JPS6252083B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sand pile construction device used in sand drain construction methods and the like.

One of the construction methods for sand piles, such as the sand drain method, is to penetrate into soft ground while rotating a casing whose tip is closed with a flat bottom cover, then after filling the casing with sand, the bottom cover is opened. There is a construction method that involves pulling out the casing and leaving a sand column in the ground.

Conventionally, the casing for the above-mentioned sand drain method, as shown in Fig. 4, has a pivot point or the like on the inner surface so that the sand bag filled with sand can be discharged from inside the casing 1' into the ground without damaging the sand bag when it is pulled out. No protruding parts are provided, and therefore the pivoting part and the closing part of the bottom cover are provided to protrude from the outer periphery of the casing 1'. Further, a spiral cutting blade 2' for cutting into the ground is formed on the outer periphery of the casing 1' over almost the entire length, so that when the casing is rotated and excavation is performed to penetrate into the ground, the cutting blade 2' can be cut over almost the entire length of the casing. As the blades 2' dig into the ground, the pivoting and closing parts of the bottom cover act as resistance, resulting in excessive excavation resistance and often making it impossible to dig. Furthermore, in the process of filling sand into a casing that has penetrated the ground and then pulling it out, the spiral cutting blades are biting into the ground, making it difficult to pull them out in a straight line without rotating them. It must be pulled out while rotating slightly in the opposite direction to the digging direction.
For this reason, not only is it time-consuming to pull out the bag, but also the sand bag filled with sand may be cut or damaged due to rotation.

In view of the above-mentioned circumstances, the present invention does not equip the outer periphery of the casing with spiral cutting blades,
A plurality of chips cut in the rotational direction of the casing are attached to the bottom surface of the bottom cover of the casing, a pivot joint part of the bottom cover protruding from the outer periphery of the casing, and a plurality of chips cut in the rotational direction of the casing, respectively, and the pivot joint part on the outer circumference of the casing. and directly above the closing part, respectively.
A small fin is provided in the casing axis direction, the upper side of which is approximately the same height as the protruding height of the pivoting part and the closing part from the casing outer peripheral surface, and whose upper side slopes upward of the casing.
When penetrating the casing, excavation resistance is reduced by excavating the ground to a diameter larger than the casing diameter using the bottom surface of the bottom cover and the tips on the outside of the casing.
Another object of the present invention is to provide a sand pile construction device that allows the casing to be pulled out in a straight line without reversing the casing, thereby making sand pile construction easier and faster. be.

The configuration of the present invention will be described with reference to an embodiment shown in the drawings.

In FIGS. 1 and 2, reference numeral 1 denotes a cylindrical casing with a smooth curved outer surface, and a planar bottom cover 2 that opens only outward is attached to the tip of the casing 1. Reference numeral 3 designates a pivoting portion of the bottom cover 2, and 4 designates a closing portion, which are both provided to protrude from the outer circumferential surface of the casing 1, avoiding forming a protruding portion on the inner surface of the casing 1. A plurality of chips 6 are attached to the bottom surface of the bottom cover 2 and to the outer sides of the pivot portion 3 and the closing portion 4, respectively, so as to bite in the direction of rotation of the casing 1. In addition, the casing 1 of the pivot joint 3 and the closing part 4 is located directly above the pivot joint 3 and the closing part 4 on the outer peripheral surface of the casing 1, respectively.
A small fin 5 is provided in the direction of one axis of the casing, the upper side of which is approximately the same height as the protruding height from the outer circumferential surface and inclined upwardly of the casing.

The cylindrical casing 1 penetrates into the ground while being rotated, but the equipment for this purpose is well known and will not be illustrated or described here.

To explain the process of constructing a sand pile according to the present invention configured as described above, the tip of the casing 1 is connected to the bottom cover 2.
The casing 1 is rotated so that the bottom surface of the bottom cover 2, the pivot portion 3 and the closing portion 4 are closed.
The ground is excavated using a plurality of chips 6 attached to the outside of the excavator and penetrates to a predetermined depth. Next, a sand bag is suspended from the upper end opening of the casing 1 penetrated into the ground, and is filled with sand to form a sand column inside the casing 1. After that, when the casing 1 is pulled out, the bottom cover 2 is automatically opened because there is no protrusion on the inner surface of the casing, and the sand bag is directly discharged into the ground, forming a sand pile.

FIG. 3 shows the construction mode of the sand pile, in which A is the ground, a is the lower layer, a' is the silt layer, B is the sand pile, and C is the front steel sheet pile.

In the construction of the sand pile, chips 6 are attached to the bottom surface of the bottom cover 2 at the tip of the casing 1, and to the outside of the pivoting part 3 and the closing part 4 of the bottom cover 2 that protrude from the outer periphery of the casing 1. Since a larger diameter excavation is performed, the outer peripheral surface of the casing 1 does not dig into the ground, and the casing 1 is penetrated with less excavation resistance.

When the casing 1 is pulled out, the casing 1 does not dig into the ground.Furthermore, the fins 5 are flat plates in the axial direction of the casing 1, their upper sides are inclined upwards of the casing, and their area is small. A cut perpendicular to the ground is cut in advance of the pivoting part 3 and the closing part 4, and the casing is guided vertically in the axial direction, so that the casing 1 can be pulled out in a straight line without rotating with slight pulling resistance. Can be done. Therefore, the sand pile construction efficiency is greatly improved compared to the conventional construction using a casing provided with spiral cutting blades on the outer periphery. Incidentally, in the conventional construction method, it took 14 minutes to penetrate the casing and 9 minutes to pull it out, but with the present invention, it took 5 minutes to penetrate the casing 1 and 9 minutes to pull it out with the same sand pile construction. It became possible to shorten the time by 3 minutes. Furthermore, since the resistance required for penetrating and pulling out the casing 1 is small as described above, there is no possibility of work being impossible due to overload of the prime mover when the casing 1 is being excavated and penetrated, and the same is true when the casing 1 is being pulled out.

In short, the present invention provides a bottom cover pivoting part and a closing part that protrude from the outer peripheral surface of the casing in the diametrical direction at the tip of a casing that penetrates into the ground while being rotated, and the pivoting part and the closing part have a flat surface. In a sand pile construction device, a sand pile construction device is equipped with a shaped bottom cover that closes when the casing is press-fitted and opens to the outside when the casing is pulled out. A plurality of chips cut in the rotational direction of the casing are installed on the outer sides of the pivot joint and the closing part, respectively, and the casings of the pivot joint and the closing part are installed directly above the pivot joint and the closing part on the outer peripheral surface of the casing. By providing a small fin in the direction of the casing axis with an upper side that is approximately the same height as the protruding height from the outer circumferential surface and slopes upwards of the casing, when the casing penetrates, the ground is excavated to a diameter larger than the casing diameter, and the casing No digging into the ground on the outer surface,
This reduces excavation resistance, avoids overloading the prime mover, and shortens penetration time.Furthermore, since the bottom cover is flat, there is no risk of hole bending, as in the past. When pulling out the casing, it can be pulled out in a straight line and in a short time without rotating it, which not only significantly improves construction work efficiency, but also prevents the sand bag filled with sand from being cut or damaged. It is possible to perform sand pile driving without such inconveniences, and the chips attached to the bottom of the bottom cover, the pivot joint, and the outside of the closing part prevent wear on these parts and the outer circumferential surface of the casing. This brings about extremely useful novel effects such as significantly extending the life of the device.

[Brief explanation of the drawing]

The drawings show an embodiment of the sand pile construction device according to the present invention, in which Figure 1 is a front view of the casing, Figure 2 is a plan view of the same, and Figure 3 is an example of the sand pile construction mode. The sectional view shown in FIG. 4 is a front view of a conventional casing. 1... Casing, 2... Bottom cover, 3... Pivot joint, 4...
Its closing part, 5... small fin, 6... tip.

Claims (1)

[Claims] 1. A bottom cover pivoting part and a closing part are provided in the diametrical direction at the tip of the casing that penetrates into the ground while rotating, protruding from the outer peripheral surface of the casing, and a planar bottom cover is attached to the pivot part and closing part of the casing. In a sand pile construction device that is installed to close when press-fitting and open to the outside when pulled out, spiral cut blades are not installed on the outer periphery of the casing, and the bottom surface of the bottom cover and the pivot joint and closing A plurality of chips cut laterally in the rotational direction of the casing are attached to the outer side of the casing, and a plurality of chips are installed on the outer circumferential surface of the casing directly above the pivot joint and the closing part, respectively, of the pivot joint and the closing part. A sand pile construction device characterized by providing a small fin in the axial direction of the casing, the upper side of which is approximately the same height as the protruding height from the outer circumferential surface and slopes upward of the casing.