JPH0441727B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a caisson having a joint and a method for sinking the same.

<Object of the present invention> An object of the present invention is to provide a caisson having the following joint and a method for sinking the same.

<A> A caisson with a joint and its sinking method, which allows the caisson and the joint to be sunk as one, reducing the number of work steps and shortening the construction period.

<B> A caisson with a joint and its sinking method that allows easy and reliable connection between caissons.

<Structure of the present invention> An embodiment of the present invention will be described below with reference to the drawings.

<A> Structure of the device of the present invention (FIGS. 1 to 3) In this embodiment, a case of a round caisson will be explained.

Note that a square caisson can also be used.

The caisson 1 of this device has an excavator 2 such as a reverse machine at the cutting edge of the excavation, injects water into the caisson 1, excavates while mixing earth and sand, and releases the excavated earth and sand to the outside. It is a structure that discharges water.

(1) Joint box The caisson frame 11 is attached to both ends of the outer surface of the caisson frame 11 of the caisson 1 in the caisson connection direction.
Two strip-shaped joints 3, 3 are attached at a constant interval in the horizontal direction from the upper end side to slightly above the lower end.

The lower ends of the joints 3, 3 are cut diagonally upward from the base end toward the free ends 31, 31.

Between the free ends 31, 31 of the joints 3, 3,
A rectangular partition plate 61 with water jet nozzles 5, 5 attached to its lower end is removably mounted horizontally using L-shaped steel or the like.

This partition plate 61 is placed horizontally over the entire length of the free ends 31, 31 of the joints 3, 3.

Then, a joint box 6, which is a box without a bottom cover, is formed.

Note that the free ends 31, 3 of these joints 3, 3
1 is attached with submerged guides 32, 32, each of which has a partially open side surface of a steel pipe.

(2) Earth and sand intake port A sand intake port 4 is opened in the caisson frame 11 at the lower end of the joint box 6 and directly above the excavator 2.

The earth and sand intake port 4 opens obliquely downward toward the inside of the caisson 1 and has a rectangular cross section so that its upper surface 41 becomes an extension surface of the space formed at the lower end of the joint box 6.

The point is that the excavated earth and sand can be taken in by a high-speed fluid such as water or air that is injected diagonally downward from water jet nozzles 5, which will be described later.

(3) Water jet nozzle The water jet pipes 51 are attached to both ends of the long side of the partition plate 61, and the water jet pipe 5 is attached to the lower end of the partition plate 61.
Attach the water jet nozzles 5, 5 connected to 1, 51.

The water jet nozzles 5, 5 are short nozzles and are installed diagonally downward so that they can easily take in the earth and sand into the caisson 1 by injecting high-speed fluid to excavate the earth and sand in front.

In other words, water jet nozzle 5,5
The structure is such that high-speed fluid is injected toward four directions of the earth and sand intake ports located diagonally below the earth and sand intake port.

<B> Method for sinking a caisson (Figures 1 to 4) Before the actual excavation of the caisson 1, normal work is carried out, and then excavation using a water jet is started.

(1) Excavation by water jet First, the first caisson 1 is sunk.

At the same time when the main body of the caisson 1 starts excavating by the excavator 2 at the lower end, high-speed fluid is injected from the water jet nozzles 5, 5 to excavate earth and sand in front of the lower end of the joint box 6.

The excavated earth and sand is taken into the caisson 1 through the earth and sand intake port 4, and is discharged to the outside together with the earth discharged by the excavator 2.

(2) Removal of the partition plate After completing the excavation of the first caisson 1, in the case of the second caisson 1, remove the already sunken caisson 1 and each sunken guide 3.
2 and 32 are connected and inserted in the correct direction.

When the excavation is completed, connect the connected sinking guide 3
The residual soil 7 remaining in the space surrounded by 2 and 32 and the respective partition plates 61 and 61 is removed by an earth removal pump or the like.

After that, each partition plate 61, 61 is removed.

(3) Installation of reinforcing bar cage in joint part Reinforcing bar cage 8 is inserted into the space of the joint part created by removing the partition plates 61, 61.

Then, concrete is poured into the joints to install strong joints 3, 3.

Other Embodiments 1 (Fig. 5) A dedicated soil removal pipe 9 for discharging excavated earth and sand at the lower end of the joint is installed inside the caisson frame 11 so as to cover the earth and sand intake port 4, and the caisson frame 1
An air lift air supply pipe 91 is buried in the interior of the air lift pipe 91.

It is also conceivable to inject air from the air lift air supply pipe 91 to discharge the earth and sand to the outside through the earth discharge pipe 9.

Other Embodiments 2 (Fig. 6) If the wall thickness of the caisson frame 11 is thick or the length of the joints 3, 3 is long, and it is not possible to take in sufficient excavated earth and sand, the caisson frame 1
It is also conceivable to further attach a water jet nozzle 52 to the upper surface 41 of the earth and sand intake port 4 inside the earth soil intake port 4, and to discharge soil using the two water jet nozzles 52.

<Effects of the Present Invention> Since the present invention has been described above, the following effects can be expected.

<A> Earth and sand in front of the lower end of the joint box can be excavated by the water jet nozzle attached to the lower end of the partition plate.

Therefore, the joint can be easily dug, and the caisson and the joint can be sunk together.

Therefore, the number of work steps can be reduced and the construction period can be shortened.

<B> Since the caisson and the joint can be sunk together, the joint can be attached to the caisson in advance.

Therefore, the caissons can be easily connected.

<C> A partition plate is attached to the joint, forming a box.

Therefore, earth and sand will not enter between the joints, and even if concrete or the like is poured into the joints, no earth and sand will be mixed in, resulting in a strong joint.

Therefore, caisson-to-caisson connection can be ensured.

[Brief explanation of drawings]

Figure 1: An explanatory diagram of an embodiment of the present invention, Figure 2:
An enlarged explanatory view of the lower end of the joint box, Fig. 3: An explanatory cross-sectional view of the joint part, Fig. 4: An explanatory view of a state in which a reinforcing bar basket is attached, and Figs. 5 and 6: An explanatory view of other embodiments.

Claims (1)

[Scope of Claims] 1. In a caisson having an excavator at the lower end of a hollow part penetrating in the vertical direction, at both ends of the outer surface of the caisson frame in the caisson connection direction, from the upper end side of the caisson frame to slightly above the lower end, a horizontal Two strip-shaped joints installed at regular intervals in the direction, an earth and sand intake port opened in the caisson frame directly above the excavator at the lower end of the joint, and a horizontal suspension between the free ends of the joints. A caisson having a joint, comprising a removable partition plate with a water jet nozzle attached to the lower end thereof, and the water jet nozzle is configured to direct high-speed fluid toward the earth and sand intake port. . 2 In a method of sinking a caisson with an excavator at the lower end of a hollow part penetrating in the vertical direction, a caisson is installed at both ends of the outer surface of the caisson frame in the caisson connection direction, from the upper end of the caisson frame to slightly above the lower end in the horizontal direction. Two strip-shaped joints are attached at regular intervals, and a water jet located at the lower end of a removable partition plate suspended horizontally between the free ends of the joints removes dirt and sand from the front of the lower end of the joints. The excavated earth and sand were taken into the caisson frame through the earth and sand inlet opened in the caisson frame at the lower end of the joint and directly above the excavator as the excavation progressed. After the excavation was completed, the partition plate was removed and the caisson and caisson were separated. A method for sinking a caisson with a joint, which is characterized by installing a reinforcing cage at the joint between the two and pouring concrete at the joint to sink the caisson.