Construction method of ecological protection slope of loose broken soil high slope

Abstract

A construction method of loose broken soil high slope ecological protection slope, comprising the following construction steps: a, prefabricating top beam prefabricated section, top beam prefabricated node section, bottom beam prefabricated section, bottom beam prefabricated node section, longitudinal beam prefabricated section and transverse beam prefabricated section of the protection slope structure according to the design drawing, preparing the cast-in-place section formwork and the vegetation system; the protection slope structure is combined and spliced by the top beam, the transverse beam, the longitudinal beam and the bottom beam and is placed on the slope surface of the slope body to form a plurality of rectangular frames; b, leveling the slope surface, tightly filling the mortar and the stone in the concave part of the slope surface, and digging the placing groove of the protection slope structure; c, performing the anchor rod construction of the slope surface; d, placing the connecting prefabricated section; e, laying the cast-in-place section formwork at the connecting part; f, pouring the concrete; g, removing the formwork, prestressed anchor rod tensioning and anchor sealing; h, installing the vegetation system in the rectangular frame. The method combines the simple assembly connection beam prefabricated part and the node cast-in-place construction, guarantees the overall stability, reduces the cast-in-place process, and also improves the slope greening rate.

Description

Technical Field

[0001] This invention belongs to the technical field of slope engineering construction, specifically relating to a construction method for ecological slope protection of high slopes with loose and broken soil. Background Technology

[0002] Framed grid beam slope protection is widely used in slopes of highways, railways, and water diversion projects. Its main functions are to protect the slope surface, prevent soil loosening and erosion, enhance the overall integrity of the slope, and ensure its stability. Existing projects utilize various forms of framed grid beams for slope protection, with rectangular arrangements being the most common, typically cast-in-place reinforced concrete structures. The main construction process for cast-in-place reinforced concrete framed grid beam slope protection structures includes: excavation of the foundation trench, formwork support, reinforcement binding, concrete pouring, and concrete removal and curing. Framed grid beam slope protection is mostly used for stable soil slopes. However, when encountering high slopes with loose and fractured soil, using cast-in-place reinforced concrete framed grid beam structures presents challenges such as difficult support, low construction efficiency, and a high risk of incomplete compaction and formwork displacement during concrete pouring and vibration. Furthermore, planting vegetation on top of the cast-in-place grid beams is not possible, and the ecological benefits of the slope protection are poor. While using prefabricated frame beam revetments can improve construction efficiency, it results in poor overall stability after installation. Furthermore, the mesh reinforcement applied to the slope before spraying the substrate mixture restricts the movement of the ecological substrate. When there are significant slope elevation differences, it's difficult to ensure good adhesion between the mesh and the slope, leading to insufficient reinforcement of the ecological substrate and negatively impacting subsequent vegetation growth, resulting in poor ecological protection. Therefore, a construction method suitable for ecological slope protection of high slopes with loose and fractured soil is needed. Summary of the Invention

[0003] The purpose of this invention is to provide a construction method for ecological slope protection of high slopes with loose and broken soil. This construction method combines the construction of simple prefabricated connecting beams with the in-situ casting of joints, which ensures the overall stability while minimizing the in-situ casting process. Finally, a vegetation system is planted in the grid beam frame to improve the greening rate and durability of the slope.

[0004] This invention is achieved through the following technical solution:

[0005] A construction method for ecological slope protection of high slopes with loose and fractured soil includes the following construction steps:

[0006] a. Prefabricate the top beam prefabricated section, top beam prefabricated node section, bottom beam prefabricated section, bottom beam prefabricated node section, longitudinal beam prefabricated section and transverse beam prefabricated section according to the design drawings, and prepare the formwork for the cast-in-place section and the vegetation system; the slope protection structure is formed by combining and splicing the top beam, transverse beam, longitudinal beam and bottom beam and placing them on the slope surface to form multiple rectangular frames.

[0007] b. Level the slope surface, tightly fill the depressions with mortar-grouted rubble, and dig trenches for the placement of the slope protection structure; level the slope surface and depressions to ensure that there are no slippery, creeping, or loose rock blocks, and ensure that the grid beams are integrated and closely attached to the slope surface.

[0008] c. Construct anchor bolts on the slope according to the design drawings. The anchor bolt construction on the slope includes setting up drilling points along the anti-piling pile location line on the slope and starting drilling. After drilling is completed, anchor bolts can be installed and grouting can be performed. Grouting should be done in one go using the bottom-of-hole grouting method, and the grout must be full and dense. After grouting, grouting can be stopped when the expanded anchor section is formed and grout overflows from the borehole opening. After initial setting, grouting should be added to the borehole opening.

[0009] d. Place the precast sections of the top beam, top beam joints, bottom beam, bottom beam joints, longitudinal beams, and transverse beams at the corresponding positions in the trench, ensuring they are close to the slope; roughen the surfaces at their junctions to facilitate better connection during the in-situ casting of the junctions.

[0010] e. Lay the cast-in-place section formwork at the connection point; the angle of the cast-in-place section formwork needs to be considered, and it must be ensured that the axial direction of the prestressed anchor rod is perpendicular to the anchor plate and the anchor bracket. After assembling the node cast-in-place section formwork, it should be hoisted to the node position and laid uniformly; the outer contour dimension of the node cast-in-place section formwork should be larger than the outer dimension of the precast section structure to ensure that the dimensions of the cast-in-place node and the junction of the precast structure are consistent.

[0011] f. Pour concrete within the formwork of the cast-in-place section. Before pouring the joint concrete, the precast formwork of the joint must be fixed in place, and the quality of the reinforcement lap splices at the joint of the precast section must be checked.

[0012] g. After the strength meets the requirements, remove the formwork, tension the prestressed anchor rods, and seal the anchors. The formwork must be removed only after the concrete poured at the joint and the grouting body of the anchor rods have reached the design strength. The anchor cable tensioning is required to be no less than 25MPa. After grouting, stop grouting when the expanded anchoring section is formed and grout overflows from the borehole. After initial setting, grout is added to the borehole. The anchor rod ends are sealed with C30 concrete.

[0013] h. Install the vegetation system within the rectangular frame.

[0014] Further preferred configuration: The top beam is composed of precast top beam sections, precast top beam node sections, and cast-in-place top beam sections connected together. The precast top beam sections and precast top beam node sections are precast concrete components with embedded top beam lap reinforcement bars. The precast top beam sections are located on the sides of the precast top beam node sections and connected by the top beam lap reinforcement bars. A reserved space for the cast-in-place top beam section is provided between the precast top beam sections and the precast top beam node sections, and the cast-in-place top beam section is cast within this reserved space. The bottom beam is composed of precast bottom beam node sections, precast bottom beam sections, and cast-in-place bottom beam sections connected together. The precast bottom beam node sections and precast bottom beam sections are precast concrete components with embedded bottom beam lap reinforcement bars. The precast bottom beam sections are located on the sides of the precast bottom beam node sections and connected by the bottom beam lap reinforcement bars. A reserved space for the cast-in-place bottom beam section is provided between the precast bottom beam sections and the precast bottom beam node sections, and the cast-in-place bottom beam section is cast within this reserved space. The beam is precast in the reserved position for casting; the crossbeam includes multiple precast crossbeam segments, which are precast concrete components with embedded crossbeam lap reinforcement bars; the longitudinal beam includes multiple precast longitudinal beam segments, which are precast concrete components with embedded longitudinal beam lap reinforcement bars. The precast longitudinal beam segments are connected to the precast top beam segment, the precast bottom beam segment, and the precast crossbeam segments at corresponding positions through cast-in-place connection nodes. When the longitudinal beam is connected to the top beam and the bottom beam, the corresponding cast-in-place connection node segment is connected to the lower end of the corresponding precast top beam segment and the upper end of the corresponding precast bottom beam segment. The cast-in-place connection node segment is provided with node connecting reinforcement bars, and the node connecting reinforcement bars in the cast-in-place connection node segment at the corresponding position are welded to the corresponding longitudinal beam lap reinforcement bars, crossbeam lap reinforcement bars, top beam lap reinforcement bars, and bottom beam lap reinforcement bars; the cast-in-place connection node segment is provided with anchor rods anchored into the slope body, and the exposed ends of the anchor rods are sealed with anchors. Anchor bolts are treated for rust removal, corrosion prevention, and rust protection according to permanent use requirements. Free sections should be coated with corrosion-resistant grease before being fitted with heat-shrink tubing, sealed at both ends, and secured with engineering tape. Tensioning and anchoring sections are protected with an external anti-corrosion coating. Slope anchor foundation construction includes drilling at the anti-pile location line on the slope, followed by anchor placement and grouting. Grouting uses a bottom-return grouting method, ensuring the grout is full and dense. Grouting can be stopped when the expanded anchoring section is formed and grout overflows from the borehole opening. After initial setting, additional grout is applied to the borehole opening. The cast-in-place section of the connection node is formed by pouring concrete through a formwork after the connection reinforcement bars are connected. The exposed ends of the anchor bolts are sealed by pouring concrete through a sealing formwork after tensioning. The top beam, bottom beam, and connection node sections are all cast-in-place using C30 concrete.

[0015] A further preferred embodiment: The vegetation system includes a reinforcing net, ecological bags, and reinforced Mac mats. The reinforcing net is fixed to the slope within a rectangular frame by anchor plates and anchors. The ecological bags are stacked on the reinforcing net, and the reinforced Mac mats are laid on top of the ecological bags. The reinforced Mac mats are connected to the reinforcing net by connecting buckles.

[0016] This construction method for ecological slope protection of high slopes in loose and fractured soil combines simple precast connecting beams with cast-in-place joint construction. This ensures overall stability while minimizing cast-in-place steps, accelerating construction speed, saving manpower and resources, and guaranteeing construction quality. It offers better overall integrity than precast assembly, with stable joint structures, making it suitable for ecological slope protection of high slopes in loose and fractured soil. It reduces slope collapse and movement caused by geological and topographical factors. It also overcomes the difficulties and low construction efficiency of cast-in-place reinforced concrete structures, and the high risk of incomplete compaction and formwork displacement during concrete pouring and vibration, inherent in fully cast-in-place construction of high slopes in loose and fractured soil. Furthermore, it overcomes the problems of weak joint structures and poor ground stability in precast frame beam protection structures. Finally, this construction method for ecological slope protection of high slopes in loose and fractured soil involves planting a vegetation system within the grid beam frame to improve the slope's greening rate and vegetation durability. Designing a fixed vegetation system can prevent birds and animals from damaging seeds and causing soil erosion, thereby increasing the greening rate and durability of the slope and effectively extending the service life of the slope, while reducing the cost and workload of daily maintenance and repair. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the slope protection structure layout on the slope surface;

[0018] Figure 2 This is a schematic diagram of the slope protection structure without a vegetation system.

[0019] Figure 3 This is a schematic diagram of the pouring arrangement at the connection node between the horizontal beam and the longitudinal beam;

[0020] Figure 4 This is a schematic diagram of the connection structure of the precast top beam section;

[0021] Figure 5 This is a schematic diagram of the connection structure of the precast bottom beam section;

[0022] Figure 6 This is a schematic diagram of the connection structure of the vegetation system;

[0023] The names corresponding to the serial numbers in the figure are:

[0024] 1. Slope; 2. Slope surface; 3. Precast top beam section; 4. Cast-in-place reserved space for top beam; 5. Vegetation system; 6. Cast-in-place section for connection nodes; 7. Precast bottom beam section; 8. Cast-in-place reserved space for bottom beam; 9. Precast bottom beam section; 10. Horizontal beam; 11. Longitudinal beam; 12. Precast top beam section; 13. Reinforcing mesh; 14. Node connecting bars; 15. Formwork for cast-in-place node section; 16. Anchor sealing formwork; 17. Longitudinal beam lap joint bars; 18. Anchor rod; 19. Horizontal beam lap joint bars; 20. Precast longitudinal beam section; 21. Top beam lap joint bars; 22. Bottom beam lap joint bars; 23. Connecting buckle; 24. Ecological bag; 25. Reinforced micromat; 26. Anchor pad; 27. Anchor nail; 28. Precast horizontal beam section. Detailed Implementation

[0025] To provide a clearer description of this technology, the following detailed explanation is provided in conjunction with the accompanying drawings and embodiments.

[0026] Example 1

[0027] The following construction steps can be used to complete the construction of ecological slope protection for high slopes with loose and broken soil:

[0028] a. Prefabricate the top beam prefabricated section, top beam prefabricated node section, bottom beam prefabricated section, bottom beam prefabricated node section, longitudinal beam prefabricated section and transverse beam prefabricated section according to the design drawings, and prepare the formwork for the cast-in-place section and the vegetation system; the slope protection structure is formed by combining and splicing the top beam, transverse beam, longitudinal beam and bottom beam and placing them on the slope surface to form multiple rectangular frames.

[0029] b. Level the slope surface, tightly fill the depressions with mortar-grouted rubble, and dig trenches for the placement of the slope protection structure; level the slope surface and depressions to ensure that there are no slippery, creeping, or loose rock blocks, and ensure that the grid beams are integrated and closely attached to the slope surface.

[0030] c. Construct anchor bolts on the slope according to the design drawings. The anchor bolt construction on the slope includes drilling from the designated drilling points along the anti-piling line. Once drilling is complete, anchors can be installed and grouting can begin. Grouting should be done in one pass using the bottom-of-hole grouting method, ensuring the grout is full and dense. After grouting, stop when the expanded anchor section is formed and grout overflows from the borehole opening. After initial setting, replenish the grout at the borehole opening. The prestressed anchor bolt body should be treated for rust removal, corrosion prevention, and rust protection according to permanent use requirements. The free section should be coated with corrosion-resistant grease, then a heat-shrink sleeve should be inserted, both ends sealed, and externally secured with engineering tape. The tensioning and anchoring sections should be protected with an external anti-corrosion coating.

[0031] d. Place the precast sections of the top beam, top beam nodes, bottom beam, bottom beam nodes, longitudinal beams, and transverse beams at the corresponding positions in the placement trench. Reserve lapped steel bars at the junctions of the grid beam nodes. Place the precast assembled structures into the placement trench on the slope in sequence using a crawler crane, ensuring they are close to the slope. Roughen the surfaces at their junctions to facilitate better connection during the in-situ casting at the junctions.

[0032] e. Lay the cast-in-place section formwork at the connection point; the angle of the cast-in-place section formwork needs to be considered, and it must be ensured that the axial direction of the prestressed anchor rod is perpendicular to the anchor plate and the anchor bracket. After assembling the node cast-in-place section formwork, it should be hoisted to the node position and laid uniformly; the outer contour dimension of the node cast-in-place section formwork should be larger than the outer dimension of the precast section structure to ensure that the dimensions of the cast-in-place node and the junction of the precast structure are consistent.

[0033] f. Pour concrete within the formwork of the cast-in-place section. Before pouring the joint concrete, the precast formwork of the joint must be fixed in place, and the quality of the reinforcement lap splices at the joint of the precast section must be checked.

[0034] g. After the strength meets the requirements, remove the formwork, tension the prestressed anchor rods, and seal the anchors. The formwork must be removed only after the concrete poured at the joint and the grouting body of the anchor rods have reached the design strength. The anchor cable tensioning is required to be no less than 25MPa. After grouting, stop grouting when the expanded anchoring section is formed and grout overflows from the borehole. After initial setting, grout is added to the borehole. The anchor rod ends are sealed with C30 concrete.

[0035] h. Install the vegetation system within the rectangular frame.

[0036] The aforementioned top beam is composed of a precast top beam section 3, a precast top beam node section 12, and a cast-in-place top beam section. The precast top beam section 3 and the precast top beam node section 12 are precast concrete components with embedded top beam lap reinforcement bars 21. The precast top beam section 3 is located on the side of the precast top beam node section 12 and is connected by the top beam lap reinforcement bars 21. A reserved space 4 for the cast-in-place top beam section 4 is provided between the precast top beam section 3 and the precast top beam node section 12 for the cast-in-place top beam section. The cast-in-place top beam section is cast within the reserved space 4. The bottom beam is composed of a precast node segment 7, a precast section 9, and a cast-in-place section. The precast node segment 7 and the precast section 9 are precast concrete components with embedded bottom beam lap reinforcement bars 22. The precast section 9 is located on the side of the precast node segment 7 and connected by the lap reinforcement bars 22. A reserved space 8 for the cast-in-place bottom beam section 8 is provided between the precast section 9 and the precast node segment 7. The cast-in-place bottom beam section is cast within this reserved space 8. The crossbeam 10 comprises multiple precast crossbeam segments 28, each precast concrete component with embedded crossbeam lap reinforcement bars 19. The longitudinal beam 11 comprises multiple precast longitudinal beam segments 20, each precast concrete component with embedded longitudinal beam lap reinforcement bars 17. The longitudinal beam segments 20 are connected to the top beam precast node segment 12, the bottom beam precast node segment 7, and the crossbeam segments 28 at corresponding positions via the cast-in-place connection node segment 6. When the longitudinal beam 11 is connected to the top beam and the bottom beam... The corresponding cast-in-place section 6 of the connecting node is connected to the lower end of the corresponding precast top beam section 12 and the upper end of the precast bottom beam section 7. Connecting reinforcement bars 14 are installed within the cast-in-place section 6 of the connecting node. These connecting reinforcement bars 14 are connected to the corresponding longitudinal beam lap reinforcement bars 17, transverse beam lap reinforcement bars 19, top beam lap reinforcement bars 21, and bottom beam lap reinforcement bars 22. Anchor rods 18 are inserted into the slope 1 within the cast-in-place section 6 of the connecting node, and the exposed ends of the anchor rods 18 are sealed with concrete. The cast-in-place section 6 of the connecting node is formed by pouring concrete through the formwork 15 after the connecting reinforcement bars 14 are connected. The sealed ends of the anchor rods 18 are formed by pouring concrete through the sealing formwork 16 after the tensioning process is completed.

[0037] The vegetation system 5 includes a reinforcing net 13, ecological bags 24, and a reinforcing Mac mat 25. The reinforcing net 13 is fixed to the slope 2 within the rectangular frame by anchor plates 26 and anchors 27. The ecological bags 24 are stacked on the reinforcing net 13, and the reinforcing Mac mat 25 is laid on the ecological bags 24. The reinforcing Mac mat 25 is connected to the reinforcing net 13 by connecting buckles 23. After the vegetation system is installed, routine maintenance is required.

[0038] The above description is not intended to limit this application, nor is this application limited to the examples described above. Any changes, modifications, additions, or substitutions made by those skilled in the art within the scope of this application should fall within the protection scope of this application.

Claims

1. A construction method for ecological slope protection of high slopes with loose and fractured soil, characterized in that: The construction steps include the following: a. Preparing the top beam precast section, top beam precast node section, bottom beam precast section, bottom beam precast node section, longitudinal beam precast section and transverse beam precast section of the slope protection structure according to the design drawing, preparing the cast-in-place section formwork and the vegetation system; the slope protection structure is composed of top beams, transverse beams, longitudinal beams and bottom beams, which are combined and jointed to form a plurality of rectangular frames on the slope surface of the slope body; b. Smoothing the slope surface, tightly filling the mortar and stone in the concave part of the slope surface, and digging the placing trench of the slope protection structure; smoothing the slope surface and the concave part of the slope surface to ensure that there are no sliding bodies, creeping bodies and loose rock blocks, and to ensure that the frame beams are integrated and closely attached to the slope surface; c. Carrying out the anchor rod construction of the slope surface according to the design drawing; d. Placing the connecting top beam precast section, top beam precast node section, bottom beam precast section, bottom beam precast node section, longitudinal beam precast section and transverse beam precast section in the corresponding position of the placing trench; e. Laying the cast-in-place section formwork at the connecting part; f. Pouring concrete in the cast-in-place section formwork; g. After the strength reaches the requirement, removing the formwork, pre-stressed anchor rod tensioning and anchor sealing; h. Installing the vegetation system in the rectangular frame. The roof beam is connected by a roof beam prefabricated section (3), a roof beam prefabricated node section (12) and a roof beam cast-in-place section, the roof beam prefabricated section (3) is located at the side of the roof beam prefabricated node section (12) and is connected by a roof beam lap joint (21), a roof beam prefabricated section (3) and a roof beam prefabricated node section (12) are left with a roof beam cast-in-place reserved position (4) for casting the roof beam cast-in-place section; the bottom beam is connected by a bottom beam prefabricated node section (7), a bottom beam prefabricated section (9) and a bottom beam cast-in-place section, the bottom beam prefabricated section (9) is located at the side of the bottom beam prefabricated node section (7) and is connected by a bottom beam lap joint (22), the bottom beam prefabricated section (9) and the bottom beam prefabricated node section (7) are left with a bottom beam cast-in-place reserved position (8) for casting the bottom beam cast-in-place section; the cross beam (10) comprises a plurality of cross beam prefabricated sections (28), the longitudinal beam (11) comprises a plurality of longitudinal beam prefabricated sections (20), the longitudinal beam prefabricated section (20) is connected with the roof beam prefabricated node section (12), the bottom beam prefabricated node section (7) and the cross beam prefabricated section (28) at the corresponding position through a connecting node cast-in-place section (6), the connecting node cast-in-place section (6) is provided with a node connecting rib (14), the connecting node cast-in-place section (6) is provided with an anchor rod (18) anchored into the slope (1), the exposed end of the anchor rod (18) is poured with an anchor seal, the anchor seal is obtained by pouring concrete through an anchor seal formwork after the tensioning work is completed, the connecting node cast-in-place section (6) is formed by pouring concrete through a node cast-in-place section formwork (15) after the node connecting rib (14) is connected; the node cast-in-place section formwork (15) must ensure that the prestressed anchor rod axis is perpendicular to the anchor pad and the anchor inclined support, the node cast-in-place section formwork (15) is hoisted to the node position after being assembled and is uniformly laid; the vegetation system (5) comprises a reinforced mesh (13), an ecological bag (24) and a reinforced Mac pad (25), the reinforced mesh (13) is fixed on the slope surface (2) in the rectangular frame through an anchor nail pad (26) and an anchor nail (27), the ecological bag (24) is piled on the reinforced mesh (13), the reinforced Mac pad (25) is laid on the ecological bag (24), and the reinforced Mac pad (25) is connected with the reinforced mesh (13) through a connecting buckle (23).

2. The construction method of the ecological protection and revetment of the high loose broken soil slope according to claim 1, characterized in that: The anchor rod construction of the slope surface comprises placing a pile position line on the slope surface, arranging a drilling point to start drilling construction, anchoring after drilling is completed, grouting, grouting adopts hole bottom back grouting method, and the slurry must be full and dense; after grouting, stop grouting when the expansion body anchoring section is formed and overflow appears at the hole mouth, and hole mouth supplementary grouting is carried out after initial setting.

3. The construction method of the ecological protection and revetment of the high loose broken soil slope according to claim 1, characterized in that: In step g, the formwork must be removed after the node poured concrete and the anchor rod grouting body reach the design strength, the concrete strength is required to be not less than 25MPa; after grouting, stop grouting when the expansion body anchoring section is formed and overflow appears at the hole mouth, hole mouth supplementary grouting is carried out after initial setting, and the anchor rod end is sealed by C30 concrete.

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