Underwater pier scouring treatment structure
By setting up cofferdams and temporary support around the bridge pier, pouring concrete to fill grooves, forming a solid structure, the problem of insufficient load-bearing capacity of the bridge foundation under water flow erosion is solved, and an efficient anti-swishing effect is achieved.
Patent Information
- Application Number
- CN202422075794.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-26
- Publication Date
- 2025-07-01
- Estimated Expiration
- 2034-08-26
AI Technical Summary
The existing technology has insufficient load-bearing capacity of the bridge foundation under the erosion of water flow. The existing treatment methods are poor in adaptability, difficult to construct and costly in high-speed water flow, and cannot effectively repair the washed parts.
A cofferdam is installed around the bridge pier to isolate the internal and external water environment, prevent the cofferdam from deforming through temporary support, and pour concrete into filling grooves on the inside of the cofferdam to form an embedded structure to enhance the anti-shrinkage ability.
It improves the anti-shrinking capability of the bridge pier foundation, adapts to high-speed water flow, is easy to construct, reduces construction difficulty and cost, and is suitable for water piers of various shapes.
Smart Images
Figure CN223048068U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of bridge disease prevention and control, in particular to a scour treatment structure for piers in water. Background Art
[0002] The foundation of a bridge located in a river may have the problem of foundation scour under the perennial scouring of water flow. The sediment and pebbles near the pier are washed away, exposing the rock surface at the base, and the rock may have pits under the continuous impact of the water flow. As the pits increase, the bottom of the bridge foundation is hollowed out, affecting the bearing capacity of the structural foundation.
[0003] To ensure the bearing capacity of the bridge foundation, the following measures are often taken in the prior art to reduce the scour of the foundation in water: The stone pitching method is a commonly used method for treating the scour of the bridge foundation in water; there is also a method of setting up a retaining structure after building an island. After pumping out the water in the retaining structure, the pier and the riverbed are exposed for reinforcement treatment; in addition, a protection ring is set to reduce the energy of the downward-flowing water and reduce the scour of the pier; for a newly built bridge, the enlarged foundation method can also be used to reduce the scour of the foundation in water. For the above methods, there are the following disadvantages:
[0004] During the actual construction of the stone pitching method, it is not easy to control the construction accuracy of the stone pitching and evaluate the effect of the stone pitching. Moreover, the stone pitching is generally arranged in a large plane range, which may occupy part of the underwater space in some rivers with high navigation requirements; after the stone pitching is completed, monitoring needs to be strengthened in the later stage, especially for the riverbed with exposed rocks. When necessary, additional stone pitching is required to prevent the stone pitching from being washed away by the water flow; although the method of pumping water and then repairing the scour can directly and effectively treat the scour problem of the pier, it has poor adaptability to rivers with busy navigation, large water flow velocity and large water depth, and the engineering cost is high; although the method of setting up a protection ring can reduce the degree of scour, it cannot repair the scoured part and is usually used as a supporting protection project; the enlarged foundation method is applicable to the setting during the construction of the bridge and has insufficient adaptability to treat the scour of the pier. In particular, it is not easy to determine the elevation of the enlarged foundation surface. If it is set improperly, it is easy to accelerate the scour.
[0005] How to carry out anti-scour reinforcement treatment on existing piers in a river with rapid water flow to protect the safety of the bridge foundation is an urgent problem that current construction personnel need to solve. Content of the Utility Model
[0006] The purpose of the utility model is to provide a scour treatment structure for piers in water in view of the problem in the prior art that the bearing capacity of the structural foundation of existing piers is insufficient due to the perennial scour of water flow.
[0007] In order to achieve the above purpose, the technical solution adopted by the utility model is as follows:
[0008] A scour treatment structure for a pier in water, comprising a pier located in water, with a cofferdam arranged circumferentially along the pier, and the cofferdam is used to isolate the internal and external water environments; a temporary support is arranged inside the cofferdam; a groove is formed between the cofferdam and the pier, the groove is formed on the riverbed surface, and a concrete structure is filled between the cofferdam and the pier, the concrete structure is higher than the riverbed surface and the concrete structure is filled in the groove.
[0009] In this solution, a cofferdam is set around the existing pier to isolate the internal and external water environments, and a temporary support is set to prevent the cofferdam from deforming under the impact of water flow, reducing the influence of water flow, and creating a static water environment inside the cofferdam, so as to facilitate pouring underwater concrete between the cofferdam and the pier for filling and repairing the scour pits near the pier and the pier foundation; by integrally pouring the filled concrete into the groove, an embedded structure is formed, which is beneficial to improving the anti-scour ability of the concrete structure against water flow. By adopting the above treatment structure, the anti-scour ability of the foundations of existing piers of various shapes in water can be enhanced, thereby ensuring the bearing capacity of the piers and adapting to the scour treatment of piers under the action of high-speed water flow.
[0010] Among them, the above-mentioned cofferdam can be located on the side of the groove away from the pier or inside the groove; the groove can be set as a connected annular structure or arranged at intervals, and the planar shape of the groove can be circular, polygonal, or irregular, not limited to the above examples, as long as the concrete structure can be embedded in the groove to form an integral structure with the structure filled on the riverbed surface.
[0011] As a preferred solution of the present invention, the groove is continuously arranged circumferentially along the pier, the groove is annular, the bottom of the cofferdam is located in the groove, and there is a first gap between the bottom of the cofferdam and the inner side wall of the groove, and the concrete structure is filled in the first gap. By arranging the groove circumferentially around the pier and setting the bottom of the cofferdam in the groove, it is convenient for the positioning and installation of the cofferdam; among them, the cofferdam can be positioned and constructed along the side wall of the groove or in the middle of the groove.
[0012] As a further preferred solution of the present invention, there is a second gap between the cofferdam and the outer side wall of the groove, and the second gap is filled with bagged dry-mixed concrete. That is, the bottom of the cofferdam is fixed in the middle of the groove. Inside the groove, the outside of the cofferdam is filled with bagged dry-mixed concrete at the second gap of the groove. The bagged concrete can solidify into normal concrete when it meets water for consolidation, and the construction is convenient. The inside of the cofferdam is filled with the concrete structure formed by pouring at the first gap of the groove; the bagged concrete and the concrete structure formed by pouring in the groove jointly squeeze the cofferdam to ensure the structural stability and prevent the deformation of the cofferdam structure.
[0013] Fix the cofferdam structure in the center of the groove in this way, so as to fix and install the lower part of the annular cofferdam, reducing the driving difficulty of the cofferdam.
[0014] As another implementable embodiment, the cofferdam can also be driven into moderately weathered or slightly weathered rocks to achieve the fixed installation of the lower part of the cofferdam.
[0015] As a further preferred solution of the present invention, the groove is a connecting groove formed by secant piles. That is, the side of the groove is a combined arc surface, showing a wave shape, with high shear strength and good anti-scouring ability. Other hole-forming methods can also be adopted for the groove, such as milling grooves.
[0016] As a preferred solution of the present invention, the top of the cofferdam is set higher than the water surface, avoiding the water environment inside the cofferdam being affected by the dynamic water outside, so as to facilitate the direct pouring of underwater concrete without pumping water.
[0017] As a preferred solution of the present invention, the cofferdam is a steel sheet pile cofferdam. In this solution, a cofferdam structure formed by splicing steel sheet piles is adopted. The steel sheet pile cofferdam can directly use the finished steel sheet piles for hanging connection. Compared with using straight-sided steel plate members, the material preparation is convenient, and the connection between the steel sheet piles is simple and reliable.
[0018] As a preferred solution of the present invention, the depth of the groove is 2m - 3m.
[0019] As a preferred solution of the present invention, the temporary support adopts a rod-shaped structure, and the temporary support is arranged between the cofferdam and the pier.
[0020] As a preferred solution of the present invention, the water-facing side of the cofferdam is provided with a chamfer, which can play a role in water diversion and reducing the intensity of water flow scouring during the construction process, can better adapt to water flow scouring, and thus facilitate the pouring construction inside the cofferdam.
[0021] As a preferred solution of the present invention, the filling height of the concrete structure is 0.5m - 1.5m, strengthening the bearing strength of the bridge foundation.
[0022] In summary, due to the adoption of the above technical solutions, the beneficial effects of the present invention are:
[0023] A scour treatment structure for piers in water provided by the present invention can enhance the anti-scouring ability of the foundations of existing piers of various shapes in water and adapt to the scour treatment of piers under the action of high-speed water flow. Brief Description of the Drawings
[0024] Figure 1 It is a front elevation structure schematic diagram of a scour treatment structure for piers in water in Embodiment 1.
[0025] Figure 2 is Figure 1 the enlarged view of part A in
[0026] Figure 3 is Figure 1 the plan view of
[0027] Icon: 1 - groove; 2 - cofferdam; 21 - chamfer; 3 - temporary support; 4 - concrete structure; 5 - bagged dry - mixed concrete; 6 - pier; 7 - riverbed; 8 - water surface. Specific embodiments
[0028] The following will describe the present utility model in detail with reference to the accompanying drawings.
[0029] In order to make the purpose, technical solutions and advantages of the present utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present utility model and are not used to limit the present utility model.
[0030] Embodiment 1
[0031] A scour treatment structure for a pier in water, as Figures 1-3 shown, includes a pier 6 located in water, a cofferdam 2 is arranged circumferentially along the pier 6, and the cofferdam 2 is used to isolate the internal and external water environments; a temporary support 3 is arranged inside the cofferdam 2; a groove 1 is arranged between the cofferdam 2 and the pier 6, the groove 1 is formed on the surface of the riverbed 7, and a concrete structure 4 is filled between the cofferdam 2 and the pier 6, the concrete structure 4 is higher than the surface of the riverbed 7 and the concrete structure 4 is filled in the groove 1.
[0032] In this solution, by setting a cofferdam 2 around the existing pier 6 to isolate the internal and external water environments, and by setting a temporary support 3 to prevent the cofferdam 2 from deforming under the impact of water flow, reducing the influence of water flow, a static water environment is created inside the cofferdam 2, so as to facilitate pouring concrete between the cofferdam 2 and the pier 6 for filling, and repairing the scour pits near the pier 6 and the foundation of the pier 6; by integrally pouring the filled concrete into the groove 1, an embedded structure is formed, which is beneficial to improving the anti - scour ability of the concrete structure 4 against water flow. By adopting the above treatment structure, the foundation bearing capacity of the existing pier 6 in water can be enhanced, the construction difficulty is small, and the adaptability to the river is good.
[0033] Specifically, in this embodiment, the groove 1 is continuously arranged along the circumferential direction of the pier 6. The groove 1 is annular. The bottom of the cofferdam 2 is located in the groove 1. There is a first gap between the cofferdam 2 and the inner side wall of the groove 1, and the concrete structure 4 is filled in the first gap. There is a second gap between the cofferdam 2 and the outer side wall of the groove 1, and the second gap is filled with bagged dry-mixed concrete 5. That is, the bottom of the cofferdam 2 is fixed in the middle of the groove 1. Inside the groove 1, the outer side of the cofferdam 2 is filled with bagged dry-mixed concrete 5 at the second gap of the groove 1. The bagged concrete can solidify into normal concrete when encountering water for consolidation, which is convenient for construction. The inner side of the cofferdam 2 is filled with the cast concrete structure 4 at the first gap of the groove 1. The cast concrete is integrally formed with the surface of the riverbed 7 in the groove 1 to form a concrete structure 4 that is a certain height above the riverbed 7. The cofferdam 2 is jointly clamped by the bagged concrete and the cast concrete structure 4 in the groove 1 to ensure the structural stability and prevent the deformation of the cofferdam 2 structure. In this way, the structure of the cofferdam 2 is fixed in the center of the groove 1, and the lower part of the annular cofferdam 2 is fixedly installed.
[0034] During construction, a bored pile is formed around the pier 6 in the water by a rotary drilling rig. The holes are mutually occluded to form a connected deep groove (i.e., the groove 1). The depth of the groove is 2 - 3m and the width is 0.8m - 1.5m. The diameter of the secant pile hole is determined according to the size of the drilling rig equipment. Steel sheet piles are inserted into the formed groove 1 to form a steel sheet pile cofferdam 2. The top of the cofferdam 2 is set higher than the water surface 8 to avoid the water environment inside the cofferdam 2 being affected by the dynamic water outside. The gap between the steel sheet pile and the outer side wall of the groove 1 is filled and compacted with bagged dry-mixed concrete 5. A temporary support 3 is arranged between the steel sheet pile and the pier 6 to maintain the shape stability. The temporary support 3 adopts a rod-shaped structure. One end of the temporary support 3 is welded to the steel sheet pile and the other end abuts against the side wall of the pier 6. When constructing the steel sheet pile, a chamfer 21 is arranged on the water-facing side of the cofferdam 2, which can play a role in water diversion and reducing the intensity of water flow scouring.
[0035] No pumping is carried out in the area surrounded by the steel sheet pile, so that the water head difference inside and outside the cofferdam 2 is the same. The steel sheet pile only needs to bear the dynamic pressure of the flowing water and can adopt a smaller specification.
[0036] At this time, the inside of the cofferdam 2 is a static water environment, and underwater self-compacting concrete can be directly cast. To ensure the anchorage of the newly cast concrete to the riverbed 7, before concrete casting, the riverbed 7 inside the cofferdam 2 should be cleared of the bottom. Through a high-power slurry pump, the loose sand and gravel inside the cofferdam 2 are pumped out. Then, concrete is poured into the cofferdam 2, and the pouring height is 1m above the top surface of the riverbed 7. The formed concrete structure 4 can fill the formed scouring pit, form a protective platform, and can also be used as the retaining wall of the bridge foundation to prevent scouring and guide the water flow to reduce the scouring effect of the water flow on the bridge foundation.
[0037] After that, the steel sheet piles are divided into upper and lower parts, with the underwater concrete pouring as the boundary. The lower part is retained underwater as a permanent structure, which can further improve the anti-scouring performance of the post-cast concrete. The upper part is only used as a construction auxiliary measure and is recycled after the underwater concrete hardens. The upper and lower parts can be constructed as a whole and separated by underwater cutting or other methods during recycling.
[0038] This technology is mainly applicable to the treatment of the scour at the pier 6 on the riverbed 7 where the rock is exposed after the overburden layer is scoured, and can be applicable to the treatment of the scour at the pier 6 in the positions with fast water flow velocity and large water depth. The scour of the pier 6 is mainly composed of three parts: ① the downflow scouring at the front water-facing surface of the pier, ② the vortex scouring of the advancing water flow around the pier, and ③ the wake vortex scour pit at the tail of the pier; corresponding measures are taken respectively for the causes of scour: the lower part of the steel sheet pile is not recycled as a permanent structure, and the depth of the steel sheet pile penetrating into the riverbed by 2-3m can eliminate the scouring effect of the underflow and limit the possible future scour outside the steel sheet pile; the concave-convex outer contour can eliminate the ability of the advancing water flow and reduce the vortex scouring of the advancing water flow around the pier; the chamfers 21 at the front and rear ends of the cofferdam 2 can reduce the scouring intensity of the water-facing surface and the wake vortex intensity.
[0039] The outer contour of the permanent structure of this technology is the steel sheet pile cofferdam 2, which has basically no impact on the navigation and flood discharge of the existing bridge.
[0040] Using the steel sheet pile cofferdam 2 to form a static water environment to directly pour underwater concrete does not require pumping water and sealing the bottom inside the cofferdam 2, which is convenient for construction. At the same time, the requirement for the support strength of the steel sheet pile can be reduced, and the economy is better.
[0041] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.
Claims
1. A structure for treating underwater pier scour, characterized in that: The invention comprises a bridge pier (6) located in water, a cofferdam (2) is arranged along the circumference of the bridge pier (6), and the cofferdam (2) is used to isolate the internal and external water environments; a temporary support (3) is arranged on the inner side of the cofferdam (2); a groove (1) is arranged between the cofferdam (2) and the bridge pier (6), and the groove (1) is formed on the surface of the riverbed (7); a concrete structure (4) is filled between the cofferdam (2) and the bridge pier (6), and the concrete structure (4) is higher than the surface of the riverbed (7) and the concrete structure (4) is filled in the groove (1).
2. The underwater pier scour treatment structure according to claim 1, characterized in that: The groove (1) is continuously arranged along the circumference of the pier (6), the groove (1) is annular, the bottom of the cofferdam (2) is located in the groove (1), there is a gap one between the cofferdam (2) and the inner wall of the groove (1), and the concrete structure (4) is filled in the gap one.
3. The underwater pier scour treatment structure according to claim 2, characterized in that: A second gap is provided between the cofferdam (2) and the outer side wall of the groove (1), and the second gap is filled with bagged dry-mixed concrete (5).
4. The underwater pier scour treatment structure according to claim 3 is characterized in that: The groove (1) is a connecting groove formed by engaging pile holes.
5. The underwater pier scour treatment structure according to claim 1, characterized in that: The top of the cofferdam (2) is arranged above the water surface (8).
6. The underwater pier scour treatment structure according to claim 1, characterized in that: The cofferdam (2) is a steel sheet pile cofferdam.
7. The underwater pier scour treatment structure according to any one of claims 1 to 6, characterized in that: The depth of the groove (1) is 2m-3m.
8. The underwater pier scour treatment structure according to any one of claims 1 to 6, characterized in that: The temporary support (3) adopts a rod-shaped structure, and the temporary support (3) is arranged between the cofferdam (2) and the bridge pier (6).
9. The underwater pier scour treatment structure according to any one of claims 1 to 6, characterized in that: The water-facing surface of the cofferdam (2) is provided with a chamfer (21).
10. The underwater pier scour treatment structure according to any one of claims 1 to 6, characterized in that: The filling height of the concrete structure (4) is 0.5m-1.5m.