JPH06100069B2 - Excavation method for enlarged holes - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a method of excavating an enlarged hole for excavating a large-diameter hole in the ground such as a hard rock, cobblestone layer, and sand gravel layer.

<Prior Art> A small-diameter pilot pipe is previously propelled from the starting shaft to the reaching shaft, and then a large-diameter hole drilling device is attached to the tip of the pilot pipe to pilot from the reaching shaft to the starting shaft. There is a method of burying a propulsion pipe while excavating a hole having a diameter larger than that of the pipe.

The hole-expanding digging device used in the construction method is composed of a funnel-shaped hollow cylinder, and a large number of chips for digging, which are digging means, project on the surface in the digging direction. The structure is such that a hole with a larger diameter than the pipe can be excavated.

<Problems to be Solved by the Present Invention> The above-described drilling technique for expanding holes has the following problems.

(A) If the excavated ground is hard rock such as boulders or boulders,
Excavation work becomes very difficult because the tip wears easily and is easily damaged.

Therefore, the excavation efficiency tends to decrease and the construction period tends to be prolonged.

In addition, when it is judged that excavation of bedrock is impossible, the planned line must be changed, which requires a lot of time and cost.

(B) It has been proposed that a roller bit or roller cutter is attached to the front surface of the hole-expanding digging device. It is necessary to deploy the own propulsion device.

In addition, there is a problem that the excavation speed is slow because the excavation efficiency is low.

<Object of the present invention> The present invention has been made in view of the above problems, and an object of the present invention is to provide a method for excavating an enlarged hole, which can excavate the enlarged hole efficiently and surely even on hard rock.

<Structure of the Present Invention> An embodiment of the present invention will be described below with reference to the drawings. First, a hole expanding drilling device used for drilling an expanded hole will be described.

<A> Configuration of the hole expanding digging device An example of the hole expanding digging device 1 is shown in FIGS.

The hole-expanding excavator 1 includes a bottomed main body 2, an excavating means and an earth removing means provided in the main body 2.

The bottom surface 21 of the main body 2 is completely closed and formed, and the front surface 22 opposite to the other bottom surface is provided with an inlet 23 for taking in excavated earth and sand.
Open and form.

Then, the front surface 22 of the main body 2 is fixed to the tip of the pilot pipe 3 in the direction of excavation of the hole.

Therefore, as the pilot pipe 3 rotates, the hole drilling device 1 rotates together.

<B> Excavation Means Although the conventional excavation means of the hole-drilling device uses propulsion, the hole-drilling device 1 employs the drilling device 4 that can excavate almost no propulsion.

This drilling device 4 uses, for example, compressed air for the drill head 41.
A well-known down-the-hole drill that excavates by operating a piston can be adopted.

That is, in the main body 2, one or a plurality of holes are arranged in parallel with the axis of the hole-drilling device 1.

At this time, the drill device 4 exposes the drill head 41 to the front surface 22 avoiding the inlet 23 and stores it.

The installation position and the installation number of the drill device 4 differ depending on the drilling meter of the hole expansion, but the installation position and the installation number are determined so that the locus of the drill head 41 can pass at least the entire range of the front surface 22.

Further, in order to supply compressed air to the drill device 4, the hollow shaft 51 of the screw auger 5 inserted into the pilot pipe 3 is used.
Is used as a compressed air supply path, an air swivel 52 is attached to the tip of the screw auger 5, and compressed air can be continuously supplied when the screw auger 5 rotates.

<C> Earth Exhaust Means The earth and sand excavated by the drill device 4 is fed from the intake 23 to the main body 2
It is taken in and then transferred to the base end side of the pilot pipe 3 by the screw auger 5 which rotates in the main body 2 and discharged.

Next, a method of excavating the enlarged hole will be described.

(1) Excavation of the guide hole (Fig. 3) First, the guide hole is excavated according to the planned line.

To excavate the leading hole, for example, the rotary propulsion device 6 is installed on the side of the starting shaft A, and the multi-drill 7 and the leading conduit 8 are set to perform the excavation.

In the excavation work of the leading hole, even if there are boulders on the excavated ground, the boulders can be easily penetrated by the multi-drill 7, so that the excavation along the planned line can be performed.

The excavation work is advanced while sequentially connecting the pilot pipes 3 having the screw augers 5 built therein, and the excavation shaft B is excavated.

(2) Installation of hole-expanding drilling device After opening the guide hole penetrating up to the reaching shaft B, the pilot conduit 8 is removed from the tip of the pilot pipe 3 and the hole-expanding drilling device 1
Replace.

(3) Excavation of the enlarged hole (Fig. 4) On the side of the starting shaft A, supply of compressed air is started from the base end of the screw auger 5, and at the same time, the rotary propulsion device 6 is operated,
While giving rotation to the pilot pipe 3, it is pulled back to the starting shaft A side.

As a result, as shown in FIG. 1, the drilling device 4 incorporated in the hole expanding drilling device 1 hits the ground to carry out drilling.

The drill head 41 revolves in response to the rotation of the pilot pipe 3, and sequentially drills the unexcavated portion around the pilot pipe 3.

The excavated earth and sand is transferred by the screw auger 5 in the pilot pipe 3 and discharged to the starting shaft A side.

Even if rocks such as boulders are present on the way, these rocks are crushed with high efficiency by the impact of the drill head 41 and the enlarged hole is excavated.

As a result, an enlarged hole having an enlarged hole diameter is excavated around the leading hole.

Since the excavation by the expansion excavation device 1 is performed by the drill device 4, it does not require a large propulsive force as in the past.

In parallel with the excavation work of the hole expanding excavator 1, the laid main pipe such as the fume pipe 9 is propelled from the reaching shaft B to the starting shaft A.

While repeatedly collecting the pilot pipe 3, the enlarged hole is excavated until the starting shaft A is reached.

<Other Examples> When the drilling diameter of the enlarged hole is large, as shown in FIG. 5, the drilling device 4 having a different distance from the axial center of the hole-drilling device 1 is used.
Place multiple drills and drill.

<Effects of the Present Invention> Since the present invention is as described above, the following effects can be obtained.

(A) Even if the rock is hard, it can be crushed with a drill device without fail, so that it is possible to excavate an enlarged hole.

(B) By selecting the number of drilling devices and the number of installation positions, it is possible to efficiently drill even the largest holes.

(C) The conventional hole-expanding drilling device requires a large propulsion force because it is an excavation system that uses propulsion force.

According to the present invention, since it is possible to excavate the enlarged hole by hitting the drill device, it is not necessary to give a particularly large propulsive force to the hole-drilling device.

Therefore, it is possible to use a rotary propulsion machine having a smaller propulsion capacity than the conventional one.

(D) An inlet for earth and sand is provided in front of a bottomed cylinder, and excavated earth and sand can be taken into the cylinder through this inlet and discharged to the starting shaft side through a pilot pipe.

Therefore, the earth removal can be completed at the same time as the burying of the fume pipe is completed, and the construction period and the cost can be significantly reduced.

[Brief description of drawings]

 Fig. 1: Explanatory view of the vertical cross section of the hole drilling equipment Fig. 2: Cross sectional view of II-II in Fig. 1 Fig. 3: Explanatory drawing of pilot pipe propulsion Fig. 4: Excavation of large diameter hole Explanatory drawing of FIG. 5: Explanatory drawing of other embodiments

 ─────────────────────────────────────────────────── --- Continuation of the front page (56) Reference JP 62-153492 (JP, A) JP 52-15114 (JP, A) JP 57-169197 (JP, A) JP 57- 169198 (JP, A)

Claims (1)

[Claims] 1. A pilot pipe having excavation means and soil removal means at its tip is connected and propelled from the starting shaft to the reaching shaft, and the diameter of the pilot pipe exposed at the reaching shaft is larger than that of the pilot pipe. In the bottomed cylinder of the above, a front side of the bottomed cylinder, which faces the bottom surface, is provided with an intake for taking in the excavated earth and sand, and inside the bottomed cylinder, a drilling device for striking toward a starting shaft. The hole-expanding drilling rig is connected to the unit, and the hole-expanding drilling rig is rotated through the pilot pipe. A method for excavating an enlarged hole, which comprises excavating an unexcavated portion, taking in excavated earth and sand from the intake, and discharging the soil through the pilot pipe.