JPH10183616A - Pile anchor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce cost and improve the workability by forming a pile anchor main body with a tip side pipe having a small outer diameter and a rear end side pipe having a large outer diameter and by attaching a spiral blade to the side portion of the tip side pipe. SOLUTION: A pipe main body is formed by connecting a small-diameter tip side pipe 20 to a large-diameter rear end side pipe 30, and a spiral blade 21 is wound round the outer peripheral surface of the pipe 20 and a pile anchor 10 is constituted. Next, a cutting tooth 22 is formed at the tip of pipe 20, a lid body having thread ridge is provided at the end portion of the pipe 30, and the connection of a columnar member such as traffic sign pole is made possible. Next, the outer diameter of the spiral blade 21 is coincided with the outer diameter of the pipe 30 and this makes the driving easier. By doing this, the pile anchor can be used as foundation pile for a building or various anchors; and the cost can be reduced since the spiral blade is attached only to the tip portion and also the work efficiently can be improved because of light weight.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pile anchor for civil engineering construction having a spiral blade.

[0002]

2. Description of the Related Art As a pile anchor for civil engineering construction,
Conventionally, there is, for example, one shown in FIG. The pile anchor 1 is provided with a spiral blade (spiral) 5 on the entire side from a front end (lower end) 3 to a rear end (upper end) 4 of a straight pipe (straight steel pipe) 2. Reference numeral 7 denotes a lid for connecting to a driving jig, and reference numeral 8 denotes a cutting tooth. The pile anchor here is a pile that supports the load.
As well as can be used as an anchor against tension,
It is a building civil engineering material with versatile uses.

[0003] Such a pile anchor 1 having the spiral blades 5 has a large surface area with respect to the cross-sectional area, and therefore has excellent effects such as increasing the frictional force particularly on soft ground and reducing its own weight. Demonstrate. Moreover, since the driving is performed by rotating a driving jig (a hydraulic device or the like) attached to the lid 7, there is no environmental problem such as noise or vibration during the construction period.

[0004]

By the way, such a conventional pile anchor can be used in two ways, that is, when it is used as a foundation pile for construction and when it is used as an anchor against tensile force. That is, pile anchor 1
The spiral blade 5 is formed on the entire circumference from the leading end to the trailing end of the straight pipe 2 so that it can be used for various purposes. However, the formation of the spiral blade requires a special technique, and the forming cost is extremely high because the strength of the steel spiral must be ensured.

The conventional pile anchor 1 has the advantage of increasing the frictional force due to the large surface area of the helical blades 5, but it is heavy in weight, and sometimes it becomes difficult to drive the anchor manually. In some cases, work efficiency may be hindered, such as the need for a hydraulic device.

Accordingly, an object of the present invention is to further reduce the manufacturing cost of a steel anchor and to make the anchor driving operation easier.

[0007]

In order to achieve the above-mentioned object and to achieve the object, a spiral pile anchor according to the present invention comprises a steel pipe having a front end pipe having a small outer diameter and a rear end pipe having a large outer diameter. A single pile anchor body is made, and spiral blades are formed only on the side of the tip-side pipe.
In addition, in order to make the driving easier, the rotational diameter of the spiral blade may be substantially the same as the outer diameter of the rear end pipe.

[0008]

In the pile anchor according to the present invention, a thin pipe and a thick pipe are connected to form one anchor pipe. The outer diameter and length of the pipe are variable according to the purpose of use, but the tip end (lower side) is a thin pipe, the rear end side (upper side) is a thick pipe, and the lower thin pipe part has a spiral blade. Arrange the boards. That is, the spiral blade is not provided on the side surface of the rear end side pipe.

As a result, when the pile anchor is driven, the spiral blade of the tip end pipe enters the ground while rotating, and the driving can be performed in the same manner as the conventional pile anchor. The rear end side pipe has no spiral blades, so the total area of the blades is smaller than that of a conventional pile anchor.However, the spiral spiral blades on the distal end usually penetrate into a hard ground layer, By doing so, a force against tension can be secured, so that the functionality as a pile anchor can be sufficiently maintained.

On the other hand, since the rear end side pipe has no spiral blade, the frictional force at the time of driving is reduced, and the rotational force applied to the driving jig can be reduced. For this reason, driving by human power becomes easy, and a small hydraulic device can be used, so that work efficiency is improved. This is the same when removing an unnecessary pile anchor.

Further, since the spiral blade is not provided on the rear end side pipe, the overall weight is reduced and the transportation work and the handling at the site are facilitated. Further, since the mounting area of the spiral blade is reduced, the cost can be significantly reduced. Moreover, since the rear end side pipe is thick, the horizontal load applied after the driving is strong, and the reliability is improved.

The vertical dimension of the spiral blade, that is, the length of the tip side pipe is determined by the tensile force (in the case of an anchor) or the load (in the case of a pile) calculated with a safety factor, and from the surface layer to the hard ground layer. It is determined by the correlation of various conditions such as the depth.

According to the second aspect, the rotational diameter of the spiral blade is substantially the same as that of the rear end side pipe, so that the torque of the driving rotation can be reduced. If the rotation diameter of the spiral blade is smaller than that of the rear end pipe, the rear end pipe becomes difficult to enter, while if the rotation diameter is large, the cost increases and the weight increases. Of course, the diameter may be freely set according to various conditions such as the ground.

[0014]

Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 to 3 show an example of a pile anchor according to the present invention. This pile anchor 10
The front-end side pipe 20 and the rear-end side pipe 30 are connected to form a single pipe body, and a spiral blade 21 is wound around the outer peripheral surface of the front-end side pipe 20.

The connection between the front end pipe 20 and the rear end side pipe 30 uses, for example, a conical joint 32 whose top is cut off. The joint 32 is used to insert and weld the front end pipe 20, or to cut a thread inside in advance and screw and connect the front end pipe 20.
Instead of using the joint 32, the connecting inclined portion between the front end pipe 20 and the rear end pipe 30 may be formed by drawing.

The cutting edge 22 is formed at the tip of the tip side pipe 20 by press drawing or the like. The shape and number of the cutting teeth 22 are not limited. Alternatively, the cutting teeth 22 may be separately formed and fixed by appropriate means such as welding or bolts.

A lid 33 is provided at the end of the rear end side pipe 30 as shown in FIG. In this embodiment, a screw thread 39 is cut in the lid 33 so that another columnar member can be connected. This is for the purpose of connecting a pole of a traffic sign, for example. When the columnar member or other members are not connected, the lid 33 may be closed using a flat plate having no hole. The cover 33 is provided with a bolt hole for fixing the driving jig, or a member for fixing the jig is fixed to rotate.

Above the rear end side pipe 30, a plurality of holes 35 may be formed as necessary. This hole 35 functions as a drain. Although not shown, when the hole 35 is provided, it is desirable to provide a drainage hole corresponding to an appropriate position of the joint 32.

The pile anchor shown in this embodiment is of the smallest type, but the dimensions of each part are as follows. The length and the outer diameter of the distal end pipe 20 are each H
1, W1, the length and outer diameter of the rear end side pipe are H2, W
2. When the length (height) of the joint 32 is H3, the length of the cutting teeth 22 is H4, and the pitch of the spiral blade 21 is H5, for example, H1 = 730 mm, W1 = 22 mm, and H2 = 72.
0 mm, W2 = 42.7 mm, H3 = 30 mm, H4 =
20 mm and H5 = 120 mm.

Although these dimensions can be changed depending on the purpose of use, W1 can be set, for example, up to a maximum of 267.4 mm, and W2 can be set, for example, a maximum of 318.5 mm.

The number of spiral windings in this embodiment, where the pitch of the spiral blades 21 is 120, is 1.5 turns, but the spiral pitch can be freely changed in design according to the thickness and length of the steel pipe. However, the outer diameter of the spiral is
It is desirable to match the outer diameter W2 to zero. This is for facilitating the driving.

The pile anchor 10 can be used not only as a foundation pile or various anchors of a building, but also as a pole for various signs as shown in FIG.
The spiral wing plate 21 at the tip bites into the hard ground to firmly support the pole, and to reliably prevent the pole from tipping over due to wind.
In addition, since the spiral blade 21 is provided only at the tip end, the cost is low, the weight is low and the working efficiency is improved.

When the pile anchor 10 according to the present invention is driven into soft ground or used as a foundation pile for supporting a larger load, the length of the tip side pipe 20 is increased to increase the number of spiral turns. It is desirable that the relationship between the length H1 of the front end pipe 20 and the length H2 of the rear end pipe 30 be H1 ≦ H2. This is because the cost is suppressed and the weight is reduced while ensuring sufficient functionality.

[0024]

As described above, according to the pile anchor according to the present invention, the manufacturing cost of the steel anchor is reduced by the shape improvement, and the driving operation is made easier.

[Brief description of the drawings]

FIG. 1 is an overall front view showing an example of a pile anchor according to the present invention.

FIG. 2 is a partially enlarged view showing a right side surface of the pile anchor shown in FIG.

FIG. 3 is an enlarged sectional view taken along line AA of FIG. 1;

FIG. 4 is a view showing an example of use of a pile anchor according to the present invention.

FIG. 5 is a view showing a conventional pile anchor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Pile anchor 20 Front end pipe 21 Spiral blade 22 Cutting teeth 30 Rear end side pipe 32 Joint 33 Lid 35 Hole

Claims (2)

[Claims] 1. A pile anchor formed by forming a spiral blade on a side of a straight steel pipe, wherein the steel pipe has a front end pipe having a small outer diameter and a rear end pipe having a large outer diameter. A pile anchor, wherein the spiral blade is formed from a lower end to an upper end on a side portion of a tip side pipe. 2. The rotation diameter of the spiral blade is substantially the same as the outer diameter of the rear end pipe.
The described pile anchor.