Prestressed anchor cable sawtooth frame beam and construction method thereof

Abstract

This invention discloses a prestressed anchor cable sawtooth frame beam and its construction method, relating to the field of slope reinforcement technology in geotechnical engineering. The frame beam includes a crossbeam, a longitudinal beam, prestressed anchor cables, and multiple triangular force-bearing blocks arranged along the longitudinal beam. These triangular force-bearing blocks form a sawtooth-shaped stress surface, with the normal direction of the sawtooth-shaped stress surface being substantially parallel to the slope's downward direction. The anchor cables pass through the top of the teeth and are anchored to stable rock layers. An enlarged foundation is provided at the lower end of the longitudinal beam, embedded in the slope and with anti-slip steps at its base. During construction, a sawtooth groove is excavated on the undisturbed slope. After reinforcing steel is tied, the force-bearing blocks, longitudinal beam, and enlarged foundation are integrally cast, and the anchor cables are tensioned and locked. This invention decomposes and transforms the oblique thrust, reducing the slope's downward tendency. The enlarged foundation provides upward support to prevent subsidence. Prestress transfer is efficient, and the construction is tightly integrated, which helps improve the stress state of the frame beam, reduces the risk of frame subsidence and separation from the slope, and enhances the slope treatment effect.

Description

Technical Field

[0001] This invention relates to the field of slope reinforcement technology in geotechnical engineering, and in particular to a prestressed anchor cable sawtooth frame beam and its construction method. Background Technology

[0002] Prestressed anchor cable frame beams are one of the commonly used and effective means of controlling steep slopes and landslide disasters. They are constructed by anchoring prestressed anchor cables through the potential sliding surface to the stable bedrock and applying prestress to the surface frame beams, thereby increasing the normal stress of the sliding surface and enhancing the anti-sliding capacity of the sliding body.

[0003] However, engineering practice and theoretical research show that the direction of landslide thrust is not horizontal, but rather at a certain angle (usually 10°–30°) to the horizontal plane. This oblique thrust can be decomposed into horizontal and vertical components. In conventional frame beam structures, the longitudinal and transverse beams often have an angle with the sliding surface. The reaction force provided by traditional frame beams is mainly used to increase the normal stress on the sliding surface to enhance frictional resistance, but it fails to effectively utilize the principle of force decomposition to directly reduce the sliding force. This mechanistic deficiency leads to problems such as soil slippage, collapse, frame detachment from the slope, and frame subsidence still occurring at some construction sites after the use of traditional prestressed anchored frame beams. This weakens the interaction between the frame and the soil, affecting the long-term stability of the slope.

[0004] Therefore, it is necessary to improve the structural form and construction method of traditional frame beams to make their stress mechanism more reasonable, so as to more effectively convert the sliding force into a component that is beneficial to the structure, and at the same time enhance the collaborative working ability between the frame and the slope, thereby improving the landslide control effect. Summary of the Invention

[0005] The purpose of this invention is to provide a prestressed anchor cable sawtooth frame beam and its construction method to solve the problems existing in the prior art.

[0006] To achieve the above objectives, the present invention provides a prestressed anchor cable sawtooth frame beam, comprising a crossbeam, a longitudinal beam, anchor cables, and triangular force-bearing blocks; a sawtooth-shaped force-bearing surface is provided on the longitudinal beam, the sawtooth-shaped force-bearing surface is distributed along the height direction of the longitudinal beam, and the sawtooth-shaped force-bearing surface is composed of a plurality of triangular force-bearing blocks arranged sequentially along the height direction of the longitudinal beam, each of the triangular force-bearing blocks having a bearing surface facing upwards towards the slope, the straight line containing the normal of the bearing surface being parallel to the design landslide thrust direction, and the direction of the normal reaction force generated by the bearing surface on the slope being opposite to the design landslide thrust direction; the number of anchor cables is multiple, and some of the triangular force-bearing blocks correspond to the anchor cables; the anchor cables pass through the tooth tip position of the corresponding triangular force-bearing block and are anchored in the stable bedrock of the slope, and the anchor plate of the anchor cable is provided on the tooth tip surface of the triangular force-bearing block.

[0007] Preferably, an enlarged foundation is provided at the lowest triangular force component block. The enlarged foundation extends into the inside of the slope body, and its bottom surface rests on a stable foundation bearing layer. The bottom area of ​​the triangular force component block is smaller than the bottom area of ​​the enlarged foundation.

[0008] Preferably, the bottom surface of the enlarged foundation is lower than the toe line of the slope and is embedded to the designed embedment depth of the slope. The bottom surface of the enlarged foundation is provided with anti-slip steps that slope inward toward the inside of the slope.

[0009] Preferably, when the angle between the designed landslide thrust and the horizontal plane is θ, the angle between each bearing surface and the horizontal plane is determined according to θ, so that the straight line containing the normal of each bearing surface is parallel to the direction of the designed landslide thrust.

[0010] Preferably, both the triangular force-shaping block and the enlarged foundation are reinforced concrete structures and are integrally cast with the longitudinal beam.

[0011] Preferably, the crossbeam and the longitudinal beam constitute an integral frame structure and are embedded at the slope foot design depth, and the sawtooth-shaped force-bearing surface is in a normal relationship with the direction of the downward force.

[0012] This invention also provides a construction method for prestressed anchor cable sawtooth frame beams, comprising the following steps: S1. After the slope is trimmed and measured, clean and trim the slope to be reinforced, and lay out the crossbeams, longitudinal beams, triangular force-shaping blocks, enlarged foundations and anchor cable holes according to the design position. S2. Utilizing the existing topography of the slope, using a combination of manual labor and small machinery, excavate the transverse beam groove and longitudinal beam groove along the layout position, and excavate multiple sequentially connected toothed grooves on the side of the longitudinal beam groove facing the slope according to the design requirements; excavate an enlarged foundation pit at the lowest toothed groove, and form anti-slip steps extending towards the inside of the slope at the base of the enlarged foundation pit. S3. Drill anchor holes at the corresponding positions of the tooth tops of the toothed grooves, extending the anchor holes to the stable rock strata of the slope; install the anchor cables in the anchor holes and grout the anchoring sections of the anchor cables; S4. Bind the crossbeam reinforcement, longitudinal beam reinforcement, triangular force block reinforcement and enlarged foundation reinforcement in the crossbeam groove, longitudinal beam groove, toothed groove and enlarged foundation pit respectively, and connect the crossbeam reinforcement, longitudinal beam reinforcement, triangular force block reinforcement and enlarged foundation reinforcement to form an integral reinforcement skeleton. S5. Install the templates for the crossbeams, longitudinal beams, triangular force-shaping blocks and enlarged foundations, and install anchor plates and anchorage pre-embedded parts at each tooth tip for the anchor cables to pass through; S6. Pour concrete to form a reinforced concrete integral structure of crossbeams, longitudinal beams, triangular force blocks and enlarged foundation, and ensure that the triangular force blocks are in close contact with the slope and cure the poured concrete. S7. After the concrete strength reaches the design requirements, the anchor cable is tensioned in stages, and locked by the anchor after the tension force reaches the design prestress value. S8. Seal the anchorages and exposed anchor cables, and restore and protect the slope of the construction area.

[0013] Preferably, in step S2, the original slope is excavated according to the design contour of the sawtooth bearing surface, so that the sawtooth grooves formed by the excavation are connected in sequence, and the triangular force component blocks formed by casting are in contact with the groove walls of the sawtooth grooves; the enlarged foundation pit is excavated to the design bearing layer, and the bearing conditions of the foundation are checked; and inwardly inclined anti-slip steps are set and excavated simultaneously with the enlarged foundation pit.

[0014] Preferably, the anchor cable passes through the top of the tooth of the triangular force component block and is anchored in the stable bedrock of the slope. The anchor plate of the anchor cable is set at the top of the tooth of the triangular force component block, and the prestress is directly transmitted to the sawtooth-shaped force surface through the tooth top. In step S3, after cleaning the anchor cable hole, the anchor cable and grouting pipe are installed, and grout is injected into the anchor cable hole through the grouting pipe to connect the anchoring section of the anchor cable with the stable rock layer.

[0015] Preferably, in step S6, the longitudinal beam, the triangular force component block and the enlarged foundation are continuously cast and formed. When the casting needs to be done in sections due to construction conditions, a construction joint connection structure is set between adjacent casting sections. In step S7, after the concrete strength reaches a predetermined proportion of the design strength, the anchor cable is prestressed in the order of pre-tensioning, graded tensioning and locking, and the tension force at each stage and the elongation of the anchor cable are recorded.

[0016] Compared with the prior art, the present invention has the following advantages and technical effects: The prestressed anchor cable sawtooth frame beam and its construction method provided by this invention, by setting a sawtooth-shaped stress surface with the straight line of the bearing surface normal being basically parallel to the design landslide thrust direction, causes each bearing surface to generate a normal reaction force on the slope opposite to the landslide thrust direction. The horizontal and vertical components of this normal reaction force resist the horizontal and downward components of the landslide thrust, respectively, which helps to reduce the slope's downward tendency and improve the stress state of the frame beam, effectively avoiding collapse and voiding. The anchor cable passes through the apex of the triangular component block, and the prestress is directly transferred to the sawtooth stress surface through the apex, resulting in the shortest force transmission path and the highest efficiency, avoiding the lag and loss of prestress transmission in traditional arrangements. By setting an enlarged foundation at the lowest component block, reliable upward support is provided, effectively preventing the overall settlement of the frame beam, ensuring long-term close contact between the frame and the slope, and avoiding prestress loss and reinforcement effect attenuation caused by frame settlement. By combining prestressed anchor cable technology, while providing normal stress on the sliding surface, the serrated structure optimizes the stress on the frame itself, fully leveraging the synergistic reinforcement effect of the anchor cables and frame beams. Employing a "topography-first excavation and shaping" construction method, the load-bearing blocks are directly placed on the undisturbed soil (rock), reducing backfill and settlement issues, ensuring a tight fit between the serrated load-bearing surface and the slope, and guaranteeing reliable construction quality. The serrated load-bearing surface and enlarged foundation can be integrally cast with the frame beams; the construction technology is mature, requires no additional complex equipment, and is highly feasible. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention.

[0018] Figure 1 This is a plan view of the prestressed anchor cable sawtooth frame beam of the present invention.

[0019] Figure 2 This is a cross-sectional view of the longitudinal beam in the prestressed anchor cable sawtooth frame beam of the present invention.

[0020] In the diagram: 1. Horizontal beam; 2. Longitudinal beam; 3. Anchor cable; 4. Triangular force component block; 5. Sawtooth force surface; 6. Enlarged foundation; 7. Anti-slip step. Detailed Implementation

[0021] It should be noted that, unless otherwise specified, the embodiments and features described in this invention can be combined with each other. The described embodiments are merely some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this invention. The invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0022] like Figures 1 to 2 As shown, the present invention provides a prestressed anchor cable sawtooth frame beam, including a crossbeam 1, a longitudinal beam 2, anchor cables 3, and triangular force-bearing blocks 4; a sawtooth force-bearing surface 5 is provided on the longitudinal beam 2, the sawtooth force-bearing surface 5 is distributed along the height direction of the longitudinal beam 2, and the sawtooth force-bearing surface 5 is composed of multiple triangular force-bearing blocks 4 arranged sequentially along the height direction of the longitudinal beam 2. Each triangular force-bearing block 4 has a bearing surface facing upwards on the slope, the straight line where the normal of the bearing surface is located is parallel to the direction of the designed landslide thrust, and the direction of the normal reaction force generated by the bearing surface on the slope is opposite to the direction of the designed landslide thrust; there are multiple anchor cables 3, and some of the triangular force-bearing blocks 4 correspond to anchor cables 3 respectively; the anchor cables 3 pass through the tooth top position of the corresponding triangular force-bearing block 4 and are anchored in the stable bedrock of the slope, and the anchor plate of the anchor cable 3 is provided on the tooth top surface of the triangular force-bearing block 4.

[0023] By setting a sawtooth-shaped force-bearing surface 5 composed of multiple continuous triangular force-bearing blocks 4 on the longitudinal beam 2, and making the force-bearing surface of the triangular force-bearing blocks 4 in a normal relationship with the direction of the sliding force of the landslide thrust, when the sliding force acts on the force-bearing surface, a normal reaction force pointing into the slope body and a tangential component force opposite to the direction of the sliding force are generated, thereby directly reducing the effective sliding force, optimizing the traditional passive resistance into active decomposition and transformation, effectively reducing the sliding force, and improving the stress state of the soil behind the frame from the source, avoiding collapse and voiding diseases.

[0024] To further optimize the design, an enlarged foundation 6 is installed at the bottom triangular force component block 4. The enlarged foundation 6 extends into the inside of the slope, and its bottom surface rests on a stable foundation bearing layer. The bottom area of ​​the triangular force component block 4 is smaller than the bottom area of ​​the enlarged foundation 6.

[0025] By setting an enlarged foundation 6 at the bottom triangular force component block 4, the bottom surface of the enlarged foundation 6 is placed on a stable foundation bearing layer and the bottom area is larger than the bottom area of ​​the triangular force component block 4. This allows it to provide an upward supporting reaction force on the basis of exerting the force component, effectively controlling the vertical displacement of the frame and preventing structural instability caused by uneven settlement.

[0026] Further optimize the plan by increasing the bottom elevation of foundation 6 to be lower than the slope toe line and embedding it into the slope design embedment depth, and by adding anti-slip steps 7 that slope inwards towards the inside of the slope to the bottom of foundation 6.

[0027] By setting the bottom elevation of the enlarged foundation 6 below the toe line of the slope and embedding it into the slope to a certain depth, and by setting the bottom surface with anti-slip steps 7 that slope inward toward the inside of the slope, the anti-slip and load-bearing capacity of the enlarged foundation 6 can be enhanced, ensuring a stable connection between the enlarged foundation 6 and the slope.

[0028] To further optimize the scheme, when the angle between the designed landslide thrust and the horizontal plane is θ, the angle between each bearing surface and the horizontal plane is determined according to θ, so that the straight line containing the normal of each bearing surface is parallel to the direction of the designed landslide thrust.

[0029] By determining the inclination angle of the bearing surface based on the design landslide thrust direction, the straight line containing the normal of the bearing surface is made basically parallel to the design landslide thrust direction, thus enabling the normal reaction force generated by the bearing surface to effectively resist the landslide thrust. For different slopes, sliding surface morphologies, and thrust directions, the tooth angle of the triangular force components can be adjusted accordingly to improve the adaptability of the sawtooth frame beam to different slope conditions.

[0030] The scheme was further optimized so that both the triangular force-shaping block 4 and the enlarged foundation 6 are reinforced concrete structures, and are integrally cast with the longitudinal beam 2.

[0031] By setting the triangular force-shaping block 4 and the enlarged foundation 6 as reinforced concrete structures and casting them integrally with the longitudinal beam 2, the structural integrity and effective force transmission between the components can be ensured, avoiding stress concentration and structural damage caused by weak connection nodes.

[0032] Further optimization of the scheme: the crossbeam 1 and the longitudinal beam 2 form an overall frame structure and are embedded with the slope foot design embedding depth. The sawtooth-shaped force-bearing surface 5 is in a normal relationship with the direction of the downward force.

[0033] By forming an integral frame structure with crossbeam 1 and longitudinal beam 2 and embedding it into the slope to a certain depth, and by making the sawtooth force-bearing surface 5 in a normal relationship with the direction of the sliding force, it is possible to ensure that the frame structure is tightly embedded in the slope, so that the sawtooth force-bearing surface 5 can effectively bear the landslide thrust from above the slope and play its decomposition and transformation function.

[0034] This invention also provides a construction method for prestressed anchor cable sawtooth frame beams, comprising the following steps: S1. After the slope is trimmed and measured, clean and trim the slope to be reinforced, and lay out the horizontal beam 1, longitudinal beam 2, triangular force component block 4, enlarged foundation 6 and anchor cable holes according to the design position. S2. Utilizing the existing topography of the slope, using a combination of manual labor and small machinery, excavate the transverse beam groove and longitudinal beam groove along the layout position, and excavate multiple sequentially connected toothed grooves on the side of the longitudinal beam groove facing the slope according to the design requirements; excavate the enlarged foundation pit 6 at the lowest toothed groove, and form anti-slip steps 7 extending towards the inside of the slope at the base of the enlarged foundation pit. S3. Drill anchor holes at the corresponding positions of the tooth tops of the toothed grooves, extending the anchor holes to the stable rock layers of the slope; install anchor cable 3 in the anchor holes and grout the anchoring section of anchor cable 3. S4. Tie the crossbeam reinforcement, longitudinal beam reinforcement, triangular force block reinforcement and enlarged foundation reinforcement in the crossbeam groove, longitudinal beam groove, toothed groove and enlarged foundation pit respectively, and connect the crossbeam reinforcement, longitudinal beam reinforcement, triangular force block reinforcement and enlarged foundation reinforcement to form an integral reinforcement skeleton. S5. Install the templates for the crossbeam 1, longitudinal beam 2, triangular force component block 4 and enlarged foundation 6, and install the anchor plate and anchor pre-embedded parts for the anchor cable 3 to pass through at each tooth tip; S6. Pour concrete to form a reinforced concrete integral structure with the crossbeam 1, longitudinal beam 2, triangular component block 4 and enlarged foundation 6, and ensure that the triangular component block 4 is in close contact with the slope and cure the poured concrete. S7. After the concrete strength reaches the design requirements, the anchor cable 3 is tensioned in stages, and locked by the anchor after the tension force reaches the design prestress value. S8. Seal the anchorages and exposed anchor cables 3, and restore and protect the slope of the construction area.

[0035] This invention achieves coordinated stress distribution between the sawtooth frame beam and the anchor cable structure through a systematic process connection (excavation, hole drilling, grouting, integral reinforcement binding, integral casting, and staged tensioning). Specifically, the addition of sawtooth grooves and anti-slip steps 7 at the bottom of the enlarged foundation pit significantly enhances the interlocking ability between the frame beam and the slope, effectively resisting the slope's downward thrust. Connecting the reinforcing bars of the crossbeam 1, longitudinal beam 2, triangular force-bearing blocks 4, and enlarged foundation 6 into an integral skeleton and casting it in one go greatly improves the integrity and bending stiffness of the frame beam, avoiding weak points in force transmission caused by secondary construction. Then, the staged tensioning and locking process ensures that the prestress is applied evenly and controllably to the slope, resulting in significant active reinforcement and overall improving the reliability, durability, and construction safety of the slope reinforcement.

[0036] To further optimize the scheme, in step S2, the original slope is excavated according to the design outline of the sawtooth-shaped stress surface 5, so that the toothed grooves formed by the excavation are connected in sequence, and the triangular force component block 4 formed by casting is attached to the groove wall of the toothed groove; the enlarged foundation pit is excavated to the design bearing layer, and the bearing conditions of the foundation are checked; the inwardly inclined anti-slip step 7 is set and excavated and formed simultaneously with the enlarged foundation 6 pit.

[0037] By excavating according to the design contour of the sawtooth-shaped stress surface 5 and ensuring that the cast triangular force-bearing blocks 4 are tightly fitted to the trench wall, the contact area and frictional embedment effect between the stress surface and the original soil and rock of the slope are greatly increased. This allows the slope sliding force to be transferred to the frame structure more efficiently, improving the efficiency of the anti-sliding bearing capacity. At the same time, the enlarged foundation 6 is excavated to the design bearing layer and the bearing conditions of the base are tested. It is simultaneously formed with the inwardly inclined anti-sliding steps 7. This ensures that the foundation is located in a stable stratum and effectively resists the shear sliding of the slope along the free surface by utilizing the reverse resistance of the inclined steps. This significantly improves the anti-sliding and anti-overturning stability of the enlarged foundation. Moreover, the simultaneous excavation and forming simplifies the construction process and ensures the integrity of the original soil of the base.

[0038] Further optimizing the scheme, the anchor cable 3 passes through the top of the tooth of the triangular force component block 4 and is anchored in the stable bedrock of the slope. The anchor plate of the anchor cable 3 is set on the top surface of the tooth of the triangular force component block 4, and the prestress is directly transferred to the sawtooth force surface 5 through the tooth top. In step S3, after cleaning the anchor cable hole, the anchor cable 3 and the grouting pipe are installed, and grout is injected into the anchor cable hole through the grouting pipe so that the anchoring section of the anchor cable 3 is connected to the stable rock layer.

[0039] By precisely positioning the anchor cable at the top of the teeth of the triangular force component 4 and placing the anchor plate on the tooth top surface, the prestress of the anchor cable 3 can be transferred to the sawtooth-shaped stress surface 5 along the shortest and most direct mechanical path through the tooth top position. This effectively avoids moment concentration or excessive local stress caused by eccentric loading, ensuring the smooth and uniform diffusion of the prestress load and reducing the risk of torsional deformation of the frame beam. Furthermore, after cleaning the anchor cable holes, the anchor cable 3 and grouting pipe are installed and grouting is performed, ensuring full bonding between the grout in the anchoring section and the stable rock layer. This significantly improves the gripping force and pull-out bearing capacity of the anchor cable 3, ensuring that the prestress can be effectively locked in the stable bedrock for a long period.

[0040] To further optimize the scheme, in step S6, the longitudinal beam 2, the triangular force component block 4, and the enlarged foundation 6 are continuously cast and formed. When the casting needs to be done in sections due to construction conditions, a construction joint connection structure is set between adjacent casting sections. In step S7, after the concrete strength reaches the predetermined proportion of the design strength, the anchor cable 3 is prestressed in the order of pre-tensioning, graded tensioning, and locking, and the tension force at each stage and the elongation of the anchor cable are recorded.

[0041] By continuously casting the longitudinal beam 2, triangular force-bearing block 4, and enlarged foundation 6, and setting construction joint connection structures between adjacent casting sections, the feasibility of segmented construction on site is taken into account. Furthermore, the connection structure (such as roughening, keyway installation, or pre-reserved reinforcement) ensures a strong bond between the old and new concrete interfaces, preventing structural delamination and enhancing overall collaborative performance. Simultaneously, after the concrete strength reaches the predetermined proportion, prestress is applied strictly in the sequence of pre-tensioning, graded tensioning, and locking, with tension force and anchor cable elongation recorded throughout the process. This process effectively eliminates anchor cable slack and inelastic deformation, ensuring that the actual effective prestress of each anchor cable 3 accurately reaches the design value. It avoids over-tensioning that damages the structure or under-tensioning that leads to insufficient reinforcement, thus guaranteeing the prestress stability and structural safety margin of the slope under long-term service conditions.

[0042] The prestressed anchor cable sawtooth frame beam and its construction method provided by this invention are implemented as follows: First, after the slope is trimmed, the positions and outlines of each triangular force component 4 are accurately laid out on the slope according to the design drawings; utilizing the original topography of the slope, a combination of manual labor and small machinery is used to directly excavate the sawtooth-shaped force surface outline on the slope according to the design requirements of the sawtooth-shaped force surface 5, forming a toothed groove adapted to the original topography of the slope; at the position of the lowest force component, the foundation pit 6 is excavated according to the design dimensions and depth to ensure that the foundation is located on the slope. On stable undisturbed soil or undisturbed rock strata, an inwardly inclined anti-slip step 7 is set at the base; steel bars are tied in the excavated toothed groove and connected to the main reinforcement of the longitudinal beam 2; the enlarged foundation 6 is firmly connected to the sawtooth force block above and the main reinforcement of the longitudinal beam 2 through longitudinal steel bars; concrete is poured as a whole so that the triangular force block 4 fits tightly with the slope, and the enlarged foundation 6 and the longitudinal beam 2 are integrally cast; the anchor cable 3 passes through the tooth top position of the triangular force block 4 and is anchored in the stable bedrock of the slope; the anchor plate of the anchor cable 3 is set on the tooth top surface of the triangular force block 4 and prestress is applied.

[0043] In this invention, the designed landslide thrust P forms an angle θ with the horizontal plane and can be decomposed into a horizontal component Ph and a downward vertical component Pv. The line containing the normal to the bearing surface of the triangular force component 4 is substantially parallel to the direction of the designed landslide thrust P. When the slope transmits the landslide thrust P to the bearing surface, the bearing surface generates a normal reaction force N in the opposite direction to the landslide thrust P. The normal reaction force N can be decomposed into a horizontal reaction component Nh and an upward vertical reaction component Nv. The horizontal reaction component Nh resists the horizontal component Ph of the landslide thrust, and the vertical reaction component Nv resists the vertical component Pv of the landslide thrust, thereby reducing the slope's downward tendency.

[0044] The lowest enlarged foundation 6 transfers the vertical load of the frame beam to the bearing layer of the foundation and restricts the settlement of the frame beam through the base reaction force R. Anchor cables 3 apply prestress to the frame beam and transfer the load borne by the frame beam to the stable rock layer within the slip surface. The serrated stress surface 5, the enlarged foundation 6, and the anchor cables 3 work together to improve the overall stability of the frame beam and the slope. This invention, by setting a serrated stress surface with the normal line of the bearing surface basically parallel to the direction of the designed landslide thrust, enables each bearing surface to generate a normal reaction force on the slope opposite to the direction of the landslide thrust. The horizontal and vertical components of the normal reaction force resist the horizontal and downward components of the landslide thrust, which helps to reduce the downward trend of the slope and improve the stress state of the frame beam, effectively avoiding collapse and voiding. The anchor cable 3 passes through the top of the triangular component block 4, and the prestress is directly transferred to the sawtooth bearing surface 5 through the bearing surface of the tooth top, which is the shortest force transmission path and the most efficient. By setting an enlarged foundation 6 at the lowest component block, reliable upward support is provided, which effectively prevents the overall subsidence of the frame beam. The construction method of "topographic priority excavation and shaping" is adopted, and the component blocks are directly placed on the original soil or original rock mass, which ensures the close fit between the sawtooth bearing surface 5 and the slope, and the construction quality is reliable.

[0045] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A prestressed anchor cable sawtooth frame beam, characterized in that, The system includes a crossbeam (1), a longitudinal beam (2), anchor cables (3), and triangular force-bearing blocks (4). A sawtooth-shaped force-bearing surface (5) is provided on the longitudinal beam (2). The sawtooth-shaped force-bearing surface (5) is distributed along the height direction of the longitudinal beam (2). The sawtooth-shaped force-bearing surface (5) is composed of multiple triangular force-bearing blocks (4) arranged sequentially along the height direction of the longitudinal beam (2). Each triangular force-bearing block (4) has a bearing surface facing upwards from the slope. The straight line where the normal of the bearing surface is located is parallel to the direction of the designed landslide thrust, and the direction of the normal reaction force generated by the bearing surface on the slope is opposite to the direction of the designed landslide thrust. There are multiple anchor cables (3), and some of the triangular force-bearing blocks (4) correspond to the anchor cables (3). The anchor cables (3) pass through the tooth top position of the corresponding triangular force-bearing block (4) and are anchored in the stable bedrock of the slope. The anchor plate of the anchor cable (3) is set on the tooth top surface of the triangular force-bearing block (4).

2. The prestressed anchor cable sawtooth frame beam according to claim 1, characterized in that, An enlarged foundation (6) is provided at the lowest triangular force block (4). The enlarged foundation (6) extends into the inside of the slope and its bottom surface rests on a stable foundation bearing layer. The bottom area of ​​the triangular force block (4) is smaller than the bottom area of ​​the enlarged foundation (6).

3. The prestressed anchor cable sawtooth frame beam according to claim 2, characterized in that, The bottom surface of the enlarged foundation (6) is lower than the slope toe line and is embedded into the slope body at the designed embedment depth. The bottom surface of the enlarged foundation (6) is provided with anti-slip steps (7) that slope inward toward the inside of the slope body.

4. The prestressed anchor cable sawtooth frame beam according to claim 1, characterized in that, When the angle between the designed landslide thrust and the horizontal plane is θ, the angle between each bearing surface and the horizontal plane is determined according to θ, so that the straight line containing the normal of each bearing surface is parallel to the direction of the designed landslide thrust.

5. The prestressed anchor cable sawtooth frame beam according to claim 2, characterized in that, Both the triangular force-shaping block (4) and the enlarged foundation (6) are reinforced concrete structures and are integrally cast with the longitudinal beam (2).

6. The prestressed anchor cable sawtooth frame beam according to claim 1, characterized in that, The crossbeam (1) and the longitudinal beam (2) form an overall frame structure and are embedded in the slope foot design with a fixed depth. The sawtooth force-bearing surface (5) is in a normal relationship with the direction of the downward force.

7. A construction method for a prestressed anchor cable sawtooth frame beam according to any one of claims 1-6, characterized in that, Includes the following steps: S1. After the slope is trimmed and measured, the slope to be reinforced is cleaned and trimmed. The horizontal beam (1), longitudinal beam (2), triangular force component block (4), enlarged foundation (6) and anchor cable hole are laid out according to the design position. S2. Using the existing topography of the slope, the crossbeam groove and longitudinal beam groove are excavated along the layout position by means of manual labor and small machinery. On the side of the longitudinal beam groove facing the slope, multiple toothed grooves are excavated in sequence according to the design requirements. At the lowest toothed groove, an enlarged foundation (6) pit is excavated, and an anti-slip step (7) is formed on the base of the enlarged foundation pit extending towards the inside of the slope. S3. Drill anchor holes at the corresponding positions of the tooth tops of the toothed grooves, so that the anchor holes extend to the stable rock strata of the slope; install the anchor (3) in the anchor holes and grout the anchor section of the anchor (3); S4. Bind the crossbeam reinforcement, longitudinal beam reinforcement, triangular force block reinforcement and enlarged foundation reinforcement in the crossbeam groove, longitudinal beam groove, toothed groove and enlarged foundation pit respectively, and connect the crossbeam reinforcement, longitudinal beam reinforcement, triangular force block reinforcement and enlarged foundation reinforcement to form an integral reinforcement skeleton. S5. Install the templates for the crossbeam (1), longitudinal beam (2), triangular force component block (4) and enlarged foundation (6), and install the anchor plate and anchor pre-embedded parts for the anchor cable (3) to pass through at each tooth tip; S6. Pour concrete to form a reinforced concrete integral structure of the crossbeam (1), longitudinal beam (2), triangular force block (4) and enlarged foundation (6), so that the triangular force block (4) is closely attached to the slope and the poured concrete is cured. S7. After the concrete strength reaches the design requirements, the anchor cable (3) is tensioned in stages, and locked by the anchor after the tension force reaches the design prestress value. S8. The anchorage and exposed anchor cable (3) shall be sealed and the slope of the construction area shall be restored and protected.

8. The construction method of the prestressed anchor cable sawtooth frame beam according to claim 7, characterized in that, In step S2, the original slope is excavated according to the design outline of the sawtooth bearing surface, so that the toothed grooves formed by the excavation are connected in sequence, and the triangular force component block (4) formed by casting is attached to the groove wall of the toothed groove; the enlarged foundation pit is excavated to the design bearing layer, and the bearing conditions of the foundation are checked; the inwardly inclined anti-slip step (7) is set and the enlarged foundation (6) pit is excavated and formed simultaneously.

9. The construction method of the prestressed anchor cable sawtooth frame beam according to claim 7, characterized in that, The anchor cable (3) passes through the top of the tooth of the triangular force component block (4) and is anchored in the stable bedrock of the slope. The anchor plate of the anchor cable (3) is set on the tooth top surface of the triangular force component block (4). The prestress is directly transmitted to the sawtooth force surface (5) through the tooth top position. In step S3, after cleaning the anchor cable hole, the anchor cable (3) and the grouting pipe are installed, and grout is injected into the anchor cable hole through the grouting pipe so that the anchoring section of the anchor cable (3) is connected to the stable rock layer.

10. The construction method of the prestressed anchor cable sawtooth frame beam according to claim 1, characterized in that, In step S6, the longitudinal beam (2), the triangular force component block (4) and the enlarged foundation (6) are continuously cast and formed. When the construction conditions require segmented casting, a construction joint connection structure is set between adjacent casting segments. In step S7, after the concrete strength reaches the predetermined proportion of the design strength, the anchor cable (3) is prestressed in the order of pre-tensioning, graded tensioning and locking, and the tension force at each level and the elongation of the anchor cable are recorded.

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