Three-dimensional rotary cutting mixing pile

Abstract

A three-dimensional rotary-cut mixing pile belongs to the technical field of soft foundation treatment construction. Its mixing drill bit is equipped with a bevel gear that meshes with a bevel gear at one end of the mixing shaft. The beneficial effects of the present invention are as follows: the core rod in the mixing drill bit meshes with a horizontal mixing shaft with a bevel gear through the bevel gear, thereby driving the mixing blades on the mixing shaft to rotate vertically. This, together with the horizontal stirring of the mixing blades on the mixing drill bit, achieves a three-dimensional cross-mixing function. Furthermore, the air pipe attached to the drill rod pumps high-pressure gas into the mixing soil, creating a gas explosion effect in the mixing soil, further enhancing the mixing effect on the soft foundation soil.

Description

Technical Field

[0001] The invention belongs to the field of building construction, and in particular relates to a three-dimensional rotary cutting mixing pile for soft foundation treatment. Background Art

[0002] The so-called soft soil refers to a weak soil layer with low strength and high compressibility, most of which contain certain organic matter. Due to the low strength and large amount of subsidence of soft soil, it often brings great harm to roadbed engineering. If it is not handled properly, it will have a great impact on the roadbed construction and use of railways (highways). Common soft soil in roadbed generally refers to clay soil in a soft or fluid state. Its characteristics are: high natural water content, large porosity, high compression coefficient, low strength, and special engineering geological properties such as creep and thixotropy. The engineering geological conditions are poor. For the reinforcement of roadbed in soft soil sections, practical reinforcement technical measures must be adopted.

[0003] Technical treatment methods for soft soil foundations include: replacement cushion method, drainage consolidation method, preloading method, dynamic compaction method, deep mixing method, etc. Among them, the deep mixing method is mainly used to consolidate saturated soft clay. It uses cement slurry as a curing agent. A special deep mixer is used to deliver the curing agent into the foundation soil and forcibly mix it with the soil to form a cement-soil pile, which forms a composite foundation with the original foundation.

[0004] The existing cement soil deep mixing pile machine has the following defects:

[0005] 1. The mixing device of the drill bit is two cross-shaped mixing teeth, and the number of revolutions of the drill rod is relatively low. When encountering highly viscous soil, there is a phenomenon of clay sticking to the mixing teeth and the drill rod, resulting in the mixing teeth being unable to effectively cut the soil, making it impossible to fully mix the slurry (curing agent) and soil, and even failing to crush the soil and fill it with cement slurry (curing agent). The on-site performance is that the cement (curing agent) content in the drill core sample is very low, and the formed cement mixing pile is not a pile, and its pile body strength does not meet the design requirements.

[0006] 2. There are generally two stirring methods: one-way stirring and multi-way stirring. The stirring methods are all horizontal and the stirring effect is poor. Summary of the Invention

[0007] The purpose of the present invention is to provide a three-dimensional rotary cutting and mixing pile. Through the construction of this construction device, the soft soil foundation and the curing agent can be quickly and fully mixed, thereby improving the strength and quality of the three-dimensional mixing and curing pile body.

[0008] The objective of the present invention is achieved through the following technical solutions: a three-dimensional rotary cutting mixing pile, comprising a stirring drill bit, a drill rod and a water joint connected in sequence, the bottom of the stirring drill bit is provided with a drill tip, a group of stirring blades are provided on the side wall of the stirring drill bit in the horizontal direction relative to the proximal end of the drill tip, a plurality of stirring shafts are connected to the side wall of the stirring drill bit from the distal end of the drill tip, each group of stirring shafts is relatively arranged, adjacent stirring shafts are not in the same plane, and are staggered with each other, a rotary cutting blade is provided on the stirring shaft, a slurry pipe and an air pipe are provided in the stirring drill bit and the drill rod, characterized in that: it also includes a bevel gear, a stopper and a core tube, the bevel gear is installed in the stirring drill bit, and meshes with the bevel gear at one end of the stirring shaft, a core tube is installed in the stirring drill bit, the core tube is inserted in the bevel gear, the top of the core tube is inserted into the bearing at the top of the stirring drill bit, and the bottom of the core tube is inserted in the stirring The drill bit is provided with a bearing on a fixed end, a core tube is installed in the drill rod, and the core tube is inserted into a bearing fixed to a bracket. The stopper is inserted into a bearing in a water joint. The stopper is provided with a core tube channel. The core tube channel has a slurry chamber at the top, and the core tube is installed at the bottom. A slurry tube extends from the top of the stopper into the slurry chamber, extends from the bottom of the slurry chamber, and is connected to the core tube. Slurry holes are provided on the wall of the slurry tube in the slurry chamber. The stopper is provided with a channel communicating with the slurry chamber. The slurry tube in the slurry chamber extends from the channel and extends into the slurry channel in the stopper. The slurry tube in the slurry channel, the slurry tube in the drill rod, and the slurry tube in the mixing drill bit are sequentially connected. The core tube in the stopper, the core tube in the drill rod, and the core tube in the mixing drill bit are sequentially connected. The stopper is provided with a gas channel, which is sequentially connected to the gas tube in the drill rod and the gas tube in the mixing drill bit. The mixing blade is straight or serrated.

[0009] The stirring blade is in a straight line shape or a sawtooth shape.

[0010] The extension line of the stirring blade forms an angle with the horizontal plane.

[0011] The distal end of the stirring blade is provided with a stirring blade perpendicular to the stirring blade.

[0012] The outlet of the slurry pipe is located on the stirring drill bit close to the stirring blade, and the outlet of the air pipe is located at the lowest end of the stirring shaft.

[0013] The beneficial effects of the present invention are:

[0014] 1. The bevel gear at one end of the mixing shaft of the three-dimensional rotary mixing pile meshes with the bevel gear on the core tube, so that the mixing blades can rotate in both horizontal and vertical directions. When gas is added, three-dimensional cross mixing is formed to improve the mixing efficiency and pile quality.

[0015] 2. Three-dimensional rotary cutting mixing piles, by adjusting the ratio of the conical gears on the core tube and the conical gears on the mixing shaft, the mixing shaft is accelerated. The corresponding speed is selected for mixing construction according to different soil types, which overcomes the shortcomings of traditional mixing piles with low speed and can only adapt to the stratum by changing the number of mixing and spraying. The three-dimensional mixing and curing pile mixing device effectively and quickly mixes cement soil evenly, overcoming the phenomenon of clay sticking to the mixing teeth and drill rod. The rotary cutting blades on the mixing shaft can effectively cut the soil, greatly improving the process adaptability to different strata, thereby ensuring the quality of the piles and meeting the design requirements.

[0016] 3. The core tube of the three-dimensional rotary mixing pile and the mixing shaft are engaged through bevel gears. The mechanical connection method ensures the high efficiency and reliability of the mixing function. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic structural diagram of the stirring drill bit of the present invention.

[0018] Figure 2 It is a schematic diagram of the drill rod structure of the present invention.

[0019] Figure 3 It is a schematic diagram of the top view of the connection structure between the stirring drill bit and the drill rod of the present invention.

[0020] Figure 4 It is a schematic structural diagram of the water connector and the stopper device of the present invention.

[0021] Figure 5 This invention Figure 4 Schematic diagram of the AA structure.

[0022] Figure 6 This invention Figure 4 Schematic diagram of the BB structure.

[0023] Figure 7 This invention Figure 4 Schematic diagram of CC structure.

[0024] Figure 8 It is a schematic diagram of the structure of the connection between the stop device and the drill rod in a bottom view according to the present invention.

[0025] Figure 9 It is a cross-sectional view of the connection between the stop device and the drill rod of the present invention.

[0026] in:

[0027] 1-mixing drill bit, 2-drill rod, 3-water joint, 4-core tube, 5-bearing, 6-mixing blade, 7-spraying port, 8-conical drill tip, 9-slotted mixing blade, 10-mixing shaft, 11-peeling blade, 12-conical gear, 13-core tube channel, 14-fixed end, 15-slurry pipe, 16-air pipe, 17-bracket, 18-lifting ear, 19-stop device, 20-bracket, 21-sealing ring, 22-flange, 23-slurry hole, 24-slurry cavity, 25-gas channel. DETAILED DESCRIPTION

[0028] Embodiment: A three-dimensional rotary cutting mixing pile includes a mixing drill bit 1, a drill rod 2 and a water joint 3;

[0029] The bottom of the mixing drill bit 1 is provided with a conical drill tip 8, and a group of mixing blades 9 are provided on the side wall of the mixing drill bit 1 in the horizontal direction relative to the proximal end of the drill tip 8. The mixing blades 9 can be straight or serrated. The mixing blades 9 form an inclined angle with the horizontal plane, and the distal end of the mixing blades 9 is provided with a mixing blade 6 perpendicular to the mixing blade 9. The distal end of the conical drill tip 8 on the side wall of the mixing drill bit 1 is connected to the mixing blade 6 by a bearing 5. Connect multiple groups of stirring shafts 10, each group of stirring shafts 10 is arranged relatively, adjacent stirring shafts 10 are not in the same plane, and are staggered with each other, and one or more groups of rotary cutting blades 11 are provided on the stirring shaft 10, and multiple bevel gears 12 are installed corresponding to the stirring shaft 10 in the stirring drill bit 1, and each bevel gear 12 is meshed with the bevel gear at one end of the stirring shaft 10. A core tube 4 is installed in the stirring drill bit 1, and the core tube 4 is inserted in the bevel gear 12. The top of the core tube 4 is connected to the top of the stirring drill bit 1 through a bearing 5, and the bottom is connected to the bearing 5 on the fixed end 14 in the stirring drill bit 1. A slurry pipe 15 and an air pipe 16 are provided in the stirring drill bit 1, and the outlet of the slurry pipe 15, i.e., the spraying port 7, is located on the stirring drill bit 1 near the stirring blade 9, and the outlet of the air pipe 16 is located at the lowest end of the stirring shaft 10;

[0030] The drill rod 2 is connected to the mixing drill bit 1 through a flange 22. A core tube 4, a slurry tube 15 and an air tube 16 are provided in the drill rod 2. A plurality of brackets 17 are fixed from top to bottom in the drill rod 2. A bearing 5 is installed on each bracket 17. The core tube 4 is inserted into the bearing 5.

[0031] The water joint 3 is fixed on the lifting ear 18, and the stopper 19 is installed in the water joint 3. The stopper 19 is connected to the drill pipe 2 through the flange 22. A bracket 20 is installed in the water joint 3, and a bearing 5 is installed above and below the bracket 20. The stopper 19 is inserted in the bearing 5. The upper and lower ends of the bearing 5 are sealed by a sealing ring 21 respectively. A core pipe channel 13 is provided in the stopper 19, and a slurry cavity 24 is provided at the upper part of the core pipe channel 13. The core pipe 4 is installed at the lower part. The slurry pipe 15 extends into the slurry cavity 24 from the top of the slurry cavity 24, extends from the bottom of the slurry cavity 24, and is connected to the core pipe 4. The upper and lower ends of the slurry cavity 24 are respectively installed with sealing rings 21. Sealed, the upper end of the slurry pipe 15 is inserted in the bearing 5 at the top of the stopper 19, and the connecting end of the core pipe 16 connected to the slurry pipe 15 is inserted in the bearing 5. Slurry holes 23 are provided on the wall of the slurry pipe 15 in the slurry cavity 24. The side wall of the stopper 19 is provided with a channel communicating with the slurry cavity 24. The slurry pipe 15 extends from the channel and extends into the slurry channel of the stopper 19, and is connected to the slurry pipe in the drill rod 2 and the slurry pipe in the stirring drill bit 1 in sequence. The core pipe 4 in the stopper 19 is connected to the core pipe in the drill rod 2 and the core pipe in the stirring drill bit 1 in sequence. A gas channel 25 is provided on the bracket 20, which is connected to the gas channel 25 in the stopper 19. One end of the gas channel 25 is connected to the air pipe 16 provided on the outer side wall of the water joint 3, and the other end of the gas channel 25 is connected downward to the air pipe in the drill rod 2 and the air pipe in the stirring drill bit 1 in sequence.

[0032] Working principle:

[0033] Place the device at the pile position in the foundation, start the device and drill to the designed pile bottom depth. During this process, the air pipe sprays gas into the soil to assist in stirring the soil when the mixing drill bit stirs the soil. Spray grout and lift the mixing drill bit. Under the action of the straight mixing blade and the rotary cutting blade, the cement slurry and soil are fully and evenly mixed. The drill bit is raised to the designed pile top height and the spraying is stopped. Drill again and mix to the designed pile bottom depth. Repeat the spraying, stirring and lifting of the drill rod to complete the pile construction.

[0034] Under the rotation of the stirring drill bit, the core tube of this device does not rotate. Through the meshing action of the core tube and the bevel gear on the stirring shaft, the stirring shaft can rotate horizontally and vertically, stirring and cutting the soil, and the slurry and soil are fully and evenly mixed.

[0035] The device meshes the bevel gears on the core tube 4 with the stirring shaft 10, and the mechanical connection method ensures the high efficiency and reliability of the stirring function; by changing the module of the bevel gear, the number of rotations of the stirring shaft driven by the drill rod is changed, and the rotation speed of the stirring shaft is increased, the cement soil is effectively and quickly stirred evenly, overcoming the phenomenon of clay sticking to the stirring teeth and drill rod. The rotary cutting blades on the stirring shaft can effectively cut the soil, greatly improving the process adaptability to different strata, thereby ensuring the quality of pile formation and meeting design requirements.

[0036] The construction effect after using this device was compared with the traditional process. The results are shown in the following table:

[0037]

[0038] Through the above comparison, the use of this device for construction has the following advantages over other devices and methods:

[0039] 1. High reliability of mechanical transmission

[0040] The mixing shaft is meshed with bevel gears and its power is provided by the pile driver. The speed of the mixing shaft (peeling blade) can be changed by the different speeds of the pile driver to adapt to different soil types and better mix the soil.

[0041] 2. High-speed rotating rotary cutting blades provide good mixing quality:

[0042] Under the mixing action of the high-speed rotating rotary cutting blade, the soil and curing agents such as cement can be fully mixed, making the soil and curing agent mixed more evenly, thereby ensuring the quality of the pile.

[0043] 3. Gas explosion helps to stir the soil:

[0044] The gas that provides power to the pneumatic device enters the soil at the drill bit, which helps to mix the soil and the curing agent. When the pile is long and the drill bit is deep in the soil, spraying is difficult due to the soil pressure. After the gas is introduced, the effect of gas explosion makes spraying and mixing easier, thereby improving the quality of the pile.

[0045] 4. Adapt to a wide range of soil types:

[0046] Soil types such as silty soil, clay soil, and silty clay with a large plasticity index are difficult to mix into piles. By adjusting the construction parameters, the above soil types can be fully and effectively mixed with cement slurry and other curing agents under the combined action of the rotary cutting blades and gas explosion of the three-dimensional mixing and curing pile driver, thereby solving the problem of traditional cement mixing piles failing to form piles in silty soil, clay soil, and silty clay with a large plasticity index.

[0047] 5. Higher pile quality:

[0048] When there are multiple layers of soil or uneven soil layers within the reinforcement range, compared with traditional cement mixing pile drivers, under the same conditions of equipment speed, drilling speed, shotcrete volume and other construction parameters, the three-dimensional mixing and curing pile driver's high-speed rotating rotary cutting blades perform three-dimensional forced mixing, and the uniformity, integrity and pile body strength of the piles are significantly improved.

Claims

1. A three-dimensional rotary cutting mixing pile, comprising a stirring drill bit, a drill rod and a water joint connected in sequence, wherein the bottom of the stirring drill bit is provided with a drill tip, a group of stirring blades are provided on the side wall of the stirring drill bit in a horizontal direction relative to the proximal end of the drill tip, and multiple groups of stirring shafts are connected to the side wall of the stirring drill bit from the distal end of the drill tip, each group of stirring shafts is arranged opposite to each other, adjacent stirring shafts are not in the same plane, and are staggered with each other, and the stirring shafts are provided with rotary cutting blades, and the stirring drill bit and the drill rod are provided with a slurry pipe and an air pipe, characterized in that: It also includes a bevel gear, a stopper and a core tube, wherein the bevel gear is installed in the stirring drill bit and meshes with the bevel gear at one end of the stirring shaft; the core tube is installed in the stirring drill bit, the core tube is inserted in the bevel gear, the top of the core tube is inserted into the bearing at the top of the stirring drill bit, and the bottom of the core tube is inserted in the bearing on the fixed end head in the stirring drill bit; the core tube is installed in the drill rod, the core tube is inserted in the bearing fixed on the bracket, and the stopper is inserted in the bearing in the water joint; a core tube channel is provided in the stopper, a slurry cavity is provided at the upper part of the core tube channel, a core tube is installed at the lower part, the slurry tube extends into the slurry cavity from the top of the stopper, extends from the bottom of the slurry cavity, and is connected to the core tube, and slurry tube walls in the slurry cavity are provided with slurry tubes at intervals Liquid hole, the stopping device is provided with a channel connected to the slurry chamber, the slurry pipe in the slurry chamber extends from the channel and extends into the slurry channel in the stopping device, the slurry pipe in the slurry channel, the slurry pipe in the drill rod, and the slurry pipe in the stirring drill bit are connected in sequence, the core pipe in the stopping device, the core pipe in the drill rod, and the core pipe in the stirring drill bit are connected in sequence, a bracket is installed in the water joint, bearings are installed above and below the bracket, the stopping device is inserted in the bearing, the upper and lower ends of the bearing are sealed by sealing rings respectively, a gas channel is provided on the bracket, which is connected to the gas channel in the stopping device, one end of the gas channel is connected to the air pipe arranged on the outer wall of the water joint, and the other end of the gas channel is connected downward to the air pipe in the drill rod and the air pipe in the stirring drill bit.

2. The three-dimensional rotary cutting and mixing pile according to claim 1, characterized in that: The stirring blade is in a straight line shape or a sawtooth shape.

3. The three-dimensional rotary cutting and mixing pile according to claim 1, characterized in that: The extension line of the stirring blade forms an angle with the horizontal plane.

4. The three-dimensional rotary cutting and mixing pile according to claim 1, characterized in that: The distal end of the stirring blade is provided with a stirring blade perpendicular to the stirring blade.

5. The three-dimensional rotary cutting and mixing pile according to claim 1, characterized in that: The outlet of the slurry pipe is located on the stirring drill bit close to the stirring blade, and the outlet of the air pipe is located at the lowest end of the stirring shaft.

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