A silt and mucky coast bottom protection structure and a method for embedding the same

Abstract

The present application relates to the technical field of coast protection revetment, in particular to a silt and muck coast bottom protection structure and embedding method thereof, comprising a dike top concrete pavement and a dike top wave protection wall, the dike top wave protection wall is provided with a plurality of levels of revetments with gradually decreasing inclination along the extension direction, the bottom of the plurality of levels of revetments extends to a shore slope bottom protection, the shore slope bottom protection comprises vertically downward poured sheet piles, top beams and concrete cap beams, a plurality of vertical anchor bars are arranged between the concrete cap beams and the top beams, the dike foot of one side of the top beam is paved with block stone filling to form a first block stone layer, a layer of water permeable geotextile is paved on the first block stone layer, block stone with a weight greater than 70 Kg is paved on the water permeable geotextile to form a second block stone layer, a plurality of layers of special-shaped wave dissipation concrete blocks for dissipating wave scour on the slope foot are paved above the second block stone layer, the cyclic impact force of the wave is buffered in the three-dimensional direction, and a plurality of drainage pipes are arranged along the transverse direction between the top beams and the block stone layers. The cyclic scouring of the wave is greatly slowed down, the silt is less scoured, and the development of suspended pits is avoided.

Description

Technical Field

[0001] This invention relates to the field of coastal protection and slope protection technology, specifically to a silty and muddy coastal protection structure and its embedding method. Background Technology

[0002] According to on-site investigations, the coastal areas are located on erosive coastlines. During the period when the Yellow River diverted into the Huai River and flowed into the sea, the area rapidly silted up. After the Yellow River returned north, the massive sand source was cut off. The fine particles of silt and mud, along with the turbulent waves, carried the surface soil, forming suspended mud, which was carried away by the wave currents. Over a long period of time, the beach surface was continuously eroded by neap tides or storm surges, forming deep and shallow gullies. The amount of erosion has long exceeded the amount of siltation, and the coastline has been retreating year by year. Moreover, the mud and sand at the foot of the slopes have been continuously scourd out, resulting in suspended pits.

[0003] Under the long-term action of the wave's own cyclic dynamic load, the silt and mud are uneven in hardness and have large settlement differences. Traditional precast slope protection will develop misalignment, cracking, lateral flow under compression, outward bulging and heaving of the dike toe, and outward sliding and instability of the overall slope, resulting in severe seabed erosion and shoreline retreat.

[0004] In recent years, extreme weather conditions have increased, intensifying the wave dynamics experienced by seawalls. The seawall slopes and bottom protection along the coast have suffered varying degrees of damage, with some sections lacking bottom protection. This damage exposes the subgrade and core of the seawall, making it vulnerable to direct erosion by waves and currents, thus posing a risk of further damage. Furthermore, the concrete slab slope protection has already suffered extensive damage and displacement, with some sections exhibiting overall instability. This significantly weakens the seawall's protective function for the downstream shoreline and the main seawall, posing a substantial safety hazard. Summary of the Invention

[0005] The purpose of this invention is to provide a silty and muddy coastal protection structure and its embedding method to solve the problems mentioned in the background art. This invention achieves multi-stage energy dissipation through the setting of the shore slope protection; it has the advantages of dispersing water flow, eliminating concentrated jet scouring of silty and muddy slope toe, and effectively preventing the development of eddy current erosion pits.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a silty and muddy coastal protection structure, comprising a concrete pavement on the top of the dike, a wave-breaking wall on the edge of the concrete pavement near the water area, the wave-breaking wall having a multi-level slope with gradually decreasing inclination along its extension direction, the bottom of the multi-level slope extending to the shore slope protection, the shore slope protection including vertically poured sheet piles, a top beam on the top of the sheet piles, a concrete cap beam above the top beam, and several vertical anchor bars connecting the concrete cap beam and the top beam, the dike toe on one side of the top beam being filled and leveled with rubble to form the first rubble layer, a layer of permeable geotextile laid on the first rubble layer, and rubble weighing more than 70 kg laid on the permeable geotextile to an elevation of 1.1 m-1.2 m to form the second rubble layer, and a multi-layer irregularly shaped wave-dissipating concrete block for dissipating wave erosion of the slope toe laid on top of the second rubble layer, and several drainage pipes arranged horizontally between the top beam and the rubble layer.

[0007] As a further embodiment of the present invention, the irregular wave-dissipating concrete block includes a wave-dissipating concrete body integrally cast. The water-facing surface of the wave-dissipating concrete body is provided with a concave buffer trough. The rear part of the buffer trough is provided with a hollow large-diameter wave-dissipating through hole. The rear wall of the large-diameter wave-dissipating through hole is provided with a diversion hole extending to the back water surface. The diversion hole is connected to the large-diameter wave-dissipating through hole.

[0008] As a further embodiment of the present invention, the bottom of the wave-damping concrete body is provided with a concave arc groove that runs through the front and back, and the two sides of the concave arc groove are symmetrically provided with vertically interlocking bottom teeth, the bottom teeth including multiple trapezoidal grooves arranged in an equidistant array.

[0009] As a further embodiment of the present invention, the top of the wave-dissipating concrete body is provided with a trapezoidal beam that is perpendicularly embedded in each row of trapezoidal grooves. The two ends of the trapezoidal beam are flush with the two sides of the wave-dissipating concrete body. The trapezoidal beam is partially or completely overlapped with the upper opening of the buffer trough and the upper opening of the large-diameter wave-dissipating through hole, respectively.

[0010] As a further embodiment of the present invention, the two side walls of the wave-damping concrete body are provided with interlocking protrusions. The interlocking protrusions include a first protrusion on one side wall and a second protrusion on the other side wall. The contact surfaces of the first and second protrusions with the side walls are convex arc surfaces. The convex arc surfaces are in line contact with the side walls and form a vertical triangular arc hole after mating. Waves are diverted and broken up by turbulence between the two wave-damping concrete bodies, thereby weakening the positive impact pressure.

[0011] As a further embodiment of the present invention, the wave-dissipating concrete body is provided with two sets of transverse turbulence holes along the block from the water-facing side to the back-water side. The upper set of transverse turbulence holes includes two first turbulence holes symmetrically arranged along the central axis, and the cross-section of the first turbulence holes is fan-shaped. The lower set of transverse turbulence holes includes two second turbulence holes symmetrically arranged along the central axis, and the cross-section of the second turbulence holes is long groove.

[0012] As a further embodiment of the present invention, the multi-level slope protection includes a primary slope protection and a secondary slope protection arranged from top to bottom, with a wave-breaking wall set on the top of the primary slope protection, and a wave-dissipating platform provided between the primary slope protection and the secondary slope protection. The inclination angle of the primary slope protection is smaller than that of the secondary slope protection, and the slope length of the primary slope protection is greater than that of the secondary slope protection. The first-level slope protection includes trough block slope protection, with C40 concrete poured into the trough to form a concrete leveling layer, and a horizontal fence laid on the top surface along the length direction. The fence is provided with interlocking grooves at equal intervals along the length direction, and straight lines are arranged in each row of interlocking grooves and longitudinal fences are provided. Secondary slope protection includes upper trench block slope protection; The wave-dissipating platform includes a concrete wave-dissipating sill at the outer edge and plain concrete anchored to the inner side of the outer edge.

[0013] As a further embodiment of the present invention, the method for embedding a silty mud coastal revetment structure includes the following steps: S1: Vertically pour sheet piles downwards for slope protection, with anchor bars exposed at the top of the sheet piles, then pour the anchor top beam, and pour a concrete cap beam above the top beam through vertical anchor bars; S2: Several drainage pipes are arranged horizontally between the top beam and the rubble layer, with each drainage pipe spaced equidistantly at intervals of 1m-1.2m; S3: After the stone blocks are laid and leveled at the foot of the embankment, the first layer of stone blocks is formed; S4: Lay a layer of 230g / m² permeable geotextile on the first stone layer; S5: Lay stones weighing more than 70 kg on the permeable geotextile to an elevation of 1.1 m-1.2 m to form a second stone layer; S6: The second stone layer has a smooth, dry-laid, multi-layered irregularly shaped wave-damping concrete block.

[0014] As a further embodiment of the present invention, in the method for embedding a silty and muddy coastal protection structure, in step 6, the buffer trough of the irregular wave-dissipating concrete block is set in the water-facing direction, the bottom teeth of the first wave-dissipating concrete body are embedded downward into the second stone layer, the second convex edge of the side wall of the second wave-dissipating concrete body is interlocked with the second convex edge of the side wall of the first wave-dissipating concrete body, and the first row is laid in sequence. The wave-dissipating concrete bodies of the second row are set facing each other front to back, and the water-facing surface of the second row of wave-dissipating concrete is connected to the back surface of the first row of wave-dissipating concrete, thus forming the first layer of irregular wave-dissipating concrete blocks.

[0015] As a further embodiment of the present invention, in step 6, the trapezoidal beam at the top of the first layer of irregularly shaped wave-damping concrete blocks is engaged with the bottom teeth of the second layer in a one-to-one correspondence, and multiple layers of irregularly shaped wave-damping concrete blocks are laid in sequence.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention includes a concrete pavement on the top of the dike, and a wave-breaking wall on the top of the dike is provided along the edge of the concrete pavement near the water area. The wave-breaking wall on the top of the dike is provided with a multi-level slope with gradually decreasing inclination along the extension direction. The bottom of the multi-level slope extends to the bottom slope protection. The bottom slope protection includes vertically poured sheet piles, which are rigid load-bearing components with large load-bearing capacity, forming deep anchorage constraints. The continuous horizontal load of waves is offset by the lateral resistance of the deep soil, preventing the overall outward displacement and instability of the slope protection.

[0017] The sheet pile is topped with a top beam, and a concrete cap beam is placed above the top beam. Several vertical anchor bars are connected between the concrete cap beam and the top beam, which strengthens the vertical load and improves the resistance to overturning and sliding. The concrete cap beam shares the horizontal wave load with the sheet pile, resulting in a more even load distribution and eliminating stress concentration in the sheet pile.

[0018] After the first layer of riprap is laid and leveled at the toe of the embankment on one side of the top beam, a layer of permeable geotextile is laid on top of the first layer. Then, riprap weighing more than 70 kg is laid on top of the permeable geotextile to an elevation of 1.1m-1.2m, forming the second layer of riprap. Above the second layer, multi-layered irregularly shaped wave-dissipating concrete blocks are laid to dissipate wave erosion at the toe of the slope, buffering the cyclical impact of waves in three dimensions. Several drainage pipes are arranged laterally between the top beam and the riprap layer. In conjunction with these drainage pipes, the continuous erosion by long-term neap tides or storm surges is greatly reduced. The erosion of sediment at the toe of the slope is minimal, preventing the erosion volume from exceeding the sediment deposition volume over a long period. The coastline remains stable, and the sediment at the toe of the slope is firmly anchored, minimizing the formation of suspended depressions. Other advantages include: (1) The irregularly shaped wave-dissipating concrete block buffer trough is connected to the large-diameter wave-dissipating through hole and the diversion hole, and the diversion hole and the large-diameter wave-dissipating through hole are interconnected. After lateral energy dissipation, the vertical instantaneous impact is transformed into oblique shear flow. The wave cannot form a complete reflected wave, and the water is continuously discharged along the diversion hole, consuming the internal energy of the water. The fine water flow greatly reduces the impact force, reduces the wave velocity, and alleviates the erosion of the silt slope toe. It also realizes the continuous emptying of the large-diameter wave-dissipating through hole, and maintains the cavity buffer space when the next wave enters, so that the low-velocity water flow cannot stir up the surface.

[0019] (2) The bottom of the wave-dissipating concrete body is provided with a concave arc groove that runs through the front and back. On both sides of the concave arc groove, there are vertically interlocking bottom teeth and trapezoidal beams that fit together. Under the impact of circulating wave energy, a buffer protective wall is formed, and the energy of the water body is weakened layer by layer.

[0020] (3) The two side walls of the wave-dissipating concrete body are provided with interlocking protrusions. The convex arc surface and the side surface are in line contact, forming a vertical triangular arc hole after fitting. Waves are diverted and broken up by turbulence between the two wave-dissipating concrete bodies, thus weakening the positive impact pressure. This further buffers the kinetic energy of the water body.

[0021] (4) By embedding the silty and muddy coastal protection structure, multi-stage energy dissipation is achieved; the water flow is dispersed, and there is no concentrated jet scouring of the silty and muddy slope foot, effectively preventing the development of eddy current erosion pits. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall assembly structure of the present invention; Figure 2 This is a schematic diagram of the cross-sectional structure of the bank slope protection of the present invention; Figure 3 This is a schematic diagram of the overall structure of the irregularly shaped wave-damping concrete block of the present invention; Figure 4 This is a schematic diagram of the second convex ridge structure of the present invention; Figure 5 This is a schematic diagram of the large-diameter wave-damping through-hole and flow-diverting hole structure of the present invention; Figure 6 This is a schematic diagram of the irregularly shaped wave-damping concrete block stacking structure of the present invention; Figure 7 This is a top view of the irregularly shaped wave-damping concrete block of the present invention.

[0023] In the diagram: 1-bank slope protection, 101-first stone layer, 102-permeable geotextile, 103-second stone layer, 104-irregularly shaped wave-dissipating concrete block, 141-concave arc groove, 142-bottom embedded tooth, 143-first convex ridge, 144-trapezoidal beam, 145-first disturbance hole, 146-buffer trough, 147-second disturbance hole, 148-upper second convex ridge, 149-large diameter wave-dissipating through hole, 105-diversion hole, 106-vertical triangular arc hole, 2-sheet pile, 201-top beam, 202-concrete cap beam, 3-secondary slope protection, 301-longitudinal fence, 302-transverse fence, 4-wave-dissipating platform, 5-primary slope protection, 6-breakwall on top of the dike, 7-drainage pipe. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example 1

[0025] Please see the appendix Figure 1 -Appendix Figure 2A silty and muddy coastal protection structure includes a concrete pavement on the top of the seawall. A breakwater wall 6 is provided on the edge of the concrete pavement near the water area. The breakwater wall has a multi-level slope with gradually decreasing inclination along its extension direction. The multi-level slope includes a first-level slope 5 and a second-level slope 3 set from top to bottom. The breakwater wall is set on the top of the first-level slope. After the waves act on the seawall, they climb along the platform and slope, deforming and becoming steep. The high-speed water tongue formed by some large waves in the irregular wave train impacts the wave-facing side of the breakwater wall. The breakwater wall's reverse arc throws most of the water back to the wave-facing side. At the same time, due to the concentrated wave energy at the reverse arc, the breakwater wall itself is also subjected to a large wave force. Under the action of large waves in the irregular wave train, the breakwater wall experiences significant vibration and is supported by the land behind it.

[0026] The first-level slope protection 5 includes a trough block slope protection, with C40 concrete poured into the trough to form a concrete leveling layer, and a horizontal fence 302 laid on the top surface along the length direction. The fence is provided with interlocking grooves at equal intervals along the length direction, and straight lines are arranged in each row of interlocking grooves and longitudinal fences 301 are provided. A wave-dissipating platform 4 is installed between the primary slope protection 5 and the secondary slope protection 3. The wave-dissipating platform includes a concrete wave-dissipating sill at its outer edge, and plain concrete anchored to the inner side of the outer edge, with an elevation of 4.2m. The secondary slope protection includes the upper trough block slope protection; the inclination angle of the primary slope protection is smaller than that of the secondary slope protection, and the slope length of the primary slope protection is greater than that of the secondary slope protection; the slope ratio of the primary slope protection is 1:3, and the slope ratio of the secondary slope protection is 1:4.

[0027] The bottom of the first-level slope protection extends to the bank slope protection 1. The bank slope protection includes sheet piles 2 poured vertically downwards. A top beam 201 is provided on the top of the sheet piles. A concrete cap beam 202 is provided above the top beam. Several vertical anchor bars are provided between the concrete cap beam and the top beam. The elevation of the concrete cap beam is 1.2m.

[0028] After the riprap is laid and leveled on one side of the top beam, the first riprap layer 101 is formed. A layer of permeable geotextile 102 is laid on the first riprap layer. Ripples weighing more than 70 kg are laid on the permeable geotextile to an elevation of 1.1 m-1.2 m to form the second riprap layer 103. On the second riprap layer, multi-layer irregularly shaped wave-dissipating concrete blocks 104 are laid to dissipate wave erosion on the slope toe. The multi-layer irregularly shaped wave-dissipating concrete blocks are laid to a height of 3.6 m. The irregularly shaped wave-dissipating concrete blocks of the first riprap layer are concrete blocks with a length x width x height of 2 m x 1.2 m x 0.3 m and a rough surface.

[0029] Please see the appendix Figure 3 -Appendix Figure 5The irregularly shaped wave-dissipating concrete block includes an integrally cast wave-dissipating concrete body. The water-facing surface of the wave-dissipating concrete body is provided with a concave buffer trough 146, which accommodates the seawater that rushes in instantaneously, prolonging the wave load action time. At the same time, it changes the direction of water flow, turbulent flow consumes energy, and under the same water energy, the load action time becomes longer, the instantaneous impact force decreases, the kinetic energy is weakened, and the wave rise is reduced.

[0030] The bottom of the wave-damping concrete structure is provided with a concave arc groove 141 that runs through the front and back. Waves that continue to flow forward continue to flow backward along the concave arc groove. As the waves continue to flow in the concave arc groove, their flow velocity is reduced, further weakening their kinetic energy.

[0031] The rear of the buffer trough is equipped with a hollow large-diameter wave-dissipating through-hole 149. After passing through the concave arc groove, the water flows vertically into the large-diameter wave-dissipating through-hole. The water body forms a periodic rise and fall oscillation in the vertical direction. After the impact pressure is distributed, the impact force decays rapidly.

[0032] The rear wall of the large-diameter wave-dissipating through-hole is provided with a diversion hole 105 extending to the backwater surface, which is interconnected with the large-diameter wave-dissipating through-hole. When kinetic water fills the cavity of the large-diameter wave-dissipating through-hole, the continuously flowing water is constrained by the hole wall and cannot drain quickly. This can cause impact displacement of the wave-dissipating concrete structure.

[0033] The water in the large-diameter wave-dissipating through-hole is guided backward along the diversion hole. The diversion hole transforms the vertical instantaneous impact into an oblique shear flow. The wave cannot form a complete reflected wave, and the water is continuously discharged along the diversion hole, consuming the internal energy of the water. The fine water flow greatly reduces the impact force, reduces the wave velocity, and alleviates the erosion of the silt slope foot.

[0034] The large-diameter wave-dissipating through-hole is continuously vented, maintaining a cavity buffer space when the next wave enters, so that low-velocity water flow cannot stir up the surface.

[0035] Please see the appendix Figure 6 -Appendix Figure 7 When two or more wave-damping concrete structures are joined together, they are constrained in the longitudinal and transverse directions to prevent displacement.

[0036] The wave-damping concrete structure is laid out on a single plane, with sections laid in a continuous, interlocking pattern. Depending on the actual wave conditions, irregularly shaped wave-damping concrete blocks, ranging from 10 to 15 meters wide, are used.

[0037] The wave-damping concrete body has interlocking protrusions on its two side walls. These interlocking protrusions include a first protrusion 143 on one side wall and a second protrusion 148 on the other side wall. The contact surfaces of the first and second protrusions with the side walls are convex arc surfaces, forming a line contact with the side walls. After mating, they form vertical triangular arc holes 106. The function of these triangular arc holes is the same as that of the large-diameter wave-damping through holes: vertically converting the kinetic energy of the water into its internal energy, reducing the impact of the water on silt and sediment, and simultaneously reducing the rearward displacement of the wave-damping concrete body. Waves are diverted and broken up by turbulence between the two wave-damping concrete bodies, thus weakening the positive impact pressure. Example 2

[0038] The wave-dissipating concrete blocks are laid out in a continuous, horizontal and vertical plane on the same plane. However, based on the actual energy of the waves and crests, a single layer is insufficient to dissipate the wave energy, and irregularly shaped wave-dissipating concrete blocks are easily destroyed by the waves. Therefore, multiple layers of irregularly shaped wave-dissipating concrete blocks need to be laid vertically.

[0039] The upper concave arc groove of the wave-damping concrete body is symmetrically provided with vertically interlocking bottom teeth 142 on both sides, and the bottom teeth include two trapezoidal grooves arranged at equal intervals.

[0040] The top of the wave-damping concrete main body is provided with trapezoidal beams 144 that are perpendicularly embedded in each row of trapezoidal slots, and the two ends of the trapezoidal beams are flush with the two sides of the wave-damping concrete main body. The bottom teeth of the upper wave-dissipating concrete structure are symmetrically arranged along both ends of the trapezoidal beam, and the bottom teeth are perpendicularly engaged with the trapezoidal beam. The irregularly shaped wave-dissipating concrete blocks are embedded and fixed in three dimensions, forming a buffer and protective wall under the impact of circulating wave energy, and the energy of the water is weakened layer by layer.

[0041] The trapezoidal beams are partially or completely overlapped with the upper opening of the buffer sump and the upper opening of the large-diameter wave-dissipating through-hole. The trapezoidal beams do not affect the buffering performance of the upper opening of the buffer sump and the large-diameter wave-dissipating through-hole. Example 3

[0042] The wave-damping concrete body is provided with two sets of transverse turbulence holes along the block from the water-facing side to the back-water side. The upper set of transverse turbulence holes includes two first turbulence holes 145 symmetrically arranged along the central axis. The cross-section of the first turbulence hole is fan-shaped. The lower set of transverse turbulence holes includes two second turbulence holes 147 symmetrically arranged along the central axis. The cross-section of the second turbulence hole is long groove.

[0043] The upper and lower sets of transverse turbulence holes have different shapes. The water body is throttled and slowed down through the narrow channels, and the accumulated water is drained in time. Furthermore, the transverse holes buffer the impact energy of the water body, reduce the instantaneous peak water pressure, realize the pressure relief of the entire slope, and the through channel continuously achieves buffering.

[0044] Multiple drainage pipes are installed horizontally between the top beam and the rubble layer. The drainage pipes are evenly spaced, with a spacing of 1m-3m. Water that seeps into the crushed stone cushion layer is collected after being blocked by the wave-damping concrete main body and discharged to the outer beach. Example 4

[0045] The method for securing silty and muddy coastal revetment structures includes the following steps: S1: Vertically pour sheet piles 2 downwards for slope protection, with anchor bars exposed at the top of the sheet piles, and then pour anchor top beam 201. Above the top beam, pour concrete cap beam 202 through vertical anchor bars. S2: Several drainage pipes 7 are arranged horizontally between the top beam and the rubble layer, with each drainage pipe spaced equidistantly at intervals of 1m-1.2m; S3: After the embankment toe is paved with riprap and leveled, the first riprap layer 101 is formed; the first riprap layer consists of... S4: Lay a layer of 230g / m² permeable geotextile 102 on the first stone layer; S5: Lay stones weighing more than 70Kg on the permeable geotextile to an elevation of 1.1m-1.2m to form a second stone layer 103; S6: The second stone layer consists of a smooth, dry-laid multi-layer irregularly shaped wave-damping concrete block 104. The buffer trough of the irregularly shaped wave-damping concrete block is set in the water-facing direction. The bottom teeth of the first wave-damping concrete body are embedded downwards into the second stone layer. The second protruding edge of the side wall of the second wave-damping concrete body interlocks with the second protruding edge of the side wall of the first wave-damping concrete body. The first row is laid in sequence. The wave-damping concrete bodies of the second row are set facing each other front to back. The water-facing surface of the second row of wave-damping concrete is connected to the backwater surface of the first row of wave-damping concrete. The first layer of irregularly shaped wave-damping concrete blocks is thus formed.

[0046] The trapezoidal beam at the top of the first layer of irregularly shaped wave-damping concrete blocks is matched and engaged with the bottom teeth of the second layer, and multiple layers of irregularly shaped wave-damping concrete blocks are laid in sequence. Example 5

[0047] This embodiment is an experimental embodiment, demonstrating the optimization results of this structure through experiments. The research content includes: (1) Select an appropriate model scale to simulate the shoreline, beach protection projects, seawalls, etc. in the project area.

[0048] (2) Through wave cross-section physical model test and wave local overall physical model test, beach scour test under different water levels and wave conditions was carried out to measure the development of scour pits and the maximum scour depth.

[0049] (3) Through wave cross-section physical model test and wave local overall physical model test, the stability of each part of the beach protection and reinforcement project under the action of wave dynamic conditions at different beach elevations is observed to verify the rationality of the design scheme.

[0050] (4) Based on the experimental phenomena and results, propose corresponding optimizations to the design scheme of the beach reinforcement project and conduct further experiments to demonstrate its effectiveness.

[0051] Irregular waves will be used for the experiment, with the JONSWAP spectrum adopted. The model should be designed and constructed according to the specific requirements of the "Wave Hydrodynamic Model Test" section of the "Technical Specification for Simulation Test of Water Transport Engineering" (JTS / T 231-2021), including basic data collection, model calibration, and wave motion testing. The quantity and method of the revetment deployment should comply with the relevant provisions of the current industry standard "Design Code for Breakwaters and Revetments" (JTS 154-2018). The overall requirements for the experimental research must meet current specifications, standards, and requirements, including but not limited to "Technical Specification for Simulation Test of Water Transport Engineering" JTS / T 231-2021, "Hydrological Specification for Ports and Waterways" JTS 145-2015 (2022 Edition), and "Design Code for Breakwaters and Revetments" JTS-154-2018. Before the formal test, wavelets will be applied continuously for a period of time. Each test group should be repeated at least three times. If the results of the three tests differ significantly, the number of repetitions should be increased. Based on the results of the model test, the cross-sectional structure was modified and improved as necessary.

[0052] Both the scale-based wave cross-section physical model test and the local / overall wave physical model test complied with the relevant provisions of the "Technical Specification for Simulation Tests of Water Transport Engineering," employing a normal distribution model and designed according to the Froude number similarity law. The geometric scale of the model was 1:15, and the scales of various physical quantities are as follows: Geometric scale: Lr = 1:15, Time scale: Tr = Lr¹ / ² Weight scale: Gr = Lr3, unit width flow rate scale: qr = Lr3 / 2.

[0053] When conducting wave model tests, the wave propagation speed, water particle motion, wave refraction, and wave breaking conditions in the model must be similar to those of the prototype. The scales that satisfy the above conditions for similarity are as follows: Similar wave speeds: ; Wave periods are similar: ; Similarities in the movement of water particles: ; Wave refraction is similar: ; As can be seen from the above, since both the wave cross-section physical model test and the wave local overall physical model test adopted the normal model, This ensures that the wave motions are similar.

[0054] Waves are simulated according to the gravity similarity criterion, and the irregular wave spectrum is taken from the JONSWAP spectrum.

[0055] The characteristic wave elements, converted to the model scale, are input into the computer to generate wave-generating signals, controlling the wave generator to produce corresponding regular and irregular wave sequences. Each test group contains no fewer than 1000 irregular waves, and each test group is repeated three times. The errors between the simulated wave height and period values ​​and the design values ​​in the model tests are controlled within ±5%.

[0056] The spectral density function is: ; In the formula, α is a dimensionless constant; fp is the peak frequency; γ is the peak elevation factor, which is 3.3; σ is the peak shape parameter, which is 0.07 when f ≤ fp and 0.09 when f > fp.

[0057] Sediment simulation: The purpose of this test is to simulate and predict the scouring situation in front of the dam. Therefore, the test sediment must meet the initiation similarity under wave action.

[0058] Due to the small particle size of the bottom sediment and the strong cohesion between particles, the eroded soil samples do not move as individual particles, and the scour depth differs from that of non-cohesive sand. Considering the long-term safety of the project, the cohesion of the silty clay layer (14.5 kPa) was used as the test parameter.

[0059] The relationship between the erosion-resistant equivalent particle size and cohesion of cohesive soil is as follows: ; In the formula, c is the cohesion (kPa) and D is the equivalent particle size (m).

[0060] The equivalent particle size for impact resistance of the substrate at the site, calculated using the above formula, is 2.86 mm. γs=2.65t / m3 Initiating wave height under wave action: ; After comparison and selection, this experiment used a median particle size D50 of 0.28 mm. The model sand with γs=2.65t / m3 simulated erosion-resistant equivalent particle size of 2.86mm and γs=2.65t / m3. Since the model is a normal model, the experimental geometric scale l = 1:15 and the starting wave height scale lH = 1:15.

[0061] The ratio of the initiation bottom velocity of the model sand to the prototype sand under wave action was 1:14.5, which is close to 1:15, indicating that the initiation similarity of the sediment was good.

[0062] The following table compares the similarity of the prototype sand (equivalent erosion resistance particle size) and the model sand initiation:

[0063] Simulation of test cross-section: (1) Wave cross section physical model test All parts of the test section maintained geometric similarity to the prototype, and all structural components were scaled down to the required size, with a model error not exceeding 1 mm. Irregularly shaped wave-damping concrete blocks and other components were constructed using counterweight mortar to ensure weight similarity. The bottom retaining riprap and core fill stones were rigorously selected to maintain weight similarity to the prototype.

[0064] (2) Wave local and overall physical model test The test section, buildings, and other components in the model maintain geometric similarity to the prototype. All structural parts are fabricated at scale reduction, with a model error not exceeding 1mm. Irregularly shaped wave-damping concrete blocks and other parts are made using counterweight mortar to ensure weight similarity. The bottom retaining boulders and dam core fill stones are strictly selected to maintain weight similarity to the prototype.

[0065] The model's planar dimensions and the buildings (including terrain) conform to the geometric length scale. The elevation is determined using the cross-section method, with deviations controlled within ±1mm; the building elevation deviations are controlled within ±1%, in accordance with the "Technical Specifications for Simulation Testing of Water Transport Engineering".

[0066] Test water level: The test will be conducted at the design tide level of 4.02m (a 50-year high tide level), with an additional supplementary water level of 3.00m to verify the stability of the project. The specific test water levels are as follows: Test water level 1: 4.02m (50-year high tide level); Test water level 2: 3.00m.

[0067] Under test water level 1 and corresponding wave action, the overtopping volume measured at the crest of the main seawall was 0.002 m. 3 / (m*s); Under the test water level 2 and the corresponding wave action, only a few waves reached the top of the dike, and no overtopping waves were measured.

[0068] (1) Results of the overflight test The results of the wave height test are as follows:

[0069] (2) Results of stability test The stability test results are as follows:

[0070]

[0071] The stability test phenomena and test results of the wave-breaking wall on the top of the dike, the first-level slope protection, the second-level slope protection, and the irregularly shaped wave-dissipating concrete blocks all meet the stability requirements under wave action.

[0072] The 0.9m irregular wave-dissipating concrete block bottom protection was increased to 1.4m irregular wave-dissipating concrete block bottom protection. The block size and weight increased, but no displacement occurred under test water level one, test water level two and corresponding wave action, meeting the stability requirements under wave action.

[0073] Under test water level 1, test water level 2, and corresponding wave action, individual bottom protection stones rolled, but the whole structure remained stable, meeting the stability requirements under wave action.

[0074] The bottom of the seawall is protected by 1.4m irregularly shaped wave-dissipating concrete blocks, which further improves the stability of the seawall toe.

[0075] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the scope of the invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0076] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A silty and muddy coastal protection structure, comprising a concrete pavement on the top of the dike, wherein a wave-breaking wall (6) is provided along the edge of the concrete pavement on the side closest to the water, characterized in that: The wave-breaking wall on the top of the dike is provided with a multi-level slope with gradually decreasing inclination along the extension direction. The bottom of the multi-level slope extends to the bottom slope protection (1). The bottom slope protection includes sheet piles (2) poured vertically downward. A top beam (201) is provided on the top of the sheet pile. A concrete cap beam (202) is provided above the top beam. Several vertical anchor bars are provided between the concrete cap beam and the top beam. After the dike foot on one side of the top beam is filled with rubble and leveled, the first rubble layer (101) is formed. A layer of permeable geotextile (102) is laid on the first rubble layer. Rubble weighing more than 70Kg is laid on the permeable geotextile to an elevation of 1.1m-1.2m to form the second rubble layer (103). A multi-layer irregular wave-dissipating concrete block (104) for dissipating the scouring of the slope foot by waves is laid on the second rubble layer. Several drainage pipes (7) are arranged horizontally between the top beam and the rubble layer.

2. The silty mud coastal revetment structure according to claim 1, characterized in that: The irregular wave-dissipating concrete block (104) includes an integrally cast wave-dissipating concrete body. The water-facing surface of the wave-dissipating concrete body is provided with a concave buffer trough (146). The rear part of the buffer trough is provided with a hollow large-diameter wave-dissipating through hole (149). The rear wall of the large-diameter wave-dissipating through hole is provided with a diversion hole (105) extending to the back water surface. The diversion hole is connected to the large-diameter wave-dissipating through hole.

3. The silty mud coastal revetment structure according to claim 2, characterized in that: The bottom of the wave-damping concrete body is provided with a concave arc groove (141) that runs through the front and back, and the two sides of the concave arc groove are symmetrically provided with vertically interlocking bottom teeth (142), which include multiple trapezoidal grooves arranged in an equidistant array.

4. The silty mud coastal revetment structure according to claim 3, characterized in that: The top of the wave-dissipating concrete body is provided with a trapezoidal beam (144) that is perpendicularly embedded in each row of trapezoidal grooves. The two ends of the trapezoidal beam are flush with the two sides of the wave-dissipating concrete body. The trapezoidal beam is partially or completely overlapped with the upper opening of the buffer trough and the upper opening of the large-diameter wave-dissipating through hole.

5. The silty mud coastal revetment structure according to claim 4, characterized in that: The wave-dissipating concrete body has interlocking protrusions on its two side walls. The interlocking protrusions include a first protrusion (143) on one side wall and a second protrusion (148) on the other side wall. The contact surfaces of the first and second protrusions with the side walls are convex arc surfaces. The convex arc surfaces are in line contact with the side surfaces and form a vertical triangular arc hole (106) after fitting together. Waves are diverted and broken by turbulence between the two wave-dissipating concrete bodies, thus weakening the positive impact pressure.

6. The silty mud coastal revetment structure according to claim 5, characterized in that: The wave-dissipating concrete body is provided with two sets of transverse turbulence holes along the block from the water-facing side to the back-water side. The upper set of transverse turbulence holes includes two first turbulence holes (145) symmetrically arranged along the central axis. The cross-section of the first turbulence hole is fan-shaped. The lower set of transverse turbulence holes includes two second turbulence holes (147) symmetrically arranged along the central axis. The cross-section of the second turbulence hole is a long groove.

7. The silty mud coastal revetment structure according to claim 1, characterized in that: The multi-level slope protection includes a first-level slope protection (5) and a second-level slope protection (3) set from top to bottom. The wave-breaking wall on the top of the embankment is set on the top of the first-level slope protection. A wave-dissipating platform (4) is set between the first-level slope protection and the second-level slope protection. The inclination angle of the first-level slope protection is smaller than that of the second-level slope protection, and the slope length of the first-level slope protection is greater than that of the second-level slope protection. The first-level slope protection (5) includes a trough block slope protection, in which C40 concrete is poured to form a concrete leveling layer, and a horizontal fence (302) is laid on the top surface along the length direction. The fence is provided with interlocking grooves at equal intervals along the length direction, and straight lines are arranged in each row of interlocking grooves and longitudinal fences (301) are provided. Secondary slope protection (3) includes upper trench block slope protection; The wave-dissipating platform (4) includes a concrete wave-dissipating sill on the outer edge and plain concrete anchored on the inner side of the outer edge.

8. A method for embedding a silty mud coastal revetment structure as described in claim 6 or claim 7, characterized in that, Includes the following steps: S1: Vertically pour sheet piles (2) for slope protection, with anchor bars exposed at the top of the sheet piles, and then pour the anchor top beam (201). Above the top beam, pour a concrete cap beam (202) through vertical anchor bars. S2: Several drainage pipes (7) are arranged horizontally between the top beam and the rubble layer, with each drainage pipe spaced equidistantly at intervals of 1m-1.2m; S3: After the embankment foot is paved with stones and filled and leveled, the first stone layer (101) is formed. S4: Lay a layer of 230g / m² permeable geotextile (102) on the first stone layer. S5: Lay boulders weighing more than 70 kg on the permeable geotextile to an elevation of 1.1 m-1.2 m to form a second boulder layer (103). S6: The second stone layer has a smooth, dry-laid, multi-layered irregularly shaped wave-damping concrete block (104).

9. The method for embedding a silty mud coastal revetment structure according to claim 8, characterized in that, In step 6, the buffer trough of the irregular wave-dissipating concrete block is set in the water-facing direction. The bottom teeth of the first wave-dissipating concrete body are embedded downward into the second stone layer. The second protruding edge of the side wall of the second wave-dissipating concrete body is interlocked with the second protruding edge of the side wall of the first wave-dissipating concrete body. The first row is laid in sequence. The wave-dissipating concrete bodies of the second row are set facing each other. The water-facing surface of the second row of wave-dissipating concrete is connected to the back water-facing surface of the first row of wave-dissipating concrete. The first layer of irregular wave-dissipating concrete blocks is built in sequence.

10. The method for embedding a silty mud coastal revetment structure according to claim 9, characterized in that, In step 6, the trapezoidal beam at the top of the first layer of irregularly shaped wave-damping concrete blocks is matched with the bottom teeth of the second layer, and multiple layers of irregularly shaped wave-damping concrete blocks are laid in sequence.

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