JP2009275377A - Steel pipe pile foundation structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a steel pipe pile foundation structure which is inexpensive and provides a high horizontal resistance even if a steel pipe pile is used in the foundation structure. <P>SOLUTION: A bottomed cylindrical space having a bottom plate 5 is formed at a given position inside steel pipe piles 4A and 4B placed into the ground, and concrete 6A is placed in the bottomed cylindrical space. It is preferable that a reinforcing bar 7 be disposed in the concrete 6A placed in the steel pipe piles 4A and 4B. The exterior of the steel pipe piles 4A and 4B placed into the ground is covered with concrete placed from above the steel pipe piles 4A and 4B to reach a given depth. It is preferable that a reinforcing bar be disposed in this concrete. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a steel pipe pile foundation structure using a steel pipe pile.

  In general, buildings such as reinforced concrete constructed on soft ground are supported by vertical piles such as reinforced concrete piles and steel pipe piles that are driven down to the support ground located below the soft ground. . However, such piles need to withstand horizontal loads such as earthquakes while supporting vertical loads. For this reason, in Patent Document 1, a building constructed on soft ground is supported by a support pile pin-bonded to the foundation slab, and a steel pipe pile is placed so as to cover the upper outer periphery of this support pile. A foundation structure in which a buffer material is filled between a steel pipe pile and a support pile is disclosed. As a result, the support pile is pin-bonded to the foundation slab, so that the bending moment generated in the support pile due to a horizontal load such as an earthquake is reduced, and the support pile is not constrained by the soft ground and is pinned in the steel pipe pile. Since it can be rotationally deformed around the part, the horizontal load can be attenuated. Furthermore, the upper outer periphery of a support pile can be protected with a steel pipe pile.

  Patent Document 2 confirms that the tip of the soil cement column can surely reach the support layer, and does not necessarily allow the tip of the steel pipe pile to reach the support layer. It aims at proposing the construction method of the soil cement synthetic pile which raises horizontal resistance in the neighborhood, and the soil cement synthetic pile. For this reason, this Patent Document 2 confirms that the tip has reached the support layer due to a change in the digging resistance value, and after constructing the soil sentiment pillar, at least near the head, near the tip, and in the daytime. Disclosed is a construction method for constructing a soil cement composite pile by inserting a winged steel pipe pile having a wing portion into a soil cement pillar. As a result, the steel pipe pile with wings is inserted into the soil cement pillar, so that the integrity of the steel pipe pile and the soil cement pillar is strengthened, and the vertical support capacity and horizontal resistance near the ground surface are also improved. .

  In Patent Document 3, a plurality of substructures provided in the ground have a diameter larger than the outer diameter of the pile so as to surround a pile of a plurality of standing structures in the ground with a predetermined range and interval. Steel formwork members (steel plates) are arranged almost coaxially, these formwork members are connected via steel underground beams, and concrete is filled in the steel formwork members to build a footing. Is disclosed.

  Patent Document 4 discloses a well-attached steel pipe member comprising a steel pipe pile made of a short pipe attached with inclined wings, and a casing connected to the steel pipe pile by a connecting means so as to be capable of transmitting torque and being detachable in the axial direction. After the winged replacement member is screwed and buried in the ground, a reinforcing bar or concrete pile is built into the winged steel pipe member, and concrete or a solidifying agent is placed or injected, and the casing is pulled out to form Disclose the cast-in-place pile.

Patent Document 5 shows that even if the pile head does not have a blade or a large-diameter cylindrical member, the pile head has a large resistance to horizontal load, and even when applied to the ground where the support layer is inclined, A pile with a soil cement composite wing having a structure capable of exhibiting a large resistance to a horizontal load at the pile head is disclosed.
JP 2000-303483 A JP 2002-201638 A JP 2002-309589 A Japanese Patent Laid-Open No. 2003-184078 JP 2006-233617 A

  As is clear from the above references, the foundation pile is required to have a sufficient horizontal resistance force as well as a vertical load. Moreover, in the conventional construction method, since the steel pipe material is selected based on the standard strength within the standard, the steel pipe wall thickness tends to increase significantly in order to achieve the necessary horizontal resistance. In addition, with the recent rise in steel pipe piles, an inexpensive foundation structure using steel pipe piles is required.

  For this reason, the present invention is to provide a steel pipe pile foundation structure that is inexpensive and has high horizontal resistance even when a steel pipe pile is used.

  Therefore, this invention exists in having the bottom plate part in the predetermined position inside the steel pipe pile penetrated in the ground, forming a bottomed cylindrical space, and arranging concrete in this bottomed examination space.

  Moreover, it is desirable that a reinforcing bar is disposed in the concrete disposed in the steel pipe pile. Furthermore, it is desirable that the bottom plate portion defining the bottomed cylindrical space and the reinforcing bar are connected.

  The bottom plate portion may have a flat plate shape, but it is desirable that the bottom plate portion is formed in a substantially conical shape in consideration of insertability.

  Furthermore, this invention exists in arranging concrete by the predetermined | prescribed depth from the upper side to the outer side of the steel pipe pile penetrated in the ground. Moreover, it is desirable that a reinforcing bar is arranged in the concrete.

  In addition, this steel pipe pile structure penetrates the steel pipe pile into the ground by rotation or driving, and excavates the outside of the steel pipe pile with a predetermined diameter and a predetermined depth by an outer excavation auger along the penetrated steel pipe pile. Then, a void tube is inserted and installed there. At this stage, the steel pipe pile foundation structure forming process is completed by inserting and installing reinforcing bars in the void pipe and filling it with concrete.

  According to the steel pipe pile foundation structure of the present invention, since the upper part of the steel pipe pile that penetrates the ground is reinforced with concrete from the inside or outside, the horizontal resistance near the ground surface can be improved at low cost. It can be done. Moreover, this can prevent the thickness of the steel pipe pile from being increased simply because the horizontal resistance force is increased.

  Embodiments of the present invention will be described below with reference to the drawings.

  A steel pipe pile foundation structure 1 according to Embodiment 1 of the present invention shown in FIG. 1 (a) penetrates through a soft ground 2 ′ while being sequentially joined through a joint 3 by placing in the ground 2 or by rotational penetration. The steel pipe piles 4A and 4B are provided so as to reach a support layer (not shown), and a concrete portion 6A in which concrete is filled in the steel pipe pile 4A located at the uppermost stage of the steel pipe pile. A bottom plate portion 5 for defining a bottomed cylindrical space filled with concrete at a predetermined position is fixed in advance to the steel pipe pile 4A located at the uppermost stage by welding.

  As a result, the upper part of the steel pipe pile is filled with concrete, so it is possible to increase the horizontal resistance force at the upper part of the steel pipe pile foundation structure with a simple structure. Therefore, it is possible to prevent the thickness from increasing only for the reason.

  The steel pipe pile foundation structure 1 which concerns on Example 2 of this invention shown in FIG.1 (b) is cylindrical from the vertical bar 7A and the horizontal bar 7B in the concrete part 6A of the steel pipe pile foundation structure which concerns on the said Example 1. FIG. The rebar part 7 in which is formed is provided. By this, since the horizontal resistance force in the upper part of the steel pipe pile foundation structure 1 can be further improved, it is possible to prevent the thickness of the steel pipe pile from being increased only because the horizontal resistance force is increased. It is.

  Moreover, you may connect the front-end | tip of the vertical bar 7A of the said reinforcing bar part 7, and the baseplate part 5 by welding. In this case, the bottom plate portion 5 is preferably an iron plate. Further, when the bottom plate portion 5 is formed of plastic, it may be fixed with an adhesive.

  In the steel pipe pile foundation structure 1 according to the third embodiment of the present invention shown in FIG. 2, the bottom plate portion 5 </ b> A is formed in a substantially conical shape, and is further fixed to one end portion of the vertical bar 7 </ b> A of the reinforcing bar portion 7. At the same time, the other end 7C of the vertical bar 7A of the reinforcing bar 7 is bent. As a result, it becomes easy to insert the reinforcing bar 5 into the steel pipe pile 5A, and its position can be easily fixed by the end 7C, so that fixing of the bottom plate 5A by welding can be omitted. It is. As a result, like the first and second embodiments, it is possible to prevent the steel pipe pile from being thickened only for the reason of increasing the horizontal resistance force.

  The steel pipe pile foundation structure 1 which concerns on Example 4 of this invention shown to Fig.3 (a) is formed with the following method. First, (1) the steel pipe pile 4A is driven up to the support layer. (2) The hole 9 is formed by excavating the outside of the steel pipe pile 4A in a cylindrical shape along the steel pipe pile 4A to a predetermined depth by an outer excavation auger (not shown). (3) The void tube 8 is installed in the hole 9 excavated in a cylindrical shape. (4) Fill the void pipe with concrete to form the concrete portion 6B.

  Thereby, since the concrete part 6B is formed outside the upper part of the steel pipe pile 4A, the horizontal resistance force at the upper part of the steel pipe pile 4A can be increased. Thereby, it is possible to prevent the steel pipe pile from being thickened only for the reason of increasing the horizontal resistance force.

  The steel pipe pile foundation structure 1 which concerns on Example 5 of this invention shown in FIG.3 (b) is formed with the following method. First, (1) the steel pipe pile 4A is driven up to the support layer. (2) The hole 9 is formed by excavating the outside of the steel pipe pile 4A in a cylindrical shape along the steel pipe pile 4A to a predetermined depth by an outer excavation auger (not shown). (3) The void tube 8 is installed in the hole 9 excavated in a cylindrical shape. (4) Between the void pipe 8 and the steel pipe pile 4A, a reinforcing bar formed in a cylindrical shape by a vertical bar 7A 'and a horizontal bar 7B' is arranged to provide a cylindrical reinforcing bar part 7 '. (5) The void pipe is filled with concrete to form a concrete portion 6B having a reinforcing bar portion 7 '.

  Thereby, since the concrete part 6B which has the reinforcing bar part 7 'is formed outside the upper part of the steel pipe pile 4A, the horizontal resistance force at the upper part of the steel pipe pile 4A can be increased. Thereby, it is possible to prevent the steel pipe pile from being thickened only for the reason of increasing the horizontal resistance force.

(A) is a schematic block diagram of the steel pipe pile foundation structure which concerns on Example 1 of this invention, (b) is a schematic block diagram of the steel pipe pile foundation structure which concerns on Example 2 of this invention. It is a schematic block diagram of the steel pipe pile foundation structure which concerns on Example 3 of this invention. (A) is a schematic block diagram of the steel pipe pile foundation structure which concerns on Example 4 of this invention, (b) is a schematic block diagram of the steel pipe pile foundation structure which concerns on Example 5 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Steel pipe pile foundation 2 Ground 2 'Soft ground 3 Joint 4A, 4B Steel pipe pile 5 Bottom plate part 6A, 6B Concrete part 7, 7' Reinforcing bar part 7A, 7A 'Vertical bar 7B, 7B' Horizontal bar 8 Void pipe 9 Hole

Claims (7)

  A steel pipe pile foundation structure characterized in that a bottomed cylindrical space is formed at a predetermined position inside the steel pipe pile penetrated into the ground, and a concrete is arranged in this bottomed examination space.   The steel pipe pile foundation structure according to claim 1, wherein a reinforcing bar is arranged in the concrete arranged in the steel pipe pile.   The steel pipe pile foundation structure according to claim 2, wherein the bottom plate portion defining the bottomed cylindrical space and the reinforcing bar are connected.   The steel pipe pile foundation structure according to any one of claims 1 to 3, wherein the bottom plate portion is formed in a flat plate shape.   The steel pipe pile foundation structure according to claim 3, wherein the bottom plate portion is formed in a substantially conical shape.   A steel pipe pile foundation structure characterized in that concrete is arranged at a predetermined depth from above on the outside of a steel pipe pile penetrated into the ground. The steel pipe pile foundation structure according to claim 6, wherein reinforcing bars are arranged in the concrete.

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