A drill for large-diameter multi-layer inter-shearing mixing pile construction

Abstract

The present application relates to the technical field of stirring drilling tools, and a drilling tool for large-diameter multi-layer inter-shearing stirring pile construction, comprising an outer rod, an inner rod, at least two stirring wings and a digging wing plate; at least one inner rod slurry channel is arranged in the inner rod; at least one stirring wing is radially distributed on the outer sidewall of the central axis of the outer rod; at least one stirring wing is radially distributed on the outer sidewall of the central axis of the inner rod; the stirring wings in the same layer rotate with the outer rod or rotate with the inner rod in the same direction; there is at least one fixed connection point between the stirring wing and the rod rotating in the same direction, and when the stirring wing is connected with the rod rotating in the opposite direction, the stirring wing and the rod are both rotationally connected; the digging wing plate is arranged at the bottom of the inner rod or the bottom of the outermost stirring wing. The present application has the advantages of solving the problems of limited stirring area and poor inter-shearing effect of the stirring wings caused by consistent stirring wing trajectories, and can realize greater disturbance of the soil body and achieve more sufficient and uniform stirring effect.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of stirring drilling tools, and particularly relates to a drilling tool for large-diameter multi-layer inter-shearing stirring pile construction. BACKGROUND

[0002] As a main method in the technical field of foundation treatment engineering, deep stirring pile technology has been widely applied to the field of engineering construction since the 1960s, including the fields of civil engineering, construction engineering, railway engineering, highway engineering, water conservancy engineering, municipal engineering and port engineering. The deep stirring pile engineering technology uses a single-shaft or multi-shaft stirring drilling machine to input a solidifying agent such as cement into the ground, and through stirring and mixing with the soil, a series of physical and chemical reactions between the solidifying agent and the soil are generated, and a pile, a wall or a block with high strength, good water stability and strong anti-seepage performance is generated. Thus, the bearing capacity of the composite foundation, the bearing capacity of the stirring pile, the bearing capacity of the reinforced composite pile and the bearing capacity of the SMW method pile are effectively improved, and the practical engineering problems such as the anti-seepage force of the water isolation wall and the sealing wall and sealing layer of the contaminated soil and toxic substance landfill site are solved.

[0003] Due to the advantages of deep mixing pile engineering technology such as simple drilling equipment, efficient construction and low cost, it has been widely used in the field of civil construction. However, the commonly used mixing pile construction drill is designed with straight mixing blades on the center rod of the drill or with a grouting port on the center rod of the drill. This type of drill uses mixing blades to mix the sprayed solidifying agent slurry with the soil to form a mixing pile of a certain diameter. When the diameter of the pile foundation is small, the mixing requirement can still be met. However, when a large-diameter and deep mixing pile construction is required, the mixing ability of the straight mixing blades is insufficient, the mixing effect is poor, and the amount of solidifying agent slurry required per unit length of the pile body increases exponentially. The slurry around the center rod of the drill bit is difficult to reach each point of the pile foundation section, especially the peripheral area, through soil mixing and disturbance. Because it cannot disperse, the solidifying agent slurry often returns along the gap between the drill and the drill rod, the solidifying agent accumulates in some areas, especially the central area, and eventually causes the strength of the peripheral cement-soil to be much lower than that of the central cement-soil or even no strength, the overall strength of the solidified soil is lower than the design value, and other serious engineering quality problems occur, which often leads to serious engineering safety problems. At the same time, a large-diameter mixing pile requires a large-power and large-flow slurry pump, which increases the cost of equipment. Therefore, when using the mixing drill designed with conventional slurry conveying channels and grouting ports, the engineering quality and engineering safety risk are particularly prominent, and the engineering cost increases significantly. The current civil construction market urgently needs to solve the above engineering technical problems. Some conventional solutions are mainly as follows: 1. Increase the grouting pressure to use the jet flow to send the slurry to the outside of the pile body, or increase the amount of cement slurry, but these methods require additional equipment or increase the amount of materials, which increases the construction cost; 2. Increase the number of mixing blades or use four mixing and two grouting or multiple mixing and multiple grouting processes to increase the mixing time, which improves the uniformity to some extent, but reduces the construction efficiency and increases the mixing resistance, which greatly increases the power requirement of the power head equipment and the strength requirement of the drill rod and drill bit, affecting the construction feasibility. Therefore, the current mixing pile construction drill still has the problems of limited peripheral mixing capacity and poor mixing effect. SUMMARY

[0004] The purpose of the present application is to overcome the deficiencies of the prior art and provide a large-diameter multi-layer inter-shearing mixing pile construction drill. The drill uses mixing wings that rotate with the inner and outer rods to solve the problems of limited peripheral mixing capacity and poor mixing effect, and can achieve shear mixing with fewer mixing times than conventional mixing methods, achieving uniform mixing and greatly reducing the strength difference and improving the overall strength of the mixing pile. This structure can make the construction diameter of the mixing pile reach 1500-3000mm or even larger.

[0005] For the purpose of the present application, the following technical solutions are used to achieve it:

[0006] A drill for large-diameter multi-layer inter-shearing mixing pile construction, comprising an outer rod, an inner rod, at least two mixing wings, and multiple excavating wing plates; at least one inner rod slurry passage is arranged in the inner rod; the outer rod is rotationally connected to the inner rod; at least one mixing wing is radially distributed on the outer sidewall of the central axis of the outer rod; at least one mixing wing is radially distributed on the outer sidewall of the central axis of the inner rod; the mixing wings on the outer rod and the mixing wings on the inner rod are arranged in layers from the inside to the outside and do not interfere with each other when rotating; the mixing wings in the same layer rotate with the outer rod or rotate with the inner rod in the same direction; there is at least one fixed connection point between the mixing wings and the rod rotating in the same direction, and when the mixing wings are connected with the rod rotating in the opposite direction at the same time, the mixing wings and the rod are both rotationally connected; multiple excavating wing plates are arranged at the bottom of the inner rod or the bottom of the outermost mixing wing. Compared with the prior art, the drill structure solves the problems of limited peripheral mixing capacity of the mixing pile and poor mixing effect by adopting the design of mixing wings rotating with the inner and outer rods, and can realize less shear mixing than the conventional mixing method, that is, it can achieve uniform mixing effect, thereby greatly reducing the strength difference of the pile body and greatly improving the overall strength. Using this structure, the construction diameter of the mixing pile can reach 1500-3000 mm or even larger. And through multiple inner rod slurry passages, multiple channels can be realized under the condition that the amount of solidifying agent slurry required per unit depth is certain, and then the solidifying agent slurry is uniformly spread on each circumference of the pile cross section through the grouting joint, and the multiple circumferential superposition effect covers the entire pile cross section, thereby achieving uniform spreading of the solidifying agent on the entire cross section of the large-diameter pile. At the same time, through the different positions of the excavating wing plates, the drilling and excavating effect of the drill in the soil can be improved, the construction efficiency of the drilling machine can be improved, and the power consumption of the drilling machine can be reduced.

[0007] As a preferred, it further comprises a grouting excavating drill bit connected at the bottom of the inner rod, and the grouting excavating drill bit is provided with a drill bit grouting passage in communication with the inner rod slurry passage; when the excavating wing plate is located at the bottom of the inner rod, multiple excavating wing plates are arranged in a circumferential interval on the outer circumferential wall of the grouting excavating drill bit. Through the grouting excavating drill bit, the excavating effect can be further improved, and the grouting effect can be further improved.

[0008] As a preferred, the direction of the plate surface of the excavating wing plate and the transverse direction of the grouting excavating drill bit form an angle θ, and θ ranges from 0 to 45°. Through the above structure, better shear disturbance effect can be generated on the soil in front of the rotating direction, and the increased resistance of the drill bit is reduced.

[0009] As preferred, the jetting pipe is further provided with a jetting slot on the outer wall thereof; when the excavating wing plate is located at the bottom of the inner rod, a plurality of excavating wing plates are arranged in a circumferential interval on the outer circumferential wall of the jetting excavating drill bit; the jetting pipe is arranged at the bottom of the excavating wing plate, and the jetting pipe is communicated with the inner rod jetting channel; when the excavating wing plate is located at the bottom of the outermost stirring wing, and the outermost stirring wing is driven by the inner rod, a plurality of excavating wing plates are arranged in a radial interval at the bottom of the outermost stirring wing; the jetting pipe is arranged at the bottom of the excavating wing plate, and the jetting pipe is communicated with the inner rod jetting channel; when the excavating wing plate is located at the bottom of the outermost stirring wing, and the outermost stirring wing is driven by the outer rod, a plurality of excavating wing plates are arranged in a radial interval at the bottom of the outermost stirring wing; the jetting pipe is arranged at the bottom of the stirring wing driven by the inner rod, and the jetting pipe is communicated with the inner rod jetting channel. Through the jetting pipe corresponding to the position of different structures, stable jetting can be further performed during stirring, and the stirring uniformity is improved.

[0010] As preferred, the jetting slot is arranged in the shadow area of the jetting rotating earth surface at the bottom of the jetting excavating drill bit. This structure can effectively prevent the soil from entering the jetting channel, and ensure smooth jetting.

[0011] As preferred, the jetting pipe is further provided with a jetting slot on the outer wall thereof; when the excavating wing plate is located at the bottom of the inner rod, a plurality of excavating wing plates are arranged in a circumferential interval on the outer circumferential wall of the jetting excavating drill bit; the jetting pipe is arranged at the bottom of the excavating wing plate, and the jetting pipe is communicated with the inner rod jetting channel; when the excavating wing plate is located at the bottom of the outermost stirring wing, and the outermost stirring wing is driven by the inner rod, a plurality of excavating wing plates are arranged in a radial interval at the bottom of the outermost stirring wing; the jetting pipe is arranged at the bottom of the excavating wing plate, and the jetting pipe is communicated with the inner rod jetting channel; when the excavating wing plate is located at the bottom of the outermost stirring wing, and the outermost stirring wing is driven by the outer rod, a plurality of excavating wing plates are arranged in a radial interval at the bottom of the outermost stirring wing; the jetting pipe is arranged at the bottom of the stirring wing driven by the inner rod, and the jetting pipe is communicated with the inner rod jetting channel. Through the jetting pipe corresponding to the position of different structures, stable jetting can be further performed during stirring, and the stirring uniformity is improved.

[0012] As preferred, the jetting pipe is further provided with a jetting slot on the outer wall thereof; when the excavating wing plate is located at the bottom of the inner rod, a plurality of excavating wing plates are arranged in a circumferential interval on the outer circumferential wall of the jetting excavating drill bit; the jetting pipe is arranged at the bottom of the excavating wing plate, and the jetting pipe is communicated with the inner rod jetting channel; when the excavating wing plate is located at the bottom of the outermost stirring wing, and the outermost stirring wing is driven by the inner rod, a plurality of excavating wing plates are arranged in a radial interval at the bottom of the outermost stirring wing; the jetting pipe is arranged at the bottom of the excavating wing plate, and the jetting pipe is communicated with the inner rod jetting channel; when the excavating wing plate is located at the bottom of the outermost stirring wing, and the outermost stirring wing is driven by the outer rod, a plurality of excavating wing plates are arranged in a radial interval at the bottom of the outermost stirring wing; the jetting pipe is arranged at the bottom of the stirring wing driven by the inner rod, and the jetting pipe is communicated with the inner rod jetting channel. Through the jetting pipe corresponding to the position of different structures, stable jetting can be further performed during stirring, and the stirring uniformity is improved.

[0013] As preferred, when the stirring wing is double-layer distributed, the following two installation modes are included; the first mode: the inner stirring wing is arranged on the inner rod, and is driven to rotate and stir by the inner rod; the outer stirring wing is arranged on the outer rod, and is driven to rotate and stir by the outer rod; the second mode: the inner stirring wing is arranged on the outer rod, and is driven to rotate and stir by the outer rod; the outer stirring wing is arranged on the inner rod, and is driven to rotate and stir by the inner rod. Different forms of drill bit styles are realized through different numbers of stirring wings, different requirements and diversity are realized.

[0014] As preferred, when the stirring wings are distributed in three layers, the following five installation modes are included; the first mode: the stirring wings of the inner layer are driven to rotate and stir by the inner rods; the stirring wings of the middle layer are driven to rotate and stir by the outer rods; the stirring wings of the outer layer are driven to rotate and stir by the inner rods; the second mode: the stirring wings of the inner layer are driven to rotate and stir by the outer rods; the stirring wings of the middle layer are driven to rotate and stir by the inner rods; the stirring wings of the outer layer are driven to rotate and stir by the outer rods; the third mode: the stirring wings of the inner layer are driven to rotate and stir by the outer rods; the stirring wings of the middle layer are driven to rotate and stir by the inner rods; the stirring wings of the outer layer are driven to rotate and stir by the inner rods; the fourth mode: the stirring wings of the inner layer are driven to rotate and stir by the inner rods; the stirring wings of the middle layer are driven to rotate and stir by the inner rods; the stirring wings of the outer layer are driven to rotate and stir by the outer rods; the fifth mode: the stirring wings of the inner layer are simultaneously arranged on the inner rods and the outer rods, and are driven to rotate and stir by the inner rods and the outer rods respectively; the stirring wings of the middle layer are driven to rotate and stir by the inner rods; the stirring wings of the outer layer are driven to rotate and stir by the outer rods. Different forms of drilling tools are realized by different numbers of stirring wings, different requirements and diversity are realized.

[0015] As preferred, when the stirring wings are distributed in four layers, the following two installation modes are included; the first mode: the stirring wings of the inner layer are driven to rotate and stir by the inner rods; the stirring wings of the middle inner layer are driven to rotate and stir by the outer rods; the stirring wings of the middle outer layer are driven to rotate and stir by the inner rods; the stirring wings of the outer layer are driven to rotate and stir by the outer rods; the second mode: the stirring wings of the inner layer are driven to rotate and stir by the outer rods; the stirring wings of the middle inner layer are driven to rotate and stir by the inner rods; the stirring wings of the middle outer layer are driven to rotate and stir by the outer rods; the stirring wings of the outer layer are driven to rotate and stir by the inner rods. Different forms of drilling tools are realized by different numbers of stirring wings, different requirements and diversity are realized.

[0016] In summary, the advantages of the present application are that by adopting such a drilling tool stirring structure, the problems of limited stirring area caused by consistent stirring wing trajectory, poor mutual shearing effect of stirring wings and the like are solved, a larger range of soil disturbance can be realized, the stirring time is consistent compared with conventional stirring methods, but the stirring is more sufficient and uniform, thereby the strength difference of the pile body of the stirring pile is greatly reduced and the overall strength is greatly improved, in addition, the drilling tool form can well avoid the problems of co-rotation of the viscous soil wrapped around the drill bit and the easy residual soil in the gap area between the inner and outer stirring wings during the drilling. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is the overall structure diagram of the drilling tool provided with double-layer stirring wings of the present application.

[0018] Figure 2 is the structure section view diagram of the drilling tool provided with double-layer stirring wings of the present application.

[0019] Figure 3 is the overall structure of the present invention with double-layer mixing wings (the jetting pipe is located on the mixing wings).

[0020] Figure 4 is the partial structure of the present invention with double channels of the parameter drill bit.

[0021] Figure 5 is the partial structure of the present invention with double channels of the drill bit and the bottom jetting coverage range.

[0022] Figure 6 is the partial structure of the present invention with double channels of the drill bit and the bottom jetting coverage range.

[0023] Figure 7 is the jetting pipe and the jetting seam position profile of the present invention.

[0024] Figure 8 is the jetting pipe and the jetting seam position profile of the present invention.

[0025] Figure 9 is the jetting pipe and the jetting seam position profile of the present invention.

[0026] Figure 10 is the overall structure of the present invention with three-layer mixing wings.

[0027] Figure 11 is the overall structure of the present invention with three-layer mixing wings.

[0028] Figure 12 is the partial structure of the present invention with three channels of the parameter drill bit.

[0029] Figure 13 is the partial structure of the present invention with three channels of the parameter drill bit.

[0030] Figure 14 is the mixing wing setting illustration of the present invention.

[0031] Wherein: 1, outer rod; 101, outer rod connector; 2, inner rod; 201, inner rod connector; 3, stirring wing; 3-1, first layer stirring wing; 3-2, second layer stirring wing; 3-3, third layer stirring wing; 3-4, fourth layer stirring wing; 4, inner rod slurry channel; 5, slurry jetting and excavating drill bit; 501, drill bit connector; 502, drill bit center rod; 51, drill bit slurry channel; 6, excavating wing plate; 61, slurry jetting pipe; 61-1, first slurry jetting pipe; 61-2, second slurry jetting pipe; 61-3, third slurry jetting pipe; 610, slurry jetting pipe channel; 611, rodless slurry stopping screw plug; 612, rod slurry stopping screw plug; 6122, screw plug thread; 6123, inner hexagonal hole; 62, slurry jetting seam; 621, slurry jetting pipe thread; 62-1, first slurry jetting seam; 62-2, second slurry jetting seam; 62-3, third slurry jetting seam; 63, first excavating tooth; 64, spiral wing plate; 65, second excavating tooth; 7, shadow area; 100, outer drill rod; 200, inner drill rod; 300, inner drill rod channel. DETAILED DESCRIPTION

[0032] In order to make the above-mentioned objectives, features and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0033] As Figures 1 to 14As shown, a drill for large-diameter multi-layer inter-shearing mixing pile construction includes an outer rod 1, an inner rod 2, at least two mixing wings 3, and multiple excavation wing plates 6; the outer rod 1 is connected with an outer drill rod 100 through an outer rod connector 101; the inner rod 2 is connected with an inner drill rod 200 through an inner rod connector 201, and at least one inner drill rod passage 300 is arranged in the inner drill rod 200; the inner rod 2 is provided with inner rod slurry passages 4 corresponding to the number of the inner drill rod passages 300; the outer rod 1 is rotationally connected to the inner rod 2; at least one mixing wing 3 is radially distributed on the outer sidewall of the central axis of the outer rod 1; at least one mixing wing 3 is radially distributed on the outer sidewall of the central axis of the inner rod 2, and the mixing wings 3 on the outer rod 1 and the mixing wings 3 on the inner rod 2 are arranged in layers and do not interfere with each other when rotating; the mixing wings 3 in the same layer rotate with the outer rod 1 or rotate with the inner rod 2 in the same direction, and there is at least one fixed connection point between the mixing wings 3 and the rod members rotating in the same direction, and when the mixing wings 3 are connected with rod members rotating in opposite directions, the mixing wings 3 and the rod members are rotationally connected; the multiple excavation wing plates 6 are arranged at the bottom of the inner rod 2 or the bottom of the outermost mixing wing 3. Compared with the prior art, the drill structure solves the problems of limited peripheral mixing capacity of the mixing pile and poor mixing effect by adopting the design of mixing wings rotating with the inner and outer rods, and can realize less shear mixing than the conventional mixing method, that is, the mixing is uniform, thereby greatly reducing the strength difference of the pile body and greatly improving the overall strength. Using this structure, the construction diameter of the mixing pile can reach 1500-3000mm or even larger. And through multiple inner rod slurry passages 4, multiple channels can be realized under the condition that the amount of solidifying agent slurry required per unit depth is certain, and then the solidifying agent slurry is uniformly spread on each circumference of the pile cross section through the grouting joint 62, and the multiple circumferential superposition effect covers the entire pile foundation cross section, thereby achieving uniform spreading of the solidifying agent on the entire cross section of the large-diameter pile. At the same time, through the different positions of the excavation wing plates, the drilling and excavation effect of the drill in the soil can be improved, the construction efficiency of the drilling machine can be improved, and the power consumption of the drilling machine can be reduced.

[0034] Based on the working mode of the mixing wing 3, various different structures can be configured: when the mixing wing 3 is arranged in two layers, for example, Figure 14 (a)-(e); two installation modes are formed; the first mode is, for example Figure 14 (a): the inner layer mixing wing 3 is arranged on the inner rod 2 and driven to rotate for mixing by the inner rod 2; the outer layer mixing wing 3 is arranged on the outer rod 1 and driven to rotate for mixing by the outer rod 1; the second mode is, for example Figure 14(b): the stirring wings 3 of the inner layer are arranged on the outer rod 1 and driven to rotate and stir by the outer rod 1; the stirring wings 3 of the outer layer are arranged on the inner rod 2 and driven to rotate and stir by the inner rod 2. The stirring wings can be in the form of stirring blades or in the form of stirring frames. Different forms of drilling tools are realized by different forms of stirring wings, and different requirements and diversity are realized.

[0035] When the stirring wings 3 are arranged in three layers, the following five modes are included: the first mode: the stirring wings 3 of the inner layer are driven to rotate and stir by the inner rod 2; the stirring wings 3 of the middle layer are driven to rotate and stir by the outer rod 1; the stirring wings 3 of the outer layer are driven to rotate and stir by the inner rod 2; the second mode is, for example Figure 14 (h): the stirring wings 3 of the inner layer are driven to rotate and stir by the outer rod 1; the stirring wings 3 of the middle layer are driven to rotate and stir by the inner rod 2; the stirring wings 3 of the outer layer are driven to rotate and stir by the outer rod 1. The third mode: the stirring wings 3 of the inner layer are driven to rotate and stir by the outer rod 1; the stirring wings 3 of the middle layer are driven to rotate and stir by the inner rod 2; the stirring wings 3 of the outer layer are driven to rotate and stir by the inner rod 2; the fourth mode is, for example Figure 14 (i): the stirring wings 3 of the inner layer are driven to rotate and stir by the inner rod 2; the stirring wings 3 of the middle layer are driven to rotate and stir by the inner rod 2; the stirring wings 3 of the outer layer are driven to rotate and stir by the outer rod 1. The fifth mode is, for example Figure 14 (g), (j) and (m) shown, the stirring wings 3 of the inner layer are arranged on the inner rod 2 and the outer rod 1 respectively, and are driven to rotate and stir by the inner rod 2 and the outer rod 1 respectively; the stirring wings 3 of the middle layer are driven to rotate and stir by the inner rod 2; the stirring wings 3 of the outer layer are driven to rotate and stir by the outer rod 1. Different forms of drilling tools are realized by different numbers of stirring wings, and different requirements and diversity are realized.

[0036] When the stirring wings 3 are arranged in four layers, the following two installation modes are included: the first mode: the stirring wings 3 of the inner layer are driven to rotate and stir by the inner rod 2; the stirring wings 3 of the middle inner layer are driven to rotate and stir by the outer rod 1; the stirring wings 3 of the middle outer layer are driven to rotate and stir by the inner rod 2; the stirring wings 3 of the outer layer are driven to rotate and stir by the outer rod 1; the second mode: the stirring wings 3 of the inner layer are driven to rotate and stir by the outer rod 1; the stirring wings 3 of the middle inner layer are driven to rotate and stir by the inner rod 2; the stirring wings 3 of the middle outer layer are driven to rotate and stir by the outer rod 1; the stirring wings 3 of the outer layer are driven to rotate and stir by the inner rod 2. There can also be different driving modes, for example, the stirring wings 3 are driven from inside to outside by the inner rod 2, the outer rod 1, the inner rod 2, the inner rod 2, or the inner rod 2, the outer rod 1, the outer rod 1, the inner rod 2, or the inner rod 2, the outer rod 1, the outer rod 1, the outer rod 1, or the inner rod 2, the inner rod 2, the outer rod 2, the inner rod 2, or the inner rod 2, the inner rod 2, the inner rod 2, the outer rod 1, etc.

[0037] As Figure 14(d) shows that the first layer of stirring wings 3-1 has one fixed connection point with the outer rod 1 and more than one rotating connection point with the inner rod 2; as Figure 14 (h) shows that the third layer of stirring wings 3-3 has two fixed connection points with the outer rod 1; in addition, comparing Figure 14 (a) with Figure 14 (b) the first layer of stirring wings 3-1 of the drill structure, and Figure 14 (h) the third layer of stirring wings 3-3 of the drill structure in figure (i), it can be seen that the stirring wings 3 in the same layer can be arranged to rotate with the outer rod 1 or with the inner rod 2; further, comparing Figure 14 (k) with Figure 14 (m) the third layer of stirring wings 3-3 and the fourth layer of stirring wings 3-4 of the drill, it can be seen that the layered arrangement of the stirring wings 3 can be a nested layered arrangement or a parallel layered arrangement. As Figure 14 (n) shows that the stirring wings 3 can be arranged to be staggered with the inner and outer rods; compared with the prior art, the opposite rotating motion of the multi-layer stirring wings forms mutual shearing of the soil layers, enhancing the stirring disturbance effect and providing stirring conditions for more uniform distribution of the solidifying agent in the soil. In addition, the stirring wings 3 that are fixedly connected to more inner rods 2 or outer rods 1 are subjected to greater torque, based on which, the rotating direction of the stirring wings 3 can be flexibly allocated and adjusted according to the torque size of the inner rods 2 and the outer rods 1 and the power of the power driving device.

[0038] As Figure 14 shown, the trajectories formed by the rotation of different stirring wings 3 in the same layer by 360° can coincide, partially coincide, or not coincide at all. As Figure 14 (a), 14(b) shows the second layer of stirring wings 3-2, Figure 14 (g) shows the third layer of stirring wings 3-3, due to the different heights of the arrangement positions of the stirring wings 3, the rotating trajectories do not coincide at all; as Figure 14 (f) shows that the second layer of stirring wings 3-2 partially coincides due to the shape difference; as Figure 14 (g) shows that the second layer of stirring wings 3-2 partially coincides due to the existence of branch structures at different positions in the body; as Figure 14As shown in (i), the first layer of mixing blades 3-1 have completely different shapes, resulting in non-overlapping rotation trajectories. Compared with existing technologies, by adopting this type of drilling tool mixing structure, the problems of limited mixing area caused by the consistent trajectory of mixing blades 3 and poor mutual shearing effect of mixing blades 3 are solved. It can achieve a larger range of soil disturbance, achieve a mixing time that is consistent with conventional mixing methods, and achieve a more thorough and uniform mixing effect. This leads to a significant reduction in the strength difference of the mixing pile body and a significant increase in the overall strength. In addition, this type of drilling tool can effectively avoid the problem of cohesive soil wrapping around the drill bit and causing co-rotation, as well as the problem of soil residue easily remaining in the gap area between the inner and outer mixing blades 3 when the drill is lifted.

[0039] At least one inner rod 2 has an inner rod slurry passage 4, such as Figure 2 As shown, this embodiment includes two inner rod grouting channels 4, a grouting excavation drill bit 5, and a grouting pipe 61. The grouting excavation drill bit 5 includes a drill bit connector 501 and a drill bit center rod 502. The drill bit center rod 502 is fixedly connected to the drill bit connector 501. The grouting excavation drill bit 5 is connected to the bottom of the inner rod 2, and a grouting channel 51 communicating with the inner rod grouting channels 4 is provided inside the grouting excavation drill bit 5. When the excavation wing plate 6 is located at the bottom of the inner rod 2, multiple excavation wing plates 6 are arranged circumferentially at intervals on the outer peripheral wall of the grouting excavation drill bit 5. A grouting slit 62 is provided on the outer wall of the grouting pipe 61, and the grout is sprayed out through the grouting slit 62 through the interconnected channels.

[0040] like Figure 1 and Figure 2 As described above, when the excavating wing plate 6 is located at the bottom of the inner rod 2, multiple excavating wing plates 6 are arranged circumferentially at intervals on the outer peripheral wall of the shotcrete excavation drill bit 5; the shotcrete pipe 61 is located at the bottom of the excavating wing plate 6 and is connected to the shotcrete channel 51 of the drill bit; the shotcrete pipe 61 is parallel to the surface of the excavating wing plate 6, and all shotcrete seams 62 rotate around the central axis of the drill bit center rod 502 to spray and cover an area that is the same as the annular area obtained by subtracting the cross section of the drill bit center rod 502 from the cross section of the mixing pile.

[0041] like Figure 14 As shown in (d), when the excavating wing plate 6 is located at the bottom of the outermost mixing wing 3, and the outermost mixing wing 3 is driven by the inner rod 2, multiple excavating wing plates 6 are arranged radially at intervals at the bottom of the outermost mixing wing 3; the grouting pipe 61 is located at the bottom of the excavating wing plate 6, and the grouting pipe 61 is connected to the grouting channel 4 of the inner rod.

[0042] like Figure 3As shown, when the excavating wing plate 6 is located at the bottom of the outermost stirring wing 3, and the outermost stirring wing 3 is driven by the outer rod 1, a plurality of excavating wing plates 6 are arranged in radial intervals at the bottom of the outermost stirring wing 3; the shotcrete pipe 61 is arranged at the bottom of the stirring wing 3 driven by the inner rod 2, and the shotcrete pipe 61 is in communication with the inner rod shotcrete channel 4. By corresponding to different structures of the shotcrete pipe 61, stable shotcreting during stirring can be further achieved, and the stirring uniformity is improved.

[0043] When the excavating wing plate 6 is located at the bottom of the outermost stirring wing 3, and the outermost stirring wing 3 is driven by the inner rod 2, the structure is similar to that of the shotcrete excavating drill bit 5, and a plurality of excavating wing plates 6 are arranged in radial intervals at the bottom of the outermost stirring wing 3; the shotcrete pipe 61 is arranged at the bottom of the excavating wing plate 6, and the shotcrete pipe 61 is in communication with the inner rod shotcrete channel 4.

[0044] The design of the drill bit part and the internal channel of the drill can realize multi-channel shunting under the condition that the amount of solidifying agent slurry required per unit depth is certain, the multiple shotcrete pumps work independently, and then the solidifying agent slurry is uniformly spread on each circumference of the pile section through the shotcrete joint 62, and the multiple circumferential superposition effect covers the entire pile section, so that the solidifying agent is uniformly spread on the entire section of the large-diameter pile. The solidifying agent slurry is no longer concentrated, the back-shooting problem is solved, the solidifying agent content in the soil in each unit depth range is ensured to be consistent, and then the strength difference of the solidified soil at each point is as small as possible. By using this structure, the construction diameter of the mixing pile can reach 1500mm-3000mm, or even larger.

[0045] As shown in Figures 4 to 6 , the shotcrete joint 62 is surrounded by the bottom surface of the excavating wing plate 6 and the notch provided on the shotcrete pipe 61, or the shotcrete joint 62 is formed by the side wall opening of the shotcrete pipe channel 610. In this way, different shotcrete joints are set according to the size of the shotcrete amount, and the structure design of the joint can make the shotcrete joint 62 partially blocked, and the slurry in the unblocked part is washed to the whole joint to be unobstructed, effectively avoiding the problem of shotcrete port blockage. Figure 5 , Figure 9 As shown, the width of the shotcrete joint 62 is determined by the circular area to be covered.

[0046] As shown in Figure 7 , the shotcrete joint 62 is arranged in the shadow area 7 of the shotcrete rotating earth-facing surface of the shotcrete excavating drill bit 5. It can effectively prevent the soil from entering the shotcrete channel and ensure smooth shotcreting. As shown in Figure 7 , the direction of the plate surface of the excavating wing plate 6 and the cross-sectional direction of the drill bit center rod 502 form an angle θ1, and the range of θ1 is 0-45°. It can produce better shear disturbance effect on the soil in front of the plate in the rotation direction, and at the same time, it can reduce the increased resistance of the drill bit.

[0047] As shown in Figure 8 and 9 The outer end of the axial end face of the shotcrete pipe channel 610 inside the shotcrete pipe 61 is provided with a removable rodless shotcrete plug 611 or a rod shotcrete plug 612 according to the position of the opening slot. The setting of the shotcrete plug greatly reduces the difficulty of cleaning the blocked pipe when the shotcrete channel is blocked due to the inability to discharge oversized particles. As shown in Figure 8 The rodless shotcrete plug 611 or the rod shotcrete plug 612 is installed at the end of the excavation wing plate 6 and is provided with a plug thread 6122 matched with the shotcrete pipe thread 621, and the end of the plug is provided with an internal hexagonal hole 6123, which further increases the convenience of disassembling the shotcrete plug. The rod shotcrete plug 612 is used to prevent the curing agent slurry from accumulating in the unslotted area of the shotcrete pipe 61 and forming hardened blockage.

[0048] The application relates to a method for using a drill for large-diameter multi-layer inter-shearing mixing pile construction.

[0049] Before the mixing pile machine starts construction, the slurry supply smoothness of the entire drill is checked. The drill rear end starts to supply the curing material slurry through multiple slurry pumps, each slurry pump corresponds to an inner rod slurry channel 4. The curing material slurry flows through the inner rod slurry channel 4, the drill bit shotcrete channel 51, the shotcrete pipe channel 610, and finally is sprayed out through the shotcrete slot 62. At this time, it indicates that the slurry supply is normal and no blockage occurs in each channel. At the same time, the normality of the opposite rotation of the inner rod and the outer rod driven by the power device is checked. If it is normal, the next step can be performed.

[0050] The drill starts to drill and rotate. Through the action of the excavation wing plate 6, the soil in front of the plate is subjected to upward and forward components, and a certain space cavity is formed behind the plate. At the same time, the shotcrete slot 62 continuously sprays the curing agent slurry, which is uniformly distributed in the cut soil. When the mixing wing 3 connected to the inner rod and the outer rod reaches the position of the soil mixed with the slurry, the soil containing the slurry is further inter-sheared and mixed to be more uniform. When the mixing drill reaches the pile bottom elevation, the pile body has been uniformly mixed with the curing agent slurry, and has been stirred once. Thus, the one-spraying-one-mixing construction is completed.

[0051] Finally, the rear-end slurry delivery is closed, and the drill starts to reverse and lift. The cement-soil pile body is stirred again, and the uniformity is improved again. When the mixing drill is lifted to leave the ground, the one-spraying-two-mixing construction is completed, and the construction is completed. If necessary, the above steps can be repeated once to complete the two-spraying-four-mixing construction. After the construction is completed, the rear-end pump delivers clean water to flush out the residual slurry or residue in the drill rod, the drill bit center rod 502 and the shotcrete channel. If it cannot be flushed out, the shotcrete plug can be disassembled, and the shotcrete channel can be cleaned again to be smooth by using a tool.

[0052] The following will be further illustrated by two embodiments:

[0053] Embodiment one:

[0054] This embodiment is to construct large-diameter mixing piles, and the pile diameter D = 1500 mm. The drill bit center pipe diameter is d = 173 mm, and two grouting pumps are used for simultaneous grouting.

[0055] Specifically, as shown in Figure 1 , the double-layer drill used in this embodiment obtains power through the pin connection of the inner drill rod 200 and the inner rod connecting head 201 and the pin connection of the outer drill rod 100 and the outer rod connecting head 101. The entire drill adopts a double-layer mixing wing 3 structure. The mixing wings 3 rotating with the outer rod 1 are in the shape of "E", and there are three in total, which are radially distributed on the outer surface of the outer rod 1, and the included angle between each two is 120°. The mixing wings 3 rotating with the inner rod 2 are in the shape of a straight plate, which are radially distributed on the outer surface of the inner rod 2, and are arranged in staggered layers, and the horizontal included angle of adjacent layers of mixing wings is 120°. When the inner and outer rods rotate in opposite directions, the mixing wings 3 of the inner and outer rods close to each other shear and disturb the soil. The staggered mixing wings 3 on the inner rod 2 disturb the layer gap area which cannot be contacted by the mixing wings 3 on the outer rod 1, so the soil in this area can be fully mixed.

[0056] In addition, as shown in Figure 2 , the inner drill rod channel 300 in this embodiment is connected with the inner rod grouting channel 4, and at the same time is connected with the drill grouting channel 51 and the grouting pipe channel 610 in the distributed grouting excavation drill bit 5 in sequence, so as to realize the supply and circulation of the curing agent slurry. As shown in Figure 4 , the distributed grouting excavation drill bit 5 is provided with two excavation wing plates 6 and a spiral wing plate 64 arranged at 180°. A plurality of first excavation teeth 63 are arranged on the excavation wing plate 6, and a plurality of second excavation teeth 65 are arranged at the end of the spiral wing plate 64, which is beneficial to the effective excavation of the drill to the deep part of the soil layer, especially to the hard soil layer. As shown in Figure 6 , two grouting pipe groups are respectively arranged in parallel below the excavation wing plate 6 and form a grouting joint 62, and the joint width and joint position are as shown in Figure 5 , Figure 9 (a), Figure 9 (b). The first grouting joint 62-1 of the first grouting pipe 61-1 is opened near the drill bit center rod 502 side, and the joint width is L1. The second grouting joint 62-2 of the second grouting pipe 61-2 is opened away from the drill bit center rod 502 side, and the joint width is L2. Then L1+L2=D-d. When the distributed grouting excavation drill bit 5 rotates continuously, it can cover the entire pile foundation section to achieve the purpose of uniform grouting.

[0057] Before construction, check the activity of the drill mixing wing 3, the digging wing 3 and the patency of each channel. When a certain guniting channel is abnormal, use a hexagonal wrench to unscrew the screw plug, and use other tools to dredge the guniting channel and guniting joint 62 until they are unobstructed, and then restore the screw plug. After the second test guniting is normal, guniting is performed, the guniting is stopped, and the pile is lifted to complete the construction of the pile foundation.

[0058] Example two:

[0059] This example is the construction of a large-diameter mixing pile, with a pile diameter D = 3000 mm. The drill bit center pipe diameter is d = 219 mm, and three grouting pumps are used for simultaneous grouting.

[0060] Specifically, as shown in Figure 1 , the double-layer drill used in this example obtains power through the pin connection of the inner drill rod 200 and the inner rod connector 201 and the flange connection of the outer drill rod 100 and the outer rod connector 101. This example uses a three-layer mixing wing 3 structure as shown in Figure 10 , in which the outermost and innermost mixing wings 3 rotate with the outer rod 1, and there are a total of three in each layer, radially distributed on the outer surface of the outer rod 1, with an included angle of 120° between adjacent two. The middle layer mixing wing 3 rotating with the inner rod 2 is spaced 180° apart on the outer surface of the inner rod 2. When the inner and outer rods rotate in opposite directions, the mixing wings 3 of the inner and outer rods that are relatively close to each other shear and disturb the soil in multiple directions. Due to the arrangement of the three-layer mixing wing and the fact that the rotation trajectories of the mixing wings do not completely overlap, the soil in different areas can be stirred separately and the soil in the same area can be stirred repeatedly, greatly increasing the stirring effect and uniformity and avoiding insufficient stirring and poor effect due to the large diameter of the mixing pile.

[0061] In addition, as shown in Figure 10 , the grout distribution method used in this example is similar to that of example one, except that, as shown in Figure 12 , the distributed guniting and digging drill bit 5 is provided with three digging wing plates 6 and helical wing plates 64 arranged at an angle of 120°. The digging wing plates 6 are provided with a plurality of first digging teeth 63 arranged at intervals, and the end of the helical wing plate 64 is provided with a plurality of second digging teeth 65 arranged at intervals, which facilitates effective digging of the drill into the deep soil layer. Three guniting pipe groups are each arranged in parallel below the digging wing plate 6 and form a guniting joint 62, and the joint width and joint position are as shown in Figure 13 , Figure 9 (a), Figure 9 (b), Figure 9(c) as shown, the first jetting pipe 61-1 has a first jetting slit 62-1 opened near the side of the drill center rod 502, with an opening width of L1, the second jetting pipe 61-2 has a second jetting slit 62-2 opened away from the side of the drill center rod 502, with an opening width of L2, and the third jetting pipe 61-3 has a third jetting slit 62-3 opened at a relatively intermediate position, with an opening width of L3, and L1+L2+L3=D-d. This design can effectively avoid the situation of insufficient grouting pump flow supply due to the too large diameter of the mixing pile and the huge amount of solidifying agent needed to be mixed into the pile body per unit length, without the need to use a super-power grouting pump, and three conventional pumps are used for shunting to control the respective pile body coverage area for spreading slurry, and finally achieve uniform distribution of the entire pile foundation section.

[0062] In summary, the advantages of the present application are that by adopting such a drilling tool mixing structure, the problems of limited mixing area caused by consistent trajectory of the mixing wings 3 and poor shearing effect of the mixing wings 3 on each other are solved, a larger range of soil disturbance can be achieved, the mixing time is consistent compared with the conventional mixing method, but the mixing is more sufficient and uniform, thereby the strength difference of the mixing pile body is greatly reduced and the overall strength is greatly improved, in addition, the drilling tool form can well avoid the problems of co-rotation of the viscous soil wrapping the drill bit and the easy residual soil in the gap area between the inner and outer mixing wings 3 during the bit lifting.

[0063] Although the present disclosure is disclosed as above, the protection scope of the present disclosure is not limited to this. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present disclosure, and these changes and modifications will fall within the protection scope of the present application.

Claims

1. A drilling tool for constructing large-diameter, multi-layer shear-mixing piles, characterized in that, It includes an outer rod (1), an inner rod (2), at least two stirring blades (3), and multiple excavation blades (6); the inner rod (2) is provided with at least one inner rod slurry channel (4); the outer rod (1) is rotatably connected to the inner rod (2); at least one stirring blade (3) is radially distributed on the outer side wall of the central axis of the outer rod (1); at least one stirring blade (3) is radially distributed on the outer side wall of the central axis of the inner rod (2), and the stirring blades (3) on the outer rod (1) are connected to the inner rod (2). The stirring blades (3) on the inner rod (2) are arranged in inner and outer layers and do not interfere with each other when rotating; the stirring blades (3) located in the same layer rotate in the same direction as the outer rod (1) or rotate in the same direction as the inner rod (2). There is at least one fixed connection point between the stirring blade (3) and the rod rotating in the same direction. When the stirring blade (3) is connected to the rod rotating in the opposite direction at the same time, the stirring blade (3) and the rod are rotatably connected; multiple excavation blades (6) are arranged at the bottom of the inner rod (2) or at the bottom of the outermost stirring blade (3); It also includes a shotcrete excavation drill bit (5), which is connected to the bottom of the inner rod (2), and the shotcrete excavation drill bit (5) is provided with a drill bit shotcrete channel (51) that is connected to the inner rod slurry channel (4). It also includes a grouting pipe (61), on the outer wall of which grouting slots (62) are provided; when the excavating wing plate (6) is located at the bottom of the inner rod (2), multiple excavating wing plates (6) are arranged circumferentially at intervals on the outer peripheral wall of the grouting excavation drill bit (5); the grouting pipe (61) is located at the bottom of the excavating wing plate (6), and the grouting pipe (61) is connected to the grouting channel (4) of the inner rod; when the excavating wing plate (6) is located at the bottom of the outermost stirring wing (3), and the outermost stirring wing (3) is driven by the inner rod (2), multiple excavating wing plates (6) are arranged radially at intervals. The outermost stirring blade (3) is located at the bottom; the grouting pipe (61) is located at the bottom of the excavating blade (6), and the grouting pipe (61) is connected to the inner rod grouting channel (4); when the excavating blade (6) is located at the bottom of the outermost stirring blade (3), and the outermost stirring blade (3) is driven by the outer rod (1), multiple excavating blades (6) are arranged radially at intervals at the bottom of the outermost stirring blade (3); the grouting pipe (61) is located at the bottom of the next outermost stirring blade (3) driven by the inner rod (2), and the grouting pipe (61) is connected to the inner rod grouting channel (4); When the stirring blades (3) are distributed in three layers, the following five installation modes are included: First mode: The inner stirring blades (3) are driven to rotate and stir via the inner rod (2); the middle stirring blades (3) are driven to rotate and stir via the outer rod (1); the outer stirring blades (3) are driven to rotate and stir via the inner rod (2); Second mode: The inner stirring blades (3) are driven to rotate and stir via the outer rod (1); the middle stirring blades (3) are driven to rotate and stir via the inner rod (2); the outer stirring blades (3) are driven to rotate and stir via the outer rod (1); Third mode: The inner stirring blades (3) are driven to rotate and stir via the outer rod (1); the middle stirring blades (3) are driven to rotate and stir via the inner rod (2); the middle stirring blades (3) are driven to rotate and stir via the outer rod (1); the outer stirring blades (3) are driven to rotate and stir via the outer rod (1); the inner stirring blades (3) are driven to rotate and stir via the outer rod (1); the middle stirring blades (3) are driven to rotate and stir via the inner rod (2); the outer stirring blades (3) are driven to rotate and stir via the outer rod (1 ... outer rod (1); the outer stirring blades (3) are driven to rotate and stir via the outer rod (1); the outer stirring blades (3) are driven to rotate and stir via the outer The inner rod (2) drives the rotational stirring; the outer stirring blade (3) drives the rotational stirring through the inner rod (2); the fourth mode: the inner stirring blade (3) drives the rotational stirring through the inner rod (2); the middle stirring blade (3) drives the rotational stirring through the inner rod (2); the outer stirring blade (3) drives the rotational stirring through the outer rod (1); the fifth mode: the inner stirring blade (3) is simultaneously set on the inner rod (2) and the outer rod (1), and drives the rotational stirring through the inner rod (2) and the outer rod (1) respectively; the middle stirring blade (3) drives the rotational stirring through the inner rod (2); the outer stirring blade (3) drives the rotational stirring through the outer rod (1).

2. The drilling tool for constructing large-diameter, multi-layer shear mixing piles according to claim 1, characterized in that, The surface direction of the excavating wing plate (6) forms an angle θ with the cross-sectional direction of the shotcrete excavating drill bit (5), where θ ranges from 0 to 45°.

3. The drilling tool for constructing large-diameter, multi-layer shear mixing piles according to claim 1, characterized in that, The area covered by the grouting of all the grouting seams (62) around the central axis of the grouting excavation drill bit (5) is equal to the annular area obtained by subtracting the cross section of the inner rod (2) from the cross section of the mixing pile.

4. The drilling tool for constructing large-diameter, multi-layer shear mixing piles according to claim 1, characterized in that, The grouting seam (62) is located within the shaded area (7) of the grouting rotating face at the bottom of the grouting excavation drill bit (5).

5. The drilling tool for constructing large-diameter, multi-layer shear mixing piles according to claim 1, characterized in that, The outer end face of the shotcrete pipe (61) is detachably connected to a rodless grout stop plug (611) or a grout stop plug with a rod (612).

6. The drilling tool for constructing large-diameter, multi-layer shear mixing piles according to claim 1, characterized in that, When the stirring blade (3) is distributed in two layers, there are two installation modes; the first mode: the inner stirring blade (3) is set on the inner rod (2) and driven to rotate and stir through the inner rod (2); the outer stirring blade (3) is set on the outer rod (1) and driven to rotate and stir through the outer rod (1); the second mode: the inner stirring blade (3) is set on the outer rod (1) and driven to rotate and stir through the outer rod (1); the outer stirring blade (3) is set on the inner rod (2) and driven to rotate and stir through the inner rod (2).

7. The drilling tool for constructing large-diameter, multi-layer shear mixing piles according to claim 1, characterized in that, When the stirring blade (3) is distributed in four layers, it includes the following two installation modes: First mode: the inner stirring blade (3) is driven to rotate and stir through the inner rod (2); the middle inner stirring blade (3) is driven to rotate and stir through the outer rod (1); the middle outer stirring blade (3) is driven to rotate and stir through the inner rod (2); the outer stirring blade (3) is driven to rotate and stir through the outer rod (1); Second mode: the inner stirring blade (3) is driven to rotate and stir through the outer rod (1); the middle inner stirring blade (3) is driven to rotate and stir through the inner rod (2); the middle outer stirring blade (3) is driven to rotate and stir through the outer rod (1); the outer stirring blade (3) is driven to rotate and stir through the inner rod (2).

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