Method for removing excess pile heads

Abstract

This invention provides a method for removing excess pile material from pile heads that significantly reduces the amount of manual crushing work using a hand breaker, thereby saving labor in pile head processing. [Solution] An edge cutting process in which a cut is made with a cutter at the top surface of the permanent pile head, A separation process in which the excess pile head is separated, leaving the portion closest to the permanent structure, A side removal step is performed to remove the outer circumference of the excess material while leaving the core inside the main reinforcement arranged in a circular shape within the excess material, A splitting step in which the core is divided into blocks that can be lifted, A lifting preparation step involves installing a lifting fitting on the aforementioned block, A removal process involves using the aforementioned lifting fittings to lift the block and moving it away from the pile head, Characterized by consisting of, This configuration was designed for removing excess pile material from the pile head.

Description

Technical Field

[0001] The present invention relates to a method for removing excess concrete at the top of a pile, which significantly reduces manual crushing work using a hand breaker and enables labor saving in pile head treatment.

Background Art

[0002] Fig. 1 shows the upper part (pile head 4) of a pile driven into the ground. As shown in Fig. 1, in a pile, a cage reinforcement 1 composed of main reinforcement bars 2 arranged vertically and hoop reinforcement bars 3 (band bars) arranged horizontally perpendicular to the main reinforcement bars is provided. At the upper part of the pile where concrete 5 is placed in the pile hole, there is what is called "excess concrete 7", which is a solidified mass formed by impurities such as slime and sludge mixed in the flowing concrete 5 floating and gathering. It is a necessary part to ensure the quality and strength of the buried pile (original installation 6), and it is removed after the pile is solidified. The removal of excess concrete 7 and the treatment of the top surface of the original installation 6 are called pile head treatment (Non-Patent Document 1). In large-scale buildings, the pile diameter is generally 2 m or more, and the height of the excess concrete is generally in the range of 0.5 m to 3 m.

[0003] As pile head treatment, as described in Non-Patent Document 1, the periphery of the lower part of the excess concrete is cut with a cutter, and manual crushing (chopping with a hand breaker or the like, separating the excess concrete part using solidification expansion of a liquid, core extraction method of pulling out with a crane (Non-Patent Document 2), static crushing method (crack induction by energization or chemical agent), etc.) is carried out.

[0004] The method of Non-Patent Document 2 is convenient for peeling the excess concrete from the main reinforcement bars and easily pulling it out. However, in foundation work, in most cases, the area is wide and the crane arm cannot reach, or the lifting weight exceeds the limit, so large cranes cannot be used for pile heads.

[0005] Normally, cloth (covering 2a) is wound around the upper part of the main reinforcement bar 2 and the part located in the excess concrete 7, mainly for protecting the main reinforcement bar from damage during chopping and preventing rust due to the exposure of the main reinforcement bar after removing the excess concrete for curing.

Prior Art Documents

[0006] [Non-Patent Document 1] https: / / www.rise-jms.jp / media / kensetsu_yougo / a764 [Non-Patent Document 2] https: / / www.toda.co.jp / news / 2023 / 20230925_003260.html [Overview of the project] [Problems that the invention aims to solve]

[0007] Therefore, the objective is to provide a method for removing excess pile material from pile heads that significantly reduces the manual crushing work using a hand breaker, thereby saving labor in pile head processing. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention (1) The process involves cutting an incision with a cutter at the top surface of the permanent pile head, Excess pile head from Part close to the main unit Lower excess material Leaving Upper excess The separation process, A side removal step is performed to remove the outer circumference of the excess material while leaving the core inside the main reinforcement arranged in a circular shape within the excess material, A splitting step in which the core is divided into blocks that can be lifted, A lifting preparation step involves installing a lifting fitting on the aforementioned block, A removal process involves using the aforementioned lifting fittings to lift the block and moving it away from the pile head, It consists of, The block that is first separated from the core has an easily liftable shape that becomes smaller from top to bottom, and the lifting is straight up. Characterized by, Method for removing excess pile head. ( 2 ) The aforementioned easy-lifting shape is the aforementioned UpperDrill holes obliquely with respect to the vertical of the surplus, and insert a packer into the drilled holes and split them to form, characterized in that,( 1 ) The method for removing the surplus of the pile head described in ( 3 ) The oblique direction is such that the inclination angle between the vertical and the upper part of the surplus is in the range of 10° to 40°, characterized in that,( 2 ) The method for removing the surplus of the pile head described in ( 4 ) Next to the separation step, there is a splitting step of splitting the surplus into two or more stages to a height of about 40 cm to 100 cm, In the aforementioned division process Sep Divide The Most Upper step ​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​The method for removing surplus of pile head according to (1), characterized in that the position of the first block lifted from the core is at the end or the center of the side of the core. ( 9 ) When a cross H shape is provided as a structural column in the center of the pile head steel , The method for removing surplus of pile head according to (1), characterized in that the position of the first block lifted from the core is the cross H shape Steel measuring plane. ( 10 ) The method for removing surplus of pile head according to ([ 5 ), characterized in that it includes a separation step of recovering the suspension fitting after the loading step. ( 11 ) The method for removing surplus of pile head according to (1), characterized in that the lifting is carried out by a mini Hydraulic excavator or a small crane Alternatively, one of the chain blocks to be selected. . ( 12 ) A splitting step of splitting the core of the surplus of the pile head into blocks that can be lifted, A lifting preparation step of installing a suspension fitting on the block, An unloading step of lifting the block using the suspension fitting and moving it from the pile head, which consists of The block that is first separated from the core has an easy-to-lift shape that becomes smaller from top to bottom, and the lifting is directly above. and is characterized by a method for removing surplus of pile head. configured as.

Advantages of the Invention

[0009] Since the present invention has the above configuration, the following effects are achieved. That is, stake When removing the surplus of the pile head, it is possible to significantly reduce the manual crushing work by a hand breaker and provide a method for removing the surplus of the pile head that can save labor in pile head processing. More specifically, by dividing the pile head into large sections and lifting them in sections using a hoisting machine, the process can be completed with approximately half the number of workers compared to the conventional manual pile head treatment using hand breakers. This doubles the work efficiency and significantly shortens the construction period. This also reduces the burden of securing workers, which is a serious labor shortage that is commonplace in the construction industry. Furthermore, since the chipping process can be significantly reduced, it contributes to preventing vibration-related injuries and noise. In addition, it reduces the amount of damage caused by the chisel tip to the main reinforcement and structural columns during hand breaker work. [Brief explanation of the drawing]

[0010] [Figure 1] This is a partial perspective view illustrating a pile head 4 in the case where a structural column is not provided in the center of the inside of the pile head, and the excess reinforcement 7 is approximately 1 m high and approximately 2.8 m in diameter. Concrete 5 is shown by a dotted line, and the dashed line is a cut 6a at the location that will be the top surface of the main structure 6. The dashed line indicates the separation position within the excess reinforcement 7 (separation position of the upper excess reinforcement 7i and the lower excess reinforcement 7k in the excess reinforcement 7, and separation position of the upper excess reinforcement 7m and the lower excess reinforcement 7n in the upper excess reinforcement 7i). The main reinforcement 2 of the cage reinforcement 1 and its covering 2a are shown in different shades to make it easier to distinguish between the front and back. [Figure 2] Figure 1 is a schematic plan view of the pile head. The dashed line indicates the target reinforcement shape (center 7c) to be left inside the main reinforcement after the side removal process. [Figure 3] This is a schematic plan view illustrating the procedure for removing the side portion that forms the core 7c when a structural column is not provided in the center of the pile head. [Figure 4] Figure 3 is a schematic plan view of the pile head after the side removal process. [Figure 5] This is a schematic plan view illustrating the procedure for the splitting process that divides the material into liftable blocks, as shown in Figure 4. Note that the borehole 7a during the formation of the core 7c is not shown, and the area below the separation surface 7d is omitted. [Figure 6] Figure 5 is an explanatory diagram of the lifting preparation process and the unloading process in the case shown. [Figure 7] This is a schematic plan view of the pile head after the side removal process, when a square column is provided as a structural column in the center of the pile head. [Figure 8] This is a schematic plan view illustrating the procedure for the splitting process that divides the material into liftable blocks, as shown in Figure 7. [Figure 9] This is a schematic plan view illustrating the second step of the splitting process, which divides the material into liftable blocks, as shown in Figure 7. [Figure 10] This is a schematic plan view illustrating the third step of the splitting process, which divides the material into liftable blocks, as shown in Figure 7. [Figure 11] This is a schematic plan view of the pile head after the side removal process, when an H-shaped steel beam is installed as a structural column in the center of the pile head. [Figure 12] This is a schematic plan view illustrating the procedure for the splitting process that divides the material into liftable blocks, as shown in Figure 11. [Figure 13] This is a schematic plan view illustrating the second step of the splitting process, which divides the material into liftable blocks, as shown in Figure 11. [Modes for carrying out the invention]

[0011] The embodiments of the present invention will be described in detail below with reference to the attached drawings. However, the present invention is not limited to the embodiments described below. [Examples]

[0012] The method for removing excess pile head material consists of an edge cutting process, a separation process, a side removal process, a splitting process, a lifting preparation process, and a transport process. A top surface treatment process is performed as the final step in the pile head treatment.

[0013] As shown in Figure 1, the edge-cutting process involves first making an incision with a diamond cutter or similar tool at the top surface of the main pile 6 at the pile head 4, thereby cutting off the edge to prevent cracks from forming in the main pile 6 during the removal of the excess pile 7.

[0014] The separation process is a conventional procedure in which the excess pile 7 at the pile head 4 is separated, leaving the portion closest to the main pile 6. This involves drilling a hole approximately 10 cm away from the top surface of the main pile 6, then inserting a wedge and a packer into the drilled hole 7a to split it, thereby separating the excess pile 7 above the drilled hole 7a from the main pile 6. The number of drilled holes 7a is selected appropriately according to the pile diameter. For a pile with a diameter of 2.8 m, 8 to 16 drilled holes 7a (drill bit diameter 40 mm) are drilled, packers are placed at 90° intervals in 4 locations, and wedges are driven into the other drilled holes 7a to split them, causing cracks to run horizontally and separating the upper part of the excess pile 7. In Figure 1, only the three drilled holes 7a in the foreground are shown, and the other drilled holes 7a are not shown.

[0015] The height of the retaining wall 7 should be divided into two or more sections of approximately 40cm to 100cm in height, either before or after the separation process, taking into account the pile diameter. The divided retaining wall 7 should be lower when the pile diameter is large and higher when the pile diameter is small for better work efficiency. For example, dividing it to approximately 40cm when the pile diameter is 3m and to approximately 100cm when the pile diameter is 2m will further improve the efficiency of splitting and removal.

[0016] The side removal process is a process of removing the outer layer of the retaining wall 7 so as shown in Figures 1-4, that the core 7c remains inside the main reinforcement bars 2 which are arranged in a circular pattern inside the retaining wall 7. The formation of the core 7c when there is no structural column in the center inside the retaining wall 7 will be explained below.

[0017] Figure 2 is a schematic plan view of the pile head 4 corresponding to Figure 1. The thickness (skin) from the main reinforcement 2 to the side of the pile head is approximately 15 cm. The dotted line shows the ideal core 7c shape (polygonal shape) that remains inside the main reinforcement 2 which is arranged in a circular pattern inside the retaining wall 7. The area outside the core 7c is the outer perimeter of the retaining wall 7, which is removed manually using a hand breaker or similar tool.

[0018] As shown in Figure 3, first, several holes 7a are drilled at locations corresponding to the sides of the core 7c, and each side is split. Splitting is done by inserting a packer P into the drilled hole 7a and driving a wedge ▼ into the remaining space, splitting into a rectangle shown by the solid line. For a pile with a diameter of 2.8m, drilling 2 to 4 holes 7a (drill bit diameter 40mm) on one side and splitting with packer P at 1 or 2 locations on one side will cause cracks to enter downwards, splitting down to the bottom of the excess pile 7 of the working section. As an example, in Figure 3, two inner locations on one side are used as packers P, and both ends are used as wedges ▼. The distance between drilled holes 7a should be changed as appropriate depending on the pile diameter and the number of drilled holes 7a, but it should be approximately 20cm.

[0019] Subsequently, the excess material (diagonal hatching) on ​​the outside of the square-shaped split is removed by conventional manual chipping using a hand breaker or similar tool. Furthermore, the excess material (horizontal hatching) at the corners of the square, including the main reinforcement bars 2, is removed using drilling holes 7a, packers P, and / or a hand breaker to form the ideal core 7c shape shown by the dotted line. As a result, the core 7c with the plan view shape shown in Figure 4 is formed. By ensuring the core 7c is as large as possible, the amount of manual chipping work required to remove the excess material on the outside of the core 7c can be minimized.

[0020] The splitting process is the process of dividing the core 7c into liftable blocks 8. As shown in Figure 5, the blockization of the core 7c in the case where a structural column is not provided in the center of the excess timber 7 will be explained. In Figure 5, the parts that have already been split are shown by solid and dotted lines. The dashed lines indicate the locations where splitting will be performed later.

[0021] The core 7c is first split vertically and horizontally in the height direction when viewed from above, dividing the core 7c into liftable blocks 8. Splitting is mainly performed by inserting and operating a packer into the borehole 7a. After splitting the core 7c vertically or horizontally in the height direction from above, the blocks 8 may be cut out one by one, or the blocks 8 may be formed by splitting vertically and horizontally. In Figures 5 and 6, the blocks 8 are cut out one by one after being split vertically (up and down direction in the drawing).

[0022] If block 8 is to be removed by lifting it straight up, the block 8 that is first separated from the core should have an easy-to-lift shape that becomes smaller from top to bottom. Because the block is cut by splitting, the split surface is not flat, and irregularities are formed. If these irregularities interlock, they will get caught when lifting in the straight direction, and the work will not be carried out smoothly.

[0023] The easily liftable block 8 can be formed by drilling a hole at an angle to the vertical of the retaining wall 7 with a rock drill, inserting a packer into the hole, and splitting it (split block 8 in the lower left of Figure 5). The angled hole 7a should have an inclination angle 7f between the vertical 7e of the retaining wall 7 and the top of the hole in the range of 10° to 40°. If the inclination angle 7f is narrower than 10°, the irregularities may interlock and prevent lifting, and it is difficult to control the inclination angle 7f of the hole 7a within that range. On the other hand, if the inclination angle 7f is greater than 40°, it is difficult to drill the hole 7a.

[0024] If the first block 8 to be separated and lifted from the core 7c is located at the edge of the core 7c, the blocks 8 can be easily lifted straight up without interlocking with each other. Although this increases the number of drilling and splitting steps, it is also possible to split, cut out, and lift an easily liftable block 8 at the center of the edge of the core 7c.

[0025] The size (weight) of the block depends on the load capacity of the lifting device, but mini Hydraulic excavator When lifting with a mini backhoe or small crane, the lifting capacity of a mini hydraulic excavator is approximately 0.8 tons, and the specific gravity of concrete is 2.5 tons / m³. 3 Therefore, if the block has a height (H) of 50 cm, a length (D) of 70 cm, and a width (W) of 70 cm, the block will weigh approximately 0.6 tons. Here, mini hydraulic excavators and small cranes refer to machines with a weight range of approximately 3 tons to 5 tons. Hydraulic excavator This method is faster and more efficient.

[0026] The lifting preparation process, as shown in Figure 5, involves installing lifting hardware 9 on the blocks 8 that were divided in the splitting process. Lifting hardware 9 includes anchors, eye bolts, and hook bolts that can be fixed to concrete and are available on the market, with some having a load capacity of 1 ton. Once the blocks 8 have been moved and loaded, the lifting hardware can be easily separated from the concrete by chipping away at it (separation process).

[0027] The removal process, as shown in Figure 6, involves lifting the block 8 using the lifting bracket 9 and moving it away from the pile head 4. Since the block 8 is located inside the main reinforcement 2, it will be lifted and removed. The lifting method will be a mini lifting device that can be moved at the pile head treatment site. Hydraulic excavator This includes small cranes and chain blocks. Block 8 is ultimately loaded onto vehicles for transport from the construction site. By transporting the material in the Block 8 form, the number of workers can be reduced and the construction period can be significantly shortened compared to the conventional method of crushing the material into fine rubble, which is then manually transported and loaded onto vehicles.

[0028] After the removal of the separated excess pile 7 is complete, the remaining excess pile 7 near the main structure is chipped away with a hand breaker up to the top surface of the main structure, and the top surface treatment process to form the top surface of the main structure 6 is performed, thereby completing the pile head treatment. [Examples]

[0029] Next, referring to Figures 7-10, the procedure for dividing the block 8 from the core 7g when a square column 10 is provided as a structural column in the center of the pile head 4a will be explained.

[0030] Figure 7 shows a schematic plan view of the pile head after the side removal process, in which a square column 10 is provided as a structural column in the center of the inside of the pile head 4a. Except for the presence of the square column 10, the core 7g is formed through the edge cutting process, separation process, and side removal process, similar to the case in Example 1 where a structural column is not provided in the center of the inside of the pile head 4.

[0031] In Figure 7, solid and dotted lines indicate areas that have already been split and drilled, while dashed lines indicate areas that will be split and drilled later. After the division of block 8, the lifting equipment 9 is installed in the lifting preparation process, and the block 8 is lifted using the lifting equipment 9 and moved from the pile head 4a in the removal process, similar to Example 1. These steps are the same in Example 3.

[0032] In Figure 8, the easily liftable block 8(a) is divided by inserting a packer into holes drilled at an oblique angle 7f on two perpendicular sides in the lower left of Figure 8, where the core 7g is located. Subsequently, in Figure 8, the block is cut out from the right of block 8 in one direction (indicated by the dashed arrow) in a counterclockwise direction.

[0033] In Figure 9, the easily suspendable block 8(a) is divided by inserting a packer into a hole drilled at an oblique angle 7f from the left and right sides toward the center downwards, in the center of the edge of the core 7g. The contact surface with the rectangular prism 10 is easily separated. Subsequently, in Figure 9, the block is cut out from the right of block 8 in one direction (dotted arrow) in a counterclockwise direction.

[0034] In Figure 10, the easily liftable block 8(a) is divided, similar to Figure 9, by inserting a packer into a hole drilled at an oblique angle of 7f from the left and right sides toward the center downwards at the center of the edge 7g. Subsequently, in Figure 10, blocks are cut out from the left and right sides of block 8(a) toward the top (a→b→→c). Since it is possible to divide the block in two directions simultaneously (indicated by the dashed arrows), the construction period can be shortened. [Examples]

[0035] Using Figures 11 to 13, a cross H-shaped structural column is placed in the center of the interior of pile head 4b. steel The procedure for dividing block 8 from core 7h when 11 is present is described below.

[0036] Figure 11 shows a cross H-shaped structural column in the center of the inside of pile head 4b. steel A schematic plan view of the pile head after the side removal process when 11 is provided is shown. Cross H type steelExcept for the presence of 11, the core 7h is formed through an edge cutting process, a separation process, and a side removal process, similar to the case in Example 1 where a structural column is not provided in the center of the pile head 4.

[0037] In Figure 12, the easily lifted block 8(a) is the core 7 h The central part of the side and a cross H shape steel 11 side surface 11a Then, a packer is inserted into a slanted hole drilled from the left and right towards the center downwards, with an angle of 7f, to divide it. Cross H-shape steel Since section 11 is filled with concrete 5 (diagonal hatching), the first section to be separated and lifted is a cross H shape. steel 11 side surface 11a Let's assume that.

[0038] Subsequently, in Figure 12, cut out the block from the right of block 8 in one direction counterclockwise (indicated by the dashed arrow). Of course, you can also cut out the block from the left of block 8 in one direction clockwise. Note that this is a cross H shape. steel The concrete 5 filled inside 11 is removed by manual chipping.

[0039] In Figure 13, the easily lifted block 8(a) is, as in Figure 12, center 7 h The central part of the side and a cross H shape steel 11 side surface 11a Then, a packer is inserted into a slanted hole drilled from the left and right sides toward the center downwards, with an angle of 7f, and the block is divided. After that, in Figure 13, the block is cut out from the left and right sides toward the top (a→b→→c). At the same time, the block is divided in two directions (dotted arrows). , lifting Because this is possible, The method in Figure 12 involves further blocking and lifting. This allows for a shorter construction period.

[0040] 1 Basket Straight 2 Main reinforcement 2a Covering 3. Hoop muscles 4 Pile head 4a Pile head 4b Pile head 5. Concrete 6 Main installation 6a Notch 7 Yumori 7a Drilling 7b Crack 7c core 7d separation plane 7e vertical 7f tilt angle 7g core 7h core 7i Upper side excess 7k Lower side excess 7m Top tier leftovers 7n Leftovers in the bottom tier 8 blocks 9 Hanging hardware Decagonal prism 11 Cross H-shape steel 11a side

Claims

1. The process involves cutting an incision with a cutter at the top surface of the permanent pile head, A separation process in which the excess pile head is separated, leaving the portion closest to the permanent structure, A side removal step is performed to remove the outer circumference of the excess material while leaving the core inside the main reinforcement arranged in a circular shape within the excess material, A splitting step in which the core is divided into blocks that can be lifted, A lifting preparation step involves installing a lifting fitting on the aforementioned block, A removal process involves using the aforementioned lifting fittings to lift the block and moving it away from the pile head, Characterized by consisting of, Method for removing excess pile head.

2. The method for removing excess pile head material according to claim 1, characterized in that the block initially separated from the core has an easily liftable shape that becomes smaller from top to bottom, and the lifting is straight up.

3. The method for removing excess pile head material according to claim 2, characterized in that the easy-lift shape is formed by drilling a hole at an angle to the vertical of the excess pile with a drilling machine, and then inserting a packer into the hole and splitting it.

4. The method for removing excess pile head material according to claim 3, characterized in that the angle of inclination between the vertical and upper part of the excess pile is in the range of 10° to 40°.

5. The separation step is followed by a division step in which the excess material is divided into two or more layers with a height of approximately 40 cm to 100 cm. A method for removing excess pile head from a pile head according to claim 1, characterized in that the side removal step, the splitting step, the lifting preparation step, and the transport step are performed from the separated upper excess pile.

6. The method for removing excess pile head material according to claim 1, characterized in that the movement of the block in the transport process includes a loading process of placing it on a vehicle.

7. The method for removing excess pile head from a pile head according to claim 1, further comprising a top surface treatment step of chipping away the remaining excess pile near the main structure with a hand breaker up to the top surface of the main structure after the removal of the separated excess pile is completed, thereby forming the top surface of the main structure.

8. If a structural column is not provided in the center of the pile head, The method for removing excess pile head from a pile head according to claim 1, characterized in that the position of the first block to be lifted from the core is the end of the core.

9. When a square column is provided as a structural column in the center of the pile head, The method for removing excess pile head from a pile head according to claim 1, characterized in that the position of the first block to be lifted from the core is at the end or the center of the side of the core.

10. When a cross H-shaped rope is provided as a structural column in the center of the pile head, The method for removing excess pile head material according to claim 1, characterized in that the position of the first block to be lifted from the core is the cross H-shaped steel surface.

11. The method for removing excess pile head material according to claim 6, further comprising a sorting step of recovering the lifting fittings after the loading step.

12. The method for removing excess pile head material according to claim 1, characterized in that the lifting is performed by a mini excavator or a small crane.

13. The method for removing excess pile head from a pile head according to claim 1, characterized in that the lifting is performed by a chain block.

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