Soft rock high and steep slope toughening and reinforcing construction process

Abstract

The application discloses a kind of soft rock high steep slope toughening reinforcement construction technology, comprising: S1, slope grading excavation is immediately sprayed flexible modified material to form closed layer;S2, utilize eccentric drilling tool with pipe drilling and adopt mechanical reaming drill bit to form inverted conical enlarged space at hole bottom;S3, the toughness anchoring assembly assembled with high-strength steel strand, centering support, grouting pipe is placed into drilling, and installs energy dissipation device outside slope;S4, segmented pressure grouting and secondary splitting reinforcement, form radial reinforced rock mass area;S5, grading tensioning and dynamic locking;S6, re-paving water-resisting layer, ecological drainage plant soil layer and vegetation layer.The application blocks the path of soft rock disintegration by water through closure, cooperates with fiber toughening grouting to improve anchoring reliability by mechanical reaming, uses controlled friction slip of energy dissipation device to dissipate rock deformation energy and cooperates with displacement sensor to realize safety early warning, which significantly improves the durability, safety and maintainability of slope reinforcement protection.

Description

Technical Field

[0001] This invention relates to the field of roadbed slope construction technology, and in particular to a toughening and reinforcement construction process for steep soft rock slopes. Background Technology

[0002] As my country's expressway network gradually shifts from "densification" to "expansion," the number of projects upgrading existing four-lane expressways to six-lane or eight-lane highways is increasing year by year. Expansion primarily involves widening on one or both sides, inevitably resulting in extensive excavation work on high rock slopes. Among these, soft rock slopes, due to their low strength, well-developed structural surfaces, and susceptibility to softening when exposed to water, are highly susceptible to deformation, instability, and even landslides during excavation. This not only seriously threatens construction safety but also significantly impacts the normal operation of existing roads. Traditional reinforcement methods, such as anchor bolts, shotcrete, and retaining walls, can improve slope stability to some extent, but their toughening properties are insufficient for the special geological conditions of soft rock slopes. They are unable to effectively adapt to long-term deformation and dynamic loads, leading to unsatisfactory reinforcement results and high maintenance costs. Therefore, developing a reinforcement construction process that can significantly improve the toughness and overall stability of soft rock slopes has become a key technical problem urgently needing to be solved in current expressway expansion projects. Summary of the Invention

[0003] To address the aforementioned problems, this invention provides a construction process for toughening and reinforcing steep soft rock slopes, comprising the following steps: S1, graded excavation and immediate closure of slope surface: the slope is divided into multiple excavation steps according to the design height of the slope and the physical and mechanical parameters of soft rock, the cracked soft rock slope is cleaned, and a flexible modified material is sprayed on the exposed soft rock surface to form a sealing layer. S2, directional drilling and bottom mechanical reaming, uses an eccentric drill bit to perform casing drilling to form a borehole. After drilling to the designed depth of the anchoring section, the mechanical reaming drill bit is replaced and cut is performed at the bottom of the hole under hydraulic drive to form an inverted conical enlarged space. S3, the assembly and insertion of the tough anchoring component will be carried out by inserting the high-strength steel strand, centering bracket, and grouting pipe into the borehole. The energy dissipation device is installed between the anchor plate and the anchor head lock on the outside of the slope to dissipate the deformation energy of the rock mass through controlled frictional sliding. S4, segmented pressure grouting and secondary splitting reinforcement: cement grout containing toughening fibers is injected into the hole through the grouting pipe to form a grouting body. After the initial grouting reaches the initial setting state, secondary splitting grouting is performed under high pressure to form a radial reinforced rock mass zone in the soft rock surrounding the grouting body. S5, graded tensioning and dynamic locking: After the grouting body reaches the design strength, the high-strength steel strand is tensioned in stages by hydraulic equipment, and the high-strength steel strand is locked at the power output end of the energy dissipation device by the anchor head locker. S6, a waterproof layer, an ecologically permeable soil layer, and a vegetation layer are laid on the outside of the sealed layer.

[0004] As a further explanation of the present invention, in step S1, the sealing layer is formed by spraying epoxy AB adhesive, and its construction thickness is controlled between 2mm and 5mm.

[0005] Furthermore, in step S2, the drilling process uses casing to provide instantaneous radial support to the borehole wall to cope with the diameter reduction and borehole collapse characteristics of soft rock formations; the geometric parameters of the inverted conical enlarged space satisfy the following: its maximum diameter is 1.5 to 1.8 times the conventional diameter of the borehole, and the axial length of the inverted conical enlarged space is set to 1 / 4 to 1 / 3 of the total length of the anchoring section.

[0006] Furthermore, the energy dissipation device includes: The friction sleeve has its inner wall ground, and the surface roughness Ra is controlled between 0.8μm and 1.6μm. A sliding core column is coaxially disposed inside the friction sleeve, with one end connected to the anchor head locker, serving as a direct load-bearing component for anchor cable tension. If the stress adjustment bolt group is to be intervened, it is arranged radially along the circumferential side of the friction sleeve to adjust the normal pressure between the friction interfaces; A high-friction coefficient composite liner is filled between the inner wall of the friction sleeve and the outer wall of the sliding core, and the static friction coefficient of the composite liner is not less than 0.45.

[0007] Furthermore, the high-friction coefficient composite liner is made of a semi-metallic friction material; a high-precision displacement sensor is integrated on the side of the sliding core column, and the displacement sensor (16) is used to collect the axial sliding distance of the sliding core column (11) relative to the friction sleeve (10) in real time and transmit the displacement data to the remote monitoring terminal.

[0008] Furthermore, the frictional resistance provided by the energy dissipation device (9) is quantitatively set by adjusting the tightening force of the prestressing adjusting bolt group (12), and is set to 80%-90% of the design ultimate bearing capacity of the high-strength steel strand (6).

[0009] Furthermore, in step S4, the grout used for grouting is M30 grade cement mortar, and polypropylene fibers accounting for 0.5% to 1.2% of the cement weight are added to the grout mix. The length of the polypropylene fibers is selected to be 12mm to 19mm. The polypropylene fibers form a three-dimensional randomly distributed mesh support structure inside the grout body (18) to improve the crack resistance, toughness and radial splitting resistance of the grout body (18) under tension load.

[0010] Furthermore, the grouting process in step S4 is as follows: First, the initial grouting is performed through the first grouting pipe, and the grouting pressure is controlled at 0.5MPa to 1.0MPa, so that the grout fills the inverted conical enlarged space (5) and the entire anchoring section; after the grout injected for the first time enters the initial setting state after 6 to 12 hours, the second high-pressure grouting pipe is started to perform secondary splitting grouting. At this time, the grouting pressure is increased to 2.5MPa to 5.0MPa, and the high-pressure grout forcibly cuts and fills the micro-cracks of the soft rock mass, thereby forming the reinforced rock mass zone (17) around the grouting body (18) and improving the shear strength of the anchoring interface.

[0011] Furthermore, in step S5, the graded tensioning procedure is executed by an automated hydraulic device, and the tensioning load is set sequentially to 25%, 50%, 75% and 100% of the design load, and the load is held for observation for no less than 10 minutes under each load level; after reaching 100% of the design load, an additional 10% over-tensioning is performed to compensate for the initial elongation loss of the anchoring system and the shrinkage deformation when the anchor head is locked. After the displacement observation is stable, the tension of the high-strength steel strand (6) is transmitted to the sliding core column (11) through the anchor head locker (15).

[0012] Furthermore, when the soft rock mass displaces outwards due to rheology and moves the anchor plate (14), the sliding core column (11) slides within the friction sleeve (10) and dissipates mechanical energy as heat. The monitoring terminal receives feedback from the displacement sensor (16) in real time. When the cumulative sliding displacement reaches 80% of the effective length of the friction sleeve (10), the system triggers a structural safety warning, prompting the corresponding support node to be stress reset or reinforced.

[0013] The beneficial effects of this invention are: This invention modifies disintegrating soft rock by spraying an epoxy AB adhesive sealing layer and then lays a water-resistant layer and an ecologically permeable vegetation layer on the outer side of the slope to effectively block the path of soft rock disintegration and softening upon contact with water. It employs mechanically enlarged holes with an inverted conical shape at the bottom, combined with cement mortar incorporating polypropylene fibers. The fibers form a three-dimensional network support structure within the grout, significantly improving the crack resistance and toughness of the grout. Secondary splitting grouting creates a radially reinforced rock mass zone around the grout, greatly increasing the shear strength of the anchoring interface. An energy-dissipating device converts the rheological deformation energy of the rock mass into heat energy dissipation through controlled sliding of the friction sleeve and sliding core, preventing stress concentration that could lead to brittle fracture of the anchor cable. An integrated high-precision displacement sensor monitors the sliding amount in real time, and the accumulated displacement automatically triggers a safety warning, achieving a leap from passive load-bearing to active toughness control. Attached Figure Description

[0014] Figure 1 This is a flowchart illustrating the construction process for toughening and reinforcing steep soft rock slopes according to an embodiment of the present invention. Figure 2 This is a diagram illustrating the toughening and reinforcement structure for steep soft rock slopes according to an embodiment of the present invention. Figure 3 This is a schematic diagram of the cross-sectional structure for toughening and reinforcing steep soft rock slopes according to an embodiment of the present invention; Figure 4 This is a structural diagram of the energy dissipation device according to an embodiment of the present invention.

[0015] Attached reference numerals: 1. Slope; 2. Step; 3. Sealing layer; 4. Borehole; 5. Enlarged space; 6. High-strength steel strand; 7. Centering support; 8. Grouting pipe; 9. Energy dissipation device; 10. Friction sleeve; 11. Sliding core column; 12. Prestressed adjusting bolt group; 13. High friction coefficient composite liner; 14. Anchor plate; 15. Anchor head locker; 16. High-precision displacement sensor; 17. Reinforced rock mass zone; 18. Grouting body. Detailed Implementation

[0016] Example:

[0017] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0018] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., 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.

[0019] As attached Figure 1-4As shown in this embodiment, a construction process for toughening and reinforcing a steep soft rock slope includes the following steps: S1, graded excavation and immediate closure of slope surface: Based on the design height of slope 1 and the physical and mechanical parameters of soft rock, slope 1 is divided into multiple excavation steps 2, and the cracked soft rock slope is cleaned. Within a predetermined time after the formation of each excavation step 2, a flexible modified material is sprayed on the exposed soft rock surface to form a sealing layer 3. S2, Directional drilling and bottom mechanical reaming: Using an eccentric drill bit to perform casing drilling to form a borehole 4, after drilling to the designed depth of the anchoring section, the mechanical reaming drill bit is replaced and cutting is performed at the bottom of the hole under hydraulic drive to form an inverted conical enlarged space 5. S3, Assembly and insertion of the tough anchoring component: The component consisting of high-strength steel strand 6, centering bracket 7, grouting pipe 8 and energy dissipation device 9 installed outside the slope 1 is inserted into the hole. The energy dissipation device 9 is located between the anchor plate 14 and the anchor head locker 15 and is used to dissipate the deformation energy of the rock mass through controlled frictional sliding. S4, segmented pressure grouting and secondary splitting reinforcement: cement grout containing toughening fibers is injected into the hole through grouting pipe 8 to form grouting body 18. After the grout injected initially reaches the initial setting state, secondary splitting grouting is performed under high pressure to form a radial reinforced rock mass zone 17 in the soft rock surrounding the grouting body 18. S5, graded tensioning and dynamic locking: After the grouting body 18 reaches the design strength, the high-strength steel strand 6 is graded tensioned by hydraulic equipment, and the high-strength steel strand 6 is locked at the power output end of the energy dissipation device 9 by the anchor head locker 15. During the slope protection period, when the anchor cable tension caused by rock mass rheology exceeds the preset sliding resistance of the energy dissipation device 9, the energy dissipation device 9 generates an axial relative displacement to maintain constant anchor cable stress. S6, a waterproof layer, an ecologically permeable soil layer, and a vegetation layer are laid on the outside of the sealing layer 3.

[0020] This invention modifies disintegrating soft rock by spraying an epoxy AB adhesive sealing layer and then lays a water-resistant layer and an ecologically permeable vegetation layer on the outer side of the slope to effectively block the path of soft rock disintegration and softening upon contact with water. It employs mechanically enlarged holes with an inverted conical shape at the bottom, combined with cement mortar incorporating polypropylene fibers. The fibers form a three-dimensional network support structure within the grout, significantly improving the crack resistance and toughness of the grout. Secondary splitting grouting creates a radially reinforced rock mass zone around the grout, greatly increasing the shear strength of the anchoring interface. An energy-dissipating device converts the rheological deformation energy of the rock mass into heat energy dissipation through controlled sliding of the friction sleeve and sliding core, preventing stress concentration that could lead to brittle fracture of the anchor cable. An integrated high-precision displacement sensor monitors the sliding amount in real time, and the accumulated displacement automatically triggers a safety warning, achieving a leap from passive load-bearing to active toughness control.

[0021] Specifically, in this embodiment, in step S1, the excavation height of each excavation step 2 is set between 8 meters and 12 meters; the construction time window of the sealing layer 3 is limited to within 2 hours after the excavation is completed, in order to cut off the heat and moisture exchange between the soft rock mass and the atmosphere and inhibit weathering and spalling; the sealing layer 3 is formed by spraying epoxy AB glue and other high molecular polymer sealants, and its construction thickness is controlled between 2 mm and 5 mm, and the physical properties of the sealing layer 3 meet the requirement that the elongation at break is not less than 200%, so as to ensure that the sealing layer 3 maintains structural integrity and does not crack under the initial rebound deformation caused by the unloading of the rock mass.

[0022] Specifically, in this embodiment, in step S2, the drilling process uses casing to provide instantaneous radial support to the borehole wall to cope with the diameter reduction and borehole collapse characteristics of soft rock formations; the geometric parameters of the inverted conical enlarged space 5 satisfy: its maximum diameter is 1.5 to 1.8 times the conventional diameter of the borehole 4, and the axial length of the inverted conical enlarged space 5 is set to 1 / 4 to 1 / 3 of the total length of the anchoring section; by changing the force mode of the anchoring section through the inverted conical enlarged space 5, the single sidewall frictional resistance is transformed into a composite force transmission system of sidewall frictional resistance and end resistance, thereby alleviating the shear stress concentration at the head of the anchoring section.

[0023] Specifically, in this embodiment, the energy dissipation device 9 includes: The friction sleeve 10 has its inner wall ground, and the surface roughness Ra is controlled between 0.8μm and 1.6μm. The sliding core column 11 is coaxially disposed inside the friction sleeve 10, and one end of it is connected to the anchor head locker 15, serving as a direct load-bearing component for anchor cable tension. If the intervention stress adjustment bolt group 12 is arranged radially along the circumferential side of the friction sleeve 10, it is used to adjust the normal pressure between the friction interfaces; A high-friction coefficient composite liner 13 is filled between the inner wall of the friction sleeve 10 and the outer wall of the sliding core 11, and the static friction coefficient of the composite liner 13 is not less than 0.45.

[0024] Specifically, in this embodiment, the high-friction coefficient composite liner 13 is made of a semi-metallic friction material, and its mechanical properties are configured such that when the instantaneous high temperature generated during the sliding energy dissipation process reaches 400°C, its friction coefficient does not undergo thermal decay; a high-precision displacement sensor 16 is integrated on the side of the sliding core 11, and the displacement sensor 16 is used to collect the axial sliding distance of the sliding core 11 relative to the friction sleeve 10 in real time, and transmit the displacement data to the remote monitoring terminal.

[0025] Specifically, in this embodiment, the frictional resistance provided by the energy dissipation device 9 is quantitatively set by adjusting the tightening force of the prestressing adjusting bolt group 12, and is set to 80%-90% of the design ultimate bearing capacity of the high-strength steel strand 6.

[0026] Specifically, in this embodiment, in step S4, the grout used for grouting is M30 grade cement mortar, and polypropylene fibers accounting for 0.5% to 1.2% of the cement weight are added to the grout mix. The length of the polypropylene fibers is selected to be 12mm to 19mm. The polypropylene fibers form a three-dimensional randomly distributed mesh support structure inside the grout body 18 to improve the crack resistance, toughness and radial splitting resistance of the grout body 18 under tension load.

[0027] Specifically, in this embodiment, the grouting process in step S4 is as follows: First, the initial grouting is performed through the first grouting pipe, with the grouting pressure controlled between 0.5 MPa and 1.0 MPa, so that the grout fills the inverted conical enlarged space 5 and the entire anchoring section; after the grout injected in the initial stage enters the initial setting state after 6 to 12 hours, the second high-pressure grouting pipe is started to perform secondary splitting grouting, at which time the grouting pressure is increased to 2.5 MPa to 5.0 MPa, and the high-pressure grout forcibly cuts and fills the micro-fractures of the soft rock mass, thereby forming the reinforced rock mass zone 17 around the grouting body 18 and improving the shear strength of the anchoring interface.

[0028] Specifically, in this embodiment, in step S5, the graded tensioning procedure is executed by an automated hydraulic device. The tensioning load is set sequentially to 25%, 50%, 75%, and 100% of the design load, and the load is held for observation for no less than 10 minutes under each load level. After reaching 100% of the design load, an additional 10% over-tensioning is performed to compensate for the initial elongation loss of the anchoring system and the shrinkage deformation when the anchor head is locked. After the displacement observation stabilizes, the tension of the high-strength steel strand 6 is transferred to the sliding core column 11 through the anchor head locker 15.

[0029] Specifically, in this embodiment, during the slope protection period, when the soft rock mass displaces outward due to rheology and moves the anchor plate 14, if the axial force of the anchor cable is greater than the frictional resistance, the sliding core column 11 slides within the friction sleeve 10 and dissipates mechanical energy as heat. The monitoring terminal receives feedback from the displacement sensor 16 in real time. When the cumulative sliding displacement reaches 80% of the effective length of the friction sleeve 10, the system triggers a structural safety warning, prompting the stress to be reset or reinforced at the support node.

[0030] The above description only illustrates preferred embodiments of the present invention and should not be construed as limiting the scope of the claims. The present invention is not limited to the above embodiments, and variations in its specific structure are permitted. In short, all variations made within the scope of the independent claims of the present invention are within the scope of protection of the present invention.

Claims

1. A construction technique for toughening and reinforcing steep soft rock slopes, characterized in that, Includes the following steps: S1, graded excavation of slope and immediate closure of slope surface. According to the design height of slope (1) and the physical and mechanical parameters of soft rock, slope (1) is divided into multiple excavation steps (2). Cracked soft rock slope is cleaned up, and flexible modified material is sprayed on the exposed soft rock surface to form a sealing layer (3). S2, directional drilling and bottom mechanical reaming, using an eccentric drill bit to perform casing drilling to form a borehole (4), after drilling to the designed depth of the anchoring section, replace the mechanical reaming drill bit and perform cutting at the bottom of the hole under hydraulic drive to form an inverted conical enlarged space (5). S3, the assembly and insertion of the tough anchoring component will be carried out by inserting the high-strength steel strand (6), centering bracket (7), grouting pipe (8) into the borehole (4) as a component. The energy dissipation device (9) is installed between the anchor plate (14) and the anchor head lock (15) set outside the slope (1) to dissipate the deformation energy of the rock mass through controlled frictional sliding. S4, segmented pressure grouting and secondary splitting reinforcement, cement grout containing toughening fibers is injected into the hole through the grouting pipe (8) to form a grouting body (18), and after the grout injected for the first time reaches the initial setting state, secondary splitting grouting is performed under high pressure to form a radial reinforced rock mass zone (17) in the soft rock outside the grouting body (18). S5, graded tensioning and dynamic locking: after the grouting body (18) reaches the design strength, the high-strength steel strand (6) is graded tensioned by hydraulic equipment, and the high-strength steel strand (6) is locked at the power output end of the energy dissipation device (9) by the anchor head locker (15). S6, a waterproof layer, an ecologically permeable soil layer, and a vegetation layer are laid on the outside of the sealed layer.

2. The construction technology for toughening and reinforcing steep soft rock slopes according to claim 1, characterized in that: In step S1, the sealing layer (3) is formed by spraying epoxy AB adhesive, and its construction thickness is controlled between 2mm and 5mm.

3. The construction technology for toughening and reinforcing steep soft rock slopes according to claim 1, characterized in that: In step S2, the drilling process uses casing to provide instantaneous radial support to the borehole wall in order to cope with the diameter reduction and borehole collapse characteristics of soft rock formations; the geometric parameters of the inverted conical enlarged space (5) satisfy: its maximum diameter is 1.5 to 1.8 times the conventional diameter of the borehole (4), and the axial length of the inverted conical enlarged space (5) is set to 1 / 4 to 1 / 3 of the total length of the anchoring section.

4. The construction technology for toughening and reinforcing steep soft rock slopes according to claim 1, characterized in that: The energy dissipation device (9) includes: The friction sleeve (10) has its inner wall ground, and the surface roughness Ra is controlled between 0.8 μm and 1.6 μm. The sliding core column (11) is coaxially disposed inside the friction sleeve (10), and one end of it is connected to the anchor head lock (15) as a direct bearing component of the anchor cable tension; If the stress adjustment bolt group (12) is arranged radially along the circumference of the friction sleeve (10), it is used to adjust the normal pressure between the friction interfaces; A high-friction coefficient composite liner (13) is filled between the inner wall of the friction sleeve (10) and the outer wall of the sliding core (11), and the static friction coefficient of the composite liner (13) is not less than 0.

45.

5. The construction technology for toughening and reinforcing steep soft rock slopes according to claim 4, characterized in that: The high friction coefficient composite liner (13) is made of a semi-metallic friction material; a high-precision displacement sensor (16) is integrated on the side of the sliding core (11). The displacement sensor (16) is used to collect the axial sliding distance of the sliding core (11) relative to the friction sleeve (10) in real time and transmit the displacement data to the remote monitoring terminal.

6. The construction technology for toughening and reinforcing steep soft rock slopes according to claim 4, characterized in that: The frictional resistance provided by the energy dissipation device (9) is quantitatively set by adjusting the tightening force of the prestressing adjusting bolt group (12), and is set to 80%-90% of the design ultimate bearing capacity of the high-strength steel strand (6).

7. The construction technology for toughening and reinforcing steep soft rock slopes according to claim 1, characterized in that: In step S4, the grout used for grouting is M30 grade cement mortar, and polypropylene fibers accounting for 0.5% to 1.2% of the cement weight are added to the grout mix. The length of the polypropylene fibers is selected to be 12mm to 19mm. The polypropylene fibers form a three-dimensional randomly distributed mesh support structure inside the grout body (18) to improve the crack resistance, toughness and radial splitting resistance of the grout body (18) under tension load.

8. The construction technology for toughening and reinforcing steep soft rock slopes according to claim 1, characterized in that: The grouting process in step S4 is as follows: First, the initial grouting is performed through the first grouting pipe, and the grouting pressure is controlled at 0.5MPa to 1.0MPa, so that the grout fills the inverted conical enlarged space (5) and the entire anchoring section; after the grout injected for the first time enters the initial setting state after 6 to 12 hours, the second high-pressure grouting pipe is started to perform secondary splitting grouting. At this time, the grouting pressure is increased to 2.5MPa to 5.0MPa, and the high-pressure grout forcibly cuts and fills the micro-cracks of the soft rock mass, thereby forming the reinforced rock mass zone (17) around the grouting body (18) and improving the shear strength of the anchoring interface.

9. The construction technology for toughening and reinforcing steep soft rock slopes according to claim 1, characterized in that: In step S5, the graded tensioning procedure is executed by an automated hydraulic device. The tensioning load is set sequentially to 25%, 50%, 75% and 100% of the design load, and the load is held for observation for no less than 10 minutes under each load level. After reaching 100% of the design load, an additional 10% over-tensioning is performed to compensate for the initial elongation loss of the anchoring system and the shrinkage deformation when the anchor head is locked. After the displacement observation is stable, the tension of the high-strength steel strand (6) is transmitted to the sliding core column (11) through the anchor head locker (15).

10. The construction technology for toughening and reinforcing steep soft rock slopes according to claim 1, characterized in that: When the soft rock mass displaces outwards due to rheology and moves the anchor plate (14), the sliding core column (11) slides inside the friction sleeve (10) and dissipates mechanical energy into heat energy; the monitoring terminal receives feedback from the displacement sensor (16) in real time. When the cumulative sliding displacement reaches 80% of the effective length of the friction sleeve (10), the system triggers a structural safety warning and prompts the corresponding support node to be stress reset or reinforced.

Images