Precise positioning system and method for bridge cast-in-situ bored pile

Abstract

The invention relates to the technical field of constructional engineering, in particular to an accurate positioning system and method for a bridge cast-in-situ bored pile. The system comprises an earth surface positioning mechanism and a suspension positioning mechanism, and the method comprises the processes of respective assembly and in-place matching of the earth surface positioning mechanism and the suspension positioning mechanism. The invention provides a modularized and assembled accurate positioning system for the bridge cast-in-situ bored pile, and provides a standardized method for construction outside a drill hole. The axis of the reinforcement cage A can coincide with the axis of the drill hole through positioning outside the drill hole, the operation difficulty is greatly reduced while the reinforcement cage A is accurately positioned, the practicability of the positioning system is improved, and the positioning system is worthy of application and popularization.

Description

Technical Field

[0001] The invention relates to the technical field of construction engineering, and in particular to a precise positioning system and method for bored cast-in-place piles of bridges. Background Art

[0002] Bored piles refer to piles that are made by forming a pile hole in the foundation soil through mechanical drilling, manual excavation and other means at the construction site, placing a steel cage inside, and pouring concrete. After the steel cage is placed inside the pile hole, it is necessary to ensure that the thickness of the concrete wrapped around the steel cage is consistent to prevent the steel cage structure inside the thinner concrete thickness from being easily corroded. Therefore, when placing the steel cage into the pile hole, it is necessary to position the steel cage to ensure that the center of the steel cage and the center of the pile hole are on the same axis. The current conventional practice is to use a crane to lift the steel cage, which requires multiple measurements and adjustments to move the steel cage to the center of the pile hole, and then slowly place the steel cage into the pile hole. This has the problems of difficult operation and low efficiency.

[0003] Existing patent documents also disclose some precise positioning devices for bored cast-in-place piles for bridges (e.g., patent CN118997123 A discloses a tool-based rapid positioning construction method for bored cast-in-place pile reinforcement cages), but most of these devices position the reinforcement cage inside the borehole, which not only has a complex mechanical structure and is difficult to operate, but is also not very practical. Summary of the invention

[0004] The present invention provides a precise positioning system and method for bored piles of bridges, aiming to solve the problems described in the background technology part.

[0005] To solve the above problems, the technical solution of the present invention is:

[0006] A precise positioning system for bored piles of bridges, comprising a surface positioning mechanism and a suspension positioning mechanism, wherein the surface positioning mechanism comprises four linear positioning grooves arranged on the ground where the outer periphery of a steel casing at the top of the borehole is located, the four linear positioning grooves are connected to the steel casing through the steel casing positioning mechanism and have the same slope, and the steel casing positioning mechanism is used to make the four linear positioning grooves evenly distributed around the axis of the borehole and the center line of the linear positioning grooves is coplanar with the axis of the borehole; the suspension positioning mechanism comprises a suspension plate, a guide rod, a roller, and a positioning steel cage, and the top of the suspension plate is connected to the steel casing through a steel wire The rope is connected to the lifting equipment, and four guide rods are evenly distributed around the axis on the suspension plate. Rollers are provided at the bottom of the guide rods. The four rollers are used in conjunction with four linear positioning grooves respectively. The suspension plate is penetrated by a positioning steel cage in the longitudinal direction and is fixedly connected to the positioning steel cage. The bottom of the positioning steel cage is coaxially welded to the inner or outer side of the top of the steel cage A to be placed in the drill hole, and the axis of the steel cage A is made to coincide with the central axis of the suspension plate. When the four rollers are in place with the linear positioning grooves, the steel cage A is inserted into the set position in the drill hole and the axis of the steel cage A coincides with the axis of the drill hole.

[0007] Preferably, a through hole is provided in the middle of the suspension plate, and the through hole is coaxially arranged with the steel cage A. The through hole is used to insert a conduit for pouring concrete to pour the steel cage in place.

[0008] Preferably, the steel casing is coaxial with the borehole, and the top of the steel casing extends out of the ground. The steel casing positioning mechanism includes a vertical cylinder coaxially sleeved outside the steel casing and loosely matched with the steel casing, and an annular bottom plate perpendicular to the axis of the vertical cylinder and coaxially welded to the lower end of the outer periphery of the vertical cylinder. A connecting hole for connecting a lifting equipment is provided on the annular bottom plate, and 4 linear positioning grooves are distributed on the outer surface of the annular bottom plate at 90° intervals, and the bottom of the groove is inclined downward toward one side of the steel casing. The linear positioning groove is connected to the annular bottom plate through a lifting mechanism.

[0009] Preferably, a first limit block is provided in the linear positioning groove, and the four first limit blocks have the same structural shape and are in the same height relative to the annular bottom plate; the lifting mechanism includes four supporting legs arranged on the side wall of the linear positioning groove along the longitudinal direction, and the bottom ends of the four supporting legs are fixedly connected with a pad, and the pad is detachably fixedly connected to the bottom plate by bolts, and the supporting legs are a telescopic structure and are used to adjust the height of the linear positioning groove.

[0010] Preferably, the supporting leg is a hydraulic cylinder, an electric cylinder or a pneumatic cylinder, the fixed end of the telescopic structure is fixedly connected to the side wall of the linear positioning groove, and the telescopic end is fixedly connected to the pad.

[0011] Preferably, the suspension plate is a cubic structure, and the four corners of the suspension plate are respectively provided with guide holes inclined outward and with the same inclination, a linear bearing is fixedly provided in the guide hole, the guide rod passes through the linear bearing and slides with the linear bearing, a second limit block is provided on the top of the guide rod, and a third limit block is provided on the bottom of the guide rod near the roller, and a fourth limit block used in conjunction with the third limit block is provided at the four corners of the lower surface of the suspension plate.

[0012] Preferably, a plurality of first longitudinal bars are evenly welded to the outer periphery of the positioning steel cage, and the first longitudinal bars are welded to the inner or outer side of the second longitudinal bars of the steel cage A. The first longitudinal bars extend upward to form a guide section, and the guide section passes through a guide connecting hole which is vertically preset on the suspension plate and located at the outer periphery of the through hole. A threaded section is provided on the upper part of the guide section, and a limiting nut is screwed on the threaded section.

[0013] Preferably, the upper and lower end surfaces of the suspension plate are square, the four first limit blocks are consistent with the axis of the steel casing, the upper surface of the suspension plate is rectangularly arranged with four first lifting rings, the first lifting rings are respectively connected to steel wire ropes, the tops of the four steel wire ropes are commonly connected to a second lifting ring, and the second lifting ring is connected to the hook of the lifting equipment.

[0014] A method for positioning outside a bored pile of a bridge for accurate positioning, comprising the following steps:

[0015] (1) Weld the positioning steel cage coaxially on the top of the steel cage A, so that the first longitudinal reinforcement of the positioning steel cage is welded to the inside or outside of the second longitudinal reinforcement of the steel cage A, ensuring that the steel cage A is coaxial with the positioning steel cage;

[0016] (2) The steel cage A is tilted and placed by the bracket so that the guide section of each first longitudinal reinforcement passes through the guide connection hole, and then the limit nut is tightened. At this time, the upper and lower ends of the suspension plate are coaxial with the axis of the positioning steel cage and the steel cage A respectively and are perpendicular to each other;

[0017] (3) The ground around the borehole is leveled, and the surface positioning mechanism is lifted to the position of the steel casing by a lifting device, so that the vertical tube is set outside the steel casing, the lower part of the annular bottom plate is padded, and each linear positioning groove is adjusted to the same height;

[0018] (4) The lifting device is connected to the second lifting ring, and the suspension positioning mechanism is lifted as a whole through the suspension plate;

[0019] (5) The lifting equipment places the steel cage A into the drill hole, and makes the four rollers contact with the corresponding linear positioning grooves respectively. Due to the effect of gravity, the bottom end of the second limit block contacts with the top of the suspension plate at first. As the suspension plate is lowered, the guide rod slides upward along the linear bearing and the roller slides downward along the linear positioning groove. Finally, the roller abuts against the first limit block, and the third limit block abuts against the fourth limit block. At this time, the suspension plate is located at the preset position and the axes of the suspension plate, the through hole, the positioning steel cage, and the steel cage A coincide with the axis of the drill hole. The steel cage A is placed at the preset depth in the drill hole.

[0020] (6) After the guide tube is inserted through the through hole and the cast-in-place pile is formed, the excess positioning steel cage is cut off, and the suspension positioning mechanism is lifted away by the lifting equipment. The bottom of the positioning steel cage of the cut-off part of the steel cage is re-welded with a steel cage of the same size and structure as the cut-off steel cage, so as to be used for the next drilling positioning.

[0021] The precise positioning system and method of bored piles for bridges of the present invention have the following beneficial effects:

[0022] (1) The present invention can achieve the coincidence of the axis of the steel cage A with the axis of the drill hole by positioning outside the drill hole. While accurately positioning the steel cage A, it greatly reduces the difficulty of operation and improves the practicality of the positioning system, which is worthy of popularization and use.

[0023] (2) The present invention can greatly improve the efficiency of positioning the steel cage A. When in use, the steel cage A can be made coaxial with the drill hole through simple steps.

[0024] (3) The annular base plate and the vertical tube of the present invention are provided with various models according to the different sizes of the steel casing, and can be replaced according to the needs. The positioning steel cage can be reused repeatedly. The surface positioning mechanism and the suspension positioning mechanism can be accurately prefabricated in the factory according to the construction situation. After arriving at the construction site, the positioning casting of the steel hole A can be realized quickly and efficiently.

[0025] (4) As described above, the present invention provides a modular, assembled bridge bored pile precision positioning system and provides a standardized method for out-of-drilling construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 , the initial state intention of the present invention during construction;

[0027] Figure 2 , a schematic top view of the surface positioning mechanism of the present invention;

[0028] Figure 3 , a schematic diagram of the surface positioning mechanism and the suspension positioning mechanism of the present invention when they are in place;

[0029] Figure 4 , a top view schematic diagram of the suspension positioning mechanism of the present invention;

[0030] In the figure: 1-steel casing, 2-surface positioning mechanism, 3-drilling hole, 4-suspension plate, 5-linear bearing, 6-guide rod, 7-second limit block, 8-third limit block, 9-roller, 10-first lifting ring, 11-wire rope, 12-second lifting ring, 13, steel cage A; 14: positioning steel cage, 15: first longitudinal reinforcement, 16: limit nut, 17: through hole, 18: guide section, 19: fourth limit block, 201: annular bottom plate, 202: linear positioning groove, 203: support leg, 204: first limit block, 205: vertical cylinder. DETAILED DESCRIPTION

[0031] The following describes in detail the implementation mode of the present invention in a step-by-step manner. The description is only a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

[0032] In the description of the present invention, it should be noted that the directions or positional relationships indicated by terms such as “upper”, “lower”, “left”, “right”, “top”, “bottom”, “inside” and “outside” are based on the directions or positional relationships shown in the accompanying drawings, and are only for the purpose of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, and a specific direction structure and operation, and therefore cannot be understood as a limitation on the present invention.

[0033] Example 1

[0034] A precise positioning system for bored piles of bridges, such as Figure 1-4 As shown, it includes a surface positioning mechanism and a suspension positioning mechanism, wherein the surface positioning mechanism is used to establish a correlated positional relationship with the drill hole outside the drill hole, that is, through this positional relationship, the following four first limit plates 204 can indirectly limit the suspension plate to be coaxial with the drill hole, and then limit the through hole to be coaxial with the drill hole, and then limit the steel cage A to be coaxial with the drill hole.

[0035] The suspension positioning mechanism realizes its own precise positioning by cooperating with the surface positioning mechanism on the basis of the precise positioning of the surface positioning mechanism relative to the borehole, and on the basis of its own precise positioning, the steel cage A is precisely positioned in the borehole at a position coaxial with the borehole;

[0036] Specifically: the surface positioning mechanism includes four linear positioning grooves 202 arranged on the ground where the outer periphery of the steel casing 1 at the top of the borehole 3 is located. The four linear positioning grooves 202 are connected to the steel casing 1 through the steel casing positioning mechanism and have the same slope. The steel casing positioning mechanism makes the four linear positioning grooves 202 evenly distributed around the axis of the borehole 3 and the center line of the linear positioning groove is coplanar with the axis of the borehole.

[0037] like Figure 2 As shown; the suspension positioning mechanism includes a suspension plate 4, a guide rod 6, a roller 9, and a positioning steel cage 14. The top of the suspension plate 4 is connected to the lifting equipment through a wire rope 11. Four guide rods 6 are evenly distributed around the axis on the suspension plate 4. Rollers 9 are provided at the bottom of the guide rods 6. The four rollers 9 are respectively used in conjunction with four linear positioning grooves 202. The suspension plate 4 is penetrated by a positioning steel cage 14 in the longitudinal direction and is fixedly connected to the positioning steel cage 14.

[0038] The bottom of the positioning steel cage 14 is coaxially welded to the inner or outer side of the top of the steel cage A13 to be placed in the bore hole 3, and the axis of the steel cage A13 coincides with the central axis of the suspension plate 4. When the four rollers 9 are in place with the linear positioning groove 202, the steel cage A13 is inserted into the set position in the bore hole 3 and the axis of the steel cage A13 coincides with the axis of the bore hole 3.

[0039] Example 2

[0040] like Figure 1-4 As shown, a through hole 17 is provided in the middle of the suspension plate 4, and the through hole 17 is coaxially arranged with the steel cage A13. The through hole 17 is used to insert a conduit for pouring concrete to pour the steel cage in place.

[0041] Example 3

[0042] like Figure 1-4 As shown, the steel casing 1 is coaxial with the borehole 3 (achieved here through previous engineering), and the top of the steel casing 1 extends out of the ground. The steel casing positioning mechanism includes a vertical tube 205 coaxially sleeved outside the steel casing 1 and gap-matched with the steel casing 1 (both to ensure convenient sleeve installation and to ensure the coaxiality of the two, so the gap between the vertical tube and the steel casing should be as small as possible, for example, the gap is 1 mm), and an annular bottom plate 20 perpendicular to the axis of the vertical tube 205 and coaxially welded to the lower end of the outer periphery of the vertical tube 205.

[0043] The annular bottom plate 201 is provided with a connection hole (not shown) for connecting a lifting device, and four linear positioning grooves 202 are distributed on the outer surface of the annular bottom plate 201 at intervals of 90°, and the bottom of the groove is inclined downward toward one side of the steel casing 1, and the linear positioning grooves 202 are connected to the annular bottom plate through a lifting mechanism.

[0044] It can be understood that since the vertical cylinder is coaxial with the steel casing and the annular base plate and the vertical cylinder is perpendicular to the annular base plate, it is ensured that the upper surface of the annular base plate is located in a plane perpendicular to the axis direction of the drilling hole, thereby achieving the basic positioning of the four linear positioning grooves; on this basis, further, the four linear positioning grooves 202 are distributed at 90° intervals on the outer surface of the annular base plate 201, that is, the positioning of the positional relationship between the four linear positioning grooves is achieved, so as to facilitate coordination with the suspension plate.

[0045] like Figure 1-4 As shown, a first limit block 204 is provided in the linear positioning groove 202, and the four first limit blocks 204 have the same structural shape and are at the same height relative to the annular bottom plate 201 (i.e., the four rollers can be restricted to the same height relative to the axial direction of the drilling hole through the four first limit blocks).

[0046] The lifting mechanism includes four supporting legs 203 longitudinally arranged on the side walls of the linear positioning groove 202. The bottom ends of the four supporting legs 203 are fixedly connected with pads (not marked in the figure). The pads are detachably fixedly connected to the annular bottom plate 201 by bolts (to facilitate replacement of annular bottom plates and vertical cylinders of different specifications). The supporting legs 203 are telescopic structures and are used to adjust the height of the linear positioning groove 202, so that the suspension plate is located at a set height, which is convenient for entering below the suspension plate to manually cut and position the steel cage or perform other construction operations.

[0047] Example 4

[0048] like Figure 1-4 As shown, the support leg 203 is a hydraulic cylinder or an electric cylinder or a gas cylinder, the fixed end of the telescopic structure is fixedly connected to the side wall of the linear positioning groove 202, and the telescopic end is fixedly connected to the pad;

[0049] like Figure 1-4 As shown, the suspension plate 4 is a cubic structure, and the four corners of the suspension plate 4 are respectively provided with guide holes inclined outward and with the same inclination, a linear bearing 5 is fixedly provided in the guide hole, the guide rod 6 passes through the linear bearing 5 and slides with the linear bearing 5, a second limit block 7 is provided on the top of the guide rod 6 (to prevent the guide rod from slipping and limit the initial position of the guide rod), a third limit block 8 is provided at the bottom of the guide rod 6 near the roller 9, and a fourth limit block 19 used in conjunction with the third limit block 8 is provided at the four corners of the lower surface of the suspension plate 4.

[0050] In this embodiment, when the roller abuts against the first limit block and the third limit block abuts against the fourth limit block, it means that the suspension plate and the linear positioning groove are in place. Since the four first limit blocks are consistent in height relative to the annular bottom plate, the sizes of each third limit block, each fourth limit block and each guide rod are the same, and the four guide rods have the same inclination, when they are in place, the suspension plate is located above the steel casing, perpendicular to the drilled hole and coaxial with the drilled hole. Since the through hole is coaxial with the suspension plate, the positioning steel cage and steel cage A are coaxial with the suspension plate, the steel cage A is coaxial with the drilled hole.

[0051] Example 5

[0052] like Figure 1-4 As shown, a plurality of first longitudinal bars 15 are uniformly welded on the outer periphery of the positioning steel bar cage 14, and the first longitudinal bars 15 are welded to the inner or outer side of the second longitudinal bars of the steel bar cage A13 (such fitting welding ensures that the steel bar hole A is coaxial with the positioning steel bar hole, wherein the first longitudinal bars are preferably welded to the inner side of the second longitudinal bars), and the first longitudinal bars 15 extend upward to form a guide section 18.

[0053] The guide section passes through a guide connecting hole (not marked in the figure) which is vertically preset on the suspension plate 4 and located on the periphery of the through hole 17. A threaded section is provided on the upper part of the guide section, and a limiting nut 16 is screwed on the threaded section. The above arrangement ensures that the positioning steel cage is coaxial with the suspension plate, which indirectly limits the coaxiality of the steel cage A and the suspension plate.

[0054] Example 6

[0055] like Figure 1-4 As shown, the upper and lower end surfaces of the suspension plate 4 are square, and the four first limit blocks are consistent with the axis of the steel casing 1, that is, Figure 3 , 4 As shown, a regular tetrahedral structure is formed between the plane formed by the upper end surface of the suspension plate and the line connecting the bottom ends of the four rollers, combined with the axis of the guide rod, which limits the suspension plate to be parallel and coaxial with the annular bottom plate; further, the upper surface of the suspension plate 4 is rectangularly arranged with four first lifting rings 10, and the first lifting rings 10 are respectively connected to steel wire ropes 11, and the tops of the four steel wire ropes 11 are commonly connected to a second lifting ring 12, and the second lifting ring 12 is connected to the hook of the lifting equipment.

[0056] In this embodiment, it can be understood that when the suspension plate and the linear positioning groove are in place, the above-mentioned regular tetrahedral structure is formed. In the initial state, the guide rod slides to the lowest position in the linear bearing due to gravity. At this time, the second limit block abuts against the upper end of the suspension plate. This initial position is referenced to Figure 1 , 4 As shown, a regular tetrahedron structure is also formed, so the positioning process of the present invention can be understood as a process in which the regular tetrahedron structure becomes shorter and shorter until the final shape.

[0057] Example 7

[0058] Based on the above embodiments, this embodiment discloses a method for positioning outside the borehole of a bridge bored pile precise positioning system, such as Figure 1-4 As shown, the following steps are included:

[0059] (1) Coaxially weld the positioning steel cage 14 on the top of the steel cage A13 (this step can be prefabricated in the factory), so that the first longitudinal reinforcement 15 of the positioning steel cage 14 is welded to the inside or outside of the second longitudinal reinforcement of the steel cage A13 to ensure that the steel cage A13 is coaxial with the positioning steel cage 14;

[0060] (2) The steel cage A13 is placed obliquely by a bracket (not shown) so that the guide section of each first longitudinal reinforcement 15 passes through the guide connection hole, and then the limit nut 16 is tightened. At this time, the upper and lower ends of the suspension plate 4 are coaxial with the axes of the positioning steel cage 14 and the steel cage A13, respectively, and are perpendicular to each other;

[0061] (3) The ground around the borehole 3 is leveled, and the surface positioning mechanism is lifted to the position of the steel casing 1 by a lifting device, so that the vertical tube 205 is sleeved outside the steel casing 1, and the lower part of the annular bottom plate is padded to prevent settlement when the steel cage A is lowered, and each linear positioning groove 202 is adjusted to the same height;

[0062] (4) The lifting device is connected to the second lifting ring 12, and the suspension positioning mechanism is lifted as a whole through the suspension plate 4;

[0063] (5) The lifting equipment places the steel cage A13 into the borehole 3, and makes the four rollers 9 contact the corresponding linear positioning grooves 202 respectively. Due to the effect of gravity, the bottom end of the second limit block 7 contacts the top of the suspension plate 4 at first. As the suspension plate 4 is lowered, the guide rod 6 slides upward along the linear bearing 5, and the roller 9 slides downward along the linear positioning groove 202. Finally, the roller 9 abuts against the first limit block 204, and the third limit block 8 abuts against the fourth limit block 19. At this time, the suspension plate 4 is located at the preset position and the axes of the suspension plate 4, the through hole 17, the positioning steel cage 14, and the steel cage A13 coincide with the axis of the borehole 3. The steel cage A13 is placed down to the preset depth in the borehole 3;

[0064] (6) After the cast-in-place pile is formed by inserting a guide tube through the through hole 17, the excess positioning steel cage 14 is cut off (the steel holes left in the pile play a role in strengthening the top strength of the pile), and the suspension positioning mechanism is lifted away by a lifting device. The bottom of the positioning steel cage of the cut-off steel cage is re-welded with a steel cage of the same size and structure as the cut-off steel cage, so as to be used for the next drilling positioning.

[0065] The annular bottom plate and vertical tube of the present invention are provided with various models according to the sizes of the steel casing, which can be replaced as needed. The positioning steel cage can be used repeatedly. The surface positioning mechanism and the suspension positioning mechanism can be accurately prefabricated in the factory according to the construction situation. After arriving at the construction site, fast and efficient positioning and pouring of the steel hole A can be achieved.

Claims

1. A precise positioning system for bored piles of bridges, characterized by: It includes a surface positioning mechanism and a suspension positioning mechanism, wherein the surface positioning mechanism includes four linear positioning grooves arranged on the ground where the outer periphery of the steel casing at the top of the borehole is located, the four linear positioning grooves are connected to the steel casing through the steel casing positioning mechanism and have the same slope, and the steel casing positioning mechanism makes the four linear positioning grooves evenly distributed around the axis of the borehole and the center line of the linear positioning groove is coplanar with the axis of the borehole; The suspension positioning mechanism includes a suspension plate, a guide rod, a roller, and a positioning steel cage. The top of the suspension plate is connected to the lifting equipment through a wire rope. Four guide rods are evenly distributed around the axis on the suspension plate. Rollers are provided at the bottom of the guide rods. The four rollers are used in conjunction with four linear positioning grooves respectively. The suspension plate is penetrated by a positioning steel cage in the longitudinal direction and is fixedly connected to the positioning steel cage. The bottom of the positioning steel cage is coaxially welded to the inner or outer side of the top of the steel cage A to be placed in the drilled hole, and the axis of the steel cage A coincides with the central axis of the suspension plate. When the four rollers are in place with the linear positioning grooves, the steel cage A is inserted into the set position in the drilled hole and the axis of the steel cage A coincides with the axis of the drilled hole.

2. A bridge bored pile precise positioning system as claimed in claim 1, characterized in that: A through hole is provided in the middle of the suspension plate, and the through hole is coaxially arranged with the steel cage A. The through hole is used to insert a conduit for pouring concrete to pour the steel cage placed in place.

3. A bridge bored pile precise positioning system as claimed in claim 2, characterized in that: The steel casing is coaxial with the borehole, and the top of the steel casing extends out of the ground. The steel casing positioning mechanism includes a vertical tube coaxially sleeved outside the steel casing and matching the clearance of the steel casing, and an annular bottom plate perpendicular to the axis of the vertical tube and coaxially welded to the lower end of the outer periphery of the vertical tube; The annular bottom plate is provided with a connection hole for connecting the lifting equipment, and four linear positioning grooves are distributed on the outer surface of the annular bottom plate at 90° intervals, and the bottom of the groove is inclined downward toward one side of the steel casing. The linear positioning grooves are connected to the annular bottom plate through a lifting mechanism.

4. A bridge bored pile precise positioning system as claimed in claim 3, characterized in that: The linear positioning groove is provided with a first limit block, and the four first limit blocks have the same structural shape and the same height relative to the annular bottom plate; The lifting mechanism includes four supporting legs longitudinally arranged on the side walls of the linear positioning groove, the bottom ends of the four supporting legs are fixedly connected with pads, the pads are detachably fixedly connected to the bottom plate by bolts, and the supporting legs are telescopic structures and are used to adjust the height of the linear positioning groove.

5. A bridge bored pile precise positioning system as claimed in claim 4, characterized in that: The supporting leg is a hydraulic cylinder, an electric cylinder or a pneumatic cylinder. The fixed end of the telescopic structure is fixedly connected to the side wall of the linear positioning groove, and the telescopic end is fixedly connected to the pad.

6. A bridge bored pile accurate positioning system as claimed in claim 5, characterized in that: The suspension plate is a cubic structure, and the four corners of the suspension plate are respectively provided with guide holes inclined outwards with the same inclination, and linear bearings are fixed in the guide holes; The guide rod passes through the linear bearing and slides with the linear bearing. A second limit block is provided on the top of the guide rod, and a third limit block is provided on the bottom of the guide rod near the roller. The four corners of the lower surface of the suspension plate are provided with fourth limit blocks used in conjunction with the third limit block.

7. A bridge bored pile accurate positioning system as claimed in claim 6, characterized in that: A plurality of first longitudinal bars are uniformly welded on the outer periphery of the positioning steel cage, the first longitudinal bars are welded to the inner side or outer side of the second longitudinal bars of the steel cage A, and the first longitudinal bars extend upward to form a guide section; The guide section passes through a guide connection hole which is vertically preset on the suspension plate and located at the periphery of the through hole. A threaded section is provided on the upper part of the guide section, and a limiting nut is screwed on the threaded section.

8. A bridge bored pile accurate positioning system as claimed in claim 7, characterized in that: The upper and lower end surfaces of the suspension plate are square, the four first limit blocks are consistent with the axis of the steel casing, and the upper surface of the suspension plate is rectangular with four first suspension rings arranged; The first lifting rings are respectively connected to steel wire ropes, the tops of the four steel wire ropes are commonly connected to a second lifting ring, and the second lifting ring is connected to a hook of a lifting device.

9. The method for positioning outside the borehole of the bridge bored pile accurate positioning system as claimed in claim 8, characterized in that it comprises the following steps: (1) Weld the positioning steel cage coaxially on the top of the steel cage A, so that the first longitudinal reinforcement of the positioning steel cage is welded to the inside or outside of the second longitudinal reinforcement of the steel cage A, ensuring that the steel cage A is coaxial with the positioning steel cage; (2) The steel cage A is tilted and placed by the bracket so that the guide section of each first longitudinal reinforcement passes through the guide connection hole, and then the limit nut is tightened. At this time, the upper and lower ends of the suspension plate are coaxial with the axis of the positioning steel cage and the steel cage A respectively and are perpendicular to each other; (3) The ground around the borehole is leveled, and the surface positioning mechanism is lifted to the position of the steel casing by a lifting device, so that the vertical tube is set outside the steel casing, the lower part of the annular bottom plate is padded, and each linear positioning groove is adjusted to the same height; (4) The lifting device is connected to the second lifting ring, and the suspension positioning mechanism is lifted as a whole through the suspension plate; (5) The lifting equipment places the steel cage A into the drill hole, and makes the four rollers contact with the corresponding linear positioning grooves respectively. Due to the effect of gravity, the bottom end of the second limit block contacts with the top of the suspension plate at first. As the suspension plate is lowered, the guide rod slides upward along the linear bearing and the roller slides downward along the linear positioning groove. Finally, the roller abuts against the first limit block, and the third limit block abuts against the fourth limit block. At this time, the suspension plate is located at the preset position and the axes of the suspension plate, the through hole, the positioning steel cage, and the steel cage A coincide with the axis of the drill hole. The steel cage A is placed at the preset depth in the drill hole. (6) After the guide tube is inserted through the through hole and the cast-in-place pile is formed, the excess positioning steel cage is cut off, and the suspension positioning mechanism is lifted away by the lifting equipment. The bottom of the positioning steel cage of the cut-off part of the steel cage is re-welded with a steel cage of the same size and structure as the cut-off steel cage, so as to be used for the next drilling positioning.

Images