JP2012154162A - Steel pipe pile and pile foundation construction method using the steel pipe pile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a steel pipe pile capable of reducing labor hours for construction and supporting a reinforcing bar cage to surely fix its position, with larger bearing force in the horizontal direction, and a pile foundation construction method using the steel pipe pile.SOLUTION: A steel pipe pile includes a vertically extending hollow pipe body 3 of which an upper part and a lower part are separated by a partition plate 33. The lower part has a tubular wall 32 provided with a plurality of communication holes 35 which allow for communication between the inside and outside of the hollow pipe body 3. The hollow pipe body 3 has an upper end which is sealed with a cap 31. A pile foundation construction method comprises the steps of inserting the pile into concrete placed in a pile hole, removing the cap after curing of the concrete, and placing the concrete after insertion of a reinforcing bar cage, so that the connection to the upper part is easily performed.

Description

  The present invention relates to a steel pipe pile and a pile foundation method using the steel pipe pile, and in particular, a steel pipe pile that has a high bonding force with the ground in the lateral direction and does not require a pile head treatment, and a pile that uses the steel pipe pile. The basic construction method.

  As a pile foundation construction method for constructing a foundation of a structure, for example, there is a method described in Non-Patent Document 1. Conventionally, for example, there is an embedded pile method performed in the procedure of (a) to (e) in FIG.

  In the procedure (a), first, the pit hole 21 is excavated in the ground by an excavator. Then, after pouring the ready-mixed concrete 100 into the pit hole 21 excavated in the procedure (b), the steel pipe pile 11 thinner than the inner diameter of the pit hole 21 is pushed into the pit hole 21 in the procedure (c). By pressing the steel pipe pile 11, the ready-mixed concrete 100 in the pit hole 21 is poured into the steel pipe pile from the lower end opening of the steel pipe pile 11 together with the pushing of the steel pipe pile 11, but a part of the ready-mixed concrete 100 is outside the steel pipe pile 11. Along the gap between the surface and the inner wall of the pit hole 21, it rises while mixing with impurities such as soil around the pit hole 21 in the ground, overflows from the upper end side of the steel pipe pile 11, and the upper end of the steel pipe pile 11 It flows into the pipe from the opening and becomes the poor blended concrete 101.

  Then, after the ready-mixed concrete 100 is solidified after a curing period of about 14 days, in the step (d), the pile head treatment is performed, that is, the soil around the upper end portion of the steel pipe pile 11, the poor blended concrete 101 inside and outside the steel pipe pile, etc. Then, the reinforcing bar 22 is installed in the steel pipe pile 11, and the position of the reinforcing bar 22 is temporarily fixed by the supporter 23 placed so as to cross the upper end surface of the steel pipe pile 11.

  Finally, when the ready-mixed concrete 102 is poured into the steel pipe pile 11 in which the reinforcing bar 22 is installed and the ready-mixed concrete 102 is solidified, the pile foundation of the structure is completed.

蕭 Wenda, “Civil Engineering, Chapter 6, Basic Process”, [online], October 12, 2007, Chaoyang University of Technology, [Search September 29, 2011], Internet <URL: http: // www .cyut.edu.tw / ~ wdshiau / teach / land / CH6.pdf>

  In the above-mentioned embedded pile construction method, since the upper end 111 of the steel pipe pile 11 used is opened, the poor-mixed concrete formed by mixing the ready-mixed concrete 100 and the soil around the hole 21 in the ground by the pushing of the steel pipe pile 11. Since 101 flows into the pipe of the steel pipe pile 11 from the upper end opening, it is necessary to perform a pile head process for removing the poor blended concrete 101 that has flowed into the pipe in the step (d).

  Further, in such an embedded pile method, the reinforcing bar 22 is suspended from the supporter 23 for temporarily fixing the reinforcing bar bar, so that almost all of the weight is supported by the supporter 23 and the supporter 23 has a considerable shear. In addition to being stressed, even in the final ready-mixed concrete pouring process, the position is not surely limited, and there is a high possibility that the position deviates from the ideal position.

  Furthermore, as shown in FIG. 8, the steel pipe pile 11 used for such an embedded pile construction method is a steel pipe pile 11 that extends straight, has no irregularities on the outer surface, and is horizontal from the ground. The supporting force (that is, the fixing force from the ground) is weak.

  In view of the above-mentioned problems, the present invention reduces the labor of construction, supports the reinforcing bar rod to ensure its position fixing, and obtains a stronger support force from the horizontal direction, and the steel pipe pile The purpose is to provide a pile foundation method using

  In order to achieve the above object, the present invention provides a hollow tubular body vertically extending vertically, wherein a plurality of communication holes are opened so as to communicate inside and outside the tube of the hollow tubular body, The upper end of the hollow tubular body provides a steel pipe pile characterized by being sealed with a cap.

  Preferably, the steel pipe pile further includes a partition plate that partitions the inside of the hollow tubular body into an upper space and a lower space, and all the communication holes are formed below the partition plate.

  In the steel pipe pile, it is preferable that two installation holes are opened on the upper side of the partition plate so as to face each other.

  In the steel pipe pile, the partition plate is a horizontally formed plate-like body, and the distance from the partition plate to the upper end of the hollow tubular body is the distance from the partition plate to the lower end of the hollow tubular body. It is preferable to set it to be shorter.

  In the steel pipe pile, the distance from the partition plate to the upper end of the hollow tubular body is preferably set to approximately 2000 mm.

  Moreover, this invention also provides the pile foundation construction method using the said steel pipe pile.

That is, an excavation step for excavating a borehole extending straight to the depth corresponding to the entire length of the steel pipe pile of the present invention from the opening to the ground above the opening on the ground;
A first concrete placing step for placing ready-mixed concrete in the excavated hole;
A steel pipe pile insertion step of inserting the steel pipe pile into the borehole so that the upper end part of the steel pipe pile is exposed before the cast concrete is solidified;
A cap removing step for removing the cap of the steel pipe pile after the cast concrete is solidified;
A reinforcing bar rod installation step for installing a reinforcing rod rod in the space inside the upper end part of the steel pipe pile from which the cap has been removed;
There is also provided a pile foundation method for sequentially executing a second concrete placing step in which concrete is placed and solidified in the space where the reinforcing bar is installed.

  In the pile foundation construction method, the length of the upper end part at which the steel pipe pile is exposed matches the length of the upper space in the steel pipe pile. After being installed in the upper space so as to be received by the partition plate, the fixing means is inserted from the outside of the hollow tubular body into the inside of the hollow tubular body via one installation hole in the two installation holes. The hollow tubular body and the reinforcing bar rod are installed so as to pass through the gap between the reinforcing rods and project through the other one of the two mounting holes and to the outside of the hollow tubular body. It is preferable that the position of the reinforcing bar is temporarily fixed by penetrating through the two.

  Furthermore, it is preferable to use an expanded cement as the cement in the concrete.

  With the above configuration, when the steel pipe pile of the present invention is pushed into the borehole into which the concrete has been poured in the pile foundation method of the present invention, the green concrete between the outer surface of the steel pipe pile and the inner surface of the borehole is ground. The concrete is mixed with the soil on the inner surface of the borehole in the soil (hereinafter referred to as soil-concrete mixture), and the concrete pushed inward from the lower end opening of the steel pipe pile is connected to the outside of the steel pipe pile through the communication hole. When the whole concrete is solidified, the concrete inside the steel pipe pile and the soil-concrete mixture outside are integrated through each communication hole. Therefore, the horizontal supporting force from the ground around the pothole is stronger than the conventional method.

  Moreover, since the upper end of the hollow tubular body is sealed with a cap, it is mixed with the soil around the pothole along the gap between the outer surface of the pipe pile and the inner wall of the pothole as the steel pipe pile is pushed in. However, since part of the rising concrete does not flow into the steel pipe pile from the upper end opening of the steel pipe pile and become poorly mixed concrete, the pile foundation method of the present invention can save the trouble of removing the poorly mixed concrete. .

  Further, by forming the two installation holes, the fixing means for temporarily fixing the reinforcing bar can be crossed the steel pipe pile through the two installation holes and the reinforcing bar can be held, and the second concrete can be held. When the concrete fills the pipe of the steel pipe pile in the placing step, the injected concrete enters the two installation holes and solidifies, so that the supporting force for the reinforcing bar can be increased.

  Further, since the partition plate is formed, the fixing means can be inserted after the reinforcing bar rod is installed in the upper space so that it can be received by the partition plate from below, so that the reinforcing bar can be inserted. Since the weight of the ridge does not apply to the fixing means due to the shear stress, it is not moved to the pouring of the ready-mixed concrete in the second concrete placing step and can be held at a proper position.

It is sectional drawing of 1st preferable embodiment of the steel pipe pile of this invention. It is a partially expanded sectional view of 1st preferable embodiment of the steel pipe pile of this invention. It is a flowchart of the pile foundation construction method using the steel pipe pile of this invention. It is explanatory drawing corresponding to each procedure of the pile foundation construction method using the steel pipe pile of this invention. It is explanatory drawing corresponding to each procedure of the pile foundation construction method using the steel pipe pile of this invention. It is explanatory drawing corresponding to each procedure of the pile foundation construction method using the steel pipe pile of this invention. It is explanatory drawing corresponding to each procedure of the pile foundation construction method using the steel pipe pile of this invention. It is explanatory drawing corresponding to each procedure of the pile foundation construction method using the steel pipe pile of this invention. It is explanatory drawing corresponding to each procedure of the pile foundation construction method using the steel pipe pile of this invention. It is an expanded sectional view in which the installation state of a reinforcing bar rod and its fixing means is shown. It is a partially expanded sectional view of 2nd preferable embodiment of the steel pipe pile of this invention. It is explanatory drawing by which an example of the conventional pile foundation construction method is shown. It is sectional drawing of the steel pipe pile used for the pile foundation construction example of FIG.

  Below, the pile foundation construction method using the steel pipe pile of this invention and this steel pipe pile is demonstrated in detail, referring each drawing.

  FIG. 1 is a sectional view of a first preferred embodiment of the steel pipe pile of the present invention, and FIG. 2 is a partially enlarged sectional view of the steel pipe pile.

  As shown in the drawing, the first preferred embodiment of the steel pipe pile of the present invention has a hollow tubular body 3 having a tubular wall 32 extending vertically up and down, and a plurality of communication holes 35 penetrating the tubular wall 32. Is opened so that the inside and outside of the tube of the hollow tubular body 3 communicate with each other, and the upper end of the hollow tubular body 3 is configured to be sealed with a cap 31.

  The hollow tubular body 3 further includes a partition plate 33 that partitions the in-pipe space 36 into an upper space 361 and a lower space 363, and all the communication holes 35 are formed below the partition plate 33. ing.

  Furthermore, two installation holes 34 are opened above the partition plate 33 so as to face each other.

  In the first embodiment, the partition plate 33 is a horizontally formed plate-like body, and the distance from the partition plate 33 to the upper end of the hollow tubular body 3 is from the partition plate 33 to the lower end of the hollow tubular body 3. It is arranged to be shorter than the distance. That is, the partition plate 33 is arranged in the tube of the hollow tubular body 3 so that the length of the upper space 361 in the vertical direction is shorter than the length of the lower space 363 in the vertical direction. Incidentally, in this 1st Embodiment, the distance from the partition plate 33 to the upper end of the hollow tubular body 3 is set to about 2000 mm.

  Then, the pile foundation construction method using the steel pipe pile of this invention is demonstrated in detail using FIGS. The effect of each structure of the steel pipe pile of the said invention is demonstrated with description of a pile foundation construction method.

  FIG. 3 is a flowchart of a pile foundation method using the steel pipe pile of the present invention, and FIGS. 4A to 4F show explanatory views corresponding to each procedure, and FIG. 5 shows a reinforcing bar 53 and its fixing means. It is an expanded sectional view in which the installation state of 54 (refer later) is shown.

  As shown in the flowchart of FIG. 3, the pile foundation method using the steel pipe pile of the present invention includes an excavation step 41, a first concrete placing step 42, a steel pipe pile insertion step 43, and a cap removal step 44. The rebar can be divided into a reinforcing bar setting step 45 and a second concrete placing step 46.

  FIG. 4A corresponds to the excavation step 41, and the excavation step 41 excavates a pothole 51 that extends straight from the ground to the ground. The length of the pit hole 51 is matched with the length of the lower space 363 below the partition plate 33 corresponding to the total length of the steel pipe pile of the present invention, and excavated so that the inner diameter is slightly larger than the outer diameter of the steel pipe pile. Is done.

  FIG. 4B corresponds to the first concrete placing step 42, and as shown in the figure, in this first concrete placing step 42, ready concrete 52 using expanded cement is placed in the excavated pothole 51. To do. The amount of the ready-mixed concrete 52 to be placed in the pothole 51 is smaller than the volume of the space in the pothole 51, and the cost of the ready-mixed concrete 52 can be suppressed by controlling so as not to overflow from the opening of the pothole 51 on the ground. it can. The ready-mixed concrete 52 used in this step can be, for example, one in which water and cement are mixed at a ratio of 1: 1, or further added with sand or gravel.

  FIG. 4C corresponds to the steel pipe pile insertion step 43, and in this steel pipe pile insertion step 43, the steel pipe pile is placed in the pit 51 before the ready-mixed concrete 52 placed in the first concrete placing step 42 is solidified. It is a process of inserting into or pushing into.

  In this step, the ready-mixed concrete 52 placed in the pit hole 51 mainly enters the lower space 363 from the lower opening of the communication hole 35 together with the insertion of the steel pipe pile, and the air in the lower space 363 is allowed to enter the communication hole 35. After being released to the outside via a portion, a part is pushed out from the communication hole 35 and merges with the ready-mixed concrete 52 outside the steel pipe pile. Accordingly, the ready-mixed concrete 52 inside and outside the pipe of the hollow tubular body 3 is connected via the communication hole 35 and is solidified and integrated. Also, the ready-mixed concrete 52 outside the steel pipe pile is slightly mixed with the soil on the inner peripheral surface of the pit hole 51 in the ground in this process to form a soil-concrete mixture. Therefore, the steel pipe pile after the ready-mixed concrete 52 solidifies. Is firmly fixed to the ground by strong bonding of the concrete inside and outside the hollow tubular body 3 respectively.

  Moreover, since the steel pipe pile of this invention is equipped with the cap 31 which seals the upper end of the hollow tubular body 3, the soil around the concrete 52 and the surrounding hole 51 mixes by insertion / push in of a steel pipe pile. It becomes possible to prevent the poor blended concrete from entering from above the hollow tubular body 3, and there is no need to perform pile head processing.

  Furthermore, as described above, the length of the pit hole 51 corresponds to the length of the lower space 363 below the partition plate 33 corresponding to the entire length of the steel pipe pile of the present invention, so the position of the partition plate 33 is , Substantially coincides with the ground, and all portions corresponding to the upper space 361 are exposed from the ground. That is, the length of a part of the upper end where the steel pipe pile of the present invention is exposed coincides with the length of the upper space 361.

  FIG. 4D corresponds to the cap removal step 44. This cap removal step 44 is performed after the cast concrete 52 is solidified, and is a step of removing the cap 31 of the steel pipe pile.

  FIG. 4E corresponds to the reinforcing bar rod installation step 45. In this reinforcing rod rod installation step 45, the reinforcing rod rod 53 and its fixing means 54 are installed.

  FIG. 5 is an enlarged view of the vicinity of the upper space 361 of the steel pipe pile in FIG. 4E. As shown in the drawing, the steel pipe pile upper space 361 from which the cap 31 is removed is placed on the upper surface of the partition plate 33. After the reinforcing bar 53 is installed, the lateral reinforcing bar as the fixing means 54 is inserted from the outside of the hollow tubular body 3 into the inside of the hollow tubular body 3 through one installation hole 34a in the two installation holes 34, The hollow tubular body 3 and the reinforcing bar rod 53 are installed so as to pass through the inside of the reinforcing rod 53 and project to the outside of the hollow tubular body 3 through the other one of the two installation holes 34b. , The steel rod 53 is temporarily fixed so that the position of the reinforcing bar 53 is not moved by the injection of the ready-mixed concrete 55 in the second concrete placing step 46 described below.

  Incidentally, the reinforcing bar rod 53 installed in this reinforcing bar rod installation step 45 has a plurality of reinforcing bars for connecting to the structure to be built on the ground so as to protrude upward from the upper end opening of the hollow tubular body 3. .

  FIG. 4F corresponds to the second concrete placing step 46. In this second concrete placing step 46, the ready-mixed concrete 55 is placed so as to fill the upper space 361 in which the reinforcing bar 53 has been installed. This is a process of solidifying.

  Thus, since the steel pipe pile of the present invention has a plurality of communication holes 35, the ready-mixed concrete 52 inside and outside the pipe of the hollow tubular body 3 is connected via the communication holes 35. As a result, it solidifies and integrates, and it can strengthen the binding force and frictional force with the soil in the lateral direction.

  Moreover, since the cap 31 which seals the upper end of the hollow tubular body 3 can prevent the penetration | invasion of poor mixing concrete by using the steel pipe pile of this invention, a pile head process is performed. There is no need.

  Furthermore, the reinforcing bar 53 used in the pile foundation method of the present invention is temporarily fixed by the fixing means 54 that passes through the two installation holes 34 and is also received by the partition plate 33 from below, so that the reinforcing bar 53 or the fixing is fixed. The positional deviation of the means 54 can be prevented.

  FIG. 6 is a partially enlarged cross-sectional view of a second preferred embodiment of the steel pipe pile of the present invention. As shown in the drawing, the steel pipe pile of the present invention can further include a plug 37 for sealing each of the two installation holes 34. By providing the plug 37, it is possible to prevent the poor blended concrete from entering the upper space 361 via the two installation holes 34.

  With the above configuration, the steel pipe pile of the present invention and the pile foundation method using the steel pipe pile are combined with the concrete of the steel pipe pile inside and outside using the communication hole 35, and the bonding force with the soil of the ground in the lateral direction. In addition to increasing the frictional force, the cap 31 can be used to prevent the infiltration of poor blended concrete from above and eliminate the need to perform pile head treatment, reducing the construction cost of the pile foundation and improving performance. Steel pipe piles can be provided.

3 Hollow tubular body 31 Cap 32 Tubular wall 33 Partition plate 34 Installation hole 34a Installation hole 34b Installation hole 35 Communication hole 36 Internal space 361 Upper space 363 Lower space 37 Plug 41 Excavation step 42 First concrete placement step 43 Steel pipe pile insertion step 44 Cap removal step 45 Reinforcement rod installation step 46 Second concrete placement step 51 Reinforcement hole 52 Ready concrete 53 Reinforcement rod 54 Fixing means 55 Ready concrete

Claims (8)

A plurality of communication holes are opened in the hollow tubular body vertically extending vertically so as to communicate the inside and outside of the tube of the hollow tubular body,
A steel pipe pile, wherein an upper end of the hollow tubular body is sealed with a cap.   2. The apparatus according to claim 1, further comprising a partition plate that partitions the inside of the hollow tubular body into an upper space and a lower space, wherein all the communication holes are formed below the partition plate. Steel pipe pile.   The steel pipe pile according to claim 2, wherein two installation holes are opened on the upper side of the partition plate so as to face each other.   The partition plate is a horizontally formed plate-like body, and the distance from the partition plate to the upper end of the hollow tubular body is shorter than the distance from the partition plate to the lower end of the hollow tubular body. The steel pipe pile of Claim 2 or Claim 3 characterized by the above-mentioned.   The steel pipe pile according to claim 4, wherein a distance from the partition plate to an upper end of the hollow tubular body is approximately 2000 mm. Excavation step for excavating a borehole extending straight from the ground to the depth corresponding to the entire length of the steel pipe pile according to any one of claims 1 to 5,
A first concrete placing step for placing ready-mixed concrete in the excavated hole;
Before the cast concrete solidifies, a steel pipe pile insertion step for inserting the steel pipe pile into the hole so that a part of the upper end of the steel pipe pile is exposed,
After the cast concrete has solidified, a cap removing step of removing the cap of the steel pipe pile;
A reinforcing bar rod installation step for installing a reinforcing rod rod in the space inside the upper end part of the steel pipe pile from which the cap has been removed;
A pile foundation method that sequentially executes a second concrete placing step in which concrete is placed and solidified in the space where the reinforcing bar is installed.   The steel pipe pile according to any one of claims 3 to 5 is used as the steel pipe pile, and a length of an upper end portion at which the steel pipe pile is exposed is equal to a length of an upper space in the steel pipe pile. In the rebar rod installation step, the reinforcing rod rods are installed in the upper space so that they can be received by the partition plate from below, and then the fixing means is installed from the outside of the hollow tubular body. The hollow tubular body is inserted into the inside of the hollow tubular body through one installation hole in the hole, passes through the inside of the reinforcing bar rod, and passes through the other one installation hole in the two installation holes. The pile foundation construction method according to claim 6, wherein the pile foundation construction method is installed so as to protrude outwardly of the steel plate and penetrates both the hollow tubular body and the reinforcing bar to temporarily fix the position of the reinforcing bar.   The pile foundation method according to claim 6 or 7, wherein an expanded cement is used as the cement in the concrete.

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