JP2004332503A - Method and apparatus for executing tapered and under-reamed continuous wall - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable the execution of an under-reamed continuous underground wall of a wall thickness with a strength required depending on a depth etc. <P>SOLUTION: An endless chain cutter-type side-cut excavator is constituted as a multiple chain type; a cutter post with a tapered and under-reamed cross section perpendicular to the direction of excavation is used; and respective chains on the cutter post are made to go around in different orbits by an intermediate sprocket and/or a chain guide. Excavating blades, which are attached to the adjacent chains, are arranged in an alternate (staggered) pattern etc. so as not to overlap each other. In a widened part, excavation-orbit outer peripheral surfaces of the excavating blades, whose widths are greater than that of the chain, somewhat overlap each other, or at least come into contact with each other. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an underground continuous wall construction method and apparatus capable of constructing a wall thickness to a required thickness depending on a depth or the like.
[0002]
[Prior art]
In the case of excavating one side or excavating the inside like a mountain retaining wall, the rigidity at the top of the wall may be smaller than the rigidity at the bottom. The same is true when used as an underground foundation.
However, the wall thickness of the conventional endless chain cutter system is constant, and a considerable portion of the upper wall thickness is wasted.
Also, when constructing a continuous wall with a multi-axis machine, it is generally known that a portion having a thickness larger than the wall thickness is formed at the bottom of the continuous wall to increase the supporting force. It was impossible with the method.
In addition, the upper end of the cutter post is on the ground and is covered with a cover for the purpose of preventing scattering of excavated soil and the like and danger prevention. However, since the cover cannot be made extremely larger than the thickness of the cutter post or the diameter of the driving sprocket for that purpose, the width of the cutter or the width of the stirring plate has been limited to a size that can pass through the inside of the cover.
[0003]
[Problems to be solved by the invention]
Therefore, the waste of the wall thickness is omitted, the wall thickness with the strength required by the depth and the like and the construction of the underground continuous wall of the expanded bottom shape are possible, and the cost including the reduction of the solidified material due to the reduction of the unnecessary wall thickness is reduced. It is an object of the present invention to provide an underground continuous wall construction method and an apparatus thereof capable of reducing the number of underground walls.
[0004]
[Means to solve the problem]
As a means for solving the above problems, the present invention uses an endless chain cutter type horizontal excavator as a multiple chain type, using a cutter post having a tapered or expanded bottom shape in a section perpendicular to the excavation direction, and using each of the chains on the cutter post. Are made to orbit different trajectories with intermediate splots and / or chain guides. Also, the excavating blades attached to the adjacent chains are arranged alternately (alternately) so that they do not overlap, and the outer peripheral surfaces of the excavating orbits of the excavating blades wider than the chain width slightly overlap or at least contact with each other in the widened portion. The method and the apparatus for constructing a continuous underground wall having a tapered shape and a widened bottom shape are characterized in that:
[0005]
In this way, it is possible to construct an underground continuous wall having a tapered shape in which the cross-sectional shape at right angles to the excavation direction, that is, the wall thickness increases toward the bottom.
[0006]
Therefore, the wall thickness can be increased to the required strength depending on the depth, etc., and the waste of the upper wall thickness can be eliminated, so that the solidifying agent can be saved and the cost can be reduced. Wall construction becomes possible.
[0007]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described with reference to embodiments shown in the drawings.
[0008]
FIG. 1 shows one embodiment of a tapered continuous wall construction apparatus using a multiple endless chain cutter system used for carrying out the present invention, FIG. 1-1 is a front view thereof, and FIG. 1-2 is a side view thereof. is there. FIG. 2 is an enlarged view of the widened portion A of FIG. FIG. 3 shows cross-sectional shapes of various continuous walls which can be formed by the present invention at right angles to the excavation direction. (3-1) is of the two chains 7a and 7b type so as to have a cross section perpendicular to the direction of excavation of the continuous wall shown in FIG. 1. It is a vertical one. (3-2) is the same as that in FIG. 1 but shows that the more the number of the chains is increased by using three chains (not shown), the more naturally the wall thickness can be increased. It is a thing. (3-3) shows that a cross section perpendicular to the excavation direction can be formed into an expanded bottom shape with a three-chain (not shown) type. (3-4) shows that the cross section perpendicular to the digging direction can be formed in a beer barrel shape with the same three-chain (not shown) type, and that the width can be increased even in the middle. It is shown.
[0009]
In FIG. 1, the section perpendicular to the excavation direction is set to excavate a trapezoidal (FIG. 3-1) continuous wall. For this reason, the cutter post 5 viewed from the excavation direction has a rectangular parallelepiped ground portion and an underground excavation portion formed in the shape shown in FIG. A driving sprocket 8 at the upper end of the cutter post 5 is driven to rotate by a hydraulic motor 4 mounted coaxially, and a driven sprocket 10 is pivotally supported at the lower end of the cutter post 5. An intermediate splot 9 and / or a support (not shown) for restraining the trajectory of the chains 7a, 7b is provided so that the two chains 7a, 7b can orbit, and a cutting blade 6 is attached to these chains 7a, 7b. I have. The intermediate splat 9 and / or support (not shown) is provided at the starting point of the widened portion or the narrowed portion, and functions as a guide for changing the chain track.
[0010]
The excavating blades 6 attached to the chains 7a and 7b are larger than the chain width, and one side of the excavating blades 6 protrudes from the cutter post 5. When it is desired to increase the difference between the widened portion and the narrowed portion, the left and right sides are required. This is achieved by using an asymmetrical digging blade (not shown) that has a longer overlapping portion of the outer trajectory of the digging blade attached to a different chain than the symmetrical digging blade and has a shorter portion protruding from the cutter post 5 on one side. You.
[0012]
In addition, in the cutter post 5, a ground improving chemical such as cement milk is supplied from a liquid injection port 11 below the driving sprocket 8 at the upper end to a chemical spout (not shown) provided near the driven sprocket 10 at the lower end. There is provided an injection pipe (not shown) serving as a drug solution conduit communicating with the device, so that the drug solution can be discharged into the ground at any time.
[0013]
In addition, as a method of inserting a reinforcing material such as a reinforcing bar into the tapered continuous wall, for example, the length of the spacing member in the method of Japanese Patent No. 3377054 is shortened from the bottom to the top, so that it is completely folded. Even if it does not become a reduced state, the thickness of the low portion at the start of hanging can be reduced, so that it can pass through the thickness width of the upper wall, and a cage body having a tapered thickness can be finally inserted into the continuous wall.
[0014]
In addition, a mechanism for forming a continuous wall having a tapered shape or the like while making each cutter post on which the multiple chain is mounted a slide type and widening with a hydraulic piston or the like can be considered, but it is complicated and expensive, and is not practical.
[0015]
Next, the operation of the above embodiment will be described with reference to the example of FIG.
[0016]
The excavating blades 6 are alternately attached to the two chains 7a and 7b mounted along the outer periphery of the cutter post 5 configured so that the cross section perpendicular to the excavating direction has a tapered shape and the cut side surface is vertical, without overlapping. The bottom end of the cutting blade 6 is lowered along the leader 1 with the lifting cylinder 3 to lower the cutter post 5 to the ground at the starting position. Then, the hydraulic motor 4 is started, and the chains 7a and 7b are rotated via the driving sprocket 8. While moving, the cutter post 5 is lowered by the lifting cylinder 3 along the reader 1 to start excavation, and the cutter post 5 is erected to the set depth.
[0017]
Next, although not shown, a ground improvement chemical such as cement milk is fed from a surplus liquid recycling plant (e.g., an apparatus described in Japanese Patent Application Laid-Open No. 2001-271338) through the injection chemical supply port 11 below the upper drive sprocket 8. The crawler 2 is advanced toward the destination position while discharging from a chemical liquid discharge port (not shown) provided near the driven sprocket 10 at the lower end. The surplus mixed soil generated here is collected in the plant, and the soil improvement chemicals and the like in the surplus mixed soil are collected and used.
[0018]
When the cutter post 5 reaches the reaching position, the supply of the chemical solution is stopped, and the cutter post 5 is pulled up along the reader 1 and collected on the ground while rotating the chains 7a and 7b. Stop. Thus, a soil cement continuous wall groove having a trapezoidal cross section in the excavation direction from the start position to the arrival position is formed. The erection and lifting holes at the start position and the arrival position are formed as rectangular parallelepiped holes having an enlarged bottom wall thickness due to the structure of the apparatus.
[0019]
Although the explanation is omitted, the excavated sectional shape shown in FIG. 3 is also formed by the same method.
[0020]
【The invention's effect】
Since the wall thickness is required to be strong depending on the depth or the like, the unnecessary wall thickness can be reduced, the amount of the solidifying agent can be reduced, and the cost can be reduced.
In addition, as an application thereof, it is possible to construct an underground continuous wall having an expanded bottom.
Further, compared with the widened portion, the cover width for preventing the excavated soil from scattering and preventing danger can be smaller than the widened portion.
[Brief description of the drawings]
FIG. 1 is an explanatory view showing an embodiment of a construction machine according to the present invention. (1-1) is a front view, and (1-2) is a side view thereof.
FIG. 2 is an enlarged view of a widened portion A of FIG.
FIG. 3 is a cross-sectional view perpendicular to various excavation directions that can be constructed by the present invention. (3-1) is a sectional view of a tapered continuous wall by a double chain method, (3-2) is a sectional view of a tapered continuous wall by a triple chain method, (3-3) is a sectional view of an expanded bottom continuous wall, 3-4) is a sectional view of a via-barrel continuous wall.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Leader 2 Crawler 3 Elevating cylinder 4 Hydraulic motor 5 Cutter post 6 Drilling blade 7a, 7b Chain 8 Drive sprocket 9 Intermediate sprocket 10 Follower sprocket 11 Chemical liquid supply port

Claims (3)

In an endless multiple chain cutter type horizontal excavator, the multiple chain type is used, and a cutter post having a desired shape in a cross section perpendicular to the excavation direction is used, and each chain has a different trajectory on the cutter post with an intermediate splot and / or a chain guide. A method of constructing a continuous wall, such as a tapered shape, a widened bottom shape, or the like, which is characterized by being circulated. In an endless multiple chain cutter type horizontal excavator, the multiple chain type is used, and a cutter post having a desired shape in a cross section perpendicular to the excavation direction is used, and each chain has a different trajectory on the cutter post with an intermediate splot and / or a chain guide. A continuous wall construction device having a tapered shape, a widened bottom shape, etc., characterized by being circulated. 3. The taper according to claim 2, wherein the digging blades mounted on the individual chains are mounted in an alternating (alternating) arrangement so that the digging blades mounted on adjacent chains do not overlap. Continuous wall construction equipment such as shape, expanded bottom shape, etc.

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