provides further support for the sheet piles 1, which helps improve the structural stability.

[0030] In this embodiment, in step two, each set of reinforcing components includes a reinforcing rod 3 and several connecting frames 2. The reinforcing rod 3 is detachably fixed to the inner wall of the frame structure through several connecting frames 2, and the several connecting frames 2 are detachably and evenly distributed on the inner wall of the frame structure.

[0031] Specifically, such as Figure 1 As shown, the reinforcing components consist of four groups. The reinforcing rods 3 are generally rectangular structures. Each reinforcing rod 3 is detachably fixed to the inner wall of the frame structure via several connecting brackets 2. In this structure, the inner direction is away from the inner wall of the pit, and the outer direction is close to the inner wall of the pit. Figure 2 As shown, the connecting frame 2 is generally fixed to the inner wall of the frame structure by bolts. Of course, the frame structure and the connecting frame 2 are provided with mounting holes for bolts to pass through. Generally, each reinforcing rod 3 is provided with three connecting frames 2. The three connecting frames 2 are evenly distributed on the inner wall of the frame structure to improve the stability of the connection between the reinforcing rod 3 and the frame structure, which can improve the stability of the support of the frame structure.

[0032] In this embodiment, the connecting frame 2 has a U-shaped structure, which is fastened to the reinforcing rod 3 and detachably fixed to the inner wall of the frame structure. Figure 2 As shown, the connecting frame 2 is fastened to the reinforcing rod 3. That is, the connecting frame 2 is provided with a U-shaped opening groove. During assembly, the reinforcing rod 3 passes through the U-shaped opening groove, which can enhance the limiting effect on the reinforcing rod 3 and prevent the reinforcing rod 3 from coming out.

[0033] In this embodiment, in step three, the two ends of each set of support mechanisms are respectively hinged to the set positions of two adjacent reinforcing rods 3 and together with the two adjacent reinforcing rods 3, they form the reinforcing structure.

[0034] The reinforcing structure is triangular. For example... Figure 1 As shown, there are four sets of support mechanisms 4, which are respectively set between two adjacent reinforcing rods 3. At the same time, the two ends of the support mechanisms 4 are hinged to the middle of the reinforcing rods 3 to form a stable triangular reinforcing structure. By forming a triangular reinforcing structure, the structural stability can be improved. At the same time, the multiple sets of support mechanisms 4 and multiple reinforcing rods 3 form a ring-shaped force transmission path, which is conducive to the distribution of force. When one side wall of the frame structure is subjected to external force, the force can be transmitted to the adjacent side walls through the support mechanisms 4, thereby further improving the support strength of the frame structure and thus improving the safety of the entire device.

[0035] In this embodiment, the support mechanism includes a sliding frame 41, a sliding rod I 46, and a sliding rod II 49. One end of the sliding rod I 46 is hinged to one of the reinforcing rods 3, and the other end of the sliding rod I 46 slides through the sliding frame 41. One end of the sliding rod II 49 is hinged to another reinforcing rod 3 adjacent to one of the reinforcing rods 3, and the other end of the sliding rod II 49 slides through the sliding frame 41. The positions of the sliding rod I 46 and the sliding rod II 49 relative to the sliding frame 41 are adjustable and can be locked, so that the length of the support mechanism is adjustable and can be locked.

[0036] Specifically, such as Figure 1 As shown, one end of sliding rod I 46 and sliding rod II 49 are respectively hinged to two adjacent reinforcing rods 3, and the other end of sliding rod I 46 and sliding rod II 49 slides through the sliding frame 41. Thus, by adjusting the distance between the ends of the two sliding rods I 46 and sliding rod II 49 located in the sliding frame 41, the length of the support mechanism 4 can be adjusted.

[0037] In this embodiment, the support mechanism further includes a threaded post 43, two fixed plates 42, and two threaded sleeves 45. The two fixed plates 42 are disposed inside the sliding frame 41. The threaded post 43 passes through the two fixed plates 42 in sequence and is rotatably connected to the two fixed plates 42. The two threaded sleeves 45 are respectively sleeved on both ends of the threaded post 43 and threadedly engaged with the threaded post 43. The sliding rod I 46 and sliding rod II 49 are respectively fixedly connected to the outer periphery of the two threaded sleeves 45, and both ends of the threaded post 43 extend into the two sliding rods I 46 and sliding rod II 49 respectively.

[0038] Specifically, such as Figure 3As shown, the threaded post 43 is disposed within the sliding frame 41. Two fixed plates 42 are spaced apart along the axial direction of the sliding frame 41 and are fixedly connected to the sliding frame 41. The two fixed plates 42 have threaded holes through which the threaded post 43 passes. Sliding rods I 46 and II 49 are hollow structures. When the threaded sleeve 45 is fitted onto the threaded post 43, both ends of the threaded post 43 are located within the sliding rods I 46 and II 49, respectively. The threaded post 43 has two external threads that engage with the threaded sleeve 45, and the two external threads have opposite directions of rotation. Therefore, by rotating the threaded post 43 clockwise or counterclockwise, the two threaded sleeves 45 can move in opposite directions or towards each other. This allows for length adjustment of the support mechanism 4. The sliding rods I 46 and II 49 can be fixedly mounted on the outer periphery of the threaded sleeve 45 by welding.

[0039] In this embodiment, the support mechanism further includes two limiting blocks, which are fixedly disposed at both ends of the threaded post 43. During assembly, the threaded sleeve 45 is first fitted onto the threaded post 43, then the limiting blocks are welded to both ends of the threaded post 43, and finally the sliding rod I 46 and sliding rod II 49 are welded to the outer periphery of the threaded sleeve 45. By setting the limiting blocks, the sliding rod I 46 and sliding rod II 49 can be prevented from separating from the threaded post 43 during sliding.

[0040] In this embodiment, the support mechanism further includes a movable plate 48 and two sliders 47 disposed within the sliding frame 41. The two sliders 47 are disposed one-to-one on the outer periphery of the sliding rod I 46 and the sliding rod II 49. The movable plate 48 is disposed at the top and bottom of the sliders 47 and forms an I-shaped structure with the sliders 47. The I-shaped structure is slidably disposed on the sliding frame 41.

[0041] Specifically, such as Figure 3 As shown, each set of support mechanisms 4 includes two movable plates 48, and each movable plate 48 includes two sliders 47. The two movable plates 48 are set inside the sliding frame 41. The two movable plates 48 are located one-to-one on the outside of the two fixed plates 42, with the outside being the side closest to the threaded sleeve 45. The two sliders 47 are respectively set at the top and bottom of the movable plates 48, thus forming an I-shaped structure with the movable plates 48. The I-shaped structure is slidably connected to the sliding frame 41. Generally, the sliding frame 41 is a frame structure, which facilitates the assembly and installation of various components. At the same time, by forming an I-shaped structure, the sliding stability of sliding rod I 46 and sliding rod II 49 when sliding relative to the sliding frame 41 can be improved.

[0042] In this embodiment, the support mechanism further includes an operating part 44, which is fixedly sleeved on the threaded post 43 and located between two fixed plates 42. The operating part 44 can be a hexagonal prism structure, fixedly mounted on the threaded post 43 and located between the two fixed plates 42, so that during use, the user can hold the operating part 44 and rotate the threaded post 43 to adjust the length of the support mechanism 4, making it convenient for the user to use.

[0043] In this embodiment, the reinforcing rod 3 is provided with a hinge portion 5, and the sliding rod I 46 and sliding rod II 49 are respectively provided with hinge seats 6 that cooperate with the hinge portion 5. The hinge portion 5 can be fixedly connected to the reinforcing rod 3 by welding, and the hinge seats 6 can be fixedly connected to the sliding rod I 46 and sliding rod II 49 respectively by welding. The hinge seats 6 are provided with an opening slot, and the hinge seats 6 and the hinge portion 5 are provided with hinge holes for the hinge shaft to pass through. The hinge shaft can be a bolt, and the bolts pass through the hinge holes one by one and are fixed by nuts.

[0044] The present invention provides a method for foundation pit support for urban bridges. After the foundation pit is excavated to a certain depth, a pile driver is used to insert several sets of steel sheet piles 1 into the foundation pit, so that the steel sheet piles 1 reach a predetermined depth (set according to the construction situation). The foundation pit is then excavated again. When the foundation pit reaches the set depth (set according to the construction requirements), a reinforcing component is installed. The reinforcing rod 3 is installed on the inner side wall of the steel sheet pile 1 through the connecting frame 2. A support mechanism is installed. According to the size of the frame structure, the length of the support mechanism is adaptively adjusted by rotating the operating part 44, so that the support mechanism can provide stable support for the steel sheet pile 1. Finally, the length of the support mechanism is locked.

[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for foundation pit support for urban bridges, characterized in that: Includes the following steps: Step 1: Excavation of the foundation pit. Several sets of steel sheet piles are inserted into the foundation pit using a pile driver to support the side walls of the foundation pit. At the same time, the several sets of steel sheet piles form a frame structure. Step 2: After the foundation pit excavation reaches the set depth, install several sets of reinforcing components one by one on the inner side wall of each side of the frame structure. Step 3: Install the support mechanism. Install several sets of support mechanisms between two adjacent sets of reinforcing components. Adjust the length of the support mechanism according to the size of the frame structure and lock it.

2. The method for foundation pit support for urban bridges according to claim 1, characterized in that: In step two, each set of reinforcing components includes a reinforcing rod and several connecting frames. The reinforcing rod is detachably fixed to the inner wall of the frame structure through several connecting frames, and the several connecting frames are detachably and evenly distributed on the inner wall of the frame structure.

3. The method for foundation pit support for urban bridges according to claim 2, characterized in that: The connecting frame has a U-shaped structure, which is fastened to the reinforcing rod and detachably fixed to the inner wall of the frame structure.

4. The method for foundation pit support for urban bridges according to claim 2, characterized in that: In step three, the two ends of each set of support mechanisms are respectively hinged to the set positions of two adjacent reinforcing rods and together with the two adjacent reinforcing rods to form the reinforcing structure; The reinforcing structure is triangular.

5. The method for foundation pit support for urban bridges according to claim 4, characterized in that: The support mechanism includes a sliding frame, sliding rod I, and sliding rod II. One end of sliding rod I is hinged to one of the reinforcing rods, and the other end of sliding rod I slides through the sliding frame. One end of sliding rod II is hinged to another reinforcing rod adjacent to one of the reinforcing rods, and the other end of sliding rod II slides through the sliding frame. The positions of sliding rod I and sliding rod II relative to the sliding frame are adjustable and can be locked, so that the length of the support mechanism is adjustable and can be locked.

6. The method for foundation pit support for urban bridges according to claim 5, characterized in that: The support mechanism also includes a threaded column, two fixed plates, and two threaded sleeves. The two fixed plates are disposed inside the sliding frame. The threaded column passes through the two fixed plates in sequence and is rotatably connected to the two fixed plates. The two threaded sleeves are respectively sleeved on both ends of the threaded column and are threadedly engaged with the threaded column. The sliding rod I and sliding rod II are respectively fixedly connected to the outer periphery of the two threaded sleeves, and the two ends of the threaded column extend into the two sliding rods I and sliding rod II respectively.

7. The method for foundation pit support for urban bridges according to claim 6, characterized in that: The support mechanism also includes two limiting blocks, which are fixedly installed at both ends of the threaded column.

8. The method for foundation pit support for urban bridges according to claim 6, characterized in that: The support mechanism also includes a movable plate and two sliders disposed within the sliding frame. The two sliders are disposed one-to-one on the outer periphery of sliding rod I and sliding rod II. The movable plate is disposed on the top and bottom of the sliders and forms an I-shaped structure with the sliders. The I-shaped structure is slidably disposed on the sliding frame.

9. The method for foundation pit support for urban bridges according to claim 6, characterized in that: The support mechanism also includes an operating part, which is fixedly sleeved on the threaded column and located between two fixed plates.

10. The method for foundation pit support for urban bridges according to claim 6, characterized in that: The reinforcing rod is provided with a hinge portion, and the sliding rod I and sliding rod II are respectively provided with hinge seats that cooperate with the hinge portion.

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