JP5674582B2 - Cast-in-place concrete pile construction method and concrete recovery equipment - Google Patents

Description

  The present invention relates to a method for constructing cast-in-place concrete piles, and in particular, it is possible to construct cast-in-place concrete piles while effectively removing low-quality concrete with poor strength, which is upper concrete of cast-in concrete. It relates to a possible construction method. Furthermore, the present invention also relates to a recovery device for recovering the low-quality concrete.

  A drilling hole of the desired diameter and depth is created in the ground of the construction site, a tubular reinforcing bar made up of vertical bars (main bars) and band bars is built in the drilling hole, and a tremy pipe is placed at the center of the reinforcing bar The method of placing cast concrete by placing concrete in the excavation hole and constructing the cast-in-place concrete pile is a conventional pile construction method. This drilling hole is created mainly by the earth drill method, which is often used in construction in urban areas, the all-casing method, which is frequently used in riverbeds and mountains, and when constructing large-diameter piles at large depths. There are reverse methods applied.

  In the construction of this cast-in-place concrete pile, the formed excavation hole is filled with a stabilizing liquid such as bentonite to ensure the stability of the hole wall, and then the concrete is placed through the tremy pipe. The placed concrete is sequentially launched upward from the bottom of the excavation hole, but the concrete that has been launched to the upper part of the excavation hole is lifted by mud and mud water generated at the bottom of the pile and in the middle of the uplift The upper concrete is usually removed because it is a low quality (deteriorated) pile that does not have the desired strength.

  The upper concrete can be removed by crushing and removing low-quality concrete up to the lower position of the design length with an air compressor, breaker or hammer after hardening the concrete, or before placing the concrete and hardening it. A method of vacuuming and removing the upper part is applied.

  Regarding the former concrete removal method, Patent Document 1 discloses a method of cutting and removing pile head concrete using an earth drill-like pile head processing apparatus, and Patent Document 2 discloses a hollow body as a pile head. A method is disclosed in which a fracture pressure generator is inserted into a hollow body after the concrete is placed, and the concrete is crushed by the breaking force exerted on the hollow body. Furthermore, in Patent Document 3, a donut-shaped bag body is arranged in an expanded posture on the pile head in order to facilitate chipping of the pile head. A method of removing pile head concrete is disclosed.

  In the method of performing pile head treatment after hardening of concrete, including the removal technology disclosed in Patent Documents 1 to 3, there is a problem that the construction period is prolonged because of waiting for the concrete to harden. Noise and vibration problems that occur in In the case of a large-diameter pile, there may be a dangerous work in which an operator enters the excavation hole, performs a chiseling work, and loads a concrete glass.

  In addition, when removing the pile head concrete, the pile head rebar is damaged, and unnecessary external force is often applied to the rebar, and this external force generates internal stress that is not expected in the design. As a result, the quality of the pile can be reduced.

  On the other hand, in the case of the method of vacuum suction removal before concrete hardening rather than the method of crushing removal and chipping removal of the pile head concrete, for example, because it becomes the work of sucking the upper low quality concrete with a hose etc., It is not easy to completely remove low-quality concrete, and there is a high possibility that low-quality concrete will remain on the pile head of the applied concrete, or when the top surface of the concrete in the excavation hole is low. However, there is a problem that low quality concrete cannot be visually confirmed and the vacuum cannot be sufficiently sucked.

JP-A-4-281913 JP-A-4-333718 JP 7-97811 A

  The present invention has been made in view of the above-mentioned problems. In removing low-quality concrete that may occur at the head of a cast-in-place concrete pile, the concrete period is long without waiting for the concrete to harden. The cast-in-place concrete pile construction method that is excellent in the removal performance of low-quality concrete and that does not impart unnecessary external force to the pile head reinforcement, and the concrete applied by this construction method It aims to provide a recovery device.

  In order to achieve the above-mentioned object, the cast-in-place concrete pile construction method according to the present invention is a cast-in-place concrete pile construction method in which a reinforcing bar is built in an excavation hole and the concrete is placed to construct the cast-in-place concrete pile. A concrete collecting tool comprising a hollow cylinder body, in which a drill hole is formed, a reinforcing bar is installed in the drill hole, and the cylindrical body is provided with an insertion hole through which a vertical bar constituting the reinforcing bar is inserted And an openable and closable slit that faces the hollow, and a storage space for receiving the recovered concrete communicated with the slit is inserted into the insertion hole of the concrete recovery tool provided in the cylinder main body through the longitudinal bars of the reinforcing bar rod. A first step of installing a concrete recovery tool above; placing concrete in the excavation hole through the hollow of the concrete recovery tool; The second step of reaching the cleat, a weight is suspended in the hollow, and the concrete extruded to the hollow side by the weight is accommodated in the accommodating space via the slit of the cylinder body, and the slit is closed. By collecting the concrete collecting tool and the weight from the excavation hole in the posture, the cast-in-place concrete pile in which the upper concrete of the cast concrete is collected is constructed in a third step.

  In the construction method of the cast-in-place concrete pile according to the present invention, the excavation hole is formed, and after the reinforcing bar is built, the hollow concrete collecting tool is applied to protect the vertical bars constituting the reinforcing bar and For example, the concrete recovery tool is placed in the middle of the hollow of the concrete, the weight is suspended in this hollow before the concrete is hardened, the upper concrete is pushed into the concrete recovery tool and recovered here, and the concrete recovery tool is recovered. And it is the construction method which can collect high-quality cast-in-place concrete pile quickly and effectively collect | recovering low quality concrete of an upper part.

  In the first step, an excavation hole of a predetermined length is created at the site, and a stable bar is injected to secure the stability of the hole wall, and for example, a reinforcing bar made of vertical bars and band bars is installed. .

  Here, the construction of the excavation hole depends on the site construction status (whether the construction yard is sufficiently secured, noise and vibration tolerances, etc.), the ground properties and the pile diameter and length of the cast-in-place concrete pile to be constructed. Depending on the scale, any one of the above-described earth drill method, all-casing method, reverse method and the like can be generally applied.

  Regarding rebar rods composed of longitudinal bars and band bars, the band bars are arranged at a predetermined pitch in the length direction of the reinforcing bar rods, but there are no band bars above the reinforcing bar rods, In general, only the vertical stripes arranged in the direction at a predetermined pitch protrude.

  The concrete collecting tool is composed of a cylinder body having a hollow in the center thereof, and the cylinder body is provided with insertion holes through which the above-described vertically protruding vertical bars are inserted according to the positions of the plurality of vertical bars. The concrete collecting tool can be fixed at a predetermined level position of the vertical bar by inserting the vertical bar through the insertion hole. The concrete recovery tool can be fixed directly to the longitudinal bars, or a method of placing a anchor anchor on the hole wall of the excavation hole to stabilize the posture of the concrete recovery tool, and the concrete recovery tool to the excavation hole. A method of holding the suspended posture of the concrete collecting tool with an appropriate fixing jig from the ground while being suspended from above can be exemplified.

  In addition to the insertion hole for inserting the vertical bars, the cylinder body that constitutes the concrete recovery tool is equipped with a slit facing the hollow and low quality concrete in the upper part of the cast concrete that is in fluid communication with this slit. An accommodation space for collecting and accommodating is provided.

  Here, there are various forms of slits facing the hollow, and a form in which vertically long slits are provided at intervals in the circumferential direction on the wall surface facing the hollow of the cylinder body, or a plurality of holes are arranged at intervals in the vertical direction There may be mentioned a form in which a group of holes are provided and the hole groups are provided at intervals in the circumferential direction of the wall surface, and a plurality of slits extending in the circumferential direction are provided at intervals in the vertical direction. .

  Regardless of the type of slit, the slit is provided with a lid that can be slid in the longitudinal direction or the circumferential direction, and when the concrete is guided to the accommodation space through the slit, the slit is opened. The slit is freely openable and closable so that the concrete recovery tool can be recovered so that the closed lid closes the slit and prevents the concrete from spilling from the slit when stored in the storage space. In addition to the closed lid, if both the concrete recovery tool and the weight are recovered at the same time after the weight described later is suspended in the hollow and the weight is closed by the weight, The form which becomes a slit obstruction | occlusion means may be sufficient.

  The excavation hole is built at the site, and the reinforcing bar is built in the excavation hole in a state where the stability of the hole wall is secured with a stabilizing liquid, etc., and the vertical bar protruding above the reinforcing bar is inserted into the insertion hole. The concrete recovery tool is positioned and fixed at a predetermined level of the reinforcing bar rod (first step).

  In this first step, a method in which a concrete recovery tool is positioned and fixed in advance in the vertical bars above the reinforcing bar rods may be built when building the reinforcing rod rods in the excavation hole. .

  Next, for example, a tremy pipe is arranged in the hollow of the cylindrical body constituting the concrete recovery tool, and concrete is placed in the excavation hole.

  In this concrete placement, the cast concrete is made to reach at least the hollow middle level of the cylinder body. That is, concrete is cast up to the hollow central level or the vicinity thereof, or concrete is cast up to the vicinity of the hollow upper end level (second step). The reason for adjusting the placement level of the cast concrete in this way is that when a weight, which will be described later, is suspended in the hollow, the concrete existing in the hollow is accommodated by the weight through the slit of the cylinder body. This is to be extruded into the inside.

  After placing concrete to the desired level of hollow, a weight is suspended from the ground into the hollow of the cylinder body, and the weight sinks into the concrete in the hollow so that the upper concrete is extruded to the side of the hollow. Guided concrete is introduced into the accommodation space through the slits in the cylinder body.

  The weight is a weight having substantially the same shape as the hollow so as to loosely fit into the hollow of the cylinder body and having a weight that can sink into the concrete.

  When the weight sinks into the concrete at a predetermined level in the hollow, the concrete of the volume of the sinking weight is pushed to the side of the hollow, and the extruded concrete has a slit provided in the cylinder body. Then, it is guided to the accommodation space inside the cylinder body and collected by the concrete collecting tool.

  When the upper concrete is recovered by the concrete recovery tool, the slit is closed and the slit is closed (as described above, the weight may also serve as this cover). High-quality cast-in-place concrete in which low-quality (deteriorated) concrete (concrete containing stabilizer, latency, mud, mud, etc.) is removed by collecting the weight on the ground and hardening the concrete. A stake is constructed (third step).

  This cast-in-place concrete pile construction method does not wait for the concrete to harden and does not perform pile head treatment, so the problem of prolonged construction period due to this process is solved.

  Further, since the vertical bars constituting the reinforcing bar are protected by the concrete recovery tool and no external force is applied during the pile head processing, the problem of unexpected internal stress in the vertical bars is also solved.

  And according to the amount of low-quality concrete assumed in the construction of cast-in-place concrete piles that are the target of construction, the hollow size of the cylinder body that constitutes the concrete recovery tool and the amount of the upper concrete accommodated in this hollow It is possible to completely remove the low-quality concrete.

  Furthermore, since the pile head processing is not performed by chipping or crushing, problems such as noise and vibration cannot occur.

  Another embodiment of the cast-in-place concrete pile construction method according to the present invention is a cast-in-place concrete pile construction method in which a reinforcing bar is built in the excavation hole and the concrete is cast to construct the cast-in-place concrete pile. The first cylinder body is inserted through a drilling hole, a reinforcing bar is installed in the drilling hole, a first hollow is provided, and an insertion hole through which a vertical bar constituting the reinforcing bar is inserted is provided. A first step of installing the first cylinder body above the reinforcing bar rod through the vertical bar through the hole, a concrete recovery tool having a second hollow and comprising the second cylinder body, the second hollow A second step in which a concrete recovery tool is provided in the first hollow, which is provided with an openable and closable slit, and a storage space for storing the recovered concrete in communication with the slit is provided in the second cylinder body; In the second of the collection tool A third step of placing concrete in the excavation hole through at least a halfway level of the second hollow, and suspending a weight in the second hollow; The concrete extruded to the hollow side of 2 is accommodated in the accommodation space through the slit of the second cylinder body, and the first cylinder body, the concrete collecting tool and the weight are excavated in a closed position. It is comprised from the 4th step by which the cast-in-place concrete pile from which the concrete of the upper part of casting concrete was collect | recovered is constructed | assembled.

  The construction method of the present embodiment separates the longitudinal main body protection cylinder body and the concrete recovery cylinder body instead of the concrete recovery tool having the longitudinal bar insertion hole and the accommodation space. A vertical cylinder protecting cylinder main body (first cylinder main body) is installed in the first cylindrical main body, and then the concrete hollow space is communicated with the second hollow in the first hollow of the first cylindrical main body. The second cylinder main body provided with the slit is installed, and the method configuration other than this is substantially the same as the construction method described above.

  This construction method can also solve all the problems of longer construction period, unexpected internal stress in the vertical bars, noise and vibration, and completely remove the low quality upper concrete. High quality cast-in-place concrete piles can be constructed.

  The present invention also extends to the concrete recovery device used in the construction method of the cast-in-place concrete pile described above. This concrete recovery device is constructed by installing a reinforcing bar in the excavation hole and placing concrete. A concrete recovery device that recovers the upper concrete of the cast concrete when constructing cast-in-place concrete piles, and is a hollow cylinder body that constitutes a reinforcing bar to be built in a drilling hole A concrete collecting tool comprising a cylinder body which has an insertion hole through which a line is inserted, and which has an openable and closable slit, and a storage space for storing the recovered concrete in communication with the slit. And concrete is placed in the excavation hole through the hollow of the concrete recovery tool, and the cast concrete is at least halfway through the hollow. A weight that is suspended in the hollow in a state of being reached, and the concrete extruded to the side of the hollow by the weight is accommodated in the accommodating space through the slit of the cylinder body, and the slit is closed By recovering the concrete recovery tool and the weight from the excavation hole in the above posture, the upper concrete of the cast concrete is recovered.

  By applying a concrete recovery device consisting of a concrete recovery tool and a weight to cast a cast-in-place concrete pile, an unintentional external force is applied to the vertical bars that make up the steel bar without causing noise or vibration. Therefore, it is possible to construct a high-quality cast-in-place concrete pile from which low-quality concrete above the concrete is effectively removed in a relatively short pile construction period.

  Further, another embodiment of the concrete recovery apparatus according to the present invention is such that a rebar is installed in the excavation hole, the concrete is placed on the upper part of the cast concrete when the cast concrete is piled by placing the concrete. A first cylindrical body having a first hollow, and having an insertion hole through which a vertical bar constituting a reinforcing bar built in a drilling hole is inserted; 1 is a concrete recovery tool having a second hollow body and comprising a second cylinder main body, and a slit that can be opened and closed in the second hollow. A concrete collecting tool in which an accommodation space for containing the concrete collected through communication is provided in the second cylinder body, and the concrete is placed in the excavation hole through the second hollow of the concrete collecting tool, And a weight suspended in the second hollow in a state where the cast concrete has reached the middle level of the second hollow, and is pushed to the side of the second hollow by the weight. The concrete is accommodated in the accommodation space through the slit of the second cylinder body, and the first cylinder body, the concrete collecting tool, and the weight are collected from the excavation hole in a posture in which the slit is closed. The upper concrete will be collected.

  The concrete recovery device of the present embodiment is a recovery device applied in the second embodiment of the method for constructing cast-in-place concrete piles described above, and is a cylinder body for protecting vertical bars that constitute a reinforcing bar rod ( It is a concrete recovery device in a form in which a first main body) and a main body (second main body) for collecting concrete are separated, and can achieve the same effects as the concrete recovery device described above. .

  As can be understood from the above description, according to the method for concrete cast-in-place pile and the concrete recovery device of the present invention, the concrete out of the concrete placed in the excavation hole while protecting the vertical bars constituting the reinforcing bar. Since the upper concrete is collected without waiting for its hardening, it is designed by extending the construction period, noise and vibration problems when crushing the hardened concrete, etc., and applying external force to the vertical bars during construction. The problem of internal stress that was not considered above is solved, and low-quality concrete is effectively recovered, and high-quality cast-in-place concrete piles can be constructed.

(A) is a figure explaining the 1st step of one Embodiment of the construction method of the cast-in-place concrete pile of this invention, (b) is the figure which showed the reinforcing bar rod with the perspective view. It is a perspective view of one embodiment of a concrete recovery device. It is the III-III arrow line view of FIG. FIG. 2 is a diagram for explaining a first step following FIG. It is a figure explaining a 2nd step. FIG. 6 is a diagram for explaining a second step following FIG. 5. It is a figure explaining a 3rd step. It is a figure explaining the state by which the slit was obstruct | occluded in the 3rd step. FIG. 8 is a diagram for explaining a third step following FIG. 7. It is a perspective view of other embodiment of a concrete collection | recovery apparatus.

  DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment of a cast-in-place concrete pile construction method according to the present invention and a concrete recovery device applied by the construction method will be described with reference to the drawings.

(First embodiment of construction method of concrete cast-in-place pile and concrete recovery device)
Fig. 1a and Fig. 4 to Fig. 9 are flow charts of an embodiment of a method for constructing cast-in-place concrete piles in that order, and Fig. 2 is an embodiment of a concrete recovery device applied by this construction method. It is a perspective view explaining the form of.

  First, as shown in FIG. 1a, the excavation hole G1 is created by applying any one of an earth drill method, an all-casing method, a reverse method, and the like to the ground G in the construction yard. Here, the excavation hole creation method is appropriately selected according to the construction conditions and ground properties at the site, the pile diameter and length of the cast-in-place concrete pile to be constructed, and the like.

  When the excavation hole G1 is formed, the bentonite stabilizing liquid (not shown) is filled in the excavation hole G1 to ensure the stability of the hole wall.

  Next, as shown in the perspective view of FIG. 1b, a reinforcing bar rod S formed by assembling a plurality of vertical bars S1 in a cylindrical shape with ring-shaped strips S2 arranged at a predetermined pitch in the vertical direction is formed in the excavation hole G1. Build in.

  Next, the concrete collecting tool 10 constituting the concrete collecting device 30 shown in FIG. 2 is fixed above the reinforcing bar S built in the excavation hole G1.

  Here, an embodiment of the concrete recovery apparatus will be outlined with reference to FIGS.

  The concrete recovery device 30 shown in the figure is composed of a concrete recovery tool 10 and a weight 20 that is loosely fitted in a hollow at the center of the concrete recovery tool 10.

  The concrete collecting tool 10 includes a tube body 1 made of steel or plastic. In the tube body 1, insertion holes 1b through which the vertical bars S1 constituting the reinforcing bar rod S are inserted are spaced apart in the circumferential direction. The hollow wall 1a facing the hollow is provided with slits 1c extending in the longitudinal direction at intervals in the circumferential direction. In addition to the illustrated example, the slit has a plurality of holes (not shown) arranged in the vertical direction at intervals to form a row of holes, and the holes are spaced in the circumferential direction of the hollow wall. The form provided, the form etc. which are provided with the slit extended in the circumferential direction not shown in figure at intervals in the vertical direction may be sufficient. Note that the thickness (length in the height direction) of the concrete recovery tool 10 and the weight 20 is adjusted to be approximately the same.

  The radix and pitch of the insertion holes 1b are set according to the number and pitch of the vertical bars S1 of the reinforcing bar rod S shown in FIG. 1, and all the vertical bars S1 can be inserted.

  Moreover, although it becomes easy to understand by referring to FIG. 3, an accommodation space 1 d for accommodating fresh concrete extruded by the weight 20 is provided inside the cylinder body 1, and the accommodation space 1 d is hollow. Each of the slits 1c facing the fluid is in fluid communication.

  As shown in FIG. 4, the concrete recovery tool 10 constituting the concrete recovery device 30 shown in FIG. 3 is suspended from the ground by the wire W1 into the excavation hole G1, and the reinforcing bar S is inserted into the insertion hole 1b while the vertical reinforcement S1 is inserted. The concrete recovery tool 10 is positioned and fixed to the upper part of. Note that the concrete recovery tool 10 is not fixed for securing the concrete recovery tool 10 to the hole wall of the excavation hole G1 in addition to a method of directly fixing the concrete recovery tool 10 by connecting it to the longitudinal bars S1. A method of placing a retaining anchor, or holding the concrete collecting tool 10 through the wire W1 with an appropriate fixing jig from the ground while the concrete collecting tool 10 is suspended from above the excavation hole G1. There are ways to do it.

  As shown in the figure, since the vertical bar S1 protruding above the reinforcing bar S is inserted and protected by the insertion hole 1b of the concrete collecting tool 10, an external force during construction acts on the vertical bar S1. There is no possibility that an internal stress that is not assumed in design by an external force is generated in the longitudinal stripe S1.

  As described above, FIGS. 1 and 4 are the first steps of the first embodiment of the construction method of the present invention.

  After the concrete collecting tool 10 is fixed at a predetermined position in the excavation hole G1, next, as shown in FIG. 5, the tremy pipe T is positioned inside the reinforcing bar S through the hollow of the concrete collecting tool 10, and excavated. Concrete C is placed in the hole G1 (X1 direction).

  This concrete placement is performed until the top end of the fresh concrete C placed as shown in FIG. 6 reaches the hollow midway level of the concrete collection tool 10 (height L from the lower end of the concrete collection tool 10).

  As mentioned above, FIG.5, 6 becomes the 2nd step of 1st Embodiment of the construction method of this invention.

  When the concrete is placed until the top of the fresh concrete C reaches the middle level of the hollow of the concrete collecting tool 10, the concrete collecting device 30 is constructed from the ground as shown in FIG. 7 before the fresh concrete C is hardened. The weight 20 to be suspended is suspended by the wire W2, the weight 20 is submerged in the fresh concrete in the hollow, and the suspension is performed until the lower end of the weight 20 comes to the lower end of the concrete recovery tool 10, Here, the weight 20 is held in a suspended posture.

  When the weight 20 sinks into the concrete, the upper concrete of the fresh concrete C existing in the hollow is pushed into the accommodation space 1d through the slit 1c of the concrete recovery tool 10 (X2 direction). And accommodated in the accommodating space 1d.

  Here, the concrete in the upper part of the placed concrete C is a low-quality (deteriorated) concrete containing a stabilizing liquid, latency, mud and mud, etc., so this low quality. The concrete is completely recovered in the accommodation space 1d.

  In addition, the weight of the weight 20 is adjusted to the weight which can sink at least in fresh concrete. The shape and size of the weight 20 are set to the shape and size that fit loosely in the hollow of the concrete recovery tool 10. Furthermore, the space volume of the accommodation space 1d provided in the concrete recovery tool 10 is obtained in advance by a rule of thumb or design of the volume of low-quality concrete to be removed, and the volume of space above this concrete volume. It is set to become.

  When the low-quality concrete is collected in the storage space 1d, as shown in the schematic diagram of FIG. 8, a closed lid 1e is attached to each slit 1c so that the low-quality concrete collected in the concrete collecting tool 10 does not fall out. Then, the concrete collecting tool 10 and the weight 20 are lifted and collected.

  Here, the method of attaching the lid 1e to the slit 1c is a method in which the lid 1e is automatically slidable on the entire surface of the slit 1c in advance, and the lid 1e is slid by a radio signal from the ground after collecting concrete. There are a method in which the lid 1e is suspended from the ground and slid while being engaged with the entire surface of the slit 1c, and a method in which an operator enters the excavation hole G1 and attaches the lid 1e. In addition, after the weight 20 is suspended in the hollow, both the concrete recovery tool 10 and the weight 20 are simultaneously recovered in a posture in which the weight 20 closes the slit 1c. When engaged with the concrete recovery tool 10 (ie, when the weight 20 is not loosely fitted in the hollow with a gap, but is frictionally engaged and fitted in the hollow), The form in which the weight 20 serves as a slit closing means and directly closes the slit 1c may be employed.

  When the concrete recovery device 30 is recovered from the excavation hole G1 and the cast concrete is hardened, the cast-in-place concrete pile P made of the high-quality concrete C from which the low-quality upper concrete is removed as shown in FIG. Construction is performed (third step).

  In the cast-in-place concrete pile construction method described above, the upper concrete of the concrete cast in the excavation hole G1 is collected without waiting for its hardening. Noise and vibration problems during crushing cannot occur.

(Second embodiment of construction method and concrete recovery device of cast-in-place concrete pile)
FIG. 10 shows a second embodiment of the concrete recovery apparatus. The concrete collecting device 30A shown in the figure is a concrete collecting device in a form in which a vertical bar protecting cylinder main body constituting the reinforcing bar S and a cylindrical main body (second cylinder main body) for collecting concrete are separated.

  Specifically, a first cylinder body 1A having a first hollow wall 1Aa and including an insertion hole 1Ab through which a longitudinal bar S1 constituting the reinforcing bar S1 built in the excavation hole G1 is inserted; A concrete collecting tool 10A, which is installed in the first hollow wall 1Aa, has the second hollow wall 1Ba, and is composed of the second cylinder main body 1B, and opens and closes to the second hollow wall 1Ba. A concrete recovery tool 10A in which a free slit 1Bc faces and an accommodation space 1Bd communicating with the slit 1Bc and containing the recovered concrete is provided in the second cylinder body 1B, and a second hollow of the concrete recovery tool 10B A weight 20A suspended in the second hollow wall 1Ba in a state where the concrete is placed in the excavation hole G1 through the wall 1Ba and the cast concrete has reached the middle level of the second hollow wall 1Ba. Or It is intended to be constructed.

  The second embodiment of the construction method of the cast-in-place concrete pile is different from the first embodiment of the construction method only in the steps resulting from the difference in the configuration of the concrete recovery device 30 and the concrete recovery device 30A. Since the other construction steps are the same as those in the first embodiment, they will be outlined with the illustration omitted (the same reference numerals as those in FIG. 1 and the like are applied as they are).

  In this construction method, as the first step, the excavation hole G1 is formed, the reinforcing bar S is built here, and the first bar is located above the reinforcing bar S through the vertical bar S1 in the insertion hole 1Ab of the first cylinder body 1A. The cylinder body 1A is installed.

  Next, as a second step, the concrete recovery tool 10A is installed in the first hollow wall 1Aa of the first cylinder body 1A (X3 direction in FIG. 10).

  Next, as a third step, the tremely pipe T is inserted into the excavation hole G1 via the second hollow wall 1Ba of the concrete recovery tool 10A, and concrete is placed to reach an intermediate level of the second hollow wall 1Ba. Let the cast concrete reach.

  Next, as a fourth step, the weight 20A is suspended in the second hollow wall 1Ba (in the X4 direction in FIG. 10), and the concrete extruded to the side of the second hollow wall 1Ba by the weight 20A is used. By collecting the first cylinder body 1A, the concrete collecting tool 10A, and the weight 20A from the excavation hole G1 in the posture of being accommodated in the accommodation space 1Bd through the slit 1Bc of the second cylinder body 1B and closing the slit 1Bc. The deteriorated concrete in the upper part of the cast concrete is collected, and a high-quality cast-in-place concrete pile P is constructed.

  As described above, in any of the construction methods of Embodiments 1 and 2, the upper concrete of the concrete placed in the excavation hole is hardened while protecting the vertical bars constituting the reinforcing bar rods. Because it is collected without waiting for a long period of construction, noise and vibration problems when crushing hardened concrete, and external forces during construction are applied to the vertical bars, which is not considered in the design The problem that internal stress is generated is solved, and low-quality concrete is effectively recovered, so that a high-quality cast-in-place concrete pile can be constructed.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and there are design changes and the like without departing from the gist of the present invention. They are also included in the present invention.

DESCRIPTION OF SYMBOLS 1 ... Cylinder main body, 1A ... 1st cylinder main body, 1B ... 2nd cylinder main body, 1Aa ... 1st hollow wall, 1a ... Hollow wall, 1Ba ... 2nd hollow wall, 1b, 1Ab ... Insertion hole, 1c , 1Bc ... slit, 1d, 1Bd ... accommodation space, 1e ... closed lid, 10, 10A ... concrete recovery tool, 20, 20A ... weight, 30, 30A ... concrete recovery device, G ... raw ground, G1 ... excavation hole, S: Steel bar, S1: Longitudinal bar, S2: Band, T: Tremy tube, W1, W2: Wire, C: Concrete (fresh concrete, hardened concrete), P: Cast-in-place concrete pile

Claims (4)

It is a construction method of cast-in-place concrete piles in which reinforced steel rods are built in the excavation holes, concrete is casted and cast-in-place concrete piles are constructed,
A concrete collecting tool comprising a hollow cylinder body, in which a drill hole is formed, a reinforcing bar is installed in the drill hole, and the cylinder body has an insertion hole through which a vertical bar constituting the reinforcing bar is inserted In addition, a slit that can be opened and closed freely opens in the hollow, and a storage space for storing the concrete collected in communication with the slit passes through the vertical bar to the insertion hole of the concrete recovery tool provided in the cylinder main body and above the reinforcing bar rod. The first step of installing the concrete recovery tool,
A second step of placing concrete in the excavation hole through the hollow of the concrete recovery tool, and reaching the cast concrete to at least an intermediate level of the hollow;
A weight is suspended in the hollow, and the concrete extruded to the side of the hollow by the weight is accommodated in the accommodation space through the slit of the cylinder body, and the concrete collecting tool and the weight are placed with the slit closed. A method for constructing a cast-in-place concrete pile comprising a third step in which a cast-in-place concrete pile in which the upper concrete of the cast concrete is recovered by being collected from the excavation hole. It is a construction method of cast-in-place concrete piles in which reinforced steel rods are built in the excavation holes, concrete is casted and cast-in-place concrete piles are constructed,
A drilling hole is formed, a reinforcing bar is installed in the drilling hole, a first hollow is provided, and a vertical hole is provided in the insertion hole of the first cylinder body provided with an insertion hole through which the vertical bar constituting the reinforcing bar is inserted. A first step of installing a first tube body above the rebar rod through the bar;
A concrete recovery tool having a second hollow and made of a second cylinder body, wherein a slit that can be opened and closed faces the second hollow, and a storage space for storing the recovered concrete communicated with the slit. A second step of installing a concrete recovery tool provided in the second cylinder body in the first hollow;
A third step of placing concrete in the excavation hole through the second hollow of the concrete collecting tool and reaching the cast concrete to at least a midway level of the second hollow;
A weight was suspended in the second hollow, and the concrete extruded to the side of the second hollow by the weight was accommodated in the accommodation space via the slit of the second cylinder body, and the slit was closed. It consists of a fourth step in which a cast-in-place concrete pile in which the upper concrete of the cast concrete is collected is constructed by collecting the first tube body, the concrete collecting tool and the weight from the excavation hole in the posture. Construction method for cast-in-place concrete piles. A concrete recovery device that collects the upper concrete of the cast concrete when building a cast-in-place concrete pile by placing a reinforcing bar in the excavation hole, placing the concrete,
A cylinder body having a hollow, provided with an insertion hole through which a vertical bar constituting a reinforcing bar to be built in a drilling hole is inserted, and facing the slit that can be opened and closed freely. A concrete recovery tool comprising a cylinder body provided with a storage space for storing the recovered concrete;
The concrete is placed in the excavation hole through the hollow of the concrete recovery tool, and at least in the state where the cast concrete has reached the middle level of the hollow, the weight is suspended from the hollow, and
The concrete extruded to the hollow side by the weight is accommodated in the accommodation space through the slit of the cylinder body, and the concrete collecting tool and the weight are collected from the excavation hole in a posture in which the slit is closed. A concrete collection device that collects the upper concrete of the installed concrete. A concrete recovery device that collects the upper concrete of the cast concrete when building a cast-in-place concrete pile by placing a reinforcing bar in the excavation hole, placing the concrete,
A first cylinder body having a first hollow and provided with an insertion hole through which a vertical bar constituting a reinforcing bar to be built in the excavation hole is inserted;
A concrete recovery tool configured to be installed in the first hollow, having a second hollow, and comprising a second cylinder body, wherein a slit that can be opened and closed faces the second hollow. A concrete collecting tool in which an accommodation space for accommodating the concrete collected in communication with the slit is provided in the second cylinder body;
Concrete is cast in the excavation hole through the second hollow of the concrete recovery tool, and the cast concrete is suspended in the second hollow in a state where the cast concrete has reached at least halfway through the second hollow. And a weight
The concrete extruded to the side of the second hollow by the weight is accommodated in the accommodating space through the slit of the second cylinder body, and the first cylinder body and the concrete collecting tool are in a posture in which the slit is closed. A concrete recovery device that recovers the upper concrete of the cast concrete by recovering the weight from the excavation hole.

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