JP2007217947A - Pile head processing construction method and simple charge holder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pile head processing construction method capable of easily and highly accurately processing a pile head in low vibration and low noise in a short period. <P>SOLUTION: In this pile head processing construction method, a ring-shaped horizontal partition plate 34 is prearranged inside the pile head to a cast-in-place concrete pile, and a high energy substance 35 is installed in a simple charge holder 21 having a dynamic action concentrating rectangular cavity 1 of an exploded shock wave and/or expanded gas pressure inside the pile head. Crack progress in the substantially vertical direction to a pile from a wall surface of a charge hole 5, is controlled by using the concentrative effect of the exploded shock wave and/or the expanded gas pressure generated in the charge hole, and the dynamic effect of the exploded shock wave and/or the expanded gas pressure generated in the charge hole is reflected or guided by the horizontal partition plate. Concrete of a part for processing the pile head is separated by controlling the crack progress in the substantially horizontal direction along the horizontal partition plate by using its effect. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a pile head processing method and a simple charge holder in which a pile head processing of a cast-in-place concrete pile is performed by a dynamic crushing method.

  In the pile head treatment of cast-in-place concrete piles, most of the work is crushing work by human power, so prolonged vibration and crushing noise have made local residents uncomfortable and have a great impact on the work process. Therefore, shortening vibration and noise is a major issue. In addition, although crushing work by human power is done by taking dust measures such as covering with dustproof sheets, fine concrete dust diffuses under the influence of wind, so reducing dust is a major issue It is. On the other hand, although the number of sites that adopt static crushing methods using chemical reactions is increasing, the crushing effect is small, and most of the remaining work is done by human power as in the past, so the living environment in the neighborhood has been improved much. There is no current situation.

  Against this background, a conventional technique for controlling the direction of cracks in a short time is a method of creating a stress concentration effect by notching the explosive hole wall using a water jet (see below). Patent Document 1), a method of creating a stress concentration effect by slitting a tubular sleeve (the following Non-Patent Documents 2 and 3), directional hydraulic blasting using a semicircular reflector (the following Non-Patent Document 4) )and so on.

  The following Patent Document 1 discloses a steel bar for a cast-in-place concrete pile that crushes the surplus portion for removing a defective portion (excess portion) of the pile head. Moreover, the following patent document 2 attaches a receiving object to a predetermined position of a reinforcing bar head, arranges a gap forming block on the receiving object, and drives a wedge into an opening from which the block has been removed after placing the concrete, thereby adding surplus concrete. Disclosed is a pile head processing method that can be pulled out.

Furthermore, Patent Document 3 below controls crack direction control using a charge holder having a wedge-shaped cavity that produces not only the effect of concentration of applied force as a static action but also the effect of concentration of explosion shock waves as a dynamic action. Disclose the blasting method that enables it.
Shigeru Iisei, Jun Kawakami, Takafumi Igarashi, Kenji Nakao, Journal of Industrial Explosives Association, Vol.48, No.6, 1987, pp.369-377 WLFourney, JWDally, DCHolloway, Int.J.Rock Mech.Min.Sci. And Gemech.Abstr.Vol.15, 1978, pp.121-129 Katsuhisa Katsuyama, Hiroshi Kiyokawa, Koichi Sasa, Mining and Security, Vol. 29, No. 4, 1983, pp. 16-23 Hiroshi Hashimoto, Jun Takagi, Journal of Japan Society of Civil Engineers, September 1979, pp.57-66 Japanese Patent Publication No.62-16286 JP-A-57-21623 Japanese Patent Publication No. 08-12040

  In the conventional construction method described above, problems remain in the adverse effects on the living environment due to the prolonged construction period, the complexity of the blasting apparatus, and the like. The present invention provides a pile head processing method and a simple charge holder capable of performing pile head processing easily and with high accuracy in a short period of time with low vibration and low noise in view of the above-mentioned problems of the prior art. For the purpose.

  The present inventors use high energy substances such as concrete crushers belonging to explosives or explosives, and not only the stress concentration effect as a static action, but also the effect of concentration of an explosion shock wave and expansion gas pressure as a dynamic action. Using a simple charge holder combined with an L-shaped member having a rectangular cavity to be generated, it is possible to control the crack in the vertical direction with respect to the pile, and further, these dynamic effects are reflected or reflected by a ring-shaped horizontal partition plate The crushing control method that induces and controls horizontal cracks reduces the amount of dust and enables pile head processing with low vibration and low noise in a short period of time. It has been conceived.

  That is, the first pile head processing method according to the present invention is a concrete crushing belonging to explosives or explosives in a simple charge holder having a rectangular cavity in which dynamic action of explosion shock wave and / or expansion gas pressure is concentrated inside the pile head. By attaching a high-energy substance such as a container and controlling the crack propagation from the wall surface of the charge hole using the concentration effect of the explosion shock wave and / or the expansion gas pressure generated in the charge hole, It is characterized by crushing the concrete of the part which performs head processing.

  According to the first pile head processing method, the wall surface of the charge hole is utilized by utilizing the concentration effect of the explosion shock wave and / or the expansion gas pressure generated in the charge hole using the simple charge holder having a rectangular cavity. By controlling the crack propagation from the pile, concrete can be crushed without damaging the pile body. For this reason, the amount of dust can be reduced, and the pile head processing can be performed easily and accurately with low vibration and low noise in a short period of time.

  In the first pile head processing method, the crack propagation in the substantially vertical direction can be controlled with respect to the pile by the arrangement of the simple charge holder. Moreover, it is preferable that the said simple charge holder is comprised combining an L-shaped member so that the said rectangular cavity may be formed.

  In the second pile head processing method according to the present invention, a cast-in-place concrete pile is preferably provided with a ring-shaped horizontal partition plate in the pile head in advance so as not to interfere with the tremy pipe, and the concrete crushing belonging to explosives or explosives. Reflecting the dynamic effect of the explosion shock wave and / or the expansion gas pressure of a high energy material such as a vessel on the horizontal partition plate or guiding the expansion gas horizontally on the horizontal partition plate to the horizontal partition plate It is characterized by controlling the crack propagation in the substantially horizontal direction along and horizontally separating the concrete of the part to be piled up.

  According to the second pile head processing method, the dynamic effect of the explosion shock wave and / or the expansion gas pressure is reflected or induced by the horizontal partition plate provided in the pile head in advance, and the effect is used to create the horizontal partition plate. By controlling the crack propagation along the substantially horizontal direction, the concrete can be crushed without damaging the pile body. For this reason, the amount of dust can be reduced, and the pile head processing can be performed easily and accurately with low vibration and low noise in a short period of time.

  In the third pile head processing method according to the present invention, a ring-shaped horizontal partition plate is preferably installed in the pile head in advance so that it does not interfere with the tremy pipe for the cast-in-place concrete pile. Alternatively, a high-impact material such as a concrete crusher belonging to explosives or explosives is attached to a simple charge holder having a rectangular cavity where the dynamic action of expansion gas pressure is concentrated, and an explosion shock wave generated in the charge hole and / or Alternatively, the crack growth in the substantially vertical direction is controlled with respect to the pile from the wall surface of the charge hole by utilizing the concentration effect of the expansion gas pressure, and the explosion shock wave and / or the expansion gas generated in the charge hole By reflecting the dynamic effect of pressure at the horizontal partition plate or by inducing expansion gas in the horizontal direction at the horizontal partition plate to control the crack propagation in the substantially horizontal direction along the horizontal partition plate, Pile head Characterized in that to separate the concrete part for performing management.

  According to the third pile head treatment method, the pile from the wall surface of the charge hole is made using the concentration effect of the explosion shock wave and / or the expansion gas pressure generated in the charge hole using the simple charge holder. In contrast, the crack propagation in the substantially vertical direction is controlled, and at the same time, the dynamic effect of the explosion shock wave and / or expansion gas pressure is reflected or induced by the horizontal partition plate provided in the pile head in advance, and the effect is used. By controlling the crack propagation in the substantially horizontal direction along the horizontal partition plate, the portion of the concrete subjected to the pile head treatment can be separated without damaging the pile body. For this reason, the amount of dust can be reduced, and the pile head processing can be performed easily and accurately with low vibration and low noise in a short period of time.

  In the third pile head processing method, the simple charge holder is preferably configured by combining L-shaped members so that the rectangular cavity is formed.

  Further, in the first to third pile head processing methods, a reflection member that reflects the impact due to the explosion shock wave or the expansion gas pressure is used to prevent a damage to the pile outer periphery due to the explosion shock wave or the expansion gas pressure. It is preferable to arrange in the part. Thereby, even if it performs the pile head process by high energy substances, such as a concrete crusher which belongs to explosives or explosives, damage to a pile outer peripheral part can be prevented and a regular pile diameter can be ensured.

  The simple charge holder according to the present invention is used in the first to third pile head processing methods described above. According to this simple charge holder, the pile main body is controlled by controlling the crack propagation from the wall surface of the charge hole using the concentration effect of the explosion shock wave and / or the expansion gas pressure generated in the charge hole. Since it is not damaged, the amount of dust can be reduced, and it is possible to perform pile head processing easily and accurately with low vibration and noise in a short period of time.

  According to the pile head processing method and simple charge holder of the present invention, the pile body can be processed without damaging the pile body, so the amount of dust can be reduced, and it is easy and high with low vibration and low noise in a short period of time. Pile head processing can be performed with high accuracy.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  <Simple charge holder>

  FIG. 1 is a diagram for explaining a simple charge holder for pile head processing according to this embodiment, and is a plan view of an L-shaped liner which is an L-shaped member constituting the simple charge holder (a). , A front view (b), a plan view (c) of an equilateral angle steel that is a modification of the L-shaped member, a front view (d), and a plan view (e) of an improved L-shaped liner that is a modification of the L-shaped member It is a front view (f).

  FIG. 2 is a plan view of a simple charge holder combining the L-shaped liners of FIGS. 1 (a) and 1 (b) (a), and a simple charge combining the equilateral mountain shaped steels of FIGS. 1 (c) and (d). It is a top view (b) of a holder, and the top view (c) of the simple charge holder which combined the improved L-shaped liner of FIG.1 (e), (f).

  As shown in FIGS. 1 (a) and 1 (b), the L-shaped liner 11 is composed of plane portions 11a and 11b whose cross-sectional shapes are substantially equilateral, and the plane portions 11a and 11b are coupled at a substantially right angle to form an L shape. For example, it can be manufactured by bending a steel plate.

  As shown in FIG. 2 (a), the simple charge holder 21 according to the present embodiment combines the L-shaped liners 11 and 11 shown in FIGS. 1 (a) and 1 (b) at the combination parts 2 and 2 at each end. A rectangular cavity 1 configured and formed inside extends in the longitudinal direction of the L-shaped liner 11. The simple charge holder 21 is installed at a predetermined position of the pile head of the pile reinforcement, and a concrete crusher belonging to explosives or explosives is loaded into the rectangular cavity 1 after placing the concrete pile. .

  The modification of the above-mentioned L shape member and a simple charge holder is demonstrated. 1 (c) and 1 (d), the equilateral angle steel 12 is composed of plane portions 12a and 12b having substantially equal sides in cross-section, and the plane portions 12a and 12b are coupled at a substantially right angle. For example, it can be manufactured by rolling. As shown in FIG. 2 (b), the simple charge holder 22 is constructed by combining the equilateral angle steels 12 and 12 of FIGS. 1 (c) and 1 (d) with the combination parts 2 and 2 at each end. The formed rectangular cavity 1 extends in the longitudinal direction of the equilateral angle steel 12.

  Further, the improved L-shaped liner 13 which is an L-shaped member in FIGS. 1E and 1F is composed of flat portions 13a and 13b having substantially equal sides in cross section, and the flat portions 13a and 13b are about 120 degrees. Are combined to form a substantially L shape, and can be manufactured, for example, by bending a steel plate. As shown in FIG. 2 (c), the simple charge holder 23 is configured by combining the equilateral angle irons 13 and 13 shown in FIGS. 1 (e) and (f) with the combination parts 4 and 4 at each end. The formed rectangular cavity 3 extends in the longitudinal direction of the improved L-shaped liner 13. The rectangular cavity 3 has a rhombus shape with opposing angles of about 120 degrees and about 60 degrees, respectively.

  Next, the use of the simple charge holder will be described with reference to FIGS. FIG. 3 is a partial cross-sectional view in the pile vertical direction schematically showing an arrangement state of the simple charge holder according to the present embodiment inside the pile head.

  FIG. 4A is a plan view schematically showing how an explosion shock wave propagates in a rectangular cavity in the simple charge holder of FIG. 3, and the reflected shock wave reflected by the inner wall surface of the simple charge holder of FIG. FIG. 3B is a plan view schematically showing a state of proceeding toward the cavity combination part, and FIG. 3B is a partial plan view schematically showing a state in which the reflected shock wave becomes stronger when the cross section of the rectangular cavity is reduced and a concentration effect is generated. FIG. 4C is a partial plan view schematically showing the direction in which the reflected shock wave further concentrates and the cracks progress.

  As shown in FIG. 3, the simple charge holder 21 having the rectangular cavity 1 of FIG. 2 (a) combined with the L-shaped liners 11, 11 of FIGS. In addition to being preliminarily installed in the direction, a ring-shaped horizontal partition plate 34 is preliminarily installed in the lower lateral direction of FIG.

  The pile head processing part 31 of the concrete pile 30 is formed with a charge hole 5 in which the simple charge holder 21 is located. In this pile head process part 31, the top of the simple charge holder 21 is exposed after the concrete is hardened. In the rectangular cavity 1 of the simple charge holder 21, a high energy substance 35 such as a concrete crusher belonging to explosives or explosives is mounted at a position corresponding to a substantially central position of the pile head processing unit 31 in a decoupled state.

  Further, on the upper and lower portions of the high-energy substance 35 in the simple charge holder 21 installed at a substantially central position in the vertical direction of the pile head processing unit 31 in FIG. 3, there are polystyrene foam material 36 and sand (or flake powder). 33, and further, the cement-based fast-strength material 32 is disposed above and below the sand 33, so that the charge hole 5 is in a tamped and sealed state, and from the hole of the charge hole 5 at the time of explosion. This prevents the expansion gas pressure from blowing out. Further, the leg 36 is led out from the high energy material 35 to the outside.

  Next, when the high-energy substance 35 loaded in a decoupling state having an air gap around the rectangular cavity 1 in FIG. 3 is detonated or detonated, as shown in FIG. A shock wave or expansion wave a due to the shock or expansion gas pressure propagates outward in the rectangular cavity 1 of the simple charge holder 21 in a substantially circular shape as shown by a broken line in the figure.

  Then, as shown in FIG. 4B, the shock wave or the expansion wave is reflected on the inner wall surface of the simple charge holder 21 other than the rectangular cavity 1, and a substantially circular reflected shock wave like the broken line in the figure in the rectangular cavity 1. b travels toward the combination part 2 of the rectangular cavity 1 while interfering with it.

  At this time, since the cross section of the rectangular cavity 1 is reduced toward the combination part 2 as shown in the figure, the stronger the reflected shock wave or the reflected expansion wave b goes to the combination part 2 as shown in FIG. A concentration effect is produced. Then, as shown in FIG. 4 (d), a crack is generated in the pile head processing unit 31 due to a dynamic effect that the reflected shock wave or the reflected expansion wave b further approaches the combination unit 2 and the concentration effect further increases as shown in FIG. In (d), the crack progresses in the direction k, and the crack progresses in the longitudinal direction y as a whole.

  Then, the dynamic effect is reflected or guided by the ring-shaped horizontal partition plate 34 almost simultaneously with the crack propagation in the vertical direction y, so that the horizontal direction along the horizontal partition plate 34 of FIG. Cracks also progress at x.

  As described above, by using the simple charge holder 21 according to the present embodiment, the charge hole is utilized by utilizing the concentration effect / dynamic effect of the explosion shock wave and the expansion gas pressure generated in the charge hole 5. 5 controls the crack growth in the vertical direction y from the wall surface 5 and also controls the crack growth in the horizontal direction x along the horizontal partition plate 34, so that the pile body of the concrete pile 30 is not damaged and pile head treatment is performed. The concrete of the part 31 can be separated with high accuracy.

  In addition, the crack direction can be controlled by generating an explosion shock wave concentration effect as a dynamic action as shown in FIGS. 4 (a) to 4 (d). Therefore, the direction of crack propagation can be controlled by matching the position of the combination part 2 of the rectangular cavity 1 with the planned crushing surface direction.

  In addition, it is possible to control damage prevention near the crushing hole wall by the auxiliary effect of the decoupling of the charge and the simple charge holder 21, and to control the blowing of the expansion gas to other than the planned crushing surface. Reduction can also be realized. This also means that the conversion effect of the explosion energy is increased, and the amount used can be reduced.

  3 and 4, the simple charge holder 22 of FIG. 2B in which the equilateral angle steels 12 and 12 of FIGS. 1C and 1D are combined may be used, and the same effect as described above. Can be obtained.

  Further, the simple charge holder 23 of FIG. 2C combined with the improved L-shaped liners 13 and 13 of FIGS. 1E and 1F may be used. In this case, the combination portion of the simple charge holder 23 is used. The angle of 4 and 4 is about 60 degrees, which is smaller than 90 degrees of the combination parts 2 and 2 of the simple charge holders 21 and 22 of FIGS. 2 (a) and 2 (b). 4), the concentration effect / dynamic action of the reflected shock wave b shown in FIGS. 4C and 4D is further increased, so that the crack progress is improved, which is preferable. Therefore, by adjusting the angle of the improved L-shaped liner 13 (120 degrees in FIG. 1E), it is possible to control the above-described concentration effect / dynamic action.

  <Pile head processing method>

  Next, the pile head processing method according to the present embodiment will be described more specifically with reference to FIG.

  FIG. 5 is a plan view (a) schematically showing an embedded state of the simple charge holder and the ring-shaped horizontal partition plate before the pile head treatment in order to explain the pile head treatment method according to the present embodiment and the upper part in the vertical direction. It is sectional drawing (b).

  As shown in FIGS. 5A and 5B, a plurality of pile main bars 41 extending in the longitudinal direction of the concrete pile 30 to be placed are arranged on the circumference in a plane at substantially equal intervals, and the plurality of pile main bars 41 are arranged. By placing the ring-shaped shear reinforcement bars 42 so as to surround the piles, the pile reinforcement rods are assembled. A plurality of shear reinforcement bars 42 are arranged at substantially equal intervals in the longitudinal direction of the concrete pile 30 as shown in FIG.

  As shown in FIGS. 5A and 5B, a ring-shaped horizontal partition plate 34 is disposed in the horizontal direction above the ends of the plurality of pile main bars 41, and extends in the vertical direction above the horizontal partition plate 34. A plurality of simple charge holders 21 similar to those in FIG. 3 are arranged. As shown in FIG. 5A, the plurality of simple charge holders 21 are arranged on the horizontal partition plate 34 on a concentric circle at substantially equal intervals. In this case, each simple charge holder 21 is installed so that the planar direction of the combination parts 2 and 2 shown in FIGS. 4 (a) to 4 (d) is substantially in the radial direction as shown in FIG. 5 (a). The

  Moreover, although the length of the simple charge holder 21 is substantially equivalent to the pile head processing part 31 of the concrete pile 30, the pile head processing part 31 is shaped by the pile head shaping level i of FIG. Therefore, it is preferable that the horizontal partition plate 34 is arranged so that the horizontal crushing level h indicated by a broken line in FIG.

  As shown in FIG. 5A, the ring-shaped horizontal partition plate 34 is formed with a tremely tube insertion hole (concrete passage hole) 34a at the center, and a plurality of slime / air passage holes 34b. Are arranged at substantially equal intervals on the concentric circles, and the respective simple charge holders 21 are located between the respective through holes 34b.

  Further, an impact reflection ring 43 is installed on the outer periphery of the pile main reinforcement 41 of the pile reinforcement rod so as to surround the plurality of pile main reinforcements 41, and the shock wave or expansion gas pressure propagated along the horizontal partition plate 34. Is reflected to prevent damage to the outer periphery of the pile due to impact and to ensure a proper pile diameter.

  Next, steps S01 to S11 of the pile head processing method in the pile head processing section of FIGS. 5A and 5B will be described with reference to the flowchart of FIG.

  As shown in FIGS. 5A and 5B, the pile reinforcement rods are assembled by the plurality of pile main bars 41 and the plurality of shear reinforcement bars 42 (S01). And the horizontal partition plate 34 is installed in the upper part of the pile rebar corresponding to the pile head process part 31 by a ground structure (S02), and also the some simple charge holder 21 is installed (S03). In this manner, concrete is placed in a state where the horizontal partition plate 34 and the plurality of simple charge holders 21 are integrated with the pile reinforcement rods (S04).

  Next, after the concrete is hardened (S05), internal cleaning is performed from the hole of the simple charge holder 21 exposed from the top of the concrete (S06). The high energy substance 35 is loaded into the medicine holder 21 (S07) and set in the state shown in FIG.

  Next, when the high-energy substance 35 loaded in each simple charge holder 21 is detonated or detonated (S08), the shock wave accompanying the detonation or the expansion wave due to deflagration is compressed from around each simple charge holder 21. The crack propagates along the fracture surface in the vertical direction (longitudinal direction) due to the expansion gas pressure generated later or the tension wave reflected on the free surface (S09), and further, the explosion shock wave or the expansion The waves reach the ring-shaped horizontal partition plate 34. Since this ring-shaped horizontal partition plate 34 is a different member from concrete, the ring-shaped horizontal partition plate 34 and its ring-shaped horizontal partition plate 34 are separated by the dynamic effect of the explosion shock wave and the expansion wave. At this point where peeling occurs at the boundary of the upper concrete, cracks develop along the horizontal crushing surface in the horizontal crushing zone (S10). The expansion gas pressure that arrives later than the explosion shock wave advances along the separation interface, and new crack growth is promoted at the same level other than the installation of the ring-shaped horizontal partition plate 34. These series of phenomena act in a short time in the pile head processing unit 31 of the cast-in-place concrete pile 30.

  As described above, the pile head processing unit 31 crushes the concrete without damaging the pile body (S11).

  As described above, the explosion shock wave or the expansion wave propagates from each simple charge holder 21 to the outside, the crack progresses along the vertical crushing surface, and the upper part of the ring-shaped horizontal partition plate 34 and the concrete Cracks develop in the horizontal direction at the interface. This horizontal crack propagates at the horizontal crushing level h indicated by the broken line in FIG. 5B, and by making the horizontal crushing level h coincide with the pile head shaping level i, it is possible to control crack propagation in two directions in a single operation. Become.

  According to the pile head processing method of the present embodiment, by combining the rectangular cavities 1 with the rectangular cavities 1 inside the simple charge holder 21, intentional effects of concentration of explosion shock waves and expansion gas pressure are created. The shock wave and the expansion wave in the state become a high pressure state by the self-amplification action, and the direction of the stress distribution in the charge hole 5 is generated. Each simple charge holder 21 is mounted so that the combination portions 2 and 2 of the rectangular cavity 1 coincide with each other in the planned crushing surface direction, and the crack is combined by the dynamic action of the shock wave and the expansion wave as described above. 2 and 2, and the expansion gas pressure generated subsequently proceeds along the crack, and further crack growth is promoted. Further, if each simple charge holder 21 is integrated with the surroundings, the rectangular cavity 1 of the simple charge holder 21 exerts a stress concentration effect. Blowing out is suppressed, and the residual gas pressure effectively increases the crushing action.

  As described above, in the pile head processing of cast-in-place concrete piles, the vertical and horizontal crack growth is controlled almost simultaneously with the vertical preparation work, and the pile head processing can be performed in a short period of time with low vibration and low vibration. It can be applied to noise, and the pile main body can be crushed without damaging the pile body, so the amount of dust can be reduced and a pile head treatment method with good construction accuracy can be realized.

  As described above, the best mode for carrying out the present invention has been described. However, the present invention is not limited to these, and various modifications are possible within the scope of the technical idea of the present invention. For example, the pile head processing method of the present embodiment can also be applied to a pile head processing unit having a configuration as shown in FIGS. FIG. 7 is an embedded state of the simple charge holder and the ring-shaped horizontal partition plate before the pile head treatment in order to explain the pile head treatment method of the pile head treatment part which is a modification of FIGS. 5 (a) and (b). They are a top view (a) and a vertical direction upper cross-sectional view (b).

  In the example of FIGS. 7A and 7B, the upper end portions 41a of the plurality of pile main bars 41 constituting the pile reinforcement rod extend beyond the pile head shaping level i into the pile head processing section 31 of the concrete pile 30. Except for this, the configuration is the same as in FIGS. Even in the case of a concrete pile having a pile reinforcement rod in which the tip upper portion 41a of the pile main reinforcement 41 extends to the inside of the pile head treatment section 31 as shown in FIGS. 7 (a) and (b), the pile head treatment section as in FIG. 31 can be piled up and the same effect as described above can be obtained.

  5 and 6, a concrete crusher belonging to explosives or explosives as a high-energy substance can be mounted inside the simple charge holder 21.

It is a figure for demonstrating the simple charge holder for the pile head process by this Embodiment, Comprising: The top view (a) of the L-shaped liner which is an L-shaped member which comprises a simple charge holder, A front view ( b), a plan view (c), a front view (d), and a plan view (e), a front view (e) of an improved L-shaped liner, which is a modified example of the L-shaped member. f). A plan view of a simple charge holder combining the L-shaped liners of FIGS. 1 (a) and 1 (b) (a), a plan view of a simple charge holder combining the equilateral angle irons of FIGS. 1 (c) and 1 (d) It is a top view (c) of the simple charge holder which combined the improved L-shaped liner of (b) and FIG.1 (e), (f). It is a partial cross section figure of the pile vertical direction which shows roughly the arrangement state in the pile head inside of the simple charge holder by this embodiment. FIG. 3A is a plan view schematically showing a state in which an explosion shock wave propagates in a rectangular cavity in the simple charge holder of FIG. 3, and a combination part of the rectangular cavity where the reflected shock wave reflected by the inner wall surface of the simple charge holder in FIG. FIG. 3B is a plan view schematically showing the state of traveling toward the point B, and FIG. 3B is a partial plan view schematically showing how the reflected shock wave in FIG. And a partial plan view (d) schematically showing the direction in which the reflected shock wave further concentrates and the crack progresses. In order to explain the pile head processing method according to the present embodiment, a plan view (a) and a vertical upper cross-sectional view schematically showing the embedded state of the simple charge holder and the ring-shaped horizontal partition plate before the pile head processing ( b). It is a flowchart for demonstrating process S01 thru | or S11 of the pile head processing method in the pile head processing part of Fig.5 (a), (b). The plane which shows the embedding state of the simple charge holder before a pile head process, and a ring-shaped horizontal partition plate in order to demonstrate the pile head process method of the pile head process part which is a modification of Fig.5 (a), (b) It is a figure (a) and a longitudinal direction upper cross-sectional view (b).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,3 Rectangular cavity 2,4 Combination part 5 Charge hole 11 L-shaped liner (L-shaped member)
12 Equilateral angle steel (L-shaped member)
13 Improved L-shaped liner (L-shaped member)
21, 22, 23 Simple charge holder 30 Concrete pile 31 Pile head processing section 34 Horizontal partition plate 34a Tremy tube insertion hole, concrete passage hole 35 High energy material 41 Pile main reinforcement 42 Shear reinforcement 43 Impact reflection ring (reflective member) )
h Horizontal crushing level i Pile head shaping level x Horizontal direction y Vertical direction k Crack progress direction

Claims (8)

  Explosion shock wave and / or expansion gas generated in the charge hole by attaching a high energy substance to a simple charge holder having a rectangular cavity where the dynamic action of explosion shock wave and / or expansion gas pressure is concentrated inside the pile head A pile head treatment method characterized by crushing the concrete of the part to be pile head treated by controlling the crack propagation from the wall surface of the charge hole using the pressure concentration effect.   The pile head processing method according to claim 1, wherein crack propagation in a substantially vertical direction is controlled with respect to the pile by the arrangement of the simple charge holder.   The pile head processing method according to claim 1 or 2, wherein the simple charge holder is configured by combining L-shaped members so that the rectangular cavity is formed.   A ring-shaped horizontal partition plate is pre-installed inside the pile head for cast-in-place concrete piles, and the dynamic effect of the explosion shock wave and / or expansion gas pressure of high energy material is reflected by the horizontal partition plate or expanded gas Pile head treatment characterized in that the horizontal partition plate is guided in the horizontal direction to control crack propagation in the substantially horizontal direction along the horizontal partition plate, and the concrete of the portion to be subjected to the pile head treatment is horizontally separated. Construction method. Pre-install a ring-shaped horizontal partition plate inside the pile head for cast-in-place concrete piles,
Explosion shock wave and / or expansion gas generated in the charge hole by attaching a high energy substance to a simple charge holder having a rectangular cavity where the dynamic action of explosion shock wave and / or expansion gas pressure is concentrated inside the pile head While controlling the crack growth in the substantially vertical direction with respect to the pile from the wall surface of the charge hole using the pressure concentration effect,
Reflecting the dynamic effect of the explosion shock wave and / or the expansion gas pressure generated in the charge hole by the horizontal partition plate or guiding the expansion gas in the horizontal direction by the horizontal partition plate, the horizontal partition A pile head treatment method characterized by separating the concrete of the part to be piled up by controlling crack propagation in a substantially horizontal direction along the plate.   The pile head processing method according to claim 5, wherein the simple charge holder is configured by combining L-shaped members so that the rectangular cavity is formed.   The reflective member which reflects the impact by the said explosion shock wave or the said expansion gas pressure has arrange | positioned in the said pile outer peripheral part in order to prevent the damage of the pile outer peripheral part by the said explosion shock wave or the said expansion gas pressure. Pile head processing method described in 1. The simple charge holder used for the pile head processing method of any one of Claims 1 thru | or 7.

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