JP4117295B2 - H-type PC pile and bottom plate connection structure - Google Patents

Description

  The present invention relates to a combined structure of an H-shaped PC pile and a bottom plate.

  When building an underpass to make a crossroad into a three-dimensional intersection, or when building a basement in the ground, etc., connect a square PC pile that is resistant to bending as a side wall, and install a self-supporting concrete retaining wall. There is technology to form.

  As a pile that forms a self-supporting concrete retaining wall, the present applicant provides a precast concrete pile (H-type PC pile) having an H-shaped cross section (see, for example, Patent Document 1).

  This H-shaped PC pile has a large bending strength, can resist earth pressure only with the member body, can be easily packed between piles, and can easily form a strong vertical earth retaining wall, Moreover, the wall body excellent in water-stopping property can be formed. Using this H-shaped PC pile, space is formed in the basement and land is effectively used, especially in urban areas.

In such an underground structure, it is easy to make the retaining wall surface itself and the bottom slab itself formed by the H-type PC pile into a water-stopping structure, but the connection part between the H-type PC pile and the bottom slab is at the time of an earthquake. Due to liquefaction and lateral flow, the earth pressure is always higher than that, so a sufficient structure is required for the cross-sectional force such as bending moment to satisfy the performance required for the structure. The required performance is, for example, waterstop. In particular, in the basement where the underground space is effectively used, flooding should be avoided.
Application for Japanese Patent Application No. 2003-187926

  In view of the fact that the present invention is optimal for forming a self-supporting retaining wall with an excellent H-shaped PC pile, in the basement formed with the H-shaped PC pile, the joint between the H-shaped PC pile and the bottom plate is always The object of the present invention is to provide a bonded structure having a predetermined strength and rich in water-stopping during a level 1 earthquake, and having a high toughness with high rotational performance during a level 2 earthquake.

  The present invention provides a coupling plate on the flange outer surface of the portion of the H-type PC pile that is in contact with the bottom slab concrete at the joint between the wall surface of the H-type PC pile driven into the ground and the concrete bottom slab concrete in contact with the H-type PC pile. The connecting plate passes through the web of the H-type PC pile and is connected to a plurality of penetrating PC steel materials fixed to the fixing plate inside the flange on the anti-bottom plate side of the H-type PC pile and the penetrating PC steel materials. This is a combined structure of an H-shaped PC pile and a bottom slab characterized by comprising a PC steel material that extends and settles in the bottom slab, and an attachment portion for attaching a reinforcing bar in the bottom slab.

  The coupling structure of the H-type PC pile and the bottom slab of the present invention is such that the wall formed by connecting the H-type PC pile and the concrete bottom slab concrete in contact with the H-type PC pile are connected to each other via a coupling plate. It is a prestressed reinforced concrete joint structure. Therefore, there is no crack in the joint portion, and even if it occurs, the crack or the like has a resilience that closes when unloaded.

  The coupling plate may be a rectangular steel plate having a width slightly narrower than the flange width of the H-type PC pile, and is provided on the outer surface of the flange of the H-type PC pile near the upper surface and the lower surface of the bottom slab concrete. Good.

  It is preferable that the coupling plate is provided with reinforcing ribs in the plane because the bending rigidity is improved.

  ADVANTAGE OF THE INVENTION According to this invention, it is the coupling | bonding structure of an H-shaped PC pile and a bottom slab, Comprising: It has the predetermined performance requested | required of a coupling | bond part, is rich in a recoverability, and can obtain the coupling | bonding structure with a high water stop.

  That is, this joint structure can suppress cracking of the joint part at the time of design load by arranging PC steel and introducing compressive force to the joint between the H-type PC pile and the bottom slab. To do. In addition, there is a resilience that returns to the original state when the load is unloaded. Since the tensile force generated in the reinforcing bars in the bottom slab concrete is transmitted to the fixing body on the back of the H-type PC pile through the PC steel material, many shear fracture surfaces can be secured against the tensile force, and the tensile force is also safe. is there.

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

  FIG. 1 is a partial plan view of an underground structure showing a coupling structure between an H-shaped PC pile 10 and a bottom slab 20 according to an embodiment of the present invention, and FIG. 2 is a view taken along the line AA in FIG. These are the BB arrow line view and CC arrow line view of FIG. 2, respectively.

  The H-type PC pile 10 is continuously arranged as shown by 10a, 10b,... In FIG. The bottom plate 20 side of the retaining wall is a space other than the bottom plate 20, and the anti-bottom plate side is underground. The bottom plate 20 has a large area and is coupled to the H-type PC piles 10, 10a, 10b,. FIG. 1 shows a part thereof.

  A coupling plate 30 is embedded in the surface of the flange 11 on the bottom plate side of the H-shaped PC pile 10. As shown in FIG. 2, the coupling plates 30 are respectively disposed at upper and lower positions close to the upper surface and the lower surface of the bottom plate 20, and are exposed in the joint joint between the H-type PC pile 10 and the bottom plate 20.

  The coupling plate 30 includes couplers 32 and 33 into which end portions of a plurality of PC steel materials 41 are screwed. The PC steel material 41 penetrates through the web 13 of the H-type PC pile 10 and extends into the flange 12 on the back side of the H-type PC pile 10 and is fixed to the fixing plate 40 disposed in the flange 12 by the fixing tool 42. Is done. The PC steel material 41 may be an unbonded PC steel bar.

  Further, a PC steel material 50 extending into the bottom plate 20 is attached to the coupling plate 30. The PC steel material 50 extends into the bottom plate 20, and its extended end is fixed to a fixing joint 23 in the bottom plate 20 by a fixing tool 51. The reinforcing bars 21 are supported by the fixing plate 40 provided in the anti-bottom plate side flange 12 of the H-type PC pile 10 via the plural (two in the embodiment) PC steel materials 41.

  The coupling plate 30 is provided with a number of couplers 35 into which the ends of the reinforcing bars 21 in the bottom plate 20 are screwed. With respect to the bending moment generated in the coupling plate 30 due to the tensile force of the reinforcing bars 21, ribs 34 are provided on the back surface of the coupling plate 30.

  The PC steel material 50 is provided in order to reduce the crack width generated in the joint joint, and may be disposed in the sheath 52 or may be an unbonded PC steel rod. The H-type PC pile 10 and the bottom plate 20 are connected to the PRC structure by the rebar 21 and the PC steel material 50.

  Although the shape of the coupling plate 30 is not particularly limited, in the embodiment, the coupling plate 30 has a substantially rectangular shape slightly narrower than the width of the flange 11 of the H-type PC pile 10.

  Examples of the coupling plate 30 are shown in FIGS. 5 (a) to 5 (c). 5 (b) is a front view (a view seen from the outer surface of the flange 11 of the H-shaped PC pile 10, that is, a view taken along the line BB in FIG. 2), FIG. 5 (a) is a rear view thereof, and FIG. c) is a side view. The coupling plate 30 of the embodiment is composed of a rectangular steel plate 31, and couplers 32 and 33 for fixing a PC steel material 41 penetrating through the web of the H-type PC pile 10 are attached to the back surface thereof. In addition, a rib 34 projects from the back surface of the steel plate 31 and a coupler 35 is provided for screwing the end of the reinforcing bar in the bottom plate 20. A hole having a diameter equal to or greater than the diameter of the reinforcing bar passes through the coupling plate 30 at the position where the coupler 35 is installed, and the end of the reinforcing bar 21 of the bottom plate 20 is coupled to the coupler 35. The coupler 32 can freely move through a hole formed in the coupling plate 30.

The bonding structure of the present invention can be formed by the following procedure.
(A) At the time of manufacturing the H-shaped PC pile 10, the coupling plate 30 and the penetrating PC steel material 41 are disposed at positions to be coupled to the bottom plate 20 to pre-cast the H-shaped PC pile 10. The penetrating PC steel 41 is preferably an unbonded PC steel rod and fixed to the fixing plate 40.
(B) The H-type PC pile 10 is driven into the ground to form a retaining wall, and the coupling plate 30 is exposed by excavating the retaining wall.
(C) The end of the reinforcing bar 21 disposed in the bottom plate is coupled to the coupler 35 of the coupling plate 30 and the sheath PC steel material 50 is attached, and then the concrete of the bottom plate 20 is placed. When the sheath is not installed, the PC steel material 50 is preferably unbonded.
(D) After the placed concrete is hardened, the PC steel material 50 in the bottom plate 20 is tensioned to complete the construction of the bonded structure of the present invention.

It is a top view of an Example. It is an AA arrow line view of FIG. It is a BB arrow line view of FIG. It is CC arrow line view of FIG. It is a rear view of a rectangular coupling plate. It is a front view of a rectangular coupling plate. It is a side view of a rectangular coupling board.

Explanation of symbols

10, 10a, 10b H-type PC pile 11, 12 Flange 13 Web 20 Bottom plate 21 Reinforcing bar 22 Fixing part 23 Joint 30 Bonding plate 31 Steel plate 32, 33, 35 Coupler 34 Rib 40 Fixing plate 41 PC steel material 42 Fixing tool 50 PC steel material 51 Fixing tool 52 Sheath

Claims (1)

At the joint between the wall of the H-type PC pile driven into the ground and the concrete bottom slab concrete in contact with the H-type PC pile,
A connecting plate is vertically attached to the outer surface of the flange of the H-shaped PC pile in contact with the bottom slab concrete, and the connecting plate passes through the web of the H-shaped PC pile and is fixed inside the flange on the opposite side of the H-shaped PC pile. An H-type PC pile and a bottom slab characterized by comprising a penetration PC steel material of a book and a PC steel material which is connected to the penetration PC steel material and extends and settles in the bottom slab, and an attachment portion for attaching a reinforcing bar in the bottom slab And the combined structure.

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