Construction method and structure of embedded anchoring type high-altitude reinforced concrete cantilever footpath

Abstract

This invention discloses a construction method and structure for an embedded anchored high-altitude reinforced concrete cantilever walkway, relating to the field of cantilever walkway construction technology. It includes the following steps: geological survey to determine the anchoring conditions of the rock mass or existing concrete substrate in the construction area; surveying and setting out to determine the installation positions of the cantilever beam components and triangular support frames on the rock mass or existing concrete substrate; using a rebar-bonded anchoring process to sequentially anchor and install the triangular support frames and the cantilever beam components on the rock mass or existing concrete substrate; constructing a full-span support system between the installed cantilever beam components and the triangular support frames; and pouring concrete onto the cantilever beam components to form the cantilever walkway. This invention has wider applicability, is simpler to construct, and ensures operational safety.

Description

Technical Field

[0001] This invention relates to the field of suspended walkway construction technology, specifically to a construction method and structure for an embedded anchored high-altitude reinforced concrete cantilever walkway. Background Technology

[0002] In the fields of mountain tourism development, high-altitude functional expansion of buildings, and landscape facility construction, embedded anchored high-altitude reinforced concrete cantilever walkways have become a key structure for connecting complex terrains and expanding high-altitude spaces due to their core advantages of structural stability and durability, high integration with nature, and unique visitor experience. However, such projects often face pain points such as complex construction environments (cliffs, steep slopes), difficulty in accessing large equipment, high risks of high-altitude operations, and cumbersome traditional support systems. The numerous defects of traditional construction methods further exacerbate these problems.

[0003] The patent with publication number CN113529530A discloses a construction method for a high-altitude cantilever walkway anchored triangular formwork support. It adopts an integrated construction process of triangular cantilever scaffolding and formwork support, which greatly reduces the amount of erection and dismantling work, saves a lot of manpower, machinery and materials, and speeds up the construction period.

[0004] However, the driven anchoring diagonal bar used in this patent is usually only suitable for intact hard rock mass (KV≥0.7). If it encounters moderately weathered fractured rock mass or local strong weathering zone, which are common in scenic areas, the driven steel bar is prone to "slippage" and "loosening". The anchoring force dispersion can reach about ±50%. Moreover, the driven anchoring process at high altitude has a great safety risk. Summary of the Invention

[0005] This invention provides a construction method and structure for an embedded anchored high-altitude reinforced concrete cantilever walkway. The installation and fixation of the triangular support system and cantilever beam components are achieved by anchoring the rebar with adhesive. The process is mature and simple, easy to construct, avoids large-scale construction operations such as driving-in, reduces the safety risks for construction workers, and is applicable to various rock masses with KV≥0.5.

[0006] This invention is achieved through the following technical solution:

[0007] In a first aspect, the present invention provides a construction method for an embedded anchored high-altitude reinforced concrete cantilever walkway, comprising the following:

[0008] Geological survey to determine the anchoring conditions of the rock mass or existing concrete matrix in the construction area;

[0009] Measure and lay out the lines to determine the installation positions of the cantilever beam components and triangular support frames on the rock mass or existing concrete foundation;

[0010] The rebar anchoring process is adopted to sequentially anchor and install the triangular support frame on the rock mass or existing concrete substrate, and to anchor and install the cantilever beam components.

[0011] A full-span support system is constructed between the installed cantilever beam components and the triangular support frame.

[0012] Concrete is poured onto the cantilever beam components to form a cantilever walkway.

[0013] In some alternative implementations, anchoring and installing the triangular support frame includes:

[0014] Drill the first set of anchor bolt holes in the rock mass or existing concrete substrate, inject structural anchoring adhesive into the first set of anchor bolt holes, and insert the first set of anchor bolts. After the anchoring adhesive has cured, connect the vertical and horizontal bars of the triangular support frame to the first set of anchor bolts using fasteners.

[0015] In some optional embodiments, the drilling direction of the first set of anchor bolt holes includes a horizontal direction and an upward direction at an angle of 40° to 50° with the horizontal plane; the lower end of the upright of the triangular support frame is connected to the anchor bolt in the upward direction, and the end of the horizontal rod of the triangular support frame is connected to the anchor bolt in the horizontal direction.

[0016] In some alternative implementations, after the triangular support frame is erected, anchor wire ropes are also installed. One end of the anchor wire rope is connected to the anchor rod anchored to the rock mass, and the other end is connected to the horizontal bar and tensioned to a tension of not less than 5kN.

[0017] In some optional implementations, after the triangular support frame is erected, monitoring equipment is also installed.

[0018] Monitoring sections are set at intervals along the longitudinal direction of the triangular support frame, and monitoring points are set up at corners, ends and areas of concentrated load.

[0019] A monitoring point layer is set on the top surface of the foundation, the sweeping rod layer, the middle of the triangular support frame, and the top operating surface to form a three-dimensional grid;

[0020] Install monitoring equipment at the monitoring points.

[0021] In some alternative implementations, anchoring and installing the cantilever beam member includes:

[0022] An anchoring groove is opened in the rock mass or existing concrete matrix, and a second set of anchor bolt holes is drilled on the wall of the anchoring groove. The second set of anchor bolt holes includes several main force anchor bolt holes with a depth of not less than 1200mm, several auxiliary force anchor bolt holes with a depth of not less than 700mm, and several haunch anchor bolt holes with a depth of not less than 300mm and an upward drilling direction.

[0023] Structural anchoring adhesive is injected into the second set of anchor bolt holes, and the second set of anchor bolts is inserted. After the anchoring adhesive has initially cured, cement grout is injected into the second set of anchor bolt holes and cured to form a permanent anchor.

[0024] The anchoring groove also has an inverted conical groove on its wall.

[0025] In some alternative implementations, the drilling direction of the haunched anchor bolt hole makes an angle of 40° to 50° with the horizontal plane, and the number of haunched anchor bolt holes is 4.

[0026] In some optional implementations, when the rock mass integrity KV ≥ 0.8, the implantation depth of the second set of anchor bolts is configured to be 800 mm;

[0027] When 0.5≤KV<0.8, the implantation depth of the second set of anchor bolts is configured to be 1200mm;

[0028] When KV < 0.5, the second set of anchor bolts is configured with an implantation depth of 1500 mm, and shear keys are connected to them.

[0029] In some alternative implementations, constructing a full-span support system includes:

[0030] Solid wood squares are used as uprights and arranged in a matrix on the triangular support frame. The upper and lower ends of the uprights are fixed to the cantilever beam components or formwork support structure and the triangular support frame by iron nails.

[0031] Along the height of the full-span support system, several tie bars are set at intervals. One end of the tie bar is anchored to the rock mass or existing concrete substrate, and the other end is connected to the uprights or horizontal wooden beams of the full-span support system.

[0032] In some alternative implementations, a safety protection system is also included: angle steel is fixed to the rock mass with expansion bolts, a safety main rope is erected on the angle steel along the extension direction of the walkway, and construction workers wear double-hook safety belts and attach the hooks to the safety main rope.

[0033] In some alternative implementations, the poured concrete is C30 grade or higher concrete mixed with micro-expansion agent and waterproofing agent, with an impermeability grade of not less than P6; after the concrete has set, its surface is roughened by hand to form a rough texture with a depth of 3.2mm to 6.4mm, and a 2% drainage slope is provided.

[0034] In some alternative implementations, geological exploration includes drilling a 50mm diameter borehole at 5m intervals and a depth of 2m to determine that the rock mass integrity coefficient KV is not less than 0.5 or the existing concrete matrix strength is not less than C30.

[0035] In some alternative implementations, the construction of biomimetic railings is also included when forming the cantilever walkway:

[0036] Pre-embedded column reinforcement, permanent and temporary combination: During the stage of binding the slab reinforcement and pouring concrete, the column reinforcement is pre-embedded simultaneously.

[0037] Frame welding: After the main structure of the walkway is completed, the welding positioning of the crossbars and longitudinal bars of the steel frame is adjusted according to the site environment;

[0038] Formwork casting, one-piece molding: Install customized formwork and pour concrete to make the railing and walkway structure form an integral load-bearing system;

[0039] Bionic shaping: The bionic texture of the surface is shaped before the second concrete initial setting;

[0040] Strength testing and finishing: After the concrete reaches the design strength and passes the test, the entire surface is coated with water-based environmentally friendly paint.

[0041] Secondly, the present invention provides an embedded anchored high-altitude reinforced concrete cantilever walkway construction structure, formed by any of the embedded anchored high-altitude reinforced concrete cantilever walkway construction methods described in the first aspect, comprising:

[0042] A fixed foundation is provided, wherein a first set of anchor holes and a second set of anchor holes are provided on the fixed foundation, the first set of anchor holes includes a first inclined anchor hole, and the second set of anchor holes includes a second set of inclined anchor holes;

[0043] The first set of anchor bolts is anchored in the first set of anchor bolt holes;

[0044] The second set of anchor bolts is anchored in the second set of anchor bolt holes;

[0045] A triangular support frame, which is connected to the first set of anchor rods;

[0046] The cantilever beam component is arranged vertically at intervals with the triangular support frame, and the cantilever beam component is connected to the second set of anchor rods by fasteners.

[0047] A full-span support system is anchored to the fixed foundation and located between the cantilever beam member and the triangular support frame to provide support for the upper cantilever beam member.

[0048] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0049] This invention replaces the mechanical driving method of installing triangular support frames and cantilever beams with adhesive-bonded rebar anchoring, reducing reliance on rock mass integrity. It is applicable to a wider range of geological conditions, such as moderately weathered fractured rock masses with KV≥0.5 and locally strongly weathered zones. It overcomes the shortcomings of existing technologies, such as large dispersion of anchoring force and easy slippage and loosening under the same environmental conditions. At the same time, the rebar anchoring process avoids large-scale hammering at heights, simplifies construction operations, effectively reduces the safety risks to construction personnel, and improves the maturity, adaptability, and overall construction safety of the process. Attached Figure Description

[0050] To more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be considered as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort. In the drawings:

[0051] Figure 1 This is a schematic diagram of the construction structure of an embedded anchored high-altitude reinforced concrete cantilever walkway provided in an embodiment of the present invention;

[0052] Figure 2 A partial structural diagram of the anchorage between the outer support and the rock mass provided in an embodiment of the present invention;

[0053] Figure 3 This is a partial structural diagram of the inner upright, the transverse sweeping rod, and the rock mass anchorage provided in an embodiment of the present invention;

[0054] Figure 4 This is a schematic diagram of the construction method for an embedded anchored high-altitude reinforced concrete cantilever walkway provided in an embodiment of the present invention.

[0055] The attached diagram shows the markings and corresponding component names:

[0056] 1-Rock mass, 2-First set of anchor bolts, 3-Second set of anchor bolts, 4-Inner upright, 5-Outer upright, 6-Horizontal bar, 7-Anchor wire rope, 8-Longitudinal sweeping bar, 9-Horizontal sweeping bar, 10-Full-span support system, 11-Guard railing. Detailed Implementation

[0057] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0058] Example 1

[0059] Please refer to the following: Figures 1-4 This embodiment provides a construction method for an embedded anchored high-altitude reinforced concrete cantilever walkway, which mainly includes the following steps:

[0060] Step 1: Construction preparation and geological survey.

[0061] Before construction, a geological survey is conducted. Since cantilever walkways are typically built on cliff faces or the elevated facades of existing buildings, the quality of the rock mass 1 or the concrete matrix directly determines the reliability of the anchoring. In this embodiment, a 50mm diameter, 2m depth borehole is drilled every 5m along the walkway's design direction. By observing the rock core, recording the drilling rate and borehole wall integrity, the integrity coefficient KV of the rock mass 1 is determined. Typically, KV is required to be no less than 0.5, indicating that the rock mass 1 is of a relatively intact or higher grade. When the walkway needs to be connected to an existing concrete structure, the existing concrete strength must be no less than C30. If the survey reveals localized fractures or weak interlayers in the rock mass 1, the anchor depth can be adjusted or shear-resistant measures can be added during subsequent anchoring construction.

[0062] Meanwhile, prepare the materials and equipment required for construction: Φ48.3×3.6mm Q235 steel pipe (tensile strength ≥375Mpa, wall thickness deviation ≤0.3mm), fasteners (bolt torque 40~65N・m, anti-slip bearing capacity ≥7kN), HRB400E grade anchor rods (diameter 18~22mm, tensile strength ≥400MPa, elongation after fracture ≥16%), Class A structural rebar adhesive (colloidal tensile strength ≥30MPa, bond strength ≥11MPa), torque wrench (range 0~100N・m), anchor drilling rig, pneumatic pick, vibrator, theodolite, RTK measuring instrument, level, C30 micro-expansion concrete (28d compressive strength ≥30MPa, impermeability grade ≥P6), etc.

[0063] The transportation of materials and equipment can be carried out through a combination of freight cableway transport and manual transport. Freight cableway transport is suitable for cliffs and areas with a slope greater than 30°. The cableway has a rated load capacity of ≥5kN, a bucket size of 0.5m³, and rubber pads lining the inner wall. Sealed buckets are used when transporting concrete. The tower foundation is made of C25 concrete, fixed with pre-embedded anchor bolts, and the steel wire rope is 6×19S+FC-15.5mm. The safety factor calculation includes a dynamic load factor of 1.2, and the overall safety factor is ≥3. A warning zone is set up below the transport route. Three no-load test runs and one loaded test run are conducted before each daily transport. Formal transport can only proceed after no abnormalities are found. Manual transport is suitable for areas with a slope ≤30°. Electric tricycles, backpacks, and carrying baskets are used in conjunction with construction access roads to transport materials to the construction site. Each transport should carry ≤3 steel pipes or ≤20 fasteners. Non-slip shoes and gloves should be worn, and temporary handrails should be provided on steep sections. Temporary transfer platforms were set up in different sections of the construction site. Materials were stacked in categories. Steel pipes and fasteners were stacked to a height of ≤1.5m. Chemicals were stored in cool, dry places, and materials that were susceptible to moisture were raised and covered.

[0064] Step 2: Measurement and layout.

[0065] Using an RTK surveying instrument or total station, accurately lay out the center line, edge line, and anchor hole positions for each cantilever beam on the surface of rock mass 1. Cantilever beams are typically installed every 2.5m along the walkway direction. Simultaneously, lay out the upright positions and anchor hole positions of the triangular support frame 1.0m to 1.2m below the designed location of the cantilever beam. Control the coordinate deviation of each elevation benchmark point to within ±3cm, and the elevation deviation to within ±3cm.

[0066] Step 3: Anchoring and erection of the triangular support frame.

[0067] First, the first set of anchor bolt holes is drilled in rock mass 1. Based on the surveyed and laid-out positions, an anchor bolt drilling rig is used for drilling. Before drilling, loose soil and rock fragments within 1m of the anchor point are cleared, and the rock surface is washed with high-pressure water to ensure the anchor surface is dry and clean. Cracks ≥5mm wide are cleaned with a high-pressure air gun and then sealed with epoxy resin. To meet the stress requirements of the triangular support frame, the drilling direction is divided into two categories: one is horizontal (or nearly horizontal), mainly used to bear the horizontal tension transmitted by the transverse rod 6; the other is obliquely upward, with an angle of approximately 45°±3° to the horizontal plane, mainly used to bear the oblique pressure transmitted by the vertical rod. The drilling diameter is typically 22~28mm, and the depth is not less than 250mm (allowable deviation ±20mm). After drilling, the angle is checked with a goniometer, and dust and debris inside the hole are cleaned with a high-pressure air gun or high-pressure water gun, with the water depth inside the hole controlled to within 10mm.

[0068] Next, apply the anchoring adhesive. Use Grade A structural anchoring adhesive, mix it according to the specified ratio, and mechanically stir for at least 3 minutes until the color is uniform and there are no air bubbles. Use a special syringe to inject the anchoring adhesive into the drilled hole, with the amount of adhesive approximately 1.2 times the volume of the drilled hole, to ensure that the adhesive completely fills the gaps after the anchor is inserted. Apply a thin layer of anchoring adhesive to the surface of the pre-cut HRB400E rebar (diameter 18~22mm, length usually not less than 500mm), slowly screw it into the bottom of the hole at a rotation speed of 10r / min, inserting it to a depth of 250mm, and rotate it 2~3 times to ensure the adhesive evenly coats the anchor. Let it stand for at least 30 minutes to allow the anchoring adhesive to initially cure. During this period, do not disturb the anchor. If the anchor becomes loose, add more anchoring adhesive and re-insert it. After the anchoring adhesive has completely cured, use a torque wrench to check to ensure that the anchoring force is not less than 10kN.

[0069] Next, install the triangular support frame. Connect the lower ends of the outer uprights 5 and the inner uprights 4 to the upward-sloping anchors using right-angle couplers (i.e., the bottom of the upright is fitted onto the exposed section of the anchor and locked with couplers). The longitudinal spacing of the uprights is 1.5m, and the transverse spacing is 1.2m. The other ends of the outer uprights 5 and the inner uprights 4 are connected to the transverse bars 6, forming a triangular stable structure. Then install the longitudinal sweeping bars 9 and the transverse sweeping bars 10, with one end of the transverse sweeping bars 10 anchored to the rock mass 1 to limit slippage at the base of the frame. Install the horizontal transverse bars 6, connecting one end of the transverse bars 6 to the horizontal anchors using right-angle couplers, and the other end to the inner uprights 4 and the outer uprights 5. The spacing between adjacent transverse bars 6 is 1.8m. Erect longitudinal bars on the transverse bars 6, with the joints of adjacent longitudinal bars and transverse bars 6 staggered by no less than 500mm, forming a protective system. A 2.5m high protective railing 12 is erected on the side away from the rock mass 1. All fastener bolts are tightened to 40~65 N·m using a torque wrench to ensure that the anti-slip bearing capacity of a single fastener is not less than 7kN.

[0070] In addition, to improve the ability to resist horizontal wind loads, anchor wire ropes 7 can be added. One end of the wire rope is fixed to the exposed end of the horizontal anchor rod with a U-shaped buckle, and the other end is connected to the transverse rod 6 with a turnbuckle, and tensioned to a tension of not less than 5kN. In this way, the triangular support frame and the rock mass 1 form a rigid and flexible dual connection, which greatly improves the overall stability.

[0071] After the triangular support frame is erected, the next step is to install monitoring equipment.

[0072] Monitoring sections are set at intervals along the longitudinal direction of the triangular support frame, and monitoring points are set up at corners, ends, and areas with concentrated loads; the spacing between adjacent monitoring sections is usually 10~15m.

[0073] A monitoring point is set on the top surface of the foundation, the sweeping rod layer, the middle of the triangular support frame, and the top operating surface to form a three-dimensional grid.

[0074] Monitoring equipment is installed at the monitoring points. Specifically, this may include installing an axial force gauge at the bottom of the inner pole 4, installing an inclination sensor and a GNSS / displacement gauge at the top of the outer pole 5, and installing a static level around the foundation.

[0075] After the monitoring equipment is installed, the monitoring frequency should be set, generally according to the following standards:

[0076] During normal construction periods: the frequency of automated data collection is once every 30 minutes; the frequency of manual retesting is once per day.

[0077] During the pouring / loading period: the automatic data acquisition frequency is once every 5 minutes; the manual retesting frequency is real-time on-site monitoring.

[0078] After heavy rain / strong winds: the automatic data collection frequency is once every 5 minutes (lasting for 2 hours); the manual retesting frequency is immediate retesting.

[0079] When data is abnormal: the automatic collection frequency is 1 time / 1min (encrypted tracking); the manual retest frequency is immediate verification.

[0080] Upon obtaining monitoring results, timely countermeasures should be taken, generally in accordance with the following provisions:

[0081] A yellow alert is issued when the horizontal displacement is ≥8mm, the vertical settlement is ≥10mm, and the tilt rate is ≥H / 300. Work should be suspended, the cause investigated, and monitoring intensified.

[0082] When the horizontal displacement is ≥12mm, the vertical settlement is ≥15mm, and the tilt rate is ≥H / 200, an orange alert is issued, and personnel should be evacuated, unloaded and reinforced, and an expert assessment should be conducted.

[0083] A red alert is issued when the horizontal displacement is ≥16mm, the vertical settlement is ≥20mm, and the tilt rate is ≥H / 150. Work should be stopped and the area sealed off immediately, and the emergency plan should be activated.

[0084] This embodiment replaces the traditional method of driving in reinforcing bars and bending them with adhesive anchoring. The anchoring force can be quantified and has low dispersion, with measured dispersion less than 5%. The fastener connection allows for fine-tuning of the member angle within ±5°, resulting in high installation accuracy. The member angle deviation can be controlled within ≤2°, and the verticality deviation of the frame can be controlled within ≤4mm. The construction process eliminates the need for dangerous actions such as large hammer swings and prying, significantly reducing the risk of working at heights. Furthermore, the anchor rods of the triangular support frame can be retrieved using a special rod puller after construction. Compared to existing hammer-driven anchoring methods, this embodiment reduces anchoring material costs by approximately 38%, meeting the requirements of green construction.

[0085] Step 4: Anchoring of cantilever beam components.

[0086] First, anchoring trenches are dug in rock mass 1. Using a pneumatic pick, the trenches are dug in layers, each layer no deeper than 200mm, ultimately forming an anchoring trench 600mm long, 300mm wide, and 300mm deep. The surface soil is cleared, and the trench is leveled according to design requirements, leaving space for the edge formwork operation. After chiseling, a 100mm thick C15 concrete base layer is poured to seal the bottom. The trench walls are chiseled with a 5mm deep texture to enhance the embedding effect of the later concrete. The trench is cleaned of gravel and dust using a high-pressure air gun and water gun. After cleaning, ensure the water depth at the bottom of the trench is ≤5mm. If the target of the trench is a building, a 20mm thick layer of M15 cement mortar is laid at the bottom for leveling, and after curing for 24 hours, the strength is ensured to be ≥10MPa.

[0087] Next, drill the second set of anchor bolt holes. The second set of anchor bolt holes includes: 5 main load-bearing anchor bolt holes, 25-28mm in diameter, drilled horizontally, with a depth of not less than 1200mm; 2 auxiliary load-bearing anchor bolt holes, 25-28mm in diameter, with a depth of not less than 700mm; and 4 haunch anchor bolt holes, 22-25mm in diameter, drilled upwards at an angle of 45°±5° to the horizontal plane, with a depth of not less than 300mm. If rock fissures are encountered, additional drilling is required. After drilling, flush the holes with high-pressure water (0.4MPa) to remove any residue, then dry them with a high-pressure air gun, ensuring that the water accumulation in the holes is ≤10mm and the dust thickness is ≤2mm.

[0088] After drilling is completed, a three-blowing, two-brushing, and one-cleaning process is performed to clean the dust, oil, and water inside the hole and check the quality of the hole wall. Subsequent work can only proceed after verifying that the different hole diameters and depths are qualified. Before construction, the quality of the adhesive is checked, and unqualified materials are eliminated. Components A and B are strictly mixed in a 2:1 ratio, and mechanically stirred for at least 3 minutes until the adhesive is uniform and free of air bubbles. The adhesive is used immediately after mixing, and the construction time is strictly controlled. Then, a special syringe is used to inject the adhesive evenly from the bottom of the hole upwards at a rate of 1.2 times the drilling volume. For 1200mm deep holes, a layered adhesive injection and venting process is adopted to ensure that the adhesive fills the hole fully and densely. A 50mm tapered guide head is machined at the end of the anchor rod. After applying a thin layer of anchoring adhesive to the anchoring section, it is slowly inserted into the hole and rotated 2-3 times to ensure the adhesive is fully absorbed. Evenly wrap the anchor rod and fit it against the hole wall. After the rebar is installed, let it cure at room temperature for 1 hour and take proper positioning protection. During the curing period, the anchor rod must not be disturbed. After construction, use geotextile to keep it moist for no less than 7 days. During the curing period, protect the finished product and prevent the anchor rod from being subjected to force or impact. After completion, sample 3% of each batch, with a minimum of 3 rods, to carry out pull-out tests. The pull-out force of anchor rods with an implantation depth ≥1200mm must be ≥80kN, and the pull-out force of anchor rods ≥700mm must be ≥50kN. Unqualified samples should be retested twice. If the retest fails, the entire batch should be reworked immediately. In this embodiment, the rebar installation adopts a pure glue anchoring process, eliminating the need for secondary cement grouting, effectively avoiding quality risks such as glue slurry delamination and interface debonding, and ensuring stable and reliable rebar anchoring.

[0089] The second set of anchor bolts, typically 22mm and 20mm in diameter, are inserted into the second set of anchor bolt holes. The insertion depth of the second set of anchor bolts can be adjusted adaptively based on different rock mass integrity coefficients. For hard rock with KV ≥ 0.8, the insertion depth of the 22mm diameter second set of anchor bolts is configured to 800mm, and the insertion depth of the 20mm diameter second set of anchor bolts is configured to 600mm. For softer rock with KV ≤ 0.8, the insertion depth of the 22mm diameter second set of anchor bolts is configured to be no less than 1200mm, the insertion depth of the 20mm diameter second set of anchor bolts is configured to be no less than 700mm, and the insertion depth of the 16mm diameter second set of anchor bolts is configured to be no less than 300mm. Additionally, an additional anchor bolt is added at the bottom of the anchoring groove. Two inverted conical grooves are used to enhance the transmission of vertical shear force. The depth of the inverted conical grooves is 50mm and the maximum diameter is 100mm. For soft rock with KV < 0.5, a steel plate with dimensions of 100mm*100mm*8mm should be welded and fixed on the second set of anchors as a shear key. At the same time, the anchor groove size is enlarged to 800mm*400mm*400mm. The second set of anchors with a diameter of 22mm is configured to be implanted at a depth of 1500mm, and the second set of anchors with a diameter of 20mm is configured to be implanted at a depth of 900mm.

[0090] The cantilever beam should adopt a variable cross-section design. The standard cross-section of the cantilever beam is 600mm high at the root (including the slab thickness), 350mm high at the end, and a transition section length of 500mm (smooth arc). The following should be used as the basis for adjusting the width:

[0091] Root width (mm) = 250 + 50 × cantilever length (m) + 30 × (walkway width - 2.0m);

[0092] End width (mm) = 200 + 50 × cantilever length (m) + 30 × (walkway width - 2.0m).

[0093] For the reinforcing bars in cantilever beams, it is preferred to use whole-length reinforcing bars for the cantilever load-bearing structure, and lap splicing is strictly prohibited. If a connection is necessary under special conditions, welding should be used. The effective weld length on one side should be ≥10d, and the effective weld length on both sides should be ≥5d (d is the diameter of the reinforcing bar). The weld thickness should be ≥6mm to ensure the reliable stress of the welded joint. The main reinforcing bars of the beam should preferably be connected by equal-strength ribbed and rolled straight thread, with the joint grade being Grade 1. The percentage of joint area in the same connection section should be ≤50%. Joints should not be located in the stirrup-reinforced areas at the beam ends and column ends. If it is impossible to avoid them, the percentage of joint area should be strictly controlled to ≤50%. The straight thread must be full and intact, without broken or bare teeth. It should be inspected and accepted item by item using a thread gauge and caliper. Qualified threads should be protected with protective caps. During construction, ensure that the reinforcing bar specifications match the connecting sleeve. Screw the sleeve smoothly into the axis, with no more than one turn of thread exposed on each end of the sleeve. Strictly control the construction quality of the reinforcing bar connection. PVC pads are used on the bottom of beams and slabs, and plastic clips are used on the sides. The spacing between the pads is ≤1000mm, arranged in a quincunx pattern. Column spacing frames (which can be reused) are set at the top of columns, and two limiting stirrups are tied on the outside to control the spacing of the reinforcing bars.

[0094] In this embodiment, the cantilever beam anchor rods are anchored with rebar adhesive, which has high pull-out resistance and is reliable. The 45° upward slope design of the haunch anchor rods directly resists the huge shear force at the root of the cantilever beam, making the stress distribution more reasonable. The roughening and inverted conical groove in the anchoring groove further enhance the bonding between the concrete and the rock mass 1, eliminating the need for additional shear keys and simplifying the process.

[0095] Step 5: Construction of the full-span support system 11.

[0096] After the cantilever beam component is anchored, a full-span support system 11 needs to be built between it and the triangular support frame below to bear the construction load when the upper concrete is poured.

[0097] Before erecting the full-span support system 11, lay 30mm thick and 160mm wide solid wood planks on the working surface at the top of the triangular support system. The planks should be at least 2000mm long and the horizontal spacing should be controlled at 300mm. The planks should be fully laid, flat, and firmly fixed with nails. The plywood should be fixed to the lower wooden planks point-to-point with nails at a spacing of ≤300mm to ensure that the working surface is flat, solid, and has sufficient load-bearing capacity and anti-slip performance to meet the needs of construction personnel and material stacking. Lay a 50mm thick continuous wooden plank on the wooden plank as a foundation. Fix the planks to the horizontal bars 6 of the triangular support system with nails, with no less than 2 nails per meter. The joints of the planks must be located on the horizontal bars 6. Then lay a 15mm thick plywood layer on the planks to form a flat and solid full-span scaffold foundation surface.

[0098] In this embodiment, the uprights of the full-span support system 11 are made of 60mm×80mm solid wood, instead of traditional steel pipes. Wood has advantages such as light weight, ease of high-altitude transport and cutting, and convenient connection to the formwork. The wood uprights are arranged in a 500mm×500mm matrix grid on the triangular support frame. In areas with concentrated loads, such as the base of the cantilever beam, the spacing between the uprights is increased to 400mm. The upper and lower ends of the uprights are fixed to the upper cantilever beam formwork support timber and the lower triangular support frame horizontal bars 6 using continuous anti-corrosion iron nails (≥50mm in length), with at least two nails at each node.

[0099] Along the height of the scaffolding, tie bars should be installed every 1000mm. The tie bars should be made of 16mm diameter HRB400 steel bars, with one end embedded in the rock mass to a depth of ≥250mm, and the other end securely tied to the uprights or horizontal timbers of the scaffolding using wire or fasteners. The tie bars should be arranged symmetrically to limit horizontal displacement of the scaffolding.

[0100] Finally, a horizontal wooden beam is installed at the top of the upright, and a 15mm thick film-coated plywood is laid as the bottom formwork.

[0101] In this embodiment, the wooden uprights are lightweight, making it easy for manual operation on cliffs; the dense arrangement and continuous iron nail fixation ensure reliable force transmission at the nodes; the rock mass 1 tie bar connects the full-span frame to the mountain as a whole, with strong resistance to horizontal displacement, and the horizontal displacement of the frame can be controlled within 8mm.

[0102] Step 6: Concrete pouring and surface treatment of the cantilever walkway.

[0103] The concrete used in this embodiment is C30 micro-expansion waterproof concrete. The specific mix proportions are: P.O42.5R cement, with 0.02% micro-expansion agent and a composite waterproofing agent added. The concrete slump is controlled at 120-140mm, and the impermeability grade reaches P6 or higher. During pouring, the concrete is poured in layers from the cantilever end to the anchorage end, with each layer not exceeding 400mm in thickness, and compacted using a Φ35mm immersion vibrator.

[0104] After the concrete has set (usually 28 days after pouring), it is manually roughened. A pneumatic pick or hand-held roughening machine is used to create a uniform rough texture on the surface of the walkway, with the depth controlled between 3.2mm and 6.4mm. At the same time, the slope of the formwork is controlled during concrete pouring to create a 2% drainage slope on the surface of the walkway, sloping towards the outside of the walkway. Cover with geotextile within 12 hours after pouring, and water for curing for ≥7 days, watering ≥4 times a day; Low temperature curing (<5℃): Cover with geotextile and insulation blanket, and add composite antifreeze (chloride ion content ≤0.06%); High temperature curing (≥35℃): Adjust the working time to 6:00-11:00 and 15:00-19:00 to avoid high temperature periods, cover with shade cloth, add retarder, the retarder is calcium lignosulfonate, the dosage is 0.2%~0.3% of the cement dosage, cover the formwork surface with moisture-retaining felt to avoid the concrete surface from losing water too quickly and causing cracks, and water once every 2 hours; Monitor temperature and humidity during curing; Low temperature curing (≥5℃): Cover with geotextile and insulation blanket (thermal conductivity ≤0.04W / (m・K)).

[0105] When constructing concrete in winter, a chloride-free composite antifreeze agent (FH-9 or JDF-2 type, containing calcium nitrite and magnesium nitrate) is used, combined with an organic-inorganic composite early-strength agent (triethanolamine 0.02%~0.05% + sodium sulfate 1%~2%), suitable for construction environments of -8℃ in winter. The dosage of antifreeze agent is 1.5%-2.0%, the dosage of early-strength agent is 1.5%-2.0% (sodium sulfate dosage ≤2.5%), and the chloride ion content is controlled at 0.05%. When mixing, the powdered additive is first dry-mixed with medium sand for 2-3 minutes, and then the materials are added in the following order: dry-mixed sand, additive, P.O42.5R cement, crushed stone, and water added in stages (add 80% first, and adjust the remaining 20% ​​as needed). The mixing time is extended by 50% compared with the normal temperature and the total time is ≥3 minutes to ensure that the mixture is uniform and free of lumps. The pouring time should be selected between 10:00 and 15:00, during periods of higher air temperature (-2℃ to 5℃). The slump should be controlled at 130~140mm to avoid low-temperature segregation. The temperature upon entering the formwork should not be lower than 10℃. This temperature should be ensured by preheating the aggregate or mixing with hot water at ≤65℃ (if the water temperature exceeds 65℃, mix the hot water with the aggregate first to cool it down before adding the cement). The pouring time should be selected between 10:00 and 15:00 (during periods of higher air temperature).

[0106] After pouring, common concrete defects should be prevented: the formwork should be thoroughly cleaned, the release agent applied evenly, and the concrete compacted in layers; for pitted areas, moisten with water and smooth with mortar of the original mix proportion without aggregate. Fine aggregate concrete should be used in areas with dense reinforcement, and each layer should be carefully vibrated; small honeycombs should be smoothed with 1:2.5 cement mortar, and large honeycombs should be filled with higher-grade fine aggregate concrete after removing loose concrete. Before pouring, a 10cm thick layer of cement mortar of the same mix proportion should be poured first, controlling the concrete slump, and the lower part should be vibrated properly. One set of standard curing test blocks should be prepared for every 100 batches (not exceeding 100m³), and one set of impermeability test blocks should be reserved for every 500m³; at least two sets of test blocks under the same conditions should be used for demolding determination at 75% and 100% strength, respectively.

[0107] In this embodiment, the self-waterproofing of the concrete body replaces the traditional waterproof membrane, and manual roughening and drainage slope replace anti-slip floor tiles. The two processes are combined into one, saving approximately 60,000 yuan per 100m of boardwalk. The dry friction coefficient of the roughened boardwalk surface is ≥0.6, and the wet friction coefficient is ≥0.4, meeting the requirements for safe walking.

[0108] In some optional embodiments, the construction of biomimetic railings is also included when forming the cantilever walkway, specifically including the following:

[0109] Pre-embedded column reinforcement, permanent and temporary combination: During the stage of binding the slab reinforcement and concrete pouring, the column reinforcement is pre-embedded simultaneously.

[0110] The reinforcing bars for the columns can be Φ10 with a height of 1.2m, and the number of reinforcing bars in a single column is usually 4. After pre-embedding, additional reinforcement can be used for locally confined areas. This column reinforcement system combines temporary protection during construction with permanent railing during operation, effectively ensuring construction and process safety.

[0111] Frame welding: After the main structure of the walkway is completed, the welding positioning of the crossbars and longitudinal steel reinforcement frame is adjusted according to the site environment.

[0112] The site environment mainly consists of tree distribution and terrain conditions. This step is primarily to ensure that the spacing meets national standards while also considering both protective functions and landscape harmony.

[0113] Formwork casting, one-piece molding: Install customized formwork and pour concrete to make the railing and walkway structure form an integral load-bearing system.

[0114] Bionic Shaping: The surface bionic texture is shaped before the second concrete initial setting to ensure a natural and realistic shape.

[0115] Strength testing and finishing: After the concrete reaches the design strength and passes the test, the entire surface is coated with water-based environmentally friendly paint to improve durability and appearance.

[0116] The biomimetic railing construction process provided in this embodiment, compared to the conventional post-reinforced railing process, is as follows:

[0117] Strong structural integrity: The railings and walkways are poured simultaneously, avoiding damage to the original structure and potential anchoring reliability issues caused by post-installation of reinforcing bars.

[0118] The process is safe and controllable: the pre-embedded steel bars also serve as protection during construction, eliminating the safety gap in the traditional process of "removing temporary protection first and then installing permanent railings".

[0119] Better overall benefits: Reduces secondary site visits and rebar installation, shortens construction period, and reduces total life cycle costs.

[0120] Example 2

[0121] Based on Example 1, this example optimizes and supplements some key structures to further improve construction efficiency and safety.

[0122] In some alternative embodiments, due to the involvement of high-altitude cliff work, the risk of personnel falling is extremely high. Therefore, safety protection systems are prioritized for installation before the formal erection of the triangular support frame. Specifically:

[0123] On the rock mass 1, 2-3m above the walkway working surface, an anchor point is set at intervals no greater than 2.5m along the walkway direction. Each anchor point uses L-shaped angle steel (150mm×150mm×3mm) and two sets of expansion bolts (10mm or 12mm in diameter, 120mm in length) to fix the angle steel to the rock wall. A round hole is made or an anchor ring is welded to the other side of the angle steel. A 10mm diameter steel wire rope is passed through all the anchor rings of the angle steel, and the steel wire rope is connected and fixed in sections using U-shaped steel rope clips to form a continuous safety main rope.

[0124] Construction workers must wear five-point double-hook safety harnesses. During operation, the two safety hooks are alternately attached to the main safety rope, ensuring at least one hook remains connected to the main rope at all times during movement. At the junction of two wire rope segments, the open-type anchor ring design allows the hook to slide into the next segment of the main rope without being removed, achieving seamless protection throughout the entire process.

[0125] The design tensile bearing capacity of a single expansion bolt shall not be less than 5kN, and the overall safety factor of the safety rope shall be greater than 3. This safety rope system shall remain effective throughout the entire process of erecting the triangular support frame, anchoring the cantilever beam, and pouring concrete, and shall not be removed until all high-altitude operations are completed.

[0126] In some optional embodiments, in the construction of the triangular support frame in Embodiment 1, one end of the anchor wire rope 7 is fixed to a horizontal anchor rod, and the other end is connected to the transverse rod 6. To facilitate tension adjustment, turnbuckles should be connected in series in the middle. Specifically, during tensioning, a tension gauge is used to tighten the wire rope, ensuring that the tension force is not less than 5kN to improve the lateral stiffness of the triangular support frame.

[0127] Example 3

[0128] This embodiment mainly describes the dismantling work after the completion of the trestle construction.

[0129] 1. Demolition conditions

[0130] Side formwork removal: Concrete strength ≥ 2.5MPa, no damage to edges and corners; Bottom formwork / scaffolding removal: Concrete strength reaches 100% of design strength, no deformation or cracks (cracks ≤ 0.2mm).

[0131] Standard for side formwork removal: The concrete surface and edges should not be damaged during formwork removal.

[0132] The basis for removing the bottom formwork must be the strength report of the test block cured under the same conditions. Removing the formwork based on experience is strictly prohibited.

[0133] Crack inspection: Before demolition, check the concrete surface for cracks. If the crack width exceeds 0.2mm, the cause must be identified and addressed before demolition can proceed.

[0134] 2. Demolition sequence

[0135] Strictly follow the top-down procedure: Guardrail 12 → Side formwork → Wooden plank → Bottom formwork → Horizontal bar → Vertical bar → Frame anchor rod recovery → Safety rope removal.

[0136] Segmented dismantling control: The height difference between segments of dismantling shall not exceed 2 steps. For scaffolding that is not dismantled, wall ties and horizontal diagonal braces shall be installed at both ends for reinforcement.

[0137] Safety during operation: During the demolition process, it is strictly forbidden to work at different levels simultaneously, and it is strictly forbidden to throw materials.

[0138] Material transportation: Dismantled templates, steel pipes, fasteners and other materials must be hoisted to the ground with ropes and stacked neatly according to their categories.

[0139] Regarding the removal of the safety rope:

[0140] Timing of removal: The safety rope can only be removed after the entire tripod has been dismantled and all workers have evacuated. Removal in advance is strictly prohibited.

[0141] Dismantling sequence: First, release the tension of the turnbuckles → remove the wire rope → remove the angle steel and expansion anchors.

[0142] Component recycling: Dismantled steel wire ropes, angle steel and other components are sorted and recycled. After inspection for integrity, they can be reused. Steel wire ropes that are severely rusted or have broken wires must be scrapped.

[0143] Safety during dismantling: When dismantling the safety main rope, workers must wear safety belts and attach them to a secure anchor point.

[0144] Hole treatment: The holes of the removed expansion anchors are sealed and smoothed with cement mortar.

[0145] Scrapping criteria: Steel wire ropes that are severely rusted or have more than 10% broken wires must be scrapped and cannot be reused.

[0146] Example 4

[0147] This embodiment provides an embedded anchored high-altitude reinforced concrete cantilever walkway construction structure, formed by any of the embedded anchored high-altitude reinforced concrete cantilever walkway construction methods described in the first aspect, including:

[0148] A fixed foundation is provided, wherein a first set of anchor holes and a second set of anchor holes are provided on the fixed foundation, the first set of anchor holes includes a first inclined anchor hole, and the second set of anchor holes includes a second set of inclined anchor holes;

[0149] The first set of anchor bolts 2 is anchored in the first set of anchor bolt holes;

[0150] The second set of anchor bolts 3 are anchored in the second set of anchor bolt holes;

[0151] A triangular support frame, which is connected to the first set of anchor rods 2;

[0152] The cantilever beam component is arranged vertically at intervals with the triangular support frame, and the cantilever beam component is connected to the second set of anchor rods 3 by fasteners.

[0153] The full-span support system 11 is anchored to the fixed foundation and located between the cantilever beam member and the triangular support frame to provide support for the upper cantilever beam member.

[0154] In summary, this invention uses a rebar anchoring process to achieve anchor bolt fixation, eliminating the need for high-altitude hammering and the process of prying and twisting the rebar with steel pipes, thus improving the safety of construction workers. The rebar anchoring process is relatively complete, easy to implement, and applicable to various rock masses with KV≥0.5. Furthermore, in existing technologies using twisted rebar for fixing, the installation angle of the rods is not adjustable, and the maximum deviation of the rods during installation can reach 12°, causing the force on the triangular frame to deviate from the design axial force direction, with the actual bearing capacity only 60%-70% of the theoretical value. In contrast, the anchor bolts in this invention are connected to the vertical and horizontal rods using fasteners, allowing for precise fine-tuning of the rod angle within a ±5° range, ensuring the geometric accuracy of the triangular structure and that the force fully conforms to the design calculation model. Furthermore, the driven steel bars in the existing technology are disposable and cannot be recycled. According to the inventor's experience, about 15.6 kg of steel is wasted for every 10m of boardwalk. The anchor rods of the triangular support system of the present invention can be recycled through a special rod puller, with a recycling rate of ≥90% and a reuse count of ≤3 times, which is in line with the construction concept of "minimal ecological disturbance" in mountain scenic areas.

[0155] This invention eliminates the need for the inclined anchor cables in existing technologies through multi-dimensional collaborative optimization design of the triangular support system's structural parameters, connection methods, and tie reinforcement. Specifically, this invention optimizes the arrangement parameters of the uprights (i.e., longitudinal spacing of 1.5m and transverse spacing of 1.2m) and the arrangement parameters of the transverse members 6 (step distance of 1.8m), making the triangular support system itself a geometrically invariant system with an overturning resistance coefficient ≥1.4 and a transverse member deflection ≤L / 150, capable of independently bearing more than 90% of the vertical load and 70% of the horizontal load. Simultaneously, each triangular support system employs no fewer than three anchor rods (i.e., anchor rods corresponding to the inner upright 4, outer upright 5, and transverse member 6), which are directly and rigidly connected to the uprights and transverse members 6 via right-angle couplers. The bolt torque is 40~65 N·m, and the single coupler's anti-slip bearing capacity is ≥7kN. Furthermore, a rigid connection point is added every 2.5m to the transverse members 6, using double couplers for fixation, further limiting the horizontal displacement of the frame. Furthermore, a Φ10mm horizontal anchor steel wire rope 7 is installed every 2.5m, with a tension force ≥5kN, connecting the transverse rod 6 of the triangular support system to the rock mass 1 anchor rod, providing overall horizontal ties; the top and bottom of the triangular support system can be fully equipped with continuous horizontal scissor bracing, forming an angle of 45° with the rock mass 1, spanning 5~7 uprights, with an overlap length of 1m, and fixed with 3 swivel couplers, so that each triangular frame forms an integral load-bearing unit. In addition, a Φ16mm steel bar tie is installed every 1000mm along the height of the full-span scaffold (embedded in the rock mass 1 ≥250mm, with a pull-out force ≥5kN), further enhancing the overall stability. Through the above-mentioned multi-dimensional optimization design, the use of inclined anchor cables in existing technologies is eliminated, which can eliminate the dangerous operation of climbing and installing anchor cables at heights, reducing the risk of high-altitude work accidents by about 60%. The rigid connection system eliminates the risk of corrosion and wire breakage, resulting in higher structural reliability. The four processes of anchor cable drilling, installation, tensioning, and removal are omitted, shortening the construction period of each 10m walkway by about 1.2 days. The total construction period of a 100m walkway is shortened from 50 days in the traditional method to 30 days, a reduction of 40%. Without anchor cable obstruction during construction, the efficiency of formwork installation and concrete pouring is improved by more than 30%. In addition, from an overall structural perspective, the horizontal displacement of the triangular support system is controlled within 8mm, far superior to the 25mm warning value in existing technologies; the overall stress distribution is more uniform, with no local stress concentration; and the wind resistance is improved from level 6 to level 8, making it more suitable for strong wind environments in mountainous areas.

[0156] The above specific embodiments further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A construction method for an embedded anchored high-altitude reinforced concrete cantilever walkway, characterized in that, Includes the following: Geological survey to determine the anchoring conditions of the rock mass (1) or existing concrete matrix in the construction area; Measure and lay out the lines to determine the installation positions of the cantilever beam components and the triangular support frame on the rock mass (1) or the existing concrete matrix; The anchoring process is adopted to anchor and install the triangular support frame in sequence on the rock mass (1) or the existing concrete base, and to anchor and install the cantilever beam components. A full-span support system is built between the installed cantilever beam components and the triangular support frame (11). Concrete is poured onto the cantilever beam components to form a cantilever walkway.

2. The construction method for an embedded anchored high-altitude reinforced concrete cantilever walkway according to claim 1, characterized in that, Anchoring and installing the triangular support frame includes: Drill the first set of anchor holes in the rock mass (1) or the existing concrete matrix, inject structural anchoring adhesive into the first set of anchor holes, and insert the first set of anchors (2). After the anchoring adhesive has cured, connect the uprights and horizontal bars (6) of the triangular support frame to the first set of anchors (2) using fasteners.

3. The construction method for an embedded anchored high-altitude reinforced concrete cantilever walkway according to claim 2, characterized in that, The drilling directions of the first set of anchor bolt holes include the horizontal direction and the oblique upward direction at an angle of 45°±3° to the horizontal plane; The lower end of the upright of the triangular support frame is connected to the anchor rod in the upward direction, and the end of the horizontal rod (6) of the triangular support frame is connected to the anchor rod in the horizontal direction.

4. The construction method for an embedded anchored high-altitude reinforced concrete cantilever walkway according to claim 3, characterized in that, After the triangular support frame is erected, it also includes setting up anchor steel wire rope (7). One end of the anchor steel wire rope (7) is connected to the anchor rod anchored on the rock mass (1), and the other end is connected to the horizontal rod (6) and tensioned to a tension of not less than 5kN.

5. The construction method for an embedded anchored high-altitude reinforced concrete cantilever walkway according to claim 3, characterized in that, After the triangular support frame is erected, the next step is to install monitoring equipment. Monitoring sections are set at intervals along the longitudinal direction of the triangular support frame, and monitoring points are set up at corners, ends and areas of concentrated load. A monitoring point layer is set on the top surface of the foundation, the sweeping rod layer, the middle of the triangular support frame, and the top operating surface to form a three-dimensional grid; Install monitoring equipment at the monitoring points.

6. The construction method for an embedded anchored high-altitude reinforced concrete cantilever walkway according to claim 1, characterized in that, Anchoring and installing cantilever beam components includes: An anchoring groove is opened on the rock mass (1) or the existing concrete matrix. A second set of anchor holes is drilled on the wall of the anchoring groove. The second set of anchor holes includes several main force anchor holes with a depth of not less than 1200 mm, several auxiliary force anchor holes with a depth of not less than 700 mm, and several haunch anchor holes with a depth of not less than 300 mm and an upward drilling direction. Structural anchoring adhesive was injected into the second set of anchor holes, and the second set of anchors (3) were installed. After the anchoring adhesive had initially cured, cement grout was injected into the second set of anchor holes and cured to form a permanent anchor. The anchoring groove also has an inverted conical groove on its wall.

7. The construction method for an embedded anchored high-altitude reinforced concrete cantilever walkway according to claim 6, characterized in that, The drilling direction of the haunched anchor bolt holes makes an angle of 45°±5° with the horizontal plane, and there are 4 haunched anchor bolt holes.

8. The construction method for an embedded anchored high-altitude reinforced concrete cantilever walkway according to claim 6, characterized in that, When the rock mass integrity KV of the rock mass (1) is ≥0.8, the implantation depth of the second set of anchor bolts (3) is configured to be 800mm; When 0.5≤KV<0.8, the implantation depth of the second set of anchor bolts (2) is configured to be 1200mm; When KV<0.5, the second set of anchors (2) is configured with an implantation depth of 1500mm and is connected to a shear key.

9. The construction method for an embedded anchored high-altitude reinforced concrete cantilever walkway according to claim 1, characterized in that, Building a comprehensive support system (11) includes: Solid wood squares are used as uprights and arranged in a matrix on the triangular support frame. The upper and lower ends of the uprights are fixed to the cantilever beam components or formwork support structure and the triangular support frame by iron nails. Along the height direction of the full-span support system (11), several tie bars are set at intervals. One end of the tie bar is anchored to the rock mass (1) or the existing concrete matrix, and the other end is connected to the uprights or horizontal wooden beams of the full-span support system (11).

10. The construction method for an embedded anchored high-altitude reinforced concrete cantilever walkway according to claim 1, characterized in that, It also includes the construction of a safety protection system: angle steel is fixed on the rock mass (1) by expansion bolts, and a safety rope is erected on the angle steel along the extension direction of the walkway. Construction workers wear double-hook safety belts and hang the hooks on the safety rope.

11. The construction method for an embedded anchored high-altitude reinforced concrete cantilever walkway according to claim 1, characterized in that, The poured concrete is C30 grade or higher concrete mixed with micro-expansion agent and waterproofing agent, with an impermeability grade of not less than P6; after the concrete has set, its surface is manually roughened to form a rough texture with a depth of 3.2mm to 6.4mm, and a 2% drainage slope is set.

12. The construction method for an embedded anchored high-altitude reinforced concrete cantilever walkway according to claim 1, characterized in that, Geological exploration includes drilling a 50mm diameter, 2m depth borehole every 5m interval to determine the integrity coefficient of the rock mass (1) KV is not less than 0.5 or the strength of the existing concrete matrix is ​​not less than C30.

13. The construction method for an embedded anchored high-altitude reinforced concrete cantilever walkway according to claim 1, characterized in that, The construction of the cantilever walkway also includes the installation of biomimetic railings: Pre-embedded column reinforcement, permanent and temporary combination: During the stage of binding the slab reinforcement and pouring concrete, the column reinforcement is pre-embedded simultaneously. Frame welding: After the main structure of the walkway is completed, the welding positioning of the crossbars and longitudinal bars of the steel frame is adjusted according to the site environment; Formwork casting, one-piece molding: Install customized formwork and pour concrete to make the railing and walkway structure form an integral load-bearing system; Bionic shaping: The bionic texture of the surface is shaped before the second concrete initial setting; Strength testing and finishing: After the concrete reaches the design strength and passes the test, the entire surface is coated with water-based environmentally friendly paint.

14. A construction structure for an embedded anchored high-altitude reinforced concrete cantilever walkway, formed by the embedded anchored high-altitude reinforced concrete cantilever walkway construction method according to any one of claims 1 to 13, characterized in that, include: A fixed foundation is provided, wherein a first set of anchor holes and a second set of anchor holes are provided on the fixed foundation, the first set of anchor holes includes a first inclined anchor hole, and the second set of anchor holes includes a second set of inclined anchor holes; The first set of anchor bolts (2) are anchored in the first set of anchor bolt holes; The second set of anchor bolts (3) are anchored in the second set of anchor bolt holes; A triangular support frame, which is connected to the first set of anchor rods (2); The cantilever beam component is arranged vertically at intervals with the triangular support frame, and the cantilever beam component is connected to the second set of anchor rods (3) by fasteners; A full-span support system (11) is anchored to the fixed foundation and located between the cantilever beam member and the triangular support frame to provide support for the upper cantilever beam member.

Images