Intelligent monitoring and tension supplementing system and method for pre-stressed anchor cable

Abstract

The invention discloses a pre-stressed anchor cable intelligent monitoring and tension supplementing system and method.The system comprises an executing mechanism, a displacement sensor, an anchor backing plate, a first directional sliding anchorage device, a displacement hydraulic jack and a second directional sliding anchorage device, and the anchor backing plate, the first directional sliding anchorage device, the displacement hydraulic jack and the second directional sliding anchorage device are sequentially arranged on an anchor cable in a sleeving mode; a hydraulic cavity of the displacement hydraulic jack is connected with the executing mechanism through a pipeline; the displacement sensor is used for monitoring the change value of the elongation of the anchor cable in real time and transmitting the change value to the data processing terminal, and the data processing terminal is used for determining the axial force of the anchor cable according to monitoring data of the displacement sensor, comparing the axial force of the anchor cable with a set prestress value and outputting a control signal to the executing mechanism according to a comparison result. The actuating mechanism adjusts hydraulic pressure in a hydraulic cavity of the displacement hydraulic jack according to the control signal, so that a sliding telescopic rod of the displacement hydraulic jack transmits force to the anchor cable, and active supplementary tensioning of the prestress of the anchor cable is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of intelligent monitoring and tensioning of prestressed anchor cables, and in particular to a system and method for intelligent monitoring and tensioning of prestressed anchor cables. Background Art

[0002] The prestressed anchor cable system is an active support structure with high tensile strength. It is often used for tunnel rock faces and foundation pit slope support. One end of the cable anchor head is tightly combined with the rock and soil under the action of mortar, and the free end can be tensioned to actively reinforce the weak interlayer and sliding surface of the rock and soil. After the grouting of the anchor cable channel is completed, when the slurry strength meets the tensioning conditions, the prestressed tensioning and anchoring of the anchor cable are carried out to make the support system meet the design strength requirements. The degree of loss of prestress after the anchor cable is anchored is the key to the deformation control effect of the system. Affected by factors such as material properties and construction, the loss value of the prestress of the anchor cable can reach more than 60%. It is often necessary to use multiple supplementary tensioning methods to ensure the control value of the prestress of the anchor cable.

[0003] At present, the vibrating-string anchor dynamometer commonly used in engineering projects cannot realize real-time monitoring and feedback of the anchor axial force, and is easily affected by factors such as ambient temperature and construction, making it difficult to accurately judge the magnitude of the anchor axial force value; in addition, with the excavation of the foundation pit, the anchor cables that were pre-tensioned in the later stage of construction often do not have the conditions for supplementary tensioning, and the later prestressing of the anchor cables is difficult to maintain the prestressing design value, making it difficult to give full play to the deformation control performance of the active flexible support system.

[0004] Therefore, it is necessary to design an intelligent monitoring and tensioning system and construction method for prestressed anchor cables. The system can realize real-time monitoring, transmission and feedback of the axial force of the anchor cables, and actively tension the prestressed anchor cables in a timely manner, which is conducive to giving full play to the deformation control advantages of the flexible support system and accurately guiding the foundation pit construction. Summary of the invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art, and proposes a prestressed anchor cable intelligent monitoring and tensioning system and method.

[0006] The technical solution of the present invention is implemented as follows: The present invention provides a prestressed anchor cable intelligent monitoring and tensioning system, comprising an actuator, a displacement sensor, and an anchor plate, a first directional sliding anchor, a displacement hydraulic jack, and a second directional sliding anchor, which are sequentially sleeved on the anchor cable. The anchor plate, the first directional sliding anchor, the displacement hydraulic jack, and the second directional sliding anchor are all provided with through holes for the anchor cable to pass through. The anchor plate is located between the anchoring pedestal and the first directional sliding anchor. The hydraulic chamber of the displacement hydraulic jack is connected to the actuator through a pipeline.

[0007] The displacement sensor is used to monitor the change in the elongation of the anchor cable in real time and transmit it to the data processing terminal. The data processing terminal is used to determine the axial force of the anchor cable based on the monitoring data of the displacement sensor, compare the axial force of the anchor cable with the set prestress value, and output a control signal to the actuator based on the comparison result, so that the actuator can adjust the hydraulic pressure in the hydraulic cavity of the displacement hydraulic jack according to the control signal to achieve active tensioning of the anchor cable prestress.

[0008] Further, the displacement hydraulic jack includes a first cylinder body, the first cylinder body is provided with an annular through hole, the annular through hole extends along the length direction of the anchor cable, a first sliding telescopic rod is provided at one end of the annular through hole of the first cylinder body, one end of the first sliding telescopic rod extends out of the first cylinder body and abuts against the first directional sliding anchor, the other end of the first sliding telescopic rod is connected to a first sliding telescopic rod piston, the first sliding telescopic rod piston slides with the annular through hole of the first cylinder body, a second sliding telescopic rod is provided at the other end of the through hole of the first cylinder body, one end of the second sliding telescopic rod extends out of the first cylinder body and abuts against the second directional sliding anchor, the other end of the second sliding telescopic rod is connected to a second sliding telescopic rod piston, the second sliding telescopic rod piston slides with the annular through hole of the first cylinder body, and a first hydraulic chamber is formed between the first sliding telescopic rod piston and the second sliding telescopic rod piston.

[0009] Furthermore, the displacement sensor is connected between the first sliding telescopic rod piston and the second sliding telescopic rod piston.

[0010] Furthermore, the first directional sliding anchor and the second directional sliding anchor include an annular positioning sleeve and a plurality of one-way fastening clips, the annular positioning sleeve is provided with a conical through hole, the plurality of one-way fastening clips are located in the annular positioning sleeve and surround the outer periphery of the anchor cable, and the outer wall of the one-way fastening clip is gap-matched with the through hole wall of the annular positioning sleeve.

[0011] Furthermore, the actuator includes a second cylinder body and a piston rod, one end of the piston rod extends out of the second cylinder body and is connected to the driving device, the other end of the piston rod is connected to one side of the piston, the piston and the second cylinder body are slidably matched, and a second hydraulic chamber is formed between the other side of the piston and the second cylinder body, and the second hydraulic chamber of the actuator is connected to the first hydraulic chamber of the displacement hydraulic jack through a pipeline.

[0012] Furthermore, the driving device comprises a motor, a driving gear is arranged on the motor shaft of the motor, the piston rod is a threaded rod, a threaded rod is provided with a transmission gear, and the transmission gear is meshed with the driving gear.

[0013] Furthermore, a temperature sensor and a pressure sensor are provided in the actuator, and the temperature sensor and the pressure sensor are connected to a wireless transmitter. The temperature sensor is used to monitor the temperature of the hydraulic pressure in the actuator in real time, and transmit it to the data processing terminal via the wireless transmitter; the pressure sensor is used to monitor the hydraulic pressure in the actuator in real time, and transmit it to the data processing terminal via the wireless transmitter.

[0014] The present invention provides a method for intelligent monitoring and tensioning of prestressed anchor cables, comprising the following steps: receiving monitoring data collected by a sensor, analyzing and processing the received monitoring data to obtain the axial force of the anchor cable, and comparing the axial force of the anchor cable with a set prestress value, and outputting a control signal to an actuator according to the comparison result, so that the actuator can adjust the hydraulic pressure in the hydraulic cavity of a displacement hydraulic jack according to the control signal, so that the sliding telescopic rod of the displacement hydraulic jack transmits force to the anchor cable, thereby realizing active tensioning of the prestressed anchor cable.

[0015] Furthermore, the method for intelligent monitoring and tensioning of prestressed anchor cables of the present invention also includes the following steps: sending instructions to the actuator to adjust the hydraulic pressure in the hydraulic cavity of the actuator and the displacement hydraulic jack, so that the pressure on the sliding telescopic rod on the displacement hydraulic jack is consistent with the anchor rod anchoring prestress, so that the axial force of the anchor cable is completely transmitted to the front anchoring platform through the sliding telescopic rod.

[0016] Furthermore, the prestressed anchor cable intelligent monitoring and tensioning method of the present invention further includes the following steps: determining the elastic fulcrum stiffness coefficient of the anchor cable system at any time by analyzing the changes in the axial force and elongation of the anchor cable, specifically including:

[0017] The displacement sensor is used to obtain the deformation of the anchor cable at any time and calculate the stiffness coefficient of the elastic support. The calculation formula is:

[0018] Δl=Δl F +Δl T

[0019] Δl T =α·l s ΔT

[0020] Then the stiffness coefficient k of the elastic support is expressed as:

[0021]

[0022] Where: A is the cross-sectional area of ​​the sliding telescopic rod of the displacement hydraulic sensor; P0 is the hydraulic pressure of the hydraulic chamber when the anchor cable is anchored; P1 is the hydraulic pressure of the hydraulic chamber during acquisition; Δl is the change in the elongation of the anchor cable; Δl F is the change in anchor cable elongation caused by the change in anchor cable axial force, and ΔF is the change in anchor cable axial force.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The present invention can realize automatic anchoring of the anchor cable after directional deformation through a directional sliding anchor; realize force transmission between the axial force of the anchor cable and the anchoring pedestal through a displacement hydraulic jack, and the displacement sensor in its hydraulic chamber can monitor the change in elongation of the anchor cable when factors such as temperature and construction conditions change; the temperature and pressure changes of the hydraulic oil can be monitored in real time through the temperature and pressure sensors in the second hydraulic chamber of the rotary jacking hydraulic; the collected data can be sent to the data processing terminal through a wireless transmitter to monitor the axial force of the anchor cable in real time, and determine whether it is necessary to pre-stress the anchor cable by judgment. When necessary, an instruction can be sent to the power motor to realize active pre-stressing of the anchor cable through the power system; the present invention can realize intelligent monitoring and tensioning of the axial force of the prestressed anchor cable during the construction process through automatic collection, real-time transmission, intelligent interpretation and active feedback of information such as anchor cable deformation, ambient temperature and oil pressure, and can determine the accurate calculation of the stiffness coefficient of the elastic fulcrum of the pile-anchor structure through processing and analysis.

[0025] The various parts of the present invention are detachable, which is convenient for equipment transportation and replacement of damaged parts; in order to increase the service life of the material, the equipment material can be made of stainless steel or the surface can be coated with anti-rust spray paint. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A cross-sectional view of a prestressed anchor cable intelligent monitoring and tensioning system provided by an embodiment of the present invention;

[0027] Figure 2 A schematic diagram of the structure of the anchor cable directional sliding anchor provided by an embodiment of the present invention;

[0028] Figure 3 A schematic diagram of the structure of a one-way fastening clip provided in an embodiment of the present invention;

[0029] Figure 4 A schematic diagram of the structure of a displacement hydraulic jack provided in an embodiment of the present invention;

[0030] Figure 5 A schematic diagram of the structure of an actuator provided in an embodiment of the present invention;

[0031] Figure 6 A schematic diagram of the structure of a transmission gear provided by an embodiment of the present invention;

[0032] Figure 7 A flow chart of a method for intelligent monitoring and tensioning of prestressed anchor cables provided in an embodiment of the present invention.

[0033] In the accompanying drawings, 1 is an anchor cable, 2 is an anchoring pedestal, 3 is an anchor pad, 4 is a displacement hydraulic jack, 41 is a first sliding telescopic rod, 42 is a second sliding telescopic rod, 43 is a first hydraulic chamber, 44 is a first sliding telescopic rod piston, 45 is a second sliding telescopic rod piston, 46 is a displacement sensor, 47 is a jack hydraulic oil valve, 5 is a first directional sliding anchor, 6 is a second directional sliding anchor, 61 is an annular positioning sleeve, 611 is an annular positioning groove, 612 is a conical through hole, 62 is a one-way fastening clip, 7 is a hydraulic cylinder, 71 is a threaded rod, 72 is a transmission gear, 73 is a piston, 74 is a second hydraulic chamber, 75 is a cylinder hydraulic oil valve, 8 is a power motor, 9 is a data processing terminal, 10 is a wireless transmitter, 11 is a temperature and pressure sensor, and 12 is a pipeline. DETAILED DESCRIPTION

[0034] In order to enable those skilled in the art to better understand the technical solution of the present invention, the technical solution in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] The prestressed anchor cable support system is a commonly used active support structure with high tensile strength. At present, since there is no supporting active servo system and construction method for real-time monitoring and automatic tensioning of anchor cable prestressing, it seriously affects the anchor cable support system's ability to fully exert its deformation control ability and realize real-time monitoring and feedback of the anchor cable axial force, so as to replenish the prestressing in time. The present invention designs a prestressed anchor cable intelligent monitoring and tensioning system, which can realize real-time monitoring and feedback of the anchor cable axial force, and actively tension the prestress in time, which is conducive to giving full play to the deformation control advantages of the flexible support system, accurately guiding the foundation pit construction, and has the advantages of convenience, precision and high stability. Therefore, it has a good prospect for promotion and application.

[0036] Embodiment 1

[0037] See also Figures 1 to 6The embodiment of the present invention discloses an intelligent monitoring and tensioning system for a prestressed anchor cable 1, comprising an anchor plate 3, an active servo system, a first directional sliding anchor 5, and a second directional sliding anchor 6. The active servo system comprises an actuator, a displacement sensor 46, and a displacement hydraulic jack 4. The anchor plate 3, the first directional sliding anchor 5, the displacement hydraulic jack 4, and the second directional sliding anchor 6 are sequentially sleeved on the anchor cable 1. The anchor plate 3, the first directional sliding anchor 5, the displacement hydraulic jack 4, and the second directional sliding anchor 6 are all provided with a through hole for the anchor cable 1 to pass through. The anchor plate 3 is located between the anchoring pedestal 2 and the first directional sliding anchor 5. The hydraulic chamber of the displacement hydraulic jack 4 is connected to the actuator through a pipeline 12.

[0038] The displacement sensor 46 is used to monitor the change in the elongation of the anchor cable 1 in real time and transmit it to the data processing terminal 9. The data processing terminal 9 is used to determine the axial force of the anchor cable 1 according to the monitoring data of the displacement sensor 46, compare the axial force of the anchor cable 1 with the set prestress value, and output a control signal to the actuator according to the comparison result, so that the actuator can adjust the hydraulic pressure in the hydraulic cavity of the displacement hydraulic jack 4 according to the control signal, so that the sliding telescopic rod of the displacement hydraulic jack 4 transmits force to the anchor cable 1, thereby realizing active prestressing of the anchor cable 1.

[0039] The present invention can provide real-time feedback of oil pressure, temperature and axial strain of anchor cable 1 through pressure, temperature and displacement sensors 46 in actuators and hydraulic jacks; send real-time information to system data processing terminal 9 through wireless transmitter 10 to realize accurate monitoring of axial force of anchor cable 1; and transmit the signal of system data processing terminal 9 to actuator (power motor 8 of actuator) according to preset instructions, realize active prestressing of anchor cable 1 through transmission system; realize automatic anchoring of anchor cable 1 through unidirectional sliding fastening clips on anchor. The data acquisition terminal of the present invention analyzes and processes the received information to obtain the axial force of anchor cable 1, compares the axial force of anchor cable 1 with the set prestressing value, sends instructions to power motor 8, adjusts the pressure in hydraulic cavity, and performs prestressing of anchor cable 1; by analyzing the changes of axial force and elongation of anchor cable 1, the elastic fulcrum stiffness coefficient of anchor cable 1 system at any time can be determined. The change value of elongation of anchor cable 1, hydraulic oil temperature and pressure can be monitored in real time through displacement sensor 46, temperature sensor and pressure sensor, realizing real-time monitoring of axial force of anchor cable 1.

[0040] The construction method of the invention is novel in concept and easy to operate; the system has stable performance and can be recycled. The invention is not only conducive to giving full play to the deformation control advantage of the flexible support system, but also has good economic and technical benefits.

[0041] Further, the displacement hydraulic jack 4 includes a first cylinder body, which is provided with an annular through hole, which extends along the length direction of the anchor cable 1, and a first sliding telescopic rod 41 is provided at one end of the annular through hole of the first cylinder body. One end of the first sliding telescopic rod 41 extends out of the first cylinder body and abuts against the first directional sliding anchor 5, and the other end of the first sliding telescopic rod 41 is connected to a first sliding telescopic rod piston 44, which first sliding telescopic rod piston 44 slides in cooperation with the annular through hole of the first cylinder body, and a second sliding telescopic rod 42 is provided at the other end of the through hole of the first cylinder body, one end of the second sliding telescopic rod 42 extends out of the first cylinder body and abuts against the second directional sliding anchor 6, and the other end of the second sliding telescopic rod 42 is connected to a second sliding telescopic rod piston, which second sliding telescopic rod piston slides in cooperation with the annular through hole of the first cylinder body, and a first hydraulic chamber 43 is formed between the first sliding telescopic rod piston 44 and the second sliding telescopic rod piston.

[0042] Furthermore, the displacement sensor 46 is connected between the first sliding telescopic rod piston 44 and the second sliding telescopic rod piston.

[0043] Furthermore, the first directional sliding anchor 5 and the second directional sliding anchor 6 include an annular positioning sleeve 61 and a plurality of one-way fastening clips 62, wherein the annular positioning sleeve 61 is provided with a conical through hole 612, and the plurality of one-way fastening clips 62 are located in the annular positioning sleeve 61 and surround the outer periphery of the anchor cable 1, and the outer wall of the one-way fastening clip 62 is gap-matched with the through hole wall of the annular positioning sleeve 61.

[0044] The annular positioning sleeve 61 of the first directional sliding anchor 5 is provided with an annular positioning groove 611 for cooperating with the first sliding telescopic rod 41 .

[0045] The annular positioning sleeve 61 of the second directional sliding anchor 6 is provided with an annular positioning groove 611 for cooperating with the second sliding telescopic rod 42 .

[0046] In some embodiments, the first sliding telescopic rod 41 and the second sliding telescopic rod 42 are both hollow cylinders.

[0047] In some embodiments, the actuator includes a hydraulic cylinder 7. Further, the hydraulic cylinder 7 is a rotary jacking type hydraulic cylinder 7.

[0048] Furthermore, the hydraulic cylinder 7 includes a second cylinder body and a piston rod, one end of the piston rod extends out of the second cylinder body and is connected to the driving device, the other end of the piston rod is connected to one side of the piston 73, the piston 73 is slidably matched with the second cylinder body, and the other side of the piston and the second cylinder body form a second hydraulic chamber 74, and the second hydraulic chamber 74 of the actuator is connected to the first hydraulic chamber 43 of the displacement hydraulic jack 4 through a pipeline 12.

[0049] Furthermore, the driving device comprises a motor, a driving gear is arranged on the motor shaft of the motor, the piston rod is a threaded rod 71, a threaded transmission gear 72 is arranged on the threaded rod 71, and the transmission gear 72 is meshed with the driving gear.

[0050] The motor is connected to a data processing terminal 9, and the data processing terminal 9 is used to send a working instruction to the motor, and the motor is used to drive the hydraulic piston of the actuator to move.

[0051] A valve, i.e., an oil valve, is provided on the pipeline 12 or at both ends of the pipeline 12. A liquid hole is provided on the side wall of the first cylinder body, and the liquid hole of the first cylinder body is connected to the first hydraulic chamber 43 and one end of the pipeline 12. A liquid hole is provided on the side wall of the second cylinder body, and the liquid hole of the second cylinder body is connected to the second hydraulic chamber 74 and the other end of the pipeline 12.

[0052] In this embodiment, a jack hydraulic oil valve 47 is provided on the side wall of the first cylinder body, communicating with the fluid hole of the first cylinder body. A cylinder hydraulic oil valve 75 is provided on the side wall of the second cylinder body, communicating with the fluid hole of the second cylinder body.

[0053] Furthermore, a temperature and pressure sensor 11 is provided in the actuator, and the temperature sensor and the pressure sensor are connected to the wireless transmitter 10. The temperature sensor is used to monitor the temperature of the hydraulic pressure in the actuator in real time, and transmit it to the data processing terminal 9 through the wireless transmitter 10; the pressure sensor is used to monitor the hydraulic pressure in the actuator in real time, and transmit it to the data processing terminal 9 through the wireless transmitter 10.

[0054] The present invention provides a method for intelligent monitoring and tensioning of a prestressed anchor cable 1, comprising the following steps: receiving monitoring data collected by a sensor, analyzing and processing the received monitoring data to obtain the axial force of the anchor cable 1, and comparing the axial force of the anchor cable 1 with a set prestress value, and outputting a control signal to an actuator according to the comparison result, so that the actuator adjusts the hydraulic pressure in the hydraulic cavity of a displacement hydraulic jack 4 according to the control signal, so that the sliding telescopic rod of the displacement hydraulic jack 4 transmits force to the anchor cable 1, thereby realizing active tensioning of the prestressed anchor cable 1.

[0055] Furthermore, the method for intelligent monitoring and tensioning of the prestressed anchor cable 1 of the present invention also includes the following steps: sending instructions to the actuator to adjust the hydraulic pressure in the hydraulic cavity of the actuator and the displacement hydraulic jack, so that the pressure on the sliding telescopic rod on the displacement hydraulic jack 4 is consistent with the anchor rod anchoring prestress, so that the axial force of the anchor cable 1 is completely transmitted to the front anchoring platform through the sliding telescopic rod.

[0056] Furthermore, the method for intelligent monitoring and tensioning of the prestressed anchor cable 1 of the present invention further comprises the following steps: determining the elastic fulcrum stiffness coefficient of the anchor cable 1 system at any time by analyzing the changes in the axial force and elongation of the anchor cable 1, specifically comprising:

[0057] The displacement sensor 46 is used to obtain the deformation of the anchor cable 1 at any time, and the stiffness coefficient of the elastic support is calculated. The calculation formula is:

[0058] Δl=Δl F +Δl T

[0059] Δl T =α·l s ΔT

[0060] Then the stiffness coefficient k of the elastic support is expressed as:

[0061]

[0062] Where: A is the cross-sectional area of ​​the sliding telescopic rod of the displacement hydraulic sensor; P0 is the hydraulic pressure of the hydraulic chamber when the anchor cable is anchored; P1 is the hydraulic pressure of the hydraulic chamber during acquisition; Δl is the change in the elongation of the anchor cable; Δl F is the change in anchor cable elongation caused by the change in anchor cable axial force, and ΔF is the change in anchor cable axial force.

[0063] The present invention can push the sliding telescopic rod to tension the anchor cable 1 by adjusting the oil pressure in the first hydraulic chamber 43 of the displacement hydraulic jack 4, and the displacement sensor 46 can monitor the elongation change of the anchor cable 1 and truly reflect the micro-strain of the anchor cable 1.

[0064] The present invention drives the threaded rod 71 to push the piston to adjust the oil pressure in the second hydraulic chamber 74 of the actuator through the transmission gear 72. The temperature and pressure sensors can monitor the pressure and temperature of the hydraulic oil in real time, and feedback information to the data processing terminal 9 through the wireless data transmitter. The oil pressure can be transmitted to the first hydraulic chamber 43 of the displacement hydraulic jack 4 through the first oil valve, the oil pipe and the second oil pressure valve to adjust the sliding telescopic rod; the data processing terminal 9 can analyze the received data, obtain the real axial force value of the anchor cable 1, and send instructions to the power motor 8 to timely supplement the prestress of the anchor cable 1 to achieve active servo of the axial force of the anchor cable 1; the anchor hole of the directional sliding anchor allows the anchor cable 1 to pass through and anchor the anchor cable 1 through the unidirectional fastening clip 62; the anchor pad 3 can diffuse the system reaction force to the structural base to achieve balanced force of the system and avoid stress concentration.

[0065] The preferred solution is as follows Figure 1The data processing terminal 9 can receive feedback information from the wireless transmitter 10, process the information, determine the change of the anchor axial force, and send instructions to the power motor 8 to timely supplement the prestress of the anchor cable 1, so as to give full play to the deformation control ability of the active flexible support system on the structure.

[0066] The preferred solution is as follows Figure 1 The directional sliding anchor is provided with a one-way fastening clip 62. When the anchor is subjected to positive force, the one-way fastening clip 62 is in a relaxed state, and the anchor can slide freely along the anchor cable 1. When the anchor is subjected to reverse force, the one-way fastening clip 62 is in a taut state, and the displacement of the anchor is restricted, thereby realizing automatic anchoring of the anchor.

[0067] The preferred solution is as follows Figure 1 The displacement hydraulic jack 4 is provided with a displacement sensor 46, through which the elongation change of the anchor cable 1 can be monitored, the micro-strain of the anchor cable 1 can be truly reflected, the structural stiffness coefficient can be fed back in real time, and an accurate displacement-load change curve of the anchor cable 1 can be obtained.

[0068] The preferred solution is as follows Figure 1 The hydraulic cylinder 7 is provided with a temperature and pressure sensor, which can monitor the hydraulic oil pressure and temperature in the hydraulic cavity in real time. The hydraulic cylinder 7 can adjust the oil pressure in the hydraulic cavity of the hydraulic cylinder 7 through the threaded rod 71, the transmission gear 72 and the piston, thereby controlling the displacement of the hydraulic jack 4.

[0069] When the present invention is used, the anchor plate 3, the first directional sliding anchor 5, the displacement hydraulic jack 4 and the second directional sliding anchor 6 are sequentially passed through the anchor cable 1, and the relative positions of the various structures are adjusted so that the compression axis of the structure coincides with the anchor cable 1. Then, the power motor 8, the hydraulic cylinder 7 and the data processing terminal 9 are installed at a suitable position that does not hinder the construction, and the hydraulic chambers of the hydraulic cylinder 7 and the displacement hydraulic jack 4 are connected by an oil pipe; then, the anchor cable 1 is prestressed in stages, and when it is tensioned to the prestressed design value, the directional sliding anchor is anchored; after anchoring, the system is pressurized so that the axial force of the anchor cable 1 is completely transmitted by the sliding telescopic rod of the displacement hydraulic jack 4. After the above process is implemented, the above-mentioned active servo system can be used to intelligently monitor and supplement the axial force of the prestressed anchor cable 1, give full play to the system function, and guide the construction.

[0070] The system of the present invention (i.e., the active servo system of anchor cable 1) can have both monitoring and active tensioning functions. The system of the present invention is suitable for anchor cable 1 support systems in various slope projects such as roadbeds and foundation pits, and its purpose is to realize intelligent monitoring and active tensioning of the prestress of anchor cable 1. The system of the present invention can realize active tensioning of the prestress of anchor cable 1 by processing the information received by the data processing terminal 9 and sending instructions to the power motor 8. The data processing terminal 9 includes a wireless receiver, a data processing center and an instruction transmitter, which can realize real-time monitoring and active tensioning of the axial force of anchor cable 1.

[0071] Embodiment 2

[0072] The embodiment of the present invention also discloses a method for intelligent monitoring and tensioning of prestressed anchor cables, comprising the following steps:

[0073] S1: The data processing terminal 9 receives the monitoring data collected by the sensor, analyzes and processes the received monitoring data, obtains the axial force of the anchor cable 1, compares the axial force of the anchor cable 1 with the set prestress value, and outputs a control signal to the actuator according to the comparison result, so that the actuator can adjust the hydraulic pressure in the hydraulic cavity of the displacement hydraulic jack 4 according to the control signal, so that the sliding telescopic rod of the displacement hydraulic jack 4 transmits force to the anchor cable 1, thereby realizing active prestressing of the anchor cable 1.

[0074] The axial force of the anchor cable 1 is compared with the set prestress value, and a control signal is output to the actuator according to the comparison result, specifically including: comparing the axial force of the anchor cable 1 with the set prestress value to determine whether the axial force of the anchor cable 1 changes. If so, an instruction is sent to the actuator so that the actuator can adjust the hydraulic pressure in the hydraulic cavity of the displacement hydraulic jack 4 according to the control signal, so that the sliding telescopic rod of the displacement hydraulic jack 4 transmits force to the anchor cable 1, thereby realizing active prestressing of the anchor cable 1. If not, return to step S1.

[0075] The present invention compares the axial force of the anchor cable 1 with the set prestress value to determine the change in the axial force of the anchor cable 1, and judges whether to actively perform prestressing of the anchor cable 1, thereby realizing intelligent monitoring and prestressing of the anchor cable 1.

[0076] Furthermore, before step S1, the following step is also included: actively pressurizing the servo system.

[0077] The active servo system pressurization specifically includes: the data processing terminal 9 sends instructions to the actuator (such as the power motor 8 of one embodiment) to adjust the hydraulic pressure (such as hydraulic oil pressure) in the hydraulic cavity of the actuator and the displacement hydraulic jack, so that the pressure on the sliding telescopic rod on the displacement hydraulic jack 4 is consistent with the anchor rod anchoring prestress, so that the axial force of the anchor cable 1 is completely transmitted to the front anchoring platform through the sliding telescopic rod, and the sensor collects data and transmits it to the data processing terminal 9.

[0078] The sensors collect data and transmit it to the data processing terminal 9, specifically including: the displacement sensor 46 monitors the change of the elongation of the anchor cable 1 in real time, the temperature and pressure sensors monitor the temperature and pressure of the hydraulic oil in real time; the wireless transmitter 10 sends the monitoring data to the data processing terminal 9 at regular intervals.

[0079] The working principle of the active servo system of the present invention is as follows: the data processing terminal 9 sends a working instruction to the power motor 8, and the power motor 8 drives the hydraulic piston of the rotary jacking cylinder to move, thereby adjusting the oil pressure change in the hydraulic chamber; the force is transmitted to the anchor cable 1 through the sliding telescopic rod in the displacement hydraulic jack 4, thereby realizing the prestressing tensioning of the anchor cable 1; the displacement sensor 46, temperature sensor and pressure sensor can monitor the change value of the elongation of the anchor cable 1, the temperature and pressure of the hydraulic oil in real time, thereby realizing real-time monitoring of the axial force of the anchor cable 1.

[0080] The working principle of the data processing terminal 9 of the present invention is as follows: the information collected by the displacement, temperature and pressure sensors is transmitted to the data acquisition terminal through the wireless transmitter 10. The data acquisition terminal analyzes and processes the received information to obtain the axial force of the anchor cable, and compares the axial force of the anchor cable with the set prestress value, sends instructions to the power motor 8, adjusts the pressure in the hydraulic cavity, and supplements the prestress of the anchor cable; by analyzing the changes in the axial force and elongation of the anchor cable, the elastic fulcrum stiffness coefficient of the anchor cable system at any time can be determined.

[0081] The data processing calculation formula of the present invention is as follows:

[0082] Calculation of anchor cable axial force:

[0083] After the anchor cable is tensioned and anchored, the active servo system is pressurized. As the oil pressure in the hydraulic chamber gradually increases, the axial force of the anchor cable is gradually borne by the sliding telescopic rod in the displacement jack. When the sliding telescopic rod fully bears the axial force of the anchor cable, the anchor cable anchoring prestress F0 can be expressed as:

[0084] F0=A·P0 (1)

[0085] As the construction progresses, the anchor cable axial force F1 can be expressed as:

[0086] F1=A·P1 (2)

[0087] And the relationship between the two is:

[0088]

[0089] Change of anchor cable axial force:

[0090] ΔF=F0-F1=A·(P0-P1) (4)

[0091] When ΔF>0, the anchor cable prestressing needs to be supplemented and tensioned; when ΔF<0, the anchor cable prestressing is actively adjusted according to project needs.

[0092] By controlling the volume of the hydraulic chamber, the oil pressure can be controlled to achieve the above functions. The calculation method is as follows:

[0093]

[0094] Δl=ΔV / A (6)

[0095] The loading condition of the system can be precisely controlled by means of the displacement sensor 46 .

[0096] The displacement sensor 46 can be used to obtain the deformation of the anchor cable 1 at any time. According to the basic test calculation formula of the pull-out bearing capacity of the anchor cable 1, the stiffness coefficient of the elastic support can be determined. The calculation formula is as follows:

[0097] Δl=Δl F +Δl T (7)

[0098] The deformation of anchor cable 1 due to temperature change is Δl T , deformation Δl T It can be expressed as:

[0099] Δl T =α·l s ·ΔT (8)

[0100] Then the stiffness coefficient k of the elastic support can be expressed as:

[0101]

[0102] Where: F0—anchor cable 1 anchoring axial force (kN); A—cross-sectional area of ​​the sliding telescopic rod of the displacement hydraulic sensor (m 2 ); P0—hydraulic chamber oil pressure when anchor cable 1 is anchored (MPa); T0—temperature when anchor cable 1 is anchored (℃); V0—displacement hydraulic pressure when anchor cable 1 is anchored (volume of the first hydraulic chamber 43) (m 3 ); F1—axial force of anchor cable 1 during acquisition (kN); P1—oil pressure of hydraulic chamber during acquisition (MPa); T1—temperature during acquisition (℃); V1—volume of displacement hydraulic first hydraulic chamber 43 during acquisition (m 3 ) ; ΔF—change in the axial force of anchor cable 1 (kN); ΔV—change in the volume of the first hydraulic chamber 43 of the displacement hydraulic pressure during acquisition (m 3 ) ; Δl—elongation change of anchor cable 1 (mm); Δl F —Change in the elongation of the anchor cable 1 caused by the change in the axial force of the anchor cable 1 (mm); Δl T—Change in the elongation of the anchor cable 1 caused by temperature change (mm); α—Temperature linear expansion coefficient of the anchor cable 1; l s —free section length of anchor cable 1 (m); k—stiffness coefficient of anchor rod (kN / m).

[0103] Furthermore, before step S1, the following steps are also included:

[0104] Anchor cable 1 construction, anchor cap casting, active servo system assembly;

[0105] Installation of anchor cable 1 tensioning equipment;

[0106] Anchor cable 1 tensioning and anchoring construction: After the preliminary preparation work is completed, the anchor cable 1 tensioning construction can be carried out. Before the anchor cable 1 tensioning construction, first adjust the relative positions of the anchor pad 3, the directional sliding anchor and the displacement hydraulic jack 4 to ensure that the compression axis of the three coincides with the anchor cable 1 to avoid eccentric compression; after the adjustment is completed, pre-tensioning is carried out to make the components of each part in close contact, and then the formal tensioning construction is carried out. After the tensioning is completed, the rear end directional sliding anchor is anchored.

[0107] Furthermore, after step S1, the following steps are also included:

[0108] Recycling of the active servo system: After the construction is completed, when the prestress of the anchor cable 1 remains stable for a long time, the front-end directional sliding anchor can be anchored, and then the rear-end directional sliding anchor, displacement hydraulic jack 4 and other equipment can be removed and recycled in turn to realize the reuse of the active servo system. The construction process is shown in Figure 7.

[0109] The construction of anchor cable 1, pouring of anchor cap, and assembly of active servo system specifically include: configuring the required cement mortar according to the design, grouting reinforcement of anchor cable 1, and then pouring the anchor cap of anchor cable 1. When the concrete strength meets the tensioning requirements, the active servo system is installed.

[0110] The installation of the anchor cable 1 tensioning equipment specifically includes: passing the anchor plate 3, the displacement hydraulic jack 4, and the directional sliding anchor through the anchor cable 1 in sequence; placing the rotary jacking hydraulic cylinder 7 and the power motor 8 at the appropriate position of the base, and connecting the hydraulic cylinder 7 with the hydraulic cavity of the hydraulic jack with an oil pipe, and connecting the power motor 8 with the data processing terminal 9.

[0111] The present invention designs a system and method for intelligent monitoring and tensioning of prestressed anchor cable 1. The test system is intelligent, highly digitized, easy, fast and efficient to operate, and the construction method is novel. It can realize real-time transmission and active adjustment of prestress of anchor cable 1, which is conducive to giving full play to the deformation control advantage of flexible support system and accurately guiding foundation pit construction.

[0112] It is to be understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present disclosure, but the present disclosure is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and substance of the present disclosure, and these modifications and improvements are also considered to be within the scope of protection of the present disclosure.

Claims

1. A prestressed anchor cable intelligent monitoring and tensioning system, characterized in that: It includes an actuator, a displacement sensor, and an anchor plate, a first directional sliding anchor, a displacement hydraulic jack, and a second directional sliding anchor, which are sequentially sleeved on the anchor cable. The anchor plate, the first directional sliding anchor, the displacement hydraulic jack, and the second directional sliding anchor are all provided with a through hole for the anchor cable to pass through. The anchor plate is located between the anchoring pedestal and the first directional sliding anchor. The hydraulic chamber of the displacement hydraulic jack is connected to the actuator through a pipeline. The displacement sensor is used to monitor the change in the elongation of the anchor cable in real time and transmit it to the data processing terminal. The data processing terminal is used to determine the axial force of the anchor cable based on the monitoring data of the displacement sensor, compare the axial force of the anchor cable with the set prestress value, and output a control signal to the actuator based on the comparison result, so that the actuator can adjust the hydraulic pressure in the hydraulic cavity of the displacement hydraulic jack according to the control signal to achieve active tensioning of the anchor cable prestress.

2. The prestressed anchor cable intelligent monitoring and tensioning system according to claim 1 is characterized in that: The displacement hydraulic jack includes a first cylinder body, the first cylinder body is provided with an annular through hole, the annular through hole extends along the length direction of the anchor cable, a first sliding telescopic rod is provided at one end of the annular through hole of the first cylinder body, one end of the first sliding telescopic rod extends out of the first cylinder body and abuts against the first directional sliding anchor, the other end of the first sliding telescopic rod is connected to a first sliding telescopic rod piston, the first sliding telescopic rod piston slides with the annular through hole of the first cylinder body, a second sliding telescopic rod is provided at the other end of the through hole of the first cylinder body, one end of the second sliding telescopic rod extends out of the first cylinder body and abuts against the second directional sliding anchor, the other end of the second sliding telescopic rod is connected to a second sliding telescopic rod piston, the second sliding telescopic rod piston slides with the annular through hole of the first cylinder body, and a first hydraulic chamber is formed between the first sliding telescopic rod piston and the second sliding telescopic rod piston.

3. The prestressed anchor cable intelligent monitoring and tensioning system according to claim 2 is characterized in that: The displacement sensor is connected between the first sliding telescopic rod piston and the second sliding telescopic rod piston.

4. The prestressed anchor cable intelligent monitoring and tensioning system according to claim 1, 2 or 3, characterized in that: The first directional sliding anchor and the second directional sliding anchor include an annular positioning sleeve and a plurality of one-way fastening clips. The annular positioning sleeve is provided with a conical through hole. The plurality of one-way fastening clips are located in the annular positioning sleeve and surround the outer circumference of the anchor cable. The outer wall of the one-way fastening clip is gap-matched with the through hole wall of the annular positioning sleeve.

5. The prestressed anchor cable intelligent monitoring and tensioning system according to claim 1 is characterized in that: The actuator includes a second cylinder body and a piston rod, one end of the piston rod extends out of the second cylinder body and is connected to the driving device, the other end of the piston rod is connected to one side of the piston, the piston and the second cylinder body are slidably matched, and a second hydraulic chamber is formed between the other side of the piston and the second cylinder body. The second hydraulic chamber of the actuator is connected to the first hydraulic chamber of the displacement hydraulic jack through a pipeline.

6. The prestressed anchor cable intelligent monitoring and tensioning system according to claim 5 is characterized in that: The driving device comprises a motor, a motor shaft of which is provided with a driving gear, and the piston rod is a threaded rod, a threaded rod is provided with a transmission gear, and the transmission gear is meshed with the driving gear.

7. The prestressed anchor cable intelligent monitoring and tensioning system according to claim 1 is characterized in that: A temperature sensor and a pressure sensor are provided in the actuator, and the temperature sensor and the pressure sensor are connected to a wireless transmitter. The temperature sensor is used to monitor the temperature of the hydraulic pressure in the actuator in real time and transmit it to the data processing terminal through the wireless transmitter; the pressure sensor is used to monitor the hydraulic pressure in the actuator in real time and transmit it to the data processing terminal through the wireless transmitter.

8. A method for intelligent monitoring and tensioning of prestressed anchor cables, characterized in that: The steps include: The monitoring data collected by the sensor is received, and the received monitoring data is analyzed and processed to obtain the axial force of the anchor cable, and the axial force of the anchor cable is compared with the set prestress value. A control signal is output to the actuator according to the comparison result, so that the actuator can adjust the hydraulic pressure in the hydraulic cavity of the displacement hydraulic jack according to the control signal, so that the sliding telescopic rod of the displacement hydraulic jack transmits force to the anchor cable, thereby realizing active prestressing of the anchor cable.

9. The method for intelligent monitoring and tensioning of prestressed anchor cables according to claim 8, characterized in that: It also includes the following steps: sending instructions to the actuator to adjust the hydraulic pressure in the hydraulic cavity of the actuator and the displacement hydraulic jack, so that the pressure on the sliding telescopic rod on the displacement hydraulic jack is consistent with the anchor rod anchoring prestress, so that the axial force of the anchor cable is completely transmitted to the front anchoring platform through the sliding telescopic rod.

10. The method for intelligent monitoring and tensioning of prestressed anchor cables according to claim 8, characterized in that: The method also includes the following steps: determining the elastic support stiffness coefficient of the anchor cable system at any time by analyzing the changes in the axial force and elongation of the anchor cable, specifically including: The displacement sensor is used to obtain the deformation of the anchor cable at any time and calculate the stiffness coefficient of the elastic support. The calculation formula is: Δl=Δl F +Δl T Δl T =α·l s ·ΔT Then the stiffness coefficient k of the elastic support is expressed as: Where: A is the cross-sectional area of ​​the sliding telescopic rod of the displacement hydraulic sensor; P0 is the hydraulic pressure of the hydraulic chamber when the anchor cable is anchored; P1 is the hydraulic pressure of the hydraulic chamber during acquisition; Δl is the change in the elongation of the anchor cable; Δl F is the change in anchor cable elongation caused by the change in anchor cable axial force, and ΔF is the change in anchor cable axial force.

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