Anchor rod with memory function

Abstract

The anchor rod with the memory function comprises a rod body, a temperature control device and a plurality of deformable shape memory alloy pieces, the temperature control device is connected with the shape memory alloy pieces through temperature control wires and controls the temperature of the shape memory alloy pieces, and the temperature control device controls the shape memory alloy pieces to change between two forms. The system further comprises a monitoring device used for receiving signals of the strain sensors, and the monitoring device and the strain sensors are connected through monitoring wires. The anchor rod is simple in expansion mode, small in influence on pore water pressure of a soil body and small in disturbance to a soil layer; friction force can be adjusted and increased in time, short-time rapid supporting is achieved, slope stability is maintained, and time is won for rescue and relief work; the device is high in assembly degree, simple, practical, light, high in strength, economical and environment-friendly; and the recycling function can be achieved, the rescue and disaster relief cost is greatly reduced, geological parameters can be monitored, and the use convenience degree and the working efficiency are high.

Description

Technical Field

[0001] The utility model relates to the technical field of geotechnical engineering devices, in particular to an anchor rod with a memory function, which is easy to recycle and can monitor geological conditions and guide the use of the anchor rod. Background Art

[0002] Anchor rods are widely used as an economical support tool. However, the traditional anchor rod support method requires a large amount of work, a long installation time, and a long grouting solidification time, which does not meet the needs of rapid rescue and disaster relief, such as major sudden landslide disasters such as slope instability caused by earthquakes and slope instability caused by rainfall.

[0003] The support principle of friction anchors is advanced, the structure is simple, the installation is convenient, the anchoring force is large, the load is timely, the support strain capacity is strong, and grouting is not required. It is suitable for supporting various types of slopes. However, the existing friction anchors have the following disadvantages: the friction of the anchor in the borehole is difficult to control, which can easily cause the friction to be too small and the load-bearing capacity to be insufficient, or the friction to be too large and the support cost to increase; while the anchor is supporting, it is impossible to monitor the stress and displacement of the anchor and the soil inside the slope, and it is impossible to timely feedback the monitoring data to analyze and evaluate the stress state of the anchor and the stability of the slope to prevent the slope from becoming unstable and sliding again; after rapid rescue and disaster relief, the anchor cannot be recovered quickly or even cannot be recovered, resulting in increased rescue and disaster relief costs. At the same time, how to accurately judge the geological conditions to adjust the use of the anchor is also lacking in the existing anchor design. Utility Model Content

[0004] The utility model provides an anchor rod with a memory function, which is used to solve the technical problems mentioned in the background technology.

[0005] In order to solve the above technical problems, the technical solution proposed by the utility model is:

[0006] An anchor rod with a memory function comprises a rod body, a temperature control device and a plurality of deformable shape memory alloy sheets, wherein the temperature control device is connected to the shape memory alloy sheets via a temperature control wire and controls the temperature of the shape memory alloy sheets, the head end of the shape memory alloy sheets is fixed on the rod body, and the shape memory alloy sheets have two forms, an expanded state and a contracted state, and the temperature control device controls the shape memory alloy sheets to change between the two forms: when the temperature control device heats up the shape memory alloy sheets, the tail end of the shape memory alloy sheets rises and forms a certain angle with the rod body, and when the temperature control device cools down the shape memory alloy sheets, the shape memory alloy sheets fit with the rod body; a strain sensor is arranged at the tail end of the shape memory alloy sheets, and the anchor rod with a memory function also comprises a monitoring device for receiving signals from the strain sensor, and the monitoring device and the strain sensor are connected via a monitoring wire.

[0007] The above-mentioned anchor rod with memory function has a shape memory alloy sheet in martensite phase. When the temperature reaches the starting point of austenite phase transformation by heating it through a temperature control device, the shape memory alloy sheet begins to transform; when the temperature reaches the end temperature of austenite phase transformation, the alloy sheet is in austenite phase, the alloy becomes straight, and fits with the rod body; after the anchor rod is installed in the borehole, the power is cut off through the temperature control device, and the alloy sheet begins to reduce the temperature. When the temperature drops to the starting point of the reverse martensite phase transformation, the internal crystal phase of the alloy changes, and recovery stress is generated, and the alloy begins to recover in shape and squeeze the soil; when the temperature drops to the end point of the reverse martensite phase transformation, the shape memory alloy sheet is completely restored to martensite, that is, the shape memory alloy sheet is in an expanded state, and the interaction with the soil reaches a static equilibrium state, and the expansion force of the shape memory alloy sheet no longer changes; because the alloy sheet is hindered by the soil around the borehole, the alloy sheet cannot return to the preset bending shape, but will generate considerable expansion force to squeeze the surrounding soil, and when the anchor rod is pulled, the rock or soil and the anchor rod generate friction between each other, thereby providing anchoring bearing capacity.

[0008] As a further preferred embodiment of the above technical solution, the outer sleeve of the shape memory alloy sheet is provided with a friction material sleeve; the strain sensor and part of the monitoring wires and the temperature control wires are also wrapped by the friction material sleeve; the friction material sleeve is a synthetic resin sleeve.

[0009] As a further preferred embodiment of the above technical solution, the surface of the rod body is provided with threads, the head end of the shape memory alloy sheet is fixed on the surface of a sleeve, and the sleeve is fixed on the rod body by threaded engagement.

[0010] As a further preferred embodiment of the above technical solution, the rod body is a hollow structure, and wire holes are provided on the tail ends of the rod body, the sleeve and the shape memory alloy sheet. A wire groove is also provided on the side of the shape memory alloy sheet facing the rod body, and the wire groove is connected with the wire hole; the temperature control wire is connected to the shape memory alloy sheet via the wire holes inside the rod body and the sleeve; the monitoring wire is connected to the strain sensor via the wire holes inside the rod body, the sleeve, the wire groove and the shape memory alloy sheet.

[0011] As a further preferred embodiment of the above technical solution, the rod body is a glass fiber reinforced plastic tube, including a free section rod body and an anchoring section rod body, the free section rod body and the anchoring section rod body are connected by threads, and the shape memory alloy sheet is fixed on the anchoring section rod body.

[0012] Compared with the prior art, the utility model has the following beneficial effects:

[0013] (1) The anchor rod with memory function of the utility model is simple to expand. During the expansion process, the pore water pressure of the soil is slightly affected and the soil layer is slightly disturbed. The anchor force can be adjusted by adjusting the number of anchoring devices and the thickness and shape of the shape memory alloy sheet. The friction force can be adjusted in time to increase the friction force, quickly support in a short time, maintain the stability of the slope, and buy time for disaster relief. The utility model has a high degree of assembly, is simple and practical, light and high-strength, economical and environmentally friendly. The temperature control device is electrically heated. When the temperature reaches the starting point of the austenite phase transformation, the alloy sheet begins to change phase. When the temperature reaches the end temperature of the austenite phase transformation, the alloy sheet is in the austenite phase, the alloy becomes straight, and sticks to the rod body. No more pressure is generated on the soil, the frictional resistance disappears, the anchor rod loses its bearing capacity, and the anchor rod is pulled out of the borehole. The method is simple to operate and can quickly and conveniently recover the anchor rod, realizing the recycling function and greatly reducing the cost of disaster relief.

[0014] (2) After the anchor rod with memory function of the utility model is placed in the borehole and begins to expand with power off, it is found that the stress state of the anchor rod is normal and the slope is stable through observation of the monitoring device and analysis of the monitoring data. The slope that needs rapid rescue and disaster relief can be supported by reducing the number of anchor rods. In this way, the support time can be reduced, and the time advantage can be gained for rapid rescue and disaster relief operations. The support can be completed and the injured or damaged facilities can be rescued in the shortest time, thereby reducing the support cost. At the same time, due to the presence of the monitoring device, during the rescue and disaster relief process, if the slope continues to be affected by aftershocks or rainfall, by monitoring the stress displacement in the anchor rod and the slope body, the abnormal stress state of the anchor rod can be discovered in time. If there is a sign of instability in the slope, the anchor rod support force and the number of anchor rod support can be increased in time, the anchor rod support strength can be increased in a short time, and an early warning can be issued in the first time to avoid the slope from becoming unstable again, causing greater casualties and property losses. When the soil undergoes unstable changes, the extrusion pressure generated by the shape memory alloy sheet and the borehole wall will change. The strain sensor installed on the alloy sheet receives the change data and transmits the change signal to the monitoring device through the monitoring wire. The monitoring device transmits a signal to the staff to monitor the stress and displacement of the anchor rod and the soil inside the slope, and timely feedback the monitoring data and the stress state of the anchor rod, as well as analyze and evaluate the stability of the slope to prevent the slope from becoming unstable and sliding again. This improves the reliability of the anchor rod of this scheme when in use, and further improves the convenience and work efficiency of anchor rod assembly.

[0015] (3) The anchor rod with memory function of the utility model is provided with a wire hole at the free end of the shape memory alloy sheet, and a wire groove is provided on the side of the shape memory alloy sheet that is in contact with the rod body. The wire of the ductility monitoring device is used. When the shape memory alloy sheet is in use and when the phase changes, the sensor wire can be protected to prevent it from being damaged, thereby reducing the maintenance cost of the wire, giving full play to the great advantages of the anchor rod and making the anchor rod structure more sophisticated.

[0016] (4) In the anchor rod with memory function of the utility model, the friction material sleeve surrounds the shape memory alloy sheet, the strain sensor and the wire in the wire groove. While protecting the wire and preventing the wire from falling out during deformation, the friction material sleeve itself has a high friction coefficient when in contact with the soil. Under the same pressure, the friction force generated by the shape memory alloy sheet equipped with the friction material sleeve is greater, which is more conducive to improving the anchoring bearing capacity of the anchor rod.

[0017] The present invention will be further described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention. In the drawings:

[0019] Figure 1 This is a schematic diagram of the three-dimensional structure of the tail end of the anchor rod with memory function according to Example 1 of the utility model (in the power-off cooling state);

[0020] Figure 2 This is a schematic diagram of the cross-sectional structure of the tail end of the anchor rod with memory function according to Example 1 of the utility model (in the power-off cooling state);

[0021] Figure 3 This is a schematic diagram of the connection between the shape memory alloy sheet and the sleeve of the anchor with memory function in Example 1 of the utility model (cross-sectional direction in the power-off cooling state);

[0022] Figure 4 This is a schematic diagram of the connection between the shape memory alloy sheet and the sleeve of the anchor rod with memory function in Example 1 of the utility model (side view in the state of power-on heating);

[0023] Figure 5 This is a schematic diagram of the application of an anchor rod with memory function according to Example 1 of the utility model.

[0024] Legend:

[0025] 1. Anchor; 2. Rod body; 21. Free section rod body; 22. Anchor section rod body; 3. Monitoring device; 31. Monitoring wire; 4. Temperature control device; 41. Temperature control wire; 5. Sleeve; 6. Shape memory alloy sheet; 61. Wire groove; 7. Strain sensor; 8. Friction material sleeve; 9. Screw; 11. Soil; 12. Drill hole; 13. Wire hole. DETAILED DESCRIPTION

[0026] The embodiments of the present invention are described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered by the claims.

[0027] Embodiment 1:

[0028] like Figure 1-4 As shown, the anchor rod with memory function of this embodiment includes a rod body 2 (divided into a free section rod body 21 located at the head and an anchor section rod body 22 located at the tail, and the two are connected), a temperature control device 4, a monitoring device 3, a sleeve 5, a plurality of shape memory alloy sheets 6, a temperature control wire 41, a monitoring wire 31, a plurality of strain sensors 7, and a friction material sleeve 8 (synthetic resin sleeve).

[0029] There are 6 shape memory alloy sheets 6 (the number is adjustable), which are evenly fixed on the outside of the sleeve 5 by screws 9. The inside of the sleeve 5 is provided with threads, and the outer surface of the anchoring section rod body 22 is provided with matching threads. The sleeve 5 is screwed into and fixed on the anchoring section rod body 22 by threaded matching. The number of strain sensors 7 corresponds to the number of shape memory alloy sheets 6, and is fixed on the outer surface of the tail end of the shape memory alloy sheet 6 by screws 9. The friction material sleeve 8 is sleeved outside the shape memory alloy sheet 6 and the strain sensor 7. The free section rod body 21 and the anchoring section rod body 22 are hollow glass fiber reinforced plastic pipes, and the two are connected by threaded matching. The anchoring section rod body 22 and the sleeve 5 are provided with wire holes 13, and the side of the shape memory alloy sheet 6 facing the rod body 2 is provided with a wire groove 61. The shape memory alloy sheet 6 is connected to the temperature control device 4 through the temperature control wire 41 and is electrically connected. One end of the temperature control wire 41 is connected to the temperature control device 4, and the other end is connected to the shape memory alloy sheet 6 via the head end of the free section rod body 21, the inside of the free section rod body 21, the inside of the anchor section rod body 22 and the wire hole 13. The temperature control device 4 controls the shape memory alloy sheet 6 to change between two forms: when the temperature control device 4 heats up the shape memory alloy sheet 6, the tail end of the shape memory alloy sheet 6 tilts up and makes the shape memory alloy sheet 6 form a certain angle with the rod body 2, and when the temperature control device 4 cools down the shape memory alloy sheet 6, the shape memory alloy sheet 6 fits with the rod body 2. The monitoring device 3 is connected to the strain sensor 7 through the monitoring wire 31 and receives the signal of the strain sensor 7. One end of the monitoring wire 31 is connected to the monitoring device 3, and the other end is connected to the strain sensor 7 via the head end of the free section rod body 21, the inside of the free section rod body 21, the inside of the anchor section rod body 22 and the wire hole 13, the wire groove 61, and the wire hole 13.

[0030] In this embodiment, the sleeve 5 is made of 45 steel, and the shape memory alloy sheet 6 is made through "training"; the "training" makes it have a fixed shape in the martensite phase and the austenite phase, and then the temperature is changed by the temperature control device 4 to induce phase change, thereby achieving the effect of shape recovery; different "trained" shape memory alloy sheets 6 can be selected according to different supporting soil bodies. In this embodiment, the thickness of the shape memory alloy sheet 6 is 7 mm, and the pull-out bearing capacity is 116.6 kN.

[0031] In this embodiment, the strain sensor 7 is a strain principle sensor, which detects the stress of an object by changing the resistance and capacitance of the material. When the anchor rod is subjected to external force, strain will be generated inside the sensor, and then an electrical signal will be generated. The signal processor converts the electrical signal into a numerical value, and the stress of the anchor rod can be obtained.

[0032] like Figure 5 As shown, the method for using the anchor rod with memory function in this embodiment is as follows: keep the temperature control device 4 powered on to heat up the shape memory alloy sheet 6 and shrink it to fit the rod body 2, then put the anchor rod into the drill hole 12 at the construction site, calculate the shear strength of the soil 11, control the temperature control device 4 to power off, so that the shape memory alloy sheet 6 cools down and restores its shape, and the shape memory alloy sheet 6 expands and squeezes the soil 11, and the strain sensor 7 on the tail end of the shape memory alloy sheet 6 monitors the data in real time. When the expansion stress of the shape memory alloy sheet 6 is about to exceed the allowable shear strength of the reinforced soil 11, immediately control the temperature control device 4 to power on to heat the shape memory alloy sheet 6 to fit the rod body, then take out the anchor rod, and replace it with a shape memory alloy sheet 6 with a small expansion stress. After that, the anchor rod is placed into the borehole 12 in the same way, and the temperature control device 4 is controlled to cut off the power and wait for the shape memory alloy sheet 6 to cool down and restore its shape to squeeze the soil 11, so that the strain sensor 7 can work normally and cooperate with the anchor 1 to achieve anchoring; after the strain sensor 7 works normally, it pays real-time attention to the information between the shape memory alloy sheet 6 and the soil 11. When the soil 11 changes due to external reasons, the strain sensor 7 can accurately sense the change of the force between the soil 11 and the shape memory alloy sheet 6, and transmit the data information to the monitoring device 3, and the monitoring device 3 sends an alarm message to the staff of the temporary support work; after the temporary support work is completed, the staff can recycle the anchor rod, so as to achieve the effect of easy recovery and rapid construction of temporary high-strength support.

[0033] The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. For those skilled in the art, improvements and changes obtained without departing from the technical concept of the present invention should also be regarded as the protection scope of the present invention.

[0034] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are illustrative and cannot be understood as limitations of the present invention. Ordinary technicians in the field can change, modify, replace and modify the above implementation methods within the scope of the present invention.

Claims

1. An anchor with memory function, characterized in that: The invention comprises a rod body (2), a temperature control device (4) and a plurality of deformable shape memory alloy sheets (6); the temperature control device (4) is connected to the shape memory alloy sheets (6) via a temperature control wire (41) and controls the temperature of the shape memory alloy sheets (6); the head end of the shape memory alloy sheets (6) is fixed to the rod body (2); the shape memory alloy sheets (6) have two states: an expanded state and a contracted state; the temperature control device (4) controls the shape memory alloy sheets (6) to change between the two states: when the temperature control device (4) causes the shape memory alloy sheets (6) to heat up, the temperature control device (4) controls the shape memory alloy sheets (6) to heat up, and the shape memory alloy sheets (6) to heat up. When the temperature control device (4) cools the shape memory alloy sheet (6), the tail end of the shape memory alloy sheet (6) is tilted and the shape memory alloy sheet (6) and the rod body (2) form a certain angle. When the temperature control device (4) cools the shape memory alloy sheet (6), the shape memory alloy sheet (6) and the rod body (2) are fitted together. A strain sensor (7) is provided at the tail end of the shape memory alloy sheet (6). The anchor rod with memory function further comprises a monitoring device (3) for receiving a signal from the strain sensor (7). The monitoring device (3) and the strain sensor (7) are connected via a monitoring wire (31).

2. The anchor rod with memory function according to claim 1, characterized in that: The outer cover of the shape memory alloy sheet (6) is provided with a friction material cover (8); the strain sensor (7) and part of the monitoring wire (31) and the temperature control wire (41) are also wrapped by the friction material cover (8); the friction material cover (8) is a synthetic resin cover.

3. The anchor rod with memory function according to claim 1, characterized in that: The surface of the rod body (2) is provided with threads, the head end of the shape memory alloy sheet (6) is fixed to the surface of a sleeve (5), and the sleeve (5) is fixed to the rod body (2) by means of threaded engagement.

4. The anchor rod with memory function according to claim 3, characterized in that: The rod body (2) is a hollow structure. The rod body (2), the sleeve (5) and the tail end of the shape memory alloy sheet (6) are provided with a wire hole (13). The side of the shape memory alloy sheet (6) facing the rod body (2) is also provided with a wire groove (61), and the wire groove (61) is connected to the wire hole (13). The temperature control wire (41) is connected to the shape memory alloy sheet (6) via the inside of the rod body (2) and the wire hole (13) of the sleeve (5). The monitoring wire (31) is connected to the strain sensor (7) via the inside of the rod body (2), the wire hole (13) of the sleeve (5), the wire groove (61) and the wire hole (13) of the shape memory alloy sheet (6).

5. The anchor rod with memory function according to any one of claims 1 to 4, characterized in that: The rod body (2) is a glass fiber reinforced plastic tube, comprising a free section rod body (21) and an anchor section rod body (22); the free section rod body (21) and the anchor section rod body (22) are connected via threads, and the shape memory alloy sheet (6) is fixed on the anchor section rod body (22).

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