JPH0531610B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for driving piles into a rubble layer, in which a hole is dug in the rubble layer, the hole is filled with sand, and then a pile is driven.

[Prior art]

The chestnut stones that form the rubble foundation on the underwater ground are
Since the size is from 20cm to 100cm in diameter,
In order to penetrate the pile into the rubble foundation, one idea is to first use a rock auger to drill a hole in the rubble foundation with a diameter larger than the diameter of the pile, and then drive the pile into that hole. It will be done.

However, in this case, when the auger screw of the rock auger excavator is pulled out while being reversed, the auger head at the tip of the auger screw breaks the stone pressed against the hole wall during excavation and collapses into the hole. There is a problem in that the hole that has been removed becomes clogged, making it impossible to drive the next pile.

As a countermeasure to this problem, the holes excavated as described above are filled with sand to prevent the walls from collapsing, and the rubble layer of JP-A-59-130918 is used to make it easier to drive piles. An invention related to a pile driving method is known.

Other conventional methods using donut augers are also known.

The method using the donut auger excavator will be explained with reference to a series of drawings from FIG. 6 to FIG. 10. First, in FIG. While rotating the auger screw 2 penetrated inside the auger screw 2 in the direction of arrow B, that is, in the opposite direction to arrow A, with an inner tunneling machine (not shown), Then, excavation is made into the rubble layer 4 formed on the underwater ground 3.

In this case, with Augus Creu 2 in advance,
The hollow casing 1 is made to follow, and the hole 5 is excavated to a predetermined depth shown in FIG. 7 while pushing the rubble outward during excavation to complete the drilling.

Next, as shown in Figure 8, the Augus Screw 2
After pulling out the chisel while rotating, the hollow casing 1 left in the excavated hole 5 is filled with sand 7 using a belt conveyor 6 or the like, as shown in FIG.

Thereafter, as shown in FIG. 10, the hollow casing 1 is pulled out from the hole 5, and the sand 7 filled in the hole 5 is removed.
Piles can be easily driven by driving piles (not shown) into the pillars.

However, in the above conventional method of driving piles into the rubble layer 4, sand 7 is filled using a belt conveyor 6 etc. after the auger screw 2 is pulled out, so when driving piles in a place close to a quay, However, the belt conveyor 6 may not be able to be used at a location far from the quay, and the work efficiency is also poor.

In addition, in the case of diagonal piles, the auger screw 2 cannot be removed from the hollow casing 1, so there is a drawback that the efficiency of sand injection is extremely low.

[Purpose of the invention]

Therefore, in order to solve the above-mentioned conventional problems, the present invention utilizes the hollow shaft of the auger screw when filling sand into the hole excavated by the auger screw of the donut auger excavator. By introducing sand into the hole to form a sand column, it is possible to efficiently hold the ripble layer in the hole without using a conveyor for sand supply, and also to prevent the ripple layer from being removed underwater away from the quay. The purpose is to enable drilling and retention.

[Structure of the invention]

The present invention involves inserting an auger screw into a hollow casing, excavating a rubble layer while rotating the hollow casing and auger screw in opposite directions, and then pulling out only the auger screw when excavation is completed. Slurry sand is dropped from the upper end of the hollow shaft toward the lower end, and the slurry sand is discharged into the excavated hole, filling the hollow casing in the hole with sand, and then pulling out the hollow casing. It consists of a drilling retention method for the rubble layer.

[Example] An example of piling work using the drilling holding method of the present invention will be described below with reference to the drawings. FIG. FIG.

This donut tsuuger excavator is for excavating a hole 5 in the rubble layer 4 on the water bottom ground 3 below the water surface W, as in the conventional example, and is operated by the outer excavator 9 mounted on the turret 8. Steel hollow casing 1
At the same time, rotate the inner tunneling machine 1 in the direction of arrow A.
0, the auger screw 2 is rotated in the direction of arrow B to perform excavation.

Next, a sand feeding pipe 12 is connected to the upper end of the hollow shaft 2A formed in the hollow of the auger screw 2 via a swivel joint 11.

On the other hand, a stirring tank 14 is provided on the sand supply ship 13,
While the sand 7 is supplied into the stirring tank 14 by the conveyor 18, water is supplied by the submersible pump 15, and by stirring, the sand 7 is made into a slurry by the sand pump 16 through the auger cleaner via the sand pipe 12. It is possible to discharge from the lower end of the hollow shaft 2A of the u2.

Next, a second work is carried out to hold the hole in the rubble layer 4 using the donut auger excavator with the above configuration.
To explain from the figure to figure 5, figure 2 is the 6th figure.
Figure 3 shows a state in which drilling is being performed by rotating the auger screw 2 and hollow casing 1, similar to the conventional example in the figure, and Figure 3 shows a state in which drilling is completed, similar to the conventional example in Figure 7. It shows.

Therefore, as shown in FIG. 4, when only the auger screw 2 is pulled out, slurry-like sand 7 is discharged from the lower end of the hollow shaft 2A of the auger screw 2 into the excavated hole 5. As shown in FIG. 5, the hollow casing 1 in the hole 5 is filled with sand 7.

At this time, the speed at which the auger screw 2 is pulled out from the hollow casing 1 can be constantly controlled by controlling the amount of sand fed.

Thereafter, as in the conventional example shown in FIG. 10, the hollow casing 1 is pulled out and piles are driven into the pillars of sand 7 left behind.

In addition, the hollow shaft 2A of the auger screw 2 in the method of driving piles into the rubble layer 4 of the present invention
The lower end of the excavator is closed during excavation, and is opened only when the excavator is pulled out, allowing slurry-like sand 7 to be discharged.

〔Effect of the invention〕

Therefore, by adopting the method of driving piles into the rubble layer of the present invention, it is possible to easily drive piles into the rubble layer at a location away from the quay, and moreover, while pulling out the auger screw,
Filling with sand in the form of a slurry reduces the work time compared to the conventional case where sand is filled after the auger screw is completely pulled out, and moreover, the filler sand is efficiently injected into the hole. There is an effect that it can be done.

The present invention can be particularly effectively applied to piling work when there are obstacles in the rubble layer or soil, but it can also be applied to various types of piling work in civil engineering work.

More specifically, the hollow shaft of the auger crew is used to drop slurry sand into the hollow casing, eliminating the time loss of filling the sand after the auger crew is completely pulled out. The work time can be shortened because sand can be filled into the hole while the auger screw is being pulled out. Unlike feeding, it does not take time for the sand to diffuse into the water in the casing and settle, and the sand can settle quickly, improving work efficiency. In other words, it can be said that the greatest effect of the present invention is that work efficiency can be effectively improved by using a hollow shaft for the auger screw and at the same time by using slurry-like sand.

[Brief explanation of drawings]

FIG. 1 is a schematic side view of a rock auger excavator for driving piles in an embodiment of pile driving work using the pile driving method of the present invention, and FIGS. 2, 3, 4, and 5 are Figure 1 is a series of schematic side views illustrating hole excavation work using a rock auger excavator, and Figures 6, 7, 8, 9, and 10 are diagrams showing conventional pile driving into a rubble layer. 1 is a series of schematic side views illustrating a hole drilling operation according to the method; FIG. 1...Hollow casing, 2...Auger screw, 2A...Hollow shaft, 4...Rubble layer, 5...
...hole, 7...sand, 12...sand pipe, 14...
Stirring layer, 16...Sand pump.

Claims (1)

[Claims] 1. Insert the auger crew into the hollow casing, excavate the rubble layer while rotating the hollow casing and auger crew in opposite directions, and when the excavation is complete, pull out only the auger crew and remove the hollow shaft of the auger crew. Slurry sand is dropped from the top end to the bottom end, the slurry sand is discharged into the excavated hole, the hollow casing inside the hole is filled with sand, and the hollow casing is pulled out. Drill retention method.