A method for judging the anchoring depth of a cable bolt

Abstract

The present invention discloses a method for determining the anchorage depth of a cable bolt, which comprises the following steps: S1, developing a monitoring device for the drilling depth of a cable bolt; S2, installing the monitoring device for the drilling depth of a cable bolt on a drilling rig according to the characteristics of the drilling rig; S3, collecting drilling data and calculating the drilling depth; S4, judging the anchorage depth of the cable bolt according to the relationship curve between the drilling depth and the net drilling time. The present invention has the characteristics of simple operation, wireless data transmission, strong applicability, etc., and provides a decision for the determination of the anchorage depth of the cable bolt in slope protection.

Description

Technical Field

[0001] The present invention relates to the technical field of slope protection. More specifically, the present invention relates to a method for determining the anchoring depth of anchor cables. Background Art

[0002] Highway and railway projects involve mountain excavation, forming a large number of high and steep slopes. Protecting the slopes and maintaining the long-term stability of high and steep slopes are one of the key points and difficulties of the projects. For high and steep slopes with poor rock mass strength and structure, anchor cables are usually used for anchoring. This process has the advantages of high utilization rate of mechanical equipment, fast construction speed and good protection effect. The anchoring effect of the anchor cable depends on the anchoring length, that is, the buried depth of the anchor cable in the relatively intact rock mass. This requires that during the drilling process of the anchor cable, the depth of penetration into the relatively intact rock mass should be judged in time to ensure that it is greater than the anchoring length to meet the designed anchoring force.

[0003] In design, the method of core drilling is usually used to judge the buried depth of the intact rock mass, and there are strict requirements for the number of core drillings. This technology has the disadvantages of high drilling cost and rough formation judgment. Summary of the Invention

[0004] An object of the present invention is to provide a method for determining the anchoring depth of anchor cables, which has the characteristics of simple operation, wireless data transmission, strong applicability, etc., and provides a decision for the determination of the anchoring depth of anchor cables in slope protection.

[0005] In order to achieve these objects and other advantages according to the present invention, a method for determining the anchoring depth of anchor cables is provided. During the drilling process of the anchor cable, the drilling depth of the drill rig into the soil is obtained, a curve of the drilling depth and the net drilling time is drawn, and according to the slope of the curve, the curve segment corresponding to the complete formation is judged, and the drilling depth corresponding to the complete formation curve segment is the anchoring depth of the anchor cable.

[0006] Preferably, it specifically includes the following steps:

[0007] Step S1, develop an anchor cable drilling depth monitoring device, which is used to obtain the drilling depth of the drill rig into the soil;

[0008] Step S2, install the anchor cable drilling depth monitoring device at a set position of the drill rig;

[0009] Step S3, obtain and calculate the drilling depth of the drill rig into the soil in real time through the anchor cable drilling depth monitoring device until the anchor cable drilling is completed;

[0010] Step S4, draw a curve of the drilling depth and the net drilling time, and according to the slope of the curve, the curve segment with the largest slope is the curve segment corresponding to the complete formation, and the drilling depth corresponding to it is the anchoring depth of the anchor cable.

[0011] Preferably, before plotting the curve of the drilling depth versus the net drilling time, a curve of the drilling depth versus the drilling time is also plotted, and the data of the displacement change caused by non-drilling during the drilling process, which is generated when cutting debris is discharged, is also included in the figure. The curve of the drilling depth versus the net drilling time formed after removing this data is the final judgment curve.

[0012] Preferably, the method for removing the displacement change data caused by non-drilling is as follows: during the non-drilling process, the stage where the displacement decreases sharply and then increases is defined as the V-shaped section. Taking the displacement parameter before the V-shaped section as the starting point, draw a horizontal line along the time axis. The horizontal line intersects the V-shaped section, and the first point after the intersection point is taken and connected to the starting point, that is, a displacement change data during the non-drilling process is deleted; and so on, all the displacement change data during the non-drilling process is deleted to obtain the curve of the drilling depth versus the net drilling time for final judgment.

[0013] Preferably, the anchor cable drilling depth monitoring device includes a pull rope displacement sensor, a power supply, a data transmission unit and a terminal. The power supply is used to supply power to the data transmission unit. The pull rope displacement sensor is used to collect the displacement data of the power head. The data transmission unit is used to transmit the data collected by the pull rope displacement sensor to the terminal. The terminal is used to wirelessly receive the data and can view, download and calculate and process the data. The pull rope displacement sensor is connected to the power head of the drill rig, and the pull rope of the pull rope displacement sensor is parallel to the movement direction of the power head.

[0014] Preferably, the anchor cable drilling depth monitoring device is installed in a fixed box. One side of the fixed box has a through hole, which is used to accommodate the pull rope of the pull rope displacement sensor to extend out and connect to the power head.

[0015] Preferably, one side surface of the fixed box is set as a movable door, and the power supply is installed inside the movable door.

[0016] Preferably, the bottom of the fixed box facing the power head is provided with a through hole. The fixed box is fixed on the chute of the drill rig through a fixing frame. The fixing frame includes a fixing plate and four angle steels. The fixing plate is fixed at a set position on the chute. The four angle steels are respectively fixed at the four corners of the fixing frame. The fixed box is located in the rectangular space formed by the four angle steels, and the length, width and height dimensions of the fixed box are all smaller than the rectangular space formed by the four angle steels. The gap between the fixed box and the angle steel is filled with at least one base plate to adjust the pull rope of the pull rope displacement sensor to be parallel to the movement direction of the power head. The fixed box is tied to the chute through a binding band.

[0017] Preferably, the movable door is arranged on the top surface of the fixed box directly above the chute.

[0018] The present invention has at least the following beneficial effects:

[0019] The method for determining the anchoring depth of the anchor cable of the present invention is easy to implement and has a high accuracy rate. Compared with the conventional core drilling discrimination technology, it saves a large amount of costs and achieves a refined discrimination of the anchoring depth. The anchor cable drilling depth monitoring device involved in the method for determining the anchoring depth of the anchor cable of the present invention has the characteristics of cheap components, simple assembly, and convenient installation on the drilling rig, and realizes the functions of real-time data acquisition and remote transmission of the monitoring data.

[0020] Other advantages, objectives, and features of the present invention will be partially reflected by the following description and partially understood by those skilled in the art through the research and practice of the present invention. Description of the Drawings

[0021] Figure 1 It is a schematic assembly diagram of the anchor cable drilling depth monitoring device of the present invention;

[0022] Figure 2 It is a schematic installation diagram of the anchor cable drilling depth monitoring device of the present invention on the drilling rig;

[0023] Figure 3 It is a curve of the measured data and the displacement change caused by non-drilling of the present invention;

[0024] Figure 4 It is a schematic diagram for determining the anchoring depth according to the drilling depth - net drilling time curve of the present invention;

[0025] Figure 5 It is a top view of the fixed box of the present invention.

[0026] Description of the Reference Numerals:

[0027] 1. Anchor cable drilling depth monitoring device; 2. Drilling rig; 3. Power head; 4. Drill pipe; 5. Drill bit; 6. Slide groove; 7. Fixed box; 8. Activity door; 9. Angle steel; 10. Fixed plate. Detailed Embodiment

[0028] The following further describes the present invention in detail with reference to the drawings, so that those skilled in the art can implement it according to the description in the specification.

[0029] It should be noted that, unless otherwise specified, the experimental methods described in the following implementation schemes are all conventional methods, and the reagents and materials, unless otherwise specified, can all be obtained from commercial channels; in the description of the present invention, the terms "lateral", "longitudinal", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation to the present invention.

[0030] As Figures 1 to 4 shown, the present invention provides a method for discriminating the anchoring depth of a cable bolt. During the process of drilling the cable bolt hole, the drilling depth of the drill rig 2 drilling into the soil body is obtained, a curve of the drilling depth and the net drilling time is plotted, and according to the slope of the curve, the curve segment corresponding to the complete formation is judged, and the drilling depth corresponding to the complete formation curve segment is the anchoring depth of the cable bolt.

[0031] In the above technical solution, existing research shows that rock characteristics have an important impact on the drilling response. The measurement-while-drilling technology that records drilling parameters to monitor the performance of the drill rig can evaluate the characteristics of rock mass changes with high resolution. Especially for fractured rock mass and intact rock mass, there are obvious differences in their drilling rates. The integrity of the rock mass is judged by using the relationship between the drilling depth and the net drilling time, so as to obtain different geological layers corresponding to different drill rig depths, and thus obtain the drilling depth corresponding to the complete formation, which is the anchoring depth of the cable bolt.

[0032] In another technical solution, it specifically includes the following steps:

[0033] Step S1: Develop a cable bolt hole depth monitoring device 1, which is used to obtain the drilling depth of the drill rig 2 drilling into the soil body;

[0034] Step S2: According to the characteristics of the drill rig 2, install the cable bolt hole depth monitoring device 1 at the set position of the drill rig 2. An embodiment of the present application is to install it on the chute 6 of the drill rig 2 and directly above the power head 3 also located on the chute 6 in the direction of the chute 6. As Figure 2 shown, the cable bolt hole depth monitoring device 1 is fixed to the tail of the power head 3 of the drill rig 2 and fixed by welding or tying to ensure firm fixation and prevent shaking;

[0035] Step S3: Real-time obtain and calculate the drilling depth of the drill rig 2 drilling into the soil body through the cable bolt hole depth monitoring device 1, that is, collect drilling data until the cable bolt hole drilling is completed;

[0036] Step S4, drawing a curve of drilling depth and net drilling time. According to the slope of the curve, the curve segment with the largest slope is the curve segment corresponding to the complete formation, and the corresponding drilling depth is the anchoring depth of the anchor cable.

[0037] In the above technical scheme, the slope drilling rig 2 currently used for anchor cable drilling is almost not equipped with a measurement while drilling system. The anchor cable drilling depth monitoring device 1 of the present application can be quickly and conveniently installed on the slope drilling rig 2 to realize data collection and wireless transmission, and quickly determine the depth of the drill bit 5 drilling into the intact rock mass, providing a decision for the determination of the anchor cable anchoring depth in slope protection. Step S4 determines the anchor cable anchoring depth based on the relationship curve between the drilling depth and the net drilling time, which refers to drawing a curve of the drilling depth and the net drilling time, and determining the broken strata and the intact strata based on the slope of the curve. The drilling depth of the intact stratum is the anchor cable anchoring depth. The slope of the curve corresponding to the broken stratum is smaller, and the drilling speed is slow; the slope of the curve corresponding to the intact stratum is larger, and the drilling speed is fast. See attached. Figure 4 shown.

[0038] In another technical solution, Figure 3 and Figure 4 As shown, before the curve of drilling depth and net drilling time is drawn, a curve of drilling depth and drilling time is also drawn, which also includes the displacement change data caused by non-drilling when the cuttings are discharged during the drilling process. The curve of drilling depth and net drilling time formed after eliminating this data is the final judgment curve.

[0039] In the above technical solution, the collection of drilling data in step S3 refers to the process of anchor cable drilling, in which the power head 3 will push the drill bit 5 at the front end of the drill rod 4 to impact the rock in the hole, and the high-pressure gas will blow the rock debris and dust out of the hole, and the drill bit 5, the drill rod 4 and the power head 3 will continue to advance into the hole. The pull rope displacement sensor in the anchor cable drilling depth monitoring device 1 fixed on the power head 3 records the drilling depth information. The calculation of the drilling depth in step S3 refers to the process in which when the drill rig 2 encounters broken rock, the captain of the drill rig 2 will pump the drill rod 4 and the drill bit 5 back and forth to remove the broken rock debris out of the hole. This process will produce displacement changes not caused by drilling (see attached Figure 3 Therefore, the data generated by this process needs to be eliminated, and the remaining data can represent the drilling depth.

[0040] In another technical solution, a method for eliminating displacement change data caused by non-drilling is as follows: during the non-drilling process, the stage in which the displacement decreases sharply and then increases is defined as a V-shaped segment. The displacement parameter before the V-shaped segment is taken as the starting point, and a horizontal line is drawn along the time axis. The horizontal line intersects with the V-shaped segment, and the first point after the intersection is taken and connected to the starting point, thereby deleting the displacement change data of a non-drilling process; and by analogy, all the displacement change data of the non-drilling process are deleted to obtain the final judgment of the drilling depth and net drilling time curve.

[0041] In the above technical solution, data generated without drilling, such as Figure 3 shown by the oval wireframe in, it can be seen that during normal drilling, the displacement increases with time. During the non-drilling process, the displacement shows a phenomenon of sharp decrease and then increase, which is defined as the V-shaped section. According to the drilling process, the increase in displacement must be caused by the impact of the drill bit 5 on the rock mass, resulting in rock fragmentation and increased footage. Therefore, only by taking the displacement parameter before the V-shaped section as the starting point, drawing a horizontal line along the time axis, the horizontal line intersects with the V-shaped section, taking the first point after the intersection point and connecting it with the starting point, one non-drilling process is deleted. By analogy, all non-drilling processes are deleted to obtain the drilling depth and net drilling time curve.

[0042] In another technical solution, as Figure 1 shown, the anchor cable drilling depth monitoring device 1 includes a pull rope displacement sensor, a power supply, a data transmission unit and a terminal. The power supply is used to supply power to the data transmission unit. The pull rope displacement sensor is used to collect the displacement data of the power head 3. The data transmission unit is used to transmit the data collected by the pull rope displacement sensor to the terminal. The terminal is used to wirelessly receive data and can view, download and calculate and process the data. The pull rope displacement sensor is connected to the power head 3 of the drilling rig 2, and the pull rope of the pull rope displacement sensor is parallel to the movement direction of the power head 3.

[0043] In the above technical solution, in one implementation, the power supply can be a rechargeable lithium battery, the data transmission unit is a DTU, which is built-in with a flow card, and the terminal is a mobile phone or a computer terminal. The lithium battery supplies power to the DTU; the DTU is connected to the pull rope displacement sensor to collect displacement data; the flow card built in the DTU transmits the data to the mobile phone or computer terminal; view or download data or calculate and process data on the DTU cloud service platform.

[0044] In another technical solution, the anchor cable drilling depth monitoring device 1 is installed in a fixed box 7. One side of the fixed box 7 has a through hole, which is used to accommodate the pull rope of the pull rope displacement sensor to extend out and connect to the power head 3.

[0045] In the above technical solution, other modules related to the anchor cable drilling depth monitoring device 1 except the terminal are fixed in a sealed metal or hard plastic fixed box 7. A through hole is opened on one side of the box to leave space for the pull rope in the pull rope displacement sensor. The pull rope of the pull rope displacement sensor is pulled out from the through hole and vertically fixed on the power head 3. The pull rope is parallel to the movement direction of the power head 3. It is strictly prohibited to pull out the pull rope obliquely.

[0046] In another technical solution, one side surface of the fixed box 7 is set as a movable door 8, and the power supply is installed inside the movable door 8. The fixed box 7 is provided with a movable door 8 that is convenient to open, which is convenient for replacing the lithium battery or maintenance.

[0047] In another technical solution, as Figure 5 shown, the fixed box 7 is provided with a through hole at the bottom facing the power head 3. The fixed box 7 is fixed on the chute 6 of the drilling rig 2 through a fixing frame. The fixing frame includes a fixing plate 10 and four angle steels 9. The fixing plate 10 is fixed at a set position of the chute 6. The four angle steels 9 are respectively fixed at the four corners of the fixing frame. The fixed box 7 is located in the rectangular space formed by the four angle steels 9. And the length, width and height dimensions of the fixed box 7 are all smaller than the rectangular space formed by the four angle steels 9. The gap between the fixed box 7 and the angle steel 9 is filled with at least one foundation cushion block to adjust the pull rope of the pull rope displacement sensor to be parallel to the movement direction of the power head 3. The fixed box 7 is tied to the chute 6 through a binding band.

[0048] In the above technical solution, the position of the fixed box 7 is initially positioned through the fixing frame, and then the inclination of the fixed box 7 is adjusted by filling foundation cushion blocks at the bottom of the fixed box 7 and the fixing frame. The horizontal position of the fixed box 7 is adjusted by filling different numbers of foundation cushion blocks in the gaps between the fixed box 7 and the angle steels 9 at different positions on the fixing frame, so as to accurately adjust the pull rope of the pull rope displacement sensor to be parallel to the movement direction of the power head 3. After the adjustment is completed, the position of the fixed box 7 is fixed by binding. Through the double settings of the binding band and the foundation cushion block, the fixed box 7 can be firmly fixed. The foundation cushion block is a relatively thin steel structure cushion block.

[0049] In another technical solution, the movable door 8 is arranged on the top surface of the fixed box 7 directly above the chute 6. On the one hand, arranging the movable door 8 on the top surface can make the connection with the fixed box 7 more stable under the action of gravity. On the other hand, after the fixed box 7 is tied with a binding band, the movable door 8 can also be tied tighter.

[0050] Although the embodiments of the present invention have been disclosed as above, it is not limited to the applications listed in the specification and embodiments. It can be fully applied to various fields suitable for the present invention. For those familiar with the field, other modifications can be easily realized. Therefore, without departing from the general concept defined by the claims and the equivalent scope, the present invention is not limited to the specific details and the illustrated examples here.

Claims

1. A method for determining the anchoring depth of a cable anchor, characterized in that, during the drilling process of the cable anchor, the drilling depth of the drill rig into the soil is obtained, a curve of the drilling depth versus the net drilling time is plotted, and according to the slope of the curve, the curve segment corresponding to the complete formation is judged, and the drilling depth corresponding to the complete formation curve segment is the anchoring depth of the cable anchor; specifically includes the following steps: Step S1, develop a cable anchor drilling depth monitoring device for obtaining the drilling depth of the drill rig into the soil; Step S2, install the cable anchor drilling depth monitoring device at a set position on the drill rig; Step S3, obtain and calculate in real time the drilling depth of the drill rig into the soil through the cable anchor drilling depth monitoring device until the cable anchor drilling is completed; Step S4, plot a curve of the drilling depth versus the net drilling time, and judge the anchoring depth of the cable anchor according to the relationship curve of the drilling depth versus the net drilling time, that is, plot a curve of the drilling depth versus the net drilling time, and according to the slope of the curve, judge the fractured formation and the complete formation. The drilling depth of the complete formation is the anchoring depth of the cable anchor. The slope of the curve corresponding to the fractured formation is smaller and the drilling speed is slower; the slope of the curve corresponding to the complete formation is larger and the drilling speed is faster; Before plotting the curve of the drilling depth versus the net drilling time, a curve of the drilling depth versus the drilling time is also plotted, and the figure also includes the displacement change data caused by non-drilling during the drilling process when discharging cuttings. The curve of the drilling depth versus the net drilling time formed after removing this data is the final judgment curve; The method for removing the displacement change data caused by non-drilling is as follows: during non-drilling, the stage where the displacement suddenly decreases and then increases is defined as the V-shaped section. Take the displacement parameter before the V-shaped section as the starting point, draw a horizontal line along the time axis, the horizontal line intersects with the V-shaped section, take the first point after the intersection point, and connect it with the starting point, that is, a displacement change data during non-drilling is deleted; and so on, delete all the displacement change data during non-drilling to obtain the final judged curve of the drilling depth versus the net drilling time.

2. The method for determining the anchoring depth of a cable anchor according to claim 1, characterized in that, the cable anchor drilling depth monitoring device includes a pull rope displacement sensor, a power supply, a data transmission unit and a terminal. The power supply is used to supply power to the data transmission unit. The pull rope displacement sensor is used to collect the displacement data of the power head. The data transmission unit is used to transmit the data collected by the pull rope displacement sensor to the terminal. The terminal is used to wirelessly receive data and can view, download and calculate and process the data. The pull rope displacement sensor is connected to the power head of the drill rig, and the pull rope of the pull rope displacement sensor is parallel to the movement direction of the power head.

3. The method for determining the anchoring depth of a cable anchor according to claim 2, characterized in that, the cable anchor drilling depth monitoring device is installed in a fixed box, and one side of the fixed box has a through hole for accommodating the pull rope of the pull rope displacement sensor to extend out and connect to the power head.

4. The method for determining the anchoring depth of a cable anchor according to claim 3, characterized in that, one side surface of the fixed box is set as a movable door, and the power supply is installed inside the movable door.

5. The method for determining the anchoring depth of a cable anchor according to claim 4, characterized in that, The fixing box is provided with a through hole at the bottom facing the power head. The fixing box is fixed on the chute of the drill rig through a fixing frame. The fixing frame includes a fixing plate and four angle steels. The fixing plate is fixed at a set position on the chute, and the four angle steels are respectively fixed at the four corners of the fixing frame. The fixing box is located within the rectangular space formed by the four angle steels, and the length, width, and height dimensions of the fixing box are all smaller than the rectangular space formed by the four angle steels. The gap between the fixing box and the angle steels is filled with at least one foundation backing plate to adjust the pull rope of the pull rope displacement sensor to be parallel to the moving direction of the power head. The fixing box is tied to the chute through a binding strap.

6. The method for discriminating the anchoring depth of the anchor cable according to claim 5, characterized in that, the movable door is arranged on the top surface of the fixing box directly above the chute.

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