A combined structure and construction method of driven piles and "I"-shaped gravity anchors

Abstract

This invention belongs to the field of bridge engineering technology, specifically relating to a combination structure and construction method of driven piles and "I"-shaped gravity anchorages. The gravity anchorage combination structure includes a gravity anchorage and a group of driven piles located at the front end of the gravity anchorage. The gravity anchorage has an "I"-shaped structure, including a rear anchorage, a front anchorage, an anchor waist, and an anchor body. The rear anchorage and the front anchorage are arranged parallel to each other. The cross-section of the front anchorage is a trapezoid with a wider front and narrower rear. Several grooves running from top to bottom are evenly spaced on the front anchorage surface of the front anchorage. A rectangular reinforcement area with the same width as the front anchorage is divided in front of the front anchorage. The anchor waist is located between the front and rear anchorages, and the front, rear, and anchor waists are in the shape of an "I". The anchor body is located above the anchor waist. The driven pile group is located within the rectangular reinforcement area to reinforce the passive earth pressure zone at the front end of the front anchorage. This invention enables the use of smaller anchorage foundations to more efficiently meet various stability indicators of bridges.

Description

Technical Field

[0001] This invention belongs to the field of bridge engineering technology, specifically relating to a combined structure and construction method of driven piles and "I"-shaped gravity anchorages. Background Technology

[0002] Currently, anchorages are a crucial component of suspension bridges, serving as a key element in ensuring the stability of the main structure. Various structural types of anchorages exist in bridge engineering, such as gravity anchorages, rock anchorages, tunnel anchorages, and pile anchorages. Gravity anchorages, with their well-defined interaction mechanism with surrounding rock and strong adaptability, are widely used. However, gravity anchorages primarily rely on their own weight and the frictional resistance between them and the foundation to balance the tension of the main cable. This results in significant excavation and concrete pouring volumes. Furthermore, when encountering foundation soils with poor mechanical properties, increasing the anchorage's volume is often necessary to ensure sufficient load-bearing capacity, which greatly increases project costs. The substantial amount of excavation also has a very negative environmental impact.

[0003] In existing technologies, gravity anchors often improve their bearing capacity by increasing the anchor area and using a combination of foundations such as pile foundations at the bottom of the foundation. However, these methods have high requirements for safety and stability during construction and cannot fully utilize the horizontal resistance of the soil in front of the anchor. Summary of the Invention

[0004] This invention provides a combined structure and construction method of driven piles and "I"-shaped gravity anchors, which fully and efficiently utilizes the bearing capacity of the soil in front to achieve the stability of bridge foundations with a relatively small anchor foundation, overcoming the problems of large concrete pouring volume and great influence of geological conditions in existing gravity anchors.

[0005] The technical solution adopted by this invention to solve its technical problem is: a combined structure of driven piles and "I"-shaped gravity anchors, including a gravity anchor and a group of driven piles located at the front end of the gravity anchor, wherein:

[0006] Gravity anchorages have an I-shaped structure, which includes a rear anchorage, a front anchorage, an anchor waist, and an anchor body;

[0007] The rear anchor is set parallel to and opposite to the front anchor;

[0008] The front anchor has a trapezoidal cross-section that is wider at the front and narrower at the back;

[0009] Several grooves running from top to bottom are set at equal intervals on the front anchor face of the front anchorage;

[0010] A rectangular reinforcement zone with the same width as the front anchor is defined in front of the front anchor.

[0011] The anchor waist is located between the front anchor and the rear anchor, and the front anchor, the rear anchor, and the anchor waist are in an I-shape.

[0012] The anchor body is positioned above the anchor waist;

[0013] The driven pile group is set in the rectangular reinforcement area to reinforce the passive earth pressure zone at the front end of the front anchor.

[0014] As a further preferred embodiment of the present invention, the driven pile group includes a capping beam, a plurality of foundation piles, and a plurality of inclined piles, wherein:

[0015] The capping beam is set on top of several foundation piles and several inclined piles;

[0016] A number of foundation piles and a number of inclined piles are set up in a one-to-one correspondence, and the tops of the foundation piles and the inclined piles are all anchored into the capping beam.

[0017] As a further preferred embodiment of the present invention, the burial depth of the front anchor is greater than that of the rear anchor, and the burial depth of the rear anchor is not less than 2 / 3 of the burial depth of the front anchor.

[0018] As a further preferred embodiment of the present invention, the angle between the side of the front anchor and the front anchor surface is 45-60°.

[0019] As a further preferred embodiment of the present invention, the front anchor, anchor waist, rear anchor, and anchor body are integrally cast reinforced concrete components.

[0020] As a further preferred embodiment of the present invention, the front anchor, the anchor waist, and the rear anchor are of equal thickness.

[0021] As a further preferred embodiment of the present invention, the width of the anchor waist is 1 / 2 to 2 / 3 of the width of the rear anchor.

[0022] A construction method for a combined structure of driven piles and "I"-shaped gravity anchors is also provided, including the following steps:

[0023] Step S1: Excavate the anchorage foundation pit:

[0024] Excavation of anchorage foundation pits, including sloping excavation, requires slope protection and construction of retaining piles for the foundation pit;

[0025] Step S2, Subbase construction:

[0026] Pour concrete at the bottom of the foundation pit and level the surface;

[0027] Step S4: Pour anchorage concrete:

[0028] The rear anchor, front anchor, anchor waist, and anchor body are cast into a single gravity anchor assembly structure and then cured.

[0029] Step S5: Constructing and driving the pile group:

[0030] Once the anchor concrete reaches the strength required for the current working conditions, the driven pile group will be constructed within the rectangular reinforcement area.

[0031] As a further preferred embodiment of the present invention, in step S2, a 40-60cm thick layer of C25 plain concrete is poured.

[0032] As a further preferred embodiment of the present invention, the specific construction steps of the driven pile group in step S5 are as follows:

[0033] Step S5-1: Drive the foundation piles and inclined piles in sequence;

[0034] Step S5-2: After the pile driving is completed, the cast-in-place capping beam is constructed on top of the foundation piles and inclined piles to form an integral whole with the foundation piles and inclined piles.

[0035] By employing the above technical solutions, the present invention has the following beneficial effects compared to the prior art:

[0036] 1. In the driven pile and "I"-shaped gravity anchor combination structure provided by the present invention, the width of the front anchor gradually changes from front to back, and a uniformly distributed groove is provided on the front anchor surface, which can increase the contact area between the front anchor surface and the soil and improve the horizontal bearing capacity of the front anchor surface.

[0037] 2. The driven pile and "I"-shaped gravity anchor combination structure provided by the present invention is suitable for situations with poor soil mechanical properties. By using driven piles to reinforce the foundation soil, the soil resistance of the foundation soil at the front end of the anchor structure can be significantly increased.

[0038] 3. The driven pile and "I"-shaped gravity anchor combination structure provided by the present invention adopts an "I"-shaped structure, which can reduce the amount of excavation and concrete used in the anchor foundation and save costs. Attached Figure Description

[0039] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0040] Figure 1 This is a three-dimensional structural diagram of the overall structure of the present invention;

[0041] Figure 2 This is a schematic diagram of the overall planar structure of the present invention;

[0042] Figure 3 This is a schematic diagram of the overall structural elevation of the present invention.

[0043] In the diagram: 1-gravity anchor, 2-front anchor, 3-sunken pile group, 4-anchor waist, 5-rear anchor, 6-front anchor face, 7-side of front anchor, 8-groove, 9-anchor body, 10-rectangular reinforcement area, 11-inclined pile, 12-capping beam, 13-foundation pile. Detailed Implementation

[0044] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the invention, and therefore only show the components relevant to the invention.

[0045] In the description of this invention, it should be understood that the terms "left side," "right side," "upper part," "lower part," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and 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. "First," "second," etc., do not indicate the importance of the components, and therefore should not be construed as a limitation of this invention. The specific dimensions used in this embodiment are only for illustrating the technical solution and do not limit the scope of protection of this invention.

[0046] Example 1

[0047] This embodiment provides a preferred implementation, a combined structure of driven piles and "I"-shaped gravity anchors, including a gravity anchor 1 and a group of driven piles 3 disposed at the front end of the gravity anchor 1, wherein:

[0048] The aforementioned gravity anchorage 1 has an I-shaped structure, comprising a rear anchorage 5, a front anchorage 2, an anchor waist 4, and an anchor body 9, with the specific structure as follows:

[0049] The aforementioned rear anchor 5 is arranged parallel to and opposite to the front anchor 2, and the anchor waist 4 is located between the front anchor 2 and the rear anchor 5. The front anchor 2, rear anchor 5, and anchor waist 4 form an I-shape. The I-shaped structure can reduce the excavation volume and concrete usage of this gravity anchor combination structure foundation, thus saving costs.

[0050] The aforementioned front anchor 2 has a trapezoidal cross-section that is wider at the front and narrower at the rear to increase the contact area between the front anchor surface 6 and the soil. Preferably, the angle between the side 7 of the front anchor 2 and the front anchor surface 6 is 45-60°. The 45-60° range is the diffusion angle range for horizontal load transmission, resulting in optimal force transmission efficiency.

[0051] Furthermore, the embedment depth of the front anchor 2 is greater than that of the rear anchor 5, and the embedment depth of the rear anchor 5 is not less than 2 / 3 of the embedment depth of the front anchor 2. The greater embedment depth of the front anchor 2 compared to the rear anchor 5 significantly improves the overturning resistance of this gravity-type anchorage composite foundation. The requirement that the embedment depth of the rear anchor 5 is not less than 2 / 3 of the embedment depth of the front anchor 2 is based on the general foundation embedment depth requirement; a significant difference in embedment depth between the front and rear anchors will lead to changes in the foundation failure mode.

[0052] Several grooves 8, each of the same width, are evenly spaced and run vertically through the front anchor surface 6 of the front anchor 2. These grooves further increase the contact area between the front anchor surface 6 and the soil, thereby improving the horizontal bearing capacity of the front anchor surface 6.

[0053] The aforementioned anchor body 9 is located above the anchor waist 4; the cross-section of the anchor body 9 is triangular, which is used to fix the main cable of the bridge.

[0054] When the soil mechanical properties are poor, to improve the adaptability of this gravity anchorage combination structure, a rectangular reinforcement zone 10 with the same width as the front anchorage 2 is defined in front of the front anchorage 2. A pile group 3 is installed within the rectangular reinforcement zone 10 to reinforce the passive earth pressure zone at the front end of the front anchorage 2, thereby increasing soil resistance and enhancing the bearing capacity of this gravity anchorage combination structure. Preferably, the long side of the rectangular reinforcement zone 10 is the same width as the front anchorage surface 6; this achieves the best effect.

[0055] Specifically, the aforementioned pile group 3 includes a capping beam 12, a number of foundation piles 13, and a number of inclined piles 11. The capping beam 12 is installed on top of the foundation piles 13 and the inclined piles 11; the foundation piles 13 and the inclined piles 11 are arranged in a one-to-one correspondence, and the tops of the foundation piles 13 and the inclined piles 11 are all anchored into the capping beam 12.

[0056] Furthermore, the front anchorage 2, anchor waist 4, rear anchorage 5, and anchor body 9 are integrally cast reinforced concrete components. The front anchorage 2, anchor waist 4, and rear anchorage 5 are all of equal thickness, with a thickness of h. The width b of anchor waist 4 is 1 / 2 to 2 / 3 of the width B of rear anchorage 5. The width b of anchor waist 4 can be determined by the designer based on the specific conditions of the engineering site, and the calculation is carried out in accordance with the bridge foundation design specifications.

[0057] This implementation plan also provides a construction method for a combined structure of driven piles and "I"-shaped gravity anchors, specifically including the following steps:

[0058] Step S1: Excavate the anchorage foundation pit:

[0059] Excavation of anchorage foundation pits, including sloping excavation, requires slope protection and construction of retaining piles for the foundation pit;

[0060] Step S2, Subbase construction:

[0061] Pour concrete at the bottom of the foundation pit and level the surface;

[0062] Furthermore, in step S2, a 40-60cm thick layer of C25 plain concrete is poured.

[0063] Step S3, Rebar Binding:

[0064] First, the specific location of the anchorage is laid out, and then the anchorage steel reinforcement cage is tied.

[0065] Step S4: Pour anchorage concrete:

[0066] The rear anchor 5, the front anchor 2, the anchor waist 4, and the anchor body 9 are cast into one piece to form a gravity anchor combination structure and then cured.

[0067] Step S5: Construction of pile group 3:

[0068] After the anchorage concrete reaches the strength required for the current working conditions, the driven pile group 3 will be constructed within the rectangular reinforcement area 10. The specific construction steps for driven pile group 3 in step S5 are as follows:

[0069] Step S5-1: Drive the foundation piles 13 and inclined piles 11 in sequence;

[0070] Step S5-2: After the pile driving is completed, the cast-in-place capping beam 12 is constructed on the top of the foundation pile 13 and the inclined pile 11, forming an integral whole with the foundation pile 13 and the inclined pile 11.

[0071] After the anchorage concrete reaches the strength required for the current working conditions, the construction of pile group 3 will proceed. The pile driving work of foundation pile 13 and inclined pile 11 will be carried out in sequence. After the pile driving is completed, the cast-in-place capping beam will be constructed on the top of foundation pile 13 and inclined pile 11 to form an integral whole with foundation pile 13 and inclined pile 11.

[0072] Those skilled in the art will understand that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless defined as herein.

[0073] The meaning of "and / or" as used in this application includes both situations where each exists alone or both exist simultaneously.

[0074] The term "connection" as used in this application can mean a direct connection between components or an indirect connection between components through other components.

[0075] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A construction method for a combined structure of driven piles and "I"-shaped gravity anchors, characterized in that: The structure includes a gravity anchor (1) and a pile group (3) located at the front end of the gravity anchor (1), wherein: The gravity anchorage (1) has an I-shaped structure, which includes a rear anchorage (5), a front anchorage (2), an anchor waist (4), and an anchor body (9). The rear anchor (5) is set parallel to and opposite to the front anchor (2); The front anchorage (2) has a trapezoidal cross-section that is wider at the front and narrower at the back; Several grooves (8) are provided at equal intervals on the front anchor surface (6) of the front anchor (2) from top to bottom. A rectangular reinforcement area (10) with the same width as the front anchor (2) is divided in front of the front anchor (2); The anchor waist (4) is located between the front anchor (2) and the rear anchor (5), and the front anchor (2), the rear anchor (5) and the anchor waist (4) are in the shape of an I-shape; The anchor body (9) is positioned above the anchor waist (4); The driven pile group (3) is set within the rectangular reinforcement area (10) to reinforce the passive earth pressure zone at the front end of the front anchor (2); the driven pile group (3) includes a capping beam (12), several foundation piles (13), and several inclined piles (11), wherein: The capping beam (12) is set on top of several foundation piles (13) and several inclined piles (11); A number of foundation piles (13) and a number of inclined piles (11) are set in a one-to-one correspondence, and the tops of the foundation piles (13) and the inclined piles (11) are all anchored into the capping beam (12). The construction method includes the following steps: Step S1: Excavate the anchorage foundation pit: Excavation of anchorage foundation pits, including sloping excavation, requires slope protection and construction of retaining piles for the foundation pit; Step S2, Subbase construction: Pour concrete at the bottom of the foundation pit and level the surface; Step S4: Pour anchorage concrete: The rear anchor (5), front anchor (2), anchor waist (4), and anchor body (9) are cast into a single gravity anchor combination structure and then cured. Step S5: Construction of driven pile group (3): After the anchor concrete reaches the strength required for the current working conditions, the driven pile group (3) is constructed in the rectangular reinforcement area (10).

2. The construction method of the combined structure of driven piles and "I"-shaped gravity anchors according to claim 1, characterized in that: The burial depth of the front anchor (2) is greater than that of the rear anchor (5), and the burial depth of the rear anchor (5) is not less than 2 / 3 of the burial depth of the front anchor (2).

3. The construction method of the combined structure of driven piles and "I"-shaped gravity anchorages according to claim 1, characterized in that: The angle between the side (7) of the front anchor (2) and the front anchor face (6) is 45-60°.

4. The construction method of the combined structure of driven piles and "I"-shaped gravity anchors according to claim 1, characterized in that: The front anchor (2), anchor waist (4), rear anchor (5), and anchor body (9) are integrally cast reinforced concrete components.

5. The construction method of the combined structure of driven piles and "I"-shaped gravity anchors according to claim 1, characterized in that: The front anchorage (2), anchor waist (4), and rear anchorage (5) are of equal thickness.

6. The construction method of the combined structure of driven piles and "I"-shaped gravity anchors according to claim 1, characterized in that: The width of the anchor waist (4) is 1 / 2 to 2 / 3 of the width of the rear anchor (5).

7. The construction method of the combined structure of driven piles and "I"-shaped gravity anchors according to claim 1, characterized in that: In step S2, a 40-60cm thick layer of C25 plain concrete is poured.

8. The construction method of the combined structure of driven piles and "I"-shaped gravity anchors according to claim 1, characterized in that: In step S5, the specific construction steps for driving pile group (3) are as follows: Step S5-1: Drive the foundation piles (13) and inclined piles (11) in sequence; Step S5-2: After the pile driving is completed, the cast-in-place capping beam (12) is constructed on the top of the foundation pile (13) and the inclined pile (11) to form an integral whole with the foundation pile (13) and the inclined pile (11).

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