JPH057310Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention is used in the technical field of drain materials that are driven into the ground with a mandrel in order to extract moisture from soft ground and improve the ground. In particular, it relates to an anchor attached to the lower end of a drain material.

[Conventional technology]

As a method of removing water from soft ground and strengthening the ground, a belt-shaped drain material is driven vertically using a mandrel, and by applying pressure to the soft ground by, for example, embanking earth and sand on the ground, water is removed through the drain material. There is a known method of pushing it to the surface.

When driving this type of drain material into the ground, it is necessary to prevent earth and sand from entering the mandrel through the gap between the opening at the bottom end of the mandrel and the drain material attachment part, and when pulling out the mandrel. An anchor is conventionally attached to the lower end of the drain material in order to ensure that the drain material remains in a defined driving position through resistance.

As an anchor for this purpose, there is a conventional one disclosed as a "tip member" in Japanese Patent Publication No. 56-4683, for example. This tip member (anchor) is shaped into an arrowhead shape and has a shape that is in close contact with the lower end of the mandrel. Therefore, when driving the drain material, it penetrates underground with low resistance, which is highly effective. On the other hand, when the mandrel is pulled out, the anchor tries to adhere to the mandrel or stay in that shape, and the resistance area (horizontal projected area) becomes small, making it impossible to obtain sufficient resistance. As a result, there is a problem in that the anchor cannot fully fulfill its role as an anchor and rises together with the mandrel to a certain level above the predetermined driving depth. This tendency is particularly strong in soft ground.

[Problem that the invention attempts to solve]

The present invention solves the above-mentioned problems with conventional synthetic resin anchors, and provides an anchor that provides low resistance when driving the mandrel into the ground and high resistance when pulling it out. be.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention is designed to fix the drain material to the center of the upper surface of the horizontal flat plate-shaped anchor part made of synthetic resin, which is attached to the lower end of the drain material that is driven into the ground by a mandrel. The anchor part has a flat plate shape with a uniform thickness, and a metal plate is provided on the upper surface of the central part near the mounting part to provide rigidity at the central part. The rigidity is small and the tip part remote from the attachment part is flexible.

The synthetic resin is not particularly limited in its type, but in order to increase its strength, it is preferably molded from high-density polyethylene or a material having an equivalent strength.

If the metal plate is provided with a slit for the attachment part in its center, it will be easy to manufacture and easy to attach. On the other hand, if the metal plate is integrally formed with the anchor part, there will be an advantage that it will be easier to handle.

Furthermore, especially in soft ground, when the anchor part is deformed during driving, it may come into close contact with the mandrel and may not return to its original shape when pulled out. If a protrusion is provided on the upper surface of the part, the effect will be remarkable.

[Effect]

With the above-mentioned anchor, when driving, the tip part deforms into a shape along the lower end of the mandrel due to the resistance of the ground, reducing the driving resistance, so the anchor is prevented from being damaged, and when pulled out. In the event, the tip returns to its original horizontal state due to its elastic restoring force and receives high resistance from the ground over a large area, so that the anchor remains reliably at the predetermined driving position.

〔Example〕

Embodiments of the present invention will be described below based on the accompanying drawings.

The anchor of the embodiment shown in FIG. 1 is made of synthetic resin, especially high-density polyethylene, which has excellent strength and flexibility, and is integrally formed with a horizontal plate-shaped anchor part 1. Central part 1
1 and a plate-shaped mounting portion 2 that stands vertically. As shown in FIG. 2, the lower end of the drain material 3 is fixed to the attachment portion 2 with staples 31 or the like and inserted into the opening 41 at the lower end of the mandrel 4.

In this embodiment, the anchor part 1 is thick at the center part 11 near the attachment part 2 and has high rigidity, and the tip part 12 is thick and has high rigidity.
It is formed to be thin, low-rigidity, and flexible. In order to have such rigidity characteristics, the anchor part 1 of this embodiment has a central part 11 and a distal end part 1.
2 are made into a flat plate shape with the same thickness and uniformity, and a hole 51 for inserting a mounting part is formed on the upper surface of the central part 11.
A metal plate 4 having a diameter is arranged. The metal plate 5 reinforces the central part of the anchor part during use, but there is the option of not using it if reinforcement is not particularly required depending on the ground. Note that the metal plate may be molded integrally with the anchor portion.

If a drain material is fixed to an anchor having such an anchor part and driven into the ground using a mandrel, the tip end 12 of the anchor part will receive resistance from the ground during the driving process, as shown at 12' in Fig. 2. The shape is curved upward to cover the lower end of the mandrel 4, thereby reducing the resistance received by the anchor part and also preventing dirt and the like from entering the opening 41 of the mandrel. And the center part 1 of the anchor part
1 has high rigidity and can withstand resistance from the ground.

On the other hand, when the mandrel is pulled out, the tip 12 of the anchor part 1 tries to return to the horizontal state due to its own elastic restoring force, and receives downward resistance from the ground, so it bends slightly downward from the horizontal position. 12'' in Figure 2. Therefore, the resistance received from the ground is large, and the anchor will reliably stay at the predetermined driving depth position.

[Effect of idea]

As described above, according to the present invention, sufficient strength is ensured near the central part of the anchor part to withstand resistance during driving, and the tip part has flexibility, so the lower end of the mandrel It flexes along the shape of the anchor, reducing resistance during driving, which helps prevent anchor breakage. Furthermore, when the tip is pulled out, the tip deforms in the opposite direction to that described above, so it receives sufficient resistance and can remain at a predetermined driving position, contributing to improved reliability. Moreover, since it has a simple shape, it is easy and inexpensive to manufacture.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of an anchor according to an embodiment of the present invention, and FIG. 2 is a longitudinal sectional view showing the anchor of FIG. 1 in use. 1...Anchor part, 11...Central part, 12,1
2', 12''...Tip part, 2...Mounting part, 3...Drain material, 4...Mandrel.

Claims (1)

[Claim for Utility Model Registration] A horizontal flat plate-shaped anchor made of synthetic resin that is attached to the lower end of the drain material that is driven into the ground by a mandrel, and stands vertically at the center of the upper surface for fixation to the drain material. For those with a plate-shaped attachment part, the anchor part has a flat plate shape with a uniform thickness, and a metal plate is provided on the upper surface of the central part near the attachment part, so that the rigidity is high in the central part, and the anchor part is in the form of a flat plate with a uniform thickness. An anchor for drain material characterized by having low rigidity and flexibility at the tip.