Drilling construction method of hard rock rotary excavating diversion hob lower guide reaming barrel drill

Abstract

The invention relates to the technical field of graded reaming construction, and discloses a drilling construction method of a guide reaming barrel drill under a hard rock rotary excavating diversion hob, which comprises the following construction steps: 1) a drill rod is connected with a rotary excavating drilling bucket to drill in a soil layer to form a soil layer hole; (2) a rotary excavating drilling bucket is detached, and a rotary excavating barrel drill is connected to form a guide hole; (3) the rotary excavating drill barrel is detached, and the connecting reaming barrel drill and the lower guide barrel are detached; the reaming barrel drill is provided with a hob drill bit and a flow guide cavity, and the flow guide cavity forms a flow guide inlet and a flow guide outlet; the hole expanding drill barrel performs hole expanding drilling on the guide hole, and the guide hole is provided with a non-expanded section which is not subjected to hole expanding drilling; (4) the guide cylinder is dismantled, a non-expanded section of the reaming cylinder drill is used for reaming drilling till the guide hole is expanded to form a rock stratum hole, and the soil layer hole and the rock stratum hole are communicated up and down to form a pile hole; through staged drilling, accurate positioning of the guide hole, rock crushing of the hob drill bit and slurry circulation optimization of the flow guide cavity, the phenomenon of drill pasting is avoided, efficient reaming drilling is achieved, and the construction efficiency is improved.

Description

Technical Field

[0001] This invention patent relates to the technical field of graded borehole enlargement construction, specifically to a drilling construction method for hard rock rotary drilling with guide roller cutter and guide enlargement tube. Background Technology

[0002] In the field of rock pile hole construction, especially for large-diameter hard rock pile hole construction, the staged hole enlargement process is a common technical means. Its advantage lies in the fact that the hole diameter can be gradually enlarged by using a hole enlarger drill to adapt to different geological conditions, while controlling the stability and accuracy of the drilling process to a certain extent.

[0003] However, existing technologies have significant shortcomings in terms of drilling efficiency for reaming barrel drilling.

[0004] First, in terms of drill bit adaptability, in the existing technology, the drill bit type (cutting teeth or roller cones) of the guide borehole drill is limited in efficiency when drilling in high-strength rock, thus affecting the overall construction efficiency;

[0005] Secondly, in terms of mud circulation and drill cuttings treatment, conventional directional reamer drills are prone to "drill sticking" when the rock strata have high clay mineral content or small rock cuttings particle size. This is because there is no effective mud diversion and drill cuttings discharge mechanism, which makes it impossible to maintain the good working condition of the drill teeth.

[0006] In addition, in terms of the flexibility of hole enlargement methods, the existing hole enlargement methods are relatively simple. During the hole enlargement process, the existing guide hole structure cannot be fully utilized for efficient hole enlargement, which in turn reduces the overall efficiency of hole enlargement. Summary of the Invention

[0007] The purpose of this invention is to provide a drilling method for hard rock rotary drilling with guide roller cutter and under-guided reaming barrel drilling, which aims to solve the problem of low drilling efficiency in the prior art.

[0008] This invention is implemented as follows: a drilling method for hard rock rotary drilling with guide roller cutter and under-guided reaming barrel, comprising the following construction steps:

[0009] 1) The drill rod is connected to the rotary drilling bucket, which is used to drill in the soil until the surface of the rock layer is reached, forming a hole in the soil layer;

[0010] 2) Remove the rotary drilling bucket and connect the drill rod to the rotary drilling rig. The rotary drilling rig drills into the rock strata to form a guide hole located below the soil hole. The diameter of the guide hole is smaller than the diameter of the soil hole.

[0011] 3) Remove the rotary drilling rig and connect the reamer and the lower guide cylinder to the drill rod. The diameter of the reamer is the same as the diameter of the soil hole, and the diameter of the lower guide cylinder is the same as the diameter of the guide hole. The lower guide cylinder is located below the reamer. The bottom of the reamer is provided with multiple roller drill bits, which are arranged at intervals around the reamer.

[0012] The reaming barrel drill has a flow guiding cavity, the hobbing drill bit is arranged at the bottom of the flow guiding cavity, the flow guiding cavity penetrates the bottom of the reaming barrel to form a flow guiding inlet, and the flow guiding cavity penetrates the top of the reaming barrel to form a flow guiding outlet;

[0013] The reaming drill barrel reams the guide hole in the rock strata, and the lower guide cylinder moves synchronously along the guide hole until the lower guide cylinder moves to the bottom of the guide hole, and the guide hole has an unreamed section that has not been drilled.

[0014] During the process of the borehole enlargement drill in the rock strata, the mud enters the guide cavity through the guide inlet and is then sprayed upward from the guide outlet.

[0015] 4) Remove the lower guide cylinder and use the unexpanded section of the reaming cylinder to drill the reaming hole until the bottom of the guide hole is reached. The guide hole is expanded to form a rock layer hole. The diameter of the rock layer hole is the same as that of the soil layer hole. The soil layer hole and the rock layer hole are connected vertically to form a pile hole.

[0016] Furthermore, in the construction step 1), before the rotary drilling bucket drills into the soil layer, the construction site is compacted and leveled, and a casing is installed in the soil layer; the rotary drilling bucket drills into the casing to form the soil layer hole.

[0017] Furthermore, in construction step 3), during the process of drilling the guide hole using the reamer, the slag in the guide hole is scooped out using the slag-removing drill bucket until the lower guide cylinder moves to the bottom of the guide hole.

[0018] Furthermore, in construction step 3), the bottom of the reaming barrel drill is provided with multiple cutter sets, which are arranged at intervals around the circumference of the reaming barrel drill; each cutter set includes multiple cutter bits, and the diameter distance between the multiple cutter bits of the cutter set and the center of the reaming barrel drill is different.

[0019] Furthermore, in construction step 3), along the arrangement direction of the multiple roller drill bits of the roller cutter group, the diameter distance between the center of the multiple roller drill cylinders of the roller cutter group and the center of the reaming cylinder gradually decreases or increases.

[0020] Furthermore, in construction step 3), the reaming cylinder surrounds an inner cavity, and an upper connecting cylinder is provided in the inner cavity; the top of the lower guide cylinder is provided with a lower connecting cylinder that is detachably connected to the upper connecting cylinder.

[0021] The upper connecting cylinder is inserted into the lower connecting cylinder and is connected to the lower connecting cylinder as a whole. The lower guide cylinder is located below the reaming cylinder drill.

[0022] Furthermore, in construction step 3), the upper connecting cylinder is provided with multiple upper through holes, which are arranged around the circumference of the upper connecting cylinder at intervals; the lower connecting cylinder is provided with multiple lower through holes, which are arranged around the circumference of the lower connecting cylinder at intervals; a positioning block is protruding from the outer periphery of the upper connecting cylinder, and a positioning groove with a top opening is provided on the lower connecting cylinder.

[0023] When the upper connecting cylinder is inserted into the lower connecting cylinder, the positioning block is embedded in the positioning groove through the top opening. The multiple upper through holes are respectively aligned with the multiple lower through holes. Bolts are inserted into the lower through holes, and the bolts pass through the upper through holes simultaneously, fixing the upper connecting cylinder and the lower connecting cylinder relative to each other.

[0024] Furthermore, in construction step 3), the reaming cylinder includes an inner casing and an outer casing surrounding the outer periphery of the inner casing. The inner casing encloses and forms the inner cavity, and the outer casing and the inner casing form the flow guide cavity.

[0025] The bottom of the flow guiding cavity is covered by an annular bottom plate, and multiple rotary drill bits are disposed on the bottom plate, with multiple flow guiding inlets formed on the bottom plate; the top of the reaming tube drill is provided with a top plate, which covers the top of the inner cavity and the top of the flow guiding cavity, with multiple flow guiding outlets formed on the top plate, and multiple pressure relief holes provided in the top plate, with the multiple pressure relief holes communicating with the top of the inner cavity.

[0026] Furthermore, in construction step 3), the flow guiding cavity is provided with multiple flow guiding cylinders, which are arranged to extend along the axial direction of the reaming cylinder drill. The bottom of the flow guiding cylinder abuts against the bottom plate and communicates with the flow guiding inlet, and the top of the flow guiding cylinder abuts against the top plate and communicates with the flow guiding outlet.

[0027] The top plate is provided with multiple guide covers, and the multiple guide covers are respectively provided with multiple flow outlets; the guide covers enclose to form a lateral cavity, the bottom of the lateral cavity is connected to the flow outlet, the lateral cavity forms a lateral opening, and the lateral opening is arranged opposite to the rotation direction of the reaming drill; along the direction from the flow outlet to the lateral opening, the height of the lateral cavity gradually increases;

[0028] In construction steps 3 and 4), during the process of the reaming drill in the guide hole, the mud enters the guide tube through the guide inlet and is then discharged into the lateral cavity through the guide outlet. The mud is blocked by the top of the guide cover and sprayed out toward the lateral opening.

[0029] Furthermore, in construction step 3), the top plate has a bottom surface located at the bottom of the lateral cavity, and the bottom surface is arranged downwards along the direction from the guide outlet to the lateral opening;

[0030] Multiple elastic strips are formed on the bottom surface. Along the direction from the flow outlet to the lateral opening, the multiple elastic strips are arranged sequentially at intervals, and the elastic strips are arranged to extend laterally along the lateral cavity. Along the direction from bottom to top, the elastic strips are arranged inclined toward the lateral opening, and there is an elastic interval between adjacent elastic strips.

[0031] In construction steps 3 and 4), during the process of the reaming drill in the guide hole, the mud discharged from the guide outlet flows toward the lateral opening, and the multiple elastic strips are pressed and swing back and forth, and the multiple elastic strips restrict the mud from flowing in the opposite direction toward the guide outlet.

[0032] Compared with the prior art, the hard rock rotary drilling guide cutter under-guided reaming barrel drilling construction method provided by the present invention can significantly improve the drilling efficiency of reaming barrel drilling through a staged drilling method. First, the rotary drilling bucket is used to drill into the soil layer to form a soil layer hole, avoiding the efficiency loss caused by using unsuitable drilling tools in different strata.

[0033] Secondly, a pilot hole is drilled in the rock strata to provide precise guidance for subsequent hole enlargement, reducing construction delays caused by hole deviation. Furthermore, during the hole enlargement stage, a combination of a reamer and a lower pilot tube is used. By combining the high-efficiency breaking capacity of the cutter bit and the optimized mud circulation of the guide cavity, efficient hole enlargement of the pilot hole is achieved. Under the synergistic effect of the cutter bit and the guide cavity, it is ensured that the mud can carry the rock cuttings out in time, avoiding the "drill blockage" phenomenon and significantly improving the drilling rate.

[0034] In addition, the step-by-step hole enlargement method makes full use of the structural characteristics of the guide hole, which improves the flexibility and adaptability of hole enlargement. Finally, by removing the lower guide cylinder and using the un-enlarged section drilled by the hole enlarger cylinder, the hole is enlarged until a rock hole with the same diameter as the soil hole is formed, realizing the vertical connection between the soil hole and the rock hole and forming a complete pile hole. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the drilling construction method of the hard rock rotary drilling guide roller cutter under guide reaming tube provided by the present invention;

[0036] Figure 2 This is a three-dimensional schematic diagram of the installation state of the reaming tube drill provided by the present invention;

[0037] Figure 3 This is a three-dimensional schematic diagram of the disassembled state of the reaming tube drill provided by the present invention;

[0038] Figure 4 This is a simplified structural diagram of the flow guiding cavity provided by the present invention;

[0039] In the figure: 100, 101, 102, 103, 104;

[0040] Lower guide cylinder 200, upper connecting cylinder 201, upper through hole 202, lower connecting cylinder 203, lower through hole 204;

[0041] Inner cylinder 300, outer cylinder 301, guide cover 302, lateral cavity 303, lateral opening 304, elastic strip 305, elastic interval 306. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0043] The implementation of the present invention is described in detail below with reference to specific embodiments.

[0044] The same or similar numbers in the drawings of this embodiment correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", etc. indicate the orientation or position relationship, they are based on the orientation or position relationship shown in the drawings. This 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 operate in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting this patent. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0045] Reference Figure 1-4 The figure shows a preferred embodiment of the present invention.

[0046] The drilling method for rotary drilling with guide roller cutter under guide and reaming barrel in hard rock includes the following construction steps:

[0047] 1) The drill rod is connected to the rotary drilling bucket, which is used to drill into the soil layer until the surface of the rock layer is reached, forming a hole in the soil layer;

[0048] 2) Remove the rotary drilling bucket and connect the drill rod to the rotary drilling rig. The rotary drilling rig drills into the rock strata to form a guide hole located below the soil hole. The diameter of the guide hole is smaller than the diameter of the soil hole.

[0049] 3) Remove the rotary drilling rig and connect the reamer 100 and the lower guide cylinder 200 to the drill rod. The diameter of the reamer 100 is the same as the diameter of the soil hole, and the diameter of the lower guide cylinder 200 is the same as the diameter of the guide hole. The lower guide cylinder 200 is located below the reamer 100. The bottom of the reamer 100 is provided with multiple roller drill bits 101, which are arranged at intervals around the circumference of the reamer 100.

[0050] The reaming barrel drill 100 has a flow guide cavity 102, and the hobbing drill bit 101 is arranged at the bottom of the flow guide cavity 102. The flow guide cavity 102 penetrates the bottom of the reaming barrel to form a flow guide inlet, and the flow guide cavity 102 penetrates the top of the reaming barrel to form a flow guide outlet 103.

[0051] The reaming drill pipe reams the pilot hole in the rock strata, and the lower guide cylinder 200 moves synchronously along the pilot hole until the lower guide cylinder 200 moves to the bottom of the pilot hole, and the pilot hole has an unreamed section that has not been drilled.

[0052] During the process of borehole enlargement drilling 100 in rock formation, the mud enters the guide cavity 102 through the guide inlet and is then sprayed upward from the guide outlet 103.

[0053] 4) Remove the lower guide cylinder 200, and use the reamer to drill the unreamed section of the reamer 100 until the bottom of the guide hole is reached. The guide hole is reamed to form a rock layer hole. The diameter of the rock layer hole is the same as that of the soil layer hole. The soil layer hole and the rock layer hole are connected vertically to form a pile hole.

[0054] The above-mentioned hard rock rotary drilling guide cutter under guide reaming tube drilling construction method can significantly improve the drilling efficiency of reaming tube drilling by using a staged drilling method. First, the rotary drilling bucket is used to drill into the soil layer to form a soil layer hole, avoiding the efficiency loss caused by using unsuitable drilling tools in different strata.

[0055] Secondly, a pilot hole is drilled in the rock strata to provide precise guidance for subsequent hole enlargement, reducing construction delays caused by hole deviation. Furthermore, during the hole enlargement stage, a combination of the enlargement tube drill 100 and the lower guide tube 200 is used. Combined with the efficient breaking capacity of the roller drill bit 101 and the optimized mud circulation of the guide cavity 102, efficient hole enlargement of the pilot hole is achieved. Under the synergistic effect of the roller drill bit 101 and the guide cavity 102, it is ensured that the mud can carry the rock cuttings out in time, avoiding the "drill blockage" phenomenon and significantly improving the drilling rate.

[0056] In addition, the step-by-step hole enlargement method makes full use of the structural characteristics of the guide hole, which improves the flexibility and adaptability of hole enlargement. Finally, by removing the lower guide cylinder 200 and using the unenlarged section of the hole enlargement cylinder drill 100, the hole is enlarged until a rock hole with the same diameter as the soil hole is formed, realizing the vertical connection between the soil hole and the rock hole and forming a complete pile hole.

[0057] In this embodiment, in construction step 1), before the rotary drilling bucket drills into the soil layer, the construction site is compacted and leveled, and a casing is installed in the soil layer; the rotary drilling bucket drills into the casing to form a hole in the soil layer.

[0058] By compacting and leveling the site and lowering the casing, a stable working environment can be provided for the rotary drilling bucket before drilling, reducing construction interruptions caused by uneven ground or soil collapse during drilling, thereby improving drilling efficiency.

[0059] In this embodiment, during construction step 3), when the reamer 100 is used to ream the hole in the guide hole, the slag in the guide hole is scooped out by the slag-removing drill bucket until the lower guide cylinder 200 moves to the bottom of the guide hole.

[0060] The slag-removing drill bucket can promptly clean the slag in the guide hole, preventing slag accumulation from hindering the advance of the reaming barrel drill 100, reducing drilling stagnation caused by slag, and improving the efficiency of reaming drilling.

[0061] In this embodiment, in construction step 3), the bottom of the reaming barrel drill 100 is provided with multiple cutter sets, which are arranged around the reaming barrel drill 100 at intervals in the circumference; the cutter set includes multiple cutter bits 101, and the diameter distance between the multiple cutter bits 101 of the cutter set and the center of the reaming barrel drill 100 is different.

[0062] By setting up multiple cutter sets and cutter bits 101 with different diameters, a multi-stage crushing effect can be formed during hole reaming, increasing the contact area with the rock strata, enhancing the crushing efficiency, and thus significantly improving the drilling efficiency of the hole reaming drill 100.

[0063] In this embodiment, during construction step 3), along the arrangement direction of the multiple roller drill bits 101 of the roller cutter group, the diameter distance between the multiple roller drill cylinders of the roller cutter group and the center of the reaming cylinder drill 100 gradually decreases or increases.

[0064] This allows the reamer drill 100 to gradually adapt to changes in hole diameter during drilling, reducing drilling resistance and improving the smoothness and efficiency of the reaming process.

[0065] In this embodiment, in construction step 3), the reaming cylinder drill 100 surrounds and forms an inner cavity, and an upper connecting cylinder 201 is provided in the inner cavity; the top of the lower guide cylinder 200 is provided with a lower connecting cylinder 203 that is detachably connected to the upper connecting cylinder 201.

[0066] The upper connecting cylinder 201 is inserted into the lower connecting cylinder 203 and is connected to the lower connecting cylinder 203 as a whole. The lower guide cylinder 200 is located below the reaming cylinder drill 100.

[0067] The detachable connection design between the upper connecting cylinder 201 and the lower connecting cylinder 203 facilitates quick disassembly and replacement of the lower guide cylinder 200, reducing construction downtime caused by component replacement and improving construction efficiency.

[0068] In this embodiment, in construction step 3), the upper connecting cylinder 201 is provided with multiple upper through holes 202, which are arranged around the upper connecting cylinder 201 at intervals in the circumference. The lower connecting cylinder 203 is provided with multiple lower through holes 204, which are arranged around the lower connecting cylinder 203 at intervals in the circumference. The upper connecting cylinder 201 is provided with a positioning block protruding from its outer periphery, and the lower connecting cylinder 203 is provided with a positioning groove with a top opening.

[0069] When the upper connecting cylinder 201 is inserted into the lower connecting cylinder 203, the positioning block is embedded in the positioning groove through the top opening. Multiple upper through holes 202 are respectively aligned with multiple lower through holes 204. Bolts are inserted into the lower through holes 204, and the bolts pass through the upper through holes 202 simultaneously, fixing the upper connecting cylinder 201 and the lower connecting cylinder 203 relative to each other.

[0070] By using positioning and bolt fixing methods, the connection between the upper connecting cylinder 201 and the lower connecting cylinder 203 is ensured to be accurate and firm, reducing the error adjustment time that may occur during the connection process, improving connection efficiency, and providing a guarantee for quick replacement of parts.

[0071] In this embodiment, in construction step 3), the reaming cylinder drill 100 includes an inner cylinder 300 and an outer cylinder 301 surrounding the outer periphery of the inner cylinder 300. The inner cylinder 300 encloses to form an inner cavity, and a flow guide cavity 102 is formed between the outer cylinder 301 and the inner cylinder 300.

[0072] The bottom of the flow guiding cavity 102 is covered by an annular bottom plate, and multiple rotary drill bits 101 are disposed on the bottom plate, with multiple flow guiding inlets formed on the bottom plate; the top of the reaming tube drill 100 is provided with a top plate, which covers the top of the inner cavity and the top of the flow guiding cavity 102, with multiple flow guiding outlets 103 formed on the top plate, and multiple pressure relief holes are provided in the top plate, with the multiple pressure relief holes communicating with the top of the inner cavity.

[0073] By setting up the flow guide cavity 102 formed by the inner cylinder 300 and the outer cylinder 301 and the pressure relief hole, the mud can be effectively guided and the pressure can be regulated to avoid the impact of excessive mud pressure on drilling, while providing a stable mud circulation environment for the rotary drill bit 101.

[0074] In this embodiment, in construction step 3), the flow guiding cavity 102 is provided with a plurality of flow guiding cylinders 104. The flow guiding cylinders 104 are arranged to extend along the axial direction of the reaming cylinder drill 100. The bottom of the flow guiding cylinder 104 abuts against the bottom plate and communicates with the flow guiding inlet. The top of the flow guiding cylinder 104 abuts against the top plate and communicates with the flow guiding outlet 103.

[0075] The top plate is provided with multiple guide covers 302, and the multiple guide covers 302 are respectively provided with multiple flow outlets 103; the guide covers 302 enclose to form a lateral cavity 303, the bottom of the lateral cavity 303 is connected to the flow outlet 103, the lateral cavity 303 forms a lateral opening 304, and the lateral opening 304 is arranged opposite to the rotation direction of the reaming tube drill 100; along the direction from the flow outlet 103 to the lateral opening 304, the height of the lateral cavity 303 gradually increases;

[0076] In construction steps 3 and 4), during the process of the reaming drill 100 reaming in the guide hole, the mud enters the guide tube 104 through the guide inlet and is then discharged to the lateral cavity 303 through the guide outlet 103. The mud is blocked by the top of the guide cover 302 and sprayed out toward the lateral opening 304.

[0077] The guide tube 104 and guide shield 302 allow the drilling mud to rise orderly along the guide tube 104 and change its flow direction through the guide shield 302, finally being ejected from the lateral opening 304. Since the lateral opening 304 is opposite to the rotation direction of the reamer 100, the reaction force generated when the drilling mud is ejected in the opposite direction can enhance the rotational drive of the reamer 100, thereby effectively improving drilling efficiency.

[0078] In this embodiment, in construction step 3), the top plate has a bottom surface located at the bottom of the lateral cavity 303, and is arranged with the bottom surface facing downward along the direction from the guide outlet 103 to the lateral opening 304.

[0079] Multiple elastic strips 305 are formed on the bottom surface. Along the direction from the flow outlet 103 to the lateral opening 304, the multiple elastic strips 305 are arranged sequentially at intervals, and the elastic strips 305 are arranged to extend laterally along the lateral cavity 303. Along the direction from bottom to top, the elastic strips 305 are arranged inclined toward the lateral opening 304, and there is an elastic interval 306 between adjacent elastic strips 305.

[0080] In construction steps 3 and 4), during the process of the reaming drill 100 reaming in the guide hole, the mud discharged from the guide outlet 103 flows toward the lateral opening 304, and multiple elastic strips 305 are pressed and swing back and forth, and multiple elastic strips 305 restrict the mud from flowing in the opposite direction toward the guide outlet 103.

[0081] The inclined bottom surface and elastic strip 305 can buffer and rectify the flow of mud, avoiding excessive pressure on the guide outlet 103 caused by the impact of mud. At the same time, the swing of the elastic strip restricts the reverse flow of mud, reducing the risk of mud clogging the guide outlet 103, improving the unidirectionality and stability of mud flow, thereby improving drilling efficiency.

[0082] The following will provide a specific, clear, and complete description of the above-mentioned hard rock rotary drilling with guide roller cutter under guide and reaming barrel drilling method in practical application, so as to make the implementation process of the hard rock rotary drilling with guide roller cutter under guide and reaming barrel drilling method easier to understand.

[0083] Hard rock rotary drilling with guide roller cutter and under-guide reamer drilling method:

[0084] I. Construction Process

[0085] Taking a 2.0m diameter borehole as an example, this paper introduces the usage method of a rotary drilling rig with a guide roller cutter for hard rock. During the construction of the pile hole, a 2.0m diameter rotary drilling bucket is used to drill into the soil layer until the bearing stratum rock surface. In the rock layer, two-stage drilling is used at 1.5m and 2.0m diameters.

[0086] 1. First 1.5m borehole: Drill to the design elevation of the pile bottom using a 1.5m diameter rotary drilling rig.

[0087] 2. Second stage 2.0m drilling: First, use a 1.5m diameter lower guide tube and a 2.0m diameter reamer (hard rock rotary drilling guide roller reamer with cutter head and flow chamber) to ream the hole to the design elevation of the pile bottom. Finally, use a 2.0m diameter rotary drilling rig to level the bottom of the hole.

[0088] II. Key Points of Construction Operation

[0089] 1) Pre-construction preparation

[0090] a: Remove all obstacles within the construction area, level the site, and replace and compact loose soil areas to ensure the safe movement of heavy equipment such as drilling rigs and crawler cranes in the construction area.

[0091] b: Based on the design drawings, use a total station to measure and lay out the pile positions, drive in the positioning piles, and install the casing.

[0092] c: Select the appropriate rotary drilling rig model based on the pile diameter, rock embedment depth and strength, and use the cross-shaped method to center the hole position.

[0093] 2) A 2.0m diameter rotary drilling bucket drills through the soil to the rock surface.

[0094] a: Use a 2.0m diameter rotary drilling bucket to drill through the soil layer until the strongly weathered bottom and the moderately weathered rock surface.

[0095] b: High-quality mud is used for wall protection during the drilling process in the soil layer.

[0096] c: After drilling to the bearing layer rock surface, promptly use a slag-removing flat-bottom drill bucket to repeatedly remove slag and soil.

[0097] 3) 1.5m diameter rotary drilling rig for primary drilling in rock formations

[0098] a: The first-stage drilling is carried out using a 1.5m diameter rotary drilling rig. After drilling to a certain depth, a core drill is used to extract the core. The drilling and core extraction process is repeated until the design elevation of the pile bottom is reached.

[0099] b: Finally, the bottom of the hole was leveled using a slag-removing drill bucket to complete the construction of the 1.5m diameter primary pilot hole.

[0100] 4) Hard rock rotary drilling with guide roller cutter and guide roller for second-stage reaming in rock formations using a 1.5m diameter lower guide tube and a 2.0m diameter reaming tube.

[0101] a: Use a 1.5m diameter lower guide tube and a 2.0m diameter reaming tube drill (hard rock rotary drilling guide tube drill with roller cutter and guide cavity) for reaming drilling in rock formations.

[0102] b: During the drilling process, the reaming barrel drill rotates to grind and break the second-stage annular cross-section. As the barrel drill rotates, it drives the mud to rotate and enter the guide cavity. The mud accelerates and rushes out from the roller drill bit, carrying away the drill cuttings produced by the breakage.

[0103] c: During the drilling process, after drilling a certain distance, a slag-removing drill bucket is used to remove slag in a timely manner.

[0104] d: Repeat the hole enlargement and slag removal process until the designed elevation of the pile bottom is reached.

[0105] 5) Level the bottom of the hole using a 2.0m diameter rotary drilling rig.

[0106] a: Due to the shape of the drill bit of the lower guide tube drill, the bottom of the hole is eventually stepped. A 2.0m diameter rotary drilling rig is used to level the bottom of the hole.

[0107] b: The drill cuttings generated at the bottom of the hole are cleaned using a cuttings removal drill bucket.

[0108] III. Scope of Application

[0109] It is suitable for large-diameter rotary drilling and staged enlargement drilling in hard rock, especially in rock formations where the rock cuttings after rotary crushing are small in size and are prone to "drill blockage".

[0110] IV. Features of the Device

[0111] 1) Strong rock-breaking ability: Compared with the roller cones and cutting teeth used in conventional tubular drills, this invention uses a roller cutter as the drill teeth, which has a stronger rock-breaking ability and can be used for reaming drilling in ultra-high strength rock masses.

[0112] 2) High drilling efficiency: This invention adds a flow guide device to the top of the drill bit to accelerate the mud flow, which can continuously and effectively flush the rotary drill bit and avoid the "drill bit jamming" phenomenon. The rotary drill bit is continuously in contact with the fresh rock surface due to the mud flushing, avoiding repeated crushing of rock cuttings, resulting in high overall drilling efficiency.

[0113] 3) Convenient transportation and installation: Compared with the conventional welded bottom guide reamer drill of the prior art, which has a large overall weight and volume, the bottom guide tube of the present invention is detachable, which is more convenient in terms of transportation, storage and installation.

[0114] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A drilling method for hard rock rotary drilling with guide roller cutter and under-guided reaming barrel, characterized in that, The construction steps include the following: 1) The drill rod is connected to the rotary drilling bucket, which is used to drill in the soil until the surface of the rock layer is reached, forming a hole in the soil layer; 2) Remove the rotary drilling bucket and connect the drill rod to the rotary drilling rig. The rotary drilling rig drills into the rock strata to form a guide hole located below the soil hole. The diameter of the guide hole is smaller than the diameter of the soil hole. 3) Remove the rotary drilling rig and connect the reamer and the lower guide cylinder to the drill rod. The diameter of the reamer is the same as the diameter of the soil hole, and the diameter of the lower guide cylinder is the same as the diameter of the guide hole. The lower guide cylinder is located below the reamer. The bottom of the reamer is provided with multiple roller drill bits, which are arranged at intervals around the reamer. The reaming barrel drill has a flow guiding cavity, the hobbing drill bit is arranged at the bottom of the flow guiding cavity, the flow guiding cavity penetrates the bottom of the reaming barrel to form a flow guiding inlet, and the flow guiding cavity penetrates the top of the reaming barrel to form a flow guiding outlet; The reaming drill barrel reams the guide hole in the rock strata, and the lower guide cylinder moves synchronously along the guide hole until the lower guide cylinder moves to the bottom of the guide hole, and the guide hole has an unreamed section that has not been drilled. During the process of the borehole enlargement drill in the rock strata, the mud enters the guide cavity through the guide inlet and is then sprayed upward from the guide outlet. 4) Remove the lower guide cylinder and use the unexpanded section of the reaming cylinder to drill the reaming hole until the bottom of the guide hole is reached. The guide hole is expanded to form a rock layer hole. The diameter of the rock layer hole is the same as that of the soil layer hole. The soil layer hole and the rock layer hole are connected vertically to form a pile hole.

2. The drilling method for hard rock rotary drilling with guide roller cutter and under-guided reaming barrel as described in claim 1, characterized in that, In construction step 1), before the rotary drilling bucket drills into the soil layer, the construction site is compacted and leveled, and a casing is installed in the soil layer; the rotary drilling bucket drills into the casing to form the soil layer hole.

3. The drilling method for hard rock rotary drilling with guide roller cutter and under-guided reaming barrel as described in claim 1, characterized in that, In construction step 3), during the process of drilling the guide hole using the reamer, the slag in the guide hole is scooped out using the slag-removing drill bucket until the lower guide cylinder moves to the bottom of the guide hole.

4. The hard rock rotary drilling method with guide roller cutter and under-guided reaming barrel drilling as described in any one of claims 1-3, characterized in that, In construction step 3), the bottom of the reaming barrel drill is provided with multiple cutter sets, which are arranged at intervals around the circumference of the reaming barrel drill; each cutter set includes multiple cutter bits, and the diameter distance between the multiple cutter bits of the cutter set and the center of the reaming barrel drill is different.

5. The drilling method for hard rock rotary drilling with guide roller cutter and under-guided reaming barrel as described in claim 4, characterized in that, In construction step 3), along the arrangement direction of the multiple roller drill bits of the roller cutter group, the diameter distance between the center of the multiple roller drill cylinders of the roller cutter group and the center of the reaming cylinder gradually decreases or increases.

6. The drilling method for hard rock rotary drilling with guide roller cutter and under-guided reaming barrel as described in any one of claims 1-3, characterized in that, In construction step 3), the reaming cylinder surrounds an inner cavity, and an upper connecting cylinder is provided in the inner cavity; the top of the lower guide cylinder is provided with a lower connecting cylinder that is detachably connected to the upper connecting cylinder. The upper connecting cylinder is inserted into the lower connecting cylinder and is connected to the lower connecting cylinder as a whole. The lower guide cylinder is located below the reaming cylinder drill.

7. The drilling method for hard rock rotary drilling with guide roller cutter and under-guided reaming barrel as described in claim 6, characterized in that, In construction step 3), the upper connecting cylinder is provided with multiple upper through holes, which are arranged around the upper connecting cylinder at intervals in the circumference. The lower connecting cylinder is provided with multiple lower through holes, which are arranged around the lower connecting cylinder at intervals in the circumference. The upper connecting cylinder is provided with a positioning block protruding from its outer periphery, and the lower connecting cylinder is provided with a positioning groove with a top opening. When the upper connecting cylinder is inserted into the lower connecting cylinder, the positioning block is embedded in the positioning groove through the top opening. The multiple upper through holes are respectively aligned with the multiple lower through holes. Bolts are inserted into the lower through holes, and the bolts pass through the upper through holes simultaneously, fixing the upper connecting cylinder and the lower connecting cylinder relative to each other.

8. The drilling method for hard rock rotary drilling with guide roller cutter and under-guided reaming barrel as described in any one of claims 1-3, characterized in that, In construction step 3), the reaming cylinder includes an inner cylinder and an outer cylinder surrounding the outer periphery of the inner cylinder. The inner cylinder encloses and forms the inner cavity, and the outer cylinder and the inner cylinder form the flow guide cavity. The bottom of the flow guiding cavity is covered by an annular bottom plate, and multiple rotary drill bits are disposed on the bottom plate, with multiple flow guiding inlets formed on the bottom plate; the top of the reaming tube drill is provided with a top plate, which covers the top of the inner cavity and the top of the flow guiding cavity, with multiple flow guiding outlets formed on the top plate, and multiple pressure relief holes provided in the top plate, with the multiple pressure relief holes communicating with the top of the inner cavity.

9. The drilling method for hard rock rotary drilling with guide roller cutter and under-guided reaming barrel as described in claim 8, characterized in that, In construction step 3), the flow guiding cavity is provided with multiple flow guiding cylinders. The flow guiding cylinders extend along the axial direction of the reaming cylinder. The bottom of the flow guiding cylinder abuts against the bottom plate and communicates with the flow guiding inlet. The top of the flow guiding cylinder abuts against the top plate and communicates with the flow guiding outlet. The top plate is provided with multiple guide covers, and the multiple guide covers are respectively provided with multiple flow outlets; the guide covers enclose to form a lateral cavity, the bottom of the lateral cavity is connected to the flow outlet, the lateral cavity forms a lateral opening, and the lateral opening is arranged opposite to the rotation direction of the reaming drill; along the direction from the flow outlet to the lateral opening, the height of the lateral cavity gradually increases; In construction steps 3 and 4), during the process of the reaming drill in the guide hole, the mud enters the guide tube through the guide inlet and is then discharged into the lateral cavity through the guide outlet. The mud is blocked by the top of the guide cover and sprayed out toward the lateral opening.

10. The drilling method for hard rock rotary drilling with guide roller cutter and under-guided reaming barrel as described in claim 8, characterized in that, In construction step 3), the top plate has a bottom surface located at the bottom of the lateral cavity, and the bottom surface is arranged inclined downward along the direction from the guide outlet to the lateral opening; Multiple elastic strips are formed on the bottom surface. Along the direction from the flow outlet to the lateral opening, the multiple elastic strips are arranged sequentially at intervals, and the elastic strips are arranged to extend laterally along the lateral cavity. Along the direction from bottom to top, the elastic strips are arranged inclined toward the lateral opening, and there is an elastic interval between adjacent elastic strips. In construction steps 3 and 4), during the process of the reaming drill in the guide hole, the mud discharged from the guide outlet flows toward the lateral opening, and the multiple elastic strips are pressed and swing back and forth, and the multiple elastic strips restrict the mud from flowing in the opposite direction toward the guide outlet.

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