JPH0396516A - Variable width excavator and width widening excavation method - Google Patents

Abstract

PURPOSE:To increase the thickness of an underground wall at a place having large external force of the ground and to make it possible to construct an advantageous underground structure constructionally by providing side cutters to drum cutters of a horizontal multi-shaft excavator, and advancing and retracting in the drum shaft direction to carry out a partial width widening excavation. CONSTITUTION:Side cutter 3 are mounted to both sides of a pair of drum cutters 2A and 2B, an expansion pressure cylinder 7 having a tension spring 8 to the inside thereof is liquid-tightly loaded between the cutter 3 and the ends of the drum cutters 2, and it is connected together with a hydraulic port 6 provided to he inside of a rotary shaft 5. When oil pressure is applied from the hydraulic port 6, the expansion pressure cylinder 7 expands against the spring 8, and the drum cutters 3 are pushed outward. In addition, the side cutters 3 are excavated vertically to a specific depth H1 with an excavation width C1 by a variable width excavator while supplying stabilized liquid 15, and the oil pressure is applied from the hydraulic port 6 at a place necessary for a widening width. Then, the side cutters 3 of the ends of both sides of the drum cutters 2 are pushed outward for an excavated width C2 only through the expansion pressure cylinder 7 to carry out the width widening excavation.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides a variable width excavator for excavating an underground trench, for example, when constructing a continuous underground wall, and a variable width excavator for widening a required part of an underground trench. Regarding widening excavation method. [Prior art] Generally, when constructing a continuous underground wall, an underground trench is first excavated, but if the wall thickness and depth of the underground wall to be constructed are large, a large number of bits are planted on the surface. A horizontal multi-spindle excavator with a rotary drum cutter is used. Fifth
The figure is a schematic diagram of such a conventional excavator 1, and FIG. 6 shows a cross section taken along line FF in FIG. 5. In the figure, 2A, 2
m is a drum cutter, and these two sets of drum cutters are 2m long.
When the two screws are rotated as a pair by being driven by a gear device 9, the ground is excavated by a large number of bits 4 provided on the surface. Also, the cross section of the underground trench excavated at this time is D. If ≠C, then it is a rectangle, and if DI=C+, it is a square.

[Problems to be Solved by the Invention] However, when an underground trench is excavated using the conventional underwater multi-axis excavator as described above, the cross section of the trench becomes a rectangle with the same dimensions from top to bottom.

Therefore, the wall thickness of the continuous underground wall constructed using this method is the same at any location. Therefore, if there is a place at a certain depth underground where the external ground force is large, it would be convenient to increase the wall thickness of the underground wall at that part, but with the conventional excavation method using an excavator, the required Since it is impossible to excavate only a portion to widen it, it is not possible to construct an underground wall with a partially increased wall thickness at a certain depth, which causes the problem that the wall is designed with a wall thickness that is subject to a large external force from the ground.

This invention has been made in view of such conventional problems, and it solves the above problems by providing a side cutter to the drum cutter of a horizontal multi-axis excavator and performing partial widening excavation using this excavator. is aimed at solving.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention provides a horizontal multi-layer structure equipped with a drum cutter for excavating an underground trench to a required depth when constructing a continuous underground wall or the like. The shaft excavator is a variable width excavator in which side cutters that can move forward and backward in the axial direction of the drum cutter are provided at both ends of the drum cutter, and when excavating underground trenches, By using a variable width excavator having side cutters provided at both ends of a drum cutter of a horizontal multi-axis excavator, and expanding the distance between the two side cutters at the required depth of the underground trench, The present invention provides a widening excavation method characterized by widening a predetermined portion of the underground trench.

[Effect]

Since the present invention has the above-described structure, the side cutters provided at both ends of the conventional drum cutter can move forward and backward in the axial direction of the drum cutter, so the excavation width can be changed from the conventional fixed width to the side cutter. It can be made into a variable width excavator that has an excavation width that is equal to the advance and retreat distance. Also,
For example, underground trenches are excavated when constructing a continuous underground wall, but if it is necessary to increase the wall thickness of the underground wall at a certain depth, the part of the underground trench that corresponds to the large wall thickness will be excavated. If it can be widened, that goal will be achieved. However, by excavating using the variable width excavator, and expanding the distance between the side cutters of the variable width excavator when the depth of the underground trench is reached, the required part of the underground trench is widened. This means that the above objectives can be met.

〔Example〕

The present invention will be explained below based on the drawings. 1 to 4 are diagrams showing an embodiment according to the present invention.

1 is a diagram corresponding to the view in the direction of arrow A in FIG. 5, which is a conventional example, FIG. 2 is an enlarged view of the EI-E1 cross section in FIG. 1, and FIG. E! It is an enlarged view of a cross section.

In the drum cutter 2, the drums 2 and 2 are symmetrically fixed to the rotating shaft 5 to form a set, and further, the drum cutter 2 is formed as a pair with another similarly shaped drum cutter 1 & Il. As shown in the conventional example shown in FIG. 5, they are attached to respective rotating shafts 5A and 5m arranged in parallel, and are configured to rotate in the direction of the arrow. Furthermore, side cutters 3 (3., 3g) are attached to both side ends of each of the drum cutters 2A and 2, forming the pair, as shown in FIGS. 2 and 4. That is, the side cutter 3 is fixed to a movable cylinder 12 that is slidably fitted into the drum side cylinder 11, and the flange portion 12a of the movable cylinder 12 is hooked to the inward flange 11a of the drum side cylinder l1. This prevents it from separating from the drum 2.

Moreover, between the end face of the drum cutter 2 and the side cutter 3, a telescopic pressure cylinder 7 with a tension spring 8 installed therein is interposed in a liquid-tight manner.
It communicates with a hydraulic boat 6 provided within the rotating shaft 5.

Therefore, when no hydraulic pressure is applied to the telescopic pressure cylinder 7, the side cutter 3 is pulled by the tension spring 8 and comes into contact with the end of the drum cutter 2, as shown in FIG. When hydraulic pressure is applied from the boat 6, the telescopic pressure cylinder 7 expands against the elasticity of the tension spring and pushes the side cutter 3 outward. At this time, side cutters 3. The distance between and 3t increases, and this distance C+ (see FIG. 1) in the state of FIG. 2 widens to the distance Mct in the state of FIG. A plurality of connecting rods 13 are provided for connecting the side force cutter 3 to the drum cutter 2 and rotating them integrally (only one portion is shown in FIG. 4).

Additionally, a wing force vine (not shown) or the like is provided between the drums 2A and 2++ to prevent any remaining excavation from occurring, and the rotation of the drum cutter 2 is driven by an underwater motor (not shown). 14 is a part containing a submersible pump, etc., which discharges the excavated mud through a reverse pipe 16 to a device that separates the stabilizing liquid 15 from earth and sand.

Next, when excavating an underground trench while supplying the stabilizing liquid 15 with the variable width excavator configured as described above, initially the side cutter 3 is set as shown in Fig. 2, and the excavation width is adjusted as before. When excavating vertically with CI to a predetermined depth H1, for example, there is a layer below the H1 plane where the external ground force is large, and therefore it is necessary to increase the wall thickness of the underground wall between the depth h, If it is desired to widen the excavation width from depth H to H2 to C2, by applying hydraulic pressure from the hydraulic boat 6 provided at the center of the drum cutter rotating wheel 5,
Resisting the elasticity of the tension spring 8, the side cutters 3 at both ends of the drum cutter 3 are pushed outward via the telescopic pressure cylinder 7 to the state shown in FIG. 4, and the depth h shown in FIG. Excavate and widen the gap.

When this widening is completed, the hydraulic pressure is removed, and the side cutter 3 is pulled by the tension spring 8, resulting in the state shown in FIG. 2. Therefore, we finish excavating this underground trench and move on to the next underground trench excavation work. If a plurality of underground trenches excavated by repeating such operations are connected to each other and an underground trench with a rectangular cross section is excavated, widening excavation with a continuous width C2 between the depth H+ and H2 can be performed.

The bits 4 made of cemented carbide or the like implanted in the drum cutter 2 or the side force cutter 3 are arranged so that their excavation trajectories do not overlap with each other.

〔Effect of the invention〕

As explained above, according to the present invention, since the side cutter attached to the drum cutter is moved back and forth in the direction of the axis of the drum, the side cutter is moved in the direction of the depth of the ground. Of meaning. Since widening excavation can be performed at certain locations, the wall thickness of underground walls can be increased in locations where external ground forces are large, making it possible to construct underground structures that are structurally advantageous.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram showing the outline of a variable width excavator and an excavation method according to the present invention, Fig. 2 is an enlarged cross-sectional view of E and E + in Fig. 1, and Fig. 3 is a view taken from arrow B in Fig. 2. 4 is an enlarged cross-sectional view of Ez Ex in FIG. It is an F sectional view. 2 (2.,2■,2.,2m)...Drum cutter, 3 (3,,3■)...Side cutter. Figure 1

Claims (2)

[Claims] (1) In a horizontal multi-shaft excavator equipped with a drum cutter for excavating an underground trench to a required depth when constructing a continuous underground wall, etc., the axis of the drum cutter is marked at both ends of the drum cutter. A variable width excavator characterized by being equipped with a side cutter that can move forward and backward in different directions. (2) When excavating an underground trench, a variable-width excavator, which is a horizontal multi-axis excavator with side cutters provided at both ends of a drum cutter, is used, and the distance between the two side cutters at the required depth of the underground trench is used. A widening excavation method characterized by widening a required part of the underground trench by excavating an enlarged distance.