Gravity type ecological retaining wall added with rapid consolidation agent and construction method

Abstract

The gravity type ecological retaining wall added with the rapid consolidation agent is characterized by comprising a retaining wall body formed by compounding rubble, undisturbed soil and the rapid consolidation agent, plant seeds are evenly distributed in the retaining wall body, a vegetation layer is arranged on the top of the retaining wall body, a drainage system is arranged in the retaining wall body, and the drainage system is connected with the retaining wall body. The retaining wall body is provided with a plurality of settlement expansion joints. According to the gravity type ecological retaining wall added with the rapid consolidation agent, the bearing capacity and the soil consolidation speed can be improved, and the plant survival rate is high. The invention further discloses a construction method of the gravity type ecological retaining wall added with the rapid consolidation agent.

Description

Technical Field

[0001] This invention relates to the field of geological disaster prevention and control engineering technology, specifically to a gravity-type ecological retaining wall with added rapid consolidation agent and its construction method. Background Technology

[0002] Retaining walls are structures used to prevent slope instability. After a geological disaster, the most important thing is to ensure that the disaster does not happen again and to maintain the stability of the slope in the area. While ensuring safety, environmental protection should also be taken into account. Traditional gravity retaining walls mostly use concrete or masonry structures, which have the following defects: 1. Poor greening effect, easily forming an ecological damage zone after construction, and the rigid structure blocks surface water infiltration and the migration channels of animals and plants; 2. Slow soil consolidation speed, affecting the construction progress; 3. Inadequate drainage system leads to a decrease in structural stability; 4. Lack of systematic vegetation restoration measures, which easily causes secondary soil erosion.

[0003] Existing improvement technologies, such as vegetated concrete retaining walls, can partially restore vegetation, but still suffer from problems such as low early strength (7-day compressive strength <1MPa) and low plant survival rate (<60%). For example, the ecological retaining wall disclosed in CN109736263A uses a protective net structure, but does not solve the problem of rapid molding; the soil stabilizer in CN110408408A lacks ecological synergistic design. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the technical problem to be solved by the present invention is to provide a gravity ecological retaining wall with added fast consolidation agent that can improve bearing capacity and soil consolidation speed and plant survival rate.

[0005] Therefore, the present invention is implemented using the following technical solution: A gravity-type ecological retaining wall with added rapid consolidation agent is characterized by: a retaining wall body composed of rubble, undisturbed soil and rapid consolidation agent, plant seeds evenly distributed within the retaining wall body, a vegetation layer on top of the retaining wall body, a drainage system inside the retaining wall body, and multiple settlement expansion joints in the retaining wall body.

[0006] Furthermore, the rapid consolidating agent is an inorganic polymer consolidating agent, and its components, by mass percentage, are: 10-15% silicate cement, 5-8% high-alumina cement, 3-5% modified silica fume, 2-4% early strength agent, 0.5-1.2% water-reducing agent, and the balance being water.

[0007] Furthermore, the volume content of the rubble is 20%-30%, the compressive strength of the rubble is ≥MU30, the maximum size of the rubble does not exceed 1 / 3 of the minimum width of the casting part and is ≤300mm, the thickness of the rubble is 10-20cm, and the spacing between adjacent rubble stones is 15-25cm.

[0008] Furthermore, the drainage system includes: The retaining wall's main foundation shall have an outward drainage slope with a gradient of ≥5%. The main body of the retaining wall is equipped with a filter layer structure at the top, which is composed of alternating layers of graded crushed stone and geotextile. The retaining wall body is provided with several parallel drainage holes. The drainage holes are PVC drainage holes with a drainage slope of 5% and a horizontal spacing of 2.0m.

[0009] Furthermore, the spacing between the settlement expansion joints is 10-15m, the joint width is 20-25mm, and the inner, outer, and top sides of the settlement expansion joints are filled with asphalt-impregnated wooden boards and asphalt-impregnated hemp fibers, with a filling depth ≥150mm. Furthermore, the vegetation layer includes a tree planting area, a shrub planting area, and a climbing plant planting area. The tree planting adopts an inverted pot-shaped tree pit and a secondary settling method. The climbing plants are artificially guided to grow towards the rock slope.

[0010] Furthermore, the diameter of the tree pit in the tree planting area is 2-2.5 times the diameter of the seedling root ball, and a permeable layer is set at the bottom of the tree pit. The secondary settlement method includes the following steps: after the tree is placed upright, backfill the soil first, then flush it with water and stir it into mud with a shovel. After 10-15 minutes, the water will settle naturally. Then backfill the soil in the settlement depression, water it, and stir it slightly to make the soil density slightly less than the lower part, thus forming a second settlement.

[0011] In this invention, a composite wall structure is formed by alternately pouring rubble and soil-consolidation agent mixture. This combines rapid consolidation agent with ecological restoration technology to achieve simultaneous engineering protection and ecological restoration. The rubble content is controlled at 20-30% to form a skeleton interlocking effect, improving the overall load-bearing capacity. A special consolidation agent is used, which is composed of silicate cement, high-alumina cement, modified silica fume, early strength agent, water-reducing agent and water. The consolidation time is greatly shortened compared with traditional materials, and the compressive strength can reach 1.2-1.5MPa after 24 hours. It has both the stability of gravity structure and the deformation adaptability of flexible structure. Settlement expansion joints are set and filled with asphalt wood boards and asphalt hemp fibers to effectively absorb the stress generated by differential settlement of the foundation. Seeds are pre-buried during construction, and a stable plant community is formed in conjunction with the later planting of trees, resulting in higher vegetation coverage and survival rate.

[0012] This invention also provides a construction method for a gravity-type ecological retaining wall with the addition of a rapid consolidation agent, characterized by the following steps: (a) Excavate the foundation trench in sections, with each section having a length of ≤8m. The slope of the foundation should be corrected to 5% and the trench should be inspected. (b) Layered support formwork and pouring of original soil-consolidation agent mixed slurry and rubble filler, with a single layer thickness ≤10cm and an interlayer interval ≤2 hours; (c) Simultaneously embed PVC drainage pipes and install settlement expansion joint filling material; (d) Planting and maintaining vegetation on the top of the wall, including excavation of inverted pot-shaped tree pits, secondary settlement and planting of seedlings with soil balls, and layered backfilling of the substrate.

[0013] Furthermore, the vegetation planting includes: (1) Based on a comprehensive survey of the climate conditions, plant species adaptability, and soil properties of the survey area, select the dominant tree species suitable for the local conditions; (2) Plants should be planted in the appropriate season, the best time being spring. Plants should be selected from those that are growing well and have a full root system. (3) The pits should be dug according to the seedling positions determined by the planting site. The pit diameter should be more than twice the diameter of the soil ball. Before planting, select well-rotted organic fertilizer, mix the fertilizer with the soil, and apply it into the pit. (4) Before transporting the selected tree species, the seedlings with soil balls should be inspected and selected from nearby seedlings. The seedlings should be dug up in the evening and transported at night. The amount of pruning before planting should be 20-30% of the soil ball volume. (5) After planting, build a tree embankment and water it thoroughly within 24 hours after planting. For the first 10 days, water it daily until the substrate is saturated. (6) Climbing plants are manually pulled weekly to adjust their growth angle.

[0014] Furthermore, a two-year maintenance period will be implemented after the vegetation planting construction, including: (1) Early maintenance: After sowing grass and shrub seeds, the early maintenance (i.e., before the germination rate is 30%) mainly involves spraying water. Generally, spray once every 1 to 2 days on sunny days; (2) Spraying maintenance: The watering time is noon in winter and morning and evening in summer. During the maintenance period, different nutrient solutions should be used for different grass and shrub types for the initial maintenance after revegetation. The time is 2-5 months. Since the matrix layer of rock slope is relatively thin, the number of spraying times and the amount of spraying should be increased appropriately in the dry season. (3) Traction: During the growing season, climbing plants should be manually tractioned once a week, and overly dense branches should be pruned in winter; (4) Pest and disease control: Apply biological agents every quarter to control pests and diseases. Attached Figure Description

[0015] The present invention includes the following figures: Figure 1 This is a schematic diagram of the gravity-type ecological retaining wall in this invention; Figure 2This is a schematic diagram of the gravity-type ecological retaining wall and the surrounding planting area in this invention.

[0016] Attached diagram labels: 1. Main body of retaining wall; 2. Drainage hole; 3. Drainage slope; 4. Graded crushed stone layer; 5. Geotextile layer; 6. Tree planting area; 7. Shrub planting area; 8. Climbing plant planting area. Detailed Implementation

[0017] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided below.

[0018] Referring to the above-mentioned figures, the present invention provides a gravity-type ecological retaining wall with added rapid consolidation agent, characterized in that: it includes a retaining wall body 1 composed of rubble, undisturbed soil, and a rapid consolidation agent; plant seeds are evenly distributed within the retaining wall body 1; a vegetation layer is provided on the top of the retaining wall body 1; a drainage system is provided inside the retaining wall body 1; multiple settlement expansion joints are provided in the retaining wall body 1; and the rapid consolidation agent is an inorganic polymer consolidation agent, whose components, by mass percentage, are: 10-15% silicate cement and 5% high-alumina cement. The composition is as follows: -8%, modified silica fume 3-5%, early strength agent 2-4%, water-reducing agent 0.5-1.2%, with the balance being water. The volume content of the rubble is 20%-30%, the compressive strength of the rubble is ≥MU30, the maximum size of the rubble does not exceed 1 / 3 of the minimum width of the pouring part and is ≤300mm, the thickness of the rubble is 10-20cm, and the spacing between adjacent rubble stones is 15-25cm. The drainage system includes: an outward drainage slope 3 set at the base of the retaining wall body 1 with a slope ≥5%; a filter layer structure is provided on the top of the retaining wall body 1, the filter layer structure consisting of a graded crushed stone layer. The retaining wall is constructed by alternating layers of geotextile and geotextile. The main body of the retaining wall 1 has several parallel drainage holes 2, which are PVC drainage holes with a drainage slope of 5% and a horizontal spacing of 2.0m. The settlement expansion joints have a spacing of 10-15m and a joint width of 20-25mm. The inner, outer, and top sides of the settlement expansion joints are filled with asphalt-impregnated wood boards and asphalt-impregnated hemp fibers to a depth ≥150mm. The vegetation layer includes a tree planting area 6, a shrub planting area 7, and climbing plant species. Planting area 8, where trees are planted using inverted pot-shaped planting pits and a secondary settling method, with climbing plants being manually guided to grow towards the rock slope. The diameter of the planting pits in planting area 6 is 2-2.5 times the diameter of the seedling's root ball, and a permeable layer is set at the bottom of the planting pits. The secondary settling method includes the following steps: after the trees are placed upright, soil is backfilled first, then water is poured in and stirred into mud with a shovel. After 10-15 minutes, the water settles naturally. Then, soil is backfilled into the settling depression, watered, and stirred slightly to make the soil density slightly less than the lower part, forming a second settling.

[0019] In this embodiment, a composite wall structure is formed by alternating pouring of rubble and soil-consolidation agent mixture. This combines rapid consolidation agent with ecological restoration technology, enabling simultaneous engineering protection and ecological restoration. The rubble content is controlled at 20-30%, creating a skeletal interlocking effect to improve overall load-bearing capacity. A special consolidation agent is used, composed of silicate cement, high-alumina cement, modified silica fume, early-strength agent, water-reducing agent, and water. This agent significantly shortens the consolidation time compared to traditional materials, achieving a 24-hour compressive strength of 1.2-1.5 MPa. It combines the stability of gravity structures with the deformation adaptability of flexible structures. Settlement expansion joints are installed and filled with asphalt-impregnated wood planks and asphalt-impregnated hemp fibers to effectively absorb differential settlement of the foundation. The generated stress prevents crack expansion and extends service life. Seeds are pre-buried during construction to form a stable plant community with the later planting of trees, resulting in higher vegetation coverage and survival rate. The tree layer uses deep-rooted tree species such as camphor and Elaeocarpus decipiens, with a spacing of 2.5-3.0m. The shrub layer is planted with mesophytic plants such as Pittosporum tobira and Photinia serratifolia. Climbing plants include vertical greening species such as Ivy and Trumpet creeper. The bottom diameter of the inverted pot-shaped tree pit is 10-15cm larger than the top diameter to form a water storage space. The secondary settling method ensures that the roots are closely connected with the soil, resulting in a higher survival rate. The drainage holes 2 in the wall quickly drain internal water to prevent frost heave and seepage damage. The filter layer (graded crushed stone layer 4 + geotextile layer 5) effectively blocks the loss of fine particles.

[0020] This invention also provides a construction method for a gravity-type ecological retaining wall with the addition of a rapid consolidation agent, characterized by the following steps: (a) Excavate the foundation trench in sections, with each section having a length of ≤8m. The slope of the foundation should be corrected to 5% and the trench should be inspected. (b) Layered support formwork and pouring of original soil-consolidation agent mixed slurry and rubble filler, with a single layer thickness ≤10cm and an interlayer interval ≤2 hours; (c) Simultaneously embed PVC drainage pipes and install settlement expansion joint filling material; (d) Planting and maintaining vegetation on the top of the wall, including excavation of inverted pot-shaped tree pits, secondary settlement and planting of seedlings with soil balls, and layered backfilling of the substrate.

[0021] The vegetation planting includes: (1) Based on a comprehensive survey of the climate conditions, plant species adaptability, and soil properties of the survey area, select the dominant tree species suitable for the local conditions; (2) Plants should be planted in the appropriate season, the best time being spring. Plants should be selected from those that are growing well and have a full root system. (3) The pits should be dug according to the seedling positions determined by the planting site. The pit diameter should be more than twice the diameter of the soil ball. Before planting, select well-rotted organic fertilizer, mix the fertilizer with the soil, and apply it into the pit. (4) Before transporting the selected tree species, the seedlings with soil balls should be inspected and selected from nearby seedlings. The seedlings should be dug up in the evening and transported at night. The amount of pruning before planting should be 20-30% of the soil ball volume. (5) After planting, build a tree embankment and water it thoroughly within 24 hours after planting. For the first 10 days, water it daily until the substrate is saturated. (6) Climbing plants are manually pulled weekly to adjust their growth angle.

[0022] The vegetation planting will be followed by a two-year maintenance period, including: (1) Early maintenance: After sowing grass and shrub seeds, the early maintenance (i.e., before the germination rate is 30%) mainly involves spraying water. Generally, spray once every 1 to 2 days on sunny days; (2) Spraying maintenance: The watering time is noon in winter and morning and evening in summer. During the maintenance period, different nutrient solutions should be used for different grass and shrub types for the initial maintenance after revegetation. The time is 2-5 months. Since the matrix layer of rock slope is relatively thin, the number of spraying times and the amount of spraying should be increased appropriately in the dry season. (3) Traction: During the growing season, climbing plants should be manually tractioned once a week, and overly dense branches should be pruned in winter; (4) Pest and disease control: Apply biological agents every quarter to control pests and diseases.

[0023] In this embodiment, local virgin soil and rubble are used to reduce carbon emissions from building material transportation, thus lowering overall costs. During the two-year maintenance period, drip irrigation and manual traction are used to ensure vegetation stability, with minimal subsequent human intervention. Segmented excavation (each segment ≤ 8m) minimizes disturbance to the original slope and avoids slope instability caused by large-section excavation. Settlement expansion joints (10-15m spacing) accommodate uneven foundation settlement, making it particularly suitable for treating unstable slopes such as landslides and collapses. Construction of the retaining wall 1 is avoided during the rainy season, and vegetation planting is preferably carried out in spring, utilizing the characteristic that plant roots sprout earlier than above-ground parts to improve survival rates. Secondary settlement planting is carried out through... The combination of irrigation and layered backfilling creates a loose yet dense root anchoring layer, ensuring smooth drainage and close bonding between the seedlings and the substrate, resulting in a higher survival rate. Spring planting, combined with evening digging and overnight transportation, minimizes seedling moisture loss. During the dry season, spraying maintains substrate moisture content. Artificial guidance of vines ensures controllable climbing direction. Through the interlocking structure of rubble and soil and the anchoring effect of vegetation roots, slope anti-sliding stability and ecological function restoration are achieved simultaneously, avoiding the risk of instability in traditional rigid structures. After vegetation coverage, the retaining wall seamlessly blends with the natural landscape. Climbing plants can gradually cover the wall over time, restoring the ecology along the road and forming a natural landscape.

Claims

1. A gravity-type ecological retaining wall with added rapid consolidation agent, characterized in that: The retaining wall body is composed of rubble, undisturbed soil and a fast-consolidating agent. Plant seeds are evenly distributed inside the retaining wall body. A vegetation layer is set on the top of the retaining wall body. A drainage system is provided inside the retaining wall body. Multiple settlement expansion joints are provided in the retaining wall body.

2. A gravity-type ecological retaining wall with added rapid consolidation agent according to claim 1, characterized in that: The rapid consolidating agent is an inorganic polymer consolidating agent, and its components by mass percentage are: 10-15% silicate cement, 5-8% high alumina cement, 3-5% modified silica fume, 2-4% early strength agent, 0.5-1.2% water-reducing agent, and the balance being water.

3. A gravity-type ecological retaining wall with added rapid consolidation agent according to claim 1, characterized in that: The rubble volume content is 20%-30%, the rubble compressive strength is ≥MU30, the maximum size of the rubble does not exceed 1 / 3 of the minimum width of the casting part and is ≤300mm, the rubble thickness is 10-20cm, and the spacing between adjacent rubble stones is 15-25cm.

4. A gravity-type ecological retaining wall with added rapid consolidation agent according to claim 1, characterized in that: The drainage system includes: The retaining wall's main foundation shall have an outward drainage slope with a gradient of ≥5%. The main body of the retaining wall is equipped with a filter layer structure at the top, which is composed of alternating layers of graded crushed stone and geotextile. The retaining wall body is provided with several parallel drainage holes. The drainage holes are PVC drainage holes with a drainage slope of 5% and a horizontal spacing of 2.0m.

5. A gravity-type ecological retaining wall with added rapid consolidation agent according to claim 1, characterized in that: The settlement expansion joint has a joint spacing of 10-15m and a joint width of 20-25mm. The inner, outer, and top sides of the settlement expansion joint are filled with asphalt-impregnated wooden boards and asphalt-impregnated hemp fibers, with a filling depth of ≥150mm.

6. A gravity-type ecological retaining wall with added rapid consolidation agent according to claim 1, characterized in that: The vegetation layer includes a tree planting area, a shrub planting area, and a climbing plant planting area. The tree planting adopts the inverted pot bottom tree pit and secondary settlement method. The climbing plants are artificially guided to grow towards the rock slope.

7. A gravity-type ecological retaining wall with added rapid consolidation agent according to claim 6, characterized in that: The diameter of the tree pit in the planting area is 2-2.5 times the diameter of the seedling's root ball. A permeable layer is set at the bottom of the tree pit. The secondary settlement method includes the following steps: After the tree is placed upright, backfill the soil first, then flush it with water and stir it into mud with a shovel. After 10-15 minutes, the water will settle naturally. Then backfill the settlement depression with soil, water it, and stir it slightly to make the soil density slightly less than the bottom, thus forming a second settlement.

8. A construction method for a gravity-type ecological retaining wall with added rapid consolidation agent according to any one of claims 1-7, characterized in that: Includes the following steps: (a) Excavate the foundation trench in sections, with each section having a length of ≤8m. The slope of the foundation should be corrected to 5% and the trench should be inspected. (b) Layered support formwork and pouring of original soil-consolidation agent mixed slurry and rubble filler, with a single layer thickness ≤10cm and an interlayer interval ≤2 hours; (c) Simultaneously embed PVC drainage pipes and install settlement expansion joint filling material; (d) Planting and maintaining vegetation on the top of the wall, including excavation of inverted pot-shaped tree pits, secondary settlement and planting of seedlings with soil balls, and layered backfilling of the substrate.

9. A construction method for a gravity-type ecological retaining wall with an added rapid consolidation agent according to claim 8, characterized in that: The vegetation planting includes: (1) Based on a comprehensive survey of the climate conditions, plant species adaptability, and soil properties of the survey area, select the dominant tree species suitable for the local conditions; (2) Plants should be planted in the appropriate season, the best time being spring. Plants should be selected from those that are growing well and have a full root system. (3) The pits should be dug according to the seedling positions determined by the planting site. The pit diameter should be more than twice the diameter of the soil ball. Before planting, select well-rotted organic fertilizer, mix the fertilizer with the soil, and apply it into the pit. (4) Before transporting the selected tree species, the seedlings with soil balls should be inspected and selected from nearby seedlings. The seedlings should be dug up in the evening and transported at night. The amount of pruning before planting should be 20-30% of the soil ball volume. (5) After planting, build a tree embankment and water it thoroughly within 24 hours after planting. For the first 10 days, water it daily until the substrate is saturated. (6) Climbing plants are manually pulled weekly to adjust their growth angle.

10. A construction method for a gravity-type ecological retaining wall with an added rapid consolidation agent according to claim 9, characterized in that: The vegetation planting will be followed by a two-year maintenance period, including: (1) Early maintenance: After sowing grass and shrub seeds, the early maintenance (i.e., before the germination rate is 30%) mainly involves spraying water. Generally, spray once every 1 to 2 days on sunny days; (2) Spraying maintenance: The watering time is noon in winter and morning and evening in summer. During the maintenance period, different nutrient solutions should be used for different grass and shrub types for the initial maintenance after revegetation. The time is 2-5 months. Since the matrix layer of rock slope is relatively thin, the number of spraying times and the amount of spraying should be increased appropriately in the dry season. (3) Traction: During the growing season, climbing plants should be manually tractioned once a week, and overly dense branches should be pruned in winter; (4) Pest and disease control: Apply biological agents every quarter to control pests and diseases.

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