JPH0262648B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for burying steel pipe piles in soft ground.

In general, the foundations of houses are constructed using independent foundations, cloth foundations, or solid foundations, and there is no problem with good quality ground, but recently residential areas with good quality ground around large cities have been heavily developed, and in recent years It is becoming more and more common for houses to be built on soft ground that has not yet been built, and with the above-mentioned general foundation structure, as time passes, houses tend to sink and deform due to uneven subsidence of the ground. Accidents that cause trouble occur frequently.

Improvement methods for such soft ground include the sand pile method, plastic board drain method, preloading method, and cement-lime method. , friction pile method and support pile method.

However, all of these construction methods are used for large-scale construction works on wide sites, and are designed to support large loads, and are used as foundations for ordinary houses with small top loads.
It is difficult to use due to construction scale, load conditions, economic efficiency, etc.

The current construction method is to use wooden piles, small-diameter concrete piles, or small-diameter steel pipes.
Although it supports the upper load, there are problems with noise and vibration when constructing in densely populated residential areas, and if the supporting ground is deep, the piles will be long, making it uneconomical.

The present invention improves the drawbacks of the conventional construction methods as described above, and is particularly suitable for construction in densely populated residential areas.
The aim is to improve the ground by constructing it in soft ground, and to provide a method for embedding steel pipe piles that have sufficient strength and bearing capacity as a foundation. As the pile rotates, the excavating blade at the tip of the pile excavates and softens the earth and sand at the tip, while the rotational biting force of the large-width helical blades that protrude from the outer circumferential surface of the pile is increased. The feature is that the steel pipe piles are screwed down to a predetermined depth by screwing. According to the present invention, the pile is pressed into the ground while rotating, the excavation blade excavates and softens the earth and sand at the tip of the pile main body, and a large spiral blade with the width of a wing is inserted into the unexcavated earth and sand on the side of the pile. As a result of screwing in like a notch, the bearing capacity of the soil acts as a reaction force on the top of the helical blade, and by applying rotation to the pile body, it is easy to screw in the direction of propulsion without the need for pushing force. Excavation at the tip of the pile The softened soil equivalent to the volume of the pile is pushed out to the side of the pile, compressing the soil on the side of the pile, compacting the ground, and allowing the pile to be driven and deposited without soil removal. Then, the compressed earth and sand volume on the side of the pile tightens the pile and acts effectively as a frictional force on the sunken pile, and together with the spiral blades having a large wing width, a large supporting force is obtained.

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

Fig. 1 is a side view showing an embodiment of a steel pipe pile used in the present invention, and Fig. 2 is a bottom view of the same. It is fixedly installed, and digging blades 4, 4 are provided to protrude downward from the bottom plate 2. Moreover, a spiral wing 3 for screwing in a pile with a large wing width is provided protrudingly provided at the lower end of the pile main body 1 along its outer peripheral surface.
As shown in the drawing, the spiral blade 3 has an outer diameter that is approximately twice to more than twice the outer diameter of the pile body 1, and is continuously formed over approximately one turn. Further, the pitch of the spiral blade 3 is selected to be approximately one-fourth of the outer diameter of the spiral blade 3.

The construction method of the present invention uses the above-mentioned steel pipe pile, and for its construction, a rotational pushing drive device (not shown) is attached to the upper end of the pile body 1,
By this drive, the pile main body 1 is rotated and pushed into the ground.

First, a steel pipe pile is erected on the ground, and is pushed into the ground while being rotated by a drive device as if screwed into the pile. As a result, the excavation blade 4 at the lower end excavates and softens the earth and sand at the tip of the pile to make it fluid, and the helical blades 3 for screwing in piles with a large wing width protruding from the outer peripheral surface of the pile body 1 are attached to the excavated earth and sand. The steel pipe pile is forced into the ground, and is propelled by rotation using the soil composition as a reaction force, compressing and displacing the fluidized earth and sand against the side of the pile, and screwing the steel pipe pile into the ground.

Therefore, the steel pipe piles are laid without soil removal, and the ground around the piles is consolidated.

As explained above, the steel pipe pile used in the present invention has a large helical wing for screwing into the pile protruding from the lower end of the pile body, the width of which is approximately twice the outer diameter of the excavation blade and the pile body. Because of this structure, the excavation blade softens and fluidizes the soil, and the wide spiral blades bite into the soil, making it possible to sink the pile simply by rotating the pile with a slight pressing force. It can be made efficiently and easily, and since the structure is extremely simple, it can be manufactured at low cost. In addition, since a spiral blade with a wide wing width is used, a large supporting force corresponding to the area of the spiral blade can be obtained, and it is highly effective when applied to foundation piles for houses, etc. on soft ground. The burying can be done extremely simply by rotating and pressing steel pipe piles directly into the ground, without noise or vibration, and is particularly excellent as a foundation pile construction method for houses built on soft ground. .

[Brief explanation of the drawing]

FIG. 1 is a side view showing one embodiment of a steel pipe pile used in the present invention, and FIG. 2 is a bottom view of the same. 1...Pile body, 2...Bottom plate, 3...Spiral blade, 4
...Drilling blade.

Claims (1)

[Claims] 1. A bottom plate is fixed to the lower end of the pile body made of steel pipe, a digging blade is provided on the bottom plate, and a wing width having an outer diameter of approximately twice the outer diameter of the pile body is attached to the outer peripheral surface of the lower end of the pile body. A steel pipe pile with a large helical blade for screwing the pile protruding over almost a full turn is pushed into the ground while rotating as if screwed into soft ground, and the excavation blade at the lower end removes the earth and sand from the tip of the pile body. After excavating and softening, the spiral blades dig into the unexcavated earth and sand on the side of the pile, and while the pile body is rotated and propelled using the soil's bearing capacity as a reaction force, the excavated and softened earth and sand is pushed out and compressed on the side of the pile. A steel pipe pile burying method characterized by screwing the pile body into the ground.