Self-repairing fluidized solidified soil reinforced retaining wall for slope toe reinforcement and construction method

Abstract

The application relates to a self-repairing fluid-solidified soil reinforced retaining wall for slope toe reinforcement and a construction method, wherein the retaining wall comprises: a wall body, which is formed by in-situ pouring of self-repairing fluid-solidified soil and is provided with two side extension sections, and drainage holes are arranged in the extension sections; a foundation, which is arranged on the foundation and is used for supporting the wall body; and a reinforcement system, which is composed of multiple layers of geogrids and is buried in the wall body in layers, one end of each layer of geogrid is anchored in the wall body, and the other end extends backward and is anchored in the backfill area. When the retaining wall appears microcracks due to uneven settlement of the soft foundation, the high-alkali environment at the cracks can immediately trigger the rupture of alkali-sensitive self-repairing microcapsules, and the released repair material can generate a gel to seal the cracks in situ. This mechanism changes the traditional passive damage into active repair, effectively restrains the development of cracks, blocks the erosion channel, and significantly improves the long-term durability of the retaining wall.

Description

Technical Field

[0001] This invention relates to the field of engineering construction technology, and specifically to a self-healing fluidized solidified soil reinforced retaining wall and its construction method for slope toe reinforcement. Background Technology

[0002] In the construction of infrastructure such as highways, railways, and water conservancy projects, slope excavation is often required when traversing soft soil areas to form roadbeds or site slabs. Soft soil is characterized by low bearing capacity, high compressibility, and poor permeability. Under such geological conditions, slope cutting and the construction of retaining structures is a complex and challenging engineering problem. The core issues can be summarized in three aspects: First, slope cutting disrupts the stress balance of the original slope, creating an open surface. Under its own weight, the slope generates a huge downward thrust pointing towards the open surface, posing a severe test to any retaining structure. Second, soft soil foundations are prone to uneven settlement under the load of the superstructure, which may lead to cracking of the rigid retaining wall structure. Third, surface runoff from rainfall and groundwater from the slope will accumulate in the backfill area behind the wall, generating hydrostatic pressure and seepage force that are detrimental to the stability of the retaining wall.

[0003] In existing technologies, reinforced soil retaining walls, as an effective form of support, bear earth pressure through the friction between the reinforcing material embedded in the backfill and the soil. They are widely used due to their good seismic performance and foundation adaptability. In terms of materials, in order to utilize engineering waste soil and save resources, fluidized solidified soil technology has also been tried in retaining wall construction. It uses a solidifying agent to modify the waste soil into a material with fluidity and a certain strength. In terms of drainage, the common practice is to pre-install drainage holes in the wall to drain water accumulated behind the wall.

[0004] However, existing technologies still have at least the following significant shortcomings: traditional concrete or fluidized solidified soil are brittle materials; when uneven settlement occurs in soft foundations, tensile stress will be generated inside the retaining wall, which will lead to structural cracks. Once cracks are generated, they will not only continue to develop and weaken the overall structure, but also become channels for moisture and corrosive media to penetrate, accelerating the corrosion of internal reinforcement and material deterioration, posing a serious threat to the long-term durability and safety of the structure. Summary of the Invention

[0005] The purpose of this invention is to overcome the defects of the prior art and provide a self-healing fluidized solidified soil reinforced retaining wall and construction method for slope toe reinforcement, solving the problem that the retaining wall is prone to cracking and the damage is irreversible, affecting its durability.

[0006] To achieve the above objectives, the present invention provides a self-healing, fluidized solidified soil reinforced retaining wall for slope toe reinforcement, which is constructed on a foundation and has a backfill area behind it. The retaining wall includes: The wall body is cast on-site from self-healing fluidized solidified soil and has two side extensions with drainage holes in the extensions. The foundation, set on the ground, is used to support the wall body. The reinforcement system consists of multiple layers of geogrid, which are embedded in the wall body in layers. One end of each layer of geogrid is anchored in the wall body, and the other end extends backward and is anchored in the backfill area. The drainage system includes drainage holes opened in the extension section and multiple layers of drainage strips laid in the backfill area, wherein the drainage holes are connected to the corresponding drainage strips. The self-healing fluidized solidified soil contains alkali-sensitive self-healing microcapsules. When cracks appear in the wall body, the alkali-sensitive self-healing microcapsules can rupture in response to the alkaline environment, releasing repair material to seal the cracks.

[0007] By adopting this technical solution, the alkali-sensitive self-healing microcapsules in the self-healing fluidized solidified soil endow the material with intelligent repair capabilities. Specifically, when the retaining wall develops microcracks due to uneven settlement of the soft foundation, the high-alkali environment at the crack can immediately trigger the rupture of the alkali-sensitive self-healing microcapsules. The released repair material can generate gel in situ to seal the cracks. This mechanism transforms the traditional passive damage into active repair, effectively curbing crack development and blocking erosion channels, thereby significantly improving the long-term durability of the retaining wall and directly solving the problem of easy cracking and irreversible damage in retaining wall structures. The layered and anchored reinforcement system provides the retaining wall with excellent tensile strength, greatly improves the stress mode of the structure, prevents the wall body from bulging and sliding as a whole, and solves the problem of insufficient deformation resistance. The drainage system design, which places drainage holes in the extension section and connects them to the drainage strip behind the wall, separates the drainage function from the main load-bearing wall, avoids stress concentration and strength reduction caused by opening holes in the load-bearing main body, preserves the structural integrity of the wall, and ensures the long-term reliability of drainage efficiency through a three-dimensional drainage network. It also eliminates the hidden danger of water pressure increase due to drainage failure and resolves the contradiction between drainage efficiency and structural integrity.

[0008] Furthermore, the substrate of the self-healing fluidized solidified soil comprises engineering waste soil, a composite curing agent, and mixing water; wherein, The composite curing agent is composed of ordinary silicate cement, slag powder and silica fume; The shell of the alkali-sensitive self-healing microcapsule is hydroxypropyl methylcellulose phthalate, and the core material contains lithium silicate and nano-silica sol.

[0009] By adopting this technical solution, ordinary silicate cement provides early strength and the critical high-alkali environment; slag powder contributes to later strength and durability; silica fume achieves ultra-fine filling and significantly improves density; the three work together to form a dense, high-strength, and high-alkali matrix, which is not only a guarantee of strength, but also a prerequisite for triggering the self-healing function of alkali-sensitive self-healing microcapsules. The shell material ensures that cracking only occurs in the high-alkaline environment at the cracks in the wall body, achieving precise triggering; the core material combination can efficiently react with the matrix to generate CSH gel, ensuring the repair effect.

[0010] Furthermore, the reinforcement system is arranged in three zones along the wall height direction: a bottom reinforcement zone, a middle transition zone, and a top conventional zone. The spacing between geogrid layers in the bottom densified zone is smaller than that in the middle transition zone, and the spacing between geogrid layers in the middle transition zone is smaller than that in the top conventional zone.

[0011] By adopting this technical solution, the zoning is specified as bottom reinforcement, middle transition, and top regular, so that the strength of the reinforcement material is precisely deployed in the bottom area of ​​the retaining wall where the soil pressure is the greatest, thereby maximizing the stability against bulging and sliding in the most economical way.

[0012] Furthermore, the drainage system consists of a multi-layered drainage structure; Each layer of the drainage structure includes a drainage strip laid within the backfill area and drainage holes connected to it, located within the extension section; wherein, The drainage structure at the bottom layer is arranged horizontally, while the drainage structure above the bottom layer is arranged at an angle. The angle of the drainage structure corresponds to the position of the interface between different permeable soil layers in the backfill area.

[0013] By adopting this technical solution, the multi-layer drainage structure forms a three-dimensional drainage network. The inclined drainage strips are more likely to guide water flow and can effectively intercept and drain water from soil layers with different permeability. This can solve the problems of easy failure of single drainage paths and inability to effectively control the water level of soil layers at different depths.

[0014] This invention also provides a construction method for a self-healing fluidized solidified soil reinforced retaining wall for slope toe reinforcement, comprising the following steps: S1. Foundation treatment and surveying / layout; S2. Preparation of self-healing fluidized solidified soil: Engineering waste soil, composite solidifying agent and mixing water are mixed to form a matrix, and then alkali-sensitive self-healing microcapsules are added by low-speed post-mixing method. S3. Construction of the substructure; S4. Layered synchronous construction of the wall body and reinforcement system: Starting from the top surface of the foundation, the formwork is erected in a cycle from bottom to top, the self-healing fluidized solidified soil is poured, the geogrid is laid before initial setting and ensured to be covered, and drainage holes are pre-embedded in the wall extension section. S5. Simultaneously construct the wall reinforcement and anchoring system and drainage system: Backfill the slag and soil in layers behind the wall body, and simultaneously perform the following operations: When the excavated soil is backfilled to the elevation of the geogrid, it is unfolded and anchored in the backfill soil; When the excavated soil is backfilled to the design elevation of the drainage strip, a drainage strip connected to the drainage holes is constructed.

[0015] Furthermore, the low-speed post-mixing method in step S2 is as follows: the speed of the mixer used to mix the engineering waste soil, composite curing agent and mixing water is reduced, and then the alkali-sensitive self-healing microcapsules are blown into the matrix through negative pressure airflow, and then mixing continues.

[0016] By adopting this technical solution, the low-speed post-doping method can effectively protect the fragile alkali-sensitive self-healing microcapsules from being damaged during the stirring process, ensuring that their repair function is preserved.

[0017] The laying of geogrid in step S4 includes: The wall is divided into three zones along its height: a bottom encrypted zone, a middle transition zone, and a top regular zone. When setting up templates and pouring self-healing fluidized solidified soil for each zone, the geogrid should be laid in layers before the self-healing fluidized solidified soil initially sets.

[0018] Furthermore, the construction of the drainage strip in step S5 includes: when backfilling to the interface of different permeable soil layers, shaping the backfill surface into an inclined slope, laying geocells and filling them with graded crushed stone.

[0019] By adopting this technical solution, the drainage effect is guaranteed.

[0020] Compared with the prior art, the present invention has the following advantages: 1. The alkali-sensitive self-healing microcapsules in self-healing fluidized solidified soil endow the material with intelligent repair capabilities. Specifically, when microcracks appear in the retaining wall due to uneven settlement of the soft foundation, the high-alkali environment at the crack can immediately trigger the rupture of the alkali-sensitive self-healing microcapsules. The released repair material can generate gel in situ to seal the cracks. This mechanism transforms the traditional passive damage into active repair, effectively curbing crack development and blocking erosion channels, thereby significantly improving the long-term durability of the retaining wall and directly solving the problem of easy cracking and irreversible damage in retaining wall structures.

[0021] 2. The layered and anchored reinforcement system provides the retaining wall with excellent tensile strength, greatly improves the stress pattern of the structure, prevents the wall body from bulging and slipping as a whole, and solves the problem of insufficient deformation resistance.

[0022] 3. The drainage system design, in which drainage holes are located in the extension section and connected to the drainage strip behind the wall, separates the drainage function from the main load-bearing wall, avoiding stress concentration and strength reduction caused by opening holes in the load-bearing main body, preserving the structural integrity of the wall, and ensuring the long-term reliability of drainage efficiency through a three-dimensional drainage network, eliminating the hidden danger of water pressure increase due to drainage failure, and resolving the contradiction between drainage efficiency and structural integrity.

[0023] 4. The retaining wall reinforcement system is divided into zones: bottom reinforcement, middle transition, and top conventional. This ensures that the reinforcement material is precisely deployed in the bottom area of ​​the retaining wall where soil pressure is greatest, maximizing the stability against bulging and sliding in the most economical way. Attached Figure Description

[0024] Figure 1 This is a top view of the self-healing fluidized solidified soil reinforced retaining wall used for slope toe reinforcement in this invention. Figure 2 for Figure 1 Schematic diagram of the sectional view along the central AA direction; Figure 3 for Figure 1 Schematic diagram of the BB-direction section; Figure 4 This is a front view schematic diagram of the self-healing fluidized solidified soil reinforced retaining wall used for slope toe reinforcement in this invention.

[0025] Explanation of reference numerals in the attached drawings: 1. Wall body; 2. Foundation; 3. Extension section; 4. Backfill area; 5. Drainage hole; 6. Drainage strip; 7. Geogrid. Detailed Implementation

[0026] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0027] Please see the appendix Figure 1 , 2 4. This invention provides a self-healing, fluidized solidified soil reinforced retaining wall for slope toe reinforcement, which is constructed on a foundation and has a backfill area 4 behind it; the retaining wall consists of a wall body 1, a foundation 2, a reinforcement system, and a drainage system; wherein: The wall body 1 is cast on site from self-healing fluidized solidified soil. Its top width is not less than 0.8m. The wall body 1 includes a main section and two extension sections 3 on both sides. The cross section of the main section is trapezoidal. The cross section of the extension section 3 is rectangular and has the same width as the top of the wall. The length of the extension section 3 is w2, 0.7m≤w2≤1.2m. Drainage holes 5 are opened inside the extension section 3. Foundation 2 is set on a compacted and leveled foundation, and its width is greater than the bottom width of the wall body 1. The two sides of foundation 2 are flush with the edges of extension section 3. The reinforcement system consists of multiple layers of geogrid 7, which are embedded in the wall body 1 in layers. One end of each layer of geogrid 7 is anchored in the wall body 1, and the other end extends backward and is anchored in the backfill area 4. The drainage system includes drainage holes 5 opened in the extension section 3 and multiple drainage strips 6 laid in the backfill area 4, wherein the drainage holes 5 are connected to the corresponding drainage strips 6. The self-healing fluidized solidified soil contains alkali-sensitive self-healing microcapsules. When cracks appear in the wall body 1, the alkali-sensitive self-healing microcapsules can rupture in response to an alkaline environment, releasing repair material to seal the cracks.

[0028] The self-healing fluidized solidified soil preparation material consists of a substrate and externally incorporated alkali-sensitive self-healing microcapsules; wherein... The substrate is composed of 100 parts by weight of engineering waste soil, 8 parts by weight of composite curing agent and 28 parts by weight of mixing water; the maximum particle size of the engineering waste soil is no more than 10 mm and the moisture content is no more than 15%; the composite curing agent is composed of 4 parts of ordinary Portland cement, 3.2 parts of S95 grade granulated blast furnace slag powder and 0.8 parts of silica fume. Among them, ordinary Portland cement provides early strength and initial alkalinity, slag powder contributes to later strength growth and durability, and silica fume rapidly consumes Ca(OH)2 and achieves ultrafine filling. The three work together to form a dense, high-strength, and high-alkali matrix microstructure.

[0029] The reaction mechanism of ordinary silicate cement lies in the rapid hydration reaction of its core minerals, tricalcium silicate (C3S) and dicalcium silicate (C2S), with water to generate hydrated calcium silicate (CSH) gel and calcium hydroxide (Ca(OH)2), which are the main sources of strength. This process can be represented as follows: C3S + H2O → CS-H + Ca(OH)2 (rapid) C2S + H2O → CS-H + Ca(OH)2 (slow and continuous) The generated Ca(OH)2 stabilizes the pH value of the material pore solution above 12.5, which not only provides the necessary alkaline activation conditions for the pozzolanic reaction of slag powder and silica fume, but also serves as a key environment for triggering the rupture of self-healing microcapsules. The reaction mechanism of S95 grade granulated blast furnace slag powder is as follows: Under the alkaline activation of cement hydration product Ca(OH)2, the active SiO2 and Al2O3 contained therein undergo a secondary hydration reaction (volcanic ash reaction) to generate secondary CSH gel with a low calcium-to-silicon ratio and hydrated calcium aluminate (CAH). This process is represented as follows: SiO2 + Ca(OH)2 + H2O → CSH Al₂O₃ + Ca(OH)₂ + H₂O → CAH The gel produced in this process is denser and can effectively fill the capillary pores left by cement hydration, significantly reducing the permeability of the material and contributing to its later strength. The reaction mechanism of silica fume is as follows: its extremely high specific surface area and amorphous SiO2 content give it both physical filling and chemical activity. Physically, the nano-sized silica fume particles (about 0.1 μm) can fill the micron- and submicron-sized pores between cement and slag particles, achieving optimized particle size distribution. Chemically, it undergoes a vigorous pozzolanic reaction with Ca(OH)2 to generate high-density CSH gel, which further refines the pore size distribution and significantly improves the early strength and impermeability of the material.

[0030] Alkali-sensitive self-healing microcapsules are externally doped at a volume ratio of 0.8% to 2.0%. The shell of the alkali-sensitive self-healing microcapsules is alkali-sensitive hydroxypropyl methylcellulose phthalate (HPMCP), and the core material is a mixture of 30% lithium silicate aqueous solution and nano-silica sol with a particle size of about 20 nm at a mass ratio of 2.5:1. The average particle size of the alkali-sensitive self-healing microcapsules is 120~180μm, and the shell thickness is 13~17μm.

[0031] The function of alkali-sensitive self-healing microcapsules is to trigger the shell swelling and rupture when the pH of the pore solution of the self-healing fluidized solidified soil exceeds 12 and microcracks appear, and release the core material to gel in situ within the crack to generate CSH gel bands, thereby achieving self-healing and re-bonding of cracks during service life. The triggering and rupture process of the shell HPMCP is as follows: the phthalate groups in the HPMCP molecular chain undergo hydrolysis in a highly alkaline environment (pH>12) to generate carboxylate (HPMCP + OH-). － →Carboxylate + alcohol), hydrolysis causes the polymer chain to carry a negative charge and generate electrostatic repulsion. At the same time, the hydrophilicity of the molecules increases, causing the shell to absorb a large amount of water from the surrounding environment and swell. When the swelling degree exceeds its mechanical strength limit, the shell will rupture under the stress at the crack tip or the action of internal osmotic pressure. A shell thickness of 13-17 μm is sufficient to maintain stability throughout the material's service life, resisting physical wear during mixing and curing processes. Simultaneously, it can complete the OH- curing process within 10-30 minutes when the pH of the pore solution exceeds 12. － Ion diffusion induces sufficient swelling until rupture; The reaction process of each component in the core material mixture is as follows: a 30% lithium silicate aqueous solution provides a high concentration of highly reactive soluble silicate ions (H2SiO4). 2- ) and lithium ion (Li + ), which, along with the Ca released from the matrix at the crack, 2+ Rapid reaction to form CSH gel (H2SiO4) 2- +Ca 2+ +2H₂O→CS⁻H⁺2H⁺ + ); at the same time, Li + It can accelerate the hydration of residual cement particles and further promote the formation of gel network; nano-silica sol provides solid nano-SiO2 particles with high specific surface area, whose surface silanol groups (Si-OH) can react with Ca(OH)2 to form CSH gel, which serves as a supplement and enhancement to the lithium silicate reaction, providing a continuous and stable gelation effect; in addition, lithium silicate and nano-silica sol can ensure that non-penetrating microcracks with a width of no more than 0.10 mm are effectively sealed to a non-connected seepage state within 24 to 72 hours; The alkali-sensitive self-healing microcapsules have an average particle size of 120~180μm, which matches the scale of common microcracks in materials. This ensures that a sufficient number of microcapsules are distributed along the crack path without negatively affecting the homogeneity and strength of the matrix.

[0032] Furthermore, the alkali-sensitive self-healing microcapsules were prepared using a coaxial sharp-hole coagulation bath method. This method involves using a core material mixture as the inner phase fluid and an 8% (w / w) HPMC solution dissolved in a 1:1 volume ratio of ethanol and acetone as the outer phase fluid. The inner and outer phase fluids are combined to form uniform core-shell droplets through a coaxial sharp-hole device at a constant peristaltic pump flow rate. These droplets are then dropped into a 2% (w / w) polyvinyl alcohol (PVA) aqueous solution coagulation bath. The microcapsules are then washed with deionized water to remove residual solvent and PVA, followed by vacuum drying at 35°C for 12 hours to remove moisture without causing thermal degradation or rupture of the shell. Finally, the finished alkali-sensitive self-healing microcapsules with a particle size of 125–175 μm are obtained through sieving, with a sealing rate of no less than 90%. When the core-shell droplet enters the coagulation bath, the organic solvents (ethanol and acetone) in the outer phase rapidly diffuse into the aqueous phase (PVA solution), causing the solubility of HPMCP in the organic phase to decrease sharply and phase separation to occur. As a result, the core material droplet precipitates, solidifies, and solidifies into a shell around the core material droplet. PVA, as a surfactant and stabilizer, is adsorbed at the droplet interface, which can reduce interfacial tension, prevent droplet coalescence, and control the particle size distribution of the final alkali-sensitive self-healing microcapsules. During the drying process, the gentle temperature rise and vacuum environment created by vacuum drying at 35℃ for 12 hours allow the residual solvent and moisture in the shell to evaporate slowly and evenly, avoiding the formation of micropores or cracks due to vapor pressure inside the shell caused by rapid evaporation of surface moisture, thus ensuring the product's seal rate.

[0033] Please see the appendix Figure 3 The reinforcement system consisting of multi-layer geogrid 7 is arranged in zones along the wall height, following the zoning principle of "bottom densification - middle transition - top conventional": The visible height of the retaining wall from the top surface of foundation 2 to the top of the wall is taken as... H The first layer of geogrid 7 is installed above the top surface of foundation 2. e At point 0, 0.10m ≤ e 0≤0.15m; Vertical clearance between the top layer of geogrid 7 and the top of the wall e t ≤0.15m; The boundaries of each zone and the spacing between layers are as follows: The vertical range of the bottom encryption area is 0~0.35. H Interlayer spacing Δ h 1 = 0.20~0.25m; The vertical range of the central transition zone is 0.35. H ~0.75 H Interlayer spacing Δ h 2 = 0.25~0.30m; The vertical range of the top regular area is 0.75. H ~ H Interlayer spacing Δ h 3 = 0.30~0.40m; The maximum spacing between any two adjacent layers of geogrid 7 shall not exceed 0.40m; The embedment length of each layer of grille within the wall body 1 l 1≥0.30m, and l 1. Not less than 0.4 times the width of the top of the wall; the free anchorage length of each layer of grid extending into the backfill area 4 behind the wall. l The value of partition 2 is: bottom encrypted area l 2≥max(0.60 H (2.0m), central transition zone l 2≥max(0.50 H (1.8m), top regular area l 2≥max(0.40 H (1.5m) The initial laying distance of each layer of geogrid 7 from the side of the wall is: S , 0.1m≤ S ≤0.15m, to prevent corrosion from exposure at the 7 ends of the geogrid; The length of geogrid 7 within the same zone should be consistent, and its length should be uniformly set according to the length of the lowest soil layer geogrid within the zone.

[0034] Furthermore, the portion of the geogrid 7 extending outside the wall body 1 is laid horizontally in the backfilled slag area behind the wall and anchored to the compacted slag body using U-shaped anchors. For each layer of geogrid 7, the horizontal and longitudinal anchoring spacing of the U-shaped anchors does not exceed 0.5m.

[0035] Furthermore, the total number and allocation of the reinforcing system layers of the retaining wall meet the following layout plan: Total number of floors n According to the average interlayer spacing Δ h The value is determined to be between 0.25 and 0.35 m. n ≥ H / Δ h ,and n No less than 6 floors; The bottom encrypted zone accounts for 45% to 60% of the total number of layers, the middle transition zone accounts for 25% to 40%, and the top regular zone accounts for 15% to 25%.

[0036] Please see the appendix Figure 1-2 The drainage holes 5 in the extension section 3 are connected to the drainage strip 6 in the backfill area 4 behind the retaining wall, together forming a drainage structure; the drainage structure has multiple layers, forming a drainage system. Drainage strip 6 is composed of graded crushed stone filled in the geocell chamber, and is continuously laid along the three sides of the backfill area 4 that do not contact the retaining wall, with a thickness of [missing information]. d 0.3m≤ d ≤0.5m, laying width is w 1, 0.3m≤ w 1≤0.5m, with thickness and width consistent with the drainage channel inside extension section 3; The drainage system consists of a multi-layered drainage structure. Each layer comprises a drainage strip 6 and drainage holes 5 connected to it. The drainage strip 6 and drainage holes 5 of the bottom layer are flush with the top of the retaining wall foundation 2 and are arranged horizontally. The drainage strips 6 and drainage holes 5 above the bottom layer are arranged at an angle of inclination. θ 5°≤ θ ≤10°; The number of drainage structure layers depends on the permeability coefficient of the slope soil. k Based on borehole exposure and sampling tests, the general classification from bottom to top can be as follows: 1) Soils with extremely low permeability, such as clay and dense silt. k <10 -6 cm / s; 2) Low-permeability soils, such as silty clay and silt, 10 -6cm / s≤ k <10 -4 cm / s; 3) Moderately permeable soils, such as silt and fine sand, 10 -4 cm / s≤ k <10 -2 cm / s; 4) Highly permeable soils, such as sand and gravel. k ≥10 -2 cm / s; After dividing the soil layers according to the order of magnitude of the permeability, inclined drainage structures need to be set between adjacent soil layers.

[0037] Referring to 1-4, corresponding to the self-healing fluidized solidified soil reinforced retaining wall for slope toe reinforcement, this invention also provides a construction method for a self-healing fluidized solidified soil reinforced retaining wall for slope toe reinforcement, specifically including the following steps: S1. Foundation treatment and surveying / layout; The foundation soil of the retaining wall was leveled and compacted; the wall height was determined based on the survey and design data. H Vertical position of the first layer geogrid 7 e 0. Topmost clear distance e t Spacing Δ between each zone h 1. Δ h 2. Δ h 3. Length embedded in the wall l 1 and the length of free anchorage behind the wall l 2. Determine the length of extension segment 3. w 2. Drainage strip thickness 6 d With width w 1. Inclination angle θ And the alignment relationship of drainage holes 5 and drainage strips 6 in each layer; lay out the outline of foundation 2, wall body 1 (main section and extension section 3), elevation and boundary line of geogrid 7 in each layer, and position of drainage holes 5 and drainage strips 6 in each layer on site.

[0038] S2, Preparation of fluidized solidified soil; According to the design ratio, a self-healing fluidized solidified soil is prepared for use using a low-speed post-mixing method. The specific steps are as follows: 1) Matrix mixing: Add the engineering waste soil and composite curing agent into the mixer, dry mix for 120 seconds, then add mixing water and wet mix for 180 seconds to form a uniform fluidized solidified soil matrix; 2) Alkali-sensitive self-healing microcapsules blending: Reduce the mixer speed to 15-20 rpm, and use a dedicated negative pressure airflow conveyor with a venturi tube to blow the metered alkali-sensitive self-healing microcapsules evenly and slowly into the mixer within 60 seconds. Then continue mixing for another 60 seconds before discharging. This method can control the mixing breakage rate of alkali-sensitive self-healing microcapsules to below 3%.

[0039] S3, Foundation 2 construction; Erect foundation formwork 2 and pour concrete to form foundation 2.

[0040] S4. The wall body 1 and the reinforcement system are constructed simultaneously. Numbered from bottom to top, layer 1 is the bottom layer, and layer n is the top layer; the height of the i-th layer of geogrid 7 from the bottom of the wall is... Z i The distance between adjacent layers is defined as Δ h i = Z i - Z i－1 ( i ≥2), starting from the top surface of foundation 2, construct in layers from bottom to top in a cyclical manner: a) First-floor wall pouring: After foundation 2 is poured and reaches the demolding strength, the first-floor wall is constructed in the sequence of formwork erection, pouring, and first-floor grid laying. The formwork height of the first-floor wall is Δ h 1' is consistent with the pouring height, that is e 0, and at this time Z 1= e 0; b) Erecting inter-layer formwork: Construction of the first... i layer( i When ≥2), the template height Δ h i '=Δ h i +0.5·Δ h i－1 ; c) Pouring and Vibration: Pouring self-healing fluidized solidified soil into the formwork up to the specified depth. i layer( i ≥2) Top surface elevation, and moderate vibration; d) Laying geogrid 7: Before the self-healing fluidized solidified soil poured in this layer initially sets, lay the cut geogrid 7 horizontally, flatten and straighten it; then continue to pour a self-healing fluidized solidified soil slurry covering layer of not less than 50mm thick on the geogrid 7 and vibrate it so that the ribs of the geogrid 7 are completely wrapped without any through cavities. e) Reserved drainage hole 5: When the pouring reaches the elevation of the drainage structure, a pre-embedded pipe is inserted at the corresponding position of the extension section 3 to form a drainage hole 5 channel, and the hole direction is consistent with the direction of its corresponding drainage strip 6. f) Layer by layer, the template is raised and steps b) to e) are repeated until the top layer of geogrid 7 is laid and the wall body 1 is poured as a whole.

[0041] S5. Construction of backfill and drainage system behind the wall; After the wall body 1 reaches the predetermined strength, the backfilling operation of the slag behind the wall will be carried out: 1) Construction of the bottom drainage strip 6: Lay a horizontal drainage strip 6 at the bottom of the backfill area 4 and fill it with graded crushed stone to ensure smooth communication with the inner opening of the pre-embedded drainage hole 5 in the wall extension section 3. 2) Layered backfilling of slag: Backfill the slag behind the wall in layers, with each layer being 0.4~0.6m thick, and compact it simultaneously, with a compaction degree of not less than 95%; 3) Simultaneous laying and anchoring of geogrid 7: During the backfilling process, whenever the backfill surface reaches the elevation of a certain layer of pre-laid geogrid 7, the portion of the geogrid 7 in the backfill area 4 is unfolded, straightened, and immediately anchored in the compacted slag soil using U-shaped anchors at the designed spacing. 4) Construct a drainage system simultaneously: At the interface of different permeable soil layers, lay inclined drainage strips 6 simultaneously with backfilling. The specific procedures are as follows: a) Shaping the inclined base surface: When the backfill soil reaches the bottom elevation of the designed drainage strip 6, the compacted backfill soil surface is trimmed to the designed inclination angle with the drainage strip 6. θ A uniformly sloping surface; b) Laying and filling: Geocells are laid on the sloping surface and filled with graded crushed stone to form an inclined drainage strip 6 that meets the design requirements; c) Interface connection: Ensure smooth connection between the drainage strip 6 and the inner opening of the pre-embedded drainage hole 5 in the wall extension section 3.

[0042] S6. Maintenance and Acceptance; The molded structure should be properly maintained, and quality inspection and acceptance should be carried out after it reaches the design age.

[0043] It should be noted that in the above specific embodiments of the construction methods for the self-healing fluidized solidified soil reinforced retaining wall for slope toe reinforcement and the self-healing fluidized solidified soil reinforced retaining wall for slope toe reinforcement, the parameters involved in the two are corresponding. In the actual operation of the construction method, the construction and control are carried out according to the parameter design of the retaining wall.

[0044] The present invention has been described in detail above with reference to the accompanying drawings and embodiments. Those skilled in the art can make various modifications to the present invention based on the above description. Therefore, certain details in the embodiments should not be construed as limiting the present invention, and the scope of protection of the present invention shall be defined by the appended claims.

Claims

1. A self-healing, fluidized solidified soil reinforced retaining wall for slope toe reinforcement, constructed on a foundation and having a backfill area behind it, characterized in that, The retaining wall includes: The wall body is cast on-site from self-healing fluidized solidified soil and has two side extensions with drainage holes in the extensions. The foundation, set on the ground, is used to support the wall body. The reinforcement system consists of multiple layers of geogrid, which are embedded in the wall body in layers. One end of each geogrid layer is anchored in the wall body, and the other end extends backward and is anchored in the backfill area. The reinforcement system is arranged along the wall height and divided into three zones: a bottom dense zone, a middle transition zone, and a top conventional zone. The geogrid layer spacing in the bottom dense zone is smaller than that in the middle transition zone, and the geogrid layer spacing in the middle transition zone is smaller than that in the top conventional zone. The drainage system includes drainage holes opened within the extension section and multiple layers of drainage strips laid within the backfill area. The drainage holes are connected to the corresponding drainage strips. The drainage system consists of multiple drainage structures. Each layer of the drainage structure includes a drainage strip laid within the backfill area and drainage holes opened within the extension section that are connected to it. The bottom layer of the drainage structure is horizontally arranged, while the drainage structures above the bottom layer are inclined. The inclined arrangement of the drainage structures corresponds to the change position of the interfaces between different permeable soil layers within the backfill area. The drainage strip is composed of graded crushed stone filled in the geocell chamber and is continuously laid along the three sides of the backfill area that do not contact the retaining wall. Its thickness and width are consistent with the drainage channels within the extension section. The self-healing fluidized solidified soil contains alkali-sensitive self-healing microcapsules. When cracks appear in the wall body, the alkali-sensitive self-healing microcapsules can rupture in response to the alkaline environment, releasing repair material to seal the cracks.

2. The self-healing fluidized solidified soil reinforced retaining wall for slope toe reinforcement according to claim 1, characterized in that, The substrate of the self-healing fluidized solidified soil comprises engineering waste soil, a composite curing agent, and mixing water; wherein, The composite curing agent is composed of ordinary silicate cement, slag powder and silica fume; The shell of the alkali-sensitive self-healing microcapsule is hydroxypropyl methylcellulose phthalate, and the core material contains lithium silicate and nano-silica sol.

3. A construction method for a self-healing, fluidized solidified soil reinforced retaining wall for slope toe reinforcement as described in any one of claims 1-2, characterized in that, Includes the following steps: S1. Foundation treatment and surveying / layout; S2. Preparation of self-healing fluidized solidified soil: Engineering waste soil, composite curing agent and mixing water are mixed to form a matrix, and then alkali-sensitive self-healing microcapsules are added using a low-speed post-addition method; the low-speed post-addition method is as follows: the speed of the mixer used to mix engineering waste soil, composite curing agent and mixing water is reduced, and then the alkali-sensitive self-healing microcapsules are blown into the matrix through negative pressure airflow, and then mixing is continued; S3. Construction of the substructure; S4. Layered synchronous construction of the wall body and reinforcement system: Starting from the top surface of the foundation, the formwork is erected in a cycle from bottom to top, the self-healing fluidized solidified soil is poured, the geogrid is laid before initial setting and ensured to be covered, and drainage holes are pre-embedded in the wall extension section. S5. Simultaneously construct the wall reinforcement and anchoring system and drainage system: Backfill the slag and soil in layers behind the wall body, and simultaneously perform the following operations: When the excavated soil is backfilled to the elevation of the geogrid, it is unfolded and anchored in the backfill soil; When the slag is backfilled to the design drainage strip elevation, a drainage strip connected to the drainage holes is constructed. The construction of the drainage strip includes: when backfilling to the interface of different permeability soil layers, the backfill surface is trimmed into an inclined slope, geocells are laid and filled with graded crushed stone.

4. The construction method of the self-healing fluidized solidified soil reinforced retaining wall for slope toe reinforcement according to claim 3, characterized in that, Step S4, laying the geogrid, includes: The wall is divided into three zones along its height: a bottom encrypted zone, a middle transition zone, and a top regular zone. When setting up templates and pouring self-healing fluidized solidified soil for each zone, the geogrid should be laid in layers before the self-healing fluidized solidified soil initially sets.

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