Separating type bored pile steel casing

Abstract

The utility model relates to a separated type bored pile steel casing which comprises a pair of split type casing bodies which are coaxially arranged, an annular space is arranged at the end of one split type casing body, and the other split type casing body is connected to the annular space in an inserted mode and abuts against the end wall and at least one peripheral wall of the annular space. The circumferential outer wall of the lower split pile casing is provided with an annular steel bar, the circumferential outer wall of the upper split pile casing is slidably connected with at least two hanging bars, the circumferential inner wall of the upper split pile casing is coated with an anti-sticking layer, the bottom ends of the hanging bars are arranged on the annular steel bar, and the anti-sticking layer is arranged close to the annular space. According to the utility model, the pair of split pile casings are buckled to form a complete chair cover steel pile casing buckling system, and the lifting hook and the bonding layer are supplemented, so that the operations of hoisting the steel pile casings, adjusting the postures of the split pile casings, pulling out the split pile casings positioned above and the like are facilitated, the construction efficiency is improved, and the construction cost is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of steel casings, in particular to a separated bored pile steel casing. Background Art

[0002] Steel casing is used to protect the bored piles in the process of manual bored pile construction. Due to the instability of the soil, it is difficult to construct reinforced concrete retaining walls, so steel retaining walls are used to protect the bored piles to prevent the collapse of the holes and avoid affecting the construction progress and safety. The Shaojiadu Yuyao River Bridge project has two main piers in the Yuyao River, with a total of 136 1.5m bored piles. The height of the pile top from the water surface is about 10m. Considering the buried depth of the steel casing under the riverbed and the structure of the drilling platform, a single bored pile needs to be invested with a steel casing with an inner diameter of 1750mm, a wall thickness of 12mm, a length of 17m, and a weight of about 8.9t. According to the traditional bored pile construction process, 136 steel casings need to be invested at one time, and the steel weighs about 1200t. In order to reduce the burden of one-time investment in construction, it is urgent to design a recyclable split steel casing structure.

[0003] A Chinese patent with authorization announcement number CN206956723U discloses a split steel casing structure for pile foundations, including a permanent casing, a circulating casing is arranged above the permanent casing, a circle of positioning platforms and a plurality of lower connecting ear plates are arranged on the outer wall of the top of the permanent casing from top to bottom, an upper connecting ear plate is arranged on the outer wall of the top of the circulating casing, and a plurality of pairs of connecting ear plates are formed which are aligned in the upper and lower positions, each pair of connecting ear plates is provided with coaxial through holes, a connecting bolt is passed through the through hole of each pair of connecting ear plates, and both ends of the connecting bolt are locked by nuts, thereby connecting the circulating casing and the permanent casing together.

[0004] The above-mentioned prior art solutions have the following defects: after the construction of the above-mentioned split steel casing structure is completed, the circulating casing needs to be separated from the permanent casing by unscrewing the bolts. A single steel casing uses a large number of bolts, and the installation height of the connecting bolts is not conducive to workers' operations, resulting in the installation and removal process of the circulating casing being time-consuming and laborious, which needs to be improved. Utility Model Content

[0005] The problem to be solved by the utility model is to provide a separate bored pile steel casing for the above-mentioned deficiencies in the prior art, which has the advantage of being easy to hoist and install.

[0006] The above utility model object of the utility model is achieved through the following technical solutions:

[0007] A separated bored pile steel casing comprises a pair of coaxially arranged split casings, wherein an annular space is provided at the end of one of the split casings, and the other split casing is inserted into the annular space and abuts against the end wall and at least one circumferential wall of the annular space; the circumferential outer wall of the split casing located at the bottom is provided with annular steel bars, the circumferential outer wall of the split casing located at the top is slidably connected with at least two hanging bars, and the circumferential inner wall is coated with an anti-sticking layer, the bottom end of the hanging bar is provided on the annular steel bars, and the anti-sticking layer is arranged close to the annular space.

[0008] By adopting the above technical scheme, firstly, a circular steel casing is selected for the split casing. After one of the split casings (the length is generally within 3m) is completely buried in the water, the other split casing (the burial depth in the soil is generally within 3m and the length is generally within 6m) is buckled on the above split casing, and the end sealing surface and the circumferential sealing surface are formed through the mutual cooperation between the annular space and the end of the split casing, thereby forming a complete set of steel casing buckle system, which can not only ensure that the buckling structure at the annular space is not easy to deform, but also realize the function of "overall sinking, separation and removal", and can also isolate the soil and water outside the pile hole from the mud in the pile hole to form a stable drilling environment; secondly, at least two A20 hanging rods are arranged around the circumference of the split casing, the lower end of the hanging rod is welded to the annular steel bar, and the upper end extends above the split casing located above and has a hook, and the extended section is slidably connected with the split casing located above, to ensure that the hanging rod will not be deviated during use, and the hanging rod will be in the process of driving the split casing. It plays the role of hoisting the entire steel casing. If the casing sinks or tilts during its installation, the casing posture can be adjusted by pulling out the lifting rod. If the entire casing is seriously deviated after installation, the entire casing can be pulled out and re-installed by the lifting rod. At the same time, annular steel bars are arranged at the lower part of the lifting rod to ensure that the influence of soil friction on the split casing can be reduced when the entire steel casing sinks, thereby helping the entire steel casing to sink. Thirdly, an anti-sticking layer is coated above the joint formed between the annular space and the end of the split casing to form an isolation membrane between the bored pile and the split casing located above, which can improve the success rate of pulling out the split casing located above. In this process, a complete chair cover steel casing buckle system is formed by buckling the pair of split casings to ensure that the water pressure inside and outside the steel casing socket system is balanced with the mud pressure and improve the stability of the mud liquid surface. It is assisted by a hook and an adhesive layer to facilitate the hoisting of the steel casing, the adjustment of the posture of the split casing, the removal of the split casing located above, and other operations, which is conducive to improving construction efficiency and reducing construction costs.

[0009] The utility model is further configured as follows: one of the split casings includes an anti-vibration rod group, a tool casing, a pad group and a bottom reinforcement sleeve which are sequentially sleeved and fixed from the inside to the outside, the anti-vibration rod group includes a plurality of anti-vibration rods arranged along the circumference of the tool casing, the pad group includes a plurality of pads arranged along the axial direction of the tool casing, the ends of the anti-vibration rod group and the bottom reinforcement sleeve extend to the outside of the tool casing to form the annular space; the other split casing includes a fixed casing inserted into the annular space, the fixed casing abuts against the end wall of the tool casing and the surface of the anti-vibration rod.

[0010] By adopting the above technical scheme, firstly, the anti-vibration rods are made of A28 steel bars, which are installed at least one every 45° in a circumferential manner on the inner side of the connection between the tool casing and the fixed casing, welded to the tool casing at the top and cantilevered at the bottom; the bottom reinforcement sleeve is made of Q235B steel plate with a wall thickness of 10mm. In order to increase the coordination of splicing with other fixed casings after the tool casing is removed, the inner diameter of the bottom reinforcement sleeve is 10mm larger than the outer diameter of the casing; in the process of vibration and sinking of the steel casing, the anti-vibration rods and the bottom reinforcement sleeve "clamp" the fixed casing together to ensure that it will not deviate by more than 20mm. In the process of removing the tool casing, the anti-vibration rods and the bottom reinforcement sleeve can "not clamp" the fixed casing together to ensure that it can be pulled out smoothly; secondly, circumferential pads are respectively arranged at the upper and lower ends of the overlap range of the bottom reinforcement sleeve and the tool casing to enhance the rigidity of the connection at the bottom reinforcement sleeve.

[0011] The utility model is further configured as follows: a pad away from the fixed casing is welded and fixed to the circumferential outer wall of the tool casing and the end wall of the bottom reinforcement sleeve, and the remaining pads are welded and fixed to the circumferential outer wall of the tool casing and the circumferential inner wall of the bottom reinforcement sleeve.

[0012] By adopting the above technical solution, the pads and the upper ends of the bottom reinforcement sleeves away from the fixed casing are welded to the outer periphery of the tool casing through circumferential fillet welds, and the remaining pads are arranged slightly higher than the lower section of the tool casing, reserving sufficient weld space, and then connected to the outside of the tool casing through the butt welds between the tool casing and the bottom reinforcement sleeve. The welding surface of the butt weld should be flat and must not be higher than the lower section of the tool casing to ensure that there will be no deformation, dislocation, or jamming during the sinking of the steel casing.

[0013] The utility model is further configured as follows: the annular steel bar is arranged on the fixed casing, and at least two groups of positioning buckles are arranged on the tool casing, and the hanging bars are respectively slid through these groups of positioning buckles and then fixed on the annular steel bar.

[0014] By adopting the above technical solution, the lower end of the hanger is welded to the fixed casing, the upper end extends above the tool casing and is provided with a hook, and positioning buckles are provided at intervals on the extended line section to ensure that the hanger will not be displaced during use.

[0015] The present utility model is further configured such that: the positive projection of the positioning buckle in the vertical direction is in a C shape.

[0016] By adopting the above technical solution, the positioning buckle is bent into a C shape by using at least C16 steel bars, and one is arranged every 3 m on the outer side of the tool cylinder, so that the suspension bars passing through the positioning buckle will not be misaligned.

[0017] The present utility model is further configured such that: a U-shaped bending portion protrudes outward from the middle of the suspension bar, and the U-shaped bending portion is sleeved on the bottom cylinder reinforcing sleeve with a gap.

[0018] By adopting the above technical solution, it is beneficial to strengthen the limiting effect.

[0019] The present utility model is further configured such that: the top end of the split casing located above is sleeved or embedded with a top cylinder reinforcing sleeve.

[0020] By adopting the above technical solution, the top of the tool casing directly bears the strong exciting force of the vibrating hammer. In order to avoid deformation and damage of the steel casing during vibration sinking and extraction, a steel sleeve ring with a thickness of at least 10 mm is welded again within the range of 300 mm height from the top of the casing, that is, the top cylinder reinforcing sleeve, to increase its stiffness.

[0021] The present utility model is further configured such that: the anti-adhesion layer is formed by coating formwork paint or other oily coatings.

[0022] By adopting the above technical solution, in order to ensure that the tool casing can be extracted more smoothly, an anti-adhesion layer is applied to the range of 1 m at the lower end of the tool casing and the connection part to form an isolation film between the bored cast-in-place pile and the tool casing.

[0023] The present utility model is further configured such that: a pair of split casings are arranged with acoustic wave detection tubes, and the acoustic wave detection tubes are used to cooperate with the reinforcement cage of the bored pile.

[0024] By adopting the above technical solution, the acoustic wave detection tube is a pipeline for detecting the integrity of the bored cast-in-place pile shaft, so its length is at least the pile length. Considering that the tool casing needs to be extracted before the excavation of the bearing platform, the ultrasonic detection of the pile shaft needs to be completed before the casing is extracted. Therefore, the length of the acoustic wave detection tube is at least the distance from the bottom of the bored cast-in-place pile to the water surface or the ground. The acoustic wave detection tube is usually a steel pipe with a diameter of 50 mm, and it is tied to the main reinforcement cage and the secondary reinforcement cage with iron wires.

[0025] The present utility model is further configured such that: a pair of split casings are arranged with liquid level sensors, and the detection ends of the liquid level sensors are used to cooperate with the top end of the bored pile.

[0026] By adopting the above technical solution, since the gripping force between the steel casing and the bored cast-in-place pile is very strong, in order to ensure the smooth extraction of the tool casing, it is necessary to strictly control the height of the concrete pouring liquid level of the bored cast-in-place pile. When using the liquid level sensor, it is tied to the auxiliary steel cage with iron wire. When the concrete pouring liquid level of the bored cast-in-place pile reaches 500 mm below the socket connection, an alarm is given. At this time, the pouring of concrete is stopped, the liquid level sensor is taken out and washed clean for repeated use.

[0027] In summary, the beneficial technical effects of the present utility model are as follows: By buckling these two split casings to form a complete chair sleeve steel casing buckling system, it ensures the balance of the internal and external water pressures and mud pressures of the steel casing socket system and improves the stability of the mud liquid level. Supplementary with a lifting hook and an adhesive layer, it facilitates operations such as the hoisting of the steel casing, the attitude adjustment of the split casings, and the extraction of the upper split casing, which is beneficial to improving construction efficiency and reducing construction costs. Brief Description of the Drawings

[0028] Figure 1 is a schematic structural diagram of the split bored pile steel casing of the present utility model.

[0029] Figure 2 is a schematic cross-sectional structural diagram of the split bored pile steel casing of the present utility model.

[0030] Figure 3 is a schematic connection relationship diagram among the tool casing, the backing plate group, the bottom casing reinforcement sleeve, and the fixed casing of the present utility model.

[0031] In the figure, 1. vibration-resistant rod; 2. tool casing; 3. backing plate; 4. bottom casing reinforcement sleeve; 5. top casing reinforcement sleeve; 6. annular space; 7. fixed casing; 8. circumferential steel bar; 9. suspension bar; 91. U-shaped bending part; 10. anti-adhesion layer; 11. positioning buckle; 12. sonic detection tube; 13. liquid level sensor. Detailed Embodiment

[0032] In order to make the technical means, creative features, achieved purposes, and functions realized by the present utility model clearer and easier to understand, the present utility model will be further described below in conjunction with the drawings and specific embodiments.

[0033] Refer to Figure 1 and Figure 2, a separated bored pile steel casing disclosed in the utility model, including a pair of coaxially arranged split casings, wherein an annular space 6 is provided at the end of one of the split casings, and the other split casing is plugged into the annular space 6 and contacts the end wall and circumferential inner wall of the annular space 6. The circumferential outer wall of the split casing located at the bottom is provided with an annular steel bar 8, and the circumferential outer wall of the split casing located at the top is slidably connected with two hanging rods 9, and the circumferential inner wall is coated with an anti-sticking layer 10, the bottom end of the hanging rod 9 is arranged on the annular steel bar 8, and the anti-sticking layer 10 is arranged close to the annular space 6. In this process, by buckling the pair of split casings to form a complete chair cover steel casing buckle system, it is ensured that the water pressure inside and outside the steel casing socket system is balanced with the mud pressure and the mud liquid surface stability is improved, and with the aid of a hook and an adhesive layer, it is convenient for the lifting of the steel casing, the posture adjustment of the split casing, and the removal of the split casing located at the top, which is conducive to improving construction efficiency and reducing construction costs.

[0034] Reference Figure 2 and Figure 3 First, a circular steel casing is used for the split casing. After one of the split casings (the length is generally within 3m) is completely buried in the water, the other split casing (the burial depth in the soil is generally within 3m and the length is generally within 6m) is buckled onto the above split casing, and the end sealing surface and the circumferential sealing surface are formed through the mutual cooperation between the annular space 6 and the end of the split casing, thereby forming a complete set of steel casing buckle system, which can not only ensure that the buckling structure at the exit of the annular space 6 is not easy to deform, but also realize the function of "overall sinking, separate and remove", and can also isolate the soil and water outside the pile hole from the mud in the pile hole, forming a stable drilling environment.

[0035] Specifically, one of the split casings includes a group of anti-vibration rods 1, a tool casing 2, a group of pads 3, a bottom reinforcement sleeve 4, and a top reinforcement sleeve 5 sleeved on the top of the tool casing 2. The anti-vibration rods 1 include a plurality of anti-vibration rods 1 arranged circumferentially along the tool casing 2; the pads 3 include two pads 3 arranged axially along the tool casing 2, the pads 3 away from the fixed casing 7 are welded and fixed to the circumferential outer wall of the tool casing 2 and the end wall of the bottom reinforcement sleeve 4, and the other pads 3 are welded and fixed to the circumferential outer wall of the tool casing 2 and the circumferential inner wall of the bottom reinforcement sleeve 4; the ends of the anti-vibration rods 1 and the bottom reinforcement sleeve 4 extend to the outside of the tool casing 2 and form an annular space 6. The other split casing includes a fixed casing 7 inserted into the annular space 6, and the fixed casing 7 contacts the end wall of the tool casing 2 and the surface of the anti-vibration rods 1.

[0036] The anti-vibration rod 1 is made of A28 steel bars, and is installed at least every 45° in a circumferential arrangement on the inner side of the connection between the tool casing 2 and the fixed casing 7. The upper part is welded to the tool casing 2, and the lower part is cantilevered. The bottom reinforcement sleeve 4 is made of Q235B steel plate with a wall thickness of 10mm. In order to increase the coordination of splicing with other fixed casings 7 after the tool casing 2 is removed, the inner diameter of the bottom reinforcement sleeve 4 is 10mm larger than the outer diameter of the casing. During the vibration and sinking of the steel casing, the anti-vibration rod 1 and the bottom reinforcement sleeve 4 "clamp" the fixed casing 7 together to ensure that it will not deviate more than 20mm. During the removal of the tool casing 2, the anti-vibration rod 1 and the bottom reinforcement sleeve 4 can "clamp" the fixed casing 7 together to ensure that it can be pulled out smoothly. Annular pads 3 are respectively set at the upper and lower ends of the overlap range of the bottom reinforcement sleeve 4 and the tool casing 2 to enhance the rigidity of the connection of the bottom reinforcement sleeve 4. The upper ends of the pads 3 and the bottom reinforcement sleeve 4 away from the fixed casing 7 are welded to the periphery of the tool casing 2 through circumferential fillet welds. The remaining pads 3 are arranged slightly higher than the lower section of the tool casing 2, leaving enough space for the welds, and then connected to the outside of the tool casing 2 through the butt welds between the tool casing 2 and the bottom reinforcement sleeve 4. The welding surface of the butt weld should be flat and not higher than the lower section of the tool casing 2 to ensure that there will be no deformation, dislocation, or jamming during the sinking of the steel casing. The top of the tool casing 2 directly bears the strong excitation force of the vibrating hammer. In order to prevent the steel casing from being deformed and damaged during the vibration sinking and removal, a layer of at least 10mm thick steel ring, i.e., the top reinforcement sleeve 5, is welded within a height range of 300mm from the top of the casing to increase its rigidity.

[0037] Reference Figure 1 Secondly, two A20 hanging rods 9 are arranged around the split casings. The lower end of the hanging rod 9 is welded to the annular steel bar 8, and the upper end extends above the split casing and has a hook. The extended section is slidably connected to the split casing above to ensure that the hanging rod 9 will not deviate during use. The hanging rod 9 plays a role in hoisting the entire steel casing during the installation of the split casing. If the casing sinks or tilts during the installation, the posture of the casing can be adjusted by pulling out the hanging rod 9. If the entire casing is seriously deviated after installation, the entire casing can be pulled out and reinstalled through the hanging rod 9. At the same time, annular steel bars 8 are arranged at the bottom of the hanging rod 9 to ensure that the influence of soil friction on the split casing can be reduced when the entire steel casing sinks, so as to help the entire steel casing sink.

[0038] Specifically, the circumferential steel bars 8 are arranged on the fixed casing 7. The positive projection of the positioning buckle 11 in the vertical direction is C-shaped. The positioning buckle 11 is bent into a C-shape using at least C16 steel bars, and one is arranged every 3 m on the outer side of the tool casing, which can prevent the suspension bars 9 passing through the positioning buckle 11 from being misaligned. There are two groups of positioning buckles 11 arranged on the tool casing 2. After these suspension bars 9 respectively slide through these groups of positioning buckles 11, they are fixed to the circumferential steel bars 8. A U-shaped bending part 91 protrudes outward from the middle of the suspension bar 9, and the U-shaped bending part 91 is sleeved on the bottom cylinder strengthening sleeve 4 with a gap, which is beneficial to enhancing the limiting effect.

[0039] Refer to Figure 2 Again, above the joint formed between the annular space 6 and the end of the split casing, an anti-sticking layer 10 is coated to form an isolation film between the bored pile and the split casing above, which can improve the success rate of pulling out the split casing above.

[0040] Specifically, the anti-sticking layer 10 is coated with formwork paint or other oily coatings. To ensure that the tool casing 2 can be pulled out more smoothly, the anti-sticking layer 10 is applied to the lower 1 m range and the connection part of the tool casing 2 to form an isolation film between the bored cast-in-place pile and the tool casing 2.

[0041] Finally, a sonic detection tube 12 and a liquid level sensor 13 are arranged inside the pair of split casings. Among them, the sonic detection tube 12 is used to cooperate with the steel reinforcement cage of the bored pile, and the detection end of the liquid level sensor 13 is used to cooperate with the top of the bored pile. The sonic detection tube 12 is a pipeline for detecting the integrity of the bored cast-in-place pile body, so its length is at least the pile length. Considering that the tool casing 2 needs to be pulled out before the excavation of the bearing platform, the ultrasonic detection of the pile body needs to be completed before the casing is pulled out. Therefore, the length of the sonic detection tube 12 is at least the distance from the bottom of the bored cast-in-place pile to the water surface or the ground. The sonic detection tube 12 is usually a steel pipe with a diameter of 50 mm, and it is tied to the main steel reinforcement cage and the secondary steel reinforcement cage with iron wires. Since the grip force between the steel casing and the bored cast-in-place pile is very strong, to ensure that the tool casing 2 can be pulled out smoothly, it is necessary to strictly control the height of the concrete pouring liquid level of the bored cast-in-place pile. When the liquid level sensor 13 is used, it is tied to the secondary steel reinforcement cage with iron wires. When the concrete pouring liquid level of the bored cast-in-place pile reaches 500 mm below the socket connection, an alarm is given. At this time, the concrete pouring is stopped, the liquid level sensor 13 is taken out and washed clean for repeated use.

[0042] The implementation principle of this embodiment is as follows:

[0043] (1) Precast accessories such as the fixed casing 7 and the tool casing 2 in the steel mill. After the trial assembly in the factory is correct, they are transported to the site;

[0044] (2) Weld the vibration-resistant rod 1 to the lower end of the tool casing 2, and place the fixed casing 7 flat on a flat site;

[0045] (3) Hoist the tool casing 2 onto the fixed steel casing, align and lower it, and measure the verticality of the whole set of steel casing after rough assembly. When the requirements are met, weld the hanging rod 9 and the annular steel bar 8 on the outside of the fixed casing 7 to make the fixed steel casing and the tool steel casing form a whole;

[0046] (4) Use a crane and a vibratory hammer to try to lift the entire set of steel casing. After ensuring that the entire set of steel casing is safely lifted, lift it to the bored pile position;

[0047] (5) Turn on the vibration hammer vibration mode and sink the entire set of steel casing to the specified elevation. During this process, the plane position and verticality of the steel casing should be strictly controlled;

[0048] (6) The first hole cleaning after the drilling rig has drilled into place;

[0049] (7) After the pile hole is inspected and accepted, the main steel cage and acoustic detection pipe are lowered;

[0050] (8) After the main steel cage is lowered into place, the secondary steel cage and the acoustic detection pipe are lowered and the hole is cleaned for the second time;

[0051] (9) Use the conduit method to pour underwater concrete for bored piles. During this process, turn on the concrete level sensor. When the sensor alarms, it means that the concrete of the pile body has been poured to the designed height. Remove the remaining conduits in turn. After 24 hours, clean the acoustic detection tube and punch holes.

[0052] (10) After the bored piles reach the designed strength, entrust a qualified testing agency to test the bored piles;

[0053] (11) After the pile foundation quality meets the requirements, the hanger bar 9 is cut off, and the tool casing 2 is clamped and pulled up by the crane and the vibrating hammer; the fixed casing 7 cannot be pulled out because it is stuck to the bored pile body concrete and is left in the soil;

[0054] (12) The tool casing 2 is cleaned and trimmed for ovality after being removed, and reused after meeting the requirements.

[0055] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model rather than to limit it. Although the utility model has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the technical solution of the utility model can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the utility model, which should be included in the scope of the claims of the utility model.

Claims

1. A separate bored pile steel casing, characterized in that: It includes a pair of coaxially arranged split casing pipes, where an annular space (6) is provided at the end of one split casing pipe, and the other split casing pipe is inserted into the annular space (6) and abuts against the end wall and at least one circumferential wall of the annular space (6); Circumferential steel bars (8) are provided on the outer circumferential wall of the lower split casing pipe, at least two lifting bars (9) are slidably connected to the outer circumferential wall of the upper split casing pipe, and an anti-sticking layer (10) is coated on the inner circumferential wall. The bottom ends of the lifting bars (9) are arranged on the circumferential steel bars (8), and the anti-sticking layer (10) is arranged close to the annular space (6).

2. The separated bored pile steel casing according to claim 1 is characterized by: One of the split casing pipes includes a set of anti-vibration bars (1), a tool casing (2), a set of backing plates (3), and a bottom casing reinforcement sleeve (4) that are sleeved and fixed in sequence from the inside out. The set of anti-vibration bars (1) includes a plurality of anti-vibration bars (1) arranged circumferentially along the tool casing (2). The set of backing plates (3) includes a plurality of backing plates (3) arranged axially along the tool casing (2). The ends of the set of anti-vibration bars (1) and the bottom casing reinforcement sleeve (4) extend outside the tool casing (2) and form the annular space (6). The other split casing pipe includes a fixed casing (7) inserted into the annular space (6), and the fixed casing (7) abuts against the end wall of the tool casing (2) and the surface of the anti-vibration bar (1).

3. A separate bored pile steel casing according to claim 2, characterized in that: The backing plate (3) away from the fixed casing (7) is fixedly welded between the outer circumferential wall of the tool casing (2) and the end wall of the bottom casing reinforcement sleeve (4), and the other backing plates (3) are fixedly welded between the outer circumferential wall of the tool casing (2) and the inner circumferential wall of the bottom casing reinforcement sleeve (4).

4. A separate bored pile steel casing according to claim 3, characterized in that: The circumferential steel bars (8) are arranged on the fixed casing (7), and at least two groups of positioning buckles (11) are provided on the tool casing (2). After the lifting bars (9) respectively slide through these groups of positioning buckles (11), they are fixed on the circumferential steel bars (8).

5. A separate bored pile steel casing according to claim 4, characterized in that: The positive projection of the positioning buckle (11) in the vertical direction is C-shaped.

6. A separate bored pile steel casing according to claim 4, characterized in that: A U-shaped bending portion (91) protrudes outward from the middle of the lifting bar (9), and the U-shaped bending portion (91) is sleeved on the bottom casing reinforcement sleeve (4) with a gap.

7. The separated bored pile steel casing according to claim 1 is characterized by: A top casing reinforcement sleeve (5) is sleeved or embedded at the top end of the upper split casing pipe.

8. The separated bored pile steel casing according to claim 1, characterized in that: The anti-sticking layer (10) is coated with formwork paint or other oily coatings.

9. The separated bored pile steel casing according to claim 1, characterized in that: A sonic detection tube (12) is arranged inside this pair of split casing pipes, and the sonic detection tube (12) is used to cooperate with the reinforcement cage of the bored pile for arrangement.

10. The separated bored pile steel casing according to claim 1, characterized in that: A liquid level sensor (13) is arranged inside this pair of split casing pipes, and the detection end of the liquid level sensor (13) is used to cooperate with the top end of the bored pile for arrangement.

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