Fabricated bridge anchoring enlarged foundation structure

Abstract

The utility model belongs to the technical field of highway bridges, and discloses a fabricated bridge anchoring enlarged foundation structure to solve the technical problems existing in bridge foundations in the prior art. The enlarged foundation structure comprises a prefabricated pier, a prefabricated bearing platform is detachably installed at the bottom of the prefabricated pier, and the bottom of the prefabricated bearing platform is in contact with an original rock stratum; a concrete water suppression skirt is arranged on the edge of the bottom of the prefabricated bearing platform, a pre-stressed anchor cable is arranged between the prefabricated bearing platform and the original rock stratum, an apron is arranged on the edge of the top of the prefabricated bearing platform, and a light filling layer is arranged between the apron and the prefabricated pier. The pre-stressed anchor cable is driven into the rock stratum and then anchored at the top of the prefabricated bearing platform, the rock pre-stressed anchor cable can provide stable foundation support in a limited space, and the foundation structure is very beneficial to the situation that the site is limited or the original land needs to be reserved to the maximum extent for use. The rock anchor cable can utilize the high strength and stability of the rock to improve the anti-seismic property of the foundation and guarantee the structural safety.

Description

Technical Field

[0001] The utility model relates to the technical field of highway bridges, in particular to an assembled bridge anchoring and enlarged foundation structure. Background Art

[0002] The main types of bridge foundations are: expanded foundation, pile foundation and caisson foundation. For bridge foundations located on hard rocks in high-seismic areas, expanded foundation and pile foundation are currently the main methods, but there are the following problems:

[0003] 1. When the pile foundation is expanded, although the rock has high compressive strength and bearing capacity, the rock strata begin to differentiate over time and cracks of varying degrees appear, so that the foundation's anti-overturning stability and anti-slip stability cannot be guaranteed. At the same time, it is relatively weak in construction, normal use, and structural earthquake resistance.

[0004] 2. When pile foundation is used, its construction is difficult, costly, bonding strength is uneven, pile body is difficult to detect, and technical requirements are high. Appropriate technical measures and quality management measures need to be taken to overcome these problems. In particular, the use of low-strength concrete structure to replace the original high-strength rock strata to meet the bearing requirements is not worth the cost.

[0005] CN202320442618.8 discloses an assembled bridge pier, which mainly solves the problem of connection between the assembled pier and the abutment (i.e. the problem of the pier of the bridge substructure), but cannot solve the problems in the above-mentioned bridge foundation.

[0006] Therefore, new solutions are urgently needed to solve the problem that the bridge foundation on hard rock in high-seismic areas cannot meet the requirements of foundation anti-overturning and anti-sliding stability due to rock stratum differentiation and crack development, and the traditional low-strength (30MPa) reinforced concrete bored cast-in-place piles embedded in the rock stratum to replace the original high-strength rock stratum is not worth the cost. Utility Model Content

[0007] The purpose of the utility model is to solve the technical problems existing in the prior art bridge foundation and to provide an assembled bridge anchoring and enlarged foundation structure.

[0008] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0009] An assembled bridge anchoring and enlarged foundation structure comprises a prefabricated bridge pier, the bottom of the prefabricated bridge pier is detachably provided with a prefabricated cap, the bottom of the prefabricated cap is in contact with the original rock layer, the bottom edge of the prefabricated cap is provided with a concrete water suppression skirt, a prestressed anchor cable is installed between the prefabricated cap and the original rock layer, the top edge of the prefabricated cap is provided with an apron, and a lightweight filling layer is provided between the apron and the prefabricated bridge pier.

[0010] Furthermore, a pier flange is provided at the bottom of the prefabricated pier, and a steel plate pedestal flange is provided at the top of the prefabricated cap. The edge of the steel plate pedestal flange contacts the inner side of the apron, and the steel plate pedestal flange, the prefabricated cap and the pier flange are connected by high-strength bolts.

[0011] Further, one end of the prestressed anchor cable is anchored at the top of the prefabricated cap, and the other end of the prestressed anchor cable is anchored in the medium-weathered rock layer below the original rock layer.

[0012] Furthermore, a plurality of anchor holes for installing prestressed anchor cables are evenly distributed along the circumferential direction on the steel plate cap flange and the prefabricated cap.

[0013] Furthermore, an anchor is installed at one end of the prestressed anchor cable close to the prefabricated cap, and the gap between the prestressed anchor cable and the anchor hole is filled with cement slurry.

[0014] Compared with the prior art, the utility model has the following beneficial effects:

[0015] The utility model drives prestressed anchor cables into rock strata and then anchors them on the top of the prefabricated foundation. The rock prestressed anchor cables can provide stable foundation support in a limited space, which is very beneficial for situations where the site is limited or the original land use needs to be retained to the greatest extent. The construction process of the rock anchor cable is relatively simple and does not require earth excavation, which reduces damage to the environment and land. The construction process is relatively fast, which can shorten the construction period, speed up the project progress, and save costs. The rock anchor cable can provide reliable geological support and bearing capacity, and can adapt to complex geological conditions. In addition, as a hard material, rock can provide good seismic bearing capacity. The rock anchor cable can use the high strength and stability of the rock itself to improve the seismic performance of the foundation and ensure the safety of the structure.

[0016] The utility model combines the expanded foundation and the rock anchor cable to form a new structural form of anchored expanded foundation, which can not only meet various needs of bridge load-bearing, durability and stability, but also is relatively convenient in actual construction, saves construction cost and shortens construction period.

[0017] The concrete water suppression skirt of the utility model can drain surface water and prevent surface water from invading the anchoring and enlarged foundation. The apron of the utility model can prevent surface water from flowing into the root of the prefabricated bridge pier, and at the same time, provide a baffle for filling lightweight materials. The reinforced concrete bridge pier and reinforced concrete cap of the utility model can be prefabricated in the factory, and can be transported to the site for installation after the prefabrication is completed and the strength reaches the design requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of the utility model.

[0019] Figure 2 For this utility model Figure 1Top view of the .

[0020] Figure 3 For this utility model Figure 2 Schematic diagram of removing the lightweight filling layer.

[0021] Figure 4 It is a structural schematic diagram of the prestressed anchor cable of the utility model.

[0022] Figure 5 It is a cross-sectional view of the prestressed anchor cable of the utility model.

[0023] Figure 6 for Figure 1 A partial enlarged schematic diagram of part A in the middle.

[0024] The meanings of the accompanying numbers are as follows: 1. Precast pier; 2. Precast cap; 3. Prestressed anchor cable; 4. Steel plate cap flange; 5. Concrete water suppression skirt; 6. Apron; 7. High-strength bolt; 8. Lightweight filling layer; 9. Anchor hole; 10. Anchor; 11. Unbonded steel strand; 12. Grouting pipe; 13. Cement slurry; 14. Original rock layer; 15. Moderately weathered rock layer; 16. Pier flange; 17. Ground line. DETAILED DESCRIPTION

[0025] The utility model is further described below in conjunction with the accompanying drawings and specific implementation methods.

[0026] like Figure 1-6 As shown, an assembled bridge anchoring and enlarged foundation structure includes a prefabricated pier 1, a pier flange 16 is prefabricated at the bottom of the prefabricated pier 1, the pier flange 16 is connected to a steel plate cap flange 4 arranged on the top of a prefabricated cap 2 by high-strength bolts 7, the high-strength bolts 7 are driven into the prefabricated cap 2, the bottom of the prefabricated cap 2 is in contact with the original rock layer 14, a concrete water suppression skirt 5 is provided at the bottom edge of the prefabricated cap 2, a concrete apron 6 is provided at the top edge of the prefabricated cap 2, and a lightweight filling layer 8 is provided between the apron 6 and the prefabricated pier 1. The edge of the steel plate cap flange 4 contacts the inner side of the apron 6. A plurality of anchor holes 9 for installing prestressed anchor cables 3 are evenly distributed along the circumferential direction on the steel plate cap flange 4 and the prefabricated cap 2. A prestressed anchor cable 3 is installed between the prefabricated cap 2 and the original rock layer 14. One end of the prestressed anchor cable 3 is anchored at the top of the prefabricated cap 2, and the other end of the prestressed anchor cable 3 is anchored in the medium weathered rock layer 15 under the original rock layer 14. An anchor 10 is installed at one end of the prestressed anchor cable 3 close to the prefabricated cap 2, and the gap between the prestressed anchor cable 3 and the anchor hole 9 is filled with cement slurry 13.

[0027] Before construction, relevant construction organization design is done, and prefabricated bridge piers 1 and prefabricated caps 2 are prefabricated in the factory in advance. Unbonded steel strands 11, φ25 grouting pipes 12, and OVM anchors 10 related to prestressed anchor cables 3 are prepared in advance according to design documents.

[0028] When the construction site meets the construction conditions and the prefabricated bridge pier 1 and the prefabricated cap 2 meet the design strength requirements, the prefabricated bridge pier 1 and the prefabricated cap 2 can be transported to the site for hoisting and installation.

[0029] After the installation of the prefabricated foundation 2 is completed, the construction of the prestressed anchor cable 3 mainly includes (layout and drilling of the anchor hole 9 → bundling, tensioning and anchoring of the unbonded steel strands 11 → insertion of the φ25 grouting pipe 12 → pouring of 40MPa cement slurry 13 → sealing of the OVM anchor 10).

[0030] The pouring of the concrete water suppression skirt 5 and the prestressed anchor cable 3 can be constructed simultaneously.

[0031] After the prefabricated pier 1 of the main structure and the prefabricated pedestal 2 are connected by the steel plate pedestal flange 4 through the high-strength bolts 7, the concrete apron 6 is constructed. After the construction of the concrete apron 6 is completed and the strength reaches the design requirement, a lightweight filling layer 8 is filled between the apron 6 and the prefabricated pier 1, and the lightweight filling layer 8 is rolled to ensure that the filling is dense.

Claims

1. An assembled bridge anchoring and enlarged foundation structure, comprising a prefabricated bridge pier (1), wherein a prefabricated cap (2) is detachably mounted on the bottom of the prefabricated bridge pier (1), and wherein: The bottom of the prefabricated cap (2) is in contact with the original rock layer (14); a concrete water suppression skirt (5) is provided at the bottom edge of the prefabricated cap (2); a prestressed anchor cable (3) is installed between the prefabricated cap (2) and the original rock layer (14); one end of the prestressed anchor cable (3) is anchored at the top of the prefabricated cap (2); and the other end of the prestressed anchor cable (3) is anchored in a medium-weathered rock layer (15) below the original rock layer (14); an apron (6) is provided at the top edge of the prefabricated cap (2); and a lightweight filling layer (8) is provided between the apron (6) and the prefabricated bridge pier (1).

2. The assembled bridge anchoring and enlarged foundation structure according to claim 1 is characterized by: The bottom of the prefabricated pier (1) is provided with a pier flange (16), the top of the prefabricated cap (2) is provided with a steel plate cap flange (4), and the steel plate cap flange (4), the prefabricated cap (2) and the pier flange (16) are connected by high-strength bolts (7).

3. The assembled bridge anchoring and enlarged foundation structure according to claim 2 is characterized by: The edge of the steel plate base flange (4) contacts the inner side of the apron (6).

4. The assembled bridge anchoring and enlarged foundation structure according to claim 3 is characterized by: The steel plate cap flange (4) and the prefabricated cap (2) are provided with a plurality of anchor holes (9) evenly distributed along the circumferential direction for installing prestressed anchor cables (3).

5. The assembled bridge anchoring and enlarged foundation structure according to claim 4 is characterized by: An anchor (10) is installed at one end of the prestressed anchor cable (3) close to the prefabricated cap (2), and the gap between the prestressed anchor cable (3) and the anchor hole (9) is filled with cement slurry (13).

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