JPH0754334A - Subterranean excavator - Google Patents

Abstract

PURPOSE:To accomplish landslide protection work efficiently and within a short time even if the ground might include subterranean obstructions by excavating the ground with a lower cutter drum and stirring up and mixing the excavated earth together with a half hardening stabilizer. CONSTITUTION:A cutter drum 8 and a stir-up drum 9 are rotated as a kelly-bar 3 is lowered into the ground. The ground is dug with the cutter drum 8 positioned below. The dug earth is stirred up with the stir-up drum positioned above. A grout hose 6 is unwound from a reel as the kelly-bar 3 is lowered. The force fed grout is spouted from the exhaust nozzle 7a of a frame 7 through the hole 6 and mixed with the stirred up earth. Simultaneously, wooden piles and other subterranean obstructions are also broken into pieces. Thus an underground earth wall can be completed within a short period of time in the ground foundation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an underground excavator suitable for use in a soil mixing wall method, for example.

[0002]

2. Description of the Related Art Soil mixing walls with middle rows are often adopted as simple mountain retaining works used for construction work on the first and second basements. . This method is for constructing a wall body for one element by discharging a self-hardening stabilizing liquid such as cement milk from the tip of the drilling of the earth and sand on site with a multi-axis kneading auger and mixing with the earth and sand.

By the way, since this method uses a multi-axis kneading auger, it is suitable for soft ground, but it can be used for hard ground and ground with obstacles such as cobblestone and wooden piles. Can not.

As an alternative construction method for such a ground,
After continuously excavating a groove of a certain width using a self-hardening stabilizing liquid, H-shaped steel is built in the groove at a predetermined pitch, and this is integrated with a solidified body of the self-hardening stabilizing liquid. Has been done.

[0005]

However, in such a construction method, although a more robust structure can be obtained, the construction period becomes 20 to 30% longer, and materials such as H-section steel are required. Therefore, the construction cost was increased by 20 to 30%, which was not suitable as a construction method for simple mountain stay construction.

The present invention solves the above problems, and the object thereof is to efficiently carry out mountain demolition work even on hard ground, or ground with obstructions such as cobblestone and wooden piles. The underground excavator is provided.

[0007]

In order to achieve the above object, the present invention provides a frame arranged at the tip of a kelly bar, and a pair of cutter drums for excavation which are rotatably supported on the lower part of the frame. A pair of mixing drums above the cutter drum and rotatably supported by the frame, a motor provided on the frame for driving the cutter drum and the stirring drum to rotate, and a motor provided on the frame. And a spout for ejecting grout.

[0008]

With the above construction, by rotating the drums while lowering the kelly bar into the ground, the cutter drum located below digs the ground, and the excavated soil is agitated by the agitating drum located above. And mixed with grout spouted from the spout.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows the overall construction of an underground excavator according to the present invention. A kerry bar 3 is held vertically and vertically movable on a crane 2 of a base machine 1 installed on the surface of the ground. The excavator body 4 is arranged at the tip of the kelly bar 3, and the grout pump 5 is installed on the ground surface. The grout pump 5 is connected to the excavator body 4 through the grout hose 6 wound on the hose reel 6a. ing.

As shown in FIGS. 2A and 2B, the excavator main body 4 has a frame 7 fixed to the tip of the kelly bar 3.
And on the lower side of the frame 7, a total of 4
The pair of cutter drums 8 are rotatably supported at respective positions, the pair of stirring drums 9 are rotatably supported at a total of four positions above and below the frame 7, and are supported by the frame 7. It is provided with rotation driving motors 10 and 11 connected to the drums 8 and 9.

Further, the frame 7 has the drums 8 and 9 described above.
Spout 7 connected to the tip of the hose 6 in the vicinity of the
a is provided.

The cutter drum 8 is a cutter for ground cutting equivalent to that used in a hydro phrase excavator, and has a large number of excavating bits 8a on the outer circumference of the drum. The agitating drum 9 is for ground agitation, and is provided with a plurality of agitating blades 9a on the outer circumference of the drum. As shown in FIG. 2A, the total length of the drums 8 and 9 before and after the frame 7 is sandwiched. Is the width of the excavation groove, and the total width of the left and right drums 8 and 9 is the length of the wall for one element, as shown in FIG.

The motors 10 and 11 are hydraulic or liquid-tight electric motors, and the motors 10 and 11 are connected to the base machine 1 side through hydraulic hoses or cables (not shown) arranged in parallel with the kelly bar 3.

In the above structure, by rotating the drums 8 and 9 while lowering the kelly bar 3 into the ground E,
The cutter drum 8 located below digs the ground E, and the excavated soil is agitated by the agitating drum 9 located above. As the kelly bar 3 descends, the grout hose 6 is fed from the reel 6a, and the grout pumped by the grout pump 5 is jetted from the jet port 7a of the frame 7 through the hose 6 and mixed with the stirred sand. In addition, the cement-based solidifying material can be injected in parallel with the grout injection.

At the time of this excavation, the ground E is hard ground, boulders,
Even in the case of the ground having underground obstacles such as pine piles, the excavation torque of the cutter drum 8 is large, so that the excavation can be performed with high efficiency, and the underground obstacles are crushed. It mixes with grouting, cement-based solidifying material, etc. together with excavated soil.

After excavation and mixing and stirring work to the required depth, when the drums 8 and 9 are rotated while pulling up the kelly bar 3, both the drums 8 and 9 mix the earth and sand and grout again, so that the cement system solidifies. The effect of mixing with the material is increased, and the adhesion of earth and sand to the cutting bit 8a and the stirring blade 9a is prevented, and the soil retaining wall E1 for one element is completed in the ground E as shown in FIG.

After that, by repeating the same work so as to be continuous with this underground soil retaining wall E1, a continuous integral underground wall can be constructed.

If the jet port 7a is directed toward the cutting bit 8a of the cutter drum 8 and the stirring blade 9a of the stirring drum 9,
The grout ejected from here can prevent excavated soil from adhering to the bit 8a, the stirring blade 9a, and the like.

Further, in this embodiment, the stirring drum 9 has a shape different from that of the cutter drum 8, but the stirring drum 9 may have the same shape.

After the excavator main body 4 is pulled up, H-section steel may be built as a reinforcement work, or it can be used as an underground soil retaining wall as it is, which is appropriately selected according to the required strength and economical efficiency. can do.

[0022]

As described above in detail with reference to the embodiments, in the underground excavator according to the present invention, the lower cutter drum is rotated by rotating the drums while lowering the kelly bar into the ground. The ground is excavated, and the excavated soil is agitated by the agitating drum above and mixed with the self-hardening stabilizing liquid ejected from the ejection port through the grout pump.
It is suitable for excavating and mixing and agitating with high efficiency even on hard ground or ground with obstacles such as cobblestone and wooden piles, and is suitable for shortening the construction period and reducing the construction cost.

[Brief description of drawings]

FIG. 1 is an overall view of an underground excavator according to the present invention.

FIG. 2A is a side cross-section of the excavator main body. (B) is the same front view.

[Explanation of symbols]

 1 Base Machine 3 Crane 4 Excavator Main Body 5 Grout Pump 6 Grout Hose 7 Frame 7a Jet Port 8 Cutter Drum 8a Excavation Bit 9 Stirring Drum 9a Stirring Blade 10,11 Driving Motor

Claims (1)

[Claims] 1. A frame disposed at the tip of a kelly bar, a pair of excavating cutter drums rotatably supported on the lower portion of the frame, and a rotatably movable frame above the cutter drum. A pair of shaft-supported stirring drums for mixing, a motor provided in the frame for rotationally driving the cutter drum and the stirring drum, and an ejection port provided in the frame for ejecting grout. Underground excavator to do.