A local reaming device for a pile foundation

Abstract

The utility model provides a kind of local chambering device for pile foundation, including drill rod, connecting flange, submersible drill drill bit, drill ring, multiple drilling components, multiple chambering components and multiple support structures;Drill ring is sleeved in the outside of drill rod, and drill rod top is equipped with connecting flange, bottom is equipped with submersible drill drill bit;Multiple support structures are arranged between drill ring and drill rod and are fixedly connected with two;Multiple drilling components are evenly arranged in circumference, and the top of drilling component is respectively connected with drill ring and drill rod.The local chambering device for pile foundation disclosed in the utility model solves the problem that the chambering mode in the related art is significantly affected by formation conditions, the chambering process is difficult to control accurately, resulting in unstable chambering form, difficult to ensure construction quality, and low hole-forming efficiency.

Description

Technical Field

[0001] This utility model belongs to the field of pile foundation technology, and in particular relates to a local hole enlargement device for pile foundations. Background Technology

[0002] Submersible drilling bored piles are a pile foundation construction technology specifically designed for underwater or high-water-level strata construction environments. The basic principle is to directly complete the drilling operation underwater using a submersible drilling rig, followed by concrete pouring to form a monolithic pile body. This technology offers the advantage of flexible adjustment of pile diameter and length, strong adaptability, and can be widely applied to high-rise building foundations, large factory foundation treatment, bridge pile foundation construction, hydraulic engineering foundation reinforcement, and pile foundation construction in special geological environments. By adjusting the drilling depth and pile diameter, this type of pile can meet the load-bearing requirements of various construction conditions.

[0003] However, in some engineering scenarios with high requirements for single pile bearing capacity and resistance to horizontal thrust, the bearing capacity of conventional submersible drilled piles has a bottleneck, making it difficult to effectively meet the structural stress requirements. Therefore, it is often necessary to enlarge the hole at the pile bottom or locally in the pile body to increase frictional resistance and end resistance, thereby improving the overall bearing performance. Currently, the commonly used hole enlargement techniques in engineering, such as high-pressure jet grouting with enlarged heads or jackknobs, are prone to causing hole distortion and inaccurate contours when constructing in hard soil layers or gravel layers due to the high strength and complex particle structure of the strata, making it difficult to meet design requirements. In loose strata such as silt and silty clay, the poor self-stabilizing ability of the soil leads to a high risk of hole collapse. Even with strict control of parameters such as mud density and viscosity, it is difficult to stabilize the hole wall, resulting in the inability to effectively guarantee the quality of hole enlargement. Because the hole enlargement methods in related technologies are significantly affected by strata conditions, the hole enlargement process is difficult to control precisely, resulting in unstable hole enlargement shape, difficulty in guaranteeing construction quality, and low hole formation efficiency, making it difficult to meet the construction needs of high-bearing pile foundations under complex geological conditions. Utility Model Content

[0004] In view of this, the present invention aims to at least partially solve one of the related technical problems.

[0005] To achieve the above objectives, the technical solution of this utility model is implemented as follows:

[0006] A partial hole enlargement device for pile foundations includes a drill rod, a connecting flange, a submersible drill bit, a drill ring, multiple drilling assemblies, multiple hole enlargement assemblies, and multiple support structures.

[0007] The drill ring is fitted onto the outside of the drill rod, the drill rod has the connecting flange at the top and the submersible drill bit at the bottom;

[0008] The plurality of support structures are disposed between the drill ring and the drill rod and are fixedly connected to the drill rod;

[0009] The plurality of drilling components are evenly arranged around the circumference, and the top of each drilling component is connected to the drill ring and the drill rod, respectively.

[0010] The plurality of reaming assemblies are mounted on the drill ring;

[0011] The hole-expanding assembly includes a rotating rod, a bushing, a turntable, an unfolding and returning mechanism that can pivot about an axis, and a limiting rod for limiting the pivoting angle of the unfolding and returning mechanism.

[0012] The lower part of the rotating rod is rotatably engaged with the bushing, the bushing is fixed to the inner wall of the drill ring, the top of the rotating rod is fixedly connected to the turntable, and a limiting nut is provided at the bottom of the rotating rod;

[0013] The unfolding and returning mechanism is mounted on the turntable, and it unfolds radially under the action of slurry resistance when the drill rod rotates in the opposite direction, and returns radially when the drill rod rotates in the forward direction. The limiting rod is mounted on the turntable.

[0014] Furthermore, the inner wall of the drill ring is provided with thickened pads at the corresponding positions where it impacts the limiting rod.

[0015] Furthermore, the hole-enlarging assembly consists of three groups, evenly spaced along the circumference of the drill ring.

[0016] Furthermore, the drilling assembly consists of three groups, evenly spaced along the circumference of the drill ring, with the top of each drilling assembly connected to the drill ring and the bottom connected to the drill rod.

[0017] Furthermore, the unfolding and returning mechanism includes a blade assembly and a paddle assembly, which are symmetrically arranged about the radial center line of the turntable and together form an arc-shaped outline.

[0018] Furthermore, the blade assembly includes a first arc-shaped plate and a rotating blade, one end of the first arc-shaped plate is welded to the turntable, and the rotating blade is disposed on the inner end face of the first arc-shaped plate.

[0019] Furthermore, the cutting tooth assembly includes a second arc-shaped plate and a hole-expanding cutting tooth, with one end of the second arc-shaped plate welded to the turntable and the other end welded to the hole-expanding cutting tooth.

[0020] Furthermore, the support structure includes a support rod and two ribs. One end of the support rod is welded to the drill ring, and the other end is welded to the drill rod. The two ribs are symmetrically arranged, with their outer ends welded to the drill ring and their inner ends welded to the drill rod.

[0021] Furthermore, the outer wall of the drill ring is provided with multiple auxiliary cutting teeth along the circumference.

[0022] Furthermore, the drilling assembly includes drilling blades and multiple drilling teeth. The drilling blades are inclined, the top of the drilling blades is welded to the drill ring, the bottom of the drilling blades is welded to the drill rod, and the multiple drilling teeth are evenly arranged on the drilling blades.

[0023] Compared with existing technologies, the local hole-enlarging device for pile foundations described in this utility model has the following advantages:

[0024] 1. The expansion and return mechanism is centrally located on the turntable, and the pivot angle is stably constrained by the rigid cooperation of the limit rod and the thickened pad, so that the entry angle and radial displacement of the reaming cutter teeth after expansion are in a repeatable controllable state. Under the mechanism of expansion by reverse rotation combined with mud resistance and return by forward rotation, the expansion and retraction do not require additional hydraulic cylinders, seals and pipeline systems, which significantly improves the reliability in underwater and mud environments. The reduction in the number of mechanism components leads to a reduction in failure modes. By controlling the expansion and return of the expansion and return mechanism by forward / reverse rotation, the expansion action is triggered only when the target depth is reached. Thus, the expansion position can be flexibly set at the pile bottom, pile body or pile top / pile end as needed to achieve "partial expansion".

[0025] 2. Because the pre-cutting auxiliary cutting teeth and the inclined drilling blades have disturbed and reduced the load on the hole wall before hole enlargement, the peak torque of the hole enlargement cutting teeth in the initial cutting stage is effectively suppressed, the energy consumption and mechanical impact of the equipment are reduced, and the angle limit further reduces the number of times the operator relies on experience to forcibly repair the hole; the impact part of the limit rod is equipped with a thickened pad, so the repeatability of the hole enlargement angle can be maintained for a long time. Attached Figure Description

[0026] The accompanying drawings, which form part of this utility model, are used to provide a further understanding of the utility model. The illustrative embodiments of the utility model and their descriptions are used to explain the utility model and do not constitute an undue limitation of the utility model. In the drawings:

[0027] Figure 1 This is a schematic diagram of a partial hole enlargement device for pile foundations according to an embodiment of the present utility model;

[0028] Figure 2 This is a schematic diagram of the hole-enlarging assembly described in an embodiment of the present utility model;

[0029] Figure 3 This is a schematic diagram of the blade assembly and the blade assembly described in an embodiment of the present utility model;

[0030] Figure 4 This is a schematic diagram of the support structure described in an embodiment of the present utility model;

[0031] Figure 5 This is a schematic diagram of the drilling assembly described in an embodiment of the present utility model.

[0032] Explanation of reference numerals in the attached figures:

[0033] 110. Connecting flange; 120. Drill rod; 130. Submersible drill bit; 200. Drill ring; 210. Auxiliary cutting teeth; 300. Reaming assembly; 310. Bushing; 320. Rotary rod; 330. Turntable; 340. Blade assembly; 341. First arc plate; 342. Rotating blade; 350. Cutting tooth assembly; 351. Second arc plate; 352. Reaming cutting teeth; 360. Thickened pad; 370. Limiting rod; 400. Support structure; 410. Support rod; 420. Rib plate; 500. Drilling assembly; 510. Drill blade; 520. Drilling cutting teeth. Detailed Implementation

[0034] It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments of the present invention can be combined with each other.

[0035] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0036] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0037] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0038] A partial hole reaming device for pile foundations includes a drill rod 120, a connecting flange 110, a submersible drill bit 130, a drill ring 200, multiple drilling assemblies 500, multiple hole reaming assemblies 300, and multiple support structures 400. The drill ring 200 is sleeved on the outside of the drill rod 120. The top of the drill rod 120 is detachably connected to the upper transmission system via the connecting flange 110. The bottom of the drill rod 120 is equipped with a submersible drill bit 130 to complete the conventional drilling cutting and slag removal process. The outer wall of the drill ring 200 is provided with multiple auxiliary cutting teeth 210 along the circumference to pre-cut and disturb the hole wall and sediment before and after hole reaming to improve cutting stability and mud carrying capacity.

[0039] A support structure 400 is disposed between the drill ring 200 and the drill rod 120 and fixes them together. The support structure 400 includes a support rod 410 and two ribs 420. One end of the support rod 410 is welded to the drill ring 200 and the other end is welded to the drill rod 120. The two ribs 420 are symmetrically arranged about the axis of the support rod 410. Their outer ends are welded to the drill ring 200 and their inner ends are welded to the drill rod 120, thereby providing stiffening support for the drill ring 200 in the circumferential and radial directions and ensuring the coaxiality of the drill ring 200 relative to the drill rod 120, thus maintaining good contour control and torque transmission during the reciprocating hole reaming process.

[0040] The drilling assembly 500 is evenly arranged in three groups along the outer circumference of the drill ring 200. The drilling assembly 500 includes drilling blades 510 and multiple drilling cutter teeth 520. The drilling blades 510 are arranged at an angle relative to the axis of the drill rod 120 to form a spiral-guided cutting and slag removal channel. The top of the drilling blades 510 is welded to the drill ring 200 and the bottom is welded to the drill rod 120. The multiple drilling cutter teeth 520 are evenly arranged along the length of the drilling blades 510. They are used to work with the auxiliary cutter teeth 210 to simultaneously break up weak interlayers and disturb slag during the conventional drilling stage, so as to ensure the stability of the hole formation and the cleanliness of the bottom of the hole before hole enlargement.

[0041] The reaming assembly 300 is mounted on the drill ring 200 and arranged in three groups evenly spaced along the circumference. Each reaming assembly 300 includes a rotating rod 320, a bushing 310, a turntable 330, an unfolding and returning mechanism that can pivot about an axis, and a limiting rod 370 for limiting the pivoting angle of the unfolding and returning mechanism. The lower part of the rotating rod 320 is rotatably engaged with the bushing 310 to form a reliable pivoting support. The bushing 310 is fixed to the inner wall of the drill ring 200 and preferably uses full penetration welding or bevel welding to ensure structural strength under reciprocating impact conditions. The top of the rotating rod 320 is fixedly connected to the turntable 330 to serve as the mounting and load-bearing base for the unfolding and returning mechanism. The bottom of the rotating rod 320 is provided with a limiting nut to lock the rotating rod 320 axially and prevent pivoting. The gap accumulates axially. The expansion and retraction mechanism is set on the turntable 330 and expands radially under the action of mud resistance when the drill rod 120 rotates in the opposite direction. It retracts radially when the drill rod 120 rotates in the forward direction, thus achieving reliable switching between expansion and retraction without the need for an independent hydraulic or electric drive unit. The limiting rod 370 is set on the turntable 330. The inner wall of the drill ring 200 is provided with a thickened pad 360 at the corresponding position where it impacts the limiting rod 370. This is to withstand repeated impacts during the limiting process and stably limit the pivot angle of the expansion and retraction mechanism, so that the entry angle of the reaming tool in different formations is kept within a predetermined range. Preferably, the thickness of the thickened pad 360 is greater than the thickness of the drill ring 200 body and is made of wear-resistant material or has a wear-resistant layer welded on to improve its service life.

[0042] In a preferred embodiment, the unfolding and repositioning mechanism includes a blade assembly 340 and a cutter tooth assembly 350, which are symmetrically arranged about the radial centerline of the turntable 330 and together form an arc-shaped outer contour that matches the outer diameter of the drill ring 200 in the retracted state, so as to ensure that the reaming mechanism does not increase the outer diameter envelope during conventional drilling; wherein, the blade assembly 340 includes a first arc-shaped plate 341 and a rotating blade 342, one end of the first arc-shaped plate 341 is welded to the turntable 330, and the rotating blade 342 is arranged on the inner end face of the first arc-shaped plate 341 to fully withstand the mud flow. The resistance is converted into a torque that propels the unfolding action; the cutting tooth assembly 350 includes a second arc plate 351 and a reaming cutting tooth 352. One end of the second arc plate 351 is welded to the turntable 330 and the other end is welded to the reaming cutting tooth 352. The reaming cutting tooth 352 is preferably made of alloy steel and can be hard-faced or carburized / nitrided in the cutting edge area to improve its wear resistance and anti-chipping ability in abrasive strata such as sandy, gravelly and weakly weathered rock. At the same time, by optimizing the rake angle and the transition radius of the side cutting edge, the torque fluctuation is small and the chip shape is stable when it is extended and cut inward.

[0043] To improve long-term reliability, the bushing 310 and the rotating rod 320 are preferably fitted with wear-resistant bushings or surface-hardened materials, and a clearance control structure to prevent mud penetration is provided in the axial direction to reduce the increase in the fit clearance caused by abrasive particles. The turntable 330 can be made of integral forging or CNC-cut thick plate and then machined to ensure flatness and concentricity. The relative position of the limiting rod 370 and the thickened pad 360 is pre-positioned by tooling and the angle is checked after welding to ensure that the pivot angle of each group of hole-expanding components 300 is consistent when unfolded.

[0044] By controlling the unfolding and retraction of the unfolding and retraction mechanism through forward / reverse rotation, the hole enlargement action is triggered only when the target depth is reached. This allows the hole enlargement position to be flexibly set at the pile bottom, pile body, or pile top / end as needed, achieving "partial hole enlargement".

[0045] How this example works

[0046] Step 1: Start the submersible drill bit 130 and perform conventional drilling under mud wall protection conditions. Control the mud level in the hole to maintain a predetermined freeboard relative to the groundwater level to stabilize the soil pressure on the hole wall. The drill rod 120 maintains positive rotation so that the unfolding and returning mechanism is in a closed state under the action of mud resistance and its own gravity / elastic recovery. The drill blade 510 and drill cutting teeth 520 work together with the auxiliary cutting teeth 210 to complete continuous cutting and disturbance and achieve stable slag removal. Based on the formation feedback, gradually drill to the designed reaming starting depth.

[0047] Step 2: After the drill bit reaches the predetermined reaming position, the control platform switches the drill rod 120 to reverse rotation. The mud resistance obtained by the rotating blade 342 is converted into a spreading torque, driving the blade assembly 340 and the cutter tooth assembly 350 to pivot outward around the rotating rod 320. The rotation is limited to the preset pivot angle range by the cooperation of the limiting rod 370 and the thickened pad 360. Thus, the reaming cutter tooth 352 performs rotary cutting and reaming on the hole wall, and gradually reaches the target hole diameter in the reciprocating reverse-forward rotation rhythm. After the reaming is completed, the drill rod 120 resumes forward rotation. The mud resistance causes the spreading return mechanism to automatically retract to the closed state. Then, hole cleaning and subsequent processes are performed as needed.

[0048] The above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A local hole-enlarging device for pile foundations, characterized in that: It includes a drill rod (120), a connecting flange (110), a submersible drill bit (130), a drill ring (200), multiple drilling assemblies (500), multiple reaming assemblies (300), and multiple support structures (400); The drill ring (200) is sleeved on the outside of the drill rod (120), the drill rod (120) is provided with the connecting flange (110) at the top and the submersible drill bit (130) at the bottom; The plurality of support structures (400) are disposed between the drill ring (200) and the drill rod (120) and are fixedly connected to each other; The plurality of drilling assemblies (500) are evenly arranged around the circumference, and the top of each drilling assembly (500) is connected to the drill ring (200) and the drill rod (120) respectively. The plurality of reaming assemblies (300) are mounted on the drill ring (200); The hole-expanding assembly (300) includes a rotating rod (320), a bushing (310), a turntable (330), an unfolding and returning mechanism that can pivot about an axis, and a limiting rod (370) for limiting the pivoting angle of the unfolding and returning mechanism: The lower part of the rotating rod (320) is rotatably engaged with the bushing (310), the bushing (310) is fixed to the inner wall of the drill ring (200), the top of the rotating rod (320) is fixedly connected to the turntable (330), and a limiting nut is provided at the bottom of the rotating rod (320). The unfolding and returning mechanism is set on the turntable (330), and unfolds radially under the action of the drill rod (120) rotating in the opposite direction and in conjunction with the slurry resistance, and returns radially when the drill rod (120) rotates in the forward direction. The limiting rod (370) is set on the turntable (330).

2. The local hole-enlarging device for pile foundations according to claim 1, characterized in that: The inner wall of the drill ring (200) is provided with a thickened pad (360) at the corresponding position where it impacts the limiting rod (370).

3. A local hole-enlarging device for pile foundations according to claim 1, characterized in that: The hole-reaming assembly (300) consists of three groups, which are evenly spaced along the circumference of the drill ring (200).

4. A local hole-enlarging device for pile foundations according to claim 1, characterized in that: The drilling assembly (500) consists of three groups, which are evenly spaced along the circumference of the drill ring (200), and the top of each drilling assembly (500) is connected to the drill ring (200), and the bottom is connected to the drill rod (120).

5. A partial hole-enlarging device for pile foundations according to any one of claims 1-4, characterized in that: The unfolding and returning mechanism includes a blade assembly (350) and a blade assembly (340), which are symmetrically arranged about the radial center line of the turntable (330) and together form an arc-shaped outline.

6. A local hole-enlarging device for pile foundations according to claim 5, characterized in that: The blade assembly (340) includes a first arc plate (341) and a rotating blade (342). One end of the first arc plate (341) is welded to the turntable (330), and the rotating blade (342) is disposed on the inner end face of the first arc plate (341).

7. A local hole-enlarging device for pile foundations according to claim 5, characterized in that: The cutting tooth assembly (350) includes a second arc-shaped plate (351) and a hole-expanding cutting tooth (352). One end of the second arc-shaped plate (351) is welded to the turntable (330), and the other end is welded to the hole-expanding cutting tooth (352).

8. A local hole-enlarging device for pile foundations according to claim 5, characterized in that: The support structure (400) includes a support rod (410) and two ribs (420). One end of the support rod (410) is welded to the drill ring (200) and the other end is welded to the drill rod (120). The two ribs (420) are symmetrically arranged, with their outer ends welded to the drill ring (200) and their inner ends welded to the drill rod (120).

9. A local hole-enlarging device for pile foundations according to claim 5, characterized in that: The outer wall of the drill ring (200) is provided with a plurality of auxiliary cutting teeth (210) along the circumference.

10. A local hole-enlarging device for pile foundations according to claim 5, characterized in that: The drilling assembly (500) includes a drilling blade (510) and a plurality of drilling teeth (520). The drilling blade (510) is inclined, the top of the drilling blade (510) is welded to the drill ring (200), the bottom of the drilling blade (510) is welded to the drill rod (120), and the plurality of drilling teeth (520) are evenly arranged on the drilling blade (510).

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