JPS5938429A - Treatment work of head of buried concrete pile - Google Patents

Abstract

PURPOSE:To construct the supporter of footing without lowering of the strength of the pile head by a method in which the head of a concrete pile is removed by chipping, a cylindrical reinforcement is provided on the periphery of the pile head, and a convexed-spherical face supporter is provided on the cylindrical reinforcement. CONSTITUTION:The head of a buried concrete pile 1 is removed by chipping, and a reinforcement 3 having a skirt 2 on its lower end is covered on the periphery of the pile head for a reinforcing treatment for the pile head with lowered strength by chipping. A concrete 5-filled footing supporter 6 having a convexspherical face S on its upside is placed on the upper flange 4 of the reinforcement 3 by providing an adhesive 7 on the downside of the supporter 6 and both the supporter 6 and the upper flange 4 are connected by welding. A fixing metal 17 having a nut 9 on its lower end is pierced through the hole 8 of the supporter 6, and a footing 10 is placed so as to embrace the metal 17. The supporter to support the footing with pin-connection can thus be constructed without lowering of the strength of the pile head.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention proposes a method for structurally barring the pile heads of ready-made concrete piles buried underground, which is effective in preventing destruction due to horizontal forces during earthquakes.

For joining the pile cap and footing of concrete piles,
- There are two types: one by re-coupling and the other by pin axis alignment.

In the case of a rigid connection, the largest bending moment is generated at the pile head, as shown in Figure 1 (a), due to the horizontal force caused by the +11 pair movement between the ground and the ground structure during an earthquake. However, in the case of pin connection, the same figure (b)
As shown in , no bending moment acts on the pile DJJgi+.

Therefore, in order to bring the bending moment of the pile head due to the horizontal force during an earthquake as close to zero as possible, it is desirable to set the pile Mn condition to the bottle-down condition, and to install a concrete pile with a convex spherical pile head in the ground. By burying it, a pin connection between the pile cap and the footing can be achieved.

However, it is extremely difficult to bury such pre-fabricated concrete piles with the head height constant, or the depth of burial varies depending on the ground conditions. This method requires multiple concrete piles with different sizes, which lacks versatility and has the disadvantage of increasing production costs.

Therefore, the present inventors buried a commonly used 2-I concrete pile to a predetermined depth and chipped off the concrete pile head so that the head of the buried concrete pile was at a predetermined height above the ground. An attempt was made to make the pile head spherical, but cracking occurred on the pile head during chipping, and this caused the horizontal force during an earthquake to create a bending moment on the load bearing part of the pile head. However, the pile head fH is susceptible to collapse due to horizontal force, and furthermore, it is subject to excessive vertical downward stress due to the weight of the above ground structure due to vertical return during an earthquake. Therefore, it was concluded that there was a great risk that the collapsed pile head would collapse, and that it could be fully expected to cause uneven settlement of the plow, although the degree of collapse may vary. .

The present invention was made in view of such concerns, and the method for treating the head of a buried concrete pile according to the present invention is to raise the head of a ready-made concrete pile buried underground to a predetermined height above the ground. So that it will be eight-trimmed, shi-dokoro-kon, and yatsuri-remo shi-dokoro-Jζ be applied to the outer periphery corresponding to the pile head after the chiseling process, or to the outer periphery of the pile head after the chiseling process, The present invention is characterized in that a reinforcing body according to the commercial method is provided, and a convex spherical support body for supporting the footing by pin connection is provided on the pile head after the chipping process described in tji+.

According to the above construction method, the effect of what the present inventors tried earlier is achieved, that is, by using ready-made concrete piles that are extremely simple and therefore inexpensive to manufacture, the head of the pile is raised to a predetermined height above the ground. In addition to being able to connect the footings with pins while the pile is in an upright position, it also prevents the pile cap from collapsing after chipping and treatment, thereby preventing the weight of the above-ground structure and the vertical downward movement of the pile due to the pitching motion of an earthquake. The authors proposed a construction method that would provide a pile cap structure that is strong enough to withstand the horizontal and vertical forces of an earthquake, even when the stress is applied.

Hereinafter, the pile cap treatment method according to the present invention will be explained with reference to the drawings from FIG. 2 onwards.

First, as shown in No. 21J, a ready-made concrete pile 1 used for construction work is buried in the ground to a predetermined depth so that its lower end reaches the hard plate A, as shown in Fig. 3. As shown in FIG.
And, remove PC &)-Kia...

Next, as shown in FIG. 4, a reinforcing body 3 with a skirt 2 provided on the lower end side is attached to the outward facing part of the pile head after chipping of the buried concrete pile 1, and its upper part 7 flange 4 is attached to a predetermined position. The pile caps, whose strength has been weakened by chipping, are reinforced by covering them with large pieces of dust located on the plowed ground. In other words, the strength of the pile head is reduced due to cracking of the pile head concrete due to chipping, etc., and the strength of the pile head is increased to increase the strength to withstand horizontal car loads. A footing support 6 with a curved top surface S filled with a pile cap structure and a slat 5 is filled with resin mortar or adhesive 7 on the F side and the pile cap to form the upper flange 4.上ECIl'i iff L, SO (7) Both 4
．． 6 is connected to iW (by tying the pile 1a, the pile head condition is changed to a pin-connected structure).

In addition, the support body 6 is formed with a hole 8 in the vertical direction extending one spherical center of the curved castle surface S in the center thereof, and furthermore, in the lower surface plate 6σ, a hole 8 is formed in the vertical direction. A footing fixing member 117i is attached to the footing fixing member 117i through the through hole 8, and a nut 9 is attached thereto.

In this way, a footing 10 was built on the top of the 47-f slope 1a.
To cast, prepare a threaded iron cutter, threaded iron a, etc. with a footing constant of Min1s, and screw it onto the +iiJ mark J49 with a large dust that protrudes above the convex spherical surface S.
Anchor fittings 11 such as clamps are attached as necessary.

On the other hand, as shown in FIG. 6, a metal fitting 12 having a concave curved spherical surface that is surface-fitted from above to the protruding curved surface S of the OiJ support 6 is attached to the anchor metal fitting 11 to which the metal fitting 12 is attached as necessary. In this surface-fitting method, the Mij recorder is attached to both 6 and 1 so that the metal fitting 12 can easily slide relative to the support 6.
A treatment to reduce the frictional force is performed by interposing an Amephalt cloth, a Teflon (trade name) coating, a Teflon-impregnated strong glass fiber cloth, etc. between the two mating surfaces. w, b in Figure 4 indicates a layer for reducing frictional force.

Next, concrete for the footing 10 is poured into the receiver with the lower flange 13 of the metal fitting 12 facing downward, thereby joining the footing 10 to the pile head of the concrete pile 1a.

According to the above configuration, the support body 6 and the metal fitting 12 of the support body 6 and the metal fitting 12 are slidable relative to each other by their spherical shafts, that is, the footing 10 is in a pin-coupled state with respect to the buried concrete pile 1a. Bending moments due to horizontal forces such as these are not applied to the pile cap.

In addition, even if the footing 10 moves relative to the pile cap due to the horizontal force, because of the spherical fitting, the load of ground pickles transmitted through the footing 1D is always distributed over the entire area of the pile cap. In addition, a reinforcing body 3 is provided on the outer periphery of the pile head after the peeling process to strengthen its resistance against horizontal forces, thereby preventing the pile head from collapsing due to horizontal force. This collapse prevention means that the ground surface, fii
The reinforcing support body 6 is connected in advance by bath welding.
It's not easy, but if you make it a separate structure, you can use hatsumode mortar and removal agent 7.
It is easy to reliably fill the reinforcing body 3, and it is also easy to set the height of the reinforcing body 3. Furthermore, prior to the chipping process of the concrete pile head, the reinforcing body 3 can be set at the location where it is in contact with the pile head after the chipping process, thereby preventing the occurrence of cracks due to chipping. Effective in prevention.

FIG. 7 shows a first alternative embodiment, in which the chipper 1! ! !
A reinforcing body 14 of the commercial method that fits into the inner peripheral part of the pile cap is attached to the lower plate 6a of the support 6, and the reinforcing body 3 of the pile cap
．． The feature is that it is reinforced both inside and outside by 14.

Figure 8 shows a second example of separate fibers, with buried concrete pile 1
PC steel + Aa... such as threaded joint ironwork and threaded reinforcing bar exposed when the pile head concrete was removed was cut to a predetermined length. The arrangement b pitch and tl of ... are in phase with the Sada tuna hole 15.
... is provided, and M is installed in the h' oil hole 5...
iJWKiPC Mausoleum+Aa...and force it through,
A nut 16 is screwed onto the PC wire 4fltl....

Note that the nif support 6 may have a hollow structure, or may be made of concrete itself.

[Brief explanation of drawings]

Figures 1 (a) and (b) are moment diagrams, 218I and later are related to the present invention, Figure 2 is an explanatory diagram of embedding a ready-made concrete pile, and Figure 8 shows the condition of the pile head concrete being ``pulled''. Explanatory drawings, Fig. 4 is a sectional view showing the installed state of the footing bolt, Fig. 5 is a concave drawing of the footing section where the bedhead is treated, Fig. 6 is an explanatory drawing of the footing support, Fig. 7 The figure is a cross-sectional view showing the first separate application vj, and FIG. 8 is a cross-sectional view showing the second separate example. 1...Ready-made concrete pile, 3 sleeve reinforcement, 6...
・Footing support, 10 river footing, S...
Surrounded by a curved castle. Figure 1 Figure 2 Figure 3 Figure 5 Figure 6 Leap

Claims (1)

[Claims] The concrete pile head of a ready-made concrete pile buried in the ground is processed by chipping so that the head has a predetermined ground clearance, and the concrete corresponds to the pile cap after being chipped prior to the chipping process. In addition to providing a bolt bolt on the outer part or on the outer periphery of the pile head after the sharpening process, a footing for supporting the footing by pin connection to the pile head after the sharpening process. A pile head processing method for buried concrete piles characterized by providing a convex spherical support.