A pull-up anchoring structure and construction method based on tree root-like anchors and anti-buoyancy tension.

Abstract

This invention discloses a cable-stayed anchorage structure and construction method based on tree root-like anchors and anti-buoyancy tension, belonging to the field of large-tonnage anchorage technology in geotechnical engineering. The structure includes core components such as artificial anchors, tree root-like anchor cables, upper tension anchors, anti-buoyancy anchor cables / rods, transverse anchor beams, retaining piles, and ground piles. Through core technologies such as three-dimensional radial anchoring, asymmetric outer thickness, three-level force transmission, an anti-buoyancy and anti-slip combined system, end-expansion structure to enhance load-bearing capacity, a date-shaped diameter expansion structure, and node force connection, it achieves efficient transmission of anchoring force and stable load-bearing capacity. The artificial anchors adopt a tree root-like structure, significantly reducing concrete usage; the upper tension anchors, anti-buoyancy anchor cables / rods, and bearing anchors work together to achieve pull-out and anti-slip resistance; the ground piles and connecting anchor plates ensure tension balance and continuous force distribution. This invention improves anchoring efficiency by 2 to 3 times, reduces concrete usage by 70% to 90%, reduces project costs by 69% to 83%, and achieves a safety factor of 2.0 to 2.5. It is applicable to various engineering scenarios such as slope protection, bridge anchorage, deep foundation pit support, landslide control, and anti-buoyancy of underground engineering. It can be widely adapted to complex geological conditions such as rock, soil, soft soil, and fractured rock layers, and combines safety, economy, and environmental friendliness.

Description

Technical Field

[0001] This invention belongs to the field of geotechnical engineering technology and relates to a cable-stayed anchorage structure. Specifically, it relates to an up-pull anchorage structure and construction method based on tree root-like anchorage and anti-buoyancy tension. It is applicable to large-tonnage anchorage projects such as slope protection, suspension / cable-stayed bridge anchorage, deep foundation pit support, landslide control, and anti-buoyancy of underground engineering. It can be widely adapted to complex geological conditions such as rock foundation, soil foundation, soft soil foundation, and fractured rock strata. Background Technology

[0002] Prestressed anchor cable frames and anti-slide piles are widely used in slope protection, foundation pit support, and landslide control projects, but existing anchoring technologies have three major drawbacks:

[0003] (1) Traditional artificial prestressed anchorages rely on a large amount of concrete fill to provide anchorage force. The amount of concrete used increases geometrically with the increase of the anchorage area, resulting in a significant increase in material and construction costs and serious waste of resources.

[0004] (2) The construction of super anchor cable end expansion structure has extremely high requirements for large special equipment and high air volume air compressor. The large diameter expansion technology of ≥600mm is not yet fully mature. The construction is difficult and the cost is much higher than that of ordinary drilling operations, resulting in poor economic efficiency.

[0005] (3) The lower end of the super anchor beam, which is used to provide upward anchoring, lacks sufficiently large and reliable anchoring support, making it difficult to meet the long-term stress and safety and stability requirements under large tonnage loads, and there are safety hazards such as floating and slippage.

[0006] Existing technologies are insufficient to balance the safety, economy, and efficiency of engineering projects. Therefore, there is an urgent need for a new type of anchoring structure and construction method to break through the bottlenecks of traditional technologies. Summary of the Invention

[0007] I. Structural Composition

[0008] The inclined anchoring structure of the present invention is composed of multiple components working together to form a complete anchoring system. The core components include: vertical anchor beam (1), anchoring anchor beam (2), upper pull anchor (3), anchor bearing anchor rod (4), anti-buoyancy anchor cable / anchor rod (5), anchoring anchor beam and vertical anchor beam connector (7), ground pile (9), artificial anchor (10), tree root-shaped anchor cable (11), anchor cable wrapped with concrete or mortar material (12), upper pull anchor body anchor cable (13), horizontal anchor beam (14), super anchor cable (15), retaining pile (16), pile top anchor plate (17), pile top anchor plate anchor hole (18), forward anchor hole (19), reverse anchor hole (20), butt anchor plate (21), ground pile body (22), pile top anchor plate bearing anchor rod (23), pile top anchor plate anchor pad steel plate (24).

[0009] II. Core Structural Features

[0010] (1) Artificial anchorage and root-like anchor cable system

[0011] Artificial anchorages (10) serve as the core anchoring components, located at both ends of the suspension anchor beam or the anti-tension end of the inclined anchor beam. Their side branches are arranged in a spatially radial pattern with 3 to 12 bundles of root-like anchor cables (11), and the center is equipped with a middle branch anchor cable extending along the main cable direction, together forming a three-dimensional anchoring system that can fully mobilize the three-dimensional bearing capacity of the stratum. Some branches of the root-like anchor cables (11) protrude into the mountain to form a convex side, while the other side is a concave side. The concrete or mortar material (12) encasing the anchor cables adopts a differentiated thickness design (t2≥2t1 and t2 / t1=2~40), which ensures both a balanced stress distribution and precise material configuration, significantly reducing the amount of concrete used. This design follows the principle of "increasing soil usage without reducing anchoring force," and breaks through the traditional design logic of anchorages relying on the self-weight of concrete by fully utilizing the compressive strength of the soil.

[0012] The ends of the artificial anchor (10) root-like branches, the deep ends of the anti-buoyancy anchor cable / anchor (5), the deep ends of the anchor bearing anchor (4), and the deep ends of the pile top anchor plate bearing anchor (23) are all equipped with end expansion structures. The expansion diameter is 400-2000mm and the expansion section length is 1.0-2.0m, which effectively increases the end bearing capacity.

[0013] (2) Upper anchor and anti-buoyancy and anti-slip components

[0014] The upper anchorage (3) is a key load-bearing component, with a height controlled between 0.3 and 5 m and a thickness between 0.3 and 1.5 m, to meet the needs of different project scales. Its upper part is connected to the anchor beam (2) through the anchorage, and the anchor beam (2) is then fixed to the vertical anchor beam (1) through the anchor beam and vertical anchor beam connector (7), forming a longitudinal force transmission path; the lower end is connected to the anti-buoyancy anchor cable / anchor rod (5) anchored in the deep stable stratum, effectively suppressing the upward movement of the upper anchorage (3); the extension section of the anti-buoyancy anchor cable / anchor rod (5) forms the anchor cable (13) inside the upper anchorage, and is eccentrically anchored to the top of the upper anchorage (3) on the mountain side, working together with the inclined anchorage bearing anchor rod (4) set on the top mountain side to achieve the dual functions of pull-out resistance and anti-slip resistance, greatly reducing the pull-out resistance anchor cable / anchor rod (5) tension requirement. The angle between the anti-buoyancy anchor cable / anchor rod (5) and the vertical direction is controlled within -10°≤α≤45°, which can be flexibly adjusted according to geological conditions to optimize the stress state.

[0015] (3) Transverse anchor beam and retaining pile system

[0016] The transverse anchor beam (14) is fixed at the corresponding position of the anchor beam (2) and is connected to the upper anchor (3) through steel structure and anchorage to achieve lateral force coordination. One or more retaining piles (16) are set on the mountain side of the transverse anchor beam (14). The retaining piles (16) can be circular or polygonal. The anchor bearing anchor rods (4) are arranged on the mountain side, and the lower part is set with anti-buoyancy anchor cables / anchor rods (5), which together form an anti-buoyancy and anti-slip reinforcement system. This system can effectively prevent the transverse anchor beam (14) from floating under force, further expand the anti-slip limit value of the anchor beam (2), and improve the stability of the overall structure.

[0017] (4) Ground piles and anchorage nodes

[0018] The ground pile (9) is integrally cast with reinforced concrete by the pile top anchor plate (17) and the ground pile body (22), and the structure has strong integrity. The pile top anchor plate (17) has a plane dimension of 100-450cm×100-450cm perpendicular to the tunnel length direction and a thickness of 50-300cm. Curved pile top anchor plate anchor holes (18) are opened on it, with a turning angle range of 30°-90°. The linear section uses stainless steel corrugated pipe or steel pipe to ensure that the prestressed steel strands achieve a smooth turning angle and avoid stress concentration. Pile top anchor plate anchor pad steel plates (24) are set on both sides of the plane of the pile top anchor plate (17). During tensioning, anchors can be set on the steel plates on both sides for forward or reverse anchoring to realize the tensioning and locking of the steel strands led out from the artificial anchor (10). A connecting anchor plate (21) is installed on the side of the ground pile (9) near the open face of the mountain. The connecting anchor plate (21) is respectively arranged with forward anchor holes (19) and reverse anchor holes (20). For the position where the steel strand is not continuous, the steel strand is locked by inserting a clamp to complete the force connection and ensure the continuity of force. The side of the pile top anchor plate (17) near the mountain is filled with reinforced concrete, which, together with the pile top anchor plate bearing anchor rod (23), forms a counter-pressure structure to achieve the balance between tension and reaction force, and ensure that the foundation on the side of the pile top anchor plate (17) and the pile top anchor plate bearing anchor rod (23) are within the design allowable range under the unbalanced pressure generated by the tension of the steel strand.

[0019] (5) Super Anchor Cable Optional Structure

[0020] For anchorage requirements of ultra-large tonnage, the cable-stayed anchor beam can adopt artificial anchorage (10), super anchor cable (15), or a combination of both. The super anchor cable (15) has an enlarged diameter structure at the end, with an enlarged diameter of 600-1200mm and an enlarged section length of 1.0-2.0m. The bearing capacity of a single super anchor cable can reach 2000-10000kN, which can meet the needs of ultra-large tonnage anchorage scenarios such as anchorage of long-span bridges.

[0021] III. Working Principle

[0022] The anchoring system of this invention achieves efficient and stable anchoring of large tonnage vessels through the synergistic action of multiple components. The core working principle is as follows:

[0023] (1) Three-dimensional anchoring and material optimization: The artificial anchor (10) forms a three-dimensional anchoring system through the root-like radial distribution of anchor cables and the central branch anchor cable, which fully mobilizes the three-dimensional bearing capacity of the stratum; following the principle of "increasing the amount of soil without reducing the anchoring force", by giving full play to the compressive strength of the soil, the amount of concrete or mortar material (12) wrapped around the anchor cable is greatly reduced, thus reducing the engineering cost.

[0024] (2) Synergistic effect of anti-buoyancy and anti-slip: The anti-buoyancy anchor cable / anchor rod (5) in the lower part of the upper anchor (3) effectively suppresses the floating problem caused by the upper pull of the anchor beam (2), and the pressure-bearing anchor rod (4) at the top further enhances the anti-slip force. The two work together to optimize the stress state; the anti-buoyancy and anti-slip reinforcement system composed of the transverse anchor beam (14), the retaining pile (16), the anchor rod, and the anchor cable further expands the anti-slip force limit value of the anchor beam (2) and ensures the stability of the structure under complex stress.

[0025] (3) End expansion structure to enhance bearing capacity: The artificial anchor (10) root-like branch ends and the deep ends of each anchor rod / anchor cable are equipped with end expansion structures. Through the interlocking effect of the expansion section with the surrounding rock and soil, the end bearing capacity is significantly improved, ensuring the long-term stability of the anchoring system under large tonnage loads.

[0026] (4) Tension balance mechanism: The anchor plate (17) at the top of the ground pile (9) can complete the tensioning and locking of the steel strands led out from the artificial anchor (10). The anchor plate at the top of the pile bears the anchor rod (23) and forms a counter-pressure structure with the ground pile body (22) to achieve the balance between tension and reaction force. During the tensioning process, the load difference on both sides of the anchor plate (17) at the top of the pile is controlled within the design allowable range to ensure the system is stress-balanced.

[0027] (5) Stress optimization and force connection: The three-level anchoring design of the root-shaped anchor cable (11), combined with the asymmetric outer thickness, allows the anchoring force to be transmitted along the length gradient of the anchor cable, avoiding local stress concentration; the curved pile top anchor plate anchor hole (18) ensures the smooth rotation angle of the steel strand, and the butt anchor plate (21) realizes the force connection at the break of the steel strand, improving the overall structure and durability.

[0028] IV. Construction Method

[0029] The construction method of this invention follows the principles of "precise positioning, graded construction, coordinated anchoring, and safe and controllable operation," and is divided into two parts: the construction of the anti-sliding end and the construction of the anti-sliding structure within the landslide body. The specific steps are as follows:

[0030] I. Construction of the reverse pull end (outer middle and upper part of the landslide area)

[0031] (1) Tunnel excavation and support: Excavate the tunnel according to the design plan. The tunnel size must meet the requirements for personnel, equipment passage and steel strand placement space. At the same time, dust prevention and ventilation facilities should be arranged to ensure construction safety and environmental compliance.

[0032] (2) Construction of the ground pile: Excavate the foundation pit of the ground pile (9), tie the steel bars according to the design, pour the concrete of the ground pile body (22), and cure it to the design strength;

[0033] (3) Excavation of artificial anchor bifurcation holes: Excavate the artificial anchor (10) holes in different directions to form tree root bifurcations, leaving enough space and area for the steel strand arrangement, and at the same time do a good job of hole wall support (such as shotcrete support) to prevent collapse;

[0034] (4) Construction of pile top anchor plate: Tie the pile top anchor plate (17) steel bars, install the pile top anchor plate anchor pad steel plate (24), ensure the anchor hole position is accurate, and pour concrete to form the shape;

[0035] (5) Steel strand bundle layout: Install and lay out steel strand bundles, strictly distinguish between anchored sections and free sections, increase the friction of steel strands in anchored sections and reduce the friction of steel strands in free sections to reduce the frictional load between them and the surrounding rock walls.

[0036] (6) Concrete pouring and anchor construction: pour artificial anchor (10) and tunnel concrete to ensure that the pouring is dense; simultaneously construct the bearing anchor (23) of the pile top anchor plate (17), drill holes, lower the anchor and then grout for anchoring, and set the end expansion structure at the deep end of the anchor.

[0037] (7) Filling: Fill the gap between the anchor plate (17) at the top of the pile and the side facing the mountain with high-strength mortar or concrete to ensure close contact and uniform stress.

[0038] (8) Tensioning and locking in batches: After the concrete strength meets the design requirements, the subsequent prestressing tensioning and anchoring are carried out in batches. By tensioning in batches, the uneven load on both sides of the pile top anchor plate (17) is controlled within the range specified in the design, so as to avoid structural stress imbalance.

[0039] II. Construction of Anti-sliding Structures within the Landslide Body

[0040] (1) Construction of anti-buoyancy anchor cable / anchor rod: Drill anti-buoyancy anchor cable / anchor rod (5) ducts according to the design position to ensure that the verticality and depth of the ducts meet the requirements; after lowering the anchor cable body or anchor rod, carry out grouting operation. High-strength cement mortar is selected as the grouting material. Control the grouting pressure and speed to ensure that the grouting is dense; strictly control the grouting height so that the 1.0 to 2.0m range above the bottom of the upper anchor (3) pit is not grouted, forming a free section to ensure the post-tensioning effect; set the end expansion structure at the deep end of the anchor cable / anchor rod;

[0041] (2) Foundation excavation and anchor construction: The upper anchor (3) foundation pit is excavated by layer excavation to avoid the collapse of the foundation pit; the groove of the transverse anchor beam (14) and the foundation of the retaining pile (16) are excavated at the same time; the anchor bearing anchor (4) duct is constructed by mechanical drilling combined with manual trimming, and the anchor is grouted after being lowered. The deep end of the anchor is equipped with an end expansion structure.

[0042] (3) Waterproofing, corrosion protection and installation of embedded parts: Tie the foundation steel bars of the upper anchor (3), accurately fix the position of the anti-buoyancy anchor cable / anchor rod (5), and do waterproofing and corrosion protection treatment at the connection between the anti-buoyancy anchor cable / anchor rod (5) and the bottom of the upper anchor (3) (such as applying anti-corrosion coating and setting a waterproof pad); install the embedded parts and anchors of the anchor beam (2) to ensure installation accuracy;

[0043] (4) Concrete pouring and curing: Pour reinforced concrete for the upper anchor (3) and retaining pile (16), using C30 to C50 high-strength concrete, and vibrate to compact it; the curing time shall not be less than 7 days to ensure that the concrete strength meets the design requirements;

[0044] (5) Tensioning and locking: Install the anchor beam and vertical anchor beam connector (7), use a jack that matches the anchor cable specification to tension the anchor beam (2) and lock it to ensure stable transmission of anchoring force;

[0045] (6) Anti-corrosion protection treatment: After all the lower end structures of the vertical anchor beam (1) are connected and tensioned, spiral stirrups (stirrup spacing 100-150mm) are laid on the anchor beam (2) and the vertical anchor beam (1), anti-corrosion mortar is injected and vibrated to form a closed protective layer to prevent steel components from rusting and extend the service life of the structure.

[0046] V. Beneficial Effects

[0047] Through core technological innovation and structural optimization, this invention offers the following significant advantages over existing technologies:

[0048] (1) Significantly optimized economic efficiency: The root-like anchor design greatly reduces the amount of concrete used (70% to 90%). Combined with the simplified construction process, the project cost is reduced by 69% to 83% compared with traditional technology, the construction period is shortened by 50% to 70%, significantly reducing project cost and time cost, and greatly improving resource utilization.

[0049] (2) The anchoring efficiency is greatly improved: the three-dimensional anchoring system and the three-level graded force transmission design improve the anchoring efficiency by 2 to 3 times, and the material utilization rate of a single anchor cable is ≥80%, which can meet the anchoring requirements of large tonnage (the bearing capacity of a single anchor cable can reach 20,000 to 300,000 kN) and is suitable for projects of different scales.

[0050] (3) Strong geological adaptability: The three-dimensional decentralized anchoring method can fully mobilize the bearing capacity of different strata, adapt to complex geological conditions such as soft soil, fractured rock, and sand and gravel layers, solve the strict limitations of traditional technology on geological conditions, and has a wide range of applications;

[0051] (4) High safety and stability: The anti-buoyancy and anti-slip combined system and the end expansion structure enhance the load-bearing and tension balance mechanism, so that the overall safety factor reaches 2.0 to 2.5, the structural displacement is controllable, effectively avoids safety hazards such as floating and sliding, and ensures the long-term stable operation of the project;

[0052] (5) Simple and controllable construction: Reduces dependence on large-diameter expansion equipment and high-power air compressors. The process is mature and easy to implement. The graded construction and tensioning process can effectively control the construction quality and reduce construction risks.

[0053] (6) Green and environmentally friendly: The reduction in concrete usage and the shortening of the construction period significantly reduce carbon emissions and energy consumption, meeting the requirements of green building and sustainable development, and reducing the impact on the surrounding environment. Attached Figure Description

[0054] Figure 1 Overall schematic diagram of anchorage structure Figure 1 (The core components are labeled: 1-vertical anchor beam, 2-anchoring anchor beam, 3-uplift anchor, 9-ground pile, 10-manual anchor, 14-horizontal anchor beam, 16-stop pile, showing the spatial connection relationship of each component).

[0055] Figure 2 Overall schematic diagram of anchorage structure Figure 2 (The core components are labeled: 1-vertical anchor beam, 2-anchoring anchor beam, 3-uplift anchor, 9-ground pile, 10-manual anchor, 14-horizontal anchor beam, 16-retaining pile, and super anchor cable 15, showing the spatial connection relationship of each component.)

[0056] Figure 3 Schematic diagram of root-like anchorage and anti-buoyancy structure (label: 10-artificial anchorage, 11-root-like anchorage cable, 12-anchorage cable encased in concrete or mortar material, showing three-dimensional radial distribution and the location of the middle branch anchorage).

[0057] Figure 4 Schematic diagram of the arrangement of root-shaped anchors and anti-slide piles (labels: 10-artificial anchor, 11-root-shaped anchor cable, 12-anchor cable wrapped with concrete or mortar material, super anchor 15, anti-slide pile 6, showing the three-dimensional radial distribution and the position of the middle branch anchor).

[0058] Figure 5 Schematic diagram of the anti-buoyancy and anti-slip system of the upper anchor (labeled: 3-upper anchor, 4-anchor bearing anchor rod, 5-anti-buoyancy anchor cable / anchor rod, 13-anchor cable inside the upper anchor, showing the cooperative force relationship);

[0059] Figure 6 Schematic diagram of the upper anchorage anti-buoyancy and anti-slip system (labeled: 3-upper anchorage, 5-anti-buoyancy anchor cable / anchor rod, 13-anchor cable inside the upper anchorage, showing the cooperative force relationship);

[0060] Figure 7 Construction diagram of the ground-mounted pile and pile top anchor plate (labeled: 9-ground-mounted pile, 17-pile top anchor plate, 18-pile top anchor plate anchor hole, 21-butt anchor plate, 22-ground-mounted pile body, 23-pile top anchor plate bearing anchor rod, 24-pile top anchor plate anchor pad steel plate, showing the node structure).

[0061] Figure 8 Schematic diagram of the force on the anchor plate (label: 21-anchor plate, 19-forward anchor hole, 20-reverse anchor hole, showing the locking method of the steel strand connection). Detailed Implementation

[0062] The following three practical engineering cases further illustrate the application effects of this invention. All cases strictly follow the structural design and construction methods of this invention:

[0063] Example 1: Highway Slope Protection Engineering

[0064] A highway slope protection project has a slope height of 35m, a slope of 1:0.75, a design anchoring force of 80000kN, and a geological layer consisting of silty clay and strongly weathered rock. The technical solution of this invention is adopted: the root-shaped anchor cable (11) is made of 50 bundles of Φ15.2mm steel strands, with spatial distribution angles of 35°, 50°, 65°, and 80°, and the horizontal azimuth angle of adjacent branches is 45°; the outer thickness of the protruding side is t1=80mm, and the concave side is t2=1800mm (t2 / t1=22.5); the anti-buoyancy anchor cable / anchor rod (5) has an angle α=25° with the vertical direction; the retaining pile (16) is a Φ600mm circular pile; the artificial anchor root-shaped branch end is equipped with an end expansion structure with an expansion diameter of 600mm and an expansion section length of 1.2m. After construction, the concrete usage was only 18m³ (compared to over 60m³ for traditional technology), the construction period was 12 days (compared to 30 days for traditional technology), the slope displacement was controlled within 8mm, the cost was reduced by 73%, the safety factor reached 2.15, meeting the design requirements, and no significant deformation was observed after 2 years of monitoring.

[0065] Example 2: Anchorage Engineering for Long-Span Suspension Bridges

[0066] The anchorage project for a long-span suspension bridge has a span of 1200m and a designed anchorage force of 120000kN. The geological conditions are moderately weathered granite. A hybrid structure of artificial anchorage (10) and super anchor cable (15) is adopted: the root-shaped anchor cable (11) has 10 branches, and the three-level anchorage force distribution ratio is 45%:35%:20%, with the length ratio of each level L1:L2:L3=3.5:2.5:1.5; the transverse anchor beam (14) adopts a box-type steel structure (Q355 steel); the retaining pile (16) adopts a Φ1200mm circular pile; the super anchor cable (15) has an end expansion diameter of 800mm and an expansion section length of 1.5m; the deep end of the pressure anchor rod is equipped with an end expansion structure with an expansion diameter of 1000mm and an expansion section length of 1.5m. After construction, the amount of concrete used is reduced by 92.2% compared with traditional gravity anchorage, the cost is reduced by 76%, the safety factor reaches 2.32, and the deformation of the anchorage system is ≤120mm, which meets the long-term stability requirements of long-span bridges.

[0067] Example 3: Landslide Treatment Project in Fractured Rock Layers

[0068] In a landslide control project involving fractured rock strata, the burial depth of the sliding surface is 15m, and the rock mass is fractured (integrity coefficient Kv=0.3~0.5). Traditional anchoring technology is difficult to meet the stability requirements. The technical solution of this invention is adopted: 12 bundles of root-shaped anchor cables (11) are provided, with a spatial distribution angle of 25°~85° and a horizontal azimuth angle of 30° between adjacent branches; the outer thickness of the convex side is t1=150mm, and the concave side is t2=450mm (t2 / t1=3); the three-level graded anchoring length ratio is L1:L2:L3=3.5:2.5:1.5; the height of the pull-up anchor (3) is 2.5m and the thickness is 1.0m; the included angle α of the anti-buoyancy anchor cable / anchor rod (5) is 35°; all anchor rods / anchor cables are equipped with end expansion structures at the deep ends, with an expansion diameter of 400~1200mm. After construction, a single anchoring force of 50,000 kN was achieved in the fractured rock layer, and the overall displacement was controlled within 150 mm, successfully mitigating the landslide hazard. After one year of monitoring, no significant deformation was observed, effectively ensuring the safety of surrounding structures.

Claims

1. A diagonal anchoring structure based on tree root-like anchors and anti-buoyancy tension, characterized in that: Includes vertical anchor beam (1), anchoring anchor beam (2), pull-up anchor (3), anchor bearing anchor rod (4), anti-buoyancy anchor cable / anchor rod (5), anchoring anchor beam and vertical anchor beam connector (7), ground pile (9), artificial anchor (10), tree root-shaped anchor cable (11), anchor cable wrapped with concrete or mortar material (12), pull-up anchor internal anchor cable (13), horizontal anchor beam (14), super anchor cable (15), retaining pile (16), pile top anchor plate (17), pile top anchor plate anchor hole (18), forward anchor hole (19), reverse anchor hole (20), butt anchor plate (21), ground pile body (22), pile top anchor plate bearing anchor rod (23), pile top anchor plate anchor pad steel plate (24); The artificial anchor (10) is set at both ends of the suspension anchor beam or the reverse tension end of the inclined anchor beam. The side branches are arranged in a spatial radial pattern with 3 to 12 bundles of tree root-like anchor cables (11). The center is set with a middle branch anchor cable extending along the direction of the main cable, which together constitute a three-dimensional anchoring system. The root-shaped anchor cable (11) has branches that bulge into the mountainside to form a bulging side, and the other side is a concave side. The thickness t1 of the concrete or mortar material (12) covering the anchor cable on the bulging side and the thickness t2 on the concave side satisfy t2≥2t1 and t2 / t1=2~40. The upper part of the upper pull anchor (3) is connected to the anchor beam (2) through the anchor, and the anchor beam (2) is fixed to the vertical anchor beam (1) through the anchor beam and vertical anchor beam connector (7); the lower end of the upper pull anchor (3) is connected to the anti-buoyancy anchor cable / anchor rod (5) anchored in the deep stable stratum, and the extension section of the anti-buoyancy anchor cable / anchor rod (5) forms the anchor cable (13) in the upper pull anchor and is eccentrically anchored to the mountain side of the top of the upper pull anchor (3); the mountain side of the top of the upper pull anchor (3) is provided with an anchor bearing anchor rod (4) inclined towards the inside of the mountain, which works with the anti-buoyancy anchor cable / anchor rod (5) to realize the gripping and connection function of the sliding body; The transverse anchor beam (14) is fixed at the corresponding position of the anchor beam (2) and is connected to the upper pull anchor (3) through steel structure and anchor. One or more retaining piles (16) are set on the mountain side of the transverse anchor beam (14). Anchor bearing anchor rods (4) are arranged on the mountain side of the retaining piles (16) and anti-buoyancy anchor cables / anchor rods (5) are set at the bottom, which together form an anti-buoyancy and anti-slip reinforcement system. The ground pile (9) is integrally cast with reinforced concrete by the pile top anchor plate (17) and the ground pile body (22). The pile top anchor plate (17) is provided with curved pile top anchor plate anchor holes (18) and pile top anchor plate anchor pad steel plates (24) are set on both sides of the plane. The ground pile (9) is provided with a connecting anchor plate (21) on the side of the mountain-facing surface. The connecting anchor plate (21) is respectively arranged with forward anchor holes (19) and reverse anchor holes (20) to realize the tensioning and locking of the steel strand and the connection of the force at the break point. End expansion structures are provided at the ends of the root-like branches of the artificial anchor (10), the deep ends of the anti-buoyancy anchor cable / anchor rod (5), the deep ends of the anchor bearing anchor rod (4), and the deep ends of the pile top anchor plate bearing anchor rod (23).

2. The inclined anchorage structure according to claim 1, characterized in that: The height of the upper anchor (3) is 0.3 to 5 m and the thickness is 0.3 to 1.5 m; the angle between the anti-buoyancy anchor cable / anchor (5) and the vertical direction satisfies -10°≤α≤45°.

3. The inclined anchorage structure according to claim 1, characterized in that: The root-shaped anchor cable (11) adopts a three-level anchoring design. The first-level anchoring section bears 40% to 50% of the total anchoring force, the second-level anchoring section bears 30% to 40%, and the third-level anchoring section bears 10% to 20%. The length ratio of each level of anchoring section is L1:L2:L3=(3 to 4):(2 to 3):(1 to 2). The spatial distribution angle of the root-shaped anchor cable (11) is 25° to 135°, and the horizontal azimuth angle of adjacent branches is 30° to 100°.

4. The inclined anchorage structure according to claim 1, characterized in that: The anchoring section of the anchor cable with concrete or mortar material (12) is constructed with a jujube-shaped diameter expansion structure. The maximum diameter in the middle is 30% to 80% larger than the diameter at the end, and the length of the expansion section accounts for 40% to 70% of the total length of the anchoring section.

5. The inclined anchorage structure according to claim 1, characterized in that: The inclined anchor beam anchorage adopts an artificial anchorage (10), a super anchor cable (15) or a combination of the two; the end of the super anchor cable (15) is provided with an expansion structure, the expansion diameter is 600-1200mm, the expansion section length is 1.0-2.0m, and the bearing capacity of a single super anchor cable is 2000-10000kN; the retaining pile (16) is a circular or polygonal pile, used to prevent the transverse anchor beam (14) from floating under stress.

6. The inclined anchorage structure according to claim 1, characterized in that: The diameter of the end-expanding structure is 400–2000 mm, and the length of the expanded section is 1.0–2.0 m.

7. The inclined anchorage structure according to claim 1, characterized in that: The angle range of the anchor hole (18) of the pile top anchor plate is 30° to 90°, and the outer sleeve of the linear section is made of stainless steel corrugated pipe or steel pipe; the plane dimension of the pile top anchor plate (17) perpendicular to the tunnel length direction is 100 to 450cm × 100 to 450cm, and the thickness is 50 to 300cm; the pile top anchor plate (17) is filled with reinforced concrete on the mountain side, and forms a counter-pressure structure with the pile top anchor plate bearing anchor rod (23) to ensure that the foundation on the mountain side and the pile top anchor plate bearing anchor rod (23) are within the design allowable range under the unbalanced pressure generated by the tension of the steel strand.

8. A construction method for a cable-stayed anchorage structure according to any one of claims 1 to 7, characterized in that: The process is divided into two parts: the construction of the anti-sliding end and the construction of the anti-sliding structure within the landslide. The specific steps are as follows: ① Construction of the reverse tension end: tunnel excavation and support → foundation pile (9) pit excavation and foundation pile body (22) pouring → artificial anchor (10) bifurcated excavation and hole wall support → construction of pile top anchor plate (17) and pile top anchor plate anchor pad steel plate (24) → steel strand bundle layout, friction increase treatment for anchor section and friction reduction treatment for free section → artificial anchor (10) and tunnel concrete pouring → construction of pile top anchor plate bearing anchor rod (23) → pile top anchor plate (17) mountain side filling → after the concrete strength reaches the standard, it is tensioned and locked in batches to control the load difference on both sides of the pile top anchor plate (17); ② Construction of anti-slip structure: Drilling and grouting of anti-buoyancy anchor cable / anchor rod (5), reserving a free section of 1.0~2.0m above the bottom of the foundation pit for the upper pull anchor (3) → excavation of foundation pit, horizontal anchor beam (14) groove and retaining pile (16) → construction of anchor bearing anchor rod (4) → waterproof and anti-corrosion treatment of the bottom of anti-buoyancy anchor cable / anchor rod (5) and upper pull anchor (3) → pouring of reinforced concrete for upper pull anchor (3) and retaining pile (16) → after curing to the tension strength, install the anchor beam and vertical anchor beam connector (7), tension and lock the anchor beam (2) → after all vertical anchor beam (1) is connected and tensioned, spiral stirrups are laid on the anchor beam (2) and vertical anchor beam (1) and mortar is injected for anti-corrosion.

9. The construction method according to claim 8, characterized in that: The root-like anchor cable (11) is tensioned according to the four-stage process of "middle branch anchor cable → inner branch anchor cable → outer branch anchor cable → overall over-tensioning". The first stage tensioning is to 30% to 40% of the design value, the second stage tensioning is to 40% to 50% of the design value, the third stage tensioning is to 50% to 60% of the design value, and the fourth stage over-tensioning is to 105% to 110% of the design value. After stabilizing for 3 to 5 minutes, it is locked.

Images