A weak foundation cast-in-place pile reinforcement cage placement device and a construction method thereof

Abstract

The application discloses a weak ground bored pile steel reinforcement cage installation device, which comprises a steel winding drum casing, a worm wheel and rack lifting mechanism is installed on the outer side of the steel winding drum casing; a steel reinforcement cage support rod control mechanism is installed on the inner side of the steel winding drum casing, the driving device and the driven device of the steel reinforcement cage support rod control mechanism are connected through stainless steel sheets; a steel reinforcement cage support bracket guiding mechanism and a cam jacking mechanism are installed on the inner side of the steel winding drum casing, and a self-locking mechanism is arranged in the cam jacking mechanism. The construction hole of the weak ground bored pile is easy to collapse, the device takes the steel winding drum as the core, the steel reinforcement cage guiding and fixing device is arranged on the inner side of the steel winding drum, a numerical control power assembly is installed on the upper portion of the steel winding drum, the horizontal, vertical and elevation positioning, guiding, installation and fixing functions of the steel reinforcement cage of the weak ground bored pile are realized, the construction quality of the bored pile is improved, and the overall construction period of the project is improved.

Description

Technical Field

[0001] This invention relates to the technical field of installation devices for reinforcing cages of cast-in-place piles on soft foundations, specifically to an installation device for reinforcing cages of cast-in-place piles on soft foundations and its construction method. Background Technology

[0002] Mud-wall bored piles are a commonly used pile-forming method in China, with a wide range of applications. They can be used in various geological conditions, and for various hole diameters and depths. Quality control during construction mainly includes hole opening, drilling, hole cleaning, reinforcement cage placement, bottom cleaning, and concrete pouring. During the lowering process, the reinforcement cage is easily bumped against the mud wall due to rough handling by workers, especially in poor soil layers such as deep silt. The hole wall is easily disturbed and collapses. In addition, the traditional methods for positioning the horizontal, vertical, and elevation of the reinforcement cage have low accuracy, which affects the pile quality and construction cycle of mud-wall bored piles.

[0003] Application number CN118187056A discloses a casing device for cast-in-place piles, a cast-in-place pile, and a construction method. The casing device includes multiple casing units, multiple connecting rings, and limiting springs. Each casing unit comprises three or more arc-shaped plates connected end-to-end around the axis of the casing unit to form a cylindrical body. Limiting springs are installed and secured to the inner sides of the arc-shaped plates to maintain their cylindrical shape. When the limiting springs detach from the inner sides of the arc-shaped plates, the plates can be radially misaligned and separated. The casing unit designed in this invention includes multiple circumferentially distributed arc-shaped plates forming a cylinder. Connecting rings are installed at both ends, and limiting springs are installed on the inner sides. This design allows the casing unit to be stably inserted into the soil. After drilling, the limiting springs can be released from the inner sides to release the arc-shaped plates, allowing them to move inwards and detach from the soil, making them easier to pull out.

[0004] The device has several drawbacks. When the concrete is poured and the limiting spring and connecting rope are in place inside the casing, the electric gripper cannot function properly, thus hindering quick extraction. Furthermore, there are no quality assurance measures for the installation of the reinforcing cage. When the casing is pulled out, the large contact area between the casing and the soil and concrete results in high friction, making extraction difficult. Additionally, if the casing is tilted, it can damage the soil and the pile.

[0005] Application number CN115928742B discloses a hoisting device for preventing the deformation of reinforcing cages used in drilling and grouting pile construction with mud wall support. It includes a moving platform connected to guide rails via an L-shaped bracket and a first rotating shaft. The guide rails are equipped with a tilting mechanism for securing the reinforcing cage. A top plate is equipped with a clamping mechanism for fastening the traction rope. A second fixing block is equipped with a first adjusting mechanism for controlling the distance between symmetrical first limiting blocks. A T-shaped load-bearing rail is equipped with a second adjusting mechanism for controlling the distance between the first limiting blocks and the top plate. By radially limiting the reinforcing cage at multiple points, local deformation of the reinforcing cage due to uneven force during tilting is avoided. Positioning rollers radially limit the reinforcing cage to prevent collisions with the borehole wall during hoisting. The support mechanism axially and radially limits the reinforcing cage to prevent displacement and collisions with the borehole wall.

[0006] This device has high requirements for site flatness. While lifting the steel cage vertically to the ground, the central axis of the steel cage and the central axis of the casing must be aligned in a straight line, requiring high precision. Furthermore, there are no steel cage fixing measures during concrete pouring. It is necessary to overcome the problems of bending deformation of the steel cage caused by the horizontal component of the lifting point, which affects the pile strength and renders the steel cage unusable when it is severely bent. It is also necessary to overcome the disadvantages of the steel cage and the borehole being difficult to be concentric, which in severe cases causes the steel cage to collide with the borehole wall, resulting in deformation and loss of function. Additionally, when connecting multiple steel cage sections, uneven distribution of support points can cause the steel cage to deflect, making the connection process impossible.

[0007] The application for a borehole pile reinforcement cage locator includes a positioning ring, a positioning cylinder on the positioning ring, and a positioning rod penetrating the positioning cylinder. The positioning rod moves radially along the positioning ring, and a clamping component at the end of the positioning rod is used to clamp the reinforcement cage. An air bladder is provided on the outer circumference of the positioning ring, which, when inflated, can abut against the inner wall of the casing. A telescopic bladder communicating with the air bladder is provided inside the positioning cylinder, which, when inflated, can drive the positioning rod to move. The borehole construction method for bridge construction involved in this application includes several steps: pile location layout, casing installation, mud preparation, drilling, hole inspection and cleaning, reinforcement cage installation, installation of the borehole pile reinforcement cage locator, and concrete pouring. The borehole pile reinforcement cage locator involved in this application improves the ease of positioning work.

[0008] The verticality of the reinforcing cage in this device is greatly affected by the verticality of the casing. The reinforcing cage is fixed by generating friction by inflating the airbag against the inner wall of the casing. For cages with large diameter, long length, and heavy overall weight, the reinforcing cage may slip, leading to defects in the quality of the cast-in-place pile. It is necessary to solve the problem that the limiting reinforcing bars of the drilled cast-in-place pile cannot properly abut against the inner wall of the casing or the borehole, thus requiring multiple corrections of the limiting reinforcing bars, which makes the positioning work inconvenient.

[0009] This invention enables segmented installation of reinforcing cages and precise control over their horizontality, verticality, and elevation, thereby improving the construction quality of cast-in-place piles, extending the overall project duration, and effectively solving the aforementioned problems.

[0010] Therefore, we propose a reinforcement cage placement device and construction method for cast-in-place piles in soft soil foundations to solve the problems mentioned above. Summary of the Invention

[0011] The purpose of this invention is to provide a device for placing and installing reinforcing cages for cast-in-place piles on soft soil foundations and its construction method, so as to solve the problems mentioned in the background art regarding the lack of quality assurance measures for placing and installing reinforcing cages, the high requirements for the accuracy of reinforcing cage alignment, and the difficulty in controlling the level and elevation of existing devices without anti-sinking and anti-floating measures.

[0012] To achieve the above objectives, the present invention provides the following technical solution: a steel drum casing for installing reinforcing cages in cast-in-place piles on soft soil and its construction method, comprising a steel drum casing with a worm gear rack lifting mechanism installed on the outside of the steel drum casing; a reinforcing cage support rod control mechanism installed inside the steel drum casing, wherein the driving device and the driven device of the reinforcing cage support rod control mechanism are connected by a stainless steel plate; a reinforcing cage bracket guide mechanism and a cam lifting mechanism installed inside the steel drum casing, and a self-locking mechanism provided within the cam lifting mechanism; through the reinforcing cage support rod control mechanism and the reinforcing cage bracket guide mechanism, the reinforcing cage can be transferred to the design specified elevation; the cam lifting mechanism pushes the telescopic rod outward; and the self-locking mechanism and the upward force of the second spring make the device self-lock.

[0013] Preferably, the worm gear rack lifting mechanism includes a worm gear, a rack, and a worm. The worm is rotatably connected to the inner side of the worm gear rack lifting mechanism, and the worm gear is meshed with the outer side of the worm. The rack is meshed with the outer side of the worm gear, and the rack is fixedly connected to the outer side of the steel drum casing.

[0014] Preferably, the rebar cage support rod control mechanism includes an annular pressure transmitting component and a sliding plate. The annular pressure transmitting component is fixedly connected to the outside of the outer rebar cage support rod control mechanism, and the sliding plate is fixedly connected to the outside of the annular pressure transmitting component.

[0015] Preferably, the cam lifting mechanism includes a telescopic rod and a first spring, the telescopic rod being slidably connected to the inner side of the cam lifting mechanism, and the first spring connecting the telescopic rod and the cam lifting mechanism.

[0016] Preferably, the self-locking mechanism further includes a slide groove, a second spring, and a slide rod. The slide groove is formed inside the self-locking mechanism, and the slide rod is slidably connected to the inside of the slide groove. The second spring is fixedly installed inside the slide groove, and the second spring and the slide rod are distributed vertically in correspondence.

[0017] A construction method for a reinforcement cage installation device for cast-in-place piles in soft soil foundations includes:

[0018] Step 1: Device Positioning

[0019] Based on the coordinates of the pile locations to be constructed, the center position of the pile hole is measured and marked with a total station and marked with a steel rebar head; a steel roll casing with a diameter and length that meets the site geological conditions is selected for the construction of the cast-in-place pile.

[0020] Step 2: Installation of the device

[0021] The length of the nylon line is the same as the radius of the steel drum casing. One end of the nylon line is tied to the center of the pile hole to position the rebar head. The other end of the nylon line is drawn along a circular trajectory and sprinkled with lime to determine the planar positioning of the steel drum casing. A vibratory pile driver is used to align the steel drum casing with the lime line and vibrate it to the designated elevation. The horizontal and verticality of the steel drum casing are then adjusted.

[0022] Step 3: Drilling of cast-in-place piles

[0023] Step 4: Lowering the steel cage

[0024] When lifting the first section of the steel cage, the elevation of the upper stiffening hoop of the steel cage is controlled to be 2-3cm above the telescopic rod of the steel cage bracket guide mechanism, leaving space for the telescopic rod to extend out.

[0025] Step 5: Adjust the reinforcing cage support rods

[0026] Pressing and releasing the control lever of the rebar cage support rod control mechanism activates the cam lifting mechanism, causing the slide plate to slide down, the telescopic rod to extend, and the rebar cage support rod control mechanism to self-lock.

[0027] (4) The pulley at the end of the telescopic rod rolls along the upper edge of the slide plate, pushing the first spring to compress, and the telescopic rod extends. The groove at the front end of the telescopic rod helps to fix the horizontal position of the steel cage.

[0028] (5) The sliding plate slides down and transmits pressure to the self-locking mechanism. The second spring is compressed, the free end of the slide rod slides along the slide groove 14 to the top groove, and the spring acts upward to lock the self-locking device.

[0029] (6) The active device and the driven device of the steel cage support rod control mechanism are connected by stainless steel plates. The force transmission of the driven device is consistent with the action of the active device. At this time, the three telescopic rods (one rod of the active device and two rods of the driven device) point to the center of the steel cage support guide mechanism on the same plane. The steel cage is slowly lowered and the first section of the steel cage is placed.

[0030] Step Six: Adjust the elevation of the rebar cage joint position

[0031] Controlling the worm gear and rack lifting mechanism involves rotating the rocker arm to drive the worm, which in turn drives the worm wheel to rotate. The worm wheel then drives the rack to move up and down. In this way, the joint position of the upper and lower steel cage sections can be adjusted, making it easier for workers to weld or connect the upper and lower steel cage sections using sleeves.

[0032] Step 7: Connect the reinforcing cages and lower them into place.

[0033] Lift the second section of the steel cage and reliably connect it to the first section. Lift the entire steel cage 2-3cm and press the control rod of the steel cage support rod control mechanism. The telescopic rod will retract into the steel cage support bracket guide mechanism. At this time, slowly lower the two sections of the steel cage to the construction operation surface where the second and third sections of the steel cage are connected. Press the control rod of the steel cage support rod control mechanism again. The telescopic rod will extend and the entire steel cage will be erected and fixed again.

[0034] After completing the designed steel cage length according to this method, the steel cage is fixed at the designed elevation by the worm gear rack lifting mechanism, and concrete is poured after secondary hole cleaning.

[0035] Once the concrete has been poured to approximately 85% of the designed volume, the position of the reinforcing cage is fixed. Adjust the worm gear and rack lifting mechanism, lowering the telescopic rod by 2-3 cm. Press the control rod of the reinforcing cage support rod control mechanism, and the telescopic rod retracts into the guide mechanism of the reinforcing cage support. Continue to control the worm gear and rack lifting mechanism to raise the guide mechanism of the reinforcing cage support to the top surface of the casing. Continue to pour concrete to the designed elevation of the pile top. Once the concrete reaches a certain strength, use a pile driver to remove the casing, and the pile formation is complete.

[0036] Compared with the prior art, the beneficial effects of the present invention are: the installation device for the reinforcing cage of the cast-in-place pile in soft soil foundation and its construction method:

[0037] (1) The turbine rack lifting mechanism and axial bracket guiding mechanism of the casing can be used to transfer the steel cage that has been connected as a whole to the design elevation, so as to ensure the construction quality at the pile head;

[0038] (2) By using the circumferential steel cage erection mechanism of the casing, while erecting the segmented steel cage and assisting in the connection between the upper and lower sections of the steel cage, the steel cage can be lowered straight, avoiding damage caused by the steel cage hitting the mud wall during the lowering process, causing construction quality problems such as hole collapse, ensuring the thickness of the concrete protective layer outside the steel cage, improving the construction quality of the pile body, and accelerating the construction progress.

[0039] (3) Adjust the level, elevation and verticality of the casing. The steel cage inside the casing is supported by three points of the support rod. The support rod is radially pointed to the center of the casing to ensure the verticality and horizontal position of the steel cage. Attached Figure Description

[0040] Figure 1This is an overall structural diagram of the reinforcement cage installation device for cast-in-place piles in weak soil foundations according to the present invention;

[0041] Figure 2 This is a diagram showing the internal structure of the casing of the present invention;

[0042] Figure 3 This is a structural diagram of the active device of the rebar cage support rod control mechanism of the present invention;

[0043] Figure 4 This is a structural diagram of the driven device of the rebar cage support rod control mechanism of the present invention;

[0044] Figure 5 This is a diagram showing the internal structure of the self-locking mechanism of the present invention;

[0045] Figure 6 This is a structural diagram of the internal structure of the worm gear rack lifting mechanism of the present invention;

[0046] Figure 7 This is a schematic diagram of the process for installing the reinforcing cage of a cast-in-place pile on a weak foundation, as described in an embodiment of the present invention.

[0047] In the diagram: 1. Worm gear and rack lifting mechanism; 2. Rebar cage support rod control mechanism; 3. Steel drum casing; 4. Rebar cage support guide mechanism; 5. Worm gear; 6. Rack; 7. Worm; 8. Annular pressure transmission component; 9. Cam lifting mechanism; 10. Slide plate; 11. Telescopic rod; 12. First spring; 13. Self-locking mechanism; 14. Slide groove; 15. Second spring; 16. Slide rod; 17. Stainless steel sheet. Detailed Implementation

[0048] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0049] Please see Figures 1-7 This invention provides a technical solution: a device for installing reinforcing cages for cast-in-place piles in soft soil foundations and its construction method, comprising:

[0050] Example 1: As Figures 1-6 The present invention provides a technical solution: a device for installing a reinforcing cage for a cast-in-place pile on a weak foundation and its construction method, which discloses: a steel drum casing 3, on the outside of which a worm gear and rack lifting mechanism 1 is installed; the worm gear and rack lifting mechanism 1 drives the steel drum casing 3 to move up and down through the cooperation of the worm wheel 5 and the worm 7, so that the reinforcing cage is transported to the designated elevation;

[0051] The steel cage support rod control mechanism 2 is installed inside the steel drum casing 3. The active device and the driven device of the steel cage support rod control mechanism 2 are connected by a stainless steel plate 17. The active device and the driven device of the steel cage support rod control mechanism 2 are connected by a stainless steel plate 17, and the force is transmitted through the connection of the stainless steel plate 17, so that the active device and the driven device move in unison.

[0052] The steel cage support guide mechanism 4 and the cam lifting mechanism 9 are installed inside the steel drum casing 3, and the self-locking mechanism 13 is located inside the cam lifting mechanism 9; the steel cage support guide mechanism 4 and the cam lifting mechanism 9 can ensure that the steel cage remains vertical when it is below, and avoid collisions and damage when it is below.

[0053] Through the steel cage support rod control mechanism 2 and the steel cage bracket guide mechanism 4, the steel cage can be transported to the design specified elevation. The telescopic rod 11 is pushed outward by the cam lifting mechanism 9, and the device is self-locked by the self-locking mechanism 13 and the upward force of the second spring 15.

[0054] The worm gear rack lifting mechanism 1 includes a worm wheel 5 and a worm 7. The worm 7 is rotatably connected to the inner side of the worm gear rack lifting mechanism 1, and the worm wheel 5 is meshed with the outer side of the worm 7. The rotation of the worm 7 drives the worm wheel 5 to rotate, which not only realizes the transmission of force, but also changes the direction of rotation.

[0055] The worm gear rack lifting mechanism 1 also includes a rack 6, which is meshed with the outside of the worm gear 5 and fixedly connected to the outside of the steel drum sleeve 3. The rack 6 meshes with the worm gear 5, and when the worm gear 5 rotates, it will drive the rack to move together, thereby driving the connected steel drum sleeve 3 to move together.

[0056] The rebar cage support rod control mechanism 2 includes an annular pressure transmission component 8, which is fixedly connected to the outside of the outer rebar cage support rod control mechanism 2; the annular pressure transmission component 8 can transmit force.

[0057] The steel cage support rod control mechanism 2 also includes a sliding plate 10, which is fixedly connected to the outside of the annular pressure transmission member 8. When the sliding plate 10 moves up and down, it will push the telescopic rod 11 outward through the protruding tail on the outside, thereby realizing the transmission of force.

[0058] The cam lifting mechanism 9 includes a telescopic rod 11, which is slidably connected to the inner side of the cam lifting mechanism 9; a first spring 12 is connected to the outer side of the telescopic rod 11, and the first spring 12 can cause the telescopic rod 11 to return to its original position by its own elastic force.

[0059] The cam lifting mechanism 9 also includes a first spring 12, the two ends of which are connected to the telescopic rod 11 and the cam lifting mechanism 9 respectively; the first spring 12 is connected in the middle part between the telescopic rod 11 and the cam lifting mechanism 9, which can not only realize the transmission of force but also play a certain buffering role;

[0060] The self-locking mechanism 13 also includes a slide groove 14 and a slide rod 16. The slide groove 14 is opened inside the self-locking mechanism 13, and the slide rod 16 is slidably connected to the inside of the slide groove 14.

[0061] The self-locking mechanism 13 also includes a second spring 15, which is fixedly connected to the inside of the slide groove 14, and the second spring 15 and the slide rod 16 are distributed vertically in correspondence; the slide rod 16 can be adjusted in position inside the slide groove to achieve self-locking.

[0062] Based on the pile location coordinates, this structure measures and marks the center position of the pile hole, selects a suitable steel drum casing 3 (the inner diameter should be 400mm larger than the pile diameter), and uses a nylon thread with the same length as the radius of the steel drum casing 3. One end is tied to the center positioning rebar of the pile hole, and lime is sprinkled along the circular path of the other end of the nylon thread to determine the planar positioning of the steel drum casing 3. According to the shallow soil conditions at the pile location, a vibratory pile driver is used to vibrate the steel drum casing 3 to the designated elevation, aligning it with the lime line. The horizontal and vertical alignment of the steel drum casing 3 is then adjusted. The first section of the reinforcing cage is lifted, and the first section is extended by pressing the reinforcing cage support rod control mechanism 2. After the extension rod 11 is fixed to the reinforcing cage bracket guide mechanism 4 inside the steel drum casing, the second section of the reinforcing cage is lifted and reliably connected to the first section. Pressing the rebar cage support rod control mechanism 2 causes the telescopic rod 11 to retract, at which point the two sections of the rebar cage are slowly lowered to the working surface where the second and third sections of the rebar cage connect. Pressing the rebar cage support rod control mechanism 2 again extends the telescopic rod 11, re-erecting and fixing the rebar cage. After completing the designed length of the rebar cage using this method, the rebar cage is fixed at the designed elevation using the worm gear and rack lifting mechanism 1. After a second cleaning of the hole, concrete is poured.

[0063] Example 2: Figure 7 As shown, the present invention provides a technical solution: a construction method for a reinforcement cage installation device for cast-in-place piles in weak soil foundations, which discloses:

[0064] Step 1: Device Positioning

[0065] Based on the coordinates of the pile location to be constructed, the center position of the pile hole is measured and marked with a total station and marked with a steel bar head; select a steel roll casing 3 with a diameter and length that meet the site geological conditions that the inner diameter should be 400mm larger than the pile diameter for the construction of the cast-in-place pile.

[0066] Step 2: Installation of the device

[0067] The length of the nylon line is the same as the radius of the steel drum casing 3. One end of the nylon line is tied to the center of the pile hole to position the rebar head. The other end of the nylon line is drawn along a circular trajectory and sprinkled with lime to determine the planar positioning of the steel drum casing 3. A vibratory pile driver is used to vibrate the steel drum casing 3 to the designated elevation by aligning it with the lime line. The horizontal and verticality of the steel drum casing 3 are then adjusted.

[0068] Step 3: Drilling of cast-in-place piles

[0069] Step 4: Lowering the steel cage

[0070] When lifting the first section of the steel cage, the elevation of the upper stiffening hoop of the steel cage is controlled to be 2-3cm above the telescopic rod 11 of the steel cage bracket guide mechanism 4, leaving space for the telescopic rod 11 to extend out.

[0071] Step 5: Adjust the reinforcing cage support rods

[0072] Pressing and releasing the control lever of the rebar cage support rod control mechanism 2, the cam lifting mechanism 9 is pressed, the slide plate 10 slides down, the telescopic rod 11 extends, and the rebar cage support rod control mechanism 2 self-locks.

[0073] (7) The pulley at the end of the telescopic rod 11 rolls along the upper edge of the slide plate 10, pushing the first spring 12 to compress, and the telescopic rod 11 extends. The groove at the front end of the telescopic rod 11 is conducive to fixing the horizontal position of the steel cage.

[0074] (8) The sliding plate 10 slides down and transmits pressure to the self-locking mechanism 13. The second spring 15 is compressed, and the free end of the slide rod 16 slides along the slide groove 14 to the top groove. The spring acts upward to self-lock the device.

[0075] (9) The active device and the driven device of the steel cage support rod control mechanism 2 are connected by stainless steel sheet 17. The force transmission of the driven device is consistent with the action of the active device. At this time, the active device of the three-bar steel cage support rod control mechanism 2 extends one bar, and the driven device extends two bars on the same plane pointing to the center of the steel cage support guide mechanism 4. The steel cage is slowly lowered, and the first section of the steel cage is placed.

[0076] Step Six: Adjust the elevation of the rebar cage joint position

[0077] Control the worm gear and rack lifting mechanism 1, rotate the rocker arm to drive the worm 7, the worm 7 rotates to drive the worm wheel 5 to rotate, and the worm wheel 5 drives the rack 6 to move up and down. In this way, the joint position of the upper and lower steel cages can be adjusted, so that workers can weld or sleeve the upper and lower steel cages according to the process requirements.

[0078] Step 7: Connect the reinforcing cages and lower them into place.

[0079] Lift the second section of the steel cage and reliably connect it to the first section of the steel cage; lift the entire steel cage by 2-3cm, press the control rod of the steel cage support rod control mechanism 2, and the telescopic rod 11 will retract into the steel cage support guide mechanism 4; at this time, slowly lower the two sections of the steel cage to the construction operation surface where the second and third sections of the steel cage are connected, press the control rod of the steel cage support rod control mechanism 2 again, the telescopic rod 11 will extend, and the entire steel cage will be erected and fixed again;

[0080] (1) After completing the designed length of the steel cage according to this method, the steel cage is fixed at the designed elevation by the worm gear rack lifting mechanism 1, and concrete is poured after the second cleaning of the hole.

[0081] (2) When the concrete is poured to about 85% of the design volume and does not exceed the bottom elevation of the casing, the position of the steel cage is fixed. Adjust the worm gear rack lifting mechanism 1, and the telescopic rod 11 is lowered by 2-3cm. Press the control rod of the steel cage support rod control mechanism 2, and the telescopic rod 11 is retracted into the steel cage support guide mechanism 4. Continue to control the worm gear rack lifting mechanism 1 to raise the steel cage support guide mechanism 4 to the top surface of the casing, and continue to pour concrete to the design elevation of the pile top. After the concrete reaches a certain strength, use a pile driver to remove the casing, and the pile is completed.

[0082] In the description of this invention, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention 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 the invention. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0083] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" 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. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0084] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A device for installing reinforcing cages for cast-in-place piles in soft soil foundations, characterized in that, include: A steel drum protector (3) is provided with a worm gear rack lifting mechanism (1) installed on the outside of the steel drum protector (3). The steel cage support rod control mechanism (2) is installed inside the steel drum casing (3). The active device and the driven device of the steel cage support rod control mechanism (2) are connected by a stainless steel sheet (17). The steel rebar cage bracket guide mechanism (4) and the cam lifting mechanism (9) are installed inside the steel drum casing (3), and the self-locking mechanism (13) is provided in the cam lifting mechanism (9). The steel cage is transported to the design elevation through the steel cage support rod control mechanism (2) and the steel cage bracket guide mechanism (4); The cam lifting mechanism (9) includes a telescopic rod (11), which is slidably connected to the inside of the cam lifting mechanism (9); The cam lifting mechanism (9) further includes a first spring (12), the two ends of which are connected to the telescopic rod (11) and the cam lifting mechanism (9), respectively; The self-locking mechanism (13) also includes a slide groove (14) and a slide rod (16). The slide groove (14) is opened inside the self-locking mechanism (13), and the slide rod (16) is slidably connected inside the slide groove (14). The self-locking mechanism (13) also includes a second spring (15), which is fixedly connected to the inside of the slide groove (14), and the second spring (15) and the slide rod (16) are distributed vertically in correspondence. The telescopic rod (11) is pushed outward by the cam lifting mechanism (9), and the device is self-locked by the self-locking mechanism (13) and the second spring (15) acting upward.

2. The device for installing reinforcing cages of cast-in-place piles in soft soil foundations according to claim 1, characterized in that: The worm gear rack lifting mechanism (1) includes a worm wheel (5) and a worm (7). The worm (7) is rotatably connected to the inner side of the worm gear rack lifting mechanism (1), and the worm wheel (5) is meshed with the outer side of the worm (7).

3. The device for installing reinforcing cages of cast-in-place piles in soft soil foundations according to claim 2, characterized in that: The worm gear rack lifting mechanism (1) also includes a rack (6), which is meshed with the outside of the worm gear (5) and fixedly connected to the outside of the steel drum sleeve (3).

4. A reinforcement cage installation device for cast-in-place piles in soft soil foundations according to any one of claims 1-3, characterized in that: The steel cage support rod control mechanism (2) includes an annular pressure transmission component (8), which is fixedly connected to the outside of the outer steel cage support rod control mechanism (2).

5. The device for installing reinforcing cages of cast-in-place piles in soft soil foundations according to claim 4, characterized in that: The steel cage support rod control mechanism (2) also includes a sliding plate (10), which is fixedly connected to the outside of the annular pressure transmission member (8).

6. An installation method for a reinforcing cage placement device for cast-in-place piles on weak foundations, implemented using the reinforcing cage placement device for cast-in-place piles on weak foundations as described in any one of claims 1-5, comprising: Step 1: Device Positioning Based on the coordinates of the pile location to be constructed, the center position of the pile hole is measured and marked with a total station and marked with a steel bar head; select a steel roll casing (3) with a diameter and length that meet the site geological conditions for the construction of the pile. Step 2: Installation of the device The length of the nylon line is the same as the radius of the steel drum casing (3). One end of the nylon line is tied to the center of the pile hole to position the steel bar head. The other end of the nylon line is drawn along the circular trajectory and sprinkled with lime to determine the plane positioning of the steel drum casing (3). A vibratory pile driver is used to align the steel drum casing (3) with the lime line and vibrate it to the designated elevation. The horizontal and verticality of the steel drum casing (3) are adjusted. Step 3: Drilling of cast-in-place piles Step 4: Lowering the steel cage Lift the first section of the steel cage and control the height of the upper stiffening hoop of the steel cage to be 2-3cm above the telescopic rod (11) of the steel cage bracket guide mechanism (4), and reserve space for the telescopic rod (11) to extend out. Step 5: Adjust the reinforcing cage support rods Pressing and releasing the rebar cage support rod control mechanism (2) active device control rod, cam lifting mechanism (9) is pressed, slide plate (10) slides down, telescopic rod (11) extends, rebar cage support rod control mechanism (2) self-locks: The pulley at the end of the telescopic rod (11) rolls along the upper edge of the slide plate (10), pushing the first spring (12) to compress, and the telescopic rod (11) extends. The groove at the front end of the telescopic rod (11) is conducive to fixing the horizontal position of the steel cage. The sliding plate (10) slides down and transmits pressure to the self-locking mechanism (13), the second spring (15) is compressed, the free end of the slide bar (16) slides along the slide groove (14) to the top groove, and the spring acts upward to lock the device. The active device and the driven device of the steel cage support rod control mechanism (2) are connected by a stainless steel sheet (17). The force transmission of the driven device is consistent with the action of the active device. At this time, the three rods of the telescopic rod (11), including the rod extended from the active device of the steel cage support rod control mechanism (2) and the two rods extended from the driven device, point to the center of the steel cage support guide mechanism (4) on the same plane. The steel cage is slowly lowered and the first section of the steel cage is placed. Step Six: Adjust the elevation of the rebar cage joint position Control the worm gear rack lifting mechanism (1), turn the rocker arm to drive the worm (7), the worm (7) rotates to drive the worm wheel (5) to rotate, and the worm wheel (5) then drives the rack (6) to move up and down. In this way, the joint position of the upper and lower steel cages can be adjusted, making it convenient for workers to weld or connect the upper and lower steel cages with sleeves. Step 7: Connect the reinforcing cages and lower them into place. Lift the second section of the steel cage and reliably connect it with the first section of the steel cage; lift the entire steel cage by 2-3cm, press the control rod of the steel cage support rod control mechanism (2), and the telescopic rod (11) retracts into the steel cage support guide mechanism (4); at this time, slowly lower the two sections of the steel cage to the construction operation surface where the second section of the steel cage connects with the third section of the steel cage, press the control rod of the steel cage support rod control mechanism (2) again, and the telescopic rod (11) extends out, and the entire steel cage is erected and fixed again; (1) After completing the designed length of the steel cage according to this method, the steel cage is fixed at the designed elevation by the worm gear rack lifting mechanism (1), and concrete is poured after the second cleaning of the hole. (2) When the concrete is poured to 85% of the design volume, the position of the steel cage is fixed. Adjust the worm gear rack lifting mechanism (1), and the telescopic rod (11) is lowered by 2-3cm. Press the control rod of the steel cage support rod control mechanism (2), and the telescopic rod (11) is retracted into the steel cage support guide mechanism (4). Continue to control the worm gear rack lifting mechanism (1) to lift the steel cage support guide mechanism (4) to the top surface of the casing. Continue to pour concrete to the design elevation of the pile top. After the concrete reaches a certain strength, use a pile driver to remove the casing and the pile is completed.

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