JPS5810531B2 - Bashiyochi Concrete Dodomekouhou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an earth retaining method using cast-in-place concrete.

Although various methods have been developed as earth retaining methods for constructing underground walls, the object of the present invention is to provide a method for constructing earth retaining walls without noise or vibration.

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

In the figure, A indicates an excavator.

This excavator A includes a self-propelled truck 1, a league mast 2 vertically supported by the truck 1, a drive device 3 attached to the leader mast 2 so as to be able to rise and fall, and a drive device 3 that can be freely attached to and detached from the leader mast 2. and an earth auger 4 connected to the earth auger 4.

The above-mentioned earth auger 4 is hollow, and the screw 5 provided spirally around its outer periphery is notched along the center line of the earth auger 4 in a range from the lower end to the upper end, as shown in FIG. ing.

The notch 8 has an arcuate shape approximately equal to the radius of curvature of the screw 5.

Therefore, of the two earth augers with the same structure, one
When the book is stopped and the other one is moved parallel to it, part of the screw of the moving earth auger will fit into the above-mentioned notch 8 and move, causing mutual interference. do not have.

Further, the earth auger 4 has a conical radius lid 7 attached to its tip so as to be openable and closable.

When the earth auger 4 penetrates into the ground, this cover 7 is closed by the resistance received from the ground, but when it is pulled out in a direction away from the ground, it is opened by its own weight.

In FIG. 1, reference numeral 9 denotes a hopper supported by the drive device 3, into which the fresh concrete in the container 11 lifted by the arm 10 of the crane is poured into the hollow part of the earth auger 4. It is designed to allow concrete to flow down.

Next, a method for constructing an earth retaining wall using the excavator A described above will be explained.

First, the upper end of one earth auger 4 is connected to the drive device 3 of the truck 1, and the ground auger 4 is erected perpendicularly to the ground surface B, and excavation is performed while being rotated.

When the earth auger 4 reaches a predetermined depth through the above-mentioned excavation, the rotation of the earth auger 4 is stopped, and the notch 8 is directed in the direction in which the earth retaining wall construction is proceeding.

Next, the earth auger 4 and the drive device 3 are uncoupled, the cart 1 is moved appropriately, and the second earth auger 4 is connected.
' is connected to the drive device 3, and the earth auger 4 buried earlier is
A part of the screw is fitted into the notch 8 and rotated in the same manner as described above to excavate to a predetermined depth.

In this case, the notch 8 of the earth auger 4 in the first order is in the shape of an arc with a radius of curvature approximately equal to the radius of curvature of the screw 5, so the earth auger 4' in the second order is parallel to the earth auger 4 in the first order. As long as they are excavated and entered, there will be no interference with each other.

When the excavation by the earth auger 4' of the next order is completed in this way, the notch 8'
Point it in the direction of progress of constructing the retaining wall (see the entrance in Figure 3).
.

After completing the excavation by the two earth augers 4 and 4' in this way, the upper end of the earth auger 4 in the preceding order is connected to the drive device 3, and the fresh concrete is poured from the container 11 into the ground using the hopper 9. The earth auger 4 is inserted into the hollow part, and at the same time, the extraction of the earth auger 4 is started.

When the earth auger 4 is pulled up slightly, the lid I at the tip opens, and ready-mixed concrete is poured into the hole a through the open part.

When the earth auger 4 is gradually pulled up, the excavated soil stuck between the screws 5 is also pulled up, but since the excavated soil will remain in the notch 8, it is necessary to pull out the earth auger 4. As a result, a hollow circular hole a is formed, and as the hole a is filled with fresh concrete, a concrete column C having an arcuate recess in the length direction is formed (No. (See Figure 3).

Next, the pulled out earth auger 4 is buried behind the next earth auger 4' in the same way as in the case described above, and the earth auger 4' is pulled out and the concrete pillar C that was formed earlier is buried. Concrete column C that partially overlaps the recess
′ is formed.

Since both e and e' are desirably connected to each other, the subsequent concrete column C' is formed before the previous concrete column C is hardened.

Note that it is desirable to insert reinforcing core materials d, d' such as H-shaped steel into each concrete column e, e' in an unhardened state in order to reinforce the column row.

By repeating the above steps, the concrete columns C are overlapped and connected to each other in the arc-shaped recess.
, e' will be constructed.

Since the construction method of this invention is as described above, the hole after pulling out the earth auger is circular, and the concrete column formed by pouring fresh concrete into the hole also extends in the length direction. An arc-shaped recess is formed.

Since the concrete columns formed one after another fit into the recesses and overlap, an earth retaining wall with excellent water-blocking properties can be obtained.

However, since each concrete pillar is integrated by overlapping each other, it is stronger than a single concrete pillar lined up.

In addition, the notch provided in the screw of the earth auger has an arc shape with a radius of curvature that is approximately equal to the radius of curvature of the screw, so even if two earth augers are embedded close together, they will not interfere with each other. Excavation and extraction can be carried out smoothly without any interference.

Furthermore, since this invention does not apply blows or vibrations, it is possible to construct earth retaining walls without noise or vibration.
It is effective in meeting today's demands.

[Brief explanation of drawings]

FIG. 1 is a side view of the excavator, FIG. 2 is a partially cutaway front view of the earth auger, and FIGS. 3A to 3C are cross-sectional plan views showing the construction state. A...excavator, 4,4'...earth auger, 5...screw, 7...lid, 8,8'...notch, hole a, b...
Recess, c, c'...concrete pillar.

Claims (1)

[Claims] 1 A screw provided on the outer peripheral surface of a hollow earth auger is partially cut out at a position along its center line, and the cutout is formed into an arc shape with a radius of curvature approximately equal to the radius of curvature of the screw. Then, use the earth auger described above to excavate to a predetermined depth in the ground, align the notch with the advancing direction of the earth retaining wall construction, and then stop. Next, use the same earth auger as above to the notch of the previous earth auger. The earth auger of the following order is also stopped with its notch aligned with the direction of movement of the earth retaining wall construction, and then the earth auger of the previous order is pulled out and ready-mixed concrete is poured into the hole created by the pulling out. By injecting concrete through the earth auger, a concrete column having an arcuate concave portion in the length direction is formed, and thereafter, the process of excavating with the earth auger, pulling out the earth auger of the priority order, and filling with ready-mixed concrete is repeated in the same manner. A cast-in-place concrete earth retaining method characterized by forming earth retaining walls that overlap each other in the recessed part of a concrete column.