Horizontal drilling rotary jet grouting pile forming device and construction method thereof

Abstract

The present application relates to the field of geotechnical engineering construction, disclose a kind of horizontal drilling rotary jet grouting pile-forming device, including walking mechanism, azimuth angle adjusting mechanism, height elevation angle adjusting mechanism and rotary jet grouting mechanism, rotary jet grouting mechanism includes slide, front power head, wall protection sleeve, rear power head, drill pipe and drill head, front power head and rear power head are slidably connected on slide, front power head is detachably connected with wall protection sleeve, front power head is used to drive wall protection sleeve to move along front-back direction, rear power head is detachably connected with one end of drill pipe, rear power head is used to drive drill pipe to rotate and move along front-back direction, drill pipe and wall protection sleeve are coaxial, the other end of drill pipe is detachably connected with drilling drill head or grouting drill head, furthermore the present application also discloses a kind of construction method based on above-mentioned device.The present application can effectively prevent borehole collapse, reduce the amount of abandoned slurry in construction process, the present application is stable, and pile diameter meets design requirements.

Description

Technical Field

[0001] This invention relates to the field of geotechnical engineering construction, and in particular to a horizontal drilling rotary jet grouting pile-forming device and its construction method. Background Technology

[0002] In underground tunneling projects, adverse geological conditions such as mudslides, water inrushes, sand inrushes, silt, and fractured rock strata are often encountered. These adverse geological conditions bring great difficulties to tunneling construction and pose huge safety hazards to safe production.

[0003] When conducting underground tunneling under adverse geological conditions, methods such as advanced small-diameter pipes, pipe roof support, or advanced consolidation grouting are generally employed. However, these methods have certain limitations in some areas with poor geological conditions, and cannot guarantee safe tunneling. For example, when using pipe roof support for silty sand layers, due to the gaps between the steel pipes, advanced small-diameter pipes are often used to supplement the consolidation with cement grout. However, because the rock mass in this type of geological formation is relatively dense, the cement grout is difficult to penetrate and diffuse evenly. Therefore, even if pipe roof support provides some support to the soil and rock, the possibility of collapse still exists. Especially in water-bearing fine sand layers, if advanced consolidation grouting or advanced curtain grouting is used directly, it is difficult for the grout to diffuse using pure pressure grouting methods due to the relatively dense surrounding rock. Even if some diffusion occurs, the cement grout will exist in the form of grout veins or grout pockets, with insignificant support effect on the soil, easily leading to collapse.

[0004] Practice has proven that using horizontal jet grouting piles to replace advanced small guide pipes, pipe roof support, or advanced consolidation grouting methods can significantly compensate for the shortcomings of these techniques during tunneling in adverse geological conditions. The existing construction process for horizontal jet grouting piles generally involves: pre-drilling holes at the designed depth and angle; after drilling, removing the drill rod; then replacing it with a jet grouting drill rod for the jet grouting process; or using a pilot drilling rig, which makes way for the jet grouting rig after drilling its own hole. When the jet grouting drill rod extends to the bottom of the hole, a hole-sealing device is installed at part of the drill rod end. This device reduces the amount of grout returned and facilitates the centralized collection and treatment of waste grout. However, this process still has the following drawbacks: Because the areas treated are all in poor geological conditions, the borehole is prone to collapse after drilling. Even after the drill rod is removed from the hole and replaced with a jet grouting drill rod, the borehole will still collapse, and gravel will fill the gap between the drill rod and the borehole wall, reducing the mixing space between the cement grout and the gravel. This creates a high-pressure state inside the borehole, at which point the cement grout will backflow to the borehole opening to release pressure. If there is no pressure relief outlet, this can lead to problems such as grout pipe bursting, grouting machine overload shutdown, or soil and rock deformation. Due to the small mixing space of the cement grout inside the borehole, the final pile formation effect is poor, generally manifested as a small pile diameter, uneven mixing of cement grout, and excessive grout waste. Summary of the Invention

[0005] To overcome the shortcomings mentioned above, this invention aims to provide a horizontal drilling rotary jet grouting pile forming device and its construction method.

[0006] To achieve the above objectives, the present invention provides a horizontal drilling rotary jet grouting pile-forming device, comprising:

[0007] The traveling mechanism is used to adjust the position of the jet grouting mechanism;

[0008] An azimuth adjustment mechanism is used to adjust the azimuth angle of the jet grouting mechanism;

[0009] A height and elevation adjustment mechanism is used to adjust the height and elevation angle of the jet grouting mechanism;

[0010] The rotary jet grouting mechanism includes a slide, a front power head, a wall-protecting sleeve, a rear power head, a drill rod, and a drill bit. The front power head and the rear power head are slidably connected to the slide. The front power head is detachably connected to the wall-protecting sleeve and is used to drive the wall-protecting sleeve to move in the front-back direction. One end of the drill rod is detachably connected to the rear power head and is used to drive the drill rod to rotate and move in the front-back direction. The drill rod and the wall-protecting sleeve are coaxially arranged, and the outer diameter of the drill rod is smaller than the inner diameter of the wall-protecting sleeve. The other end of the drill rod is detachably connected to a drill bit, which includes a drilling drill bit and a grouting drill bit.

[0011] Furthermore, the drilling bit includes an impactor and an impact drill bit. During drilling, the other end of the drill rod, the impactor, and the impact drill bit are detachably connected in sequence, and the impactor is installed through the protective sleeve.

[0012] During grouting, the other end of the drill rod is detachably connected to the grouting drill bit, which is installed through the protective sleeve.

[0013] Furthermore, the drill rod is provided with an air injection channel and a grouting channel. During drilling, the air injection channel is selectively connected to the impactor, and during grouting, the air injection channel and the grouting channel are selectively connected to the grouting drill bit.

[0014] Furthermore, the grouting drill bit includes:

[0015] The air intake channel is selectively connected to the air injection channel;

[0016] An air outlet is provided along the radial direction of the grouting drill bit and is connected to the air inlet channel;

[0017] The grout inlet channel is selectively connected to the grouting channel;

[0018] The grout outlet is provided along the radial direction of the grouting drill bit and is connected to the grout inlet channel.

[0019] Furthermore, the rotary jet grouting mechanism also includes a pipe shoe, which is a hollow annular structure with a stepped outer wall. The small-diameter end of the pipe shoe is detachably connected to the end of the protective sleeve away from the front power head. The inner wall diameter of the pipe shoe is smaller than the outer wall diameter of the drill pipe, and the inner wall diameter of the pipe shoe is greater than or equal to the outer wall diameter of the impactor.

[0020] The outer wall of the grouting drill bit is provided with an annular protrusion. The inner diameter of the annular protrusion is less than or equal to the inner diameter of the protective sleeve, and the outer diameter of the annular protrusion is greater than the inner diameter of the pipe shoe.

[0021] Furthermore, the walking mechanism is a tracked walking mechanism;

[0022] The azimuth adjustment mechanism includes a bracket, a support frame, a first power telescopic component, a rotating rod, a first gear, and a first rack. The bracket is fixedly installed above the track walking mechanism. The support frame is fixedly installed on the upper surface of the bracket. The support frame is inverted "Ω" shape. The rotating rod is rotatably connected inside the support frame. The first gear is coaxially fixedly connected to the outer wall of the rotating rod. The fixed end of the first power telescopic component is fixedly connected to the upper surface of the bracket. The movable end of the first power telescopic component is fixedly connected to the first rack. The first rack is slidably connected to the upper surface of the bracket, and the first rack meshes with the first gear.

[0023] The elevation adjustment mechanism includes a second power telescopic member and a third power telescopic member. The lower end of the second power telescopic member is hinged to the rear end side wall of the rotating rod, and the upper end of the second power telescopic member is hinged to the front end of the carriage. The lower end of the third power telescopic member is hinged to the front end side wall of the rotating rod, and the upper end of the third power telescopic member is hinged to the rear end of the carriage.

[0024] Furthermore, the front power head and the rear power head are detachably connected by fasteners.

[0025] Compared with the prior art, the present invention has at least the following advantages:

[0026] The horizontal drilling rotary jet grouting pile forming device of this invention, due to the installation of a protective sleeve, avoids borehole collapse when the drill rod and drill bit are withdrawn from the borehole; because the grouting drill bit passes through the protective sleeve, it avoids the situation of the grouting drill bit passing through a collapsed borehole, and the grouting drill bit will not get stuck or jammed, thus improving the service life of the grouting drill bit; during construction, there is no need to disassemble and assemble the drill rod, only the drill bit needs to be replaced, which can quickly improve the construction speed; the installation of the protective sleeve also reduces the phenomenon of grout wastage caused by grout pressure leakage from the borehole opening in traditional construction processes, reducing the amount of grout wasted during construction and reducing construction material costs; the pile quality formed by the horizontal drilling rotary jet grouting pile forming device of this invention is stable, and the pile diameter meets the design requirements.

[0027] Another aspect of the present invention provides a construction method based on the above-mentioned horizontal drilling rotary jet grouting pile forming device, comprising the following steps:

[0028] S1. Lay out the lines and mark the drilling points;

[0029] S2. Installation of the protective sleeve and drill pipe: Install the protective sleeve on the front power head and install the drill pipe on the rear power head;

[0030] S3. Positioning: Control the walking mechanism to adjust the position of the jet grouting mechanism; control the azimuth adjustment mechanism to adjust the azimuth angle of the jet grouting mechanism; control the height and elevation adjustment mechanism to adjust the height and elevation angle of the jet grouting mechanism.

[0031] S4. Install the drilling bit, install the drilling bit on the other end of the drill rod, and slide the front power head and the rear power head to the rear end of the slide, so that the drill rod is sleeved in the protective sleeve, and the drilling bit is set through the protective sleeve, so that the drill rod is set towards the drilling point.

[0032] S5. Drilling: Control the front power head and the rear power head to move simultaneously toward the front end of the slide. The drilling bit drives the protective sleeve to drill a hole in the structural layer. Drilling stops after reaching the designed hole depth.

[0033] S6. Replace the grouting drill bit, control the rear power head to slide to the rear end of the slide, replace the drill bit with a grouting drill bit, and control the rear power head to slide to the front end of the slide so that the grouting drill bit penetrates the protective sleeve.

[0034] S7. Spraying and retraction: Air and grout are injected into the borehole through the drill rod and grouting drill bit, and the front power head and rear power head are controlled to make the wall casing and grouting drill bit withdraw from the borehole.

[0035] S8. Seal the borehole opening;

[0036] Repeat steps S3 to S8 until construction is complete.

[0037] Furthermore, step S5 also includes introducing air into the drill bit through the drill rod;

[0038] In step S7, the front power head and the rear power head retract intermittently to withdraw the wall casing and the grouting drill bit from the borehole.

[0039] Furthermore, in steps S5 and S7, the front power head and the rear power head are connected by fasteners; in the remaining steps, the front power head and the rear power head are not connected.

[0040] The horizontal drilling rotary jet grouting pile construction method described above has the same advantages as the aforementioned horizontal drilling rotary jet grouting pile construction device compared to existing technologies, and will not be repeated here. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0042] Figure 1 This is a three-dimensional structural schematic diagram of the horizontal drilling rotary jet grouting pile forming device of the present invention (when using a drilling bit);

[0043] Figure 2 This is a cross-sectional schematic diagram of the horizontal drilling rotary jet grouting pile forming device of the present invention (when using a drilling bit);

[0044] Figure 3 This is a schematic diagram of the structure of the drilling bit, drill rod and casing of the present invention when used together.

[0045] Figure 4 For the present invention Figure 3 Sectional view along line AA;

[0046] Figure 5 For the present invention Figure 4 A magnified view of a portion of region B in the middle;

[0047] Figure 6 This is a three-dimensional structural schematic diagram of the horizontal drilling rotary jet grouting pile forming device of the present invention (when using a grouting drill bit);

[0048] Figure 7 This is a schematic diagram of the structure of the grouting drill bit, drill rod, and casing of the present invention when used together.

[0049] Figure 8 For the present invention Figure 7 A cross-sectional view along the CC line;

[0050] Figure 9 For the present invention Figure 8 A magnified view of a portion of region D in the middle;

[0051] Figure 10 This is a flowchart of the construction method for the horizontal drilling rotary jet grouting pile forming device of the present invention.

[0052] Reference numerals: 1. Slide; 2. Front power head; 3. Casing; 4. Rear power head; 5. Drill rod; 6. Drill bit; 7. Grouting bit; 8. Shoe; 9. Tracked walking mechanism; 10. Support; 11. Support frame; 12. First power telescopic component; 13. Rotating rod; 14. First gear; 15. First rack; 16. Support square tube; 17. Reinforcing member; 18. Second power telescopic component; 19. Third power telescopic component; 101 102. Slide rail; 103. Second rack; 104. Third rack; 205. First drive motor; 206. Second gear; 207. Second drive motor; 408. Third drive motor; 409. Third gear; 500. Air injection channel; 500. Grouting channel; 601. Impactor; 602. Impact drill bit; 603. Converter joint; 701. Air inlet channel; 702. Air outlet; 703. Grouting channel; 704. Grouting outlet. Detailed Implementation

[0053] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0054] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0055] Reference Figure 1 and Figure 6 The present invention provides a horizontal drilling rotary jet grouting pile forming device, including a traveling mechanism, an azimuth angle adjustment mechanism, an elevation angle adjustment mechanism, and a rotary jet grouting mechanism.

[0056] Herein, in the present invention, the traveling mechanism adopts a crawler traveling mechanism 9, which serves as the moving mechanism of the rotary jet grouting pile forming device of the present invention, and can drive the rotary jet grouting mechanism to move position. The crawler has a large ground contact area, which can reduce the pressure on the ground, and facilitates traveling on soft, muddy or uneven ground.

[0057] With reference to Figure 2 , the azimuth angle adjusting mechanism is used for adjusting the azimuth angle of the rotary jet grouting mechanism. Specifically, the azimuth angle adjusting mechanism comprises a bracket 10, a bearing bracket 11, a first power telescopic member 12, a rotating rod 13, a first gear 14 and a first rack 15. The bracket 10 is fixedly connected with the upper surface of the traveling mechanism 9. The bearing bracket 11 is fixedly arranged on the upper surface of the bracket 10, the bearing bracket 11 is in an inverted "Ω" shape, a reinforcing member 17 is arranged between the middle part of the bearing bracket 11 and the bracket 10, the reinforcing member 17 is in an inverted "几" shape, the middle bottom of the reinforcing member 17 is fixedly connected with the bracket 10, supporting square tubes 16 are arranged between the two ends of the reinforcing member 17 and the bracket 10, the side wall of the bottommost part of each supporting square tube 16 is fixedly connected with the bracket 10, the side wall of the topmost part of each supporting square tube 16 is connected with the reinforcing member 17, the upper surface of the reinforcing member 17 is attached to the lower surface of the bearing bracket 11, and the arrangement of the supporting square tubes 16 and the reinforcing member 17 can ensure the stability of the bearing bracket 11. The middle part of the bearing bracket 11 is arc-shaped and is in the form of a major arc, that is, the arc at the middle part of the bearing bracket 11 is an arc whose corresponding central angle is greater than 180°. The middle part of the bearing bracket 11 is rotatably connected with the rotating rod 13, and the outer side wall of the rotating rod 13 is coaxially and fixedly connected with the first gear 14. The upper surface of the bracket 10 is fixedly connected with the fixed end of the first power telescopic member 12, the movable end of the first power telescopic member 12 is fixedly connected with the first rack 15, the first rack 15 is slidably connected with the upper surface of the bracket 10, the first rack 15 and the rotating rod 13 are arranged perpendicular to each other, and the first rack 15 is engaged with the first gear 14. A height elevation angle adjusting mechanism and a rotary jet grouting mechanism are arranged above the rotating rod 13. In use, the movable end of the first power telescopic member 12 extends and retracts to drive the first rack 15 to move, so as to drive the first gear 14 to rotate, realizing the autorotation process of the rotating rod 13, and the rotation of the rotating rod 13 drives the height elevation angle adjusting mechanism and the rotary jet grouting mechanism to rotate, so as to realize the adjustment of the azimuth angle of the rotary jet grouting mechanism.

[0058] Optionally, two bearing brackets 11 are arranged along the axial direction of the rotating rod 13, a limit protrusion is arranged on the circumferential direction of the rotating rod 13, the limit protrusion is in a circular ring shape, a limit groove is arranged on the bearing bracket 11, and the limit groove is slidably connected with the limit protrusion. The arrangement of the limit groove and the limit protrusion can limit the displacement of the rotating rod 13 along its axial direction, and prevent the rotating rod 13 from slipping out of the bearing bracket 11.

[0059] The elevation angle adjustment mechanism adopts a telescopic scissor mechanism. Specifically, the elevation angle adjustment mechanism includes a second power telescopic component 18 and a third power telescopic component 19, which together form a scissor mechanism. The jet grouting mechanism includes a carriage 1, with a rotary jet grouting assembly mounted above the carriage 1. The lower end of the second power telescopic component 18 is hinged to the rear end side wall of the rotating rod 13, and the upper end of the second power telescopic component 18 is hinged to the front end of the carriage 1. The lower end of the third power telescopic component 19 is hinged to the front end side wall of the rotating rod 13, and the upper end of the third power telescopic component 19 is hinged to the rear end of the carriage 1. When the second power telescopic component 18 and the third power telescopic component 19 are of equal length, the carriage 1 is in a horizontal state; when the length of the second power telescopic component 18 is less than the length of the third power telescopic component 19, the carriage 1 is in an inclined state, suitable for drilling with an elevation angle. Generally, the drilling angle is 2 to 5 degrees or as required by the design.

[0060] In this embodiment of the invention, two second power telescopic members 18 are provided, and the two second power telescopic members 18 are arranged in parallel. The two second power telescopic members 18 can simultaneously realize the telescopic function to ensure the stability of the carriage 1.

[0061] It should be noted that the first power telescopic component 12, the second power telescopic component 18, and the third power telescopic component 19 are components that can control telescopic movement, such as electric push rods, pneumatic push rods, or hydraulic push rods.

[0062] The jet grouting mechanism also includes a front power head 2, a wall-protecting sleeve 3, a rear power head 4, a drill rod 5, and a drill bit. The lower surface of the slide 1 is hinged to the upper ends of the second power telescopic member 18 and the third power telescopic member 19, respectively, and the front power head 2 and the rear power head 4 are slidably connected to the upper surface of the slide 1. Preferably, the upper surface of the slide 1 is provided with a slide rail 101 arranged in the front-to-back direction, and the lower surfaces of the front power head 2 and the rear power head 4 are provided with sliding grooves that are adapted to the slide rail 101. The front power head 2 and the rear power head 4 are connected to the slide rail 101 by means of the sliding grooves. Specifically, a second rack 102 is fixedly connected to the upper surface of the slide 1. The second rack 102 is arranged parallel to the slide rail 101. The front power head 2 is used to drive the protective sleeve 3 to move in the front-back direction. The front power head 2 includes a first support frame, a first drive motor 201, and a second drive motor 203. The first support frame is a hollow structure, which is arranged in the front-back direction. The first drive motor 201 is fixedly connected to the first support frame. The output shaft of the first drive motor 201 is driven by a second gear 202. The second gear 202 meshes with the second rack 102. The first drive motor 201 drives the second gear 202 to rotate, which can drive the first support frame to move in the front-back direction of the slide 1. The first support frame is fixedly connected to the second drive motor 203. The output shaft of the second drive motor 203 is arranged through the hollow structure. The output shaft of the second drive motor 203 is detachably connected to the protective sleeve 3. Optionally, the output shaft of the second drive motor 203 has an external thread at the end near the protective sleeve 3, and the protective sleeve 3 has an internal thread at the end near the second drive motor 203. The output shaft of the second drive motor 203 and the end of the protective sleeve 3 near the second drive motor 203 are threaded together, and the forward and reverse rotation of the output shaft of the second drive motor 203 enables a quick assembly and disassembly process with the protective sleeve 3. The outer diameter of the protective sleeve 3 is adjusted according to the pile size, typically 150mm-220mm. The protective sleeve 3 is used to prevent borehole collapse and to provide sufficient space for subsequent cement slurry injection. A third rack 103 is also fixedly connected to the upper surface of the slide 1, and the third rack 103 is arranged parallel to the slide rail 101. The rear power head 4 is detachably connected to one end of the drill rod 5. The rear power head 4 is used to drive the drill rod 5 to rotate and move in the forward and backward direction. The drill rod 5 is coaxially arranged with the protective sleeve 3. The rear power head 4 includes a second support frame, a third drive motor 401, and a fourth drive motor (not shown in the figure). The side wall of the second support frame is fixedly connected to the third drive motor 401. The output shaft of the third drive motor 401 is connected to a third gear 402. The third gear 402 meshes with the third rack 103. The third drive motor 401 drives the third gear 402 to rotate, which can drive the second support frame to move along the front and rear direction of the slide 1. The second support frame is fixedly connected to the fourth drive motor. The output shaft of the fourth drive motor is detachably connected to the drill rod 5.The third drive motor 401 is used to drive the drill rod 5 to move in the front-to-back direction, and the fourth drive motor is used to drive the drill rod 5 to achieve the rotation process. In this invention, the outer diameter of the drill rod 5 is smaller than the inner diameter of the casing 3, and the other end of the drill rod 5 is detachably connected to a drill bit, which includes a drilling drill bit 6 and a grouting drill bit 7.

[0063] In this invention, the sliding length of the front and rear power heads on the slide is greater than the depth of the designed hole, eliminating the need to disassemble or assemble the drill rod during construction. Conventional drilling operations require approximately 60 minutes to disassemble and assemble a drill rod for a 30m hole, but this device only requires replacing the drill bit, significantly improving construction efficiency.

[0064] The drilling bit 6 includes an impactor 601 and an impact drill bit 602. During drilling, the other end of the drill rod 5, the impactor 601 and the impact drill bit 602 are detachably connected in sequence. The impactor 601 is installed through the protective sleeve 3. The impactor 601 is a pneumatic impactor, which can be powered by inputting high-pressure air. The impactor 601 is directly connected to the impact drill bit 602 to drill into the soft soil layer by impact. The drilling is carried out by low-speed rotation without coring.

[0065] During rotary jet grouting for pile formation, the other end of the drill rod 5 is detachably connected to a grouting drill bit 7, which extends through the protective casing 3. During grouting, grout and air are ejected from the grouting drill bit 7, and the drill rod 5 and the protective casing are withdrawn from the borehole in an intermittent retraction manner.

[0066] During drilling, the other end of drill rod 5 is connected to drill bit 6. Drill rod 5 and casing 3 are drilled into the borehole simultaneously. After reaching the designed depth, drill rod 5 is withdrawn from casing 3, ensuring that casing 3 remains inside the borehole. Drill bit 6 at the other end of drill rod 5 is replaced with grouting bit 7. Drill rod 5 is then re-inserted into casing 3, ensuring that the tip of grouting bit 7 penetrates casing 3. During grouting, drill rod 5 and casing 3 are withdrawn from the borehole intermittently, while high-pressure air and grout are injected into the soil through drill rod 5 and grouting bit 7. For the grout, a pressure of 40 MPa or higher is recommended. Cement grout or a two-component cement grout should be used. When the casing 3 connects to the drill rod 5 and retracts, a temporary cavity will form within the bedrock. The grout will then be injected into the soil and mixed with the collapsed soil above. During the collapse, the upper soil and rock will gradually loosen, facilitating grout injection. After the grout fills the borehole cavity, it will mix with the upper bedrock to achieve density, generating high pressure. This high pressure will push the casing 3 backward (i.e., the casing 3 moves backward) and create another cavity. This cycle continues until the pile is formed and then sealed. The mixing depth of the lower soil and rock will be much shallower than the upper layer, saving considerable material, as the area within the excavation outline already needs to be cleared.

[0067] The horizontal drilling rotary jet grouting pile forming device of this invention, due to the installation of the protective sleeve 3, avoids borehole collapse when the drill rod 5 and drilling bit 6 are withdrawn from the borehole; since the grouting drill bit 7 passes through the protective sleeve 3, it avoids the situation of the grouting drill bit 7 passing through the collapsed borehole, and the grouting drill bit 7 will not get stuck or jammed, thus improving the service life of the grouting drill bit 7; during construction, there is no need to disassemble and assemble the drill rod 5, only the drill bit needs to be replaced, which can quickly improve the construction speed; due to the installation of the protective sleeve 3, the phenomenon of grout wastage caused by grout pressure leakage from the borehole opening in traditional construction processes can be reduced, reducing the amount of grout wasted during construction and reducing construction material costs; the horizontal drilling rotary jet grouting pile forming device of this invention is suitable for the treatment of poor terrain such as silt, clay or gravel encountered in underground tunneling projects, and has the advantages of stable pile quality and pile diameter meeting design requirements.

[0068] Preferably, refer to Figures 3 to 5 as well as Figures 7 to 9 In this invention, the drill rod 5 is provided with an air injection channel 501 and a grouting channel 502, both of which are parallel to the axis of the drill rod 5. The air injection channel 501 and the grouting channel 502 are used to transport high-pressure air and grout, respectively. When the other end of the drill rod 5 is connected to the impactor 601, the air injection channel 501 is connected to the impactor 601, and high-pressure air is supplied to the impactor 601 through the air injection channel 501 to provide power to the impactor 601. When the other end of the drill rod 5 is connected to the grouting drill bit 7, the high-pressure air is supplied to the grouting drill bit 7 through the air injection channel 501, and the grout is supplied to the grouting drill bit 7 through the grouting channel 502 to realize the rotary jet grouting process.

[0069] Optionally, the grouting drill bit 7 is provided with an air outlet 702 and a grout outlet 704 arranged radially. In addition, the grouting drill bit 7 is also provided with an air inlet channel 701 and a grout inlet channel 703, which are respectively connected to the air outlet 702 and the grout outlet 704. During grouting, the other end of the drill rod 5 is connected to the grouting drill bit 7. At this time, the air inlet channel 701 is connected to the air injection channel 501, and the grout inlet channel 703 is connected to the grout injection channel 502.

[0070] Preferably, the rotary jet grouting mechanism further includes a pipe shoe 8, which is a hollow annular structure with a stepped outer wall. The small-diameter end of the pipe shoe 8 has an external thread, and the end of the protective sleeve 3 furthest from the front power head 2 has an internal thread. The small-diameter end of the pipe shoe 8 and the end of the protective sleeve 3 furthest from the front power head 2 are connected by threads for disassembly. The inner diameter of the pipe shoe 8 is smaller than the outer diameter of the drill rod 5. After assembling the pipe shoe 8, the inner wall of the pipe shoe 8 and the inner wall of the protective sleeve 3 form a stepped structure. During drilling, the pipe shoe 8 provides a force point for the drill rod 5, allowing the drill rod 5 to provide jacking power to the protective sleeve 3 based on this force point. The inner diameter of the pipe shoe 8 is greater than or equal to the outer diameter of the impactor 601, and the impactor 601 can penetrate the pipe shoe 8. If necessary, the impactor 601 can be connected to the other end of the protective sleeve 3 via a conversion connector 603.

[0071] The outer wall of the grouting drill bit 7 has an annular protrusion. The inner diameter of the annular protrusion is less than or equal to the inner diameter of the protective sleeve 3, and the outer diameter of the annular protrusion is greater than the inner diameter of the pipe shoe 8. During grouting, the annular protrusion abuts against the pipe shoe 8 to form a sealing structure, which can prevent the grout from flowing back into the protective sleeve 3 during the grouting jet, thus improving the utilization efficiency of the grout.

[0072] In this design, the front power head 2 and the rear power head 4 are detachably connected by fasteners (not shown in the figure), which can be snap-fit ​​fasteners. Specifically, the first support frame and the second support frame are detachably connected by fasteners. During drilling and grouting, fixing the front power head 2 and the rear power head 4 together allows the drill rod 5 and the casing to move simultaneously.

[0073] Reference Figure 10 In another aspect, the present invention provides a construction method based on the above-mentioned horizontal drilling rotary jet grouting pile forming device. Specific steps include:

[0074] S1. Lay out the lines and mark the drilling points;

[0075] S2, Install the wall casing 3 and drill pipe 5, install the wall casing 3 and drill pipe 5, install the wall casing 3 on the front power head 2, and install the drill pipe 5 on the rear power head 4;

[0076] S3. Positioning: Control the traveling mechanism to adjust the position of the jet grouting mechanism; control the azimuth adjustment mechanism to adjust the azimuth angle of the jet grouting mechanism; control the height and elevation adjustment mechanism to adjust the height and elevation angle of the jet grouting mechanism.

[0077] S4. Install the drilling bit 6. Install the drilling bit 6 on the other end of the drill rod 5, and slide the front power head 2 and the rear power head 4 to the rear end of the slide frame 1 so that the drill rod 5 is fitted inside the protective sleeve 3, and the drilling bit 6 is set through the protective sleeve 3 so that the drill rod 5 is set towards the drilling point.

[0078] S5. Drilling: Control the front power head 2 and the rear power head 4 to move simultaneously towards the front end of the slide 1. The drilling bit 6 drives the protective sleeve 3 to drill a hole in the structural layer. The drilling stops after reaching the designed hole depth. High-pressure air is injected into the impactor 601 through the drill rod 5 to impact and crush the rock and soil. After the debris is discharged by the high-pressure air, the protective sleeve 3 is pushed in.

[0079] S6. Replace the grouting drill bit 7, control the rear power head 4 to slide to the rear end of the slide 1, replace the drill bit with the grouting drill bit 7, and control the rear power head 4 to slide to the front end of the slide 1 so that the grouting drill bit 7 penetrates the protective sleeve 3.

[0080] S7, rotary jetting and retraction, injecting high-pressure air and grout into the borehole through drill rod 5 and grouting drill bit 7, controlling the front power head 2 and rear power head 4 to make the wall casing 3 and grouting drill bit 7 withdraw from the borehole;

[0081] S8. Seal the borehole opening;

[0082] Repeat steps S3 to S8 until construction is complete.

[0083] The horizontal drilling rotary jet grouting pile construction method of the present invention has the same advantages as the aforementioned horizontal drilling rotary jet grouting pile construction device compared to the prior art, and will not be repeated here. Furthermore, using this construction method, there is no need to install a borehole sealing device, and the grout will not return to the borehole opening under reasonable advance and retreat speed control.

[0084] Furthermore, step S5 also includes introducing air into the drill bit 6 through the drill pipe 5;

[0085] In step S7, the front power head 2 and the rear power head 4 use an intermittent retraction method to withdraw the wall casing 3 and the grouting drill bit 7 from the borehole, with each retraction distance being 10cm.

[0086] Furthermore, in steps S5 and S7, the front power head 2 and the rear power head 4 are connected by fasteners; in the remaining steps, the front power head 2 and the rear power head 4 are not connected. During drilling and jet grouting, the front power head 2 and the rear power head 4 are connected by snap-fit ​​to achieve synchronous advance and retreat, improving the stability of the hole formation.

[0087] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0088] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A horizontal drilling rotary jet grouting pile forming device, characterized in that, include: The traveling mechanism is used to adjust the position of the jet grouting mechanism; An azimuth adjustment mechanism is used to adjust the azimuth angle of the jet grouting mechanism; A height and elevation adjustment mechanism is used to adjust the height and elevation angle of the jet grouting mechanism; The rotary jet grouting mechanism includes a slide (1), a front power head (2), a protective sleeve (3), a rear power head (4), a drill rod (5), and a drill bit. The front power head (2) and the rear power head (4) are slidably connected on the slide (1). The front power head (2) is detachably connected to the protective sleeve (3). The front power head (2) is used to drive the protective sleeve (3) to move in the front-back direction. The rear power head (4) is detachably connected to one end of the drill rod (5). The rear power head (4) is used to drive the drill rod (5) to rotate and move in the front-back direction. The drill rod (5) is coaxially arranged with the protective sleeve (3), and the outer diameter of the drill rod (5) is smaller than the inner diameter of the protective sleeve (3). The other end of the drill rod (5) is detachably connected to a drill bit, which includes a drilling drill bit (6) and a grouting drill bit (7). The azimuth adjustment mechanism includes a bracket (10), a support frame (11), a first power telescopic component (12), a rotating rod (13), a first gear (14), and a first rack (15). The bracket (10) is fixedly installed above the track walking mechanism (9). The support frame (11) is fixedly installed on the upper surface of the bracket (10). The support frame (11) is inverted "Ω" shape. The rotating rod (13) is rotatably connected inside the support frame (11). The first gear (14) is coaxially fixedly connected to the outer side wall of the rotating rod (13). The fixed end of the first power telescopic component (12) is fixedly connected to the upper surface of the bracket (10). The movable end of the first power telescopic component (12) is fixedly connected to the first rack (15). The first rack (15) is slidably connected to the upper surface of the bracket (10), and the first rack (15) meshes with the first gear (14). The process of using the drilling device: Install the drilling bit (6), install the drilling bit (6) on the other end of the drill rod (5), and slide the front power head (2) and the rear power head (4) to the rear end of the slide (1), so that the drill rod (5) is fitted inside the protective sleeve (3), and the drilling bit (6) is set through the protective sleeve (3), so that the drill rod (5) is set towards the drilling point; Drilling is performed by controlling the front power head (2) and the rear power head (4) to move simultaneously toward the front end of the slide (1). The drilling bit (6) drives the protective sleeve (3) to drill in the structural layer. Drilling stops after reaching the designed hole depth. The process of using the grouting device: Replace the grouting drill bit (7), control the rear power head (4) to slide to the rear end of the slide (1), replace the drilling drill bit (6) with the grouting drill bit (7), and control the rear power head (4) to slide to the front end of the slide (1) so that the grouting drill bit (7) penetrates the protective sleeve (3). The rotary jetting and retraction inject air and grout into the borehole through the drill rod (5) and grouting drill bit (7), and control the front power head (2) and rear power head (4) to make the wall casing (3) and grouting drill bit (7) withdraw from the borehole.

2. The horizontal drilling rotary jet grouting pile forming device according to claim 1, characterized in that, The drilling bit (6) includes an impactor (601) and an impact drill bit (602). When drilling, the other end of the drill rod (5), the impactor (601) and the impact drill bit (602) are detachably connected in sequence. The impactor (601) is installed through the protective sleeve (3). During grouting, the other end of the drill rod (5) is detachably connected to the grouting drill bit (7), which is installed through the protective sleeve (3).

3. The horizontal drilling rotary jet grouting pile forming device according to claim 2, characterized in that, The drill rod (5) is provided with an air injection channel (501) and a grouting channel (502). When drilling, the air injection channel (501) is selectively connected to the impactor (601). When grouting, the air injection channel (501) and the grouting channel (502) are selectively connected to the grouting drill bit (7).

4. The horizontal drilling rotary jet grouting pile forming device according to claim 3, characterized in that, The grouting drill bit (7) includes: an air inlet channel (701) selectively connected to the air injection channel (501); An air outlet (702) is provided along the radial direction of the grouting drill bit (7) and is connected to the air inlet channel (701); a grout inlet channel (703) is selectively connected to the grouting channel (502); and a grout outlet (704) is provided along the radial direction of the grouting drill bit (7) and is connected to the grout inlet channel (703).

5. The horizontal drilling rotary jet grouting pile forming device according to claim 4, characterized in that, The rotary jet grouting mechanism also includes a pipe shoe (8), which is a hollow ring structure. The outer wall of the pipe shoe (8) is stepped. The small diameter end of the pipe shoe (8) is detachably connected to the end of the protective sleeve (3) away from the front power head (2). The inner wall diameter of the pipe shoe (8) is smaller than the outer wall diameter of the drill rod (5). The inner wall diameter of the pipe shoe (8) is greater than or equal to the outer wall diameter of the impactor (601). The grouting drill bit (7) has an annular protrusion on its outer wall in the middle. The inner diameter of the annular protrusion is less than or equal to the inner diameter of the protective sleeve (3). The outer diameter of the annular protrusion is greater than the inner diameter of the pipe shoe (8).

6. The horizontal drilling rotary jet grouting pile forming device according to claim 5, characterized in that, The walking mechanism is a tracked walking mechanism (9); The elevation adjustment mechanism includes a second power telescopic member (18) and a third power telescopic member (19). The lower end of the second power telescopic member (18) is hinged to the rear end side wall of the rotating rod (13), and the upper end of the second power telescopic member (18) is hinged to the front end of the carriage (1). The lower end of the third power telescopic member (19) is hinged to the front end side wall of the rotating rod (13), and the upper end of the third power telescopic member (19) is hinged to the rear end of the carriage (1).

7. The horizontal drilling rotary jet grouting pile forming device according to claim 1, characterized in that, The front power head (2) and the rear power head (4) are detachably connected by fasteners.

8. A construction method based on the horizontal drilling rotary jet grouting pile forming device according to any one of claims 1-7, characterized in that, Includes the following steps: S1. Lay out the lines and mark the drilling points; S2. The wall-protecting sleeve (3) and drill rod (5) are installed. The wall-protecting sleeve (3) is installed on the front power head (2), and the drill rod (5) is installed on the rear power head (4). S3. Positioning: Control the walking mechanism to adjust the position of the jet grouting mechanism; control the azimuth adjustment mechanism to adjust the azimuth angle of the jet grouting mechanism; control the height and elevation adjustment mechanism to adjust the height and elevation angle of the jet grouting mechanism. S4. Install the drilling bit (6), install the drilling bit (6) on the other end of the drill rod (5), and slide the front power head (2) and the rear power head (4) to the rear end of the slide (1), so that the drill rod (5) is sleeved in the protective sleeve (3), and the drilling bit (6) is set through the protective sleeve (3), so that the drill rod (5) is set towards the drilling point. S5. Drilling: Control the front power head (2) and the rear power head (4) to move simultaneously toward the front end of the slide (1). The drilling bit (6) drives the protective sleeve (3) to drill in the structural layer. Drilling stops after reaching the designed hole depth. S6. Replace the grouting drill bit (7), control the rear power head (4) to slide to the rear end of the slide (1), replace the drilling drill bit (6) with the grouting drill bit (7), and control the rear power head (4) to slide to the front end of the slide (1) so that the grouting drill bit (7) penetrates the protective sleeve (3). S7. Spraying and retraction: Air and grout are injected into the borehole through the drill rod (5) and grouting drill bit (7), and the front power head (2) and rear power head (4) are controlled to make the wall casing (3) and grouting drill bit (7) withdraw from the borehole. S8. Seal the borehole opening; Repeat steps S3 to S8 until construction is complete.

9. The construction method of the horizontal drilling rotary jet grouting pile forming device according to claim 8, characterized in that, Step S5 also includes introducing air into the drilling bit (6) through the drill rod (5); In step S7, the front power head (2) and the rear power head (4) use an intermittent retraction method to withdraw the wall casing (3) and the grouting drill bit (7) from the borehole.

10. The construction method of the horizontal drilling rotary jet grouting pile forming device according to claim 9, characterized in that, In steps S5 and S7, the front power head (2) and the rear power head (4) are connected by fasteners; in the remaining steps, the front power head (2) and the rear power head (4) are not connected.

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