Ecological-structure-based self-repairing protection structure for earth-rock dam and construction method thereof

Abstract

This invention relates to the field of hydraulic engineering and geotechnical engineering protection technology, and discloses an eco-structure-based self-healing protection structure for earth-rock dams and its construction method. The structure includes a rockfill layer, which consists of a root anchoring layer, a root penetration layer, and a hydraulic drainage layer. The average particle size, paving thickness, and interlocking density of the boulders in each layer are dynamically calculated and determined by a layered particle size adaptive ratio optimization algorithm based on the hydraulic and geological conditions of different areas of the dam slope. A deep-rooted turf protection layer consists of topsoil laid on the surface of the root anchoring layer and deep-rooted plants planted on the topsoil. The roots of the deep-rooted plants penetrate the rockfill layer, wrapping the boulders and extending into the surface soil of the dam slope, forming a bio-gabion structure where the roots wrap around the rockfill. This invention combines the immediacy of engineering protection with the ecological durability of plant slope protection, completely eliminating artificial synthetic reinforcement materials, and has advantages such as strong erosion resistance, environmental friendliness, high durability, and low cost.

Description

Technical Field

[0001] This invention relates to the field of water conservancy engineering and geotechnical engineering protection technology, specifically to an ecological-structure-based self-healing protection structure for earth-rock dams and its construction method. Background Technology

[0002] Slope erosion refers to the phenomenon where rainfall-induced surface water flow damages the slope surface and washes away the topsoil. In earth-rock dam slopes, riverbanks, coastlines, and canal slopes, erosion is one of the main hazards leading to engineering failures. To effectively prevent slope erosion, existing slope protection methods mainly include the following typical schemes:

[0003] 1) Rigid slope protection: For example, covering the slope surface with concrete slabs, masonry, etc. Although this method has strong erosion resistance, it is expensive, impermeable, damages the ecological environment of the slope, and has poor adaptability, and is easily damaged by uneven settlement of the foundation.

[0004] 2) Rockfill or gabion slope protection: It resists erosion through the self-weight and interlocking action of the stones. However, its overall integrity is poor. Under the action of high-speed water flow or waves, the stones are easily eroded and require frequent maintenance.

[0005] 3) Turf slope protection: It has the advantages of being eco-friendly and low-cost. However, on steep slopes or in high-flow-velocity conditions, the turf and its shallow root system are easily stripped away by the water flow, resulting in limited erosion resistance.

[0006] 4) Turf and anchor combination slope protection: Anchors are used to improve the connection strength between the turf and the slope, but the core protection body is still the turf and shallow soil, which has limited ability to resist the direct scouring of the slope by water flow.

[0007] In recent years, researchers have used a combination of turf, gabions, and anchors for slope protection. However, this approach is structurally complex, the presence of gabion mesh may restrict the natural development of plant roots, and the metal mesh poses a risk of corrosion, making it unsuitable for long-term protection. Furthermore, researchers are now using composite materials for slope reinforcement, such as the Anchored Reinforced Vegetation System (ARVS), which combines High Performance Vegetation Protective Blanket (HPTRM) with Impact Driven Earth Surface Anchors (PDEA) to achieve better erosion resistance.

[0008] However, ARVS relies on synthetic materials (HPTRM) to provide surface impact resistance and reinforcement, which suffers from drawbacks such as material aging and poor integration with vegetation roots. Therefore, there is an urgent need in the field of slope protection for a new slope protection technology that can provide strong immediate impact resistance, long-term stability, eco-friendliness, and cost-effectiveness.

[0009] No effective solutions have yet been proposed to address the problems in the relevant technologies. Summary of the Invention

[0010] To address the problems in related technologies, this invention proposes an eco-structure-based self-healing protective structure for earth-rock dams and its construction method, in order to overcome the aforementioned technical problems existing in the current related technologies.

[0011] Therefore, the specific technical solution adopted by the present invention is as follows:

[0012] According to a first aspect of the present invention, an eco-structure-based self-healing protective structure for earth-rock dams is provided, disposed on the surface of the dam slope, comprising:

[0013] The rockfill layer is laid on the surface of the dam slope and consists of a root anchoring layer, a root penetrating layer and a hydraulic drainage layer laid from top to bottom. The average particle size, laying thickness and interlocking density of the rocks in each layer of the rockfill layer are dynamically calculated and determined by the layered particle size adaptive ratio optimization algorithm according to the hydraulic and geological conditions of different areas of the dam slope.

[0014] The deep-rooted turf protective layer is laid on the surface of the rockfill layer. The deep-rooted turf protective layer consists of topsoil laid on the surface of the root anchoring layer and deep-rooted plants planted on the topsoil. The roots of the deep-rooted plants penetrate through the rockfill layer and wrap around the boulders while penetrating into the surface soil of the dam slope, forming a bio-gabion structure in which the roots wrap around the rockfill.

[0015] Furthermore, the average particle size, paving thickness, and interlocking density of the boulders in each layer of the rockfill are dynamically calculated and determined by a layered particle size adaptive proportioning optimization algorithm based on the hydraulic and geological conditions of different areas of the dam slope, including:

[0016] The dam slope surface is divided into several grid units of preset specifications, and the topographic, hydraulic, geological and material parameters of each grid unit are obtained;

[0017] Based on the functions of the root anchoring layer, root penetrating layer, and hydraulic drainage layer, objective functions are established respectively. The objective functions include minimizing the soil loss rate of the root anchoring layer, maximizing the porosity of the root penetrating layer, and maximizing the seepage drainage efficiency of the hydraulic drainage layer.

[0018] The constraints are: stone particle size, paving thickness, interlocking density, root growth space, and cost.

[0019] A non-dominated sorting genetic algorithm with an elitist strategy was used to solve the quantization objective function, and the optimal average stone size, paving thickness and interlocking density of the three-layer riprap in each grid cell were obtained.

[0020] Furthermore, based on the design flow velocity, critical shear stress of the topsoil, average particle size of the root anchoring layer stones, paving thickness of the root anchoring layer, shielding coefficient, erosion coefficient, and power exponent, an objective function is constructed to minimize the topsoil loss rate of the root anchoring layer.

[0021] Furthermore, based on the average particle size, porosity, and pore throat coefficient of the root penetration layer, an objective function is constructed to maximize the porosity of the root penetration layer.

[0022] Furthermore, based on the average particle size, porosity, kinematic viscosity of water, and particle shape coefficient of the hydraulic drainage layer, an objective function is constructed to maximize the seepage drainage efficiency of the hydraulic drainage layer.

[0023] Furthermore, deep-rooted plants include herbaceous plants and shrubs;

[0024] Among them, herbaceous plants include at least one of vetiver grass, bahia grass, reed, reed shoots, sedge grass, five-jointed miscanthus, and alfalfa;

[0025] Shrubs include at least one of Lespedeza, Amorpha fruticosa, Caragana korshinskii, Hippophae rhamnoides, and Vitex negundo.

[0026] Furthermore, several anchor rods are vertically installed on the surface of the rockfill layer, with the bottom end of the anchor rod penetrating the rockfill layer and anchored in the dam slope, and a connector is installed at the top of the anchor rod on the surface of the rockfill layer.

[0027] Furthermore, the anchor bolt is an impact-driven ground anchor, and the connector is any one of geogrid, metal mesh, or flexible rope.

[0028] According to a second aspect of the present invention, a construction method for a self-healing protective structure for an earth-rock dam based on an eco-structure is provided, comprising:

[0029] The slope surface of the dam to be protected shall be modified and compacted.

[0030] Based on the hydraulic and geological conditions of different areas of the dam slope, the average particle size, paving thickness and interlocking density of the boulders in the root anchoring layer, root penetrating layer and hydraulic drainage layer are determined by combining the layered particle size adaptive ratio optimization algorithm.

[0031] Based on the average particle size, paving thickness and interlocking density of the boulders in the hydraulic drainage layer, the hydraulic drainage layer is laid on the treated dam slope surface.

[0032] Based on the average particle size, paving thickness and interlocking density of the pebbles in the root penetration layer, the root penetration layer is laid on the surface of the hydraulic drainage layer.

[0033] Based on the average particle size, paving thickness and interlocking density of the boulders in the root anchoring layer, a root anchoring layer is laid on the surface of the root penetration layer to complete the paving of the riprap layer.

[0034] Topsoil is laid on the surface of the completed rockfill layer, and seedlings of deep-rooted plants are planted or seeds of deep-rooted plants are sprayed on the topsoil according to the preset spacing.

[0035] The deep-rooted plants are maintained to promote root growth until they wrap around the stones and penetrate the rock pile layer, forming a biological gabion structure in which the roots wrap around the stones. The deep-rooted plants and the imported soil together constitute a deep-rooted turf protective layer.

[0036] Furthermore, before laying topsoil on the surface of the rockfill layer, the process includes: evenly distributing anchor points at preset intervals on the surface of the rockfill layer, driving anchor rods into the dam slope at the anchor points, and simultaneously laying connectors on the surface of the rockfill layer to fix the connectors to the top of the anchor rods.

[0037] The beneficial effects of this invention are as follows:

[0038] 1) The self-healing protective structure for earth-rock dams provided by this invention has a synergistic and enhanced scour resistance. The loosely stacked rockfill layers instantly disperse and reduce the impact energy of water flow, preventing direct scour of the slope soil while providing a root growth channel. Through the continuous growth of deep-rooted plants, the roots wrap and connect the originally loose stones to form a flexible and self-healing "biological gabion," achieving a transformation from passive scour resistance to active reinforcement and anchoring.

[0039] 2) The deep-rooted plant of this invention can form a network of hundreds to thousands of roots per plant, with a root penetration depth of ≥1.5 meters and high tensile strength. Its reinforcement and anchoring effect on the rockfill and soil significantly enhances the integrity of the protective layer and slope, improving resistance to sliding and settlement. After a long growth period of 12 months, comparative experiments showed that the erosion resistance of the experimental group of this invention was 4.2 times that of a bare slope, significantly higher than that using only the root-soil composite (2.8 times) and the traditional ARVS system (3.1 times). Simultaneously, the soil cohesion of the experimental group increased by 127.3% and the internal friction angle increased by 18.6% compared to the pure rockfill layer, indicating excellent overall stability.

[0040] 3) Based on the hydraulic and geological conditions of different areas of the dam slope, this invention uses a layered particle size adaptive ratio optimization algorithm to determine the average particle size, paving thickness, and interlocking density of the boulders in each layer of the rockfill. This allows for the automatic calculation of the optimal combination of boulder particle size and paving thickness that balances erosion prevention, root protection, drainage, and cost, taking into account the hydraulic and geological differences in different areas of the dam slope. This enables the optimization of the slope protection structure from empirical ratios to precise multi-objective adaptation, thereby maximizing root growth while ensuring erosion resistance and forming a stable and efficient biological gabion structure.

[0041] 4) This invention divides the rockfill layer into three layers, each using a stacked structure of stones with different particle size distributions. This is a refined optimization that balances the biological characteristics of the root system with the mechanical stability of the rockfill. The upper root anchoring layer has a smaller particle size to facilitate early root growth and penetration. The middle root penetration layer has a larger particle size to provide growth and envelopment space for the thickened roots. The lower hydraulic drainage layer has a particle size between the two layers to better connect with the dam slope soil and achieve drainage and filtration.

[0042] 5) The reinforcement scheme adopted in this invention completely abandons artificial synthetic materials. Unlike the existing anchored reinforced vegetation system (ARVS) which relies on high-performance vegetation protection blanket (HPTRM), this invention uses natural riprap as the surface erosion-resistant structure. The roots directly wrap around the stones to form a biological gabion, which completely eliminates the need for artificial synthetic reinforcement materials and avoids problems such as material aging and environmental pollution.

[0043] 6) The dam slope protection structure designed in this invention is permeable to water and air, which is conducive to slope stability and plant growth, and improves the ecological environment of the dam slope.

[0044] 7) This invention uses deep-rooted plant roots as biological reinforcement material. The roots themselves continuously grow and self-renew, and even if minor damage occurs locally, they can self-repair to a certain extent. Compared with purely rigid structures and composite structures that rely on artificial synthetic materials, it has lower maintenance costs and better life cycle costs.

[0045] 8) The construction process provided by this invention is simple, requires no large-scale specialized equipment, and uses common materials such as riprap and turf. Anchoring systems represented by PDEA can be installed quickly and bear load immediately, further shortening the construction period and making them easy to promote and apply in a wide range of areas. Attached Figure Description

[0046] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments 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.

[0047] Figure 1 This is a schematic diagram of the self-healing protection structure of the earth-rock dam based on the ecological structure according to Embodiment 1 of the present invention;

[0048] Figure 2 This is a schematic diagram of the root-rock encapsulation structure in the self-healing protection structure of the earth-rock dam based on the ecological-structure according to Embodiment 1 of the present invention;

[0049] Figure 3This is a schematic diagram of the self-healing protection structure of the earth-rock dam based on the ecological structure according to Embodiment 2 of the present invention;

[0050] Figure 4 This is a physical image of the self-healing protective structure of the earth-rock dam based on the ecological structure obtained in Embodiment 3 of the present invention.

[0051] In the picture:

[0052] 1. Dam slope; 2. Rockfill layer; 3. Deep-rooted turf protective layer; 4. Anchor bolts; 5. Connectors. Detailed Implementation

[0053] To further illustrate the various embodiments, the present invention provides accompanying drawings, which are part of the disclosure of the present invention. These drawings are mainly used to illustrate the embodiments and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these drawings, those skilled in the art should be able to understand other possible implementation methods and the advantages of the present invention. The components in the drawings are not drawn to scale, and similar component symbols are generally used to represent similar components.

[0054] Example 1

[0055] like Figures 1-2 As shown, according to an embodiment of the present invention, an eco-structure-based self-healing protection structure for earth-rock dams is disposed on the surface of dam slope 1. The self-healing protection structure for earth-rock dams includes:

[0056] The rockfill layer 2 is laid on the surface of the dam slope 1. The rockfill layer 2 consists of a root fixation layer, a root penetration layer and a hydraulic drainage layer laid from top to bottom. The average particle size, laying thickness and interlocking density of the rocks in each layer of the rockfill layer 2 are dynamically calculated and determined by the layered particle size adaptive ratio optimization algorithm according to the hydraulic and geological conditions of different areas of the dam slope.

[0057] The deep-rooted turf protective layer 3 is laid on the surface of the rockfill layer 2. The deep-rooted turf protective layer 3 consists of topsoil laid on the surface of the root fixation layer and deep-rooted plants planted on the topsoil. The roots of the deep-rooted plants penetrate through the rockfill layer 2 and wrap around the boulders while penetrating into the surface soil of the dam slope 1, forming a bio-gabion structure in which the roots wrap around the boulders.

[0058] In this embodiment, high-strength, weather-resistant stones are selected, and the stones are stacked in an interlocking manner. Preferably, the stone pile layer adopts a graded and layered stacking structure, and the roots of deep-rooted plants grow downward through the gaps between adjacent stones.

[0059] In the root anchoring layer, the average particle size of the boulders is 8-15cm. This layer is located 0-15cm below the bottom of the deep-rooted turf protection layer, providing a foothold for the young roots of deep-rooted plants and guiding them to grow vertically downwards. In the root penetration layer, the average particle size of the boulders is 15-30cm, located 15-40cm below the bottom of the deep-rooted turf protection layer. This provides sufficient vertical growth space for the roots, and the roots also form an interlocking structure by wrapping the boulders. In the hydraulic drainage layer, the average particle size of the boulders is 10-20cm, located 40-60cm below the bottom of the deep-rooted turf protection layer. This layer is used for drainage at the bottom of the rockfill layer to prevent water accumulation and softening. At the same time, some of the strong roots of the deep-rooted plants can continue to grow downwards and penetrate into the dam slope, playing an anchoring role.

[0060] To ensure that the deep-rooted plants selected in this embodiment can penetrate the rockfill layer and continue to penetrate into the soil of the dam slope 1, the root depth of the plants is greater than or equal to 1.5 meters.

[0061] Specifically, deep-rooted plants include herbaceous plants and shrubs; herbaceous plants include vetiver, bahiagrass, reeds, rush, miscanthus, five-jointed miscanthus, and alfalfa; shrubs include lespedeza, purple locust, caragana, sea buckthorn, and vitex. For herbaceous plants, a topsoil depth of 5-10 cm can be selected, while for larger shrubs, a topsoil depth of 10-15 cm can be selected.

[0062] The root depth and applicable areas of the above-mentioned herbaceous plants are shown in Table 1 below.

[0063] Table 1. Root depth and applicable areas of herbaceous plants

[0064] The root depth and applicable areas of shrubs are shown in Table 2 below.

[0065] Table 2 Root depth and applicable areas of shrubs

[0066] In practice, the selection and cultivation of deep-rooted plants can be flexibly chosen according to the geographical conditions of the construction area, and are not limited to the above-mentioned plant species.

[0067] In this embodiment, deep-rooted plants are selected as the traditional artificial reinforcing material (such as gabion mesh). The roots of the deep-rooted plants can penetrate the rockfill layer 2 and completely wrap around the surrounding stones, forming a stable organic-inorganic composite whole, thus constituting a natural biological gabion composite structure (such as...). Figure 2As shown, the rockfill layer 2 provides immediate physical erosion resistance against water flow shear forces. The deep-rooted plants, with their long, deep root systems, reinforce and anchor the rockfill layer 2 and the underlying dam slope 1, greatly enhancing the structure's integrity and long-term stability. They also possess self-healing capabilities. In contrast, the stability of traditional synthetic gabions decreases significantly with age, eventually becoming completely ineffective after a certain period. Using only traditional turf for dam slope greening is limited to beautifying the environment and conserving surface soil and water; it cannot form a similar bio-gabion composite structure and has very limited effectiveness in slope protection.

[0068] In this embodiment, based on the hydraulic and geological conditions of different areas of the dam slope, a layered particle size adaptive proportioning optimization algorithm is used to determine the average particle size, paving thickness, and interlocking density of each layer of rockfill in rockfill layer 2, including:

[0069] Step 1: Divide the dam slope surface into several grid units of preset specifications, and obtain the topographic, hydraulic, geological and material parameters of each grid unit;

[0070] Specifically, when the grid unit specifications are dynamically determined, the principle of "densifying the grid in areas of drastic hydraulic changes and loosening the grid in areas of gentle changes" is followed. That is, the main area of ​​the conventional dam slope adopts a 2m×2m standard grid unit; the slope shoulder, slope toe, water level fluctuation area, and both sides of the spillway, where the velocity gradient is >0.5m / s / m, adopt a 1m×1m densified grid; and large homogeneous dam slopes with a length >100m can adopt a 3m×3m loosened grid.

[0071] Spatial interpolation is performed on the collected raw data to generate a parameter raster map for each grid cell, ensuring that the parameter uniformity error within each cell is less than 10%.

[0072] Step 2: Based on the functions of the root anchoring layer, root penetrating layer, and hydraulic drainage layer, establish objective functions for each layer. The objective functions include minimizing the soil loss rate of the root anchoring layer, maximizing the porosity of the root penetrating layer, and maximizing the seepage drainage efficiency of the hydraulic drainage layer.

[0073] Specifically, based on the design flow velocity, critical shear stress of the imported soil, average particle size of the boulders in the root anchoring layer, thickness of the root anchoring layer, shielding coefficient, erosion coefficient, and power exponent, an objective function is constructed to minimize the rate of imported soil loss from the root anchoring layer. The expression is as follows:

[0074] ;

[0075] In the formula, F1 is the rate of soil loss from the root anchorage layer, and k e The erosion coefficient (in this embodiment, the loam coefficient is 0.015 t / (m²)) is used. 2•a), take 0.022 for sandy loam and 0.009 for clay. For water flow shear stress, For the critical shear stress of the soil, when ≤ At that time, no erosion of the imported soil occurred, and the rate of imported soil loss was 0. The critical shear stress of the soil is (in this embodiment, 0.5 is taken for loam, 0.3 for sandy loam, and 1.0 for clay). is the power exponent (in this embodiment, the slope flow erosion is taken as 1.8), and f is the Darcy-Weisbach friction coefficient (in this embodiment, the value is taken as 0.03~0.05). Let ρ be the water density and v be the design flow velocity. The shielding coefficient is 0.6 to 0.8 for angular stones and 0.4 to 0.6 for round stones in this embodiment. d1 is the average particle size of the stones in the root anchoring layer and h1 is the paving thickness of the root anchoring layer.

[0076] Specifically, based on the average particle size, porosity, and pore throat coefficient of the boulders in the root penetration layer, an objective function is constructed to maximize the porosity of the root penetration layer, expressed as:

[0077] ;

[0078] In the formula, F2 is the porosity of the root penetration layer, and n2 is the porosity of the root penetration layer. d1 is the pore throat coefficient (0.2 for angular stones and 0.15 for round stones in this embodiment), d2 is the average particle size of the stones in the root penetration layer, and d3 is the average particle size of the stones in the root penetration layer. root It represents the average diameter of the main penetrating roots in the mature stage of deep-rooted plants.

[0079] Specifically, based on the average particle size, porosity, kinematic viscosity of water, and particle shape coefficient of the hydraulically conductive layer, an objective function is constructed to maximize the seepage conduction efficiency of the hydraulically conductive layer, and its expression is:

[0080] ;

[0081] In the formula, F3 is the seepage conduction efficiency of the hydraulic conduction layer, and C k is the particle shape coefficient (in this embodiment, 0.0056 is taken for angular stones and 0.0039 for round stones), and g is the acceleration due to gravity. The kinematic viscosity of water (in this embodiment, it is taken as 1.004 × 10⁻⁶ at 20°C). -6 m 2 / s), d3 is the average particle size of the boulders in the hydraulic dredging layer, and n3 is the porosity of the hydraulic dredging layer.

[0082] Step 3: Constraints are imposed on the size of the stone blocks, the thickness of the paving, the density of the interlocking, the space for root growth, and the cost.

[0083] Specifically, the size constraint of the stone particles:

[0084] ;

[0085] Pavement thickness constraints:

[0086] ;

[0087] In the formula, h1, h2, and h3 are the paving thicknesses (in meters) of the root anchoring layer, root penetration layer, and hydraulic conduction layer, respectively. 1, min h 1, max h represents the minimum and maximum thickness of the root anchorage layer, respectively. 2, min h 2, max h represents the minimum and maximum thickness of the root penetration layer, respectively. 3, min h 3, max These represent the minimum and maximum thicknesses of the hydraulic drainage layer, respectively.

[0088] Interlocking density constraint (expressed as porosity):

[0089] ;

[0090] In the formula, Let b be the chimerism density of the b-th layer, and b = 1, 2, 3. denoted as the density of the stone, and n1, n2, and n3 are the porosities of the root anchoring layer, the root penetrating layer, and the hydraulically conductive layer, respectively.

[0091] Root growth space constraints:

[0092] ;

[0093] Cost constraints:

[0094]

[0095] In the formula, c m C represents the price per unit volume of the stone. max This represents the upper limit of the budget per unit area.

[0096] Step 4: Use a non-dominated sorting genetic algorithm with an elite strategy to solve the quantization objective function and obtain the optimal average stone size, paving thickness and interlocking density of the three-layer riprap for each grid cell.

[0097] Specifically, the coding method is as follows: real number coding is adopted, and each individual represents a three-layer rockfill parameter combination of a grid cell, with a total of 9 decision variables, each variable taking values ​​within its constraint range;

[0098] Algorithm parameter settings: Population size 100~200 (adjusted according to the size of the dam slope), crossover probability 0.9 (simulated binary crossover SBX), mutation probability 1 / 9 (polynomial mutation, i.e., the mutation probability of each decision variable is 1 / 9), maximum number of iterations 100~200 generations;

[0099] Initial population generation: Randomly generate N individuals as the initial population;

[0100] Fitness function: The fitness values ​​are directly used as the values ​​of the three objective functions;

[0101] Genetic operations include selection (using tournament selection, randomly selecting k individuals from the population, and choosing the individual with the best fitness as the parent, with k recommended to be 2), crossover (using simulated binary crossover), and mutation (using polynomial mutation).

[0102] Non-dominated ranking and elite preservation: The parent and offspring populations are merged to form a mixed population of size 2N; the mixed population is ranked non-dominated to obtain non-dominated frontiers of different levels; the crowding degree of individuals in each frontier is calculated; N individuals are selected in order of non-dominated level from high to low and crowding degree from large to small to form the next generation population.

[0103] Termination condition: The algorithm terminates when either of the following conditions is met: the preset maximum number of iterations is reached or the average rate of change of the objective function value over 20 consecutive Pareto fronts is less than 1%;

[0104] Optimal solution selection method: The analytic hierarchy process (AHP) is used to select the comprehensive optimal solution from the Pareto solution set, construct a judgment matrix, and determine the weights of the three objective functions (0.4 for scour resistance, 0.3 for root growth, and 0.3 for seepage conduction in this embodiment); calculate the comprehensive score of each Pareto solution; and select the solution with the highest score as the final design parameter.

[0105] Output requirements: The algorithm should output the optimal average particle size, paving thickness, and interlocking density of the three-layer riprap for each grid cell.

[0106] Example 2

[0107] like Figure 3As shown, according to an embodiment of the present invention, the self-healing protection structure of the earth-rock dam based on the ecological structure is provided with an anchoring device in addition to the structure of embodiment 1, in order to address scenarios with stronger water scouring or poor dam slope stability. The anchoring device includes an anchor rod 4 and a connector 5. The anchor rod 4 passes through the rockfill layer 2 and is anchored in the dam slope 1. The connector 5 is laid on the surface of the rockfill layer 2 and connected to the top of the anchor rod 4.

[0108] Specifically, the anchor bolt 4 is an impact-driven ground anchor; the connector 5 is any one of geogrid, metal mesh or flexible rope.

[0109] By adding anchoring devices, the overall stability of the protective structure can be increased during the early growth of deep-rooted plants, while connector 5 can also provide a medium for the roots of deep-rooted plants to climb.

[0110] Example 3

[0111] A construction method for a self-healing protective structure for earth-rock dams based on ecological structure includes:

[0112] S1. Repair the slope surface of the dam to be protected, remove obstacles, and compact it to form a flat construction base surface;

[0113] S2. Based on the hydraulic and geological conditions of different areas of the dam slope, the average particle size, paving thickness and interlocking density of the boulders in the root fixation layer, root penetration layer and hydraulic drainage layer are determined by the layered particle size adaptive ratio optimization algorithm.

[0114] S3. Based on the average particle size, paving thickness and interlocking density of the hydraulic drainage layer, lay the hydraulic drainage layer on the treated dam slope.

[0115] S4. Based on the average particle size, paving thickness and interlocking density of the boulders in the root penetration layer, lay the root penetration layer on the surface of the hydraulic drainage layer.

[0116] S5. Based on the average particle size, paving thickness and interlocking density of the boulders in the root anchoring layer, lay the root anchoring layer on the surface of the root penetration layer to complete the laying of the riprap layer.

[0117] Specifically, the stones in each layer are laid manually or mechanically, and the stones are loosely piled up layer by layer from the foot of the slope to the top of the slope, so that the stones are interlocked with each other, but there are enough gaps to allow the roots of deep-rooted plants to grow downward through the gaps between adjacent stones.

[0118] S6. Lay topsoil (a mixture of loam, organic fertilizer, and water-retaining agent) on the surface of the completed rockfill layer, and plant seedlings of deep-rooted plants or spray seeds of deep-rooted plants on the topsoil according to the preset spacing.

[0119] S7. Maintain deep-rooted plants by watering and fertilizing them regularly to promote root growth until they wrap around the stones and penetrate the rock pile layer, forming a biological gabion structure with roots wrapping around the stones. The deep-rooted plants and the imported soil together constitute a deep-rooted turf protective layer.

[0120] like Figure 4 The image shown is a physical diagram of the self-healing protective structure of the earth-rock dam based on the ecological structure obtained in this embodiment.

[0121] The following describes a specific implementation scenario using vetiver as an example. Experiments were conducted at a test site in a certain province. A single vetiver plant can form hundreds to thousands of roots with a diameter of 0.6-2.2 mm, penetrating to a depth of 2-3 meters (5-6 meters at its deepest point). The tensile strength of a single root can reach 14.4-2000 MPa, making it an ideal experimental subject. In this embodiment, 15-30 cm diameter stones are selected and artificially piled to form a stone layer approximately 40 cm thick. The topsoil layer is 5-10 cm thick. Vetiver seedlings are planted in the topsoil at 30 cm intervals using a hole-planting method. The stone layer laid in this invention is not densely piled like traditional mortar-grouted or dry-laid stone masonry. Instead, the stones form a stable framework through point or surface contact, retaining obvious pores to meet the needs of root growth. This embodiment takes granite blocks as an example. The uniformity coefficient of the blocks is 2.5-3.5. The gradation is controlled to ensure porosity. The dry density of the pile is 1.65-1.75 g / cm³, and the porosity is 35%±3%, which meets the requirements of loose piling and leaves a channel for root growth.

[0122] Specifically, the construction method for the hydraulic drainage layer (lower layer) is as follows: Granite boulders with a particle size of 10-20cm are selected, and the porosity is controlled between 35% and 40%. The lower layer of boulders, approximately 20cm thick, is loosely piled onto the undisturbed soil surface of the dam slope. The main function of this layer is to quickly divert water that has seeped into the rockfill layer to the toe of the slope, preventing the slope soil from softening due to prolonged soaking.

[0123] The construction method for the root penetration layer (middle layer) is as follows: Use stones with a particle size of 15-30cm, controlling the porosity between 30%-35%, with a thickness of approximately 25cm. This layer is the core load-bearing layer. The high surface roughness of the granite enhances the interfacial friction coefficient between the roots and the stones. The stones are loosely stacked, allowing for some gaps between them to facilitate the later thickening of the roots through and wrapping around the roots.

[0124] The construction method for the root anchorage layer (upper layer) is as follows: Select small to medium-sized stones with a particle size of 8-15cm, control the porosity between 40% and 50%, and the thickness is about 15cm. This layer is in direct contact with the topsoil, and the surface of the stones can be moderately roughened to provide more physical anchor points for early root attachment. After paving, lay a 5-10cm thick layer of vegetative soil on top, and plant vetiver seedlings in holes at 30cm×30cm intervals.

[0125] Maintenance and inspection: Regularly check whether the connection between each layer is tight, and whether there are areas where the particle size jump is too large, which may cause the root system to be obstructed. If so, fill the area with medium-sized stones to form a transition.

[0126] Measurements were taken after three months of maintenance. The vetiver root network had enveloped the surrounding boulders and penetrated the rockfill layer into the dam slope soil. After six months of maintenance, the vetiver root network, having completely penetrated the rockfill layer, continued to penetrate the dam slope soil to a depth of over 1 meter, completely enveloping the surrounding boulders. This indicates that the structure has formed a robust bio-gabion composite. After a flood season, the slope section using this implementation scheme remained intact, with lush turf growth and no signs of any boulders being washed away. In contrast, the traditional dry-laid stone slope protection scheme in the same section showed localized loosening and subsidence of stones after the flood season. This fully demonstrates the superior erosion resistance and overall stability of the dam slope erosion protection structure provided by this invention.

[0127] To further verify the erosion resistance of the above-mentioned root-rock bio-gabion composite structure, the following comparative test was designed in this embodiment: five experimental groups were set up, and the contents of each group scheme are shown in Table 3 below.

[0128] Table 3. Protocol details for the five experimental groups

[0129] Each experimental group used a detachable steel test chamber of the same size, with permeable holes at the bottom to simulate drainage conditions on an actual slope. Five samples were prepared for each experimental group, for a total of 25 test samples, to ensure the accuracy of subsequent test data. Furthermore, each experimental group containing vegetation underwent continuous maintenance, while groups without vegetation were tested directly. The Anchored Reinforced Vegetation System (ARVS), relying on a combination of High Performance Vegetation Protective Blanket (HPTRM) and Impact Driven Ground Anchor (PDEA), is a superior synthetic material reinforced slope protection solution in the existing technology. To fully demonstrate the long-term effectiveness of this invention, a control experiment was conducted 12 months after vegetation growth.

[0130] The soil used in the experiment was taken from the undisturbed soil of the slope of the proposed protective dam. Its basic physical and mechanical properties are shown in Table 4 below:

[0131] Table 4 Basic Physical and Mechanical Indicators

[0132] The specific testing method for scour resistance performance included: using a variable-slope scour flume with a length of 5 meters, a width of 0.5 meters, and a slope of 30° for scour resistance testing. The water flow velocity gradient was set to 0.5 m / s, 1.0 m / s, 1.5 m / s, 2.0 m / s, 2.5 m / s, and 3.0 m / s, covering a range from low to high velocity. Each velocity gradient was used for scour for 60 minutes. Water samples were collected from the scour outlet every 10 minutes to determine the sediment content. Finally, the average cumulative scour volume for each group within 60 minutes was calculated. After the scour test, the shear strength of each treatment group was determined using a strain-controlled direct shear apparatus, and root parameters were measured using the WinRHIZO root analysis system.

[0133] The experimental results are shown in Table 5 below:

[0134] Table 5 Experimental Results

[0135] The experimental results showed that after 12 months of growth, the erosion resistance of the experimental group was 4.2 times that of the bare slope, significantly higher than that of control group 3 (root-soil composite, 2.8 times) and control group 4 (ARVS, 3.1 times). Direct shear tests showed that the cohesion of the experimental group increased by 127.3% and the internal friction angle increased by 18.6% compared to the rockfill layer, indicating that the "biological gabion" formed by the roots wrapping the stones has excellent overall stability. Root analysis showed that the vetiver roots had completely penetrated the rockfill layer, reaching an average depth of 1.2m into the lower soil, and forming a dense network within the rockfill layer, tightly wrapping the stones.

[0136] Therefore, this embodiment demonstrates that by combining the roots of deep-rooted plants with a rockfill layer to form a bio-gabion structure, a significant improvement in impact resistance can be achieved without any synthetic reinforcement materials. This avoids issues such as material aging and environmental pollution. Furthermore, after six months of growth and the formation of a complete bio-gabion structure, the structure still exhibits remarkable stability after a full 12-month growth cycle. This demonstrates both the promoting effect of the loosely stacked rockfill layer on plant growth and the superiority of deep-rooted plant roots as a bio-reinforcing material. Because the roots continuously grow and self-renew, the system can self-repair to a certain extent even if minor damage occurs locally. Compared to purely rigid structures and composite structures relying on synthetic materials, it has lower maintenance costs and a more favorable life-cycle cost.

[0137] Example 4

[0138] A construction method for a self-healing protective structure for earth-rock dams based on ecological structure, this embodiment adds the following steps to embodiment 3:

[0139] The impact-driven ground anchor (PDEA) system was used as the anchoring device in this embodiment. After the rockfill layer was laid, anchor points were arranged in a staggered pattern at 2m x 2m intervals. The anchor points were positioned to avoid subsequent vetiver planting holes, ensuring sufficient space for root growth. A handheld impact hammer was used to drive the PDEA anchor rod into the soil at a 15° angle to the slope normal, with an anchoring depth of 2.5m, ensuring the anchor head entered the stable bearing layer. After reaching the design depth, the drive rod was withdrawn, and the anchor head automatically flipped to a horizontal position to form a pull-out bearing mechanism. A pull-out test was performed after each anchor point was installed to verify that the bearing capacity met the design requirements. After the anchor rod was pulled out of the rockfill layer surface, a bidirectional geogrid was laid on the rockfill layer surface. The anchor cable and the geogrid were securely connected with stainless steel clips, and a pretension of 10% of the design load was applied to ensure a tight fit between the geogrid and the rockfill layer. Subsequent vetiver planting and maintenance were the same as in Embodiment 3. The PDEA anchoring system provides immediate anchoring before the vetiver root system is fully developed (approximately 3-6 months). Once the root system is mature, the root network and PDEA together form a three-dimensional reinforced structure. The anchor cables penetrate the rockfill layer, guiding the root growth direction and promoting the organic integration of the root system and the anchoring system. This embodiment demonstrates that even with the same anchoring system for additional reinforcement, the overall construction process of this invention is simpler, requiring no large-scale specialized equipment. Anchoring systems like PDEA can be installed quickly and provide immediate load-bearing capacity, further shortening the construction period and facilitating widespread application.

[0140] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "setting," "connection," "fixing," "screw connection," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components or the interaction between two components. Unless otherwise explicitly limited, those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0141] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A self-healing protective structure for an earth-rock dam based on an ecological-structure, disposed on the surface of the dam slope (1), characterized in that, include: The rockfill layer (2) is laid on the surface of the dam slope (1), and the rockfill layer (2) consists of a root fixation layer, a root penetration layer and a hydraulic drainage layer laid from top to bottom. The average particle size, laying thickness and interlocking density of the rocks in each layer of the rockfill layer (2) are dynamically calculated and determined by the layered particle size adaptive ratio optimization algorithm according to the hydraulic and geological conditions of different areas of the dam slope. A deep-rooted turf protective layer (3) is laid on the surface of the rock pile layer (2), and the deep-rooted turf protective layer (3) is composed of imported soil laid on the surface of the root fixation layer and deep-rooted plants planted on the imported soil. The roots of the deep-rooted plants penetrate through the rock pile layer (2) and wrap around the boulders while penetrating into the surface soil of the dam slope (1), forming a biological gabion structure in which the roots wrap around the boulders.

2. The self-healing protective structure for earth-rock dams based on ecological structure according to claim 1, characterized in that, The average particle size, paving thickness, and interlocking density of the boulders in each layer of the rockfill layer (2) are dynamically calculated and determined by a layered particle size adaptive ratio optimization algorithm based on the hydraulic and geological conditions of different areas of the dam slope, including: The dam slope surface is divided into several grid units of preset specifications, and the topographic, hydraulic, geological and material parameters of each grid unit are obtained; Based on the functions of the root anchoring layer, root penetrating layer, and hydraulic drainage layer, objective functions are established respectively. The objective functions include minimizing the soil loss rate of the root anchoring layer, maximizing the porosity of the root penetrating layer, and maximizing the seepage drainage efficiency of the hydraulic drainage layer. The constraints are: stone particle size, paving thickness, interlocking density, root growth space, and cost. A non-dominated sorting genetic algorithm with an elitist strategy was used to solve the quantization objective function, and the optimal average stone size, paving thickness and interlocking density of the three-layer riprap in each grid cell were obtained.

3. The self-healing protective structure for earth-rock dams based on ecological structure according to claim 2, characterized in that, Based on the design flow velocity, critical shear stress of the topsoil, average particle size of the root anchoring layer stones, paving thickness of the root anchoring layer, shielding coefficient, erosion coefficient, and power exponent, an objective function is constructed to minimize the topsoil loss rate of the root anchoring layer.

4. The self-healing protective structure for earth-rock dams based on ecological structure according to claim 2, characterized in that, Based on the average particle size, porosity, and pore throat coefficient of the root penetration layer, an objective function is constructed to maximize the porosity of the root penetration layer.

5. The self-healing protective structure for earth-rock dams based on ecological structure according to claim 2, characterized in that, Based on the average particle size, porosity, kinematic viscosity of water, and particle shape coefficient of the hydraulic drainage layer, an objective function is constructed to maximize the seepage drainage efficiency of the hydraulic drainage layer.

6. The self-healing protective structure for earth-rock dams based on ecological structure according to claim 1, characterized in that, The deep-rooted plants include herbaceous plants and shrubs; The herbaceous plants include at least one of the following: vetiver, bahia grass, reed, arundinaria, sedge, five-jointed miscanthus, and alfalfa. The shrubs include at least one of Lespedeza, Amorpha fruticosa, Caragana korshinskii, Hippophae rhamnoides, and Vitex negundo.

7. The self-healing protective structure for earth-rock dams based on ecological structure according to claim 1, characterized in that, The surface of the rockfill layer (2) is provided with several anchor rods (4) vertically downward, and the bottom end of the anchor rod (4) penetrates the rockfill layer (2) and is anchored in the dam slope (1). The top end of the anchor rod (4) and located on the surface of the rockfill layer (2) is provided with a connector (5).

8. The self-healing protective structure for earth-rock dams based on ecological structure according to claim 7, characterized in that, The anchor rod (4) is an impact-driven ground anchor, and the connector (5) is any one of geogrid, metal mesh or flexible rope.

9. A construction method for a self-healing protective structure for earth-rock dams based on ecological structure, characterized in that, include: The slope surface of the dam to be protected shall be modified and compacted. Based on the hydraulic and geological conditions of different areas of the dam slope, the average particle size, paving thickness and interlocking density of the boulders in the root anchoring layer, root penetrating layer and hydraulic drainage layer are determined by combining the layered particle size adaptive ratio optimization algorithm. Based on the average particle size, paving thickness and interlocking density of the boulders in the hydraulic drainage layer, the hydraulic drainage layer is laid on the treated dam slope surface. Based on the average particle size, paving thickness and interlocking density of the pebbles in the root penetration layer, the root penetration layer is laid on the surface of the hydraulic drainage layer. Based on the average particle size, paving thickness and interlocking density of the boulders in the root anchoring layer, a root anchoring layer is laid on the surface of the root penetration layer to complete the paving of the riprap layer. Topsoil is laid on the surface of the completed rockfill layer, and seedlings of deep-rooted plants are planted or seeds of deep-rooted plants are sprayed on the topsoil according to the preset spacing. The deep-rooted plants are maintained to promote root growth until they wrap around the stones and penetrate the rock pile layer, forming a biological gabion structure in which the roots wrap around the stones. The deep-rooted plants and the imported soil together constitute a deep-rooted turf protective layer.

10. The construction method of a self-healing protective structure for an earth-rock dam based on ecological structure according to claim 9, characterized in that, Before laying topsoil on the surface of the rockfill layer, the following also includes: Anchor points are evenly distributed on the surface of the rockfill layer at a predetermined interval, and anchor rods are driven into the dam slope at the anchor points. At the same time, connectors are laid on the surface of the rockfill layer and fixed to the top of the anchor rods.

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