CN111794222A - An intelligent bolt controlled by hydraulic servo system - Google Patents

Abstract

An intelligent anchor rod controlled by a hydraulic servo system comprises an anchor rod body, a loading device positioned at one end of the anchor rod body and a miniature fiber bragg grating strain sensor stuck on the anchor rod body; the anchor rod body comprises a plurality of parallel steel strands; the loading device comprises an outer ring structure and an inner ring structure, the outer ring structure adopts a large-scale through type hydraulic jack structure, and the outer end of a piston of the outer ring structure is provided with the inner ring structure; the inner ring structure is a disc type structural member, a plurality of through holes are formed in the disc type structural member along the circumferential direction of the disc type structural member, and an anchoring structure is fixedly arranged in each through hole; the anchoring structure adopts a small-sized through hydraulic jack structure, a single-hole tool anchor is installed at the front end of a piston rod of the anchoring structure, an anchoring hole is formed in the center of the single-hole tool anchor, and a steel strand is anchored in the anchoring hole; the hydraulic servo system drives and connects the outer ring structure and the anchoring structure. The invention can monitor and control the stress condition in the anchor rod in real time, reduce the maintenance difficulty in the operation stage of the anchor rod and ensure the stability of the supporting structure.

Description

An intelligent bolt controlled by hydraulic servo system

technical field

The invention relates to the field of engineering monitoring, in particular to an intelligent anchor rod controlled by a hydraulic servo system.

Background technique

As a supporting structure that can actively improve the strength and self-stabilizing ability of the rock and soil mass, the bolt is widely used in construction, water conservancy, electric power, mine roadway, and slope reinforcement due to its advantages of low cost, simple construction and short construction period. and foundation pit support. With the expansion of bolt application fields, engineers found a series of problems during use. For example, in foundation pit engineering, multiple anchors are generally applied. When the excavation reaches the design depth, additional anchors will be added, and then the excavation will continue downwards, and a second anchor will be added, and so on, until the foundation pit excavation is completed. With the excavation process, the working face of the first few bolts will disappear. If the support structure has a large displacement deformation in the later stage, the deformation can be quickly and effectively controlled by adjusting the force of several anchor rods around the large deformation of the support structure. However, the disappearance of the working face of the bolt makes it difficult to adjust the force of the bolt. The construction unit generally adopts other methods to reinforce the supporting structure, which is time-consuming and labor-intensive, and cannot be controlled immediately. If the horizontal displacement of the supporting structure is not controlled in time, it may cause safety accidents. In addition, the use of anchors always has the problem of loss of prestress. Only when the prestress of the anchor rod meets certain requirements, it can be called active support. Once the prestress of the anchor rod fails to meet the requirements, it will greatly affect the effect of active support and cause potential safety hazards.

How to realize the real-time monitoring of the stress and loss state of the bolt and ensure the long-term safety and stability of the geotechnical anchoring project is also the key to the development of geotechnical anchoring technology. At this stage, the test methods for the stress and damage state of anchors at home and abroad mainly include two categories: one is based on the reflection difference detection of electromagnetic waves and sound waves in different medium layers; Rod pull gauge, differential resistance strain gauge and resistance strain gauge directly test the stress and damage state of the bolt under the action of pulling. However, these test methods have shortcomings such as being susceptible to interference, large test errors, poor durability, and poor long-term stability, which make it difficult to meet the long-term stable monitoring needs of geotechnical anchoring projects in hidden, wet, and rusted environments. In addition, the number of anchor rods applied to a certain project is tens of thousands, and the number is huge, which makes it difficult to take into account all anchor rods in actual monitoring.

In recent years, IoT technology has been continuously applied to various fields. And new technologies such as optical fiber and grating sensing technology are also developing rapidly, which provides new ideas and new tools for engineering monitoring work. Aiming at the disadvantages of the existing bolt anchoring system that has high detection cost and cannot meet long-term monitoring requirements, the present invention proposes an intelligent bolt controlled by the hydraulic servo system in combination with the hydraulic servo system. The bolt can receive miniature fiber gratings in real time. Strain sensor data is automatically processed and analyzed, and according to the real-time data, the stress of the anchor is controlled by the system, so as to ensure the safety of the structure.

SUMMARY OF THE INVENTION

To overcome the above problems, the present invention provides an intelligent anchor rod controlled by a hydraulic servo system.

The technical scheme adopted in the present invention is: an intelligent bolt controlled by a hydraulic servo system, comprising a bolt body, a loading device located at one end of the bolt body, and a miniature fiber grating strain sensor pasted on the bolt body;

The bolt body is divided into an anchoring section and a free section. The bolt body includes a plurality of steel strands that are parallel to each other. The steel strands pass through the loading device and are fixed in the anchoring holes of the loading device; the outer surface of the steel strands A microfiber grating strain sensor is pasted along its axial interval; the microfibre The controller, the controller is connected with the hydraulic servo system signal;

The loading device includes an outer ring structure and an inner ring structure, the outer ring structure is fixed on the waist beam by bolts; the outer ring structure adopts a large through-core hydraulic jack structure, and an inner ring structure is installed on the outer end of the piston of the outer ring structure; The ring structure is a disc-type structural member. The disc-shaped structural member is provided with a number of through holes along its circumferential direction, and an anchoring structure is fixedly installed in the through-hole; the anchoring structure adopts a small through-core hydraulic jack structure. A single-hole tool anchor is installed at the front end of the piston rod, an anchoring hole is arranged at the center of the single-hole tool anchor, and a steel strand is anchored in the anchoring hole; the hydraulic servo system drives the connection between the outer ring structure and the anchoring structure.

Further, the arrangement density of the micro-fiber grating strain sensors on the anchored segment is greater than the arrangement density of the micro-fiber grating strain sensors on the free segment.

Further, the controller is electrically connected to the alarm, and when the data collected by the micro-fiber grating strain sensor is lower than the preset threshold, the controller triggers the alarm to turn on.

Further, the controller is connected with a remote terminal through wireless communication, and the remote terminal is a computer, a mobile phone or a tablet computer.

Further, a protective cover is installed outside the loading device.

Further, a plastic tube is sleeved on the outside of the steel strand and the micro fiber grating sensor.

The beneficial effects of the present invention are:

1) It can reduce the maintenance difficulty in the operation stage of the bolt, improve the detection efficiency of the bolt in the operation stage, and compared with the strain gauge, the grating has a longer life, and can be used for long-term monitoring through the reserved port during the operation of the bolt;

2) The hydraulic servo system is used to control the stress of the anchor rod in real time, so that the prestress value of the anchor rod can be kept at a fixed value, and the stress of the anchor rod can be adjusted according to the real-time data to ensure the stability of the supporting structure;

3) The anchors in multiple positions of the supporting structure can be monitored at the same time, and intelligent anchors can be implanted in multiple positions according to the monitoring requirements to realize the overall monitoring of an area.

Description of drawings

Figure 1 is a schematic structural diagram of the present invention.

FIG. 2 is a schematic diagram of the structure of the loading device.

Description of reference numerals: 1-protective cover, 2-loading device, 3-steel strand, 4-miniature fiber grating strain sensor, 5-hole, 6-data transmission line, 7-outer ring structure, 8-inner ring structure, 9-Anchor hole, 10-Hydraulic servo system.

Detailed ways

The technical solutions of the patent of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that when the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" appear. The orientation or positional relationship indicated by ” and the like is based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, a specific orientation, and a specific orientation. The orientation configuration and operation of the device should not be construed as a limitation of the present invention. Furthermore, the terms "first," "second," and "third," as they appear, are for descriptive purposes only and should not be construed to indicate or imply relative importance.

In the description of the present invention, it should be noted that, unless otherwise expressly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it may be a fixed connection or a Removable connection, or integral connection; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through an intermediate medium, can be internal communication between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in specific situations.

Referring to the accompanying drawings, an intelligent anchor rod controlled by a hydraulic servo system includes an anchor rod body, a loading device located at one end of the anchor rod body, and a miniature fiber grating strain sensor attached to the anchor rod body;

The bolt body is divided into an anchoring section and a free section. The bolt body includes a plurality of steel strands 3 parallel to each other. The steel strands 3 pass through the loading device 2 and are fixed in the anchoring hole of the loading device 2; The outer surface of the wire 3 is pasted with micro-fiber grating strain sensors 4 at intervals along its axial direction. The micro-fiber grating strain sensors 4 are used to detect the bearing capacity and stress and strain of the steel strand 3; the number and density of the micro-fiber grating strain sensors 4 can be adjusted. According to the actual adjustment of the project, it can be properly encrypted at the anchoring section. The micro-fiber grating strain sensor 4 is signal-connected to the controller to transmit the detection data to the controller, and the controller is signal-connected to the hydraulic servo system 10; It can slow down the corrosion of steel strands and ensure the survival rate of micro fiber grating strain sensors.

The loading device 2 includes an outer ring structure 7 and an inner ring structure 8, the outer ring structure 7 is fixed on the waist beam by bolts, and a protective cover is installed on the outside of the outer ring structure 7; the outer ring structure 7 adopts a large through-core hydraulic jack The inner ring structure 8 is installed on the outer end of the piston of the outer ring structure 7; the inner ring structure 8 is a disc-shaped structural member, and the disc-shaped structural member is provided with a number of through holes along its circumferential direction, and the number of through holes is customized according to the design. , An anchoring structure is fixedly installed in the through hole; the anchoring structure adopts a small through-core hydraulic jack structure, a single-hole tool anchor is installed at the front end of the piston rod of the anchoring structure, and an anchoring hole is arranged at the center of the single-hole tool anchor. 9. A steel strand 3 is anchored in each anchoring hole 9; the hydraulic servo system 10 drives and connects the outer ring structure and the anchoring structure.

The controller is electrically connected with the alarm, and when the data collected by the micro fiber grating strain sensor is lower than the preset threshold, the controller triggers the alarm to turn on. The controller is connected with a remote terminal through wireless communication, and the remote terminal is a computer, a mobile phone or a tablet computer.

Anchor rod construction: Put the completed anchor rod into the pre-drilled hole 5, install the loading device 2 and the protective cover 1 in order from the inside to the outside, and ensure that each steel strand 3 passes through an anchor hole 9. Before grouting, test whether the micro fiber grating strain sensor 4, data transmission line 6 and hydraulic servo system work normally. After the grouting is completed, the bolt tensioning work can be carried out. When prestressing is applied, considering that the range of the loading device involved in the present invention is small, conventional hydraulic jacks can be used to stretch to the design value first, and then the loading device 2 is used to lock the steel strand 3 .

Anchor operation: The monitoring data of the supporting structure is fed back to the controller through the fiber grating strain sensor 4 and other monitoring equipment. The controller conducts preliminary analysis according to the preset settings. If a certain monitoring data exceeds the threshold, the controller will automatically give an alarm and report danger. In addition, the operator can adjust the force of the anchor rod in real time through the loading device 2 according to the actual situation. For example, when the bolt is tensioned, the stress of a single steel strand 3 may be uneven, and the stress of a single steel strand 3 is too large or too small, which will affect the overall stress of the anchor. At this time, the controller can send an instruction to the hydraulic servo system 10, and the anchoring structure can be used to hydraulically adjust the force of the single steel strand 3. For another example, if the prestress loss of the anchor rod is too large, and the prestress of the entire anchor rod needs to be adjusted, the outer ring structure of the loading device is used to hydraulically adjust the entire anchor rod. In addition, the controller can control multiple anchor rods in one area at the same time, and adjust the anchor rods in the whole area at the same time, so as to achieve the overall control of the supporting structure.

The content described in the embodiments of the present specification is only an enumeration of the realization forms of the inventive concept, and the protection scope of the present invention should not be regarded as limited to the specific forms stated in the embodiments, and the protection scope of the present invention also extends to those skilled in the art. Equivalent technical means that can be conceived by a person based on the inventive concept.

Claims (5)

1. The utility model provides an intelligent stock by hydraulic servo control which characterized in that: the anchor rod comprises an anchor rod body, a loading device positioned at one end of the anchor rod body and a miniature fiber bragg grating strain sensor adhered to the anchor rod body;

the anchor rod body is divided into an anchoring section and a free section, the anchor rod body comprises a plurality of parallel steel strands, and the steel strands penetrate through the loading device and are fixed in anchoring holes of the loading device; miniature fiber bragg grating strain sensors are stuck on the outer surface of the steel strand at intervals along the axial direction of the steel strand, and the miniature fiber bragg grating strain sensors are used for monitoring the bearing capacity of the anchor rod and the stress strain of the steel strand; the micro fiber bragg grating strain sensor is in signal connection with the controller, detection data are transmitted to the controller, and the controller is in signal connection with the hydraulic servo system;

the loading device comprises an outer ring structure and an inner ring structure, and the outer ring structure is fixed on the waist rail through bolts; the outer ring structure adopts a large-scale feed-through hydraulic jack structure, and the outer end of a piston of the outer ring structure is provided with an inner ring structure; the inner ring structure is a disc type structural member, a plurality of through holes are formed in the disc type structural member along the circumferential direction of the disc type structural member, and an anchoring structure is fixedly arranged in each through hole; the anchoring structure adopts a small-sized through hydraulic jack structure, a single-hole tool anchor is installed at the front end of a piston rod of the anchoring structure, an anchoring hole is formed in the center of the single-hole tool anchor, and a steel strand is anchored in the anchoring hole; the hydraulic servo system drives and connects the outer ring structure and the anchoring structure.

2. An intelligent anchor rod controlled by a hydraulic servo system as claimed in claim 1, wherein: the arrangement density of the micro fiber bragg grating strain sensors on the anchoring section is greater than that of the micro fiber bragg grating strain sensors on the free section.

3. An intelligent anchor rod controlled by a hydraulic servo system as claimed in claim 1, wherein: the controller is electrically connected with the alarm, and when the data collected by the miniature fiber grating strain sensor is lower than a preset threshold value, the controller triggers the alarm to be started.

4. An intelligent anchor rod controlled by a hydraulic servo system as claimed in claim 1, wherein: the controller is connected with a remote terminal in a wireless communication mode, and the remote terminal is a computer, a mobile phone or a tablet computer.

5. An intelligent anchor rod controlled by a hydraulic servo system as claimed in claim 1, wherein: and plastic pipes are sleeved outside the steel strand and the miniature fiber grating sensor.

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