CN102877870A - Static and dynamic combined intelligent pre-warning anchor rod - Google Patents

Abstract

The invention relates to a dynamic and static combination intelligent early warning bolt, which is formed by connecting a hollow grouting rod body (1) and a solid rod body (3) through a casing (2), and is bonded and anchored with the surrounding rock of the hole wall, and the casing ( 2) If the bag is not bonded to the surrounding rock of the hole wall, the solid rod section (3) can pass through the large inner diameter section of the casing (2), but part of the shaft cannot pass through the small inner diameter of the casing (2) section, a displacement sensor (10) is fixed inside the sleeve, and the displacement sensor (10) is connected to the intelligent early warning device (12) outside the anchor hole through the communication line (11) passing through the hollow grouting rod body (1) , the displacement sensor (10) can be a mechanical wheel, an ultrasonic range finder or an infrared range finder, etc. The invention adds intelligent measurement and early warning functions on the basis of the original dynamic and static combined bolt, which can realize continuous and reliable support, safety monitoring and early warning in the field of surrounding rock dynamic disaster monitoring and prevention, and is suitable for market promotion and use.

Description

Dynamic and static combination intelligent early warning bolt

technical field

The invention relates to a support and real-time monitoring and early warning equipment for hard and brittle surrounding rock caverns, in particular to a dynamic and static combined anchor rod with early warning function for preventing and controlling dynamic disasters in surrounding rock, belonging to the field of geotechnical engineering anchoring.

Background technique

Surrounding rock dynamic disaster is a complex safety problem in underground rock mass engineering in deep working environment. It is a dynamic instability failure induced by certain factors after excavation and unloading of hard and brittle surrounding rock with complete structure in high ground stress environment. The dynamic characteristics of the sudden and violent ejection, throwing, ejection and flaking of the cave wall to the excavation space have the characteristics of hysteresis, continuity, suddenness, violence and hazards, which seriously threaten the underground Safety of structures, personnel and equipment. Rockburst, mine rockburst and other surrounding rock dynamic disasters become more and more serious with the increase of mining depth.

The early warning and prevention of surrounding rock dynamic disasters can ensure the safe mining of deep mineral resources and the construction process of underground projects such as tunnels. When dynamic disasters such as rockburst occur in hard and brittle surrounding rock caverns, the dynamic stress is very large, which generally reaches or exceeds the yield strength of the supporting components. If the supporting system does not have yielding and yielding properties, damage will inevitably occur. At the same time, due to the hard and compact characteristics of the hard and brittle surrounding rock itself, the causes of its failure involve the categories of rock dynamics and rock statics. The bolt can effectively control the self-bearing capacity of the surrounding rock, so the hard and brittle surrounding rock support system also uses an extensible bolt to provide a certain deformation to accommodate the forced large deformation caused by the dynamic failure of the surrounding rock. In response to rockburst, rock burst and other surrounding rock dynamic disasters, some rockburst-resistant extensible bolts have been proposed. Patent No. 201020684957.X discloses a water-swellable elastic rockburst-resistant bolt, but the water-swellable The bearing capacity of the bolt is low, and it is not suitable for high ground stress. At the same time, the rigid spring is only an improvement on the extension of the surface of the roadway, and the deformation ability under the full-length anchorage is very weak. Patent No. 201110332493.5 discloses a welded dynamic and static combination bolt, which can adapt to the static and dynamic failure characteristics of hard and brittle surrounding rock, but has a single structure and function, and only has the function of yielding support, but does not have the function of early warning.

The prediction and early warning of surrounding rock dynamic disasters such as rockburst and rock burst is to determine the location, time, and degree of danger of the disaster. Field measurement methods are often used in advance prediction of surrounding rock dynamic disasters, mainly including drilling cuttings method, electromagnetic radiation method, acoustic emission, and microseismic wave prediction methods. The outstanding disadvantages of the drilling cuttings method are the danger of the operator during the implementation process, the operational errors that vary from person to person, and the inability to continuously monitor, resulting in the omission of useful information and false positives. Acoustic emission (microseismic) monitoring method requires drilling to install monitoring probes, which will cause further damage and impact on the surrounding rock. The installation and monitoring process is relatively cumbersome and expensive. The quality requirements are high, and blasting and mechanical equipment also interfere with the monitoring results. The above two methods cannot realize non-destructive real-time monitoring and early warning of rockburst in surrounding rock. For this reason, Patent No. 01272808.X discloses a coal-rock dynamic disaster electromagnetic radiation monitoring device, which can realize non-destructive (non-contact) and positioning monitoring, but due to the complexity of groundwater and electromagnetic environments in some mines, the monitoring results are relatively limited. A large impact will lead to large errors in the monitoring results. Patent No. 201110109285.9 discloses a method for non-destructive real-time magnetic monitoring and prediction of rockburst in deep surrounding rocks, but the prediction accuracy of this method is unconvincing in the absence of theoretical and experimental research. Therefore, there is an urgent need for a monitoring method and device capable of continuous, reliable support, safety monitoring, and early warning in the field of monitoring and prevention of surrounding rock dynamic disasters.

Contents of the invention

In order to solve the above problems, the problem to be solved by the present invention is to provide an intelligent rock bolt capable of monitoring and early warning of dynamic disasters in surrounding rocks and adapting to the static and dynamic failure characteristics of hard and brittle surrounding rocks. The design scheme of the present invention is as follows: a dynamic and static combination intelligent early warning bolt is formed by a hollow grouting rod body and a solid rod body connected by a casing, and a tray and a nut are provided on the hollow grouting rod body, wherein: the hollow grouting rod body The slurry rod body and the solid rod body are bonded and anchored to the surrounding rock of the hole wall; the casing includes a large inner diameter section and a small inner diameter section, which are not bonded to the surrounding rock of the hole wall; the solid rod body section can pass through the casing large inner diameter section, but part of the shaft cannot pass through the small inner diameter section of the casing; the casing is arranged near the boundary of the fracture softening zone and elastic zone inside the surrounding rock, between the hollow grouting A displacement sensor is fixed in the casing between the rod bodies, and the displacement sensor is connected with an intelligent early warning device outside the anchor hole through a communication line passing through the hollow grouting rod body. Wherein the displacement sensor can be a mechanical wheel, an ultrasonic range finder or an infrared range finder.

By adopting the above design scheme, it effectively provides continuous and reliable support, safety monitoring, and early warning monitoring, which is suitable for market promotion and use.

Description of drawings

Fig. 1 is a schematic diagram of a dynamic and static combination intelligent early warning bolt according to Embodiment 1 of the present invention.

illustration

1-hollow grouting rod 2-sleeve

3-solid rod body 4-tray

5-Nut 6-External grout stopper

7-Inner pulp stopper 8-Baffle

9-Shear core 10-Displacement sensor

11-Communication line 12-Single-chip intelligent system

13-Cement mortar 14-Resin anchoring agent

15-Roadway wall 16-Cracked and softened area of surrounding rock

17-Elastic zone of surrounding rock 18-Crack softening zone and boundary of elastic zone

Detailed ways

The present invention will be described in further detail below in conjunction with the accompanying drawings and specific embodiments.

The dynamic and static combination intelligent early warning bolt provided in this embodiment is made of a hollow grouted rod body and a solid rod body with a shear core on the surface connected by a casing, which can adapt to the failure characteristics of hard and brittle surrounding rock under high ground stress conditions. It can resist the static and dynamic loads of hard and brittle surrounding caverns, and has the function of yielding support combined with dynamic and static; according to the yielding deformation characteristics of the rod body in the casing, a displacement sensor is installed in the casing to monitor the movement of the rod body Monitoring, the displacement sensor is connected with the single-chip intelligent system outside the anchor hole, and the single-chip intelligent system automatically analyzes the displacement of the rod body and sends out an audible and visual alarm.

Embodiment 1: Referring to shown in Fig. 1, the hard and brittle surrounding rock cavern will form a fracture softening zone 16 and an elastic zone 17 under the action of high ground stress, and the boundary 18 of the crack softening zone can be measured by acoustic wave testing equipment; According to the anchorage design specification, high-strength rebar is selected to process the hollow grouting rod body 1 and the solid rod body 3 respectively. The hollow grouting rod body 1 is provided with a grout hole, and its surface thread should facilitate the installation of the casing 2, the nut 5, the inner grout stopper 6 and the outer grout stopper 7, and the tray 4 and the outer grout stopper 6 are provided with exhaust holes. aisle. One end of the solid rod body 3 is a stirring wing, and the other end is socketed with a sleeve. The rod body at the sleeve end is provided with a cylindrical blocking block with a slightly larger diameter and a certain number of three sets of shear cores 9 on the surface. A circular sleeve 2 with two inner diameters, one small and one large, is processed. The small inner diameter of the sleeve 2 matches the outer diameter of the solid rod body 3, and the large inner diameter of the sleeve pipe 2 matches the outer diameter of the cylindrical blocking block of the solid rod body. Matching, the axial length of the casing 2 is determined according to the suitable deformation of the surrounding rock, the thread length of the hollow grouting rod body 1 and the size of the displacement sensor 10 . The displacement sensor 10 is fixed in the casing between the hollow grouting rod body 1 and the solid rod body 3, and the communication line 11 passes through the hollow tube of the hollow grouting rod body 1 and is connected with the single-chip intelligent system 12 outside the anchor hole.

The installation steps are as follows: First, according to the diameter of the anchor hole and the outer diameter of the solid rod body 3, a resin anchoring agent with a suitable diameter and length is selected for the anchoring of the solid rod body 3 rod head, and the solid rod body 3 rod head is provided with a stirring wing for drilling. Stir the resin anchoring agent, in order to prevent the casing 2 from being anchored and bonded, the solid rod 3 is provided with a baffle 8, which can also be used to control the anchoring length of the solid rod 3. After the solid rod body 3 is firmly anchored to the hole wall, start to tighten the tray 4 and the nut 5 to pre-tighten the anchor rod. When grouting the hollow grouting rod body 1, the cement mortar is injected through the grout hole, and the inner grout stopper 7 can prevent the casing 2 from being bonded. As the grout fills the rod tail, the air in the hole can be discharged through the exhaust channel until Fill to the outer grout stopper 6, so that the rod tail will be anchored and bonded by cement mortar; the communication line 11 is pulled, and the single-chip intelligent system 12 is fixed on the wall of the cavern. So far, the overall installation of the anchor rod is completed.

The working principle is as follows: under the action of the ground stress, the surrounding rock of the cavern deforms inwardly so that the anchor rod is in a pulled state, the solid rod body 3 tends to be pulled out of the casing 2, and the first group of shear cores 9 is in a compressive shear state. When the shear resistance formed by the small-diameter section of the casing 2 is greater than the shear strength of the first group of shear cores 9, the first group of shear cores 9 is sheared, and the solid rod body 3 is pulled out to be connected with the first group of shear cores 9 and the first group of shear cores 9. The two sets of shear cores 9 are spaced at corresponding lengths, and slide toward the outside of the casing, exhibiting pressure-yielding capability, and at this time, the second set of shear cores 9 is in a state of compression shear. At this time, the displacement sensor 10 can monitor the first moving length of the solid rod body 3. After receiving the signal from the displacement sensor 10, the single-chip intelligent system 12 will send a first-level early warning in the form of alarm sound and light. Similarly, after the second group of shearing cores 9 are cut off, the displacement sensor 10 can monitor the second moving length of the solid rod body 3, and the single-chip intelligent system 12 issues a secondary warning; until the third group of shearing cores 9 are cut off , the single-chip microcomputer intelligent system 12 sends a three-level early warning, prompting that the surrounding rock dynamic disaster is coming, and personnel can be required to temporarily evacuate to avoid danger. At this time, the cylindrical blocking block will prevent the solid rod body 3 from sliding out of the casing 2, and the bolt will no longer give way, showing a high bearing capacity corresponding to that of ordinary threaded steel bolts, effectively resisting the damage of surrounding rock dynamic disasters, Gain time for the safe evacuation of personnel.

The invention is a dynamic and static combination intelligent early warning bolt, which can adapt to the static and dynamic failure characteristics of hard and brittle surrounding rock under relatively high ground stress conditions, and not only has the ability to resist the static and dynamic loads of hard and brittle surrounding caverns. It also has the function of monitoring and early warning, which can realize the effective prevention and control of dynamic disasters in hard and brittle surrounding rocks.

The above embodiment is only a preferred embodiment of the present invention, but not all of the content of the present invention. All equivalent transformations and changes made within the scope of the spirit of the present invention will fall within the protection scope of the present invention.

Claims (4)

1. A dynamic and static combination intelligent early warning bolt, which is formed by connecting a hollow grouting rod body (1) and a solid rod body (3) through a sleeve (2), and the hollow grouting rod body (1) is equipped with a tray (4 ) and nuts (5), wherein: the hollow grouting rod body (1) and the solid rod body (3) are bonded and anchored with the surrounding rock of the hole wall; the casing (2) includes a large inner diameter section and a small inner diameter section , not bonded with the surrounding rock of the hole wall; the solid rod section (3) can pass through the large inner diameter section of the casing (2), but part of the shaft cannot pass through the small inner diameter of the casing (2) section; the casing (2) is arranged near the boundary of the fracture softening zone (16) and the elastic zone (17) inside the surrounding rock, and it is characterized in that: the hollow grouting rod body (1) and the solid rod body (3 ) is fixed with a displacement sensor (10) in the sleeve pipe, and the displacement sensor (10) passes through the communication line (11) passing through the hollow grouting rod body (1) and the intelligent early warning device ( 12) Connected. 2. The dynamic and static combination intelligent early warning bolt according to claim 1, characterized in that: the displacement sensor (10) is a mechanical wheel. 3. The dynamic and static combination intelligent early warning bolt according to claim 1, characterized in that: the displacement sensor (10) is an ultrasonic rangefinder. 4. The dynamic and static combination intelligent early warning bolt according to claim 1, characterized in that: the displacement sensor (10) is an infrared rangefinder.

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