JPS63161219A - Foundation pile and its construction - Google Patents

Abstract

PURPOSE:To construct a foundation pile without causing noise and vibration by a method in which a foundation pile having excavating screwed blades on its tip and periphery is rotationally inserted into the ground until the tip of the pile reaches the bearing ground, and the foot of the pile is fixed as it is. CONSTITUTION:The tip of a foundation pile 1 is shaped into a conical drill form, and a screwed excavating blade 2 is integrally formed on the periphery of the pile 1. A screwed portion 4 to be connected with attachment is provided for the basal end 1b of the pile 1, and a cement-milk outlet 3 is provided slightly upwards in the opposite direction of the turning direction on the head 1a of the pile 1. The end 1 is connected with the rotary driver and rotationally inserted into the ground, and when the head 1a reaches the bearing ground, the rotation of the pile 1 is stopped and cement milk 7 is injected through an injection tube 6 from the end 1b into the pipe of the pile 1 and hardened. The blade 2 serves as a friction plate after being driven and can exhibit its stable bearing force.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a foundation pile that is built into the foundation ground as a soil reinforcement measure, and a method for erecting the foundation pile.

Conventional technology Foundation piles that are built into soft ground to reinforce the foundation ground are conventionally used, for example, by driving foundation piles such as concrete piles directly into the ground, or by drilling holes using an auger screw, etc., and then inserting concrete or steel pipes into the holes. Foundation piles made of steel were inserted and embedded.

C. Problems that the invention aims to solve: The method of directly driving concrete piles into the ground is accompanied by strong vibrations and noise, which can damage surrounding buildings and property in densely populated residential areas and cause a great deal of inconvenience to residents. Not only,
Requires large-scale driving equipment. Also, drill a hole in advance,
The method of inserting the center pile requires two different types of large machines: one to drill the hole for insertion and the other to insert the foundation pile. In this case, the cement milk overflowed and the post-processing was very troublesome. In addition, the pile itself has a disadvantage in that its supporting capacity is poor because the outer peripheral surface has a uniform diameter over its entire length.

2. Means for solving the problem In view of the above-mentioned conventional drawbacks that occurred when erecting foundation piles, the present invention enables the erecting work to be completed without vibration or noise and with only one type of machine. The foundation piles built in the earth exhibit high bearing capacity comparable to friction piles, and can be used without any problems even in densely populated areas. The second invention consists in that a screw blade-shaped digging blade is provided continuously or intermittently in the longitudinal direction on the tip and outer periphery of the pile main body, and the second invention is provided with a screw blade-shaped digging blade on the tip and outer periphery. A method of building foundation piles in which a foundation pile that is integrally installed is erected on the foundation ground, rotated and lowered into the ground, and when the tip reaches the supporting ground, it is anchored in that state. .

E. Since a screw blade-like digging blade is integrally provided at the working tip and outer periphery, the foundation pile is screwed into the foundation ground smoothly by applying rotation with the tip facing straight down. Furthermore, the erected foundation piles have screw blade-like digging blades that spread toward the outer periphery and bite into the ground, acting as an anchor like a friction plate, and the frictional force ensures sufficient supporting force. Ru.

Example First, the foundation pile according to the present invention will be explained based on the drawings.
The foundation pile main body 1 is made of a steel pipe that is hollow inside and galvanized on the entire surface, and the tip is formed in the shape of a closed conical drill, and a screw blade-shaped digging blade 2 is provided on the outer periphery. It is integrated. Slightly above the head portion 1a, a cement milk outflow hole 3.3 is bored in a direction opposite to the direction of rotation with respect to a tangent to the inner wall of the steel pipe. It is desirable that the outflow hole 3 be provided slightly upward to prevent clogging during excavation. Furthermore, on the circumferential surface of the pile body 1,
Screw blade-shaped digging blades 2a, 2b and ee are provided intermittently with two turns at approximately every 50 cm so that the diameter gradually becomes larger toward the base end side. A threaded portion 4 for connecting various attachments is formed on the base end portion 1b.

In order to erect the foundation pile configured in this way, a back auger, track auger, piling machine, etc. is used, and the rotary drive unit 5 and the base end 1b of the foundation pile are connected with an attachment to erect the foundation ground. Stand up and then apply rotation. As a result, the foundation pile is screwed into the soil by the digging blade 2 provided around the head portion 1a, and descends under its own weight. and 5
After descending about 0cm, the drilling blade 2 is located above it.
The digging blade 2a, which is in contact with the ground surface and has a larger diameter than the hole drilled by the digging blade 2 provided on the head portion 1a, also rotates to dig in a spiral shape and expand the hole. Further increase the diving force and continue descending. Furthermore, the excavating blades 2b, 2c, etc. located above the excavating blades 2b, 2c, etc., dig down, and the diameter gradually increases as the excavating blades 2b, 2c, . . . When the head part 1a reaches the foundation ground, the rotation is stopped, the base end part 1b is removed from the rotary drive part 5, a cement milk injection pipe 6 is connected instead, and cement milk is forced into the pipe body. The press-fitted cement milk 7 flows out from the spout hole at the tip and wraps around the foundation pile, while the excess is pushed up in two directions. After confirming that the entire surrounding space of the foundation pile is filled with cement milk 7, the injection of cement milk is stopped and solidification is waited.

In this way, the rooting is completed and the erection work is completed.

The erected foundation piles are intermittently provided with excavation blades 2.
2a, 2b, . . . play the role of anchors as friction plates, and the injected cement milk 7 permeates into the soil of the ground and solidifies, thereby ensuring a large supporting force. Moreover, during construction, since the foundation piles are simply rotated, there is no need to introduce large-scale machinery, and no vibration or noise is generated. In addition, since the pile itself is no different from the free-standing type, the excavation blade only needs to be able to withstand one-time use, and it can be made of an inexpensive material as a consumable item, and equipment such as an auger screw is not required.

In this embodiment, a case has been described in which cement milk is injected during construction, but it is not necessarily necessary to inject cement milk depending on the ground condition, and if it is not injected, a cement milk outflow hole is not required. In addition, the pile body is galvanized to increase its durability, and digging blades are provided intermittently to reduce costs. It may be provided continuously up to the end side, or the diameter of the cutting blade may be made constant.

In short, a screw blade-like digging blade is installed on the outer periphery of the pile body.
As a result, the pile itself is sunk into the ground by rotation, and after being sunk, the digging blade extends out to the surrounding area, thereby ensuring stable supporting capacity. , length etc. will be determined as appropriate depending on the ground conditions.

G. Effects According to the present invention, foundation piles can be erected without vibration and noise, and the work can be completed with a simple operation of applying rotation. Furthermore, the excavation blade used for excavation acts as a friction plate after erection, providing a large and stable supporting force comparable to friction piles.

Therefore, it can be used safely even in densely populated areas, and the practical benefits of carrying out work at low cost and with high reliability are great.

[Brief explanation of the drawing]

1+4 is a perspective view showing the foundation pile of the present invention, FIG. 2 is a perspective view showing the tip of the foundation pile, FIG. 3 is a sectional view taken along line A-A at the tip, and FIG. 4 is the construction Illustration of the work,
FIG. 5 is an explanatory diagram showing the state of the ground into which cement milk has been poured, and FIG. 6 is an explanatory diagram showing an example of a modification of the foundation pile. 1...Pile body, 1a...Head part, 1b/e base end part 2
．． 2a, 2b, 2c...Flash cutting blade, 3...Outflow hole, 4...
Threaded part, 5-Rotation drive part, 6-Fist cement milk injection tube, 7-Red cement milk

Claims (1)

[Claims] 1. A foundation pile, characterized in that a screw blade-like excavation blade is integrally provided on the tip and outer circumference of a pile body made of a vertically long steel pipe, either continuously or intermittently in the longitudinal direction. 2. The foundation pile according to claim 1, wherein the diameter of the excavation blade gradually increases from the tip to the base end of the pile body. 3. A foundation pile with a screw blade-like digging blade integrally installed on the tip and outer periphery is erected on the foundation ground, rotated and lowered into the ground, and when the tip reaches the supporting ground, it remains as it is. A method for erecting foundation piles characterized by anchoring them with roots. 4. The foundation according to claim 3, wherein the root stopper causes the cement milk injected from the base end of the foundation pile to flow out from the tip, fill it so as to surround the pile, and solidify. How to erect piles.