CN-121976830-A - Anchor rod active prestress release system for controlling stability of deep surrounding rock

CN121976830ACN 121976830 ACN121976830 ACN 121976830ACN-121976830-A

Abstract

The invention relates to the technical field of underground engineering support, and discloses an active prestress release system for an anchor rod for controlling stability of deep surrounding rock. One end of the anchor rod body is anchored at the bottom of a preset drilling hole of the deep surrounding rock, the other end of the anchor rod body extends to the outside of the drilling hole, and the prestress application assembly is sleeved at one end of the anchor rod body extending to the outside of the drilling hole and used for applying initial prestress to the anchor rod body. The surrounding rock stress and displacement data are acquired in real time through the surrounding rock state monitoring component, the central control unit automatically judges and drives the prestress to execute the action of the release component according to the preset threshold value, and the limitation that the traditional anchor rod cannot be adjusted according to the dynamic change of the surrounding rock after the prestress is applied is broken. The stress redistribution of deep surrounding rock due to excavation disturbance can be timely adapted.

Inventors

LIANG DONGXU
ZHANG NONG
PAN DONGJIANG
HUANG PENGCHENG

Assignees

深地科学与工程云龙湖实验室
徐州工程学院

Dates

Publication Date: 20260505
Application Date: 20251231

Claims (9)

1. An active prestress release system for an anchor rod for controlling stability of deep surrounding rock is characterized by comprising an anchor rod body, a prestress application component, a surrounding rock state monitoring component, a prestress execution release component and a central control unit; the pre-stressing assembly is sleeved at one end of the anchor rod body extending to the outside of the drilling hole and is used for applying initial pre-stressing force to the anchor rod body; The surrounding rock state monitoring assembly is arranged in the surrounding rock at the periphery of the anchor rod body and on the wall of the borehole and is used for collecting stress value and displacement data of the surrounding rock; the prestress execution release assembly is connected in series between the anchor rod body and the prestress application assembly and is electrically connected with the central control unit; The central control unit receives data transmitted by the surrounding rock state monitoring assembly, when the monitored surrounding rock stress value exceeds a preset stress threshold value or the surrounding rock displacement exceeds a preset displacement threshold value, the central control unit sends a control signal to the prestress execution release assembly to drive the prestress execution release assembly to act, the prestress of the anchor rod body is quantitatively released, and the released prestress value is regulated through preset parameters of the central control unit.
2. The active pre-stress release system for the anchor rod for controlling stability of deep surrounding rock is characterized in that the surrounding rock state monitoring assembly comprises a stress sensor and a displacement sensor, wherein the stress sensor is buried in surrounding rock around an anchor rod body, at least two stress sensors are arranged at intervals along the depth direction of a drilling hole and used for collecting surrounding rock stress data at different depths, the displacement sensor is arranged between the wall of the drilling hole and the anchor rod body, at least two stress sensors are arranged at intervals along the axial direction of the anchor rod body and used for collecting displacement data of surrounding rock at different axial positions relative to the anchor rod body, the stress sensor and the displacement sensor are electrically connected with a central control unit through a data transmission line, and an anti-corrosion wear-resistant sleeve is wrapped outside the data transmission line.
3. The anchor rod driving prestress release system for controlling stability of deep surrounding rock is characterized by comprising a driving module, a transmission module and a locking module, wherein the driving module comprises a hydraulic cylinder and an electromagnetic driver, a cylinder body of the hydraulic cylinder is fixedly connected with the prestress application module, a piston rod of the hydraulic cylinder is connected with the locking module through the transmission module, the electromagnetic driver is electrically connected with a central control unit and used for controlling on-off of an oil way of the hydraulic cylinder and oil quantity, the transmission module is a gear transmission mechanism and comprises a driving gear and a driven gear, the driving gear is fixedly connected with a piston rod of the hydraulic cylinder, the driven gear is connected with the locking module, the locking module is sleeved on the outer side of an anchor rod body, an inner wall of the locking module is provided with an inner thread matched with the outer thread of the anchor rod body, and the driven gear drives the locking module to move along the axial direction of the anchor rod body when rotating so as to realize prestress release.
4. The active pre-stress release system for the anchor rod for controlling the stability of deep surrounding rock according to claim 1 is characterized in that the central control unit comprises a data processing module, a threshold comparison module, a control instruction generation module and a parameter storage module, wherein the data processing module receives raw data transmitted by a surrounding rock state monitoring component, filters and reduces noise, and transmits the raw data to the threshold comparison module, the threshold comparison module compares the processed data with a stress threshold and a displacement threshold preset in the parameter storage module, when the data exceeds the corresponding threshold, a trigger signal is sent to the control instruction generation module, the control instruction generation module generates a pre-stress release control instruction according to the trigger signal and a release amount parameter preset in the parameter storage module and sends the pre-stress release control instruction to a pre-stress execution release component, and the parameter storage module can modify and update the threshold parameter and the release amount parameter through an external terminal.
5. The active pre-stress release system for the anchor rod for controlling stability of deep surrounding rock according to claim 1, wherein the pre-stress applying component comprises a pre-tightening nut, a gasket and a pre-tightening driving piece, the pre-tightening nut is in threaded connection with one end of an anchor rod body extending to the outside of a drill hole, the gasket is arranged between the pre-tightening nut and the pre-stress executing and releasing component, the pre-tightening driving piece is a torque wrench, the output end of the torque wrench is clamped with the pre-tightening nut and is used for applying set torque to the pre-tightening nut to enable the anchor rod body to obtain initial pre-stress, and a torque sensor is arranged on the outer side of the pre-tightening nut and is electrically connected with a central control unit and used for monitoring the torque value of the pre-tightening nut in real time and feeding back the torque value to the central control unit.
6. The active pre-stress release system for the anchor rod for controlling the stability of deep surrounding rock according to claim 1, further comprising a safety protection component, wherein the safety protection component comprises a pressure relay and a displacement limit switch, the pressure relay is arranged in a hydraulic oil path of the pre-stress execution release component and is electrically connected with a central control unit, the pressure relay sends a stop signal to the central control unit when the pressure of the oil path exceeds a preset safety pressure, the displacement limit switch is arranged at one end of an anchor rod body extending to the outside of a drill hole and is electrically connected with the central control unit, and when a locking module of the pre-stress execution release component moves to a position of the displacement limit switch, the displacement limit switch sends a stop signal to the central control unit to prevent the pre-stress from being excessively released.
7. The active prestress release system for deep surrounding rock stability control according to claim 1, wherein the prestress execution release assembly further comprises a displacement encoder, the displacement encoder is arranged on a driven gear shaft of the transmission module, is electrically connected with the central control unit, is used for monitoring the rotation angle of the driven gear in real time, converting angle data into axial displacement data of the locking module, and feeding back the axial displacement data to the central control unit to realize closed-loop control of the prestress release amount.
8. The active prestress release system for deep surrounding rock stability control according to claim 1, wherein the prestress execution release assembly further comprises a displacement encoder, the displacement encoder is arranged on a driven gear shaft of the transmission module, is electrically connected with the central control unit, is used for monitoring the rotation angle of the driven gear in real time, converting angle data into axial displacement data of the locking module, and feeding back the axial displacement data to the central control unit to realize closed-loop control of the prestress release amount.
9. The active pre-stress release system for the anchor rod for controlling the stability of deep surrounding rock according to claim 1, wherein the pre-stress applying assembly further comprises an energy accumulator, the energy accumulator is communicated with a hydraulic cylinder oil way of the pre-stress executing and releasing assembly and is used for storing the pressure energy of hydraulic oil, and when the pre-stress executing and releasing assembly completes one pre-stress release, the energy accumulator supplements the hydraulic oil for the hydraulic cylinder, provides power for the next pre-stress release and reduces the continuous energy supply requirement of an external hydraulic source.

Description

Anchor rod active prestress release system for controlling stability of deep surrounding rock Technical Field The invention relates to the technical field of underground engineering support, in particular to an active prestress release system for an anchor rod for controlling stability of deep surrounding rock. Background In the engineering fields of deep mining of mineral resources, construction of deep-buried tunnels and the like, the deep surrounding rock is easy to generate stress redistribution after excavation disturbance due to high initial ground stress, and instability risks such as surrounding rock deformation, crack expansion and even collapse are accompanied, so that the stability control of the surrounding rock becomes a core requirement for guaranteeing engineering safety, the main control means in the industry at present are anchor bolt support technology which restricts surrounding rock deformation by applying prestress to an anchor bolt body and utilizing the anchoring effect of the anchor bolt and the surrounding rock, wherein an active prestress anchor bolt has the advantage of being capable of applying prestress in advance and actively restraining early deformation of the surrounding rock compared with the traditional passive anchor bolt in stability control effect, and the active prestress anchor bolt gradually replaces the passive anchor bolt to become a main support form of the deep engineering. However, the existing active pre-stressing anchor rod technology still has significant limitations that firstly, the pre-stressing of the existing active pre-stressing anchor rod is set and applied at one time in the construction stage, the follow-up pre-stressing cannot be adjusted according to dynamic changes of surrounding rocks, the deep surrounding rocks can continuously change stress states and deformation characteristics due to factors such as excavation unloading, lithology difference, time effect and the like in the engineering advancing process, the fixed pre-stressing is easy to have two problems, namely when the stress of the surrounding rocks continuously rises, the fixed pre-stressing can be released to cause overload breaking of the anchor rod body and lose supporting effect, and when the deformation of the surrounding rocks exceeds the constraint range of the pre-stressing, the fixed pre-stressing cannot effectively inhibit the surrounding rocks from further deformation due to deficiency, and finally instability is caused. Secondly, although some prior art attempts to adjust prestressing force through manual mode, for example adopts torque wrench secondary to screw up or loosen the nut, but manual adjustment need rely on the staff to get into deep dangerous operation region, and not only response speed is slow, can't deal with the surrounding rock burst deformation in real time, and the adjustment volume relies on manual experience to judge completely, lacks accurate control basis, easily leads to prestressing force release excessive or not enough, aggravates the surrounding rock stability risk on the contrary. In addition, the existing few anchor rod systems with monitoring functions only can realize the collection and display of surrounding rock stress and displacement data, the monitoring data and the prestress adjustment process are mutually independent, the data analysis and regulation operation are needed to be completed through manual intervention, the regulation hysteresis is existed, the real-time, precision and safety requirements on stability control under the conditions of deep surrounding rock dynamic, complex and high risk are difficult to meet, therefore, an active control system with a safety protection mechanism, capable of automatically and precisely adjusting the anchor rod prestress based on the real-time state of the surrounding rock, becomes a key direction for solving the stability control problem of the current deep surrounding rock, is developed. Disclosure of Invention Aiming at the defects of the prior art, the invention provides an active prestress release system for an anchor rod for controlling the stability of deep surrounding rock, which solves the problems in the background art. The invention is realized by the following technical scheme that the active prestress release system for the anchor rod for controlling the stability of deep surrounding rock comprises an anchor rod body, a prestress applying component, a surrounding rock state monitoring component, a prestress executing and releasing component and a central control unit; the pre-stressing assembly is sleeved at one end of the anchor rod body extending to the outside of the drilling hole and is used for applying initial pre-stressing force to the anchor rod body; The surrounding rock state monitoring assembly is arranged in the surrounding rock at the periphery of the anchor rod body and on the wall of the borehole and is used for collecting stress value and displacement data of the surr