Expanded-base screw pile

Abstract

The utility model relates to the field of foundation reinforcement, and discloses an expanded-base screw pile which comprises an outer pile body, the outer pile body comprises a hollow pipe, the outer side wall of the hollow pipe is provided with a threaded structure, the lower portion of the hollow pipe is connected with a first conical part, and the first conical part is provided with a first grout outlet hole; the core rod body penetrates through the upper end of the hollow pipe and is detachably connected with the interior of the outer pile body. The expanded end similar to a large-diameter expanded-base cast-in-place pile is formed by conducting expanded-base treatment on the bottom of the pile, and the contact area between the pile and a soil body is remarkably increased. By means of the structure, the compression resistance and the pulling resistance of the pile are improved, floating and displacement of the pile body can be effectively prevented, and the stability and the bearing capacity of the pile are greatly improved.

Description

Technical Field

[0001] The utility model relates to the field of foundation reinforcement, in particular to an under-reamed screw pile. Background Art

[0002] In the foundation reinforcement project, the screw pile, as a commonly used reinforcement means, improves the bearing capacity of the soil by forming an anchoring point in the foundation.

[0003] The patent with the publication number CN210737516U discloses a screw pile, which includes an outer pile body and a pile core. Specifically: the outer pile body includes a first pile body made of engineering plastic. The first pile body includes a shell and a thread structure. One end of the shell is open, and the other end forms a conical part. The thread structure is arranged on the outer surface of the shell; the pile core is arranged inside the shell and is anchored to the shell through at least one fastener.

[0004] For the above screw pile, the fastener is anchored to connect the fastener and the shell, so as to fix the pile core and the outer pile body into one body, enabling the effective combination of the outer pile body and the pile core. Rotating the screw pile clockwise can embed it into the soil. The thread structure extending into the soil is in close contact with the soil and is restricted by the soil to form a large up and down resistance. This resistance is transmitted to the pile core through the fastener to converge into a large uplift force, which has a great improvement compared with the traditional gravity concrete foundation.

[0005] Although the traditional screw pile forms up and down resistance by relying on the contact between the thread structure and the soil, and can improve the bearing capacity of the soil to a certain extent, in special geological conditions, such as soft soil or complex strata, its stability and bearing capacity still face challenges.

[0006] In view of this, how to improve the stability and bearing capacity of the traditional screw pile has become a technical problem that needs to be solved urgently by those skilled in the art. Summary of the Utility Model

[0007] The utility model aims to provide an under-reamed screw pile to overcome the defects of poor stability and low bearing capacity of the traditional screw pile.

[0008] In order to achieve the above purpose, the technical solution of the utility model is as follows:

[0009] An under-reamed screw pile, comprising:

[0010] An outer pile body, the outer pile body includes a hollow pipe, a thread structure is arranged on the outer side wall of the hollow pipe, a first conical part is connected below the hollow pipe, and the first conical part is provided with a first slurry outlet hole; and

[0011] A core rod body penetrating through the upper end of the hollow pipe and detachably connected to the inside of the outer pile body.

[0012] Further, the core rod body includes a rod body and a second conical portion. The upper end of the rod body penetrates through the upper end of the hollow tube. The lower end of the rod body is fixedly connected or integrally formed with the second conical portion, and the second conical portion is adapted to the inner side wall of the first conical portion.

[0013] Further, a spiral groove is provided at the lower end of the side wall of the rod body. The spiral groove is in an upward spiral shape. A sliding block adapted to the spiral groove is fixedly connected to the inner side wall of the outer pile body, and the sliding block is slidably connected to the spiral groove.

[0014] Further, insertion grooves are provided on the side wall of the lower end of the rod body and the side wall of the second conical portion. The lower end of the insertion groove is an open structure, and the upper end of the insertion groove communicates with the spiral groove.

[0015] Further, the spiral direction of the spiral groove is the same as the spiral direction of the thread structure.

[0016] Further, a plurality of second slurry outlet holes are arranged at the lower end of the side wall of the hollow tube, and the second slurry outlet holes are located between adjacent teeth of the thread structure.

[0017] Further, a conical protective sleeve is fixedly sleeved on the outer side wall of the first conical portion. Third slurry outlet holes are provided on the conical protective sleeve, and the third slurry outlet holes are arranged opposite to the first slurry outlet holes.

[0018] Further, the thread structure has an equal pitch, and the major diameter of the thread structure gradually increases in the direction away from the first conical portion.

[0019] Further, a first connecting ear is fixedly connected to the upper end of the outer side wall of the rod body. A rectangular frame is fixedly connected to the upper surface of the first connecting ear. A clamping rod passes through the top plate, bottom plate of the rectangular frame and the first connecting ear. A compression spring is arranged in the rectangular frame. The compression spring is sleeved on the middle part of the clamping rod. A sliding plate is slidably connected in the rectangular frame along the vertical direction. The sliding plate is located above the compression spring and is perpendicularly and fixedly connected to the clamping rod. Two ends of the compression spring are respectively connected to the sliding plate and the bottom plate of the rectangular frame. A stop rod is fixedly connected to the lower end of the clamping rod;

[0020] A second connecting ear is fixedly connected to the outer side wall of the upper end of the hollow tube. The second connecting ear is provided with a through hole and a blind groove adapted to the stop rod. The blind groove is arranged on the lower surface of the connecting ear, and the blind groove intersects with the through hole. The stop rod passes through the through hole and is detachably connected to the blind groove.

[0021] Further, an operating rod is perpendicularly and fixedly connected to the upper end of the clamping rod.

[0022] The utility model has at least the following advantages compared with the prior art:

[0023] By loading the core rod body into the outer pile body, the utility model can effectively avoid the deformation of the outer pile body caused by soil pressure during the process of screwing into the soil layer. After the outer pile body is screwed into the soil layer, the core rod body is taken out from the outer pile body, and concrete meeting the design requirements is added into the outer pile body. Subsequently, the core rod body is loaded into the outer pile body again, and the concrete is extruded through the core rod body, so that the concrete enters the surrounding soil layer through the first slurry outlet holes. Then, the core rod body is taken out from the outer pile body, and reinforced concrete is poured inside the outer pile body.

[0024] By carrying out under-reaming treatment at the bottom of the pile to form an enlarged end similar to that of a large-diameter under-reamed cast-in-place pile, the contact area between the pile and the soil is significantly increased. This structure not only improves the compressive and uplift resistance of the pile, but also effectively prevents the floating and displacement of the pile body, greatly enhancing the stability and bearing capacity of the pile.

[0025] In addition, the utility model realizes the integration of drilling and pile forming and pressure grouting, greatly improving the pile forming quality and construction speed. At the same time, this technology effectively avoids problems such as inclination and pile breakage that may occur in the traditional process, ensuring the project quality.

[0026] The application of the under-reamed screw pile in soft soil or complex strata can improve the stability and bearing capacity of the screw pile. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present utility model. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0028] Figure 1 It is a schematic diagram of the overall structure of the under-reamed screw pile of the present utility model;

[0029] Figure 2 It is a sectional view of the under-reamed screw pile of the present utility model;

[0030] Figure 3 It is a schematic diagram of the structure of the core rod body of the present utility model;

[0031] Figure 4 For the present utility model Figure 2 It is a partial enlarged view of area A in the present utility model;

[0032] Figure 5 For the present utility model Figure 3 It is a partial enlarged view of area B in the present utility model;

[0033] Figure 6 This is a partial structural schematic diagram of the outer pile body of the present utility model;

[0034] Figure 7 This is a structural schematic diagram of the conical protective sleeve of the present utility model.

[0035] Reference numerals: 1, outer pile body; 2, core rod body; 3, conical protective sleeve; 101, hollow tube; 102, thread structure; 103, first conical part; 104, first slurry outlet hole; 105, second slurry outlet hole; 106, second connecting ear; 107, through hole; 108, blind groove; 201, rod body; 202, second conical part; 203, spiral groove; 204, insertion groove; 205, first connecting ear; 206, rectangular frame; 207, clamping rod; 208, compression spring; 209, sliding plate; 210, stop rod; 211, operating rod; 301, third slurry outlet hole. Detailed implementation manners

[0036] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present utility model.

[0037] To make the above objects, features, and advantages of the present utility model more obvious and understandable, the present utility model will be further described in detail below in conjunction with the accompanying drawings and specific implementation manners.

[0038] Referring to Figure 1 , the present utility model provides an under-reamed screw pile, including an outer pile body 1 and a core rod body 2. The outer pile body 1 is composed of a hollow tube 101, the outer side wall is provided with a thread structure 102, a first conical part 103 is connected below, and a first slurry outlet hole 104 is provided. The core rod body 2 penetrates through the upper end of the hollow tube 101 and is detachably connected to the inside of the outer pile body 1. The outer pile body 1 is made of a high molecular polypropylene plus glass fiber material, and the core rod body 2 is made of a metal material.

[0039] Referring to Figures 2 - 4 , the core rod body 2 includes a rod body 201 and a second conical part 202. The upper end of the rod body 201 penetrates through the upper end of the hollow tube 101, and the lower end is fixedly connected or integrally formed with the second conical part 202. The second conical part 202 is adapted to the inner side wall of the first conical part 103.

[0040] The lower end of the side wall of the rod body 201 is provided with a spiral groove 203, which is in an upward spiral shape. A sliding block is fixedly connected to the inner side wall of the outer pile body 1, which is adapted to and slidably connected with the spiral groove 203. Insertion grooves 204 are also provided on the lower end of the side wall of the rod body 201 and the side wall of the second conical portion 202, with the lower end open and the upper end communicating with the spiral groove 203. The rod body 201 is placed inside the outer pile body 1 by downward insertion. In a preferred embodiment of the present invention, the spiral direction of the spiral groove 203 is the same as that of the thread structure 102.

[0041] Referring to Figure 7 , a conical protective sleeve 3 is fixedly sleeved on the outer side wall of the first conical portion 103, and a third slurry outlet hole 301 is provided thereon, which is oppositely arranged with the first slurry outlet hole 104. The conical protective sleeve 3 is made of a metal material and is used to displace small gravels to reduce the influence of small gravels in the soil on the screw pile.

[0042] Referring again to Figure 1 , a plurality of second slurry outlet holes 105 are arranged on the lower end of the side wall of the hollow tube 101, between adjacent teeth of the thread structure 102. By providing the second slurry outlet holes 105, the amount of concrete filled around the hollow tube 101 can be increased, thereby increasing the contact area between the hollow tube 101 and the concrete and improving the stability of the screw pile.

[0043] The thread structure 102 has an equal pitch, and the major diameter gradually increases in the direction away from the first conical portion 103, forming the effect of a self-tapping screw and reducing the difficulty of screwing into the soil layer.

[0044] Referring to Figures 5 - 6 , a first connecting ear 205 is fixedly connected to the upper end of the outer side wall of the rod body 201, and a rectangular frame 206 is fixedly connected to the upper surface. A compression spring 208 is arranged inside the rectangular frame 206 and sleeved on the middle part of the clamping rod 207. A sliding plate 209 is slidably connected inside the rectangular frame 206 in the vertical direction. The sliding plate 209 is located above the compression spring 208 and is perpendicularly and fixedly connected to the clamping rod 207. Both ends of the compression spring 208 are respectively connected to the sliding plate 209 and the bottom plate of the rectangular frame 206. The lower end of the clamping rod 207 is fixedly connected to a stop rod 210, and the upper end of the clamping rod 207 is perpendicularly and fixedly connected to an operating rod 211 to facilitate the operation of the clamping rod 207.

[0045] A second connecting ear 106 is fixedly connected to the upper end of the outer side wall of the hollow tube 101. The second connecting ear 106 is provided with a through hole 107, and a blind groove 108 is arranged on the lower surface. The blind groove 108 and the through hole 107 are arranged in a cross manner, and both the blind groove 108 and the through hole 107 are adapted to the stop rod 210. The stop rod 210 can penetrate through the through hole 107 and be detachably connected to the blind groove 108.

[0046] In a specific embodiment of the present utility model, there are two first connecting ears 205 and two second connecting ears 106. The two first connecting ears 205 are located on the same diameter of the rod body 201, and the two second connecting ears 106 are located on the same diameter of the hollow tube 101. The two first connecting ears 205 and the two second connecting ears 106 are arranged in one-to-one correspondence, and the first connecting ear 205 and the second connecting ear 106 are in clearance fit in the vertical direction, so that the stop rod 210 can be disengaged from the through hole 107.

[0047] When the outer pile body 1 and the core rod body 2 are locked, by controlling the operating rod 211 to overcome the elastic force of the compression spring 208 to control the clamping rod 207 to press down, the stop rod 210 penetrates through the through hole 107. At this time, rotate the operating rod 211 so that the stop rod 210 is arranged opposite to the blind groove 108. Then release the operating rod 211, and the clamping rod 207 moves upward under the action of the compression spring 208, and the stop rod 210 is clamped in the blind groove 108, achieving the locking effect of the outer pile body 1 and the core rod body 2. On the contrary, once again, by controlling the operating rod 211 to overcome the elastic force of the compression spring 208 to control the clamping rod 207 to press down, the stop rod 210 is disengaged from the blind groove 108. At this time, rotate the operating rod 211 so that the stop rod 210 is arranged opposite to the through hole 107, release the operating rod 211, and the clamping rod 207 moves upward under the action of the compression spring 208, and the stop rod 210 is located above the through hole 107, thereby releasing the locking effect of the outer pile body 1 and the core rod body 2.

[0048] The working principle of the present utility model:

[0049] First step, install the core rod body 2 inside the outer pile body 1, and achieve the locking of the core rod body 2 and the outer pile body 1 by the cooperation of the stop rod 210 and the blind groove 108.

[0050] Second step, screw the outer pile body 1 into the soil layer by screwing. Since the core rod body 2 is installed inside the outer pile body 1, the structural strength of the outer pile body 1 can be improved, and the outer pile body 1 can be prevented from deforming during the drilling process.

[0051] Third step, release the locking of the core rod body 2 and the outer pile body 1, unscrew and lift the core rod body 2 from the outer pile body 1, load the concrete according to the design requirements inside the outer pile body 1, and then again, by pressing down and then rotating, gradually install the core rod body 2 into the outer pile body 1, so that the concrete gradually flows out from the first slurry outlet hole 104, the second slurry outlet hole 105 and the third slurry outlet hole 301, forming the effect of an under-reamed pile. Since the spiral direction of the spiral groove 203 is the same as that of the thread structure 102, when the core rod body 2 is screwed down, the outer pile body 1 will not be subjected to an upward rotational force, and the effect of preventing the outer pile body 1 from being disengaged from the soil layer can be achieved.

[0052] Step 4: Repeat the upward and downward rotation of the core rod body 2 to ensure that the concrete enters the soil layer around the outer pile body 1.

[0053] Step 5: Remove the core rod body 2 from the outer pile body 1, install a steel reinforcement cage in the outer pile body 1, pour concrete into it, and then carry out curing.

[0054] Step 6: Clean the concrete on the surface of the core rod body 2 for subsequent reuse.

[0055] It should be understood that if the concrete pouring volume is large, in the operations of the first to the fourth steps, the screw pile can be gradually screwed in. That is, when the outer pile body 1 is screwed into a certain depth, a part of the concrete is poured; then the outer pile body 1 is screwed downward again, and the concrete is poured again.

[0056] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by the terms "longitudinal", "transverse", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation to the present utility model.

[0057] The above embodiments are only descriptions of the preferred modes of the present utility model, and do not limit the scope of the present utility model. Without departing from the design spirit of the present utility model, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present utility model shall fall within the protection scope determined by the claims of the present utility model.

Claims

1. A bottom-enlarged screw pile, characterized in that: include: An outer pile body (1), the outer pile body (1) comprising a hollow tube (101), an outer side wall of the hollow tube (101) being provided with a threaded structure (102), a first tapered portion (103) being connected below the hollow tube (101), and the first tapered portion (103) being provided with a first slurry outlet hole (104); and A core rod body (2) passes through the upper end of the hollow tube (101) and is detachably connected to the interior of the outer pile body (1).

2. The bottom-enlarged screw pile according to claim 1, characterized in that: The core rod body (2) comprises a rod body (201) and a second tapered portion (202); the upper end of the rod body (201) passes through the upper end of the hollow tube (101); the lower end of the rod body (201) and the second tapered portion (202) are fixedly connected or integrally formed; and the second tapered portion (202) is adapted to the inner side wall of the first tapered portion (103).

3. The bottom-enlarged screw pile according to claim 2, characterized in that: A spiral groove (203) is provided at the lower end of the side wall of the rod body (201), and the spiral groove (203) is in an upward spiral shape. A sliding block adapted to the spiral groove (203) is fixedly connected to the inner side wall of the outer pile body (1), and the sliding block is slidably connected to the spiral groove (203).

4. The bottom-enlarged screw pile according to claim 3, characterized in that: An insertion groove (204) is provided on the lower end of the side wall of the rod body (201) and the side wall of the second conical portion (202); the lower end of the insertion groove (204) is an open structure, and the upper end of the insertion groove (204) is connected to the spiral groove (203).

5. The bottom-enlarged screw pile according to claim 3, characterized in that: The rotation direction of the spiral groove (203) is the same as the rotation direction of the thread structure (102).

6. The bottom-enlarged screw pile according to claim 1, characterized in that: A plurality of second slurry outlet holes (105) are arranged at the lower end of the side wall of the hollow tube (101), and the second slurry outlet holes (105) are located between two adjacent teeth of the threaded structure (102).

7. The bottom-enlarged screw pile according to claim 1, characterized in that: The outer wall fixed sleeve of the first conical portion (103) is provided with a conical protective sleeve (3), and the conical protective sleeve (3) is provided with a third pulp outlet hole (301), and the third pulp outlet hole (301) is arranged opposite to the first pulp outlet hole (104).

8. The bottom-enlarged screw pile according to claim 1, characterized in that: The thread structure (102) has a constant pitch, and the major diameter of the thread structure (102) gradually increases in a direction away from the first tapered portion (103).

9. The bottom-enlarged screw pile according to claim 2, characterized in that: The upper end of the outer wall of the rod body (201) is fixedly connected with a first connecting ear (205), the upper surface of the first connecting ear (205) is fixedly connected with a rectangular frame (206), the top plate, the bottom plate and the first connecting ear (205) of the rectangular frame (206) are connected with a clamping rod (207) through and through, a compression spring (208) is arranged in the rectangular frame (206), the compression spring (208) is sleeved in the middle of the clamping rod (207), a slide plate (209) is slidably connected in the rectangular frame (206) along the vertical direction, the slide plate (209) is located above the compression spring (208) and is vertically fixedly connected to the clamping rod (207), the two ends of the compression spring (208) are respectively connected to the slide plate (209) and the bottom plate of the rectangular frame (206), and the lower end of the clamping rod (207) is fixedly connected with a stop rod (210); A second connecting ear (106) is fixedly connected to the outer wall of the upper end of the hollow tube (101), and the second connecting ear (106) is provided with a through hole (107) and a blind groove (108) adapted to the stopping rod (210), and the blind groove (108) is arranged on the lower surface of the connecting ear, and the blind groove (108) and the through hole (107) are cross-arranged, and the stopping rod (210) passes through the through hole (107) and is detachably connected to the blind groove (108).

10. The bottom-enlarged screw pile according to claim 9, characterized in that: The upper end of the clamping rod (207) is vertically fixedly connected to an operating rod (211).

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