A device and method for drilling in tunnel broken surrounding rock

Abstract

The present application relates to a kind of tunnel broken surrounding rock drilling device and method, drilling device includes outer protective cylinder, inner drilling cylinder, lengthening drill barrel and tail connecting piece, when drilling, first, inner drilling cylinder is installed in outer protective cylinder by thread with the same shaft, then whole drilling, cross broken surrounding rock, then inner drilling cylinder is connected to rotary power mechanism by lengthening drill barrel and tail connecting piece, continue drilling, outer protective cylinder is left in broken rock layer and play protective role, inner drilling cylinder continues drilling under the drive of lengthening drill barrel, form drilling hole;The present application is separated into two steps of protective cylinder burying and secondary drilling by setting inner and outer double-layer separable cylinder structure, the traditional drilling device and method are separated into two steps, pass through broken area surrounding rock using protective cylinder, and then guarantee the success rate of broken surrounding rock drilling.Therefore, the present application has the following advantages: simple structure, easy operation, strong practicality, wide application range.

Description

Technical Field

[0001] This invention belongs to the field of civil engineering and relates to a drilling technology for fractured surrounding rock in tunnels, specifically a drilling device and method for fractured surrounding rock in tunnels. Background Technology

[0002] Drilling of surrounding rock is one of the fundamental technologies in tunnel engineering, widely used in tunnel anchor installation, ground stress measurement, deep grouting of tunnel walls, and deep geological drilling of surrounding rock. It has a significant impact on obtaining information about deep surrounding rock, establishing deep surrounding rock support systems, improving the stress state of surrounding rock, and guiding scientific and efficient tunnel excavation. However, during the excavation of deep-buried high-stress tunnels, static brittle failure (splitting, buckling, and cracking) of shallow hard and brittle surrounding rock often occurs due to tunnel excavation disturbance, resulting in "onion-like layered fracturing" and the formation of shallow fracturing zones. Alternatively, tunnel excavation may cross fault fracture zones, leading to partial exposure of fracturing surrounding rock. Existing tunnel drilling equipment is mostly developed for drilling in surrounding rock. During drilling in fractured surrounding rock, accidents such as hole collapse, hole deviation, and drill jamming often occur due to the loose, porous structure of the fractured rock zone or uneven hardness of the surrounding rock, severely restricting the efficiency and success rate of drilling in surrounding rock.

[0003] Given the aforementioned defects in existing tunnel surrounding rock drilling methods and devices, which make it difficult to achieve safe and efficient drilling in fractured surrounding rock, a drilling device and method for tunnels in fractured surrounding rock is proposed. Summary of the Invention

[0004] This invention addresses the technical problems existing in the prior art, aiming to provide a simple, easy-to-operate, highly practical, and widely applicable drilling device and method for tunnel broken surrounding rock. This effectively avoids phenomena such as hole collapse, hole deviation, and drill jamming caused by surrounding rock fracturing that often occur during tunnel broken surrounding rock drilling, thereby improving the efficiency and success rate of tunnel broken surrounding rock drilling and ensuring the smooth progress of work such as anchor bolt installation, deep grouting of surrounding rock, and ground stress measurement.

[0005] The above-mentioned technical problems of the present invention are mainly solved by the following technical solutions:

[0006] On one hand, the present invention provides a drilling device for breaking surrounding rock in tunnels, comprising:

[0007] The outer protective cylinder can be detachably mounted on the rotary power mechanism via the first tail connector, and rotates under the drive of the rotary power mechanism to perform drilling.

[0008] The inner drilling tube is coaxially installed inside the outer protective tube via a threaded connection, and the front end of the inner drilling tube is equipped with a drill bit for drilling.

[0009] The extended drill barrel has its front end detachably connected to the end of the inner drilling barrel, and its tail end detachably mounted on the rotary power mechanism via a second tail connector. With the power provided by the rotary power mechanism, the inner drilling barrel is driven to drill.

[0010] When the outer protective casing is connected to the rotary power mechanism via the first tail connector, the inner drilling casing and the outer protective casing are drilled together as a whole. When the first tail connector is removed and the inner drilling casing is connected to the rotary power mechanism via the extended drill casing and the second tail connector, the rotary power mechanism can drive the inner drilling casing to rotate relative to the outer protective casing, thus achieving secondary drilling under the protection of the outer protective casing.

[0011] The outer protective cylinder has a full thread on its inner wall, and the inner drilling cylinder has a corresponding full thread on its outer side.

[0012] Preferably, by selecting the thread direction between the inner drilling cylinder and the outer protective cylinder, the rotation direction of the secondary drilling is the same as the rotation direction of the overall drilling.

[0013] Preferably, the first tail connector is a first end cap, which is connected to the tail of the outer protective cylinder by a threaded connection.

[0014] Preferably, the extended drill barrel is connected to the tail end of the inner drilling barrel via a threaded connection; the second tail end connector is a second end cap, which is connected to the tail end of the inner drilling barrel via a threaded connection.

[0015] Preferably, the first end cover and the second end cover are respectively provided with connecting parts that are connected to the rotary power mechanism.

[0016] Preferably, the connector includes a connecting hole disposed on the first end cap and the second end cap, and an extension rod connected to the connecting hole.

[0017] Preferably, the gap between the inner drilling tube and the outer protective tube is filled with a lubricating medium to prevent jamming during core extraction.

[0018] Preferably, the outer protective cylinder is provided with at least one injection hole for injecting lubricating medium.

[0019] On the other hand, the present invention provides a drilling method in fractured surrounding rock of a tunnel, using the above-mentioned drilling device, and the drilling method includes the following steps:

[0020] Equipment installation and commissioning: The inner drilling cylinder is coaxially installed inside the outer protective cylinder through threaded connection, and the tail of the outer protective cylinder is installed on the rotary power mechanism through the first tail connector;

[0021] Integral drilling: The rotary power mechanism is activated to carry out integral drilling on the broken surrounding rock of the tunnel. Under the limit of the threaded connection and the first tail connector, the inner drilling tube and the outer protective tube rotate synchronously.

[0022] Separation of inner and outer layers, continued drilling: When the overall drilling passes through the fractured rock layer or reaches the set depth, the rotary power mechanism is paused, the first tail connector is removed, the extended drill pipe is connected to the tail of the inner drilling pipe, and the tail of the extended drill pipe is installed on the rotary power mechanism through the second tail connector. Under the drive of the rotary power mechanism, it rotates relative to the outer protective cylinder to continue drilling, thus achieving separation of inner and outer layers and continued drilling.

[0023] Therefore, compared with the prior art, the present invention has the following advantages:

[0024] By employing a double-layered, separable cylindrical structure, the drilling process is divided into two steps: the installation of the protective casing and secondary drilling. The outer protective casing further protects the borehole in fractured rock strata, preventing common problems in conventional drilling methods that result in hole collapse, misalignment, and drill bit jamming due to rock fragmentation. This invention is simple in structure, easy to operate, highly practical, and widely applicable, improving the efficiency and success rate of drilling in fractured rock strata and ensuring the smooth progress of tasks such as anchor bolt installation, deep grouting, and ground stress measurement. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of a drilling device for breaking up surrounding rock in a tunnel, as described in an embodiment of the present invention.

[0026] Figure 2 This is a schematic diagram of the drilling device connected to the first tail connector in this invention.

[0027] Figure 3 This is a schematic diagram of the drilling device connecting to the second tail connector in this invention.

[0028] Figure 4 This is a schematic diagram of the outer protective cylinder structure in an embodiment of the present invention.

[0029] Figure 5 This is a schematic diagram of the inner drilling cylinder structure in an embodiment of the present invention.

[0030] Figure 6 This is a schematic diagram of the extended drill barrel structure in an embodiment of the present invention.

[0031] Figure 7 This is a schematic diagram of the tail connection device in an embodiment of the present invention, wherein... Figure 7 A in the diagram is the first tail connector. Figure 7 B in the diagram is the second tail connector. Figure 7 C in the diagram is a schematic of the extension rod.

[0032] Figure 8 This is a schematic diagram of the process for drilling through fractured surrounding rock in an embodiment of the present invention, wherein, Figure 8 A in the diagram represents the overall drilling process. Figure 8 Figure B shows a schematic diagram of the overall drilling reaching the set depth. Figure 8 C represents a schematic diagram of the connection between the inner drilling barrel and the extended drill barrel, as well as the second tail connector, after integral drilling. Figure 8 D in the diagram is a schematic diagram of the extended drill pipe connecting to the inner drilling pipe for continued drilling; Figure 8 E in the diagram represents the borehole formed after the inner drilling tube reverses and exits.

[0033] Figure 9 This is a schematic diagram of a drill bit in an embodiment of the present invention.

[0034] 1-Tunnel fractured surrounding rock, 11-Shallow and medium-depth fractured surrounding rock, 12-Deep intact surrounding rock, 2-Drilling device, 21-Outer protective cylinder, 211-First internal thread, 22-Inner drilling cylinder, 221-First external thread, 222-Second internal thread, 23-Extended drill cylinder, 231-First connecting thread, 232-Second connecting thread, 3-Rotary power mechanism, 4-Drill hole, 51-First tail connector, 511-First end cap, 512-First boss, 513-Connecting hole, 52-Second tail connector, 521-Second end cap, 522-Second boss, 53-Extended rod, 6-Injection hole, 7-Drill bit, 71-First column, 711-Second external thread, 72-Second column, 721-Third external thread, 73-Drilling part. Detailed Implementation

[0035] The following examples, in conjunction with the appendix, illustrate the concepts. Figure 1-9 The technical features, objectives, and effects of the present invention will be further described in detail below.

[0036] Example 1, such as Figures 1 to 7 As shown, the present invention provides a drilling device 2 for tunnel rock breaking 1, comprising:

[0037] The outer protective cylinder 21 can be detachably mounted on the rotary power mechanism via the first tail connector 51, and rotates under the drive of the rotary power mechanism 3 to perform drilling.

[0038] The inner drilling barrel 22 is coaxially installed inside the outer protective barrel 21 via threaded connection. The front end of the inner drilling barrel 22 is coaxially equipped with a drill bit 7 for drilling.

[0039] The extended drill barrel 23 has its front end detachably connected to the end of the inner drilling barrel 22, and its tail end detachably mounted on the rotary power mechanism via the second tail connector 52. Under the power provided by the rotary power mechanism 3, the inner drilling barrel 22 is driven to drill.

[0040] When the outer protective casing 21 is connected to the rotary power mechanism via the first tail connector 51, the inner drilling casing 22 and the outer protective casing 21 are drilled together as a whole. When the first tail connector 51 is removed and the inner drilling casing 22 is connected to the rotary power mechanism via the extended drill casing 23 and the second tail connector 52, the rotary power mechanism can drive the inner drilling casing 22 to rotate relative to the outer protective casing 21, thereby achieving secondary drilling under the protection of the outer protective casing 21.

[0041] like Figure 8 As shown, the method for drilling a hole 4 through fractured surrounding rock using the above-mentioned drilling device 2 is as follows:

[0042] Equipment installation and commissioning: such as Figure 8 As shown in Figure A, the inner drilling cylinder 22 is coaxially installed inside the outer protective cylinder 21 through a threaded connection, and the tail of the outer protective cylinder 21 is installed on the rotary power mechanism through the first tail connector 51. The tunnel fractured surrounding rock 1 includes shallow and medium-depth fractured surrounding rock 11 and deep intact surrounding rock 12.

[0043] Overall drilling: The rotary power mechanism 3 is turned on to carry out overall drilling on the broken surrounding rock 1 of the tunnel. Under the limit of the threaded connection and the first tail connector 51, the inner drilling tube 22 and the outer protective tube 21 rotate and drill synchronously.

[0044] Separate internal and external layers and continue drilling: When the entire drill passes through the shallow and medium-depth fractured surrounding rock 11 and reaches the deep, intact surrounding rock 12, as follows... Figure 8 As shown in Figure B, pause the rotating power mechanism 3, remove the first tail connector 51, connect the extended drill barrel 23 to the tail of the inner drilling barrel 22, and install the tail of the extended drill barrel 23 onto the rotating power mechanism via the second tail connector 52, as shown. Figure 8 As shown in Figure C, driven by the rotary power mechanism 3, the material rotates relative to the outer protective cylinder 21 to continue drilling, achieving separation of the inner and outer layers and allowing drilling to continue. Figure 8 As shown in D, the final drill hole 4 is obtained as shown in Figure 4. Figure 8 As shown in E.

[0045] This invention involves drilling a borehole 4 through fractured surrounding rock by connecting the inner and outer drill tubes (the outer protective tube 21 is actually the drill tube) as a whole. After passing through the fractured surrounding rock, the inner drill tube 22 is connected to the rotary power mechanism through the extended drill tube 23 and the second tail connector 52, thus separating the inner and outer drill tubes. The outer protective tube 21 remains in the shallow and medium-depth fractured surrounding rock as a protective tube, while the inner drill tube 22 continues to drill under the power transmitted by the extended drill tube 23. This can effectively avoid the collapse of the already formed hole in the fractured surrounding rock area caused by the vibration of the borehole 4 during the process of drilling deeper into the borehole 4, thereby avoiding the failure of the borehole 4 such as the drill bit 7 getting stuck.

[0046] It should be noted that the rotary power mechanism 3 can be any drilling machine in the prior art, such as a motor with a feed mechanism, and there are no restrictions in this invention.

[0047] It should be noted that, generally speaking, the drill bit 7 needs to be equipped with cooling and slag removal mechanisms. These are not improvements of the present invention and can be achieved using existing technology. The slag removal pipe and cooling water pipe can be extended from the inner drilling barrel 22 and the extended drilling barrel 23 to the outside. For example, the pipe hole can be started in the middle of the first tail connector 51 to avoid interference between the slag removal pipe and the cooling water pipe and the rotation of the inner drilling barrel 22.

[0048] As a preferred embodiment, such as Figure 1 , 2 As shown in Figure 4, the inner wall of the outer protective cylinder 21 is provided with a first internal thread 211 with a full thread, and the outer wall of the inner drilling cylinder 22 is provided with a corresponding first external thread 221 of the first internal thread 211. During installation, the inner drilling cylinder 22 can be screwed into the outer protective cylinder 21 from the tail end through the thread. Since the inner wall of the outer protective cylinder 21 is provided with a full thread, the inner drilling cylinder 22 can continue to be screwed in when separated, thereby realizing the separation and secondary drilling functions.

[0049] As an improved embodiment, during integral drilling, the drilling end of the inner drilling casing 22 is recessed to a certain extent relative to the outer protective casing 21, which facilitates the installation of the drill bit 7, such as... Figure 9 The drill bit 7 comprises a first column 71, a second column 72, and a tapered drilling section 73. The first column 71 has a second external thread 711 on its outer periphery that connects to the front end of the inner drilling cylinder 22, and the inner wall of the front end of the inner drilling cylinder 22 has a corresponding second internal thread 222. The second column 72 has a larger diameter than the first column 71, and the outer periphery of the second column 72 has a third external thread 721 that mates with the first internal thread 211 inside the front end of the outer protective cylinder 21. By designing this unique structure for the drill bit 7 body, the gap between the drill bit 7 and the outer protective cylinder 21 is small enough during overall drilling, reducing the entry of debris into the gap between the inner drilling cylinder 22 and the outer protective cylinder 21, and preventing jamming during separation. At the same time, when drilling continues after separation, the drill bit 7 can also follow the inner drilling cylinder 22 to drill. It also does not affect the exit of the drill bit 7 from the outer protective cylinder 21 after the drilling 4 is completed.

[0050] As an improved embodiment, a high-strength alloy wear-resistant layer is provided on the surface of the drilling section 73 of the drill bit 7 to further improve the hardness, strength and wear resistance of the drill bit 7.

[0051] It should be noted that, in order to ensure the implementation of drilling after overall drilling and separation, the tightening direction between the first column 71 on the drill bit 7 and the inner drilling tube 22 is the same as the continuing drilling direction of the inner drilling tube 22; to prevent the drill bit 7 from falling off during the continued drilling process.

[0052] It should be noted that the direction of rotation of the connecting threads of the inner drilling tube 22 and the outer protective tube 21 is not restricted. When the rotating power mechanism 3 carries the outer protective tube 21 for drilling, the outer protective tube 21 is the driving component and the inner drilling tube 22 is the following component. Under the limitation of the reaction force of the first tail connector 31 and the front rock layer, the inner drilling tube 22 cannot undergo relative axial movement. That is to say, during the overall drilling, the inner drilling tube 22 has very good following performance. When the inner and outer layers are separated, the inner drilling tube 22 is the driving component, while the outer protective tube 21 is squeezed and stuck in the rock layer by the friction of the broken surrounding rock. Therefore, by rotating the inner drilling tube 22, it can be easily separated from the outer protective tube 21 for continued drilling.

[0053] As an improved embodiment, such as Figure 7 As shown, the first tail connector 51 is the first end cap 511, which is connected to the tail of the outer protective cylinder 21 by a threaded connection.

[0054] like Figure 6 As shown, the extended drill barrel 23 is provided with a first connecting thread 231 at one end and a second connecting thread 232 at the other end. The extended drill barrel 23 is connected to the tail of the inner drilling barrel 22 through the first connecting thread 231. The second tail connector 52 is a second end cap 521, which is connected to the second connecting thread 232 of the extended drill barrel 23 through a threaded engagement.

[0055] It should be noted that since the first end cover 511 and the second end cover 521 are installed alternately, they will not interfere with each other. Therefore, the first end cover 511 and the second end cover 521 can be either solid end covers or hollow end covers in the middle without being affected. Generally speaking, in order to set up slag discharge and cooling water pipes, a through hole should be set in the middle of the first end cover 511 and the second end cover 521.

[0056] As an improved embodiment, such as Figure 7 As shown, the first end cover 511 and the second end cover 521 are respectively provided with connecting parts that are connected to the rotary power mechanism. The connecting parts include connecting holes 513 provided on the first end cover 511 and the second end cover 521 and an extension rod 53 connected to the connecting holes 513. The connecting parts can be conveniently connected to the drill shaft or similar mechanism of the rotary power mechanism 3.

[0057] It should be noted that the first end cap 511 and the second end cap 521 are similar in shape but different in size. Taking the first end cap 511 as an example, as follows... Figure 7The first end cap 511 is a circular end cap with a first boss 512 on one side and a connecting plate on the other side. The connecting plate has a connecting hole 513. The first boss 512 has external threads around its perimeter, which can be threadedly connected to the internal threads at the tail of the outer protective cylinder 21. Of course, in this embodiment, the thread direction connecting the first end cap 511 and the outer protective cylinder 21 should be opposite to the overall drilling direction, so that the first end cap 511 and the outer protective cylinder 21 will not loosen during the drilling process.

[0058] It is foreseeable that, since the first end cap 511 needs to be connected to the tail end of the outer protective tube 21, a certain space needs to be occupied at the tail end of the outer protective tube 21. Therefore, in order to ensure that the drilling end of the inner drilling tube 22 is roughly flush with the outer protective tube 21, the length of the inner drilling tube 22 should be slightly shorter than that of the outer protective tube 21.

[0059] It should be noted that, as Figure 7 As shown, the second end cap 521 is similar in shape to the first end cap 511. Since it needs to be connected to the inner drilling cylinder 22, the diameter of the second boss on it is smaller than that of the first boss 512 on the first end cap 511. The thread direction between the second boss and the inner drilling cylinder 22 is selected according to the rotation direction of the inner drilling cylinder 22 during secondary drilling.

[0060] As an improved embodiment, to prevent the inner drilling barrel 22 from jamming during continued drilling or withdrawal, the gap between the inner drilling barrel 22 and the outer protective barrel 21 is filled with a lubricating medium to prevent jamming during core extraction. The lubricating medium serves two purposes: direct lubrication and preventing debris from entering the gap between the inner and outer barrels during drilling, thus preventing jamming. The lubricating medium can be lubricating oil or grease, although grease is the most convenient in practical engineering.

[0061] As an improved embodiment, the outer protective sleeve 21 is provided with at least one injection hole 6 for injecting lubricating medium. Injecting lubricating medium through the injection hole 6 is beneficial for filling the lubricating medium completely and greatly reduces the possibility of jamming. The number of injection holes 6 is not limited, for example, there can be one or multiple holes that surround the outer protective sleeve 21.

[0062] As an improved embodiment, the drilling end surface of the outer protective sleeve 21 is provided with a wear-resistant alloy coating to improve the drilling capability of the outer protective sleeve 21 during overall drilling.

[0063] It should be noted that, in order to ensure that the inner drilling barrel 22 can continue to drill and retract smoothly, the second end cap 521 and the inner drilling barrel 22 can be connected by auxiliary connecting parts, such as bolts or screws, in addition to the threaded connection. This prevents the direct threaded connection between the second end cap 521 and the inner drilling barrel 22 from loosening when the inner drilling barrel 22 is reversed and retracted. Similarly, the drill bit 7 and the inner drilling barrel 22 can also be connected by auxiliary connecting parts such as clips or screws to prevent the drill bit 7 from loosening and falling into the borehole 4 when the inner drilling barrel 22 is reversed and retracted.

[0064] The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

Claims

1. A drilling device for breaking surrounding rock in tunnels, characterized in that: include The outer protective cylinder can be detachably mounted on the rotary power mechanism via the first tail connector, and rotates under the drive of the rotary power mechanism to perform drilling. The inner drilling tube is coaxially installed inside the outer protective tube via a threaded connection, and the front end of the inner drilling tube is equipped with a drill bit for drilling. The extended drill barrel has its front end detachably connected to the end of the inner drilling barrel, and its tail end detachably mounted on the rotary power mechanism via a second tail connector. With the power provided by the rotary power mechanism, the inner drilling barrel is driven to drill. When the outer protective casing is connected to the rotary power mechanism via the first tail connector, the inner drilling casing and the outer protective casing are drilled together as a whole. When the first tail connector is removed and the inner drilling casing is connected to the rotary power mechanism via the extended drill casing and the second tail connector, the rotary power mechanism can drive the inner drilling casing to rotate relative to the outer protective casing, thus achieving secondary drilling under the protection of the outer protective casing. The outer protective cylinder has a full thread on its inner wall, and the inner drilling cylinder has a corresponding full thread on its outer side. By selecting the thread direction between the inner drilling tube and the outer protective tube, the rotation direction of the secondary drilling is the same as the rotation direction of the overall drilling. The first tail connector is a first end cap, which is connected to the tail of the outer protective cylinder by a threaded connection. The extended drill barrel is connected to the tail end of the inner drilling barrel via a threaded connection; the second tail end connector is a second end cap, which is connected to the tail end of the inner drilling barrel via a threaded connection. The first end cover and the second end cover are respectively provided with connecting parts that are connected to the rotary power mechanism.

2. The drilling device according to claim 1, characterized in that: The connector includes a connecting hole provided on the first end cap and the second end cap, and an extension rod connected to the connecting hole.

3. The drilling device according to claim 1, characterized in that: The gap between the inner drilling tube and the outer protective tube is filled with a lubricating medium to prevent jamming during core extraction.

4. The drilling device according to claim 3, characterized in that: The outer protective cylinder is provided with at least one injection hole for injecting lubricating medium.

5. A drilling method in fractured surrounding rock of a tunnel, using the drilling device described in any one of claims 1-4, characterized in that: The drilling method includes the following steps: Equipment installation and commissioning: The inner drilling cylinder is coaxially installed inside the outer protective cylinder through threaded connection, and the tail of the outer protective cylinder is installed on the rotary power mechanism through the first tail connector; Integral drilling: The rotary power mechanism is activated to carry out integral drilling on the broken surrounding rock of the tunnel. Under the limit of the threaded connection and the first tail connector, the inner drilling tube and the outer protective tube rotate synchronously. Separation of inner and outer layers, continued drilling: When the overall drilling passes through the fractured rock layer or reaches the set depth, the rotary power mechanism is paused, the first tail connector is removed, the extended drill pipe is connected to the tail of the inner drilling pipe, and the tail of the extended drill pipe is installed on the rotary power mechanism through the second tail connector. Under the drive of the rotary power mechanism, it rotates relative to the outer protective cylinder to continue drilling, thus achieving separation of inner and outer layers and continued drilling.

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