Ultra-deep high-precision drill bit and construction technology thereof

Abstract

The invention discloses an ultra-deep high-precision drill bit and a construction technology thereof, and belongs to the technical field of pile foundation construction, the ultra-deep high-precision drill bit comprises a drill bit main body, an isolation hood, a gravity hammer and a strong magnetic block, the isolation hood is installed in the drill bit main body, the isolation hood is fixedly connected with the drill bit main body, the top of the isolation hood is hinged to the gravity hammer, and the bottom of the isolation hood is fixedly connected with the strong magnetic block; the gravity hammer is made of iron materials and filled with lead, and the gravity hammer and the strong magnetic block are limited through attraction. An ultra-deep high-precision drill bit is adopted for construction, and the specific construction steps are as follows: preparation before construction; conventional drill bit downward drilling construction; the ultra-deep high-precision drill bit drills downwards for construction; and performing pore-forming operation. By arranging the gravity hammer and the strong magnetic block, correction force is applied to the drill bit through strong interaction force between the gravity hammer and the strong magnetic block, and drill bit deviation is corrected in time.

Description

Technical Field

[0001] The invention belongs to the technical field of pile foundation construction, and in particular relates to an ultra-deep high-precision drill bit and a construction process thereof. Background Art

[0002] High-pressure jet grouting piles spray cement slurry into the soil layer at high pressure through the slurry channel and nozzle in the drill rod, cut the soil, and fully mix the cement slurry and the in-situ soil. At the same time, the drill rod is rotated and lifted while spraying, thereby forming a high-pressure jet grouting pile. It is often used in fields such as foundation reinforcement and foundation pit water-stopping curtain. Its advantage is that it improves the material utilization rate of in-situ soil, can reinforce the soil layer of a specific depth, and reduce the cost of construction materials to a certain extent. However, before the construction of jet grouting piles, due to the complexity of the stratum, it is generally necessary to carry out the lead hole construction first, that is, first construct a small diameter borehole to the designed depth, and then put the jet grouting drill rod in and lift it for jet grouting. Therefore, the construction accuracy of small diameter boreholes is relatively high, especially the verticality requirement.

[0003] For some monitoring projects, such as the construction of monitoring holes for deep horizontal displacement, the construction of buried acoustic detection pipes, etc., it is still necessary to first construct small-diameter ultra-deep boreholes, and such boreholes still have high requirements for verticality.

[0004] However, for the above-mentioned various processes that require the use of small-diameter holes for construction, the existing drill bit construction process is difficult to meet the design requirements, especially for the case of hard soil layers, or when encountering side boulders during the drilling process, it is difficult to ensure verticality using conventional drill bits and processes. Based on this, the present invention proposes an ultra-deep high-precision drill bit and its construction process. Summary of the invention

[0005] In view of the above technical problems existing in the prior art, the present invention proposes an ultra-deep high-precision drill bit and its construction process, which overcomes the shortcomings of the prior art. By setting a gravity hammer and a strong magnetic block, the strong interaction force between the two is used to construct a correction force on the drill bit. When the drill bit is deflected by external force, the strong magnetic block deviates with the drill bit, and the gravity hammer remains in a vertical state. At this time, the two attract each other, and the strong magnetic block drives the drill bit back to the center; at this time, the lifting force is the same as the dead weight of the drill pipe, and the drill bit does not have any downward pressure. At this time, the drilling speed is slow, and the strong mutual attraction can well correct the drill bit from deflection, and the verticality control is better; by setting an isolation cover and using non-magnetic materials, it is to avoid magnetization or other influences. In addition, in positive circulation construction, the circulating slurry in the drill pipe will disturb the gravity hammer, and adding an isolation cover avoids such a situation.

[0006] In order to achieve the above object, the present invention adopts the following technical solution: An ultra-deep high-precision drill bit and its construction process, comprising a drill bit body, an isolation cover, a gravity hammer, and a strong magnetic block, wherein the isolation cover is installed in the drill bit body, the isolation cover and the drill bit body are connected and fixed, the top of the isolation cover is hinged to the gravity hammer, and the bottom of the isolation cover is connected and fixed to the strong magnetic block; the gravity hammer is made of iron material, filled with lead, and the gravity hammer and the strong magnetic block are limited by gravity; the ultra-deep high-precision drill bit is used for construction, and the specific construction steps are as follows: Step 1: Preparation before construction Check the connection strength between the isolation cover and the drill body, ensure that the distance between the two sides of the gravity hammer and the isolation cover is the same, and that the gravity hammer and the strong magnetic block attract each other; prepare the circulating slurry according to the design requirements; Step 2: Conventional drill bit drilling construction When constructing soft clay with low hardness on the upper part, a conventional drill bit is used for drilling. During the construction process, a verticality detection device is used to measure the verticality of the hole. During the drilling process, a positive circulation process is used. The circulating slurry flows from the drill rod to the soil-breaking interface, and the slag returns to the ground from the gap between the drill rod and the soil. Step 3: Ultra-deep high-precision drill bit drilling construction During the drilling process with a conventional drill bit, if the first verticality test does not meet the design requirements, the conventional drill bit is used to lift the drill again to sweep the hole and test the verticality again. If it still does not meet the design requirements, the conventional drill bit is replaced with an ultra-deep high-precision drill bit, and then the drill rod is lowered to 2-3m above the position with a large verticality deviation. The upper pulling force is controlled to be the same as the overall weight of the drill rod in the borehole, and the drilling is continued at a drilling speed of 2 cm / min-5cm / min. During the drilling process with a conventional drill bit, the overall vibration of the drill rod is large, and the drilling speed is less than 1 cm / min. The conventional drill bit is replaced with an ultra-deep high-precision drill bit, and the pull-up force is controlled to be the same as the overall weight of the drill rod in the borehole, and the drilling is continued at a drilling speed of 0.5 cm / min -1.5 cm / min. Step 4: Hole forming After the entire drilling construction reaches the designed depth, the verticality of the entire pile is tested. The test points are closer than during the construction process. For points that do not meet the verticality requirements, an ultra-deep high-precision drill bit is used to further drill the hole until the designed depth is reached. The circulating slurry is continuously supplied to return large-grained gravel or sand at the bottom of the hole and in the hole to the ground.

[0007] Preferably, the central axis of the gravity hammer coincides with the central axis of the isolation cover, and the distance between the outer edge of the gravity hammer and the inner wall of the isolation cover is 3 cm-5 cm.

[0008] Preferably, the isolation cover is made of carbon fiber, hard alloy, or high-strength polyethylene plate.

[0009] Preferably, the verticality detection mentioned in step 2 and step 3 is performed once every 10m-20m, and the verticality detection mentioned in step 4 is performed once every 5m-10m.

[0010] Beneficial technical effects brought by the present invention: By setting up a gravity hammer and a strong magnetic block, the strong interaction force between the two is used to correct the drill bit. When the drill bit is deflected by external force, the strong magnetic block deviates with the drill bit, and the gravity hammer remains vertical. At this time, the two attract each other, and the strong magnetic block drives the drill bit back to the center. At this time, the lifting force is the same as the weight of the drill pipe, and the drill bit does not have any downward pressure. At this time, the drilling speed is slow, and the strong mutual attraction can well correct the drill bit from deflection, and the verticality control is better. The isolation cover is set and non-magnetic material is used to avoid magnetization or other influences. In addition, in positive circulation construction, the circulating slurry in the drill pipe will disturb the gravity hammer. The addition of the isolation cover avoids such a situation. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 The present invention is a cross-sectional view of an ultra-deep high-precision drill bit and an ultra-deep high-precision drill bit in a construction process thereof.

[0012] Figure 2 It is a cross-sectional view of an ultra-deep high-precision drill bit and a construction process thereof in an inclined state according to the present invention.

[0013] Figure 3 The present invention provides an ultra-deep high-precision drill bit and a top view of the drill bit body in its construction process.

[0014] Among them: 1-drill bit body, 2-isolation cover, 3-gravity hammer, 4-strong magnetic block. DETAILED DESCRIPTION

[0015] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments: Embodiment 1:

[0016] like Figure 1-3 As shown, an ultra-deep high-precision drill bit and its construction process include a drill bit body 1, an isolation cover 2, a gravity hammer 3, and a strong magnetic block 4, wherein the isolation cover 2 is installed in the drill bit body 1, the isolation cover 2 and the drill bit body 1 are connected and fixed, the top of the isolation cover 2 is hinged to the gravity hammer 3, and the bottom of the isolation cover 2 is connected and fixed to the strong magnetic block 4; the gravity hammer 3 is made of iron material, filled with lead, and the gravity hammer 3 and the strong magnetic block 4 are limited by gravity; the ultra-deep high-precision drill bit is used for construction, and the specific construction steps are as follows: Step 1: Preparation before construction Check the connection strength between the isolation cover 2 and the drill body 1, ensure that the distance between the two sides of the gravity hammer 3 and the isolation cover 2 is the same, and the gravity hammer 3 and the strong magnetic block 4 attract each other; prepare the circulating slurry according to the design requirements; Step 2: Conventional drill bit drilling construction When constructing soft clay with low hardness on the upper part, a conventional drill bit is used for drilling. During the construction process, a verticality detection device is used to measure the verticality of the hole. During the drilling process, a positive circulation process is used. The circulating slurry flows from the drill rod to the soil-breaking interface, and the slag returns to the ground from the gap between the drill rod and the soil. Step 3: Ultra-deep high-precision drill bit drilling construction During the drilling process with a conventional drill bit, if the first verticality test does not meet the design requirements, the conventional drill bit is used to lift the drill again to sweep the hole and test the verticality again. If it still does not meet the design requirements, the conventional drill bit is replaced with an ultra-deep high-precision drill bit, and then the drill rod is lowered to 2-3m above the position with a large verticality deviation. The upper pulling force is controlled to be the same as the overall weight of the drill rod in the borehole, and the drilling is continued at a drilling speed of 2 cm / min-5cm / min. During the drilling process with a conventional drill bit, the overall vibration of the drill rod is large, and the drilling speed is less than 1 cm / min. The conventional drill bit is replaced with an ultra-deep high-precision drill bit, and the pull-up force is controlled to be the same as the overall weight of the drill rod in the borehole, and the drilling is continued at a drilling speed of 0.5 cm / min -1.5 cm / min. Step 4: Hole forming After the entire drilling construction reaches the designed depth, the verticality of the entire pile is tested. The test points are closer than during the construction process. For points that do not meet the verticality requirements, an ultra-deep high-precision drill bit is used to further drill the hole until the designed depth is reached. The circulating slurry is continuously supplied to return large-grained gravel or sand at the bottom of the hole and in the hole to the ground.

[0017] Preferably, the central axis of the gravity hammer 3 coincides with the central axis of the isolation cover 2, and the distance between the outer edge of the gravity hammer 3 and the inner wall of the isolation cover 2 is 3 cm-5 cm.

[0018] Preferably, the isolation cover 2 is made of carbon fiber, hard alloy, or high-strength polyethylene plate.

[0019] Preferably, the verticality detection mentioned in step 2 and step 3 is performed once every 10m-20m, and the verticality detection mentioned in step 4 is performed once every 5m-10m. Embodiment 2:

[0020] like Figure 1-3As shown, an ultra-deep high-precision drill bit and its construction process include a drill bit body 1, an isolation cover 2, a gravity hammer 3, and a strong magnetic block 4, wherein the isolation cover 2 is installed in the drill bit body 1, the isolation cover 2 and the drill bit body 1 are connected and fixed, the top of the isolation cover 2 is hinged to the gravity hammer 3, and the bottom of the isolation cover 2 is connected and fixed to the strong magnetic block 4; the gravity hammer 3 is made of iron and filled with lead, and the gravity hammer 3 and the strong magnetic block 4 are limited by gravity; the ultra-deep high-precision drill bit is used for construction, and the specific construction steps are as follows: the outside of the gravity hammer 3 is made of iron in order to attract the strong magnetic block 4, but in order to increase the overall weight of the gravity hammer 3, the inside is replaced with lead, which does not delay the attraction and increases the weight.

[0021] Step 1: Preparation before construction Check the connection strength between the isolation cover 2 and the drill body 1, ensure that the distances between the two sides of the gravity hammer 3 and the isolation cover 2 are the same, and the gravity hammer 3 and the strong magnetic block 4 attract each other; prepare the circulating slurry according to the design requirements; the isolation cover 2 is set and non-magnetic material is used to avoid magnetization or other influences. In addition, during the positive circulation construction, the circulating slurry in the drill pipe will disturb the gravity hammer 3. The addition of the isolation cover 2 avoids such a situation.

[0022] Step 2: Conventional drill bit drilling construction When constructing soft clay with lower hardness on the upper part, a conventional drill bit is used for drilling. During the construction process, a verticality detection device is used to measure the verticality of the hole. A positive circulation process is adopted during the drilling process. The circulating slurry flows from the drill rod to the soil-breaking interface, and the slag returns to the ground from the gap between the drill rod and the soil. The reason for using a conventional drill bit for drilling construction in the first place is that the entire cross-section inside the conventional drill bit is unobstructed, and the slurry has better fluidity. An isolation cover 2 is set in the ultra-deep high-precision drill bit, which reduces the space for slurry circulation.

[0023] Step 3: Ultra-deep high-precision drill bit drilling construction During the drilling process with a conventional drill bit, if the first verticality test does not meet the design requirements, the conventional drill bit is used to lift the drill again to sweep the hole and test the verticality again. If it still does not meet the design requirements, the conventional drill bit is replaced with an ultra-deep high-precision drill bit, and then the drill rod is lowered to 2-3m above the position with a large verticality deviation. The upper pulling force is controlled to be the same as the overall weight of the drill rod in the borehole, and the drilling is continued at a drilling speed of 2 cm / min-5cm / min. During the drilling process with a conventional drill bit, the overall vibration of the drill rod is large, and the drilling speed is less than 1 cm / min. The conventional drill bit is replaced with an ultra-deep high-precision drill bit, and the pull-up force is controlled to be the same as the overall weight of the drill rod in the borehole, and the drilling is continued at a drilling speed of 0.5 cm / min -1.5 cm / min. By setting the gravity hammer 3 and the strong magnetic block 4, the strong interaction force between the two is used to correct the drill bit. When the drill bit is deflected by external force, the strong magnetic block 4 deviates with the drill bit, and the gravity hammer 3 remains in a vertical state. At this time, the two attract each other, and the strong magnetic block 4 drives the drill bit back to the center. At this time, the lifting force is the same as the deadweight of the drill rod, and the drill bit does not have any downward pressure. At this time, the drilling speed is slow. In soft soil, the drilling speed is 2 cm / min-5 cm / min. In hard soil and when there are boulders, the drilling speed is 0.5 cm / min-1.5 cm / min. The strong mutual attraction can well correct the drill bit from deflection, and the verticality control is better. Step 4: Hole forming After the entire drilling construction reaches the designed depth, the verticality of the entire pile is tested. The test points are closer than during the construction process. For points that do not meet the verticality requirements, an ultra-deep high-precision drill bit is used to further drill the hole until the designed depth is reached. The circulating slurry is continuously supplied to return large-grained gravel or sand at the bottom of the hole and in the hole to the ground.

[0024] Preferably, the central axis of the gravity hammer 3 coincides with the central axis of the isolation cover 2, and the distance between the outer edge of the gravity hammer 3 and the inner wall of the isolation cover 2 is 5 cm.

[0025] Preferably, the isolation cover 2 is made of carbon fiber.

[0026] Preferably, the verticality detection mentioned in step 2 and step 3 is performed once every 10 meters, and the verticality detection mentioned in step 4 is performed once every 5 meters. Embodiment 3:

[0027] When drilling to a depth of 20m, a solitary rock is encountered. The solitary rock is not within the entire cross section of the drill pipe, but on one side. Assuming that the solitary rock is on the right side of the drill bit, the drill bit will be blocked by the solitary rock during the drilling process, and the soil on the left side is relatively soft, so the drill bit must be offset to the left during the drilling process, and the verticality must exceed the design value. At this time, an ultra-deep high-precision drill bit is used. When the drill bit deviates to the left, the gravity hammer 3 is still vertically downward. At this time, the gravity hammer 3 attracts the strong magnetic block 4 to return to the center, and the strong magnetic block 4 drives the drill bit to return to the center. At this time, the lifting force is the same as the weight of the drill pipe, the drill bit is not subject to downward pressure at all, and the construction speed is extremely slow. At this time, the drill bit moves in the vertical direction.

[0028] In the description of the present invention, it is necessary to understand that the orientations or positional relationships indicated by terms such as "center", "up", "down", "front", "back", "bottom", "inside" and "outside" are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0029] In the description of the embodiments of the present invention, the term "and / or" refers to and covers any and all possible combinations of one or more of the associated listed items. The term "and / or" is a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in the present invention generally indicates that the associated objects before and after are in an "or" relationship.

[0030] In the description of the embodiments of the present invention, the terms "comprises", "comprising" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the statement "comprising a ..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element. In the absence of further restrictions, an element defined by the statement "comprising a ..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element.

[0031] The above description is only a specific embodiment of the present invention, so that those skilled in the art can understand or implement the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments described herein, but should conform to the widest scope consistent with the principles and novel features disclosed herein.

[0032] Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by technicians in this technical field within the essential scope of the present invention also fall within the protection scope of the present invention.

Claims

1. An ultra-deep high-precision drill bit and its construction process, characterized in that: It includes a drill body, an isolation cover, a gravity hammer, and a strong magnetic block. The isolation cover is installed in the drill body, the isolation cover and the drill body are connected and fixed, the top of the isolation cover is hinged to the gravity hammer, and the bottom of the isolation cover is connected and fixed to the strong magnetic block; the gravity hammer is made of iron and filled with lead. The gravity hammer and the strong magnetic block are limited by gravity; an ultra-deep high-precision drill is used for construction. The specific construction steps are as follows: Step 1: Preparation before construction Check the connection strength between the isolation cover and the drill body, ensure that the distance between the two sides of the gravity hammer and the isolation cover is the same, and that the gravity hammer and the strong magnetic block attract each other; prepare the circulating slurry according to the design requirements; Step 2: Conventional drill bit drilling construction When constructing soft clay with low hardness on the upper part, a conventional drill bit is used for drilling. During the construction process, a verticality detection device is used to measure the verticality of the hole. During the drilling process, a positive circulation process is used. The circulating slurry flows from the drill rod to the soil-breaking interface, and the slag returns to the ground from the gap between the drill rod and the soil. Step 3: Ultra-deep high-precision drill bit drilling construction During the drilling process with a conventional drill bit, if the first verticality test does not meet the design requirements, the conventional drill bit is used to lift the drill again to sweep the hole and test the verticality again. If it still does not meet the design requirements, the conventional drill bit is replaced with an ultra-deep high-precision drill bit, and then the drill rod is lowered to 2-3m above the position with a large verticality deviation. The upper pulling force is controlled to be the same as the overall weight of the drill rod in the borehole, and the drilling is continued at a drilling speed of 2 cm / min-5cm / min. During the drilling process with a conventional drill bit, the overall vibration of the drill rod is large, and the drilling speed is less than 1 cm / min. The conventional drill bit is replaced with an ultra-deep high-precision drill bit, and the pull-up force is controlled to be the same as the overall weight of the drill rod in the borehole, and the drilling is continued at a drilling speed of 0.5 cm / min-1.5 cm / min. Step 4: Hole forming After the entire drilling construction reaches the designed depth, the verticality of the entire pile is tested. The test points are closer than during the construction process. For points that do not meet the verticality requirements, an ultra-deep high-precision drill bit is used to further drill the hole until the designed depth is reached. The circulating slurry is continuously supplied to return large-grained gravel or sand at the bottom of the hole and in the hole to the ground.

2. The ultra-deep high-precision drill bit and the construction process thereof according to claim 1, characterized in that: The central axis of the gravity hammer coincides with the central axis of the isolation cover, and the distance between the outer edge of the gravity hammer and the inner wall of the isolation cover is 3cm-5cm.

3. The ultra-deep high-precision drill bit and the construction process thereof according to claim 1, characterized in that: The isolation cover is made of carbon fiber, hard alloy and high-strength polyethylene plate.

4. The ultra-deep high-precision drill bit and the construction process thereof according to claim 1, characterized in that: The verticality detection mentioned in step 2 and step 3 is detected once every 10m-20m, and the verticality detection mentioned in step 4 is detected once every 5m-10m.

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