A construction method for a road cut high slope protection system

Abstract

This invention discloses a construction method for a high slope protection system in road cuts. During the construction of the active protection net, steel rope anchors with loops are first installed. Then, transition fittings are used to pre-connect the stitching ropes to the longitudinal or transverse support ropes. The transition fittings on the same side of adjacent steel rope nets are interlocked, forming an axially continuous rope passage for the longitudinal or transverse support ropes to pass through, thus connecting the steel rope nets at corresponding positions. This achieves rapid installation and connection of the steel rope nets with the longitudinal and transverse support ropes. After the transverse and longitudinal support ropes are pulled into place, the transition fittings are removed, resulting in a force transfer and completing the layout of the active protection net. This significantly improves the construction efficiency of the active slope protection system, reduces the labor intensity of repeatedly stitching each steel rope net individually on the slope surface, and enhances construction safety.

Description

Technical Field

[0001] This invention relates to the field of slope protection construction technology. More specifically, this invention relates to a construction method for a high cut slope protection system. Background Technology

[0002] High slopes in road cuts refer to the process of excavating a road cut to a certain depth in the ground to meet traffic demands and terrain requirements during road construction, and forming high slopes on both sides of the road cut. To ensure the safety and stability of the road cut structure, it is necessary to construct high slopes on both sides of the cut for support. Adaptive protection systems should be set up and maintained according to different slope heights and gradients. Active protection net systems use flexible steel rope netting to protect sections of the cut slope with dense joints or steep outer slopes prone to rockfalls and landslides. These systems prevent rockfalls and flying stones, and are characterized by their proactivity, reliability, and wide applicability. Compared with traditional slope protection measures, they are more economical, environmentally friendly, and sustainable. However, existing protection netting systems generally involve first placing anchor bolts, then inserting support ropes, and finally sewing the steel rope netting onto the support ropes to complete the protection of the entire slope. The construction process is very cumbersome and inconvenient, requiring construction workers to climb and stay on the slope for extended periods, affecting construction safety. Anchor bolt frame beams, on the other hand, are suitable for rock sections with overall slope stability, fractured rock mass, and small-scale wedge-shaped fractures. The construction of anchor bolt frame beams requires high slope flatness, and construction efficiency needs improvement. Summary of the Invention

[0003] One object of the present invention is to solve at least the above-mentioned problems and to provide at least the advantages that will be described later.

[0004] Another objective of this invention is to provide a construction method for a high slope protection system for road cuts, in order to solve the technical problems of high difficulty and low efficiency in the construction of active protection net structures in the prior art.

[0005] To achieve these objectives and other advantages according to the present invention, a construction method for a high cut slope protection system is provided, comprising the following steps:

[0006] S1. After clearing the slope surface, measure the topographic data of the high slope of the road cut to determine the slope level, grade height and slope. For one side slope, from top to bottom, adopt the active protection net + anchor frame beam protection form.

[0007] S2. Construction of steel rope anchors. The head of the steel rope anchor is equipped with a ring. First, lay out the anchor spacing according to the design drawings, accurately locate the position of the steel rope anchor, drill the anchor hole and clean the hole. The drilling axis is perpendicular to the slope. Grout after installing the steel rope anchor.

[0008] S3. Set up longitudinal support ropes, transverse support ropes, stitching ropes, grid mesh, steel rope mesh, and rope buckles. A rectangular area enclosed by four adjacent steel rope anchors as the top corners is a layout unit. The size of the grid mesh is smaller than the size of the steel rope mesh, which is smaller than the size of the layout unit. The stitching ropes are equipped with rope buckles at both ends for connecting to the loops of the steel rope anchors. The stitching ropes are used to thread the steel rope mesh to the longitudinal support ropes or transverse support ropes on the corresponding side. Positioning marks are set on the longitudinal support ropes and transverse support ropes at intervals according to the corresponding direction of the layout unit. The grid mesh is connected to the longitudinal support ropes, transverse support ropes, and steel rope mesh through connectors.

[0009] S4. A steel rope mesh and a grid mesh are pre-set. A transition pipe is set on each of the four sides of the steel rope mesh. The transition pipe includes a connecting rod. C-shaped rings are connected at equal intervals along the length direction on one side of the connecting rod. The interval distance is not less than the thickness of the C-shaped ring. The axial direction of the C-shaped ring is parallel to the length direction of the connecting rod. The opening of the C-shaped ring is located on the side opposite to the connecting rod, and the opening size of the C-shaped ring is larger than the outer diameter of the longitudinal support rope and the transverse support rope. Pressure rods are detachably connected on both sides of the C-shaped ring on the connecting rod. Locking buckles are also set on both ends of the connecting rod corresponding to the pressure rods to lock the pressure rods. The sewing rope passes through one edge mesh hole and one C-shaped ring of the steel rope mesh in sequence along the side extension direction of the steel rope mesh. The sewing rope wrapped around the C-shaped ring is pressed tightly to the corresponding side of the connecting rod by the pressure rod and locked by the locking buckle.

[0010] S5. Align the transition pipes on the same side of the adjacent steel rope mesh and insert them at intervals. The inner sides of all C-shaped rings will form a rope passage. Take a connecting rope to temporarily tie the two inserted transition pipes together. For the grid mesh, pre-connect the side of the grid mesh to be connected to the outer periphery of the corresponding transition pipe or the steel rope mesh through the connector, and then form a protective net covering all the arrangement units in a section of the area.

[0011] S6. Pass each horizontal support rope through a loop and a rope passage of the same horizontal design in sequence along its length, straighten it, and secure both ends of the horizontal support rope. Remove the horizontal transition fitting, and let the C-shaped ring leave the horizontal support rope through the opening. Pull the longitudinal support rope and pass it through a loop and a rope passage of the same longitudinal design in sequence from top to bottom. Straighten it, secure both ends of the longitudinal support rope, remove the longitudinal transition fitting, and let the C-shaped ring leave the longitudinal support rope through the opening to complete the construction of the active protection net.

[0012] S7. Construction anchor frame beam protection structure.

[0013] Preferably, the pressure bar has pressure grooves spaced apart along its length on the side facing the connecting rod, with each pressure groove corresponding to a C-shaped ring and extending through the connecting rod at the same height, for accommodating and limiting the sewing cord that passes around the corresponding C-shaped ring.

[0014] Preferably, the outer end of the C-ring with the opening and the side of the C-ring fixed by the connecting rod are set as parallel end faces. The spacing between adjacent C-rings on the transition tube is less than the sum of the thickness of the C-ring and the outer diameter of the suture cord, so as to limit the loop of the suture cord to the outside of the corresponding C-ring.

[0015] Preferably, the planar size of the arrangement unit is (4.5m±0.3m)×(4.5m±0.3m).

[0016] Preferably, in step S2, after accurately locating the position of the steel rope anchor, before digging the anchor pit, a recess with a depth not less than the exposed length of the ring is chiseled out at each hole and marked. The hole depth when drilling the anchor hole is greater than 5cm of the length of the steel rope anchor, and the length of the row of anchor holes at the upper edge is greater than the length of the anchor holes at the other height.

[0017] Preferably, adjacent grid meshes are connected with an overlap width of not less than 5 cm.

[0018] Preferably, the specific construction steps of the anchor frame beam are as follows:

[0019] A1. For anchor bolt construction, first mark the anchor bolt hole positions, then drill and clean the holes, fabricate and install the anchor bolts, and grout the anchor holes.

[0020] A2. The positions of the horizontal and vertical beams of the frame beam are laid out using the string line method. For soil slopes, the foundation trench is excavated manually, and for rock slopes, the foundation trench is excavated using a pneumatic pick. The excavation sequence for the same level of slope is from top to bottom, in one step. The bottom of the trench is compacted and smooth, without disturbing the original soil, ensuring that the frame is embedded 30cm into the slope soil and rock and exposed 10cm. If the rock mass is a rocky slope, the frame is embedded 10cm into the slope surface and exposed 30cm.

[0021] A3. Reinforcing bars shall be tied and welded on the slope on site. The net protective layer thickness of the reinforcing bars shall be 50mm. Single-sided welding shall be used when welding the reinforcing bars. The welding length of the single-sided welding shall not be less than 10 times the diameter of the reinforcing bar. The hook of the anchor rod shall be welded to the main reinforcement of the frame beam. The main reinforcement shall be bent up by 10cm. The bottom of the frame shall be anchored to the slope by anchor nails. The anchoring depth shall not be less than 0.5m. The number of joints of reinforcing bars in the same section shall not exceed 1 / 2 of the total number of reinforcing bars.

[0022] A4. Lightweight steel formwork or plastic steel formwork is used for frame beams. The formwork should have a smooth surface and good hardness. Release agent should be applied in advance for use. The formwork is installed using the "line method" and erected according to the line to ensure that the formwork is horizontal and vertical. The side formwork is erected in one go and the two side formworks are relatively fixed. The gap between the formwork and the edge is sealed with mortar to prevent mortar leakage from affecting the quality of concrete.

[0023] A5. Pour concrete for the frame beams. Set a 2cm wide expansion joint every 15m along the frame. Install anchor bolts on both sides and fill the joint with asphalt hemp fiber.

[0024] A6. After the concrete has initially set, cover it with geotextile and spray it with water for curing. The curing time shall not be less than 7 days.

[0025] The present invention has at least the following beneficial effects: The construction method of the high slope protection system of the present invention, during the construction of the active protection net, firstly constructs steel rope anchors with loops, then uses transition fittings to pre-connect the stitching ropes with the longitudinal or transverse support ropes. The transition fittings on the same side of adjacent steel rope nets are interlocked, forming an axially continuous rope passage for the longitudinal or transverse support ropes to pass through, thus connecting the steel rope nets at corresponding positions. This achieves rapid installation and connection of the steel rope nets with the longitudinal and transverse support ropes. After the transverse and longitudinal support ropes are pulled into place, the transition fittings are removed, resulting in a force conversion and completing the layout and construction of the active protection net. This significantly improves the construction efficiency of the active slope protection system, reduces the labor intensity of construction personnel repeatedly stitching each steel rope net individually on the slope surface, and improves construction safety.

[0026] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0027] Figure 1 This is a front view of the transition pipe fitting of the present invention;

[0028] Figure 2 This is a top view of the transition pipe fitting of the present invention;

[0029] Figure 3 This is a front view of the transition tube of the present invention with the stitching rope wound around it;

[0030] Figure 4 This is a front view of the structure of two adjacent transition pipes on the same side of the present invention when they are inserted after being wrapped with a stitching rope;

[0031] Figure 5 For the present invention Figure 4 Top view of the structure;

[0032] Figure 6 This is a schematic diagram of the structure of the active protection netting of the present invention on the slope surface after the construction is completed;

[0033] The following are the reference numerals in the instruction manual: 1. Ring, 2. Longitudinal support rope, 3. Transverse support rope, 4. Sewing rope, 5. Steel rope net, 6. Connecting rod, 7. C-ring, 8. Opening, 9. Pressure rod, 10. Locking buckle, 11. Edge mesh, 12. Rope passage, 13. Pressure groove. Detailed Implementation

[0034] The present invention will now be described in further detail with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description.

[0035] It should be noted that, unless otherwise specified, the experimental methods described in the following embodiments are all conventional methods, and the reagents and materials described are all commercially available unless otherwise specified. In the description of this invention, the terms "lateral", "longitudinal", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0036] like Figure 1-6 As shown, the present invention provides a construction method for a high slope protection system for road cuts, comprising the following steps:

[0037] S1. After clearing the slope surface, measure the topographic data of the high slope of the road cut to determine the slope level, grade height and slope. For one side slope, from top to bottom, adopt the active protection net + anchor frame beam protection form.

[0038] S2. Construction of steel rope anchors. The head of the steel rope anchor is equipped with a ring 1. First, lay out the anchor spacing according to the design drawings, accurately locate the position of the steel rope anchor, drill the anchor hole and clean the hole. The drilling axis is perpendicular to the slope. Grout after installing the steel rope anchor.

[0039] S3. Set up longitudinal support rope 2, transverse support rope 3, stitching rope 4, grid mesh, steel rope mesh 5, and rope buckles. A rectangular area enclosed by four adjacent steel rope anchors as the top corners is a layout unit. The size of the grid mesh is smaller than the size of the steel rope mesh 5, which is smaller than the size of the layout unit. The stitching rope 4 is equipped with rope buckles at both ends for connecting with the loop 1 of the steel rope anchor. The stitching rope 4 is used to thread the steel rope mesh 5 through the longitudinal support rope 2 or transverse support rope 3 on the corresponding side. The longitudinal support rope 2 and transverse support rope 3 are set with positioning marks at intervals according to the corresponding direction of the layout unit. The grid mesh is connected to the longitudinal support rope 2, transverse support rope 3, and steel rope mesh 5 through connectors.

[0040] S4. A steel rope mesh 5 and a grid mesh are pre-set. A transition pipe is set on each of the four sides of the steel rope mesh 5. The transition pipe includes a connecting rod 6. C-shaped rings 7 are connected at equal intervals along the length direction on one side of the connecting rod 6. The interval distance is not less than the thickness of the C-shaped ring 7. The axial direction of the C-shaped ring 7 is parallel to the length direction of the connecting rod 6. The opening 8 of the C-shaped ring 7 is located on the side opposite to the connecting rod 6, and the size of the opening 8 of the C-shaped ring 7 is larger than the outer diameter of the longitudinal support rope 2 and the transverse support rope 3. Pressure rods 9 are detachably connected to both sides of the C-shaped ring 7 on the connecting rod 6. Locking buckles 10 are also set on both ends of the connecting rod 6 corresponding to the pressure rods 9 to lock the pressure rods 9. The sewing rope 4 passes through one edge mesh hole 11 and one C-shaped ring 7 of the steel rope mesh 5 in sequence along the side extension direction of the steel rope mesh 5. The sewing rope 4 wrapped with the C-shaped ring 7 is pressed tightly to the corresponding side of the connecting rod 6 by the pressure rods 9 and locked by the locking buckles 10.

[0041] S5. Align the transition pipes on the same side of the adjacent steel rope mesh 5 and insert them at intervals. The inner sides of all C-shaped rings 7 together form a rope passage 12. Take a connecting rope to temporarily tie the two inserted transition pipes together. For the grid mesh, pre-connect the side of the grid mesh to be connected to the outer periphery of the corresponding transition pipe or the steel rope mesh 5 through the connector, and form a protective net covering all the arrangement units in a section area in sequence.

[0042] S6. Pass each transverse support rope 3 through a loop 1 and a rope passage 12 of the same transverse design in sequence along its length, straighten it, and secure both ends of the transverse support rope 3. Remove the transverse transition fitting, and the C-shaped ring 7 leaves the transverse support rope 3 through the opening 8. Pull the longitudinal support rope 2 and pass it through a loop 1 and a rope passage 12 of the same longitudinal design in sequence from top to bottom. Straighten it, secure both ends of the longitudinal support rope 2, remove the longitudinal transition fitting, and the C-shaped ring 7 leaves the longitudinal support rope 2 through the opening 8 to complete the construction of the active protection net.

[0043] S7. Construction anchor frame beam protection structure.

[0044] The sewing rope 4 primarily serves a connecting function. Before the top loop 1 of the steel rope anchor rod, which is anchored on a section of the slope along the transverse region by the longitudinal support rope 2 and the transverse support rope 3, a transition tube is set on each of the four sides of the steel rope net 5. The sewing rope 4 is used to crisscross and sequentially wrap around the steel rope net 5 along its side extension direction, passing through a mesh hole and then around the first C-shaped loop 7 at the edge. After passing through the next mesh hole, it wraps around the second C-shaped loop 7, and so on, until it wraps around all the C-shaped loops 7 on the current transition tube. The two ends of the sewing rope 4 are temporarily locked to the steel rope net 5 with rope buckles to ensure that the sewing rope 4 is not loose when wrapped around the transition tube. The length of the transition tube and the spacing of the C-shaped loops 7 are designed according to the required length range of the wrapping connection. For adjacent steel rope nets 5, after wrapping around the transition tube, the two transition tubes on the corresponding sides are inserted to further precisely limit the position of the sewing rope 4. Temporarily lock the outer side of the component with rope to ensure the insertion state of the two transition pipes. Temporarily connect the adjacent steel rope nets 5 into one unit through the insertion of the transition pipes. The grid net is tied to the corresponding position of the steel rope net 5 and transition pipe with connecting parts such as sewing rope 4 or iron wire as needed. Then, the transverse support rope 3 and the longitudinal support rope 2 pass through the rope passage 12 formed in the middle of the transition pipe and the ring 1 at the top of the steel rope anchor. First pull the transverse support rope 3, and then use gravity and slope advantage to pull the longitudinal support rope 2. According to the positioning mark or set the positioning ring (to ensure that it can pass smoothly through each ring 1 and rope passage 12), pass through each rope passage 12 and ring 1 of the same design transverse or longitudinal direction in sequence to realize the quick installation and connection of the steel rope net 5 with the longitudinal support rope 2 and the transverse support rope 3. Then remove the transition pipe and transfer the force of the sewing rope 4 to the inner longitudinal support rope 2 or transverse support rope 3 for pretensioning.

[0045] By setting transition pipes during the construction of the active protection net, and splicing two transition pipes on opposite sides, the steel rope nets 5 on adjacent sides can be quickly connected. Rope passages 12 are formed in the two spliced ​​transition pipes, enabling rapid connection between the longitudinal support ropes 2 and the transverse support ropes 3 and the steel rope nets 5. The transverse support ropes 3 are pulled first, followed by the longitudinal support ropes 2, reducing the difficulty of threading the ropes. After the transverse support ropes 3 and the longitudinal support ropes 2 are pulled into place, the transition pipes are removed, forming a force conversion and completing the layout and construction of the active protection net. This significantly improves the construction efficiency of the slope active protection system, reduces the labor intensity of construction personnel repeatedly sewing each steel rope net 5 individually on the slope surface, and improves construction safety.

[0046] In another technical solution, such as Figure 1-5As shown, the side of the pressure rod 9 facing the connecting rod 6 is provided with pressure grooves 13 spaced apart along its length. Each pressure groove 13 corresponds to a C-shaped ring 7 and is formed through the connecting rod 6 at the same height, serving to accommodate and limit the suture rope 4 that passes around the corresponding C-shaped ring 7. By providing pressure grooves 13, when the pressure rod 9 temporarily presses and locks the position of the suture rope 4, it is beneficial to further improve the limiting effect on the suture rope 4 and prevent the suture rope 4 from slipping and disturbing.

[0047] In another technical solution, such as Figure 1-5 As shown, the outer end of the C-shaped ring 7 with the opening 8 is parallel to the end face of the side of the connecting rod 6 that fixes the C-shaped ring 7. The spacing between adjacent C-shaped rings 7 on the transition pipe is less than the sum of the thickness of the C-shaped ring 7 and the outer diameter of the suture rope 4, so as to limit the loop of the suture rope 4 to the outside of the corresponding C-shaped ring 7. Arranging the side of the C-shaped ring 7 with the opening 8 as a plane can reduce the radial width after the two transition pipes are spliced, avoid affecting the structure of the adjacent suture rope 4 and steel wire mesh 5, and make the size smaller for easier installation and removal. At the same time, it increases the contact surface, which is beneficial for pressing and limiting the suture rope 4.

[0048] In another technical solution, such as Figure 6 As shown, the planar size of the arrangement unit is (4.5m ± 0.3m) × (4.5m ± 0.3m). The corresponding steel rope mesh 5 is generally set to 4m × 4m, and a SO / 2.2 / 50 type grid mesh with small mesh size is laid under the steel rope mesh 5 to prevent the collapse of small-sized rock blocks.

[0049] In another technical solution, such as Figure 6 As shown, in step S2, after accurately locating the steel rope anchor, before digging the anchor pit, a recess with a depth not less than the exposed length of the ring 1 is chiseled out at each hole position, so that the subsequent longitudinal support rope 2 and transverse support rope 3 can pass through the ring 1 and be marked. The hole depth when drilling the anchor hole is more than 5cm greater than the length of the steel rope anchor, and the length of the row of anchor holes at the upper edge is greater than the length of the anchor holes at the other height, thereby improving the stability of the steel rope anchor anchored on the slope.

[0050] In another technical solution, adjacent grid meshes are connected with an overlap width of not less than 5cm to ensure the connection strength between the grid meshes.

[0051] In another technical solution, the specific construction steps of the anchor frame beam are as follows:

[0052] A1. Construction of anchor bolts: First, mark the anchor bolt hole positions, then drill and clean the holes, fabricate and install the anchor bolts, and grout the anchor holes. The anchor bolts are designed as fully bonded anchor bolts, HRB400 Φ32mm, 6-12m in length (see the cross-sectional diagram of the deep cut in this section for specific lengths), with a hole diameter of 90mm and an anchoring angle of 15-25°.

[0053] When marking out the anchor bolt hole positions, paint should be used to mark the hole positions on the rock surface. The anchor bolt holes should be drilled from top to bottom using a pneumatic down-the-hole drill. The diameter and depth of the anchor bolt holes should not be less than the design values. The holes should be perpendicular to the slope surface with an inclination angle of 2°. The drill should be lifted onto the platform using a tripod. The drill should be accurately installed and fixed according to the hole positions marked out on the slope surface, and the machine position should be strictly and carefully adjusted to ensure that the deviation of the anchor hole drilling position does not exceed 50mm.

[0054] After the anchor bolt hole reaches the designed depth, drilling should not be stopped immediately. Drilling should be maintained steady for 1-2 minutes to prevent the bottom of the hole from failing to reach the designed diameter. During drilling, drilling parameters and speed should be carefully controlled to prevent various accidents such as drill bit burial or jamming. If pressurized water flows out of the anchor hole, the anchor bolt and grouting can only be installed after the water pressure and volume have decreased. If necessary, drainage holes should be installed in appropriate locations around the anchor bolt hole.

[0055] Before anchor bolt fabrication, the anchor bolt strength, elastic modulus, and cross-sectional area should be randomly inspected according to specifications. Unqualified products are strictly prohibited from use. Before installation, check the anchor bolt for straightness. Positioning should be slow and steady. When inserting the anchor bolt, the grouting pipe should be simultaneously placed to the bottom of the borehole. The anchor bolt anchoring section should be bent at 90° and tied to the main reinforcement. End bending can only be carried out when the cement mortar strength reaches 80% or higher.

[0056] The cement mortar strength should be ≥30MPa. It should be made with fresh silicate cement of grade 425 or higher, produced within the last 3 months. The bleeding rate after mixing should be controlled at 2%, with a maximum of 3%. The cement mortar must be mixed strictly according to the design mix ratio. The mortar should be mixed evenly until the specified consistency is reached, and then slowly stirred until the grouting is completed.

[0057] The specific procedure is to add water first, then cement, and finally sand. After all materials are added, mix them thoroughly within the specified time. Use a high-speed rotary mixer with a speed of 1500-2000 rpm, and mix for approximately 2 minutes. Then store the mixture in a slow-moving storage tank. Once the planned amount of grout has been stored, begin grouting. Each hole should be filled completely without leakage; do not pour in sections to prevent air bubbles from seeping into the grout.

[0058] During the grouting process, air and water inside the hole must be strictly removed without affecting the grouting quality or the bonding force between the anchor body and the hole wall. The method of bottom grouting, grout return at the hole opening, and secondary grouting is adopted.

[0059] The grout volume for anchor holes is generally 120%-130% of the designed grout volume. However, if there are cracks, cavities, or fissures, the grout volume will be significantly overfilled. Therefore, careful attention must be paid to this before grout preparation and during the grouting process.

[0060] Grouting pressure: To ensure the bearing capacity of the anchor bolts, the minimum grouting pressure should be 0.2-0.6 MPa.

[0061] A2. The positions of the horizontal and vertical beams of the frame beam are laid out using the string line method. For soil slopes, the foundation trench is excavated manually, and for rock slopes, the foundation trench is excavated using a pneumatic pick. The excavation sequence for the same level of slope is from top to bottom, in one step. The bottom of the trench is compacted and smooth, without disturbing the original soil, ensuring that the frame is embedded 30cm into the slope rock and soil and exposed 10cm. If the rock mass is a rocky slope, the frame is embedded 10cm into the slope surface and exposed 30cm.

[0062] A3. Reinforcing bars are tied and welded on-site on the slope. The net protective layer thickness of the reinforcing bars is 50mm. Single-sided welding is used when welding the reinforcing bars, and the welding length on one side shall not be less than 10 times the diameter of the reinforcing bar. The hooks of the anchor rods must be firmly welded to the main reinforcement of the frame beam. If the anchor rods and stirrups interfere with each other, the stirrups can be adjusted appropriately. Attention should be paid to reserving the location of expansion joints when tying and welding the reinforcing bars. At the end points of the frame beams and vertical beams and at the expansion joints, the main reinforcement bars are bent up by 10cm. To prevent the frame from shifting and sagging during construction, the bottom of the frame is anchored to the slope by Φ6 anchors with an anchoring depth of not less than 0.5m. The welded joints of the reinforcing bars must be staggered and dispersed. The number of joints of the reinforcing bars in the same section shall not exceed 1 / 2 of the total number of reinforcing bars.

[0063] A4. Lightweight steel or PVC formwork is used for the frame beams. The formwork must have a smooth surface and good hardness, and a release agent should be applied in advance. The formwork is installed using the "line method," erecting it according to the line to ensure that the formwork is horizontal and vertical. The side formwork is erected in one go, and the two side formworks are fixed relative to each other. The gaps between the formwork and the surface are sealed with mortar to prevent mortar leakage from affecting the quality of the concrete.

[0064] A5. Concrete Pouring: Concrete is centrally mixed according to a C30 mix ratio and transported horizontally by concrete mixer trucks. A boom pump is used for pouring, proceeding from bottom to top. To ensure pouring speed, multiple points can be poured simultaneously. Concrete is vibrated while pouring using an immersion vibrator. Pay attention to the vibration at the corners and the vibration time to ensure density. The frame beams have small cross-sections and dense reinforcement, especially at the intersections of horizontal and vertical beams; ensure thorough vibration. After completion, the top surface is smoothed with a trowel. An expansion joint, 2cm wide, is installed every 15m along the frame, with anchor bolts on both sides and filled with asphalt-impregnated hemp fiber.

[0065] A6. Concrete curing: Immediately after the concrete has initially set, cover it with geotextile and spray water for curing. Keep it moist by spraying water at certain intervals, and the curing time shall not be less than 7 days.

[0066] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A construction method for a high slope protection system for road cuts, characterized in that, Includes the following steps: S1. After clearing the slope surface, measure the topographic data of the high slope of the road cut to determine the slope level, grade height and slope. For one side slope, from top to bottom, adopt the active protection net + anchor frame beam protection form. S2. Construction of steel rope anchors. The head of the steel rope anchor is equipped with a ring. First, lay out the anchor spacing according to the design drawings, accurately locate the position of the steel rope anchor, drill the anchor hole and clean the hole. The drilling axis is perpendicular to the slope. Grout after installing the steel rope anchor. S3. Set up longitudinal support ropes, transverse support ropes, stitching ropes, grid mesh, steel rope mesh, and rope buckles. A rectangular area enclosed by four adjacent steel rope anchors as the top corners is a layout unit. The size of the grid mesh is smaller than the size of the steel rope mesh, which is smaller than the size of the layout unit. The stitching ropes are equipped with rope buckles at both ends for connecting to the loops of the steel rope anchors. The stitching ropes are used to thread the steel rope mesh to the longitudinal support ropes or transverse support ropes on the corresponding side. Positioning marks are set on the longitudinal support ropes and transverse support ropes at intervals according to the corresponding direction of the layout unit. The grid mesh is connected to the longitudinal support ropes, transverse support ropes, and steel rope mesh through connectors. S4. A steel rope mesh and a grid mesh are pre-set. A transition pipe is set on each of the four sides of the steel rope mesh. The transition pipe includes a connecting rod. C-shaped rings are connected at equal intervals along the length direction on one side of the connecting rod. The interval distance is not less than the thickness of the C-shaped ring. The axial direction of the C-shaped ring is parallel to the length direction of the connecting rod. The opening of the C-shaped ring is located on the side opposite to the connecting rod, and the opening size of the C-shaped ring is larger than the outer diameter of the longitudinal support rope and the transverse support rope. Pressure rods are detachably connected on both sides of the C-shaped ring on the connecting rod. Locking buckles are also set on both ends of the connecting rod corresponding to the pressure rods to lock the pressure rods. The sewing rope passes through one edge mesh hole and one C-shaped ring of the steel rope mesh in sequence along the side extension direction of the steel rope mesh. The sewing rope wrapped around the C-shaped ring is pressed tightly to the corresponding side of the connecting rod by the pressure rod and locked by the locking buckle. S5. Align the transition pipes on the same side of the adjacent steel rope mesh and insert them at intervals. The inner sides of all C-shaped rings will form a rope passage. Take a connecting rope to temporarily tie the two inserted transition pipes together. For the grid mesh, pre-connect the side of the grid mesh to be connected to the outer periphery of the corresponding transition pipe or the steel rope mesh through the connector, and then form a protective net covering all the arrangement units in a section of the area. S6. Pass each horizontal support rope through a loop and a rope passage of the same horizontal design in sequence along its length, straighten it, and secure both ends of the horizontal support rope. Remove the horizontal transition fitting, and let the C-shaped ring leave the horizontal support rope through the opening. Pull the longitudinal support rope and pass it through a loop and a rope passage of the same longitudinal design in sequence from top to bottom. Straighten it, secure both ends of the longitudinal support rope, remove the longitudinal transition fitting, and let the C-shaped ring leave the longitudinal support rope through the opening to complete the construction of the active protection net. S7. Construction anchor frame beam protection structure.

2. The construction method of the high slope protection system for road cuts as described in claim 1, characterized in that, The pressure bar has pressure grooves spaced apart along its length on the side facing the connecting rod. Each pressure groove corresponds to a C-shaped ring and is formed through the connecting rod at the same height to accommodate and limit the sewing cord that passes around the corresponding C-shaped ring.

3. The construction method of the high slope protection system for road cuts as described in claim 1, characterized in that, The planar dimensions of the arrangement unit are (4.5m ± 0.3m) × (4.5m ± 0.3m).

4. The construction method of the high slope protection system for road cuts as described in claim 1, characterized in that, In step S2, after accurately locating the steel rope anchor, before digging the anchor pit, a recess with a depth not less than the exposed length of the ring is chiseled out at each hole and marked. The hole depth when drilling the anchor hole is greater than 5cm of the length of the steel rope anchor, and the length of the row of anchor holes at the upper edge is greater than the length of the anchor holes at the other height.

5. The construction method of the high slope protection system for road cuts as described in claim 1, characterized in that, The adjacent grid meshes are connected and the overlap width is not less than 5cm.

6. The construction method of the high slope protection system for road cuts as described in claim 1, characterized in that, The specific construction steps for the anchor frame beam are as follows: A1. For anchor bolt construction, first mark the anchor bolt hole positions, then drill and clean the holes, fabricate and install the anchor bolts, and grout the anchor holes. A2. The positions of the horizontal and vertical beams of the frame beam are laid out using the string line method. For soil slopes, the foundation trench is excavated manually, and for rock slopes, the foundation trench is excavated using a pneumatic pick. The excavation sequence for the same level of slope is from top to bottom, in one step. The bottom of the trench is compacted and smooth, without disturbing the original soil, ensuring that the frame is embedded 30cm into the slope soil and rock and exposed 10cm. If the rock mass is a rocky slope, the frame is embedded 10cm into the slope surface and exposed 30cm. A3. Reinforcing bars shall be tied and welded on the slope on site. The net protective layer thickness of the reinforcing bars shall be 50mm. Single-sided welding shall be used when welding the reinforcing bars. The welding length of the single-sided welding shall not be less than 10 times the diameter of the reinforcing bar. The hook of the anchor rod shall be welded to the main reinforcement of the frame beam. The main reinforcement shall be bent up by 10cm. The bottom of the frame shall be anchored to the slope by anchor nails. The anchoring depth shall not be less than 0.5m. The number of joints of reinforcing bars in the same section shall not exceed 1 / 2 of the total number of reinforcing bars. A4. Lightweight steel formwork or plastic steel formwork is used for frame beams. The formwork should have a smooth surface and good hardness. Release agent should be applied in advance for use. The formwork is installed by stringing a line to ensure that the formwork is horizontal and vertical. The side formwork is erected in one go and the two side formworks are fixed to each other. The gap between the formwork and the edge is sealed with mortar to prevent mortar leakage from affecting the quality of concrete. A5. Pour concrete for the frame beams. Set a 2cm wide expansion joint every 15m along the frame. Install anchor bolts on both sides and fill the joint with asphalt hemp fiber. A6. After the concrete has initially set, cover it with geotextile and spray it with water for curing. The curing time shall not be less than 7 days.

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