A drilling and injecting integrated screw pile foundation structure

Abstract

The utility model discloses a kind of drilling and injecting integrated spiral pile foundation structures, including pile body, and pile disc, slurry conveying device, load transmission device being set on pile body, load transmission device is set on the outer wall of upper end of pile body, slurry nozzle is provided on pile disc, slurry conveying device is connected with slurry nozzle, slurry nozzle is set along radial direction on the upper end of pile disc, so that slurry ejected from slurry nozzle is ejected into the helical groove of soil body hole wall along the helical path of soil body broken by pile disc, the pile disc helical encircles on the outer wall of pile body, 1≤the spiral number of pile disc<2.The utility model improves the pullout capacity or compression bearing capacity of spiral pile, reduces material and construction cost, and enhances soil density.

Description

Technical Field

[0001] This utility model relates to the field of pile foundation technology, specifically a drilling and grouting integrated spiral pile foundation structure. Background Technology

[0002] Helical pile foundations are an important type of pile foundation, widely used in geotechnical engineering projects such as power transmission and transformation lines, wind power, photovoltaic power generation, and pipeline foundations. To improve the tensile or compressive bearing capacity of the helical piles, multiple pile discs are added to the helical pile foundation. Construction of helical pile foundations requires applying a certain torque and / or pressure to drive the helical piles into the soil. This means that for each additional pile disc, an additional torque is needed to overcome the extra friction between the helical pile foundation and the soil. Therefore, when there are many helical pile discs, it is often difficult to find a matching torque-applying device capable of applying high torque, creating obstacles to the application of helical piles. Furthermore, with a large number of pile discs, the construction of helical pile foundations increases the disturbance area to the soil, reducing soil density and thus, to some extent, decreasing the tensile or compressive bearing capacity of the helical piles.

[0003] Most of the auger drills / auger rigs retrieved by the applicant employ a relatively long pile disc that spirals from one end of the pile body and extends to the other end near the pile disc. The grout outlets for grout output are often located radially outward from the pile disc and along its spiral direction, or directly on the pile body and along its axial direction. For example, the Chinese utility model patent with publication number CN203188200U retrieved by the applicant has grout holes located on the outer wall of the drill rod and distributed along its axial direction.

[0004] When using a auger drill with this type of nozzle, the grout sprayed from the nozzle is applied to the surface of the borehole wall. Under gravity, the grout flows downwards along the borehole wall and covers it. Because of this design, after grouting, the grout cannot penetrate into the interior of each soil layer; it is only sprayed onto the borehole wall surface, reinforcing it and preventing collapse.

[0005] The spiral pile of this utility model is fundamentally different from the spiral drill / spiral drilling machine found by the applicant. The function of the spiral drill is to drill holes, and it is a drilling tool; the function of the spiral pile is to provide load-bearing capacity for the building as a pile foundation.

[0006] To improve the tensile or compressive bearing capacity, traditional helical piles typically increase the number of pile discs or the diameter of the pile discs, which increases the cost of steel. Moreover, the more pile discs there are and the larger the diameter of the pile discs, the more mechanical equipment that can provide greater installation torque is needed, further increasing construction costs. Utility Model Content

[0007] In view of the shortcomings of the existing technology, the purpose of this utility model is to provide an integrated drilling and grouting spiral pile foundation structure, which can solve the problems described in the background technology.

[0008] The technical solution to achieve the purpose of this utility model is as follows: an integrated drilling and grouting spiral pile foundation structure, including a pile body, a pile disc, a grouting device, and a load transfer device disposed on the pile body. The load transfer device is disposed on the outer wall of the upper end of the pile body. A grouting nozzle is disposed on the pile disc. The grouting device is connected to the grouting nozzle. The grouting nozzle is arranged radially at the upper end of the pile disc, so that the grout injected from the grouting nozzle is injected along the spiral path that breaks the soil of the pile disc into the spiral groove of the soil borehole wall. The pile disc spirals around the outer wall of the pile body, where 1 ≤ number of spiral turns of the pile disc < 2.

[0009] Furthermore, the grouting nozzle is located at the radial end edge of the upper end of the pile disk. Multiple grouting nozzles can be provided and distributed radially. One end of the grouting device extends into the pile disk and is connected to the grouting nozzle.

[0010] Furthermore, a slicing head is connected to the radial end edge of the lower end of the pile disk. The thickness of the slicing head gradually decreases along the radial direction away from the pile body, and the thickness of the slicing head gradually increases along the spiral upward direction.

[0011] Furthermore, a fixing ring is connected to the radial end edge of the upper end of the pile disk, which is fixedly or detachably fitted onto the pile disk, and the grouting nozzle extends from the pile disk and is provided on the fixing ring.

[0012] Furthermore, the pile body includes a pile column and a pile tip, the pile tip is fixed to one end of the pile column, the pile disc is spirally wrapped around the pile column, and the end of the pile tip away from the pile column is pointed. The pile column is a column with a cavity. The pile tip is a solid structure or the pile does not have a pile tip. When the pile does not have a pile tip, a baffle is also provided in the cavity of the pile column. The baffle divides the cavity into two parts. One cavity is connected to the pile tip, and the other cavity is isolated from the pile tip and not connected. The grouting device is located in the cavity isolated from the pile tip.

[0013] Furthermore, the cutting head and the pile plate are an integral structure, and the pile tip and the pile column can be an integral structure.

[0014] Furthermore, the grouting device includes a grouting pipe connector, a rotary joint, and a grouting pipe. The grouting pipe connector is inserted into and connected to the rotary joint. The rotary joint is connected to the grouting pipe. One end of the grouting pipe extends into the pile plate and is connected to the grouting nozzle. The rotary joint includes an upper rotary head and a lower rotary head, which are fitted together and rotated, allowing them to rotate relative to each other. The grout delivery pipe is connected to the upper rotary head, and the grout delivery pipe is connected to the lower rotary head.

[0015] Furthermore, the grouting device also includes a first fixing member and a second fixing member. One end of the first fixing member is connected to the rotary joint, and the other end is fixedly connected to the inner wall of the pile cavity. One end of the second fixing member is connected to the grouting pipe, and the other end is fixedly connected to the inner wall of the pile cavity. The second fixing member is located below the first fixing member.

[0016] Furthermore, the first fixing member includes a horizontal bar and a diagonal bar. One end of the horizontal bar is connected to the rotary joint, and the other end of the horizontal bar is fixedly connected to the inner wall of the pile body cavity. One end of the diagonal bar is connected to the horizontal bar, and the other end is fixedly connected to the inner wall of the pile body cavity. The diagonal bar is inclinedly arranged below the horizontal bar.

[0017] Furthermore, the second fixing component includes a connecting rod and a sleeve. The sleeve is fitted onto the grout delivery pipe, one end of the connecting rod is connected to the sleeve, and the other end of the connecting rod is fixedly connected to the inner wall of the pile cavity.

[0018] The beneficial effects of this utility model are: while improving the tensile or compressive bearing capacity of the helical pile, it reduces material and construction costs and enhances soil compaction. Attached Figure Description

[0019] Figures 1-4 Schematic diagrams of the spiral pile foundation structure from different viewing angles; Figure 5 A schematic diagram of the formed helical pile foundation; In the figure, 1-load transfer device, 2-fixing component, 21-horizontal bar, 22-diagonal bar, 3-grouting pipe joint, 4-partition plate, 5-pile body, 51-pile column, 52-pile tip, 6-pile disc, 7-slicing head, 8-grouting nozzle, 9-fixing ring, 10-grouting pipe, 11-connecting rod, 12-sleeve, 13-rotary joint. Detailed Implementation

[0020] The present invention will be further described below with reference to the accompanying drawings and specific embodiments: like Figures 1-5 As shown, a method for constructing an integrated drilling and grouting spiral pile foundation includes the following steps: Step 1: Analyze soil type, density and groundwater level. Based on the analysis results, determine parameters such as the length of the helical pile and the helical pitch of the pile plate 6.

[0021] In this embodiment, the length of the helical pile is represented by the number of helical pile turns, where 1 ≤ number of helical pile turns < 2.

[0022] In this step, the soil type, density, and groundwater level at the target construction site where the helical pile foundation needs to be formed are analyzed to determine the appropriate length and helical pitch of the helical piles to be used. Grouting is then carried out based on these helical piles to obtain the helical pile foundation at the target construction site.

[0023] Step 2: If the helical pile is mainly used for tension resistance, the tail end of the pile plate 6 of the helical pile is inclined upward; if the helical pile is used for compression resistance, the tail end of the pile plate 6 of the helical pile is inclined downward.

[0024] It is understandable that spiral piles generally play two roles during construction: tensile strength and compressive strength. When tensile strength plays a greater role than compressive strength, it can be considered that they are mainly used for tensile strength, and when compressive strength plays a greater role than tensile strength, it can be considered that they are mainly used for compressive strength.

[0025] It is also understandable that, depending on whether the function is to resist tension or compression, pre-set (manufactured) helical piles with upward or downward tilting ends can be selected. Alternatively, the structure can be designed with movable connections, allowing for temporary adjustment of the tail end of the pile disc 6 to be tilted upward or downward according to the site conditions. In other words, the tail end of the pile disc 6 can be movably installed and adjusted to be tilted upward or downward, and different helical piles with upward or downward tilting ends can be manufactured. The appropriate helical pile can be selected based on the usage requirements.

[0026] Step 3: Verify and adjust the pressure and flow parameters of the high-pressure pump, grouting pipe, and spray nozzle 8 to ensure that the pipeline for grout flow is well sealed and prevent blockage, so that the grout can flow normally and be sprayed out from the spray nozzle 8 to complete the grouting operation.

[0027] Step 4: Prepare cement slurry as a slurry according to the preset water-cement ratio, which is usually 1:1-1.5:1.

[0028] Step 5: Use a theodolite, total station, or other equipment to correct the position and verticality of the anchor bolts.

[0029] Step 6: The helical pile is installed at the anchor position and along the verticality. Torque and downward pressure are applied to the helical pile to drive it into the soil. The anchor is only allowed to rotate in one direction, for example, only clockwise. That is, the anchor rotates clockwise throughout the construction process to avoid disturbing the original soil.

[0030] It is understandable that torsional force and downward pressure can be applied to the load transfer device 1 on the helical pile through an external torque application device, thereby applying torque and downward pressure to the helical pile.

[0031] Step 7: After the pile disc 6 on the helical pile is completely inserted into the soil, rotate the helical pile one more turn, that is, rotate the helical pile one revolution, and then start grouting, that is, pour cement grout as grout into the grouting device on the helical pile. The grout is finally sprayed out from the grouting nozzle 8.

[0032] The grouting nozzle 8 is set radially at the upper end of the pile plate 6, so that the grout sprayed from the grouting nozzle 8 can be sprayed along the spiral path of the pile plate 6 breaking the soil into the spiral groove of the soil hole wall. The grout mixes with the soil particles in the soil, and after the grout solidifies, it can form a solidified spiral pile foundation with the soil, thus forming a spiral pile foundation in the spiral groove.

[0033] Compared to traditional helical piles, because the grouting nozzles 8 are arranged radially along the pile disc 6, the grout injected through the nozzles 8 directly enters the groove as the pile disc 6 breaks through the soil wall to form a groove. As the helical pile spirals downwards into the soil, the pile disc 6 forms a spiral groove path, and the grout flows along this path, thus forming the helical pile foundation. This increases the pull-out or compressive bearing capacity of the helical pile foundation. Furthermore, the pile disc 6 does not need to be as long as traditionally arranged along the axial direction of the pile body 5; that is, multiple rings of pile disc 6 are unnecessary, only one ring is required. Of course, in practical use, multiple rings of pile disc 6 are also feasible. Using only one ring of pile disc 6 reduces the number of pile discs 6, thereby reducing soil disturbance and construction costs.

[0034] Step 8: While rotating the helical pile to increase the grouting depth, grouting is carried out. When the helical pile reaches the designed depth, the rotation of the helical pile is stopped and grouting continues until grout overflows, at which point grouting is stopped, thus completing the construction of the helical pile foundation.

[0035] To realize the integrated drilling and grouting spiral pile foundation construction method, this utility model also provides an integrated drilling and grouting spiral pile foundation structure, which can realize the integrated drilling and grouting spiral pile foundation construction method.

[0036] The spiral pile foundation structure includes a pile body 5, a pile plate 6, a grouting device, and a load transfer device 1 installed on the pile body 5. The load transfer device 1 is installed on the outer wall of the upper end of the pile body 5. A grouting nozzle 8 is provided on the pile plate 6. The grouting device is connected to the grouting nozzle 8, so that grout can be injected into the grouting nozzle 8 through the grouting device. The grout is sprayed from the grouting nozzle 8 to the outside to achieve grouting.

[0037] The pile disc 6 is spirally wrapped around the outer wall of the pile body 5. 1 ≤ number of spiral turns of the pile disc 6 < 2, that is, the number of spiral turns of the pile disc 6 is at least 1 turn and cannot exceed 2 turns, so as to minimize the length of the pile disc 6 under the premise of forming a spiral pile foundation structure, thereby avoiding disturbance to the soil and improving the tensile bearing capacity or compressive bearing capacity.

[0038] Understandably, limiting the number of spiral turns of the pile disc 6 to 1-2 turns is intended to avoid excessive turns and the resulting excessive torque required due to an excessive number or length of pile discs 6. Therefore, in practical situations, the number of turns can be appropriately increased, for example, exceeding two turns but limited to 2-3 turns. Setting the number of spiral turns of the pile disc 6 within the range of [1,2) is more suitable.

[0039] The grouting nozzles 8 are located at the radial end edge of the upper end of the pile disk 6. Multiple grouting nozzles 8 can be provided and distributed radially. (Reference) Figure 1 The grouting nozzles 8 are arranged radially away from the pile body 5 at the top of the pile plate 6, that is, they are arranged on the side (not the outer edge) of the top of the pile plate 6, and multiple grouting nozzles 8 are arranged at intervals.

[0040] One end of the grouting device extends into the pile plate 6 and is connected to the grouting nozzle 8.

[0041] like Figure 5 As shown, the grouting nozzle 8 is set at the radial end edge of the upper end of the pile plate 6, so that during the process of the pile body 5 spirally penetrating the soil, the pile plate 6 breaks through the hole wall and forms a strip-shaped groove on the hole wall. The groove is spiral-shaped. The grouting nozzle 8 rotates with the pile plate 6 and moves downward, so that the grouting nozzle 8 moves along the spiral groove. The grout sprayed from the grouting nozzle 8 is sprayed into the groove, thereby forming a spiral pile foundation.

[0042] For example, a cutting head 7 is connected to the radial end edge of the lower end of the pile disc 6. The thickness of the cutting head 7 gradually decreases along the radial direction away from the pile body 5, that is, it is thicker on the inside and thinner on the outside. The thickness of the cutting head 7 gradually increases along the spiral upward direction, that is, the outer edge is thinner. The cutting head 7 is designed in this way to break the soil, thereby forming the groove of the helical pile.

[0043] It is understandable that the slicing head 7 and the pile plate 6 can be an integral structure.

[0044] For example, a fixing ring 9 is also connected to the radial end edge of the upper end of the pile disk 6, which is fixedly and detachably fitted onto the pile disk 6, and the grouting nozzle 8 extends from the pile disk 6 and is disposed on the fixing ring 9.

[0045] For example, the pile body 5 includes a pile column 51 and a pile tip 52. The pile tip 52 is fixed to one end of the pile column 51, and the pile tip 52 and the pile column 51 can be an integral structure. The pile disc 6 is spirally wrapped around the pile column 51. The end of the pile tip 52 away from the pile column 51 is pointed.

[0046] The pile column 51 is a column with a cavity. The pile tip 52 is a solid structure or the pile 5 does not have a pile tip. When the pile 5 does not have a pile tip, a baffle 4 is also provided in the cavity of the pile column 51. The baffle 4 divides the cavity into two parts. One cavity is connected to the pile tip 52, and the other cavity is isolated from the pile tip 52 and not connected. The grouting device is located in the cavity isolated from the pile tip 52, thereby avoiding damage to the grouting device by soil compression during the rotation and sinking of the helical pile.

[0047] For example, the grouting device includes a grouting pipe connector 3, a rotary connector 13, and a grouting pipe 10. The grouting pipe connector 3 is inserted into and connected to the rotary connector 13. The rotary connector 13 is connected to the grouting pipe 10. One end of the grouting pipe 10 extends into the pile disk 6 and is connected to the grouting nozzle 8. The rotary connector 13 includes an upper rotary head and a lower rotary head, which are fitted and rotatably connected, allowing the upper and lower rotary heads to rotate relative to each other. The grouting pipe connector 3 is connected to the upper rotary head, and the grouting pipe 10 is connected to the lower rotary head. The relatively rotatable upper and lower rotary heads ensure that when the pile body 5 rotates into the soil, the grouting pipe 10 and the lower rotary head rotate with the pile body 5, while the upper rotary head remains stationary and rotates relative to the lower rotary head. This prevents the grouting device from becoming twisted, allowing the external grout injection device to connect well with the grouting pipe 10 structure.

[0048] For example, the grouting device further includes a first fixing member 2 and a second fixing member. One end of the first fixing member 2 is connected to the rotary joint 13, and can be connected to the upper or lower rotary head to fix the rotary joint 13. The other end of the first fixing member 2 is fixedly connected to the inner wall of the cavity of the pile body 5. One end of the second fixing member is connected to the grouting pipe 10, and the other end is fixedly connected to the inner wall of the cavity of the pile body 5. The second fixing member is located below the first fixing member.

[0049] For example, the first fixing member 2 includes a horizontal bar 21 and an inclined bar 22. One end of the horizontal bar 21 is connected to the rotary joint 13, and the other end of the horizontal bar 21 is fixedly connected to the inner wall of the cavity of the pile body 5. One end of the inclined bar 22 is connected to the horizontal bar 21, and the other end is fixedly connected to the inner wall of the cavity of the pile body 5. The inclined bar 22 is inclinedly arranged below the horizontal bar, and the inclined bar plays a role in enhancing support.

[0050] For example, the second fastener includes a connecting rod 11 and a sleeve 12. The sleeve 12 is fitted onto the grout delivery pipe 10. One end of the connecting rod 11 is connected to the sleeve 12, and the other end of the connecting rod 11 is fixedly connected to the inner wall of the cavity of the pile body 5.

[0051] The load transfer device 1 is a block structure with multiple load transfer devices 1. Each load transfer device 1 is arranged around the circumference of the pile body 5 at intervals. A notch is provided on one side of the load transfer device 1. The notch facilitates the alignment of the external torque and downward pressure torsion device with the load transfer device 1 during the torsion process, and prevents it from falling off and maintains a stable connection.

[0052] This invention improves the pull-out or compressive bearing capacity of helical piles while reducing material and construction costs and enhancing soil compaction.

[0053] The embodiments disclosed in this specification are merely illustrative of one aspect of the features of this utility model. The protection scope of this utility model is not limited to this embodiment, and any other functionally equivalent embodiments fall within the protection scope of this utility model. Those skilled in the art can make various other corresponding changes and modifications based on the technical solutions and concepts described above, and all such changes and modifications should fall within the protection scope of the claims of this utility model.

Claims

1. A drilled-and-cast-integrated spiral pile foundation structure, characterized in that, The system includes a pile body, a pile disc, a grouting device, and a load transfer device mounted on the pile body. The load transfer device is located on the outer wall of the upper end of the pile body. The pile disc is equipped with grouting nozzles, and the grouting device is connected to the grouting nozzles. The grouting nozzles are arranged radially at the upper end of the pile disc so that the grout injected from the nozzles is injected along a spiral path that breaks through the soil on the pile disc into the spiral grooves on the soil borehole wall. The pile disc spirals around the outer wall of the pile body, where 1 ≤ number of spiral turns of the pile disc < 2.

2. The integrated drilling and grouting helical pile foundation structure according to claim 1, characterized in that, The grouting nozzles are located at the radial end edge of the upper end of the pile disk. Multiple grouting nozzles can be set and distributed radially. One end of the grouting device extends into the pile disk and is connected to the grouting nozzles.

3. The integrated drilling and grouting helical pile foundation structure according to claim 1, characterized in that, The lower end of the pile disk is connected to a slicing head along the radial end edge. The thickness of the slicing head gradually decreases along the radial direction away from the pile body, and the thickness of the slicing head gradually increases along the spiral upward direction.

4. The integrated drilling and grouting helical pile foundation structure according to claim 3, characterized in that, A fixing ring is also connected to the radial end edge of the upper end of the pile disk, which is fixedly or detachably fitted onto the pile disk, and the grouting nozzle extends from the pile disk and is set on the fixing ring.

5. The integrated drilling and grouting helical pile foundation structure according to claim 4, characterized in that, The pile body includes a pile column and a pile tip. The pile tip is fixed to one end of the pile column, and the pile disc spirally wraps around the pile column. The end of the pile tip away from the pile column is pointed. The pile column is a column with a cavity. The pile tip is a solid structure or the pile does not have a pile tip. When the pile does not have a pile tip, a baffle is also provided in the cavity of the pile column. The baffle divides the cavity into two parts. One cavity is connected to the pile tip, and the other cavity is isolated from the pile tip and not connected. The grouting device is located in the cavity isolated from the pile tip.

6. The integrated drilling and grouting helical pile foundation structure according to claim 5, characterized in that, The cutting head and the pile plate are integrated into one structure, and the pile tip and the pile column can be integrated into one structure.

7. The integrated drilling and grouting helical pile foundation structure according to claim 1, characterized in that, The grouting device includes a grouting pipe connector, a rotary joint, and a grouting pipe. The grouting pipe connector is inserted into and connected to the rotary joint. The rotary joint is connected to the grouting pipe. One end of the grouting pipe extends into the pile plate and is connected to the grouting nozzle. The rotary joint includes an upper rotary head and a lower rotary head, which are fitted together and rotated, allowing them to rotate relative to each other. The grout delivery pipe is connected to the upper rotary head, and the grout delivery pipe is connected to the lower rotary head.

8. The integrated drilling and grouting helical pile foundation structure according to claim 7, characterized in that, The grouting device further includes a first fixing member and a second fixing member. One end of the first fixing member is connected to a rotary joint, and the other end is fixedly connected to the inner wall of the pile cavity. One end of the second fixing member is connected to a grouting pipe, and the other end is fixedly connected to the inner wall of the pile cavity. The second fixing member is located below the first fixing member.

9. The integrated drilling and grouting helical pile foundation structure according to claim 8, characterized in that, The first fixing component includes a horizontal bar and an inclined bar. One end of the horizontal bar is connected to the rotary joint, and the other end of the horizontal bar is fixedly connected to the inner wall of the pile body cavity. One end of the inclined bar is connected to the horizontal bar, and the other end is fixedly connected to the inner wall of the pile body cavity. The inclined bar is inclinedly set below the horizontal bar.

10. The integrated drilling and grouting helical pile foundation structure according to claim 8, characterized in that, The second fastener includes a connecting rod and a sleeve. The sleeve is fitted onto the grout delivery pipe. One end of the connecting rod is connected to the sleeve, and the other end of the connecting rod is fixedly connected to the inner wall of the pile cavity.

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