JPH0473325A - Shaft excavator - Google Patents

Abstract

PURPOSE:To reduce labor and shorten the term of work in the settling of a caisson, and to improve the safety and accuracy of execution of work by excavating the bottom of the caisson by a machine with a freely movable cutter. CONSTITUTION:The lower section of a caisson 1 is manufactured on the ground, the arm 4 of an excavator 2 is inserted to a section lower than the opening section 7 of the bottom 1a of the caisson 1, and the jack of a fixed beam 3 is extended and the excavator 2 is fixed. The whole surface of the lower section of the caisson 1 is excavated while moving a cutter 17 by the arm 4. On the other hand, the caissons are extended by the construction of a wall body 1b with the lowering of the caissons 1. The caisson is settled up to specified depth, the fixed beam 3 is shrunk, the arm 4 of the excavator 2 is shrunk and folded, and all devices and members are recovered by a crane, etc. Lastly, concrete is placed in an excavating space 41 and the opening section 7 from a tremie pipe 12, thus completing the construction of a shaft caisson.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a shaft excavation device, and particularly to a shaft excavation device used in the caisson construction method.

[Prior Art] Conventional techniques for constructing vertical shafts using caisson construction methods include oven caisson construction method and pneumatic caisson construction method.

The oven caisson construction method opens the entire bottom of the caisson,
The ground inside the caisson is excavated and drained using a crumb packet, the caisson is lowered to a predetermined position, and a shaft is constructed.

In the pneumatic caisson construction method, a working chamber is provided below the caisson, compressed air is sent into the working chamber to increase the atmospheric pressure, and water such as groundwater is removed from the working chamber. and,
A worker enters the work room and excavates the ground below the caisson to sink the caisson and construct a shaft.

[Problems to be Solved by the Invention] In the conventional oven caisson construction method described above, a crumb packet is dropped into a caisson to excavate the ground, and the crumb packet is pulled up to discharge the earth and sand inside the crumb packet. Therefore, since the ground is excavated and then discharged, the process is serial and requires a long construction period.

On the other hand, in the pneumatic caisson construction method, excavation is performed by a worker, so excavation control can be easily performed, and excavation and soil removal can be performed in parallel.

However, manual excavation requires a great deal of time and effort. Furthermore, there are limits to work in high pressure, which limits the construction of vertical shafts and exposes workers to risks and dangers such as caisson disease.

In addition, the area to be excavated in both cases cannot be expanded beyond the bottom of the caisson; for example, if only the coefficient of friction between the caisson on the negative side and the ground becomes large, the caisson may tilt and sink, resulting in poor construction accuracy. This causes problems.

Therefore, when constructing a vertical shaft, we unmanned the laying of caissons.
In order to reduce labor, improve safety, and shorten the construction period through mechanization, technical problems arise that must be solved in order to improve construction accuracy, and the present invention aims to solve these problems. purpose.

Means for Solving the Problem] This invention was proposed to achieve the above object, and the arm base of an excavator, which is composed of a link mechanism, a rotating shaft, etc., is fixed to the lower part of the caisson. The arm is provided with a cutter that protrudes downward from the open part of the bottom of the caisson, and is provided with a cutter driven by a motor or the like at the tip of the arm so that the cutter can freely move below the caisson. It is an object of the present invention to provide a shaft excavation device characterized in that it is equipped with a mud feeding port for pumping muddy water downwardly of the caisson, and a mud draining port for pumping muddy water to the cutter.

[Operation] In this invention, the arm of an excavator is constructed of a link mechanism and a rotating shaft, and a cutter provided at the tip of the arm excavates the ground while moving below the caisson. Further, the earth and sand generated by the excavation is liquefied and slurried by the muddy water pumped through the mud feeding port, and is discharged from the mud draining port of the cutter.

Therefore, the caissons are sunk as the ground is excavated.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 1 and 7 of the attached drawings. In the figure, (1) is a caisson, and as shown in FIG. 1, an excavator (2) is provided at the bottom of the caisson (1). The excavator (2) is attached by pressing the fixed beam (3) of the excavator (2) against the inner surface of the lower part of the caisson (1). The fixed beam (
3) has a jack (not shown) inside and is configured to be expandable and retractable. At the center of the fixed beam (3) is the excavator (
The rotating shaft (5) of the arm (4) of 2) is pivotally connected. That is, as shown in FIGS. 1 and 2, the rotating shaft (5) is pivotally supported by a rotating device (6) fixed at the center of the fixed beam (3), and is rotated in the horizontal direction. , the rotating shaft (5) is suspended from the opening (7) of the caisson bottom (1a). The rotating shaft (5)
The center part of the first arm (8) is pivotally attached to the lower end of the
The base of a second arm (9) is pivotally connected to the tip of the first arm (8). A protrusion Qo) is formed on the side of the base of the second arm (9), and the protrusion 00)
A link arm 01) is pivotally attached to.

In addition, a triangular drag link (one end of ■) is pivotally attached to a portion slightly rearward of the tip of the first arm (8), and
A link arm (11) is attached to the other end of the drag link.
It is pivoted at one end. Furthermore, the base of a hydraulic cylinder (1) is pivotally connected to the upper part of the rotating shaft (5), and the base of the hydraulic cylinder (1st class cylinder rod) is pivotally connected to the rear part of the first arm (8). The first arm (8) is configured to be able to move up and down by the expansion and contraction of the hydraulic cylinder (+3).
), the base of another hydraulic cylinder (1) is pivotally connected to the rear of the cylinder rod (10
is pivotally connected to the center of the drag link (1) so that the second arm (9) can be vertically rotated with respect to the first arm (8) by means of a hydraulic cylinder (1). On the other hand, there is a cutter (0) at the tip of the second arm (9).
A bracket fixedly attached to the cutter (one end of the cutter is pivotally connected to the bracket).Furthermore, a drag link (A) is pivotally attached to the bracket fixedly attached to the intermediate portion of the second arm (9), (b) The upper end of the bracket (0 and the drag link (
Both ends of the link arm (2+) are pivotally connected to the tip of the link arm (2+). Further, a hydraulic cylinder (to) is pivotally connected to the base of the second arm (9), and the hydraulic cylinder (2)
Connect the cylinder rod (c) to the drag link (a).
It is configured so that the cutter (■) can be rotated downward by L by the expansion and contraction of the hydraulic cylinder (X). At the same time, a blade (
The motor (E) is configured to be rotatable in the horizontal direction, and the motor (
By driving c), the blade (E) is rotated via a gear (not shown) in a gear box (b). Thus, as shown in Figures 1 and 3, the excavator (2)
) and the respective hydraulic cylinders θ■ (■ (to)).
The arm (4) is configured to be able to move forward and backward in any direction, and the arm (4) is configured to be expandable and contractible. On the other hand, although not shown, a muddy water treatment facility is installed on the ground, and the muddy water treatment facility connects the caisson bottom (Ia).
The mud feeding pipe (A) is extended to the lower surface of the mud pipe to form a mud feeding slope of 0. The muddy water is then pumped through the caisson (+
) is configured so that it can be fed under pressure. Further, a mud drain port (a) is provided at the lower center of the cutter (no), and muddy water is drained into the drain port (4) by operating a drain pump (g) provided above the fixed beam (3). The structure is such that mud can be drained from the muddy water treatment equipment through a drain pipe [phase] (31) and a rotary joint (2), etc. In addition, the symbol (c) in the figure is a cable, and the cable ( (to) drive the cutter (7), rotate the rotary shaft (5), operate the drain pump, and operate the respective hydraulic cylinders (II (
A) is a power line for operating the @ solenoid (not shown), and (b) is a cable for sending control signals. And (32a) and (32b) are the rotary joints of these cables @ (b), and (c) is the cable (
C) (B) is the connector, and (A) is the hydraulic pump unit. Further, (A) is a cover, and this cover (B) is fixed to the lower part of the fixed beam (3), and the opening (7) of the caisson bottom (11) is provided at the peripheral edge of the cover (B). )
A locking groove (37a) facing the inner peripheral surface is formed. Then, the air tube (to) is fitted into the locking groove (37a) and pressed against the inner peripheral surface of the opening (7), and the air tube (to) is pressed against the inner peripheral surface of the opening (7).
The opening (7) is covered by the air tube (to) and the air tube (to).

Therefore, when constructing a shaft, as shown in Figure 4,
The surface ground (a) is excavated and the lower part of the caisson (+) is constructed on the excavated ground (b). In addition, (D) in the figure is the earth retaining. Then, as shown in Fig. 5, the excavator (2
) and the arm (4) are retracted and the arm (4) is inserted downward through the opening (7) in the caisson bottom (1a). The state of contraction of this arm (4) is the second
The hydraulic cylinder 0■ shown in the figure is extended to place the first arm (8) in an upright state. Then, the second arm (4) is rotated downward by extending the hydraulic cylinder 0→, and the arm (4) is rotated upward by extending and contracting the hydraulic cylinder (c). is folded and contracted.

Then, the jack of the fixed beam (3) is extended to fix the excavator (2).

Next, as shown in Fig. 1, while moving the cutter using the arm (4), excavate the entire area below the caisson (1). Mud water is pumped, and the earth and sand generated by excavating the ground is liquefied or slurried and discharged from the mud drainage port (A) of the cutter (No. ) can adjust the mud water pressure in the excavation space (41).On the ground, on the ground, a formwork (42) is provided at the upper end of the caisson (1) and the wall (1b) of the caisson (1) is )
is constructed. Therefore, the caisson (1) is extended while descending. In addition, the code (43) in the figure is the ballast water injected into the caisson (1), and the ballast water (43) is injected into the caisson (1).
), the load on the caisson (1) is increased to ensure a smooth descent of the caisson (+).

Then, as shown in FIG. 6, after the caisson (1) has been extended to a predetermined depth, the fixing beam (3) is retracted to release the fixation of the excavator (2). Furthermore, the arm (4) of the excavator (2) is contracted and folded in the same manner as described above, and the excavator (2) is recovered using a lifting machine or the like.

Thus, as shown in FIG. 7, the tremor pipe (44) is inserted into the caisson (1), concrete is poured into the excavation space (41) and the opening (7), and a shaft is constructed.

Note that this invention can be modified in various ways without departing from the spirit of the invention, and it goes without saying that this invention extends to such modifications.

[Effects of the Invention] As described in detail in the above-mentioned embodiment, this invention excavates the lower part of a caisson with a cutter, and converts the earth and sand generated by the excavation into a liquid or slurry form using mud water pumped through a mud feeding port. Since it is configured so that mud can be drained from the mud drainage port, the lowering of the caisson can be automated and mechanized, eliminating the risk of caisson disease even when constructing a deep shaft. At the same time, it is possible to reduce labor and shorten the construction period.

Further, since the arm of the excavator that excavates the lower part of the caisson is configured to be expandable and retractable, the arm can be assembled on the ground and attached to the bottom of the caisson, or it can be recovered to the ground without disassembling it. Moreover, since the cutter installed at the tip of the arm is configured to be movable below the caisson by the arm, the efficiency of ground excavation can be improved by, for example, intensively excavating the hard surface of the ground. can do. Further, since the excavator can excavate the area under the caisson in any shape, the square shape in plan view can be used by being attached to a caisson having a circular or polygonal shape, thereby increasing versatility. Furthermore, by adjusting the excavation area below the caisson, the coefficient of friction between the caisson and the ground can be adjusted and the caisson can be prevented from tilting, so the caisson can be built vertically to improve construction accuracy. can be improved.

On the other hand, the cutter installed at the tip of the excavator's arm rotates a small diameter blade to excavate the ground, making it possible to excavate the ground with less power; it also contributes to reducing stress, etc. This invention has remarkable effects.

[Brief explanation of drawings]

The figures show one embodiment of the present invention; FIG. 1 is a partially cutaway sectional view showing the caisson with an excavator attached and the caisson extended; and FIG. 2 is an enlarged partially cutaway sectional view of the same. , Figure 3 is an enlarged sectional view of the main parts showing the excavator arm in the retracted state, Figure 4 is a sectional view showing the lower part of the caisson set on the ground, and Figure 5 is the excavator set on the lower part of the caisson. Fig. 6 is a partially cutaway sectional view showing the condition in which the excavator is recovered after the caisson has been constructed, and Fig. 7 is a partially cutaway sectional view showing the condition in which the excavator is recovered after the caisson has been constructed. It is a partially cutaway sectional view showing the state. (1)...Caisson (2)...Excavator (8)...First arm Q +)...Link arm (r?) --- Cutter Qf) --- Sludge inlet (1a) --- Caisson bottom (5) --- Rotating shaft (9) ---- Second Arm (■...Drag link (G) - Motor (A)...Mud removal port

Claims (1)

[Claims] The base of the arm of the excavator, which is composed of a link mechanism, a rotating shaft, etc., is fixed to the lower part of the caisson and protrudes downward from the open part of the bottom of the caisson, and a cutter driven by a motor, etc. is provided at the tip of the arm. The cutter is configured to be able to freely move below the caisson, and is provided with a mud feeding port in the lower part of the caisson for pumping muddy water to the bottom of the caisson, and a mud draining port for pumping muddy water to the cutter. A vertical shaft excavation device featuring: