A coastal port bottom protection and anti-scour structure

Abstract

The present invention provides a coastal port bottom protection and anti-scour structure, comprising a horizontal protection unit and a vertical protection unit located below the horizontal protection unit, wherein the vertical protection unit is inserted below the mud surface, and the upper edge of the vertical protection unit is close to the mud surface, and the vertical protection unit comprises a group of protection walls or multiple groups of protection walls arranged at intervals, wherein the protection wall closest to the sea side divides the soil of the coastal port into two areas, namely a reserved scour area on the side of the protection wall facing the sea body and a stable area on the side of the protection wall facing away from the sea body. The beneficial effect of the present invention is that it adopts a two-way protection concept of horizontal protection and vertical protection, the horizontal active protection system can reduce scour, and the vertical passive protection structure system allows scour to a certain depth. The anti-scour structure of the combination of horizontal protection and vertical protection can not only protect the safety and stability of the main structure, but also reduce the frequency of scour repairs, and can also save sea use to the greatest extent. It has a simple structure, is easy to implement, and is easy to promote.

Description

Technical Field

[0001] The invention belongs to the field of hydraulic structures in coastal engineering and port engineering, and in particular relates to a coastal port bottom protection and anti-scouring structure. Background Art

[0002] Currently, traditional anti-scour bottom protection structures primarily consist of one-way horizontal structures, consisting of a geotextile laid on the original mud surface, covered with a two-piece stone inverted filter structure and bottom protection blocks. Conventional horizontal protection structures are 5-15 meters long in non-scour areas, but need to be extended to 30-50 meters in scour areas. More significantly, at the head of the breakwater, the bottom protection range can reach 200-300 meters, occupying a significant amount of sea area and not in line with the principles of economical and ecological use of the sea. Conventional horizontal protection measures are difficult to maintain in areas with severe scour. As the country's requirements for sea use policies become increasingly stringent, the limitations of conventional protection methods in areas with severe scour are becoming more pronounced, consuming both sea area and materials. Summary of the Invention

[0003] The inventive concept of this technical solution is to protect the coastal soil by combining horizontal and vertical protection units. The horizontal protection units can reduce scour, and the vertical protection units can achieve the function of reserving scour depth. One of the functions of the reserved scour depth is to ensure that the vertical protection units can be fixed in the soil. The combined horizontal and vertical protection anti-scour structure can significantly reduce the area of sea use and is an effective anti-scour structure that actively responds to national sea use policies. In addition, this combined anti-scour structure has a low demand for sand and stone raw materials. Under the current situation of strict control of sea use policies, this combined anti-scour structure is the preferred structural type.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is: a coastal port bottom protection and anti-scour structure, including a horizontal protection unit, and also including a vertical protection unit located below the horizontal protection unit, the vertical protection unit is inserted below the mud surface, the upper edge of the vertical protection unit is close to the mud surface, the vertical protection unit includes a group of protection walls or multiple groups of protection walls arranged at intervals, wherein the protection wall closest to the sea side divides the soil of the coastal port into two areas, namely, a reserved scour area on the side of the protection wall facing the sea body, allowing natural scouring of sediment to reach dynamic balance, and a stable area on the side of the protection wall facing away from the sea body, maintaining the stability of the structure, the size of the reserved scour area is determined based on the scour protection depth formula, wherein the scour protection depth formula is:

[0005]

[0006] Where a1 and a2 are scour coefficients, which are determined by experiments. If there is no experimental data, they are taken as 3.0 and 0.38 respectively; u t、u w are the shear velocity and wave bottom velocity caused by tidal current respectively; u c* is the starting velocity of seabed sediment; D is the hydraulic influence radius of water flow acting on the breakwater.

[0007] Optionally, the lower edge of the vertical protection unit is 5-30m away from the mud surface.

[0008] Optionally, the protective wall is formed by splicing together a plurality of unit bodies arranged continuously.

[0009] Optionally, the unit bodies are connected and fixed into a whole through a connector.

[0010] Optionally, the connecting body is a guide beam, and the upper end of the unit body is fixed on the guide beam.

[0011] Optionally, the groove of the guide beam is filled with sand and gravel.

[0012] Optionally, the sand and gravel material is one or a combination of sand, two-piece stone or block stone.

[0013] Optionally, the horizontal protection unit includes a geotextile, and a combination of one or more of stone blocks, sand rib soft material rows, and interlocking block soft material rows are arranged on the geotextile.

[0014] Optionally, the protection length of the horizontal protection unit is 5-50m.

[0015] The advantages and positive effects of the present invention are: the present invention proposes a two-way protection concept of a combination of horizontal protection and vertical protection. The horizontal protection unit can reduce scouring, and the vertical protection unit can allow scouring of a certain depth to occur. The anti-scouring structure of the combination of horizontal protection and vertical protection can not only protect the safety and stability of the main structure, but also reduce the frequency of scouring repairs and save sea use to the greatest extent; its structure is simple, easy to implement, and easy to promote. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the overall structure of a specific embodiment of the present invention;

[0017] Figure 2 yes Figure 1 Schematic diagram of the structure of the medium level protection unit;

[0018] Figure 3 yes Figure 1 Schematic diagram of the structure of the middle vertical protection unit;

[0019] In the figure: 1-horizontal protection unit; 1-1-geotextile filter layer; 1-2 two-stone cushion layer; 1-3 bottom protection stone; 2-vertical protection unit; 2-1-steel sheet pile; 2-2-steel guide beam; 2-3-backfill material; 3-mud surface. DETAILED DESCRIPTION

[0020] The present invention will be further described in detail below with reference to specific embodiments. It should be understood that the specific embodiments described herein are intended only to explain the present invention and are not intended to limit the present invention. In the description of the present invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inside," "outside," and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended only to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as limiting the present invention. In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can be fixedly connected, detachably connected, or integrally connected; they can be mechanically connected or electrically connected; they can be directly connected, indirectly connected through an intermediate medium, or they can be internally connected between two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood based on specific circumstances.

[0021] As shown in the figure, the present invention provides a coastal port bottom protection and anti-scour structure, including a horizontal protection unit 1 and a vertical protection unit 2, wherein the horizontal protection unit 1 is composed of two stone cushion layers 1-2 and bottom protection blocks 1-3 laid on a geotextile. The horizontal protection unit 1 is laid on the mud surface of the port coast. The horizontal protection unit 1 includes a geotextile, and a combination of one or more of blocks, sand rib soft material rows, and interlocking block soft material rows are arranged on the geotextile to protect the mud surface in the horizontal direction. The vertical protection unit 2 can be composed of one or more groups of protective walls arranged at intervals. In this embodiment, a group of protective walls is used. The example of the invention is illustrated, wherein the length of the horizontal protection unit 1 is between 5-50m, the lower edge of the protection wall extends 5-30m below the mud surface 3, and the protection wall is composed of multiple steel sheet piles, pile rows, guide beams, and steel structures or reinforced concrete structures fixedly spliced by steel guide beams. The protection wall is set in the mud surface 3 below the horizontal protection unit 1, and its side facing the sea body is a reserved scouring area. One of the functions of the reserved scouring area is to enable the protection wall to be fixed in the mud surface 3. The width and depth of the scouring area need to be determined based on theoretical calculations and preliminary simulation tests.

[0022] The formula for scour protection depth is as follows:

[0023]

[0024] Where a1 and a2 are scour coefficients, which are determined by experiments. If there is no experimental data, they can be taken as 3.0 and 0.38; u t、u w are the shear velocity and wave bottom velocity caused by tidal current respectively; u c* is the starting velocity of seabed sediment; D is the hydraulic influence radius of water flow acting on the breakwater.

[0025] The width of the scouring area is the distance from the coastline to the protective wall, and the depth is the depth of the protective wall inserted into the soil. The width and depth of the scouring area are based on the ability to firmly fix the protective wall in the soil when the soil in the scouring area reaches dynamic equilibrium after being scoured. In actual use, the depth of the soil in the scouring area should be regularly tested. When it reaches a dangerous value, that is, the soil in the scouring area is no longer sufficient to fix the protective wall in the soil after being scoured, the protective structure needs to be repaired in time to avoid greater losses.

[0026] By ensuring that the protective wall in the vertical protection unit 2 can be stably fixed in the soil, it can be ensured that the soil on the side of the protective wall facing away from the sea is in a relatively stable state and will not be lost due to scouring, thereby maximizing the relative integrity of the entire anti-scouring structure. Even if the part facing the sea needs to be repaired, the repair area can also be controlled within a smaller range.

[0027] The protective wall in this embodiment can be composed of a spliced structure of steel sheet piles 2-1, wherein the top of the steel sheet piles 2-1 is fixed on the steel guide beam 2-2, and the groove of the steel guide beam 2-2 is filled with sand and gravel to make the overall structure more stable.

[0028] The construction method of the protective structure is as follows:

[0029] First, vertical protection unit 2 was implemented. Before construction, temporary guide piles and guide beams were installed on-site to facilitate the positioning of the steel sheet piles. The processed steel sheet piles were transported to the site by barge and driven on-site using a piling vessel or a barge equipped with piling equipment. During piling, a vibrating hammer, suspended from a crane on the work vessel, drove the sheet piles individually or in groups. The steel sheet piles were vibrated down to the designed elevation one by one using a stepped method. After the steel sheet piles were driven, a diving team installed the steel guide beam 2-2 underwater. Before installing the steel guide beam 2-2, divers used high-pressure water guns to create grooves underwater, exposing the tops of the steel sheet piles for easy installation. After the steel guide beam 2-2 was installed, the trench was promptly filled with sand and gravel.

[0030] Next, horizontal protection unit 1 was implemented: After the geotextile was fabricated onshore, it was transported to the site by barge and laid using a laying vessel. The second stone cushion layer 1-2 and the bottom protection blocks 1-3 were filled by barges or transported by barges. On-site manpower and machinery were used to lay the stones during low tide.

[0031] The scour prevention structure, which combines horizontal and vertical protection, can be widely used for scour protection on artificial island walls, breakwaters, revetments, or bank slopes. The horizontal protection unit 1 reduces scour, while the vertical protection unit 2 provides a reserved scour depth. Figure 1 The dotted line in the middle and lower part represents the seabed profile line formed by scouring by seawater and the appearance of scouring pits. As can be seen from the figure, even if a certain degree of scouring pits occurs, until the scouring of sediment reaches equilibrium, according to the formula calculation and theoretical derivation, it still does not affect the stability of the anti-scouring structure of the present invention, proving that the structure is more stable than the anti-scouring structure of the prior art and has better anti-scouring pit resistance. Therefore, the anti-scouring structure of the present invention can stably and long-term play an anti-scouring role for the bottom protection of coastal ports. The combined structure of horizontal and vertical protection can reduce the amount of sand and gravel used and reduce the area of sea used. In an actual breakwater project, the use of this solution reduced the protected sea area by about 80,000 square meters. It is an effective anti-scouring structure that actively responds to the national sea use policy.

[0032] The embodiments of the present invention are described in detail above, but the contents described are only preferred embodiments of the present invention and should not be considered to limit the scope of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A coastal port bottom protection and anti-scour structure, comprising a horizontal protection unit, characterized in that: It also includes a vertical protection unit located below the horizontal protection unit, the vertical protection unit is inserted below the mud surface, the upper edge of the vertical protection unit is close to the mud surface, the vertical protection unit includes a group of protection walls or multiple groups of protection walls arranged at intervals, wherein the protection wall closest to the sea side divides the soil of the coastal port into two areas, namely a reserved scouring area on the side of the protection wall facing the sea body that allows natural scouring of sediment to reach dynamic balance, and a stable area on the side of the protection wall facing away from the sea body that maintains the stability of the structure. The size of the reserved scouring area is determined based on the scouring protection depth formula, wherein the scouring protection depth formula is: Where a1 and a2 are scour coefficients, which are determined by experiments. If there is no experimental data, they are taken as 3.0 and 0.38 respectively; u t 、u w are the shear velocity and wave bottom velocity caused by tidal current respectively; u c* is the starting velocity of seabed sediment; D is the hydraulic influence radius of water flow acting on the breakwater.

2. The coastal port bottom protection and anti-scour structure according to claim 1 is characterized by: The lower edge of the vertical protection unit is 5-30m away from the mud surface.

3. The coastal port bottom protection and anti-scour structure according to claim 2, characterized in that: The protective wall is formed by splicing a plurality of continuously arranged unit bodies.

4. The coastal port bottom protection and anti-scour structure according to claim 3, characterized in that: The unit bodies are connected and fixed into a whole through a connector.

5. The coastal port bottom protection and anti-scour structure according to claim 4, characterized in that: The connecting body is a guide beam, and the upper end of the unit body is fixed on the guide beam.

6. The coastal port bottom protection and anti-scour structure according to claim 5, characterized in that: The groove of the guide beam is filled with sand and gravel.

7. The coastal port bottom protection and anti-scour structure according to claim 6, characterized in that: The sand and gravel material is one or a combination of sand, two-piece stone or block stone.

8. The coastal port bottom protection and anti-scour structure according to claim 5, characterized in that: The guide beam is a steel structure or a reinforced concrete structure.

9. The coastal port bottom protection and anti-scour structure according to any one of claims 1 to 8, characterized in that: The horizontal protection unit comprises a geotextile, on which a combination of one or more of block stones, sand rib soft material rows, and interlocking block soft material rows is arranged.

10. The coastal port bottom protection and anti-scour structure according to claim 9, characterized in that: The protection length of the horizontal protection unit is 5-50m.

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