US2008307A - Twigged pile - Google Patents

Description

Patentediuly 16, 1935 UNITED `STAT Shigeyuki Kanamori, Araijuku, morikiLfTokyo, v ,Japan-", Application September 275,1934, SerialNo. 7 45,392y

, In Japan September 30, 1933 2 Claims.

5 after loading and so constructed as to be easily driven. The object thereof is to obtain such a foundation pile as has its supporting power increased by the twigs and can resist oblique external force, if necessary. Y

Referring to the annexed drawing which shows an example of this invention,

Figure l is the elevation of my pile in a driven state;

Figure 2, the planof the same and Y Figure 3, an example of my pile used as the foundation of a culvert.

As shown in Figure 1, the pile according to my invention is formed by attaching the pointed rodshaped twigs B and B to a trunk A at an acute angle so constructed as to be easily driven. y

It is made of concrete reinforced by steel C to prevent it from being detached or damaged during driving or after loading.

The number and position of the twigs B and B and the number of the positions of attaching them should be determined according to the ground into which the pile is to be driven. The twigs are attached to the trunk in one or more steps in such a manner that when the point D of the trunk has reached the hard'bed E of the i ground, each of them B and B may be driven in the hard layer F on the way. When there are more than two steps of the twigs to be attached, it is preferable that the lower ones are smaller than the upper ones.

For the sake of economy, in many cases the twigs are provided at the part of the trunk where they will encounter the rst hard layer from the ground surface. As to their number, when they are made of reinforced concrete, in many cases one of them is provided symmetrically in the same plane at either sideY of the trunk.V Y

Generally speaking, the nature of the ground is not uniform. The known pile only utilizes the hard bed of the ground reached by its lower end, and it is seldom that a hard layer found on the way is utilized. In my invention such an intermediate hard layer is utilized, and as the twigs B and B are attached to the trunk obliquely, the pile formed is hard to get into the ground and consequently possesses big supporting power.

In driving the pile, there are two opposite objects desired. Thatis to say, while it is hoped that the pile may sink easily during driving, it should not sink after driven. Some piles have spikes or projections on the surfaces of their trunks so as to sink down less in the final, stage of the driving operation. However, it is comparatively ineffective to prevent the sinking of the piles in spite of the great difficulty encountered in driving them.V But in driving my twigged pile, the difficulty does not occur during the process of driving, as the twigs B and B do not reach a hard layer until the lower end of the trunk reaches the last hard bed, when the final driving becomes diflicult simultaneously, and this very diliiculty of driving is utilized effectively as supporting DOwer Especially, a pile with the twigs B and B attached to the same point may be driven with the same easiness and at the same cost as a common pile till the twigs reach a hard layer where it shows great supporting power. My pile may be used in several kinds of foundations, such as for buildings, bridges, etc., exerting big vsupporting power.

And also due to its great supporting power, it

' is possible to design a special structure utilizing this pile. Figure 3 shows a special example of utilizing this pile in a culvert. In this example it is possible to make the piles with the same quantity 'of materials necessary to construct the bottom plate of the culvert in the usual manner, and piles after driven are connected with each other at the upper ends, showing suiiicient strength, so the foundation work of the culvert may be wholly saved. Also, when this pile is used for a retaining wall, the twigs resist oblique external force. Therefore, it shows great sup.- porting power as compared with common ones. l

`A1though my pile can be driven without difficulty till it reaches the last hard bed of the ground, it is none the less preferable to use a water 'jet to make the driving easy. In this case, it would be convenient if pipes are provided within the trunk A and the twigs B and B during the process of manufacturing the pile so as to allow water to pass through them.

Itis to be noted that the ends of the twigs or i arms B, B terminate in afiat bevelled surface B2 -and'that the underside B3 of each of these twigs or 'arms is also a flat surface, the two surfaces B2 and B3 'being at an acute dihedral angle so that a sharp chisel edge is formed at the lower end of each twig or arm. It is also to be observed that the reinforcing rods are so disposed in the concrete that certain of the rods, as C', extend longitudinally of the main pile and also of its twigs or arms and that across the body A and twigs or arms B, .B extends tie means C2 which is located justabove the junction of the at undersides B3 of these twigs or arms and the sides of the body A. By means of the angles formed between the surfaces B2 and B3 the device may be driven. int-o the ground with little or no tendency for the lower ends ofthe twigs or arms to flex outwardly from the body and break off since the tendency to produce such flexure due to the sides B3 is counteracted by the tendency to eX inwardly produced by the bevelled ends B2. Moreover, any excess of tendency as produced by the surfaces B3 is resisted by the tie means C2. Y

I claim: Y

1. A reinforced concrete pile having a body and a pair of arms extending downwardly and outwardly on opposite sides of the body from a point spaced above the lower end of said body,

said arms having at undersides and having their ends bevelled to form acute dihedral angles with said undersides whereby to form chisel edges at the lower ends of said arms. Y

AVV reinforced concrete pile having a body and a pair of arms extending downwardly and outwardly on opposite sides of the body from a point spaced above the lower end of said body, said arms having flat undersides and having their ends bevelled to form acute dihedral angles with said undersides whereby to form chisel edges at the lower ends of said arms, the reinforcing of said pile including tie means extending across said pile and arms closely above the junction of the sides of the pile body and undersides of the arms. Y

' SHIGEYUKI KANAMORI.

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