JPH0458558B2 - - Google Patents

Description

[Detailed Description of the Invention] <<Industrial Application Field>> This invention provides a tunnel using a shield excavator,
This article relates to excavation methods for tunnels, etc., and in particular to curved excavation methods using shield excavators.

<Prior Art and Problems> As is well known, when excavating a subway tunnel, etc., it is necessary to excavate not only in a straight line but also in a curved line.

Shield excavators are widely used as excavation equipment for tunnels and the like. The main body of a normal excavator is integrally formed into a cylindrical shape, and for construction with relatively gentle curves, an integrated excavator is used to excavate.
Particularly when excavating in a sharp curve, a split-type shield excavator is used, in which the excavator main body is divided into front and rear parts, and these parts are connected in a bendable manner.

In this type of shield tunneling machine, for example, in addition to the jack for shield propulsion, a jack for changing direction, called a bending jack, is installed in the divided part, and this jack can be expanded and contracted when changing direction. The front part of the divided main body is pushed to one side, allowing for curved construction.

FIG. 1 shows an excavation method using a split shield excavator when excavating a meandering, sharply curved section (,) sandwiched between straight sections (,).

In the straight section (,), the front part 1 of the excavator body
and the rear part 2 are excavated in a nearly parallel state, and in the section that curves to the left in the excavation direction, the left rear end of the front part 1 is excavated with the left front end of the rear part 2 close to the left front end of the rear part 2. Conversely, in a section curved to the right, excavation is performed with the right rear end of the front section 1 being close to the right front end of the rear section 2.

By the way, when constructing a curved line in such a state, a part of the front part 1 that is turned to the left or right will protrude outward from the curved line to be excavated, and the part protruding from the curved line will not be excavated. However, an extra excavation must be made in the area shown in FIG. 1A so that the rear section 2 that will pass later can pass through.

If the curve is bent at a steep angle, the amount of excess excavation will increase depending on the angle. However, in the past, this was left as is, resulting in the following problems. That is, the rear part 2 passing after the front part 1 is
Due to the accumulation of over-excavation soil, there is a tendency to deviate to the outside of the curve and pass through, making it difficult to pass smoothly, and the passing resistance of the rear section 2 increases, making it difficult for the front section 1 to proceed as planned. Sometimes errors occurred in the direction.

Furthermore, since the front part 1 and the rear part 2 tend to deviate in different directions, there was a risk that excessive twisting would be applied to the divided parts of the excavator.

Similar problems exist even when a gentle curve is excavated using an integrated excavator, although the degree of the problem differs because the amount of excess excavation is small.

《Object of the invention》 This invention was made in view of the above-mentioned conventional problems, and its purpose is to remove excess earth and sand generated when excavating in a curved shape with a shield excavator. The company provides a curved excavation method using a shield excavator.

<<Structure of the Invention>> In order to achieve the above object, the present invention provides the following features:
Pressurized fluid is ejected in the direction of excavation from more than 1/2 of the rear part of the excavator body along the excavation direction, while pushing the over-excavation earth and sand that accumulates on the outer periphery of the shield excavator to the face inside the switching direction. Characterized by excavation.

<<Example>> Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIGS. 2 to 4 show a split shield excavator used in the curved excavation method according to the present invention.

The excavator shown in the figure is of a type provided with a partition wall, and has a front portion 1 which is divided into two parts of a cylindrical main body 10.
2 and a rear part 14, and a rotary excavation cutter 18 driven by a motor 16 is installed in the front of the front part 12.
is installed.

Further, in the front part 12, a partition wall 20 is provided at a predetermined interval on the back side of the cutter 18, and a chamber chamber 22 for storing excavated earth and sand therein is defined.
In addition, a screw conveyor 24 is installed to carry out the excavated earth and sand from inside the chamber chamber 22, with its tip penetrating into the chamber chamber 22.
An opening/closing lid 26 for discharging excavated earth and sand is provided at the rear of the screw conveyor 24.

And, in the connecting part between the front part 12 and the rear part 14,
As shown in FIG. 3, a plurality of propulsion jacks 28 for pushing the excavator main body 10 forward are installed at intervals in the circumferential direction, and a bent jack 30 for changing direction is provided. There is.

Furthermore, an annular seal packing 32 is interposed at the connecting portion between the front part 12 and the rear part 14 to ensure water-tightness, and a valve 34 is provided in the rear part 14 to allow pressurized fluid to flow therethrough. As shown in FIG. 3, a plurality of pipes 36 are arranged with their open ends fixed to the wall surface 14a of the rear part 14 at substantially symmetrical positions with respect to the vertical plane of the rear part 14, and the lower half is raised. It is set up so that it is dense.

The open end of each pipe 36 is connected to the rear part 14 shown in FIG.
The nozzle hole 14b communicates with a nozzle hole 14b penetrating the wall surface 14a, and the nozzle hole 14b opens into a recess 14c recessed in the wall surface 14a.

The recess 14c is substantially fan-shaped and widens toward the front 12, and is deepest at the opening of the nozzle hole 14b, and is inclined to become shallower toward the front 12. It is sloped along this slope.

Therefore, the pressurized fluid flowing into the nozzle hole 14b via the pipe 36 is transferred to the recess 1 as shown in FIG. 4b.
It ejects toward the front part 12 side along the slope of 4c,
Excavated soil that accumulates around the outer circumference of the excavator on the inside of the turning direction is pushed toward the face.

Next, a method of excavating using the excavator having the above configuration will be explained.

Here, when excavating earth and sand by rotating the cutter 18 of the excavator, propulsion by the propulsion jack 28, and when excavating in a curved shape, the front part 12 and the rear part 14 are used.
The operation is performed in almost the same manner as the conventional method described above.

That is, to explain using FIG. 1, in the straight section (,), the front part 12 and the rear part 14 are in a parallel state, and in the curved part (,), the rear end of the front part 12 and the rear part are in a parallel state when changing direction. 14 and excavate with the front ends close together.

What should be noted here is that in the excavation method according to the present invention, when excavating the curved section (,), the valve 34 of the pipe 36 is opened and the pressurized fluid is supplied to the rear part through the nozzle hole 14b. 14 toward the front section 12, and pushes the over-excavation soil A generated on the sides as the front section 12 moves toward the tip side of the front section 12, that is, toward the face side.

The over-excavated earth and sand pushed away in this way is taken into the chamber chamber 22 together with the earth and sand excavated by the excavation cutter 18, and is discharged to the outside by the screw conveyor 24. Here, the pressurized fluid is
For example, high pressure air is preferred.

In addition to high-pressure air, it may also be high-pressure jet water, muddy water, air bubbles, etc.

When compressed air or muddy water is used, a valve 38 is provided on the partition wall 20 in order to discharge these fluids that have flowed into the chamber chamber 22.

This valve 38 is especially necessary in the case of an excavator equipped with a partition wall 20, and by opening this valve 38, pressurized fluid is ejected to the front portion 12 side through the nozzle hole 14b. This is to form a path for excess excavation earth and sand pushed toward the face side to be discharged to the outside by the screw conveyor 24 via the chamber chamber 22, and is not necessary in a type of shield excavator without the partition wall 20.

By the way, during the above-mentioned curved excavation, the front part 1
Since the over-digging caused by the propulsion in step 2 occurs only on the inside of the direction of direction change, the pressurized fluid may be ejected only in this direction.

Further, in this case, pressurized fluid with a reduced pressure may be ejected to the other side.

Now, in the method of the present invention that performs curved construction with the above-mentioned configuration, when excavating in a curved shape, the side surface of the front part 12 is excavated while jetting pressurized fluid from the rear part 14 toward the front part 12. This makes it possible to sweep away excess earth and sand generated during excavation, allowing the rear part 14 to move smoothly, passing resistance is significantly reduced, and excessive twisting is not applied to the divided parts.

Additionally, errors in curved construction due to passing resistance are reduced, allowing for accurate excavation along preset curves. Furthermore, these effects make it easier to construct sharp curves that require changing direction at large bending angles.

In addition, although the above-mentioned example illustrated the case where curved construction is carried out using a split-type shield excavator having a partition wall 20, the implementation of the present invention is not limited to this, and a shield excavator without a partition wall 20 may be used. Alternatively, an undivided, integrated shield excavator may be used, and in either case, substantially the same effect as the above embodiment can be obtained.

Further, the pressurized fluid may be ejected from both the front part 12 and the rear part 14. In other words, if the over-excavated earth and sand can be removed by the pressurized fluid ejected from the inside of the shield excavation machine in the excavation direction, the ejection location can be Not a problem.

<<Effects of the Invention>> As explained in detail in the examples above, in curve construction using the shield excavator according to the present invention, over-excavation earth and sand that were an obstacle to construction when constructing gentle and sharp curves can be removed. By pushing it toward the face, it can be removed and construction becomes easier.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of curved excavation construction, Fig. 2 is an overall view of the shield excavation machine used in the present invention, Fig. 3 is a longitudinal sectional view of the main part of Fig. 2, and Fig. 4 a is a plane of the nozzle hole. 4B is a sectional view of FIG. 4A. 10... Main body, 12... Front part, 14... Rear part,
16...Motor, 18...Drilling cutter, 20...
...Partition wall, 22...Chamber room, 24...Screw conveyor, 26...Opening/closing lid, 28...Propulsion jack, 30...Folding jack, 32...Seal packing, 34...Valve, 36...Piping .

Claims (1)

[Scope of Claims] 1. When changing the direction of the shield excavator to excavate in a curved shape, pressurized fluid is spouted in the excavation direction from more than 1/2 of the rear of the excavator body along the excavation direction;
A curved excavation method using a shield excavator, characterized in that excavation is carried out while pushing excess excavation soil that accumulates on the outer periphery of the shield excavator to a face inside the turning direction. 2. The shield tunneling machine described in claim 1 is characterized in that the tunneling machine main body is divided into front and rear parts, and these front and rear parts are connected in a bendable manner. Curved excavation method. 3. The above-mentioned shield excavator is equipped with a partition wall, and the partition wall is provided with a valve for discharging pressurized fluid, and after the excess excavation soil is taken into the chamber separated by the partition wall, the valve is opened, and the pressurized fluid is discharged. A curved excavation method using a shield excavator according to claim 1 or 2, characterized in that the shield excavator is discharged from the chamber. 4 The pressurized fluid is muddy water or high pressure jet water,
A curved excavation method using a shield excavator according to claim 1, 2, or 3, characterized in that the shield excavator is made of high-pressure air or bubbles.