A pile foundation steel cage elevation and centering positioning device and method

Abstract

The present invention discloses a device and method for positioning the height and centering of a pile foundation steel cage. The positioning device comprises a positioning ring and a cross fixed inside the positioning ring and having an intersection at the center of the positioning ring. A positioning rod is vertically arranged at the intersection of the cross. At least one elevation rod is vertically arranged on the positioning ring. The elevation rod is provided with a scale. The bottom of the elevation rod is provided with a sleeve that is sleeved with the longitudinal reinforcement of the steel cage. The device and method for positioning the height and centering of a pile foundation steel cage of the present application is not only simple in structure, low in cost, easy to operate, reusable, and green and environmentally friendly, but also can speed up the speed and accuracy of the height and horizontal centering positioning of the steel cage during installation, thereby achieving the purpose of improving construction efficiency and quality and saving construction costs.

Description

Technical Field

[0001] The invention relates to the technical field of pile foundation construction, and in particular to a device and method for positioning the elevation and centering of a pile foundation reinforcement cage. Background Art

[0002] As a very important part of the structural force system, the importance of pile foundation construction quality is self-evident. Whether the center deviation of the pile foundation is within the specification is the primary criterion for judging whether a pile foundation is qualified. The installation of the steel cage is an important step in the construction of bored piles. If the center point deviation of the pile foundation steel cage installation is too large, it will cause eccentric compression of the pile foundation and reduce the ability of the pile foundation to bear loads, which poses a great quality risk. If the steel cage elevation control is not accurate, in order to ensure that the anchorage length of the longitudinal steel bars on the surface of the steel cage meets the requirements, cutting, lengthening and other measures must be taken in the later stage. No matter what remedial measures are taken, it will affect the progress and cost of the project. Therefore, in pile foundation construction, special attention should be paid to the step of steel cage installation and positioning.

[0003] The positioning of the steel cage includes elevation positioning and horizontal centering positioning. The elevation positioning of the steel cage refers to the positioning of the depth of the steel cage placed in the drilled hole. The traditional positioning method is to control the elevation of the steel cage by the length of the hanger. The disadvantages of this method are: there are deviations in the on-site cutting of the hanger, resulting in inaccurate elevation control of the steel cage. Furthermore, the hanger needs to be welded on-site, the process is cumbersome, and it cannot be reused, which is not conducive to cost control; the horizontal centering positioning of the steel cage refers to the overlapping positioning of the center axis of the steel cage and the center axis of the drilled hole or the eccentric positioning within the specified range. The traditional positioning method is to symmetrically set earrings or pads around each reinforcing hoop of the steel cage, and position it by contacting the earrings or pads with the drilled hole wall. However, since the hole wall is too soft, the earrings and pads may sink into one side of the hole wall, causing the steel cage to be displaced. Furthermore, when the empty part of the pile foundation is ≥2m or below the mud surface, it is difficult to position the pile foundation steel cage. The traditional approach is to extend the steel cage to the top elevation of the steel casing based on the original design length for centering. However, this method has the disadvantages of large amount of steel bars and non-reusability, which is not conducive to the cost control of the project. Traditional steel cage positioning.

[0004] There are many studies on the existing technology of steel cage positioning technology. For example, Chinese patent application number 201710980216.2 discloses a method for positioning a pile foundation steel cage hole, Chinese patent application number 201911152085.4 discloses a steel cage positioning and adjustment device and a steel cage centering device, and Chinese patent application number 201821798308.5 discloses a pile foundation steel cage installation and positioning device... These technologies all have the disadvantages of complex positioning structure and cumbersome positioning process, and cannot meet the requirements of elevation and centering positioning at the same time, which is not conducive to improving construction efficiency and saving construction costs. Summary of the invention

[0005] In view of this, the purpose of the present invention is to provide a pile foundation steel cage elevation and centering positioning device and method, which is not only simple in structure, low in cost, easy to operate, reusable, and green and environmentally friendly, but also can speed up the speed and accuracy of elevation and horizontal centering positioning during steel cage installation, thereby achieving the purpose of improving construction efficiency and quality and saving construction costs.

[0006] The present invention solves the above-mentioned problems through the following technical means: a pile foundation steel cage elevation and centering positioning device, comprising a positioning ring and a cross fixed on the inner side of the positioning ring and with the intersection located at the center of the positioning ring, a positioning rod is vertically arranged at the intersection of the cross; at least one elevation rod is vertically arranged on the positioning ring, the elevation rod is provided with a scale, and a sleeve is arranged at the bottom of the elevation rod and is sleeved with the longitudinal reinforcement of the steel cage.

[0007] Furthermore, a plurality of elevation rods are circumferentially arranged on the positioning ring, and a sleeve for sleeve-engaging with the longitudinal reinforcement corresponding to the steel cage is arranged at the bottom of each elevation rod.

[0008] Furthermore, the elevation rod is formed by splicing a plurality of graduated rods along the height direction.

[0009] Furthermore, one end of the scale rod is provided with a threaded head, and the other end is provided with a first threaded hole matching the threaded head. The top of the sleeve is provided with a second threaded hole matching the threaded head, and the scale rod at the bottom end is threadedly connected to the second threaded hole through the threaded head.

[0010] Furthermore, the elevation rod is connected to the positioning ring via a fixing clamp.

[0011] Furthermore, the fixing clamp includes a first clamping cavity, a second clamping cavity, a first locking screw and a second locking screw. The first clamping cavity and the second clamping cavity are fixedly connected. The elevation rod and the first clamping cavity are clamped and fixed by the first locking screw, and the positioning ring and the second clamping cavity are clamped and fixed by the second locking screw.

[0012] Furthermore, the positioning rod is a telescopic rod.

[0013] Furthermore, a notch is provided on the positioning ring.

[0014] A method for elevating and centering a pile foundation reinforcement cage using the above device comprises the following steps:

[0015] Construction preparation: Level the site and ensure that the foundation has sufficient bearing capacity to ensure that the drilling rig will not tilt, shift or sink during the drilling process;

[0016] Surveying and setting out: Determine the coordinates of the pile position according to the drawings, use the total station to accurately set out the pile position on site, mark the center of the pile position, and use the "cross line method" to measure and set out 4 guard piles around the pile position. The distance between the guard pile and the center point of the pile is determined according to the actual situation on site. The principle is that the guard pile will not be affected when the casing is buried, and the guard pile should be properly protected;

[0017] Burying casing: When burying casing, the central axis of the casing should be aligned with the pile position center measured and calibrated, and the casing should be buried vertically on the horizontal plane; compact and level the backfill soil around the casing to ensure that the casing is firmly buried;

[0018] Drilling: After the drilling rig is in place, use the automatic adjustment control system of the drilling rig to level the drilling rig and adjust the verticality of the drill rod to ensure the verticality of the pile hole. During the drilling process, it is necessary to ensure that the drill bit diameter matches the hole diameter and control the verticality of the drilling hole.

[0019] Steel cage production: The steel cage is produced according to the design requirements, with the reinforcement stirrups at the top of the last section of the steel cage as the elevation reference, and the part above the reinforcement stirrups is the steel cage anchorage area;

[0020] Steel cage installation:

[0021] S1: Use a crane to lower the steel cage into the borehole. When the elevation benchmark is flush with the top of the casing, stop lowering the steel cage;

[0022] S2: The elevation rod is sleeved on the longitudinal reinforcement in the anchorage area of ​​the steel cage through a sleeve. The scale on the elevation rod is referenced to the elevation benchmark. Then, the steel cage is lowered to a specified depth with reference to the scale on the elevation rod, thereby realizing the elevation positioning of the lowered steel cage.

[0023] S3: Install the positioning ring on the elevation rod;

[0024] S4: Use the “cross line method” to restore the pile position center from the pile guide line;

[0025] S5: Move the steel cage so that the positioning rod on the positioning ring coincides with the center line of the drill hole or is within the specified eccentric range, thereby completing the centering positioning of the steel cage;

[0026] Remove the positioning device.

[0027] Furthermore, when the steel cage is manufactured, multiple layers of spacer blocks are arranged longitudinally along the steel cage, each layer of spacer block group includes multiple spacers uniformly arranged circumferentially on the side wall of the steel cage, and the spacers of adjacent layers are staggered circumferentially.

[0028] Beneficial effects of the present invention: The elevation and centering positioning device and method of the pile foundation steel cage of the present invention, the positioning device, comprises a positioning ring and a cross fixed inside the positioning ring and having an intersection at the center of the positioning ring, a positioning rod is vertically arranged at the intersection of the cross; at least one elevation rod with a scale is vertically arranged on the positioning ring, and a sleeve is arranged at the bottom of the elevation rod to be sleeved with the longitudinal reinforcement of the steel cage. The elevation and centering positioning device and method of the pile foundation steel cage of the present application is not only simple in structure, low in cost, easy to operate, reusable, and green and environmentally friendly, but also can speed up the speed and accuracy of elevation and horizontal centering positioning during steel cage installation, thereby achieving the purpose of improving construction efficiency and quality and saving construction costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0030] Figure 1 It is a schematic diagram of the overall structure of an embodiment of the present invention;

[0031] Figure 2 It is a partial structural schematic diagram of an embodiment of the present invention;

[0032] Figure 3 It is a structural schematic diagram of a scale rod according to an embodiment of the present invention;

[0033] Figure 4 It is a schematic structural diagram of a sleeve according to an embodiment of the present invention;

[0034] Figure 5 Schematic diagram of the structure of the fixing clip according to an embodiment of the present invention. DETAILED DESCRIPTION

[0035] The present invention will be described in detail below with reference to the accompanying drawings.

[0036] like Figure 1-5As shown: This embodiment provides a pile foundation steel cage elevation and centering positioning device for a pile with a pile diameter of 1m and a main reinforcement of a steel cage of φ14, including a positioning ring 1, a cross 2, a positioning rod 3 and an elevation rod. The positioning ring 1 and the cross 2 are both made of φ14 steel bars. The diameter of the positioning ring 1 is the same as the diameter of the reinforcing stirrups of the steel cage. Four notches 101 are evenly opened on the positioning ring 1 in the circumferential direction to facilitate the entry of the sling. The cross 2 is fixed to the inner side of the positioning ring 1, and the intersection of the cross 2 is at the center of the positioning ring 1. A positioning rod 3 is vertically arranged at the intersection of the cross 2. Preferably, the positioning rod 3 is a telescopic rod, so that when centering, the length can be adjusted to be flush with the height of the pile position center restored from the pile protection lead, thereby reducing the visual error during centering. It is necessary to explain that in some preferred embodiments, the positioning ring 1, the cross 2 and the positioning rod 3 are welded into a whole to improve the convenience of installation. The positioning ring 1 is vertically provided with a plurality of elevation rods with scales, and the plurality of elevation rods are evenly arranged around the positioning ring 1. The bottom of each elevation rod is provided with a sleeve 5 which is sleeved with the corresponding longitudinal reinforcement in the anchoring area of ​​the steel cage. Preferably, the elevation rod is formed by splicing a plurality of scale rods 4 along the height direction. Specifically, Figure 3 As shown, the scale rod 4 is composed of The rod is made of steel bars, one end of which is integrally processed with a thread head 402, and the other end is provided with a first threaded hole 401 matching the thread head. Generally speaking, each scale rod 4 is 1m long, and the tapping length of the thread head 402 and the first threaded hole 401 is 50mm. A scale marking the height is set on the rod body, and a mark is made every 10cm. Figure 4 As shown, the top of the sleeve 5 is provided with a second threaded hole 501 matching the threaded head 402, the depth of the second threaded hole 501 is not less than 50mm, the sleeve has an outer diameter of 22mm, an inner diameter of 18mm, and a length of 1m. The scale rod 4 at the bottom is threadedly connected to the second threaded hole 501 through the threaded head 402. When the scale rods are spliced, the threaded head of one scale rod is threadedly connected to the first threaded hole of another scale rod. With this assembled structure, the overall height of the elevation rod can be adjusted as needed to meet the elevation positioning requirements of different steel cages.

[0037] As a further improvement to the above technical solution, the elevation rod is connected to the positioning ring through a fixing clamp 6, such as Figure 5As shown, the fixing clamp includes a first clamping cavity 602, a second clamping cavity 603, a first locking screw 601 and a second locking screw 604. The first clamping cavity 602 and the second clamping cavity 603 are welded and fixed. The elevation rod vertically passes through the first clamping cavity 602, and the elevation rod and the first clamping cavity 602 are clamped and fixed by the first locking screw 601. The positioning ring 1 horizontally passes through the second clamping cavity 603, and the positioning ring 1 and the second clamping cavity 603 are clamped and fixed by the second locking screw 604. The fixing clamp with this structure can not only adjust the position vertically relative to the elevation rod, but also adjust the position circumferentially relative to the positioning ring, which greatly improves the convenience of installation.

[0038] This embodiment also provides a method for elevating and centering a pile foundation reinforcement cage using the above device, comprising the following steps:

[0039] Construction preparation: Level the site and ensure that the foundation has sufficient bearing capacity to ensure that the drilling rig will not tilt, shift or sink during the drilling process;

[0040] Measurement and setting out: According to the drawings, determine the coordinates of the pile position, use the total station to accurately set out the pile position on site, mark the center of the pile position, and use the "cross-line method" to measure and set out 4 guard piles around the pile position. The distance between the guard pile and the center point of the pile is determined according to the actual situation on site. The guard pile should not be affected when the casing is buried. The guard pile should be properly protected. The cross-line method means: draw two perpendicular intersecting lines, and the intersection of the two intersection lines is on the central axis of the pile position;

[0041] Burying casing: When burying casing, the central axis of the casing should be aligned with the pile position center measured and calibrated, and the casing should be buried vertically on the horizontal plane; compact and level the backfill soil around the casing to ensure that the casing is firmly buried;

[0042] Drilling: After the drilling rig is in place, use the automatic adjustment control system of the drilling rig to level the drilling rig and adjust the verticality of the drill rod to ensure the verticality of the pile hole. During the drilling process, it is necessary to ensure that the drill bit diameter matches the hole diameter and control the verticality of the drilling hole.

[0043] Steel cage production: The steel cage is produced according to the design requirements, with the reinforcement stirrups at the top of the last section of the steel cage as the elevation reference, and the part above the reinforcement stirrups is the steel cage anchorage area;

[0044] Steel cage installation:

[0045] S1: Use a crane to lower the steel cage into the borehole. When the elevation benchmark is flush with the top of the casing, stop lowering the steel cage;

[0046] S2: The elevation rod is sleeved on the longitudinal reinforcement in the anchorage area of ​​the steel cage through a sleeve. The scale on the elevation rod is referenced to the elevation benchmark. Then, the steel cage is lowered to a specified depth with reference to the scale on the elevation rod, thereby realizing the elevation positioning of the lowered steel cage.

[0047] S3: Install the positioning ring on the elevation rod;

[0048] S4: Use the “cross line method” to restore the pile position center from the pile guide line;

[0049] S5: Move the steel cage so that the positioning rod on the positioning ring coincides with the center line of the drill hole or is within the specified eccentric range, thereby completing the centering positioning of the steel cage;

[0050] Remove the positioning device.

[0051] As a further improvement to the above technical solution, when the steel cage is manufactured, multiple layers of pad blocks are arranged longitudinally along the steel cage, and each layer of pad blocks includes multiple pad blocks evenly arranged circumferentially on the side wall of the steel cage, and pad blocks of adjacent layers are staggered circumferentially. On the one hand, the pad blocks can be used as an auxiliary reference for the centering and positioning of the steel cage, and on the other hand, in order to prevent the steel cage from rusting, it is usually necessary to cast a protective layer between the outer wall of the steel cage and the borehole wall, and the pad blocks can be used as a reference for the thickness of the protective layer.

[0052] To sum up, the pile foundation steel cage elevation and centering positioning device and method of the present embodiment are not only simple in structure, low in cost, easy to operate, reusable, and environmentally friendly, but also can speed up the speed and accuracy of elevation and horizontal centering positioning during steel cage installation, thereby achieving the purpose of improving construction efficiency and quality and saving construction costs.

[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A method for elevating and centering a pile foundation reinforcement cage, characterized in that: The device used includes a positioning ring and a cross fixed inside the positioning ring and having an intersection at the center of the positioning ring, a positioning rod is vertically arranged at the intersection of the cross; at least one elevation rod is vertically arranged on the positioning ring, a scale is arranged on the elevation rod, and a sleeve is arranged at the bottom of the elevation rod to be sleeved with the longitudinal reinforcement of the steel cage; The elevation rod is connected to the positioning ring via a fixing clamp; The fixing clamp comprises a first clamping cavity, a second clamping cavity, a first locking screw and a second locking screw, the first clamping cavity and the second clamping cavity are fixedly connected, the elevation rod and the first clamping cavity are clamped and fixed by the first locking screw, and the positioning ring and the second clamping cavity are clamped and fixed by the second locking screw; The steps include: Construction preparation: Level the site and ensure that the foundation has sufficient bearing capacity to ensure that the drilling rig will not tilt, shift or sink during the drilling process; Surveying and setting out: According to the drawings, determine the coordinates of the pile position, use the total station to accurately set out the pile position on site, mark the center of the pile position, and use the "cross line method" to measure and set out 4 guard piles around the pile position. The distance between the guard pile and the center point of the pile is determined according to the actual situation on site. The principle is that the guard pile will not be affected when the casing is buried, and the guard pile should be properly protected; Burying casing: When burying casing, the central axis of the casing should be aligned with the pile position center measured and calibrated, and the casing should be buried vertically on the horizontal plane; compact and level the backfill soil around the casing to ensure that the casing is firmly buried; Drilling: After the drilling rig is in place, use the automatic adjustment control system of the drilling rig to level the drilling rig and adjust the verticality of the drill rod to ensure the verticality of the pile hole. During the drilling process, it is necessary to ensure that the drill bit diameter matches the hole diameter and control the verticality of the drilling hole. Steel cage production: The steel cage is produced according to the design requirements, with the reinforcement stirrups at the top of the last section of the steel cage as the elevation reference, and the part above the reinforcement stirrups is the steel cage anchorage area; Steel cage installation: S1: Use a crane to lower the steel cage into the borehole. When the elevation benchmark is flush with the top of the casing, stop lowering the steel cage; S2: The elevation rod is sleeved on the longitudinal reinforcement in the anchorage area of ​​the steel cage through a sleeve. The scale on the elevation rod is referenced to the elevation benchmark. Then, the steel cage is lowered to a specified depth with reference to the scale on the elevation rod, thereby realizing the elevation positioning of the lowered steel cage. S3: Install the positioning ring on the elevation rod; S4: Use the "cross line method" to restore the pile position center from the pile guide line; S5: Move the steel cage so that the positioning rod on the positioning ring coincides with the center line of the drill hole or is within the specified eccentric range, thereby completing the centering positioning of the steel cage; Disassemble the positioning device; The positioning rod is a telescopic rod.

2. The method for elevating and centering a pile foundation reinforcement cage according to claim 1, characterized in that: A plurality of elevation rods are arranged circumferentially on the positioning ring, and a sleeve for sleeve-engaging with the longitudinal reinforcement corresponding to the steel cage is arranged at the bottom of each elevation rod.

3. The method for elevating and centering a pile foundation reinforcement cage according to claim 2 is characterized in that: The elevation rod is formed by splicing a plurality of scale rods along the height direction.

4. The method for elevating and centering a pile foundation reinforcement cage according to claim 3 is characterized in that: One end of the scale rod is provided with a threaded head, and the other end is provided with a first threaded hole matching the threaded head. The top of the sleeve is provided with a second threaded hole matching the threaded head, and the scale rod at the bottom end is threadedly connected with the second threaded hole through the threaded head.

5. The method for elevating and centering a pile foundation reinforcement cage according to claim 1, characterized in that: A notch is provided on the positioning ring.

6. The method for elevating and centering a pile foundation reinforcement cage according to claim 1, characterized in that: When the steel cage is manufactured, multiple layers of spacer blocks are arranged longitudinally along the steel cage. Each layer of spacer block group includes multiple spacers uniformly arranged circumferentially on the side wall of the steel cage, and the spacers of adjacent layers are staggered circumferentially.

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