Built-in resin prestressed multifunctional hollow anchor rod and construction method

Abstract

This invention provides a multifunctional hollow anchor bolt with built-in resin prestressing and its construction method. The hollow anchor bolt includes an anchoring section, one end of which is detachably equipped with an end assembly, and the other end of which is equipped with a push-in connecting pipe. The push-in connecting pipe is internally threaded to the anchor bolt body. A pad is provided at the free end of the anchor bolt body, and sealing connection assemblies are provided on both sides of the pad on the anchor bolt body. A data acquisition device is installed inside the anchor bolt body. This invention integrates anchoring, grouting, and monitoring functions into the same hollow anchor bolt, making it multifunctional and simplifying the construction process. Through the mechanical cooperation of a piston, bagged anchoring agent, and piercing blade, the rotational motion of the anchor bolt body is converted into axial compression of the bagged anchoring agent, achieving simultaneous drilling and anchoring agent release. The built-in data acquisition device in the hollow anchor bolt provides the hardware foundation for subsequent intelligent control and long-term monitoring, transforming the hollow anchor bolt from a support component into an intelligent monitoring terminal.

Description

Technical Field

[0001] This invention belongs to the field of tunnel engineering technology, specifically relating to a multifunctional hollow anchor rod with built-in resin prestressing and its construction method. Background Technology

[0002] In tunnel engineering, the stability of the surrounding rock and the performance of the support structure directly determine the safety of construction and the quality of the project.

[0003] Traditional anchor bolts exhibit unstable anchoring performance in complex geological environments, especially in weak or heterogeneous surrounding rock conditions, often resulting in insufficient anchoring force or ineffective bonding with the surrounding rock. Grouting processes often fail to achieve uniform distribution, and grouting pressure is difficult to control precisely, leading to poor surrounding rock reinforcement, particularly in areas with well-developed fractures.

[0004] Traditional construction methods are inefficient, often requiring multiple manual operations, resulting in long construction cycles. This is especially true in areas with complex geological conditions, where construction difficulty and time are significantly increased. Furthermore, existing anchor bolt technologies generally lack long-term monitoring capabilities, making it impossible to obtain real-time data on anchor bolt stress, deformation, and changes in the surrounding environment. Consequently, it is difficult to dynamically assess the support effectiveness.

[0005] Therefore, it is necessary to design a multifunctional hollow anchor rod with built-in resin prestressing and construction method to enhance anchoring performance, improve construction efficiency and quality, and solve the current technical problems. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a multifunctional hollow anchor bolt with built-in resin prestressing, a control system, and a construction method that enhances anchoring performance and improves construction efficiency and quality.

[0007] The technical solution of this invention is: a multifunctional hollow anchor rod with built-in resin prestressing, comprising: An anchoring section rod body, one end of which is detachably provided with an end assembly, the other end of which is provided with a push-in connecting pipe, the inside of which is threadedly connected to an anchor rod body, the free end of which is provided with a pad, the anchor rod body on both sides of which is provided with a sealing connection assembly, and the inside of which is provided with a data acquisition device; The end assembly has an end connecting pipe, one end of which is detachably and fixedly connected to the interior of the anchoring section rod, and the other end of which is fixedly provided with a stirring blade. An anchoring agent outlet is provided on the side of the end connecting pipe. The anchoring section rod body is provided with a bagged anchoring agent inside, and one end of the end connecting pipe is provided with a piercing blade corresponding to the bagged anchoring agent. A piston is provided inside the anchoring section rod body between the bagged anchoring agent and the anchor rod body. An anchoring section outlet is provided on one side of the anchoring section between the piston and the anchor rod body, and an anchor rod outlet is provided on one side of the anchor rod body; The data acquisition device includes a tool for collecting data on the stress, deformation, and temperature and humidity of the anchor rod and sending it to the control module.

[0008] Furthermore, the data acquisition device includes a data monitoring module and a data transmission module; The data monitoring module is used to collect data on the stress, deformation, and temperature and humidity of the anchor bolt body. The data transmission module is used to send data to the control module.

[0009] Furthermore, the sealing connection assembly includes a grout stop plug, a spherical washer, and a nut fitted onto the outside of the anchor bolt body; The grout stopper is located on the pad plate near the anchoring section of the rod, and the spherical washer is pressed and fixed on the other side of the pad plate by the nut.

[0010] The construction method of the multifunctional hollow anchor bolt with built-in resin prestressing as described above includes the following steps: Insert the hollow anchor rod into the borehole, rotate the anchor rod body to make it screw into the inside of the anchoring section rod body, and push the bagged anchoring agent to move through the piston, puncture and squeeze the bagged anchoring agent, so that the anchoring agent flows out from the anchoring agent outlet and fills the gap between the anchoring section rod body and the borehole. After the anchoring agent solidifies, grout is injected into the anchor rod body through a grouting pump. The grout flows out from the anchor rod outlet and the anchoring section outlet to fill the borehole. Prestress is applied to the anchor rod body through a prestressing loading device and then locked with nuts; The data acquisition device monitors the anchor bolt's stress, deformation, and ambient temperature and humidity in real time, and transmits the data to the control system.

[0011] Furthermore, during the process of rotating the anchor rod body to screw it into the anchoring section rod body, the threaded connection between the anchor rod body and the propulsion connecting pipe forms a spiral propulsion mechanism; When the anchor rod rotates forward, the anchor rod moves axially relative to the anchoring section rod, and at the same time pushes the piston to slide forward along the inner wall of the anchoring section rod. The piston front face squeezes the bagged anchoring agent and moves it towards the end assembly. During the movement, the bagged anchoring agent is punctured by the puncture blade and released. Under the continuous thrust of the piston, the anchoring agent is squeezed out through the anchoring agent outlet into the borehole.

[0012] Furthermore, the solidification time of the anchoring agent is determined by real-time monitoring of the interface temperature change between the anchoring section rod and the borehole using a data acquisition device. When the interface temperature rises to the preset temperature threshold and remains stable for more than the preset time value, it is determined that the anchoring agent has completed its initial setting. At this time, the grouting pump is started to inject grout into the anchor rod body. During the grouting process, the grout flows sequentially through the hollow inner cavity of the anchor rod body, the anchor rod outlet, the hollow inner cavity of the anchoring section rod body, and the anchoring section outlet, eventually filling the remaining voids in the borehole.

[0013] Furthermore, the step of injecting grout into the anchor bolt body using a grouting pump also includes: Real-time acquisition of grouting parameters, and transmission of grouting parameter data to the control system; The control system incorporates a grouting density prediction model based on a deep learning algorithm. This model dynamically adjusts the grouting pressure and grouting volume according to real-time flow rate, pressure, and rock mass characteristic parameters in the historical database. When a sudden drop in pressure or abnormal flow rate is detected, it automatically determines that the grouting is not dense or that the grout is leaking, triggering a supplementary grouting procedure.

[0014] Furthermore, in the step of applying prestress to the anchor rod body through the prestressing loading device, the prestressing loading is carried out in three stages: The first stage of loading is applied to 30% to 40% of the target prestress. After loading is completed, the load is maintained for 30 to 60 seconds, and the strain distribution data of the anchor rod body is read through the data acquisition device. If the axial strain deviation of the anchor rod is less than 5%, then a second-stage loading is applied until the target prestress reaches 70% to 80%. If the axial strain deviation is greater than or equal to 5%, the loading will be paused and a warning signal will be sent. After the second stage of loading is completed, the load is maintained for 30-60 seconds and strain data is read. Once the conditions are met, the third stage of loading is carried out to the target prestress value.

[0015] Furthermore, in the step of real-time monitoring of anchor bolt stress, deformation, and ambient temperature and humidity using a data acquisition device: The control module generates a strain distribution curve along the axial direction of the anchor rod body based on the strain data collected by the data monitoring module, and compares the curve with a preset standard strain distribution curve. When the strain value of a certain section on the measured curve deviates from the standard curve by more than 15% and the duration exceeds 2 hours, the control system determines that there is abnormal stress in that section and records the abnormal location information.

[0016] Furthermore, the construction method for the built-in resin prestressed multifunctional hollow anchor also includes a digital twin model construction step for the entire construction process: The control system synchronously integrates the rotational torque, axial thrust, and thrust speed data collected during the rotation of the anchor rod, the interface temperature change data during the solidification of the anchoring agent, the grouting pressure and grouting flow rate data during the grouting process, and the anchor rod strain distribution data during the prestressing loading process, according to the time sequence, to construct a digital twin model of the entire process of the anchor rod construction hole. The digital twin model dynamically displays the borehole outline, anchor bolt spatial position, anchoring agent diffusion range, grouting penetration boundary, and prestress distribution field in a three-dimensional visualization form, and compares the anchor bolt force and deformation data monitored in real time by the data acquisition device with the theoretical calculation values ​​in the model; When the deviation between the measured data and the theoretical value of the model exceeds a preset threshold, the control system automatically identifies the source of the deviation as abnormal geological conditions, deviation of construction parameters or structural damage, and generates corresponding handling suggestions.

[0017] The beneficial effects of this invention are: (1) This invention integrates anchoring, grouting and monitoring functions into the same hollow anchor rod, realizing multiple uses of one rod and simplifying the construction process; (2) Through the mechanical cooperation of piston, bagged anchoring agent and piercing blade, the rotational motion of anchor rod body is converted into axial compression of bagged anchoring agent, so as to realize the synchronous completion of drilling and anchoring agent release; (3) The built-in data acquisition device of the hollow anchor provides a hardware foundation for subsequent intelligent control and long-term monitoring of construction, transforming the hollow anchor from a single support component into an intelligent monitoring terminal; (4) Integrate deep learning grouting density prediction model, graded prestressing loading control, distributed optical fiber monitoring and other technologies to realize intelligent perception, adaptive control and abnormal early warning in the construction process; (5) By constructing a digital twin model, we can realize the full-process visualization, traceability and health diagnosis from construction to operation, and provide data support for the long-term stability of tunnel support. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the multifunctional hollow anchor rod with built-in resin prestressing in this invention.

[0019] Figure 2 This is a schematic diagram of the control system for the built-in resin prestressed multifunctional hollow anchor bolt in this invention.

[0020] Figure 3 This is a flowchart of the construction method for the multifunctional hollow anchor rod with built-in resin prestressing in this invention. Detailed Implementation

[0021] Various exemplary embodiments of the invention will now be described in detail with reference to the accompanying drawings. The descriptions of the exemplary embodiments are merely illustrative and are in no way intended to limit the invention or its application or use. The invention can be embodied in many different forms and is not limited to the embodiments described herein. These embodiments are provided to make the invention thorough and complete, and to fully express the scope of the invention to those skilled in the art. It should be noted that, unless otherwise specifically stated, the relative arrangement of components and steps, the composition of materials, numerical expressions, and values ​​set forth in these embodiments should be interpreted as merely exemplary and not as limiting.

[0022] The terms "first," "second," and similar words used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different parts. Words such as "including" or "comprising" mean that the element preceding the word encompasses the element listed after it, without excluding the possibility of encompassing other elements. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0023] like Figure 1 As shown, a multifunctional hollow anchor rod 10 with built-in resin prestressing is disclosed. The hollow anchor rod 10 includes: An anchoring section rod 12, one end of which is detachably provided with an end assembly 11, and the other end of which is provided with a push-in connecting pipe 15. An anchor rod 18 is internally threaded to the push-in connecting pipe 15. A pad 16 is provided at the free end of the anchor rod 18. Sealing connection assemblies 17 are provided on the anchor rod 18 on both sides of the pad 16. A data acquisition device 19 is provided inside the anchor rod 18. The end assembly 11 has an end connecting pipe 112. One end of the end connecting pipe 112 is detachably and fixedly connected to the inside of the anchoring section rod 12. The other end of the end connecting pipe 112 is fixedly provided with a stirring blade 111. An anchoring agent outlet 113 is provided on the side of the end connecting pipe 112. The anchoring section rod 12 is provided with a bagged anchoring agent 13 inside, and one end of the end connecting pipe 112 is provided with a piercing blade 114 corresponding to the bagged anchoring agent 13. A piston 14 is provided inside the anchoring section rod 12 between the bagged anchoring agent 13 and the anchor rod 18. An anchoring section outlet 121 is provided on one side of the anchoring section 12 between the piston 14 and the anchor rod 18, and an anchor rod outlet 181 is provided on one side of the anchor rod 18. The data acquisition device 19 includes a system for acquiring data on the stress, deformation, and temperature and humidity of the anchor rod 18 and sending it to the control module.

[0024] In this embodiment, anchoring, grouting, and monitoring functions are integrated into the same hollow anchor rod 10, achieving multiple uses with one rod and simplifying the construction process. Through the mechanical cooperation of the piston 14, the bagged anchoring agent 13, and the piercing blade 114, the rotational motion of the anchor rod body 18 is converted into axial compression of the bagged anchoring agent 13, realizing the synchronous completion of drilling and anchoring agent release. The hollow anchor rod 10 has a built-in data acquisition device 19, which provides the hardware foundation for subsequent intelligent control and long-term monitoring of construction, transforming the hollow anchor rod 10 from a single support component into an intelligent monitoring terminal.

[0025] In some embodiments, the data acquisition device 19 includes a data monitoring module 191 and a data transmission module 192; the data monitoring module 191 is used to collect data on the stress, deformation, and temperature and humidity of the anchor rod; the data transmission module 192 is used to send the data to the control module.

[0026] Specifically, the data monitoring module 191 uses fiber optic grating sensing technology to realize real-time acquisition of the stress, deformation and ambient temperature and humidity of the anchor rod 18; the data transmission module 192 packages the processed stress, deformation, temperature and humidity data and sends them to the control system in real time via wireless communication.

[0027] As an example, multiple fiber Bragg grating sensors are arranged at axial intervals along the anchor rod body 18. The fiber Bragg grating sensors are divided into three categories, including force monitoring gratings, temperature monitoring gratings, and humidity sensors.

[0028] When the anchor rod is subjected to load and undergoes strain, the center wavelength of the reflected light from the stress monitoring grating drifts, and the amount of wavelength drift is proportional to the strain. The current wavelength of each grating is collected in real time, and the wavelength drift of the temperature-compensated grating is subtracted to eliminate the temperature effect. Based on the strain coefficient calibrated in the laboratory, the net wavelength drift is converted into a strain value. The axial stress is calculated according to Hooke's Law and then multiplied by the cross-sectional area to obtain the axial force. The strain difference between adjacent measuring points is used to calculate the local deformation, and the strain difference between symmetrically arranged upper and lower measuring points is used to calculate the curvature.

[0029] The temperature-compensated grating remains in a free state, and its wavelength drift is caused only by temperature changes, which is directly converted into a temperature value. The surface of the humidity sensor is coated with a moisture-sensitive material. After absorbing moisture, the volume expands, stretching the grating and causing wavelength drift, which is then converted into relative humidity after temperature correction.

[0030] In some embodiments, the sealing connection assembly 17 includes a grout stop plug 171, a spherical washer 172, and a nut 173 fitted onto the outside of the anchor rod body 18. The grout stop plug 171 is disposed on the pad 16 near the anchor section rod body 12, and the spherical washer 172 is pressed and fixed to the other side of the pad 16 by the nut 173. The grout stop plug 171 forms an effective seal between the pad 16 and the orifice, preventing grout from leaking out of the orifice during grouting and ensuring grouting pressure. The spherical washer 172 cooperates with the nut 173 to provide a stable locking force after prestressing loading, preventing prestress loss. The spherical washer 172 can adapt to the angular deviation of the anchor rod body 18, ensuring that the pad 16 is in close contact with the surrounding rock surface and improving the uniformity of stress distribution.

[0031] In the above embodiments, the bagged anchoring agent 13 is filled with epoxy resin or polyurethane resin; before construction, after the end assembly 11 is removed from the anchoring section rod 12, the bagged anchoring agent 13 is filled into the anchoring section rod 12.

[0032] The multifunctional hollow anchor bolt with built-in resin prestressing described in the above embodiments requires the use of a corresponding construction control system during construction, such as... Figure 2 As shown, the control system includes a prestressing loading device 20, a grouting pump 40, and a control module 50. The prestressing loading device 20 is installed at one end of the hollow anchor rod 10 and is used to apply prestress to the hollow anchor rod 10. The grouting pump 40 is connected to the hollow anchor rod 10 through a grouting pipe 30 and is used to pump grout into the hollow anchor rod 10. The control module 50 is connected to the prestressing loading device 20 and the grouting pump 40 through control cables 60. The data acquisition device 19 is wirelessly connected to the control module 50. The control system automatically exports all monitoring data during construction for later analysis.

[0033] In some embodiments, such as Figure 3 As shown, a construction method for a multifunctional hollow anchor bolt with built-in resin prestressing based on any of the above embodiments is disclosed, including the following steps: Insert the hollow anchor rod 10 into the borehole, rotate the anchor rod body 18 to make it screw into the anchoring section rod body 12, and push the bagged anchoring agent to move through the piston 14, puncture and squeeze the bagged anchoring agent, so that the anchoring agent flows out from the anchoring agent outlet and fills the gap between the anchoring section rod body and the borehole. After the anchoring agent solidifies, grout is injected into the anchor rod body through a grouting pump. The grout flows out from the anchor rod outlet and the anchoring section outlet to fill the borehole. Prestress is applied to the anchor rod body by the prestressing loading device 20 and then locked by the nut; The data acquisition device monitors the anchor bolt's stress, deformation, and ambient temperature and humidity in real time, and transmits the data to the control system.

[0034] In some embodiments, the above construction method further includes an initial preparation step, which specifically includes the following steps: When drilling, the hole diameter is generally Φ50-100mm, and the hole depth is determined according to the design. Connect the hollow anchor rod 10 to the push-in connecting sleeve 15 by left-hand rotation, and screw the anchor rod body 18 in about 50mm; take out the end assembly 11 by right-hand rotation, put the bagged anchoring agent 13 in, and then screw the end assembly 11 back on. Insert the assembled hollow anchor rod 10 into the drill hole, ensuring that the anchor rod is in the correct position and at the correct angle; rotate the anchor rod body 18 to screw it into the anchoring section body 12, and at the same time puncture the bagged anchoring agent 13 to squeeze the anchoring agent into the anchor hole. After pushing it to the rock wall, continue rotating the anchor rod body 18 for 10 seconds, and drive the anchoring section rod body 12 to rotate together, thereby stirring the resin and making it solidify quickly; after 1 minute of constant strength, turn on the hydraulic tensioning system to apply a temporary prestress of >60KN to the anchor rod, and tighten the nut.

[0035] In some embodiments, during the process of rotating the anchor rod 18 to screw it into the anchoring section rod 12, the threaded connection between the anchor rod 18 and the propulsion connecting pipe 15 forms a spiral propulsion mechanism; when the anchor rod 18 rotates forward, the anchor rod 18 moves axially relative to the anchoring section rod 12, and at the same time pushes the piston 14 to slide forward along the inner wall of the anchoring section rod 12, and the front end face of the piston 14 squeezes the bagged anchoring agent 13 to move it towards the end assembly 11. During the movement, the bagged anchoring agent 13 is punctured by the puncturing blade 114 and the anchoring agent is released. Under the continuous propulsion of the piston 14, the anchoring agent is squeezed out into the borehole through the anchoring agent outlet 113. By linking the rotary drilling and anchoring agent extrusion actions together through a helical propulsion mechanism, a single power source can perform two functions, simplifying the operation process. The anchoring agent is uniformly extruded under the continuous propulsion of the piston 14 and the action of the piercing blade 114, avoiding the problem of uneven mixing in traditional manual methods. The anchoring agent is released synchronously during drilling, achieving simultaneous drilling and anchoring, and shortening the waiting time after anchor installation.

[0036] In some embodiments, the time point for the solidification of the anchoring agent is determined by real-time monitoring of the interface temperature change between the anchoring section rod 12 and the borehole by the data acquisition device 19. When the interface temperature rises to the preset temperature threshold and remains stable for more than the preset time value, it is determined that the anchoring agent has completed its initial setting. At this time, the grouting pump 40 is started to inject grout into the anchor rod body. During grouting, the grout flows sequentially through the hollow cavity of the anchor rod body 18, the anchor rod outlet 181, the hollow cavity of the anchoring section rod body 12, and the anchoring section outlet 121, ultimately filling the remaining voids in the borehole. Utilizing the exothermic properties of resin curing, the solidification state of the anchoring agent is accurately determined through temperature monitoring, avoiding premature grouting that could damage the uncured anchoring agent or delayed grouting that could affect the construction progress. Temperature-triggered grouting initiates the process, achieving automatic connection between anchoring and grouting procedures and reducing errors from manual judgment.

[0037] In one specific implementation, the interface temperature between the anchoring section 12 and the borehole is collected by axially spaced fiber optic temperature sensors on the inner wall of the anchoring section 12. Thermally conductive silicone grease is filled between the temperature sensors and the inner wall of the anchoring section 12 to ensure good thermal contact. Before anchor installation, the initial temperature of each sensor is collected as a reference value. After the anchor is inserted into the borehole and the anchoring agent is squeezed out by rotating the anchoring section 12, the temperature sensors continuously collect the real-time temperature at each measuring point and send it to the control module 50 via the data transmission module 192. The control module 50 calculates the temperature change value in real time. When the temperature change value rises to a preset threshold and remains stable for a period of time, it is determined that the anchoring agent has completed its initial setting. During implementation, the preset temperature change threshold and holding time can be determined by simulating construction through test holes.

[0038] In some embodiments, the step of grouting the anchor rod body 18 by the grouting pump 40 further includes: real-time acquisition of grouting parameters and transmission of the grouting parameter data to the control system; the control system embeds a grouting density prediction model based on a deep learning algorithm, which dynamically adjusts the grouting pressure and grouting volume according to real-time flow rate, pressure and rock mass characteristic parameters in the historical database, and automatically determines that the grouting is not dense or the grout is leaking when a sudden drop in pressure or abnormal flow rate is detected, triggering a supplementary grouting procedure.

[0039] Deep learning models learn grouting patterns based on historical data, enabling them to predict optimal grouting parameters under current geological conditions and ensure grouting effectiveness. Pressure and flow rate are dynamically adjusted based on real-time grouting parameters to adapt to changes in geological conditions, avoiding insufficient or wasted grouting caused by traditional grouting methods. The system automatically identifies grouting fault characteristics such as sudden pressure drops and abnormal flow rates, triggering immediate supplementary grouting procedures to prevent grouting defects from remaining. Through intelligent judgment and supplementary grouting mechanisms, the system significantly improves the grouting density compliance rate, ensuring support quality.

[0040] Specifically, during the grouting process, parameters such as grouting pressure, grouting flow rate, cumulative grouting volume, and grouting time are collected. The grouting pressure is obtained by a pressure sensor installed on the grouting pipe 30, the grouting flow rate is obtained by a flow meter installed at the outlet of the grouting pump 40, the cumulative grouting volume is obtained by integrating the flow rate and used to determine whether the total grouting volume meets the design requirements, and the grouting time records the duration of grouting and is used to analyze the stability of the grouting process.

[0041] The control module 50 incorporates a deep learning-based grouting density prediction model. This model employs a deep neural network architecture, and its training dataset comprises geological characteristic parameters accumulated from historical engineering projects, such as rock mass integrity index, fracture development degree, and groundwater seepage flow, as well as process characteristic parameters for corresponding borehole locations, including grouting pressure, grouting flow rate, and cumulative grouting volume. Ultrasonic testing of grouting density after completion serves as the label data. Through offline training, the model can establish a nonlinear mapping relationship between grouting parameters and grouting density. During actual grouting, the model dynamically adjusts the output pressure and grouting volume of the grouting pump based on real-time collected grouting pressure and flow data, combined with the local geological conditions reflected by the torque fluctuation characteristics and propulsion resistance characteristics obtained during the drilling stage, ensuring that the grouting parameters are always kept within the optimal range. When the grouting parameters deviate from the expected values, the model can adaptively adjust the control strategy to ensure that the grout fully penetrates and fills the fractures in the surrounding rock.

[0042] Meanwhile, the model continuously monitors the stability of the grouting process. When a significant drop in grouting pressure is detected within a short period, or when the grouting flow rate fluctuates drastically and exceeds the normal range, the model automatically determines that the grouting is not dense enough or that grout leakage has occurred. At this point, the control module immediately triggers a supplementary grouting procedure, suspends the current grouting, adjusts the grouting parameters based on the abnormal characteristics, and restarts grouting to fill the defective area. A drop in grouting pressure exceeding 2 MPa within 5 seconds is considered a significant drop.

[0043] In some embodiments, the step of applying prestress to the anchor rod body by the prestressing loading device 20 is carried out in three stages: The first stage of loading is applied to 30% to 40% of the target prestress. After loading is completed, the load is maintained for 30 to 60 seconds, and the strain distribution data of the anchor rod body is read through the data acquisition device. If the axial strain deviation of the anchor rod is less than 5%, then a second-stage loading is applied until the target prestress reaches 70% to 80%. If the axial strain deviation is greater than or equal to 5%, the loading will be paused and a warning signal will be sent. After the second stage of loading is completed, the load is maintained for 30-60 seconds and strain data is read. Once the conditions are met, the third stage of loading is carried out to the target prestress value.

[0044] Specifically, the prestressing loading device 20 employs a hydraulic tensioning system, including a hydraulic cylinder, a hydraulic pump, a clamping system, pressure sensors, and a control valve assembly, connected to the control module 50 via a control cable 60. The hydraulic cylinder, the core component providing tension force, is typically made of high-strength steel, possessing high-pressure and wear-resistant properties. The hydraulic pump provides high-pressure fluid to the hydraulic cylinder, driving the tensioning device to complete the prestressing loading. The clamping system, used to fix the end of the anchor bolt and transmit tension force, often includes anchor bolt clamps or wedge-shaped clamps. The pressure sensor monitors the pressure value within the hydraulic cylinder in real time to calculate the actual applied tension force. The control valve assembly includes a relief valve, a directional valve, and a pressure regulating valve, used to adjust the flow direction and pressure of the hydraulic oil, ensuring precise control of the tension force. Multiple fiber optic grating sensors arranged along the axial direction of the anchor bolt monitor the strain data at each measuring point in real time and transmit it to the control module 50 via wireless communication.

[0045] At the start of the loading process, the control module first determines the target prestress value according to the design requirements. Then, the control module activates the hydraulic tensioning system for the first stage of loading, increasing the prestress to between 30% and 40% of the target value. After loading is complete, the system maintains this load state for 30 to 60 seconds, during which time the data acquisition device continuously reads the strain distribution data at various measuring points on the anchor bolt and transmits it to the control module.

[0046] After receiving the strain data after the first stage of loading, the control module 50 calculates the uniformity of strain distribution along the anchor bolt axis. Specifically, the control module 50 analyzes the deviation between the strain value at each measuring point and the average strain value to obtain an axial strain deviation index. If the deviation is less than 5%, it indicates that the anchor bolt is under uniform stress and has good adaptability to the surrounding rock, and the control module allows for the second stage of loading, increasing the prestress to between 70% and 80% of the target value. Conversely, if the axial strain deviation is greater than or equal to 5%, it indicates that there is stress concentration or unevenness in the anchor bolt, and the control module immediately pauses the loading process and sends a warning signal through the display screen or alarm device to remind the operator to check for possible geological anomalies or anchor bolt installation problems. The decision to continue loading is made only after the problems have been identified and resolved.

[0047] After the second stage of loading is completed, the system maintains the load for 30 to 60 seconds and again reads the strain distribution data of the anchor bolt through the data acquisition device. The control module re-evaluates the uniformity of the strain distribution. If the deviation is less than 5%, the third stage of loading is performed to finally increase the prestress to the target value. If the strain deviation is still too large after the second stage of loading, the system will repeat the process of pausing loading and sending a prompt signal.

[0048] In some embodiments, in the step of real-time monitoring of anchor bolt stress, deformation, and ambient temperature and humidity using a data acquisition device: The control module generates a strain distribution curve along the axial direction of the anchor rod body based on the strain data collected by the data monitoring module, and compares the curve with a preset standard strain distribution curve. When the strain value of a certain section on the measured curve deviates from the standard curve by more than 15% and the duration exceeds 2 hours, the control system determines that there is abnormal stress in that section and records the abnormal location information.

[0049] In some embodiments, the construction method for built-in resin prestressed multifunctional hollow anchor bolts further includes a step of constructing a digital twin model of the entire construction process: The control system will synchronously integrate the rotational torque, axial thrust, and thrust speed data collected during the rotation of the anchor rod, the interface temperature change data during the solidification of the anchoring agent, the grouting pressure and grouting flow data during the grouting process, and the anchor rod strain distribution data during the prestressing loading process, according to the time sequence, to construct a digital twin model of the entire process of the anchor rod construction hole. The digital twin model dynamically displays the borehole outline, anchor bolt spatial position, anchoring agent diffusion range, grouting penetration boundary, and prestress distribution field in a three-dimensional visualization form, and compares the anchor bolt force and deformation data monitored in real time by the data acquisition device with the theoretical calculation values ​​in the model; When the deviation between the measured data and the theoretical value of the model exceeds a preset threshold, the control system automatically identifies the source of the deviation as abnormal geological conditions, deviation of construction parameters or structural damage, and generates corresponding handling suggestions.

[0050] Specifically, during the process of rotating the anchor bolt body to screw it into the anchoring section, the data acquisition device collects drilling parameters in real time, such as rotational torque, axial thrust, and thrust speed. These data reflect the characteristics of rock strata changes and drilling resistance during the drilling process. During the anchoring agent solidification stage, the data acquisition device continuously monitors the temperature change at the interface between the anchoring section and the borehole, using the temperature rise curve to determine the solidification process of the anchoring agent. During grouting, real-time data on grouting pressure and flow rate are collected and transmitted to the control system, reflecting the penetration state of the grout in the surrounding rock fissures. During the prestressing loading stage, fiber optic grating sensors arranged along the anchor bolt axis collect strain distribution data at each measuring point, revealing the stress field distribution characteristics of the anchor bolt under stress.

[0051] The control system synchronously merges all the collected data along a unified timeline, eliminating the heterogeneity caused by different sampling frequencies and data formats, and forming a complete construction process dataset for the anchor bolt hole from the start of drilling to the completion of prestressing loading. Based on this data, the system constructs a full-process digital twin model of the hole.

[0052] This digital twin model dynamically displays each stage of the construction process in a three-dimensional visualization. Based on torque and thrust data during drilling, the model inverts the actual borehole contour and rock interface location, generating a three-dimensional geometric model of the borehole. The spatial position and orientation of the anchor bolts are precisely marked in the model. Simultaneously, the diffusion range of the anchoring agent in the borehole, the penetration boundary of the grout in the surrounding rock fissures, and the stress distribution field formed after prestressing are all presented visually, making the previously invisible interaction between the surrounding rock and the anchor bolts intuitively visible.

[0053] Once the digital twin model is built, the control system will continuously compare and analyze the anchor bolt stress and deformation data monitored in real time by the data acquisition device with the theoretical calculation values ​​in the model. The theoretical calculation values ​​are obtained based on rock mechanics models and finite element simulations, reflecting the stress state that the anchor bolt should have under design conditions. When the deviation between the measured data and the theoretical values ​​of the model exceeds a preset threshold, the control system automatically initiates a diagnostic program to identify the source of the deviation based on its characteristic patterns.

[0054] For example, if a local abrupt change occurs in a certain section of the measured strain distribution curve while other sections remain normal, the model can determine that there is a risk of structural damage due to local fracture zones or cavities in the surrounding rock. If the overall strain value is generally lower than the theoretical value, the model can determine that there is a loss during the prestressing process or a deviation in the anchor bolt installation. If the grouting pressure curve deviates systematically from the theoretical model, the model can determine that the grouting parameter settings need to be adjusted. Based on the identified sources of deviation, the control system generates corresponding treatment suggestions, such as suggesting reinforcement grouting for that section, suggesting checking the anchor bolt locking device, or suggesting adjusting the grouting parameters of adjacent holes, and pushes these suggestions to engineering technicians via a display screen or mobile terminal.

[0055] The various embodiments of the present invention have now been described in detail. To avoid obscuring the concept of the invention, some details known in the art have not been described. Those skilled in the art will fully understand how to implement the technical solutions disclosed herein based on the above description.

[0056] The embodiments described above only illustrate some implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A multifunctional hollow anchor bolt with built-in resin prestressing, characterized in that, include: An anchoring section rod body, one end of which is detachably provided with an end assembly, the other end of which is provided with a push-in connecting pipe, the inside of which is threadedly connected to an anchor rod body, the free end of which is provided with a pad, the anchor rod body on both sides of which is provided with a sealing connection assembly, and the inside of which is provided with a data acquisition device; The end assembly has an end connecting pipe, one end of which is detachably and fixedly connected to the interior of the anchoring section rod, and the other end of which is fixedly provided with a stirring blade. An anchoring agent outlet is provided on the side of the end connecting pipe. The anchoring section rod body is provided with a bagged anchoring agent inside, and one end of the end connecting pipe is provided with a piercing blade corresponding to the bagged anchoring agent. A piston is provided inside the anchoring section rod body between the bagged anchoring agent and the anchor rod body. An anchoring section outlet is provided on one side of the anchoring section between the piston and the anchor rod body, and an anchor rod outlet is provided on one side of the anchor rod body; The data acquisition device includes a tool for collecting data on the stress, deformation, and temperature and humidity of the anchor rod and sending it to the control module.

2. The multifunctional hollow anchor bolt with built-in resin prestressing according to claim 1, characterized in that: The data acquisition device includes a data monitoring module and a data transmission module; The data monitoring module is used to collect data on the stress, deformation, and temperature and humidity of the anchor bolt body. The data transmission module is used to send data to the control module.

3. The multifunctional hollow anchor bolt with built-in resin prestressing according to claim 1, characterized in that: The sealing connection assembly includes a grout stopper, a spherical washer, and a nut fitted on the outside of the anchor rod body; The grout stopper is located on the pad plate near the anchoring section of the rod, and the spherical washer is pressed and fixed on the other side of the pad plate by the nut.

4. A construction method based on the built-in resin prestressed multifunctional hollow anchor rod according to any one of claims 1 to 3, characterized in that, Includes the following steps: Insert the hollow anchor rod into the borehole, rotate the anchor rod body to make it screw into the inside of the anchoring section rod body, and push the bagged anchoring agent to move through the piston, puncture and squeeze the bagged anchoring agent, so that the anchoring agent flows out from the anchoring agent outlet and fills the gap between the anchoring section rod body and the borehole. After the anchoring agent solidifies, grout is injected into the anchor rod body through a grouting pump. The grout flows out from the anchor rod outlet and the anchoring section outlet to fill the borehole. Prestress is applied to the anchor rod body through a prestressing loading device and then locked with nuts; The data acquisition device monitors the anchor bolt's stress, deformation, and ambient temperature and humidity in real time, and transmits the data to the control system.

5. The construction method of the built-in resin prestressed multifunctional hollow anchor rod according to claim 4, characterized in that, During the process of rotating the anchor rod body to screw it into the anchoring section rod body, the threaded connection between the anchor rod body and the propulsion connecting pipe forms a spiral propulsion mechanism. When the anchor rod rotates forward, the anchor rod moves axially relative to the anchoring section rod, and at the same time pushes the piston to slide forward along the inner wall of the anchoring section rod. The piston front face squeezes the bagged anchoring agent and moves it towards the end assembly. During the movement, the bagged anchoring agent is punctured by the puncture blade and released. Under the continuous thrust of the piston, the anchoring agent is squeezed out through the anchoring agent outlet into the borehole.

6. The construction method of the built-in resin prestressed multifunctional hollow anchor rod according to claim 4, characterized in that, The solidification time of the anchoring agent is determined by real-time monitoring of the interface temperature change between the anchoring section rod and the borehole using a data acquisition device. When the interface temperature rises to the preset temperature threshold and remains stable for more than the preset time value, it is determined that the anchoring agent has completed its initial setting. At this time, the grouting pump is started to inject grout into the anchor rod body. During the grouting process, the grout flows sequentially through the hollow inner cavity of the anchor rod body, the anchor rod outlet, the hollow inner cavity of the anchoring section rod body, and the anchoring section outlet, eventually filling the remaining voids in the borehole.

7. The construction method of the built-in resin prestressed multifunctional hollow anchor rod according to claim 4, characterized in that, The step of injecting grout into the anchor bolt body using a grouting pump further includes: Real-time acquisition of grouting parameters, and transmission of grouting parameter data to the control system; The control system incorporates a grouting density prediction model based on a deep learning algorithm. This model dynamically adjusts the grouting pressure and grouting volume according to real-time flow rate, pressure, and rock mass characteristic parameters in the historical database. When a sudden drop in pressure or abnormal flow rate is detected, it automatically determines that the grouting is not dense or that the grout is leaking, triggering a supplementary grouting procedure.

8. The construction method of the built-in resin prestressed multifunctional hollow anchor rod according to claim 4, characterized in that, In the step of applying prestress to the anchor rod body through the prestressing loading device, the prestressing loading is carried out in three stages: The first stage of loading is applied to 30% to 40% of the target prestress. After loading is completed, the load is maintained for 30 to 60 seconds, and the strain distribution data of the anchor rod body is read through the data acquisition device. If the axial strain deviation of the anchor rod is less than 5%, then a second-stage loading is applied until the target prestress reaches 70% to 80%. If the axial strain deviation is greater than or equal to 5%, the loading will be paused and a warning signal will be sent. After the second stage of loading is completed, the load is maintained for 30-60 seconds and strain data is read. Once the conditions are met, the third stage of loading is carried out to the target prestress value.

9. The construction method of the built-in resin prestressed multifunctional hollow anchor rod according to claim 4, characterized in that, In the step of real-time monitoring of anchor bolt stress, deformation, and ambient temperature and humidity using a data acquisition device: The control module generates a strain distribution curve along the axial direction of the anchor rod body based on the strain data collected by the data monitoring module, and compares the curve with a preset standard strain distribution curve. When the strain value of a certain section on the measured curve deviates from the standard curve by more than 15% and the duration exceeds 2 hours, the control system determines that there is abnormal stress in that section and records the abnormal location information.

10. The construction method of the built-in resin prestressed multifunctional hollow anchor rod according to claim 4, characterized in that: It also includes the steps for building a digital twin model of the entire construction process: The control system synchronously integrates the rotational torque, axial thrust, and thrust speed data collected during the rotation of the anchor rod, the interface temperature change data during the solidification of the anchoring agent, the grouting pressure and grouting flow rate data during the grouting process, and the anchor rod strain distribution data during the prestressing loading process, according to the time sequence, to construct a digital twin model of the entire process of the anchor rod construction hole. The digital twin model dynamically displays the borehole outline, anchor bolt spatial position, anchoring agent diffusion range, grouting penetration boundary, and prestress distribution field in a three-dimensional visualization form, and compares the anchor bolt force and deformation data monitored in real time by the data acquisition device with the theoretical calculation values ​​in the model; When the deviation between the measured data and the theoretical value of the model exceeds a preset threshold, the control system automatically identifies the source of the deviation as abnormal geological conditions, deviation of construction parameters or structural damage, and generates corresponding handling suggestions.

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