Ecological revetment structure of stepped box-shaped building blocks and construction method thereof

Abstract

The application discloses a stepped box-type block ecological revetment structure and a construction method thereof, and belongs to the technical field of riverbank protection. The revetment structure comprises at least one foundation unit which is laid at the bottom of a foundation pit, a plurality of box-type blocks which are arranged in a stepped and descending manner from bottom to top, and connecting pieces which are used for fixedly connecting adjacent box-type blocks; an integrated filter system is arranged behind the walls of the box-type blocks and comprises at least one geotextile and a gravel filter layer; an ecological green layer is arranged in the internal cavities of at least part of the box-type blocks; water-permeable holes are formed in the box-type blocks and are used for connecting the internal cavities with the external environment; and the internal cavities of the box-type blocks which are arranged at different height positions in the revetment structure are selectively filled with coarse aggregates or planting soil which is used for forming the ecological green layer. Through the stepped and descending arrangement of the box-type blocks and the design of the gravity center being offset to the soil direction, and in cooperation with the connecting pieces of the box-type blocks, the overall overturning resistance and sliding resistance of the revetment structure are enhanced.

Description

Technical Field

[0001] This invention relates to the field of riverbank protection technology, specifically to a stepped box-type block ecological revetment structure and its construction method. Background Technology

[0002] With the continuous advancement of river ecological management projects, traditional revetment structures can no longer meet the multiple demands of flood control, ecological restoration, and landscape beautification. Existing revetments mostly adopt gravity-type cast-in-place retaining walls, which suffer from problems such as long construction cycles, unstable quality, and poor ecological performance. They cannot achieve hydrological connectivity between the bank slope and the river channel, and are unable to provide a habitat for aquatic organisms. Some precast block revetments have defects such as insufficient structural stability, weak connections between blocks, and imperfect filtration systems, making them prone to problems such as erosion, block loosening, and bank collapse. Moreover, the construction process lacks standardization, resulting in low efficiency and making it impossible to achieve simultaneous completion of structural construction and ecological restoration.

[0003] Therefore, developing a stepped box-type block ecological revetment structure and construction method that takes into account structural stability, ecological adaptability and construction convenience has become the key to solving the above-mentioned technical problems. Summary of the Invention

[0004] (a) Technical problems to be solved

[0005] To address the shortcomings of existing technologies, this invention provides a stepped box-type block ecological revetment structure and its construction method, solving at least one technical problem mentioned in the background art.

[0006] (II) Technical Solution

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] Firstly, a stepped box-type block ecological revetment structure is provided, including:

[0009] At least one basic unit is laid at the bottom of the foundation pit, serving as the bearing benchmark for the revetment structure;

[0010] Multiple prefabricated hollow box-shaped blocks are arranged in a stepped manner from bottom to top, and adjacent box-shaped blocks are fixedly connected to each other by connectors.

[0011] An integrated reverse filtration system is installed behind the wall of the box-shaped masonry block. The reverse filtration system includes at least one layer of geotextile and a crushed stone reverse filtration layer wrapped by the geotextile.

[0012] And an ecological greening layer, which is set in the internal cavity of at least a portion of the box-shaped blocks;

[0013] The box-shaped blocks are provided with permeable holes to connect their internal cavities with the external environment; and, depending on the different height positions of the box-shaped blocks in the revetment structure, their internal cavities are selectively filled with coarse aggregate or planting soil for forming the ecological greening layer.

[0014] Preferably, the integrated reverse filtration system includes:

[0015] At least two layers of geotextile are stacked together, namely an inner geotextile and an outer geotextile, and a gravel filter layer and a bidirectional reinforced geogrid are laid between the inner geotextile and the outer geotextile; the bidirectional reinforced geogrid is laid on the gravel filter layer, and the inner geotextile is closer to the fill side than the outer geotextile.

[0016] Furthermore, the inner geotextile has multiple raised structures formed on the side surface facing the crushed stone filter layer.

[0017] Preferably, the permeable holes on the box-shaped block include:

[0018] Large-diameter permeable holes are formed on the water-facing side wall of the box-shaped block;

[0019] Medium-diameter permeable holes are formed on the back soil sidewall of the box-shaped masonry block, and the opening ratio of the medium-diameter permeable holes is lower than that of the large-diameter permeable holes.

[0020] And micro-sized permeable holes formed on the bottom wall of the box-shaped block.

[0021] Preferably, a guide pipe is pre-embedded in the large-diameter permeable hole on the water-facing sidewall, and one end of the guide pipe extends out of the outer surface of the water-facing sidewall and slopes downward; and / or, a longitudinally extending stress-dispersing rib is also provided on the back sidewall of the box-shaped block.

[0022] Preferably, at least one of the box-shaped blocks has a vertical tubular member in its internal cavity, the tubular member being filled with a functional filling material different from the internal cavity of the box-shaped block, and the tubular member having openings at both the top and bottom for water to enter and exit.

[0023] Preferably, for box-shaped blocks with internal cavities filled with coarse aggregate, the functional filling material filled in the tubular components inside is coarse sand; for box-shaped blocks with internal cavities filled with planting soil, the functional filling material filled in the tubular components inside is an absorbent material.

[0024] Preferably, in the crushed stone filter layer, the crushed stone layer adjacent to the back soil sidewall of the box-shaped masonry block has a crushed stone particle size that matches the pore size of the permeable holes on the back soil sidewall of the box-shaped masonry block at the corresponding position, so as to prevent the filling material of the internal cavity of the box-shaped masonry block from entering the crushed stone filter layer.

[0025] Preferably, a water-swellable material is incorporated into the gravel filter layer behind the wall corresponding to the box-shaped blocks used to form the ecological greening layer.

[0026] Secondly, a construction method for the stepped box-type block ecological revetment structure described in any of the above claims is also provided, comprising the following steps:

[0027] S1. Surveying and Setting Out: Based on the surveying control points provided by the design unit, measure the positioning line of the box-type masonry slope protection and the original ground elevation;

[0028] S2. Excavation and slope trimming of foundation pit: Trim the slope and excavate the foundation pit according to the designed slope gradient, and reserve the protective layer by manual excavation and bottom cleaning.

[0029] S3. Template Creation and Installation: Create and install the basic template;

[0030] S4. Foundation Concrete Pouring: C20 concrete is used to pour the foundation unit and then cured.

[0031] S5. Integrated filter layer construction: including laying geotextile, setting crushed stone filter layer and bidirectional reinforced geogrid;

[0032] S6. Box block masonry: Construct the first layer of box blocks, fix them to the foundation unit, and fill the internal cavity with coarse aggregate;

[0033] S7. Layered construction and ecological filling: The subsequent layers of box blocks are laid in a progressive manner from bottom to top. Adjacent blocks are fixed to each other by connectors. Coarse aggregate or planting soil is selectively filled into the internal cavity of each layer of blocks according to the design position to form a stepped structure until the revetment construction at the design elevation is completed.

[0034] Preferably, S5 specifically includes: first laying an inner layer of geotextile, then spreading and leveling crushed stone in layers on the inner layer of geotextile to form the crushed stone filter layer, then laying a bidirectional reinforced geogrid on the crushed stone filter layer, and finally laying an outer layer of geotextile on the outside of the bidirectional reinforced geogrid.

[0035] (III) Beneficial Effects

[0036] This invention provides a stepped box-type block ecological revetment structure and its construction method, which has the following advantages compared with the prior art:

[0037] (1) In this embodiment of the invention, a stepped, receding arrangement is used, with the center of gravity of the blocks biased towards the backfill side. Combined with the dual fixation of transverse bolts and longitudinal injection-molded connectors, the overturning resistance and sliding resistance of the revetment structure are improved compared to loose blocks without connectors. Transverse bolts provide the integrity of blocks in the same layer, while longitudinal connectors ensure the coordinated force distribution between blocks in the upper and lower layers. The box-shaped blocks are provided with permeable holes that penetrate the wall panels, enabling the internal cavity of the box-shaped blocks to communicate with the external environment (water-facing side, backfill side, and bottom). At the same time, different opening ratios are set, which can limit the flow of water, which is conducive to the full absorption of water by plant roots, the natural sedimentation of suspended particles in the water, and the full contact between pollutants and filling materials.

[0038] (2) In this invention, multiple raised structures are formed on the surface of the geotextile facing the gravel filter layer through processes such as hot pressing. These raised structures can be hemispherical, conical, or other regular shapes, arranged in an array. During construction, when the gravel filter layer is laid and compacted onto the inner geotextile layer, the gravel particles embed into the recesses between these raised structures, or the raised structures themselves embed into the voids of the gravel layer, thus forming a micro-interlocking effect. This micro-interlocking structure formed by the raised structures and the gravel filter layer effectively increases the interfacial friction between the geotextile and the gravel filter layer, effectively resisting the sliding force of the geotextile on the slope and preventing the inner geotextile from slipping or wrinkling under the earth pressure behind the wall. This solves the problem of traditional flat-laid geotextiles being prone to slippage and wrinkling on steep slopes.

[0039] (3) The present invention provides a reinforced composite filter layer system after the box-type masonry blocks, which can effectively solve the problems of water accumulation and soil loss behind the wall, so as to realize the multi-functional integration of biological habitat and greening planting, and improve the long-term stability and durability of the bank protection. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] The invention will now be further described with reference to the accompanying drawings.

[0042] Figure 1 This is a schematic cross-sectional view of the stepped box-type block ecological revetment structure of the present invention;

[0043] Figure 2 This is a three-dimensional structural diagram of the box-shaped block in this invention;

[0044] Figure 3This is a schematic diagram of the stacking and fixing of box-shaped blocks in this invention;

[0045] Figure 4 This is a cross-sectional view of the box-shaped block in this invention.

[0046] Figure 5 This is a partial cross-sectional view of the integrated filter layer in this invention;

[0047] Figure 6 This is a schematic diagram of the integrated filter layer in this invention.

[0048] Figure 7 This is a flowchart illustrating the construction process of the present invention.

[0049] In the diagram: 1. Box block; 2. Geotextile; 3. Foundation unit; 4. Tubular component; 101. Large hole; 102. Medium hole; 103. Micro hole; 104. Drainage pipe; 105. Connecting hole; 106. Reinforcing rib; 107. Connecting bolt hole. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely. Obviously, the described embodiments are only some embodiments of the present invention, 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.

[0051] like Figures 1 to 7 As shown, this embodiment of the invention provides a stepped box-type block ecological revetment structure. Specifically, refer to... Figure 1 The stepped box-type block ecological revetment structure includes at least one basic unit 3, multiple prefabricated hollow box-type blocks 1, an integrated reverse filter system, and an ecological greening layer.

[0052] In specific implementation, the foundation unit 3 can be a cast-in-place C20 concrete structure, laid at the bottom of the foundation pit, serving as the load-bearing benchmark for the entire revetment structure. Its top surface is leveled to ensure complete contact with the bottom of the upper box-shaped blocks 1, thereby uniformly transferring the load and preventing deformation or cracking of the upper blocks due to uneven foundation settlement.

[0053] The multiple box-shaped masonry blocks 1 are factory-prefabricated hollow concrete structures, arranged in a stepped, receding pattern from bottom to top. During construction, each layer of blocks is recessed a certain width (e.g., 8-12cm) towards the backfill side (i.e., the direction behind the wall) compared to the layer below, forming a stepped slope with an approximate 1:0.5 gradient behind the wall. Adjacent box-shaped masonry blocks 1 are connected to each other using connectors: 1.2cm galvanized bolts are used to fasten the transverse blocks within the same layer through the connecting holes 105 on the side of the block; anti-aging injection-molded connectors are used to fix the longitudinal blocks between upper and lower layers, inserted into the pre-drilled bolt holes 107. This dual connection method allows the individual box-shaped masonry blocks 1 to form a unified load-bearing structure, collectively resisting the soil and water pressure behind the wall.

[0054] The integrated filter system is installed behind the wall of the box-shaped block 1 (i.e., on the back side of the soil). This filter system includes at least one layer of geotextile, a crushed stone filter layer, and a bidirectional reinforced geogrid. The geotextile acts as a permeable material and retains soil, allowing water accumulated behind the wall to seep into the crushed stone filter layer while preventing soil particle loss. The crushed stone filter layer provides a smooth drainage channel for seepage water and guides the water towards the box-shaped block 1. The bidirectional reinforced geogrid enhances the tensile strength of the slope, preventing slope cracking and landslides, and also embeds the crushed stone in the filter layer, reducing rainwater erosion.

[0055] The ecological greening layer is set in the internal cavity of at least a portion of the box-shaped blocks 1. Specifically, for the box-shaped blocks 1 located above the normal water level, there are generally two or more layers of box-shaped blocks 1. Their internal cavities are not filled with gravel, but are backfilled with planting soil (clay) for later planting of wetland or terrestrial plants to form a green landscape.

[0056] The aforementioned box-shaped masonry block 1 has permeable holes on its wall panels. These permeable holes penetrate the wall panels, connecting the internal cavity of the box-shaped masonry block 1 with the external environment (the water-facing side, the soil-backing side, and the bottom). Based on these permeable holes, water accumulated behind the wall can enter the internal cavity of the box-shaped masonry block 1 through the permeable holes on the soil-backing side, and then be discharged into the river channel through the permeable holes on the water-facing side; conversely, river water can also enter the interior of the box-shaped masonry block 1, realizing hydrological connectivity between the bank slope and the river channel.

[0057] More importantly, depending on the different height positions of the box-shaped blocks 1 in the revetment structure, their internal cavities are selectively filled with coarse aggregate or planting soil. Specifically: for box-shaped blocks 1 located below the normal water level (underwater zone) or in the water level fluctuation zone (such as the first and second layers), the internal cavities are filled with coarse aggregate such as crushed stone with a particle size of 12-25cm to increase the self-weight of the blocks and improve their erosion resistance; for box-shaped blocks 1 located above the normal water level (the third layer and above), the internal cavities are filled with planting soil to form the ecological greening layer.

[0058] In the above embodiment, by arranging the box-shaped blocks 1 in a stepped manner and fixing them together with connectors to form a whole, the center of gravity of the box-shaped blocks 1 is designed to be offset from the soil direction, thereby enhancing the overall anti-overturning and anti-sliding capabilities of the revetment structure.

[0059] In one embodiment, the integrated reverse filtration system was further optimized based on the above embodiments. (Refer to...) Figure 6 and Figure 7 The integrated reverse filtration system includes at least two layers of geotextile 2, namely an inner geotextile and an outer geotextile, a crushed stone reverse filtration layer and a bidirectional reinforced geogrid laid between the inner and outer geotextiles; the bidirectional reinforced geogrid is laid on the crushed stone reverse filtration layer; wherein, the inner geotextile is closer to the backfill side (i.e., the original soil or backfill behind the wall), and the outer geotextile is closer to the back soil sidewall of the box block 1.

[0060] Specifically, the inner geotextile layer can be made of high-strength reinforced polyester geotextile, with multiple raised structures formed on the surface facing the gravel filter layer through processes such as hot pressing. These raised structures can be hemispherical, conical, or other regular shapes, arranged in an array (e.g., hemispherical protrusions with a diameter of 5mm, a height of 3mm, and a spacing of 10mm). During construction, when the gravel filter layer is laid and compacted onto the inner geotextile layer, the gravel particles embed into the recesses between these raised structures, or the raised structures themselves embed into the voids in the gravel layer, thus forming a micro-interlocking effect. This micro-interlocking structure formed by the raised structures and the gravel filter layer effectively increases the interfacial friction between the geotextile and the gravel filter layer, effectively resisting the sliding force of the geotextile on the slope and preventing the inner geotextile from slipping or wrinkling under the earth pressure behind the wall. This solves the problem of traditional flat-laid geotextiles being prone to slippage and wrinkling on steep slopes.

[0061] Furthermore, in one embodiment, a differentiated design of the permeable holes is proposed, specifically an asymmetric gradient aperture design for the permeable holes on the box-shaped block 1. (Refer to...) Figure 2 and Figure 4 The permeable holes specifically include three specifications:

[0062] The first type involves large-diameter permeable holes 101 formed on the water-facing sidewall of the box-shaped block 1. These holes have a relatively large diameter, for example, 5-6 cm, and are distributed in a staggered pattern on the wall panel, resulting in a high porosity (e.g., 15%-20%). Compared to a rectangular distribution, the staggered pattern allows for more holes to be accommodated within the same area, while avoiding stress concentration and maintaining the structural strength of the wall panel. Its main function is to allow water within the internal cavities of the block to drain quickly and smoothly into the river channel, preventing water accumulation inside the block.

[0063] The second type involves medium-diameter permeable holes 102 formed on the back soil sidewall of the box-shaped block 1. The diameter of these holes is smaller than the large holes on the water-facing side, for example, 2-3 cm. More importantly, their opening ratio is designed to be lower than that of the large-diameter permeable holes 101, for example, only about 40% of the opening ratio on the water-facing side. This means that the holes on the back soil sidewall are smaller and sparser, effectively limiting the flow of water accumulated behind the wall into the block.

[0064] The third type is the microporous permeable hole 103 formed on the bottom wall of the box-shaped block 1. This hole has the smallest diameter, for example, 0.8-1 cm, and the lowest porosity (for example, 2%-3%). It is mainly used as a long-term seepage channel.

[0065] In the above embodiment, the low-permeability pores on the back side restrict water flow, effectively slowing the rate at which water seeps into the masonry blocks from behind the wall; while the high-permeability pores on the water-facing side ensure unobstructed drainage into the river. The combined effect of these two features results in a relatively long retention time of water within the masonry blocks (especially in the clay-filled ecological zone), preventing water accumulation due to poor drainage. This retention time facilitates the full absorption of water by plant roots, the natural settling of suspended particles in the water, and sufficient contact between pollutants and the filling material. The micropores at the bottom provide a long-term, stable seepage path, and because their pore size is smaller than the particle size of the internal gravel filling, they effectively prevent gravel leakage.

[0066] In one embodiment, the permeable hole structure and the box-type block 1 structure are further improved. (Refer to...) Figure 2 and Figure 4 Specifically:

[0067] On one hand, a guide pipe 104 is pre-embedded in the large-diameter permeable hole 101 on the water-facing sidewall. This guide pipe 104 can be made of corrosion-resistant materials such as polyethylene, with one end extending beyond the outer surface of the water-facing sidewall by approximately 2-3 cm. Furthermore, the inlet of the guide pipe 104 is designed to slope downwards, with an angle of, for example, 15°-20°. This structure ensures that the inlet end of the guide pipe 104 faces downwards, effectively preventing blockage by floating debris and direct inflow from the slope.

[0068] In the above embodiment, the pre-embedded inclined guide pipe 104 can effectively prevent floating objects (such as leaves, aquatic plants, plastic sheets, etc.) in the river from directly clogging the permeable holes, because the floating objects are not easy to move upstream and enter the downward-sloping pipe opening when moving with the water flow. At the same time, when the slope runoff flows downhill, the downward-sloping pipe opening can also prevent the water flow from directly pouring into the interior of the block and eroding the filling material.

[0069] On the other hand, longitudinally extending stress-dispersing ribs 106 are also provided on the back side wall of the box-shaped block 1. The ribs 106 are prefabricated integrally with the main body of the box-shaped block 1. The height is the same as that of the block, the width is 5-8cm, and the thickness is 3-5cm. Multiple ribs 106 are arranged parallel to each other along the length of the block (with a spacing of 20-30cm).

[0070] Longitudinal ribs 106 are provided on the soil-backed sidewall of the box-type masonry block 1. During block installation, the ribs 106 press against the surface of the filter layer, pressing the outer geotextile into the surface voids of the crushed stone filter layer, forming an embedded state. After the ribs 106 are embedded in the crushed stone layer, the mechanical interlocking between the block and the filter layer is increased. When the block is subjected to soil pressure behind the wall and has a tendency to slide towards the water side, the embedded ribs are subjected to passive earth pressure from the crushed stone layer, generating anti-sliding resistance, improving the shear capacity between the block and the filter layer interface, and reducing the horizontal slippage of the block. As stiffening ribs, the ribs improve the structural stiffness of the soil-backed sidewall of the block and reduce the flexural deformation of the block under earth pressure.

[0071] The embedded ribs make the contact between the blocks and the filter layer closer, reducing the gaps between the blocks and the filter layer after installation, which is conducive to the orderly seepage of water behind the wall.

[0072] The outer geotextile is located between the ribs and the crushed stone layer, serving as an isolation and protection mechanism to prevent the ends of the ribs from directly contacting the edges of the crushed stone and reduce the damage to the concrete caused by local stress concentration. At the same time, the geotextile maintains its permeability and does not affect the drainage function of the filter layer.

[0073] Furthermore, in a specific embodiment, the aforementioned box-shaped block 1 can be configured such that the thickness of the back soil sidewall is greater than the thickness of the water-facing sidewall. This is achieved by providing thickened ribs inside the back soil side of the box-shaped block 1, combined with... Figures 2-4 The schematic asymmetrical geometry enables the center of gravity of box block 1 to be designed to be biased towards the backfill side, thereby improving its overturning resistance.

[0074] In one embodiment, a vertical tubular member 4 is added inside the box-shaped block 1. (Refer to...) Figure 4 and Figure 5 In at least one (usually each) box-shaped block 1, a vertical tubular member 4 is provided within the internal cavity. This tubular member 4 can be a PVC pipe, PE pipe, or other corrosion-resistant material pipe, with a diameter significantly smaller than the size of the block cavity (e.g., 8 cm in diameter). The tubular member 4 has multiple through holes (0.5-1 cm in diameter, spaced 5-10 cm apart) on its wall, allowing for moisture and material exchange between its internal space and the filling material within the block cavity.

[0075] The tubular component 4 is filled with a functional filling material that is different from the internal cavity of the box-shaped block 1. Both the upper and lower ends of the tubular component 4 are open structures to facilitate the entry and exit of water from the ends.

[0076] Furthermore, the tubular components 4 are open at both ends, and at least one row of tubular components 4 is arranged within the box-shaped blocks 1 along the direction from the water-facing side to the back soil side. The adjacent layers of box-shaped blocks 1 are horizontally offset due to their stepped progression. By aligning the front row of tubular components 4 near the water-facing side in the upper layer with the rear row of tubular components 4 near the back soil side in the lower layer, the lower outlet of the upper tubular component 4 directly faces the upper inlet of the lower tubular component 4. After water flows out from the upper pipe, it falls into the lower pipe by gravity, thus achieving fluid communication between the upper and lower tubular components 4. In this way, a zigzag vertical channel network is formed along the height of the revetment.

[0077] The above embodiments provide a preferred path for the rapid dissipation of water behind the wall through a vertical channel network. When the water level fluctuates, the pore water pressure can be quickly released through these low-resistance channels, improving the dynamic water stability of the revetment. Simultaneously, the functional filler within the tubular component 4 and the main filler within the block cavity form a composite structure, each capable of performing different functions. The connectivity of the vertical channels also makes it possible to inject repair materials or nutrients into the revetment if needed in the future.

[0078] Furthermore, the functional filling materials within the tubular component 4 were designed differently to meet the functional requirements of blocks at different levels, specifically:

[0079] For box-shaped blocks 1 with internal cavities filled with coarse aggregate (crushed stone), such as the first and second layers of blocks located in underwater areas or water level fluctuation zones, the functional filling material in the tubular components 4 is coarse sand. The particle size of the coarse sand is typically 2-4 mm, and it has a very high permeability coefficient.

[0080] For box-shaped blocks 1 with internal cavities filled with planting soil, such as the third layer and above blocks located above the normal water level, the functional filling material in the tubular components 4 is an adsorbent material. This adsorbent material can be ceramsite, zeolite, activated carbon, or a mixture thereof. For example, ceramsite and zeolite can be mixed at a volume ratio of 1:1. Ceramsite (particle size 5-10 mm) has a rough, porous surface and low bulk density, making it an excellent carrier for microbial attachment; zeolite (particle size 3-8 mm) has unique ion exchange properties and a strong adsorption capacity for ammonia nitrogen in water.

[0081] In the above embodiments, the tubular component 4 forms a local functional core column inside the box-shaped block 1. For box-shaped blocks 1 whose internal cavities are filled with coarse aggregate (crushed stone), the coarse sand core column inside the pipe has high permeability and can serve as a local drainage path. When siltation occurs, the drainage function can be restored by removing and replacing the core column material without replacing the crushed stone throughout the block. For box-shaped blocks 1 whose internal cavities are filled with planting soil, the adsorbent material inside the pipe (such as a mixture of expanded clay and zeolite) can adsorb eutrophic salts flowing through the water body and provide an attachment carrier for microorganisms, thereby improving the water purification capacity of the bank protection to a certain extent.

[0082] Furthermore, in one embodiment, the interface pore size matching between the crushed stone filter layer and the box-shaped block 1 was designed. Specifically, in the crushed stone filter layer, the particle size of the crushed stone in a local area adjacent to the back soil sidewall of the box-shaped block 1 (e.g., a 10-15cm thick layer of crushed stone directly against the back of the block) is not arbitrary, but selected according to the pore size of the permeable holes (medium-diameter permeable holes 102) on the back soil sidewall of the box-shaped block 1 at the corresponding location. The matching principle is: the lower limit of the crushed stone particle size is slightly larger than the permeable hole diameter, or is on the same order of magnitude as the permeable hole diameter, so that the crushed stone particles cannot enter the internal cavity of the block through the permeable holes, and at the same time, the filling material (crushed stone or clay particles) inside the block is not allowed to flow into the filter layer through the permeable holes.

[0083] The specific matching relationships are as follows:

[0084] If the permeable hole diameter of the back wall of a certain layer of masonry blocks is 3cm, then the matching crushed stone particle size should be 3-5cm (i.e., the minimum particle size is not less than 3cm and the maximum particle size is not more than 5cm).

[0085] If the aperture is 2.5cm, then it should be matched with crushed stone with a particle size of 2.5-4cm;

[0086] If the aperture is 2cm, then it is matched with crushed stone with a particle size of 2-3cm.

[0087] This embodiment, through physical sieving and matching, eliminates cross-contamination between the two different media (block filler and backfill filter material) within the revetment structure at the source. This ensures that the filter layer maintains its designed high permeability over the long term and will not become clogged due to the mixing of fine soil; it also ensures the stability of the filler material inside the blocks, preventing voids caused by the loss of gravel or clay, which could lead to structural deformation. This pore size matching maintains the permeability stability of the revetment throughout its entire lifespan.

[0088] In one embodiment, a water-swellable material is incorporated into the gravel filter layer corresponding to the box-shaped block 1 used to form the ecological greening layer.

[0089] Specifically, for box-shaped blocks 1 filled with planting soil above the normal water level, a certain proportion (e.g., 3%-10%) of water-swellable material is incorporated into the corresponding gravel filter layer (especially the matching gravel layer near the back soil sidewall of the block, i.e., the aforementioned local gravel layer with a thickness of 10-15cm). This water-swellable material is preferably sodium-based bentonite particles, with a particle size comparable to the matching gravel particle size (e.g., 1-2mm), facilitating uniform mixing. Bentonite has the characteristic of expanding in volume upon contact with water and returning to its original shape after water loss.

[0090] Under normal conditions (when the groundwater level behind the wall is low), the bentonite is in a contracted state, maintaining high permeability and smooth drainage in the filter layer. When there is continuous rainfall or a sudden drop in water level, the groundwater level behind the wall rises, and water enters the filter layer. The bentonite expands upon contact with water, increasing in volume and blocking some of the voids between the gravel, temporarily reducing the permeability coefficient of the gravel filter layer near the box-shaped block 1. This effectively slows down the rapid rise in the water level behind the wall, and more importantly, prevents the migration and loss of clay particles within the box-shaped block 1 driven by water flow. When the water level drops, the bentonite loses water and contracts, automatically restoring the drainage function of the filter layer. This adaptive characteristic of low permeability at high water levels and high permeability at low water levels effectively inhibits clay loss and dynamically maintains permeability stability.

[0091] Furthermore, this embodiment of the invention also provides a construction method for a stepped box-type block ecological revetment structure, specifically as follows:

[0092] S1. Surveying and Setting Out

[0093] Based on the measurement control points provided by the design unit, the positioning lines and original ground elevation of the box-type block revetment were measured using a total station or GPS. A control stake was set every 10-20m along the revetment axis, and the foundation excavation edge line, the inner and outer edges of the blocks, and the retreat position of each layer of blocks were marked. The retreat position corresponds to the structural design of the stepped box-type blocks 1 arranged in a descending manner from bottom to top, with a retreat width of 10cm, to form a stepped structure with a slope of 1:0.5 behind the wall. The measurement results were recorded to provide a positioning benchmark for subsequent construction.

[0094] S2, Excavation of the foundation pit

[0095] Excavate the foundation pit according to the designed slope gradient (usually 1:1.0~1:1.5). Mechanical excavation is carried out using an excavator, leaving a 100-200mm protective layer to avoid disturbing the original soil at the base. The protective layer is excavated and cleaned manually to ensure the base is flat, free of loose soil and water accumulation. The bottom of the foundation pit corresponds to the laying position of foundation unit 3. Foundation unit 3 serves as the load-bearing benchmark for the revetment structure, and its top surface must be completely flush with the bottom of the subsequent box-type blocks 1. Excavated soil must be promptly removed from the foundation pit, and no waste soil should be piled up at the pit's edge.

[0096] S3. Template Creation and Installation

[0097] The formwork for foundation unit 3 was fabricated on-site using wooden molds. The surface of the wooden mold in contact with the concrete should be smooth, flat, and free of holes. Joints should be flush and sealed with tape or silicone sealant to prevent grout leakage. Corners should be reinforced with strips or beveled to ensure sharp edges at the corners of foundation unit 3. Before installation, the base should be leveled to the designed slope and compacted. After assembly, the formwork was secured with wooden strips, and steel pipe supports were installed on the outside, with a spacing of no more than 1 meter, to prevent displacement or protrusion of the formwork during concrete pouring.

[0098] S4, Foundation Concrete Pouring

[0099] C20 concrete was used for pouring foundation unit 3, with the concrete slump controlled between 120-160mm. Before pouring, the uniformity and slump of the concrete were strictly checked. After the concrete was poured into the formwork, it was promptly compacted using an immersion vibrator. After curing, the top surface of foundation unit 3 should be flat, serving as the load-bearing reference for box-type blocks 1.

[0100] S5, Integrated Filter Layer Construction

[0101] 5.1 Slope trimming

[0102] After the foundation concrete reaches the design strength, the original soil on the back slope of the wall is cleaned and debris is removed, such as tree roots, weeds, and construction waste. Then, backfilling and trimming are carried out according to the design slope (1:0.5). The thickness of each backfill layer shall not exceed 30cm. Compaction is carried out with a small vibratory roller, and the compaction degree shall not be less than 0.93.

[0103] 5.2 Laying the inner layer of geotextile

[0104] After slope trimming, the inner layer of geotextile is laid. The inner layer uses 250g / m² high-strength reinforced polyester geotextile (tensile strength ≥50kN / m). If a raised structure is required, the inner layer of geotextile should be pre-heat-pressed to form a hemispherical array of raised dots (5mm diameter, 3mm height, 10mm spacing), with the raised surfaces facing the gravel layer. The geotextile is laid along the slope, with the upper layer overlapping the lower layer, and the overlap width is not less than 30cm. The top is fixed with anchor grooves, with anchor spacing of 1m.

[0105] 5.3 Laying the crushed stone filter layer

[0106] The total thickness of the crushed stone filter layer is 50cm, and it is constructed using a layered spreading and compaction method. Each layer is 15-20cm thick and compacted using a small-tonnage (≤2t) vibratory roller or plate vibrator, with each layer compacted 3-4 times. The crushed stone gradation adopts a gradient gradation: from the fill side to the block side, it consists of coarse gravel (5-20mm), fine gravel (2-5mm), and coarse sand (0.5-2mm), forming a continuous gradual gradation.

[0107] 5.4 Construction of the pore size matching layer

[0108] Within a 10cm thickness adjacent to the back of box-type block 1, a specific particle size of crushed stone is laid, matching the pore size of the permeable holes in the back wall of the corresponding layer of block. The specific matching relationships are as follows: underwater zone (pore size 3cm) uses crushed stone with a particle size of 3-5cm (minimum particle size not less than 3cm); water level fluctuation zone (pore size 2.5cm) uses crushed stone with a particle size of 2.5-4cm; above normal water level (pore size 2cm) uses crushed stone with a particle size of 2-3cm; above normal water level (corresponding to the third layer and above blocks, where the permeable hole 102 in the back wall has a pore size of 2cm) uses crushed stone with a particle size of 1-2cm. The crushed stone in the matching layer should be pre-screened before paving to ensure the particle size meets the requirements, preventing the filling material inside the cavity of box-type block 1 from entering the crushed stone filter layer.

[0109] 5.5 Soil Mixing

[0110] For the back filter layer matching layer crushed stone in areas above the normal water level (corresponding to the back filter layer behind the wall of the box block 1 with the third layer and above and the interior filled with planting soil), sodium-based bentonite particles (particle size 1-2mm) are added at a ratio of 10% before paving, and then dry-mixed evenly with a forced mixer (mixing time not less than 2 minutes) before paving.

[0111] 5.6 Laying the outer layer of geotextile

[0112] After the crushed stone filter layer is laid, leveled, and compacted, a bidirectional reinforced geogrid is laid on top of it; then, an outer geotextile is laid on the outer surface. The outer geotextile uses 300g / m² or 400g / m² needle-punched filament geotextile, and is overlapped with the upper width overlapping the lower width, with an overlap width of not less than 30cm. At the top and bottom of the slope, the outer geotextile must have a wrapping length of not less than 1m to cover the upper and lower edges of the crushed stone layer, and be fixed with soil anchors or pressure strips to form a sandwich structure.

[0113] S6, Box Block Masonry

[0114] 6.1 First-floor block laying

[0115] Once the concrete strength of foundation unit 3 reaches the design strength, clean the top surface of the foundation. Prefabricated box-shaped masonry blocks 1 (strength grade not lower than C30) are transported to the foundation in batches. Box-shaped masonry blocks 1 are hollow structures with permeable holes, including large-diameter permeable holes 101 (distributed in a quincunx pattern) on the water-facing sidewall, medium-diameter permeable holes 102 on the soil-facing sidewall, and micro-diameter permeable holes 103 on the bottom wall. Based on the surveyed and laid-out positioning lines, lay the first layer of box-shaped masonry blocks 1, ensuring the bottom surface is completely flush with foundation unit 3, with a horizontal deviation not exceeding 5mm and an axial position deviation not exceeding 10mm.

[0116] 6.2 Lateral Connection

[0117] Between adjacent box-type blocks 1 on the same floor, 1.2cm galvanized bolts (including matching nuts and washers) are used for connection through connection holes 105. The bolt tightening torque is controlled at 30-50 N·m, and anti-loosening washers are installed.

[0118] 6.3 Pre-design of tubular components

[0119] Before filling with crushed stone, place the vertical tubular components 4 (PVC or PE material, 8cm in diameter, with 0.5cm diameter holes spaced 5cm apart, and pre-drilled joint grooves at both ends) at the four corners of the internal cavity of the box-shaped block 1. The lower end of the tube contacts the bottom wall of the block, and the upper end has a pre-drilled joint groove for connecting with the tubular components 4 in adjacent box-shaped blocks 1, forming a vertical channel network inside the revetment structure. Fill the tubular components 4 with functional filling material: For box-shaped blocks 1 (first layer) with coarse aggregate filling the internal cavity, fill with coarse sand (2-4mm particle size), gently tapping the tube wall while filling to ensure compaction.

[0120] 6.4 Internal gravel filling

[0121] The internal cavity of the first layer of box-shaped blocks 1 is filled with crushed stone (coarse aggregate) with a particle size of 12-25cm. Filling is done in two layers, with each layer compacted using a small vibrator to ensure the crushed stone is dense and the gaps are uniform. Filling stops about 5cm from the top surface of the block, leaving space for the connectors of the upper blocks.

[0122] S7, Layered Construction and Ecological Filling

[0123] 7.1 Second layer masonry

[0124] Construct the second layer of box-shaped blocks 1 according to the stepped retreat requirement (retreat width 10cm). Clean the top surface of the first layer of blocks before construction. The second layer of blocks is connected to the first layer of blocks using anti-aging injection-molded connectors: these connectors are made of nylon PA12 with 30% glass fiber, are black and UV resistant, and have a pin or snap-fit ​​structure; insert the lower part of the connector into the connecting bolt hole 107 at the top of the first layer of blocks, then align the pre-drilled hole at the bottom of the second layer of blocks with the upper part of the connector, and gently tap to make the block fall into place. Horizontal blocks are also connected using 1.2cm galvanized bolts. The internal cavity of the second layer of box-shaped blocks 1 is still filled with crushed stone with a particle size of 12-25cm. The tubular components 4 are pre-set and filled in the same way as in S6.3 and S6.4.

[0125] 7.2 Masonry construction of the third layer and above

[0126] Following the steps described above, subsequent box-shaped blocks 1 are laid layer by layer from bottom to top, progressively receding outwards. For the third layer and above of box-shaped blocks 1 (located above the normal water level), the internal cavity is used to form an ecological green layer, and the filling method is as follows:

[0127] First, lay a layer of geotextile (250g / m² fine geotextile) at the bottom and four walls of the internal cavity of the box block 1. The geotextile extends 10-15cm above the top surface of the block so as to cover the planting soil.

[0128] Then, the tubular component 4 is pre-set, in the same position as before. For the box-shaped block 1 whose internal cavity is filled with planting soil, the tubular component 4 is filled with an absorbent material: ceramsite (particle size 5-10mm) and zeolite (particle size 3-8mm) are mixed in a volume ratio of 1:1.

[0129] Finally, backfill the main cavity of the box-shaped block 1 with planting soil (clay). The clay should be pre-dried, crushed, and sieved (2cm mesh). Backfilling should be done in two layers, each 15-20cm thick, and gently compacted, avoiding over-compaction to prevent affecting permeability. Backfill to about 5cm from the top surface of the block, then wrap the reserved geotextile over the clay surface and secure it with U-shaped nails.

[0130] 7.3 Synchronous backfilling behind the wall

[0131] After each layer of box-shaped blocks 1 is completed, the crushed stone filter layer behind the wall of that layer should be backfilled to the top elevation of the block layer in a timely manner (the main filter layer has been completed in S5, and only backfilling is required here to make it level), to ensure that the crushed stone is in close contact with the back soil sidewall of box-shaped blocks 1 without leaving any gaps.

[0132] 7.4 Green Planting and Maintenance

[0133] After the entire revetment is constructed, greening will be carried out in the planting soil of the third layer and above box-shaped blocks 1. Plants selected should be native species with well-developed root systems, tolerant of moisture and drought, such as reeds, calamus, and irises. During planting, holes will be dug in the clay surface, the plant roots will be inserted, the soil will be covered and compacted, and the soil thoroughly watered. After construction, maintenance will be carried out for at least 14 days. During this period, the planting soil should be kept moist (but not waterlogged), and plants with low survival rates should be replanted promptly. Debris and garbage on the revetment surface should be cleaned up.

[0134] It should be noted that, in this document, 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 process, method, article, or apparatus.

[0135] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A stepped box-type block ecological revetment structure, characterized in that, include: At least one basic unit (3) is laid at the bottom of the foundation pit, serving as the bearing benchmark for the revetment structure; Multiple prefabricated hollow box-shaped blocks (1) are arranged in a stepped manner from bottom to top, and adjacent box-shaped blocks (1) are fixedly connected to each other by connectors. An integrated reverse filtration system is installed behind the wall of the box-shaped block (1). The reverse filtration system includes at least one layer of geotextile and a crushed stone reverse filtration layer wrapped by the geotextile. And an ecological greening layer, which is set in the internal cavity of at least a portion of the box-shaped blocks (1); The box-shaped block (1) is provided with permeable holes to connect its internal cavity with the external environment; and, depending on the different height positions of the box-shaped block (1) in the revetment structure, its internal cavity is selectively filled with coarse aggregate or planting soil for forming the ecological greening layer.

2. The stepped box-type block ecological revetment structure according to claim 1, characterized in that, The integrated reverse filtration system includes: At least two layers of geotextile (2), namely an inner geotextile and an outer geotextile, a gravel filter layer and a bidirectional reinforced geogrid laid between the inner geotextile and the outer geotextile; the bidirectional reinforced geogrid is laid on the gravel filter layer, and the inner geotextile is closer to the fill side than the outer geotextile. Furthermore, the inner geotextile has multiple raised structures formed on the side surface facing the crushed stone filter layer.

3. The stepped box-type block ecological revetment structure according to claim 1, characterized in that, The permeable holes on the box-shaped block (1) include: Large-diameter permeable holes (101) are opened on the water-facing side wall of the box-shaped block (1). Medium-diameter permeable holes (102) are opened on the back soil sidewall of the box-shaped block (1), and the opening ratio of the medium-diameter permeable holes (102) is lower than that of the large-diameter permeable holes (101). And micro-pore permeable holes (103) opened on the bottom wall of the box-shaped block (1).

4. The stepped box-type block ecological revetment structure according to claim 3, characterized in that, A guide pipe (104) is pre-embedded in the large-diameter permeable hole (101) on the water-facing sidewall. One end of the guide pipe (104) extends out of the outer surface of the water-facing sidewall and is inclined downward; and / or, a longitudinally extending stress-dispersing rib (106) is provided on the back sidewall of the box-shaped block (1).

5. The stepped box-type block ecological revetment structure according to claim 1, characterized in that, At least one of the box-shaped blocks (1) has a vertical tubular member (4) in its internal cavity. The tubular member (4) is filled with a functional filling material that is different from the internal cavity of the box-shaped block (1). The upper and lower ends of the tubular member (4) are open for water to enter and exit.

6. The stepped box-type block ecological revetment structure according to claim 5, characterized in that, For a box-shaped block (1) whose internal cavity is filled with coarse aggregate, the functional filling material in the tubular component (4) inside is coarse sand; for a box-shaped block (1) whose internal cavity is filled with planting soil, the functional filling material in the tubular component (4) inside is an absorbent material.

7. The stepped box-type block ecological revetment structure according to claim 1, characterized in that, In the crushed stone filter layer, the local crushed stone layer adjacent to the back soil sidewall of the box block (1) has a crushed stone particle size that matches the permeable hole size on the back soil sidewall of the box block (1) at the corresponding position, so as to prevent the filling material of the internal cavity of the box block (1) from entering the crushed stone filter layer.

8. The stepped box-type block ecological revetment structure according to claim 7, characterized in that, Water-swellable material is incorporated into the gravel filter layer behind the wall corresponding to the box-shaped masonry block (1) used to form the ecological greening layer.

9. A construction method for a stepped box-type block ecological revetment structure as described in any one of claims 1 to 8, characterized in that, Includes the following steps: S1. Surveying and setting out: Based on the surveying control points provided by the design unit, measure the positioning line of the box-type masonry slope protection and the original ground elevation; S2. Excavation and slope trimming of foundation pit: Trim the slope and excavate the foundation pit according to the designed slope gradient, and reserve the protective layer by manual excavation and bottom cleaning. S3. Template Creation and Installation: Create and install the basic template; S4. Foundation concrete pouring: C20 concrete is used to pour the foundation unit (3) and then cured. S5. Integrated filter layer construction: including laying geotextile, setting crushed stone filter layer and bidirectional reinforced geogrid; S6. Box block masonry: Construct the first layer of box blocks (1), fix them on the foundation unit (3), and fill the internal cavity with coarse aggregate; S7. Layered construction and ecological filling: The subsequent layers of box-shaped blocks (1) are laid down layer by layer from bottom to top. Adjacent blocks are fixed to each other by connectors. According to the design position of each layer of blocks, coarse aggregate or planting soil is selectively filled into the internal cavity to form a stepped structure until the revetment construction at the design elevation is completed.

10. A construction method for a stepped box-type block ecological revetment structure as described in claim 9, characterized in that: S5 specifically includes: first laying an inner layer of geotextile, then spreading and leveling crushed stone in layers on the inner layer of geotextile to form the crushed stone filter layer, then laying a bidirectional reinforced geogrid on the crushed stone filter layer, and finally laying an outer layer of geotextile on the outside of the bidirectional reinforced geogrid.

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