Anti-scouring structure for bridge high-pile pile cap foundation

Abstract

The application relates to an anti-scouring structure for a bridge high-pile pile cap foundation, the high-pile pile cap foundation comprising a pile cap, a group of piles connected with the pile cap, and the group of piles comprising a plurality of pile foundations; the anti-scouring structure comprising: a pile-front water baffle used for being connected with the pile cap, the pile-front water baffle facing a flow-encountering side of the pile cap; a pile-front water collecting pipe fixedly connected with the pile-front water baffle; a pile-front sand collecting groove movably connected with the pile-front water collecting pipe; and a sand collecting guard ring used for being sleeved on the pile foundation. The application provides an anti-scouring structure for a bridge high-pile pile cap foundation, based on the scouring mechanism of the high-pile pile cap foundation, the pile-front water baffle, the pile-front water collecting pipe, the pile-front sand collecting groove and the sand collecting guard ring play a step-by-step and mutually combined flow disturbance and siltation promotion anti-scouring effect. Unlike the riprap protection measures taken when the pier scouring pit has been formed and threatens the safety of the bridge, the application actively collects the silt to ensure that the silt in the original bed surface of the pile foundation is not taken away by scouring as much as possible, the pile body is not damaged, and periodical sweeping and measuring maintenance is not needed.

Description

Technical Field

[0001] This application relates to the field of bridge foundation disaster prevention and mitigation technology, specifically to an anti-scour structure for high-pile bridge foundations. Background Technology

[0002] Bridge construction environments in estuaries or marine areas are complex and varied. Pile cap foundations have strong adaptability and are often used as one of the important foundation types for cross-sea bridges, especially high pile cap foundations. High pile cap foundations include the upper piers, the middle cap, and the lower piles, all of which are water-related foundations.

[0003] Due to the complex hydrodynamic environment, the hydrodynamic characteristics caused by high pile foundations are more complex than those of general bridge piers. In addition, the different structural composition makes the scour problem of high pile foundations of bridges extremely complex and seriously threatens the safety of bridges.

[0004] In estuary or nearshore environments, the sediment near bridge pier foundations is subject to complex hydrodynamic conditions. Apart from some suspended sediment moving in the form of sand waves, the sediment on the bed surface is mainly bedload moving in the form of sand waves. During the formation of the scour pit, a large amount of bedload moving in the form of sand waves will briefly enter the scour pit and then be carried away by the accelerated water flow squeezed into the lower pile foundation. The scour pit is also continuously scourted by the accelerated water flow, and the depth and range of the scour pit continue to increase, resulting in severe local scour.

[0005] Currently, scour prevention measures for high-pile bridge foundations mostly rely on riprap protection. This is often only implemented when scour pits have formed around the piers, the scour depth is close to the warning mud level, and a large amount of sediment near the pier foundation has been carried away, threatening bridge safety. Riprap protection typically employs a multi-layered protection system, requiring a large amount of sandbags or stones. This can damage the piles and necessitates regular sweeping and maintenance. The cost of protecting a single pier is high, ranging from tens of millions to nearly one hundred million yuan. Moreover, even with substantial protective material, the lost skin friction of the pile foundation is difficult to compensate for. Summary of the Invention

[0006] This application provides an anti-scour structure for high-pile foundations of bridges, which solves the technical problems in related technologies where rock-fill protection measures are easily damaged when scour is severe to the point that the depth of the scour pit threatens the safety of the bridge, and where regular sweeping and maintenance are required later.

[0007] This application provides an anti-scour structure for high-pile foundations of bridges.

[0008] A high-pile cap foundation includes a cap and a pile group connected to the cap, wherein the pile group includes multiple pile foundations;

[0009] The erosion protection structure includes:

[0010] A water-retaining plate in front of the pile is used to connect with the pile cap, and the water-retaining plate in front of the pile faces the flow-facing side of the pile cap;

[0011] A water collection pipe in front of the pile is fixedly connected to the water baffle plate in front of the pile.

[0012] A sand collection trough in front of the pile is movably connected to the water collection pipe in front of the pile.

[0013] And a sand-collecting protective ring, used to be fitted onto the pile foundation.

[0014] In some embodiments, there is a gap between the water-retaining plate in front of the pile and the pile foundation.

[0015] In some embodiments, the water collection pipe in front of the pile includes a plurality of interconnected circular pipes, the top of which is open and a plurality of overflow holes are provided on its flow-facing side.

[0016] In some embodiments, there are no gaps between the plurality of said circular tubes.

[0017] In some embodiments, the overflow holes are all the same size, or the overflow holes near the front water baffle of the pile are smaller than the overflow holes away from the front water baffle of the pile.

[0018] In some embodiments, the water collection pipe in front of the pile and the pile foundation have an angle.

[0019] In some embodiments, the pre-pile sand collection trough includes two opposing first connecting plates, a second connecting plate connecting the two first connecting plates, a plurality of rods disposed between the two first connecting plates, and a plurality of biomimetic grasses arranged on the rods. The second connecting plate is movably connected to the pre-pile water collection pipe. There are gaps between the plurality of rods. The rods divide the pre-pile sand collection trough into an upper siltation layer and a lower sand-passing layer.

[0020] In some embodiments, the second connecting plate is located in the upper siltation layer.

[0021] In some embodiments, the height of the lower sand-passing layer is greater than the height of the upper silt-promoting layer.

[0022] In some embodiments, the sand-collecting retaining ring includes a shell with a sand-collecting space, the shell being fitted onto the pile foundation.

[0023] The beneficial effects of the technical solution provided in this application include:

[0024] This application provides an anti-scour structure for high-pile foundations of bridges. Based on the scour mechanism of high-pile foundations, a water-retaining plate in front of the pile blocks the water flow impacting the upstream side of the foundation; a water collection pipe in front of the pile receives part of the water flow blocked by the water-retaining plate, preventing it from directly scouring the bed surface sediment and reducing scour; a sand collection trough in front of the pile slows down and promotes sedimentation in the water flow, causing it to fall into the sand collection trough, and bedload sediment moving in the form of sand waves also enters the sand collection trough, finally collecting in the sand collection ring on the pile foundation. The water-retaining plate, water collection pipe, sand collection trough, and sand collection ring in front of the piles play a progressive and coordinated role in disturbing the flow, promoting siltation, and preventing scour. This reduces the dynamic force of the water flow in front of the high pile foundation, prevents the water flow in front of the pier from entering the pile foundation and scouring the pile foundation sediment, captures suspended and pushed sediment in the incoming water flow, and transports it to the inside of the pile group as much as possible, ensuring that the sediment in the pile group is not carried away by the water flow, minimizing the depth and range of scour of the pile foundation, and ultimately achieving the goal of reducing local scour. Unlike the rock-filling protection measures taken only when the scour pit of the bridge pier has formed and threatens the safety of the bridge, the embodiment of this application actively replenishes sediment to ensure that the original bed sediment inside the pile foundation is not scoured away as much as possible, ensuring that the sediment near the high pile foundation of the bridge is not scourted or that the depth does not threaten the safety of the bridge, does not damage the pile body, and does not require regular sweeping and maintenance. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a side view of an anti-scour structure for a high-pile foundation of a bridge, according to one embodiment of the present invention.

[0027] Figure 2 This is a three-dimensional structural diagram of an anti-scour structure for a high-pile foundation of a bridge, according to one embodiment of the present invention.

[0028] Figure 3 This is a schematic diagram of the structure of the water-retaining plate in front of the pile in one embodiment of the present invention.

[0029] Figure 4 This is a schematic diagram of the structure of the water collection pipe in front of the pile in one embodiment of the present invention.

[0030] Figure 5 This is a schematic diagram of the structure of the sand collection trough in front of the pile in one direction in one embodiment of the present invention.

[0031] Figure 6This is a schematic diagram of the structure of the sand collection trough in front of the pile in another direction in one embodiment of the present invention.

[0032] Figure label:

[0033] 1. High pile cap foundation; 11. Pier; 12. Pile cap; 13. Pile group; 131. Pile foundation; 2. Anti-scour structure; 21. Pile front water retaining plate; 22. Pile front water collection pipe; 221. Circular pipe; 222. Overflow hole; 23. Pile front sand collection trough; 231. First connecting plate; 232. Second connecting plate; 233. Rod; 234. Bionic grass; 235. Upper siltation layer; 236. Lower sand-passing layer; 24. Sand collection ring. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0035] This application provides an anti-scour structure for high-pile foundations of bridges, suitable for cross-sea bridges.

[0036] like Figure 1 As shown, Figure 1 This is a side view of an anti-scour structure for a high-pile foundation of a bridge, according to one embodiment of the present invention.

[0037] The high pile cap foundation 1 includes a pier 11, a pile cap 12, and a pile group 13 connected from top to bottom. The pile group 13 includes multiple pile foundations 131.

[0038] Taking bidirectional flow as an example, in the high pile cap foundation 1, the upper pier 11, the middle cap 12 and the lower pile foundation 131 are all subjected to water flow.

[0039] According to relevant technologies, when the incoming water flows to the high pile cap foundation 1, the upper water flow impacts the upper pier 11, but this part of the water flow has a negligible impact on scouring. The water flow acting on the cap 12, due to its large structural dimensions, will partially form a subsurface flow. This subsurface flow may directly impact the front mud surface of the pile group 13, or it may be dragged into the pile group 13 by the lower water flow, where it is accelerated by the internal compression of the pile group 13 and scours the silt inside the pile group 13. Simultaneously, the presence of the lower pile group 13 makes its scouring situation very complex. After the water flow impacts each pile 131, it forms a subsurface flow on the upstream face of each pile 131, and creates several vortices around the pile 131 to suck up the silt around the individual pile 131. However, due to the bidirectional flow, scouring pits appear in similar scouring patterns in front of and behind the pier. Meanwhile, the gaps between each row of pile foundations 131, unaffected by any obstruction from the pile foundations 131, allow the water flow in this layer to be compressed and accelerated within the gaps, forming a high-speed flow that scours the mud and sand between the gaps, i.e., on both sides of the pile foundations 131, creating scour pits. Subsequently, under the influence of headward scour, the scour pits of individual pile foundations 131 will expand to the entire pile group 13. Gradually, the mud and sand inside the entire pile group 13, as well as the mud and sand pushed into the pile foundations 131 in the form of sand waves, will be scourted and carried away by the complex turbulent flow structure and high-speed water flow to a certain range outside the pile group, posing a certain threat to the safety of the bridge pier foundation.

[0040] This application finds that for a high-pile foundation 1, the elevation of the foundation 12 plays a crucial role in scouring. This is because the foundation 12 has a large structural size, and the water flow impacting its upstream surface will develop into a subsurface flow. Under the action of the water flow below the foundation 12, it will be dragged into the lower pile foundation 131. After being squeezed, it will form a high-speed water flow, which will then scour the silt on the bed surface. Therefore, how to avoid the combined action of the subsurface flow after impacting the foundation 12 and the upstream water flow at the pile foundation 131 to form an accelerated water flow inside the pile foundation is one of the keys to reducing foundation scouring.

[0041] In estuarine and nearshore environments, the scour depth of the high-pile foundation 1 is often determined by marine dynamics and soil conditions. Estuarine and nearshore environments are typically bidirectional tidal environments, thus the scour characteristics of the pier 11 of the high-pile foundation 1 differ from those of unidirectional flow piers. In tidal environments, the flow velocity and direction change over time, causing scour to occur at different times, sometimes during the rising tide and sometimes during the falling tide. Consequently, sediment near the high-pile foundation 1 and at pile 131 is also suspended with the rise and fall of the tidal current. Or, due to the smaller particle size of sediment on the bed surface in estuaries and nearshore environments, most of the bedload sediment usually moves in the form of sand waves. This bedload, moving in sand wave form, is also carried into scour pits by the ebb and flow of the tide. However, due to the constantly changing water flow, the sand waves pushed into the scour pits are eventually carried out of the pits, and sediment inside the scour pits is also continuously carried out, causing the depth and extent of the scour pits to continuously increase. Eventually, when the amount of sediment brought into the scour pits is roughly equal to the amount of sediment carried out, the scour reaches a relatively dynamic equilibrium. Therefore, minimizing the scouring of sediment inside the pile foundation by water flow is the second key to reducing foundation scour.

[0042] In summary, the embodiments of this application reduce erosion by avoiding the formation of accelerated water flow inside the pile foundation and actively replenishing sediment to ensure that the original bed surface sediment inside the pile foundation is not washed away as much as possible.

[0043] like Figure 1 and Figure 2 As shown, where, Figure 1 This is a side view of an anti-scour structure for a high-pile foundation of a bridge, according to one embodiment of the present invention. Figure 2 This is a three-dimensional structural diagram of an anti-scour structure for a high-pile foundation of a bridge, according to one embodiment of the present invention.

[0044] The erosion protection structure 2 includes:

[0045] The pile front water baffle 21 is used to connect with the pile cap 12, and the pile front water baffle 21 faces the flow-facing side of the pile cap 12;

[0046] The water collection pipe 22 in front of the pile is fixedly connected to the water baffle plate 21 in front of the pile.

[0047] The sand collection trough 23 in front of the pile is movably connected to the water collection pipe 22 in front of the pile.

[0048] And sand-collecting protective ring 24, used to be fitted onto pile foundation 13.

[0049] This application provides an anti-scour structure for a high-pile foundation of a bridge. Based on the scour mechanism of the high-pile foundation 1, the water-retaining plate 21 in front of the pile blocks the water flow impacting the upstream side of the foundation 12. The water collection pipe 22 in front of the pile receives part of the water flow blocked by the water-retaining plate 21, preventing it from directly scouring the bed surface silt and reducing scour. The sand collection trough 23 in front of the pile slows down and promotes the sedimentation of the water flow, causing it to fall into the sand collection trough 23. The bedload sediment moving in the form of sand waves also enters the sand collection trough 23 in front of the pile, and is finally collected in the sand collection ring 24 on the pile foundation 131. Through the water-retaining plate 21 in front of the pile and the pile... The front water collection pipe 22, the pile front sand collection trough 23, and the sand collection ring 24 play a progressive and coordinated role in disturbing the flow, promoting siltation, and preventing scour. This reduces the dynamic force of the water flow in front of the high pile foundation 1, prevents the water flow in front of the pier from entering the pile foundation 131 and scouring the pile foundation 131, captures suspended and pushed sediment in the incoming water flow, and transports it to the inside of the pile group 13 as much as possible. This ensures that the sediment in the pile group 13 is not carried away by the water flow, minimizes the scour depth and range of the pile group 13 foundation, and ultimately achieves the goal of reducing local scour. It also has a smaller impact on the evolution and scour of the surrounding bed surface. Unlike the rock dumping protection measures taken only when the scour pit of the bridge pier has formed and threatens the safety of the bridge in related technologies, the embodiment of this application actively replenishes sediment to ensure that the sediment on the original bed surface inside the pile foundation is not scoured away as much as possible. This ensures that the sediment near the high pile foundation of the bridge is not scourted or that the depth does not threaten the safety of the bridge, does not damage the pile body, and does not require regular sweeping and maintenance.

[0050] In the high-pile foundation 1 provided in this embodiment, the marine environment is defined as bidirectional flow, and the angle α between the water flow and the high-pile foundation 1 is between 0° and 10°. Two scour protection structures 2 are provided, symmetrically arranged on the bidirectional water-facing side of the high-pile foundation 1. If the environment is unidirectional flow, the scour protection structure 2 is located on the unidirectional water-facing side of the high-pile foundation 1. The elevation of the bottom of the high-pile foundation 1 is defined as higher than the existing mud surface. The elevation of the bottom of the foundation is related to the combined elevation of the components of the scour protection structure and the scour protection effect, ensuring sufficient and reasonable space arrangement for the pile front water baffle 21, the pile front water collection pipe 22, and the pile front sand collection trough 23.

[0051] The upper pier 11 is a round pier, but it can also be a square pier or other shapes; the middle pile cap 12 is a square pile cap, but it can also be a round pile cap or other shapes; in the lower pile group 13, multiple evenly spaced pile foundations 131 are cylindrical.

[0052] The upper end of the pile front water baffle 21 is connected to the pile cap 12, the pile front water baffle 21 faces the flow-facing side of the pile cap 12, and the lower end is connected to the pile front water collection pipe 22.

[0053] The function of the in-pile baffle 21 is to block water flow within its height range, including some of the downward water flow caused by the upper pile cap 12 and the water flow in front of the in-pile baffle 21. Some of the water flow acting on the in-pile baffle 21 will enter the in-pile water collection pipe 22 at the connection between the in-pile baffle 21 and the in-pile water collection pipe 22. Other water flow will flow downstream from both sides, with less impact on scouring.

[0054] Please refer to the following at the same time Figure 3 , Figure 3 This is a schematic diagram of the structure of the water-retaining plate in front of the pile in one embodiment of the present invention.

[0055] The water-retaining plate 21 in front of the pile is a rectangular thin plate. Its width covers the water-facing area of ​​the pile group 13. Its height is related to the water depth at the bottom of the pile cap and the vertical height of the water collection pipe 22 and the sand collection trough 23 in front of the pile. If it is too high, the force will be too great and affect its stabilization. If it is too low, it will not be able to block part of the water flow. Its thickness has a certain rigidity to ensure that it does not deform after the water flow impact or act on the pile foundation 131 behind it. Of course, the water-retaining plate 21 in front of the pile can also be other shapes.

[0056] In some embodiments, there is a gap between the water-retaining plate 21 in front of the pile and the pile foundation 131.

[0057] There is a gap between the water-retaining plate 21 in front of the pile and the pile foundation 131, which effectively prevents the water flow in front of the pile and under the action of the pile cap 12 from impacting the water-retaining plate 21 in front of the pile, and from transferring the water flow dynamics on the water-retaining plate 21 to the pile foundation 131, thus avoiding unnecessary stress problems on the lower pile foundation.

[0058] Specifically, the water-retaining plate 21 in front of the pile is fixed to the bottom of the pile cap 12 by means of a hoop, screws and nuts, so as to leave a certain distance from the first row of piles 131 below. Of course, the water-retaining plate 21 in front of the pile can also maintain the distance between itself and the pile 131 through other structures.

[0059] The lower end of the water-retaining plate 21 in front of the pile is fixedly connected to the upper end of the water-collecting pipe 22 in front of the pile, such as by screws and nuts. The overall structure should be kept stable in combination with the current hydrodynamic environment.

[0060] Please refer to the following at the same time Figure 4 , Figure 4 This is a schematic diagram of the structure of the water collection pipe in front of the pile in one embodiment of the present invention.

[0061] In some embodiments, the water collection pipe 22 in front of the pile includes a plurality of interconnected circular pipes 221, the top end of the circular pipes 221 being open, and a plurality of overflow holes 222 being provided on the flow-facing side of the circular pipes 221.

[0062] The water collection pipe 22 in front of the pile is fixed at the bottom of the water baffle 21 in front of the pile, and is designed to fit the water baffle 21 in front of the pile to ensure that the maximum amount of water flow enters the circular pipe 221.

[0063] The function of the water collection pipe 22 in front of the pile is to receive part of the water flow blocked by the water baffle 21 in front of the pile through various circular pipes 221. Overflow holes 222 are evenly opened on the flow-facing surface of each circular pipe 221. For the part of the water flow that enters the internal part of the circular pipe 221, since the tail end of the circular pipe 221 is closed and the water flow has a large pressure, it will overflow at a certain flow rate through several overflow holes 222 on the flow-facing surface of the circular pipe 221, thereby offsetting the intensity of the incoming water flow and playing a role in turbulence and flow reduction. At the same time, the water flow that does not enter the circular pipe 221 flows along the circular pipe 221 to the sand collection trough 23 in front of the pile for dissipation, avoiding the water flow from directly scouring the mud surface in front of the pile, minimizing the intensity of the water flow, and preventing the water flow from scouring mud and sand in the lower part and inside of the pile foundation.

[0064] In some embodiments, there are no gaps between the plurality of circular tubes 221.

[0065] There are no gaps between the several round tubes 221 to ensure that they will not break under stress. The round tubes 221 can be tightly fitted together by welding, bonding, or integral molding during manufacturing.

[0066] The width of the pile front water collection pipe 22, which is composed of several circular pipes 221, is equal to the width of the pile front water baffle 21. The length of a single circular pipe 221 is L, and the distance from its tail end to the pile foundation 131 is controlled to be 0.5 to 1.0 times the transverse width of the pile group 13, and is roughly determined to be 2 to 3 times the pier diameter centered on the pier based on the influence range of the scour pit.

[0067] In some embodiments, the overflow holes 222 are of the same size and are evenly arranged on the flow-facing surface of a single circular pipe 221; of course, the overflow holes 222 can also be of different sizes, such as the overflow holes near the front water baffle 21 of the pile being smaller than the overflow holes far from the front water baffle 21 of the pile.

[0068] In some embodiments, the water collection pipe 21 in front of the pile and the pile foundation 131 have an angle.

[0069] There is an angle between the pile front water collection pipe 21 and the pile foundation 131, that is, the pile front water collection pipe 22 and the bed surface are arranged at a certain angle θ, where θ is 30° to 60°, so that the water flow can be easily dissipated in the pile front water collection pipe 22.

[0070] The lower end of the water collection pipe 22 in front of the pile is movably connected to the sand collection trough 23 in front of the pile. For example, it can be connected by rotating screws and nuts, which facilitates the flexible movement of the sand collection trough 23 in front of the pile and decelerates and promotes siltation according to the direction of sand waves and water flow.

[0071] Please refer to the following at the same time Figure 5 and Figure 6 ,in, Figure 5 This is a schematic diagram of the structure of the sand collection trough in front of the pile in one direction in one embodiment of the present invention. Figure 6This is a schematic diagram of the structure of the sand collection trough in front of the pile in another direction in one embodiment of the present invention.

[0072] In some embodiments, the pre-pile sand collection trough 23 includes two opposing first connecting plates 231, a second connecting plate 232 connecting the two first connecting plates 231, a plurality of rods 233 disposed between the two first connecting plates 231, and a plurality of biomimetic grasses 234 arranged on the rods 233. The second connecting plate 232 is movably connected to the pre-pile water collection pipe 22. There are gaps between the plurality of rods 233. The rods 233 divide the pre-pile sand collection trough 23 into an upper siltation layer 235 and a lower sand-passing layer 236.

[0073] The function of the pile front sand collection trough 23 is to slow down and promote the siltation of the silt in the water flow and to form a channel for the movement of the sand wave in front of the pier, so that the silt in the water flow and the bedload silt moving in the form of sand wave enter the pile front sand collection trough 23.

[0074] Two first connecting plates 231 and second connecting plates 232 form a frame, with no thin plate on the flow-facing side, which facilitates the entry of sand waves; the second connecting plate 232 is used to connect to the lower end of the water collection pipe 22 in front of the pile; there is no connecting plate at the bottom, so it is not affected even if unexpected scouring occurs.

[0075] Several rods 233 located between the first connecting plates 231 divide the sand collection trough 23 in front of the pile into a rectangular double-layer cavity structure, namely the upper siltation layer 235 and the lower sand passage layer 236.

[0076] Several rods 233 are arranged laterally and fixed on the first connecting plates 231 on both sides. A certain height of bionic grass 234 is evenly arranged on the rods 233 at a certain density. The function of the bionic grass 234 is to slow down and promote siltation. When the water flow and the water flow acting on the pile front water collection pipe 22 act on the bionic grass 234, its flow velocity decreases and the suspended silt will fall to the lower part of the pile front sand collection trough 23. At the same time, the bedload silt moving in the form of sand waves will enter the lower layer of the pile front sand collection trough 23 and be pushed into the pile foundation 131 together with the fallen suspended silt.

[0077] The number and size of the rods 233 and the arrangement density of the bionic grass 234 depend on the deceleration and siltation effect of the water flow acting on the water collection pipe 22 in front of the pile and moving along its surface and the opposing water flow. That is, the mud and sand moving in front of the pier as suspended matter are affected by the bionic grass 234 in the sand collection trough 23 in front of the pile, the flow velocity is reduced, and then the mud and sand fall into the silt.

[0078] In some embodiments, the second connecting plate 232 is located on the upper siltation layer 235.

[0079] The second connecting plate 232 is located only in the upper siltation layer 235, which facilitates the movement of sand waves into the interior of the pile foundation 131.

[0080] The width of the sand collection trough 23 in front of the pile, i.e., the distance between the two first connecting plates 231, is consistent with the width of the water-retaining plate 21 and the water collection pipe 22 in front of the pile. Its length is controlled at 0.5 to 1.0 times the transverse width of the pile group 13, and is roughly determined to be 2 to 3 times the pier diameter centered on the pier, depending on the influence range of the scour pit. The height is determined by the height of the upper silt-promoting layer 235 and the lower sand-passing layer 236.

[0081] In some embodiments, the height of the lower sand-passing layer 236 is greater than the height of the upper silt-promoting layer 235.

[0082] The lower sand layer 236 is higher than the upper siltation layer 235, which facilitates the passage of sand waves and provides more space for sediment to settle.

[0083] In some embodiments, the sand-collecting ring 24 includes a shell with a sand-collecting space, which is fitted onto the pile foundation 131.

[0084] The function of the sand collection ring 24 is as follows: The sand collection ring 24 is fitted on the pile foundation 131 and can change with the bed elevation. When water flows through the pile foundation 131, it can play a role in consuming the water flow and eliminating eddies, protecting the mud and sand at the bottom of the pile foundation 131 from being washed away. At the same time, when the mud and sand are pushed into the interior of the pile foundation 131, the sand collection ring 24 will retain the pushed sand waves in the sand collection space as much as possible.

[0085] The sand-collecting ring 24 is a hollow circular ring surrounding the pile foundation 131, and its number is equal to the number of pile foundations 131 in the pile group 13. The sand-collecting ring 24 is similar to the tire structure. It can be made from waste tires of suitable size, with the upper part of the tire structure removed or multiple sand inlet holes provided on the tire. The outer diameter is not greater than the pile spacing, and the inner diameter is not less than the pile foundation radius.

[0086] After the anti-scour structure 2 is installed on the high pile foundation 1, the water baffle 21 is installed at the bottom of the pile cap 12 near the pile foundation 131. The water flow formed on the pile cap 12 and the water flow on the front surface will no longer enter the pile foundation 131 to form an accelerated water flow. Instead, it will be blocked by the water baffle 21 and form a water flow or part of the water flow on the water baffle 21 to the sides and rear. The water flow to the sides has a relatively small impact on scour, but the water flow formed will have a significant impact on scour, especially the scour of mud and sand on the pile bed surface. At the same time, the water flow formed will encounter the pile front water collection pipe 22 installed at the lower end of the water baffle 21.

[0087] The top of the water collection pipe 22 in front of the pile is open, and part of the downstream water flow will enter the circular pipe 221. At the same time, the water flow entering the circular pipe 221 will overflow from several overflow holes 222 on the flow-facing surface of the circular pipe 221 at a certain flow rate, which will turbulent and slow down the impacting water flow and offset the intensity of the incoming water flow. The water flow that does not enter the circular pipe 221 will act on the inclined circular pipe 221, which can effectively diffuse the water flow and prevent it from impacting the mud surface in front of the pile as much as possible.

[0088] When the reverse water flow that impacts the pile-front water collection pipe 22 and forms on the pile-front water collection pipe 22 encounters the pile-front sand collection trough 23 installed at the lower end of the pile-front water collection pipe 22, the biomimetic grass 234 on the upper layer will effectively slow it down. Not only will the flow velocity and intensity decrease, but the suspended sediment carried by the water flow will also settle on the upper layer of the pile-front sand collection trough 23. The biomimetic grass 234 structure can not only weaken the reverse water flow formed on the pile-front water collection pipe 22, but also slow down the incoming water flow and promote sedimentation, thereby maximizing the reduction of the intensity of the water flow in front of the pile and the settling of suspended sediment in front of the pile. At the same time, the bedload sediment moving in the form of sand waves in front of the pile will be pushed into the pile foundation 131 along with the suspended sediment settling in the pile-front sand collection trough 23.

[0089] When the mud and sand pushed into the pile foundation 131 encounter the sand collection ring 24 installed on the pile foundation 131, the mud and sand will remain in the sand collection ring 24 as much as possible.

[0090] As described above, the embodiments of this application utilize the pile front water retaining plate 21, pile front water collection pipe 22, pile front sand collection trough 23, and sand collection guard ring 24 to exert a progressive and mutually combined effect of turbulence, siltation promotion, and scour prevention, actively replenishing sediment to ensure that the original bed surface sediment inside the pile foundation is not scoured away as much as possible.

[0091] In the description of this application, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the method 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 application. Unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0092] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0093] The above are merely specific embodiments of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. An anti-scour structure for a high-pile cap foundation of a bridge, characterized in that, the high-pile cap foundation (1) comprises a cap (12) and a pile group (13) connected with the cap (12), the pile group (13) comprising a plurality of pile foundations (131); the anti-scour structure (2) comprises: a front-pile water baffle (21) for being connected with the cap (12), the front-pile water baffle (21) facing a flow-approaching side of the cap (12); a front-pile water collecting pipe (22) fixedly connected with the front-pile water baffle (21); a front-pile sand collecting groove (23) movably connected with the front-pile water collecting pipe (22); and a sand collecting guard ring (24) for being sleeved on the pile foundation (131).

2. The scour protection structure for a high-pile cap foundation of a bridge according to claim 1, characterized in that, The front-pile water baffle (21) has a spacing with the pile foundation (131).

3. The scour protection structure for a high-pile cap foundation of a bridge according to claim 1, characterized in that, The front-pile water collecting pipe (22) comprises a plurality of circular pipes (221) connected with each other, the top end of the circular pipe (221) being open, and a plurality of overflow holes (222) being arranged on the flow-approaching side of the circular pipe (221).

4. The scour protection structure for a high-pile cap foundation of a bridge according to claim 3, characterized in that, There is no gap between the plurality of circular pipes (221).

5. The scour protection structure for a high-pile cap foundation of a bridge according to claim 3, characterized in that, The overflow holes (222) are of the same size, or the overflow holes (222) close to the front-pile water baffle (21) are smaller than the overflow holes (222) away from the front-pile water baffle (21).

6. The scour protection structure for a high-pile cap foundation of a bridge according to claim 1, characterized in that, The front-pile water collecting pipe (22) has an included angle with the pile foundation (131).

7. The scour protection structure for a high-pile cap foundation of a bridge according to claim 1, characterized in that, The front-pile sand collecting groove (23) comprises two oppositely arranged first connecting plates (231), a second connecting plate (232) connecting the two first connecting plates (231), a plurality of rod members (233) arranged between the two first connecting plates (231), and a plurality of bionic grasses (234) arranged on the rod members (233), the second connecting plate (232) being movably connected with the front-pile water collecting pipe (22), the plurality of rod members (233) having gaps therebetween, and the rod members (233) dividing the front-pile sand collecting groove (23) into an upper silt-promoting layer (235) and a lower sand-passing layer (236).

8. The scour protection structure for a high-pile cap foundation of a bridge according to claim 7, characterized in that, The second connecting plate (232) is located in the upper silt-promoting layer (235).

9. The scour protection structure for a high-pile cap foundation of a bridge according to claim 7, wherein The height of the lower sand-passing layer (236) is greater than that of the upper silt-promoting layer (235).

10. The scour protection structure for a high-pile cap foundation of a bridge according to any one of claims 1 to 9, characterized in that, The sand collecting guard ring (24) comprises a shell having a sand collecting space, the shell being sleeved on the pile foundation (131).

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