JPS59109616A - Steel pipe pile - Google Patents

Abstract

PURPOSE:To stably penetrate a steel pipe pile into the ground at low cost by a method in which an excavating blade is projectionally provided to the lower end of the steel pipe and a spiral blade is also projectionally provided to the periphery from the lower end to the upper part of the pile. CONSTITUTION:A rotary push driver attached to the upper end of the pile body 1 is driven to penetrate the pile body 1 into the ground while turning the body 1. The straight penetration of the pile body 1 into the ground is maintained by the straight tube part of a distance of (a) from the lower end to the spiral blade 4 of the pile body 1, and the penetration of the pile body into the ground is promoted by the advancement of the spiral blade 4 into the ground.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a steel pipe pile that penetrates underground without noise or vibration.

Conventionally, in order to bury steel pipe piles underground without noise or vibration,
After drilling a burial hole using an auger, the steel pipe pile is inserted into the hole, or the steel pipe pile itself is provided with spiral wings over most of its length, and this is press-fitted while rotating. There is. However, the former method uses an auger, which makes construction difficult and expensive, and the latter method uses spiral blades, so
The disadvantage is that the price of steel pipe piles is extremely high.

The present invention was made in order to improve the above-mentioned drawbacks of conventional steel pipe piles.The present invention has been made in order to improve the drawbacks of conventional steel pipe piles. By protruding from the spiral blade, a substantial linear guide portion of the required length is formed in the lower part of the spiral wing, and penetration into the ground can be performed stably with a simple operation of rotational press-fitting. The purpose of the present invention is to provide a steel pipe pile that has a simple structure, can be manufactured at low cost, and has a large supporting capacity.

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

In Figures 1 and 2, 1 is a pile body made of steel pipe membrane, a bottom plate 2 is fixedly installed at the lower end of the pile body, and several digging blades 3, 3, etc. are protruded through the bottom plate 2. ing. And the pile body 1
At the lower part of the pile body 1, a spiral wing 4 is protruded in a short section extending over the outer circumferential surface of the pile body 1 at an upper position separated by a required distance l from the lower end of the pile body 1. In the drawings of the embodiment, the spiral blade 4 is formed continuously over about -0 turns, but the number of turns may extend to several turns, and the spiral blade 4 is divided into discontinuous sections. It may be formed so as to form a spiral shape as a whole. In addition, from the spiral blade 4 to the pile body 1
The part spanning the distance l to the lower end of is the part that plays an important role in guiding the steel pipe pile to move straight when it penetrates, so from that point of view alone, it is advantageous to make the distance l as long as possible. However, since the spiral blades 4 cut into the ground and promote the penetration of the entire steel pipe pile, if they are located above the pile body 1, the penetration performance will be reduced accordingly. Therefore, the location of the spiral blades 4 needs to be determined from the viewpoint of both straight-line stability and penetrability of the steel pipe pile. Therefore, the distance l from the lower end of the pile body 1 to the helical blade 4 is determined from the results obtained through experiments, etc.
It was found that for the diameter d of the pile body, the range of x=-La-2d was good, and especially around 1=d was the best.

The steel pipe pile of the present invention is constructed as described above, and during construction, a rotary pushing drive device (not shown) is attached to the upper end of the pile body 1, and the drive device drives the pile body 1 while rotating it. If this is done, the excavation will proceed with the excavation blade at the lower end, and the straightness of the excavated material into the ground will be maintained by the straight pipe portion of the distance l from the lower end of the pile body 1 to the helical blade 4. Then, the penetration of the pile is promoted by the incision of the spiral blade 4 into the ground. After the steel pipe pile has penetrated, the pile body 1 may be filled with concrete or the like to further increase the strength and rigidity of the steel pipe pile.

FIG. 3 shows another embodiment of the lower end portion of the steel pipe pile of the present invention. In the embodiment described above, the lower end of the pile body 1 is completely covered by the bottom plate 2, but
In the illustrated embodiment, the bottom plate 2 is formed into an annular shape, and a through hole 5 into the pile body 1 is formed. By providing such a through hole 5, the soil dug by the excavating blades 3, 3, etc. will retreat from the through hole 5 into the pile body 1 as it penetrates the pile body 10, so that the soil dug by the excavation blades 3, 3, etc. will retreat from the through hole 5 into the pile body 1. It has less resistance and is especially suitable for construction on hard ground.

In addition, in the steel pipe pile of the present invention, the spiral blades 4, the bottom plate 2, and the digging blades 3 may be directly provided on one long pile body 1, but as shown in FIG. The section may be provided in another steel pipe a having the same diameter as the pile body 1, and the steel pipe a may be joined to the pile body 1 by welding at the position already shown by the chain line in FIG.

As explained above, the steel pipe pile of the present invention has a digging blade protruding from the lower end of the pile body made of steel pipe, and has a winding or several windings on the outer peripheral surface at an upper position at a required distance from the lower end. Since the helical blades are installed protrudingly, the supporting area of the steel pipe pile is significantly increased, and even small-diameter piles can obtain large soil bearing capacity and have good penetration. Because the spiral blades are formed in a single section, they provide good straight-line stability during penetration, and because the length of spiral blades is significantly shorter than conventional ones, steel pipe piles can be manufactured at low cost and are easy to construct. It has many excellent advantages such as being easy and economical.

[Brief explanation of drawings]

FIG. 1 is a side view showing one embodiment of the steel pipe pile of the present invention, FIG. 2 is a bottom view of the same, and FIG. 3 is a side sectional view of essential parts showing another embodiment of the steel pipe pile of the present invention. 1...Pile body 2...Bottom plate 3...Drilling blade 4...Spiral blade 5...Through hole patent applicant Notice 1) Plowing Figure 1 Figure 3

Claims (1)

[Claims] A digging blade is provided protruding from the lower end of the pile body of the steel pipe membrane, and a spiral blade is provided protrudingly over one or several turns on the outer circumferential surface at a position above the lower end at a required distance.
Steel pipe pile.