JPS6143496B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of constructing a caisson work chamber and an earth and sand center used in this construction.

Conventionally, when constructing a caisson using an earth and sand center, the earth and sand center is first created by embankment on the ground at the location where the construction is to be performed, then the first frame of the caisson is formed on this earth and sand center, and then this skeleton is Initial excavation is performed manually using the shaft hole of the earth and sand center, a working hole is created in the earth and sand center, the excavation machine parts that are lowered through the shaft hole are assembled in this work hole, and after assembly, the earth and sand center is mechanically excavated. A work room was to be constructed below the first frame. However, according to this construction method, a working hole is manually excavated as the initial excavation, so there is a problem in that it takes time and manpower to perform mechanical excavation.

An object of the present invention is to simplify the construction work of a working hole, thereby saving labor and speeding up the work up to mechanical excavation.

In the construction method of the present invention, a temporary buried support such as a sand-filled can is embedded in advance inside the center at a position opposite to the lower part of the shaft hole of the caisson to be constructed as an earth and sand center.
This buried support has a size and weight that allows it to be taken out of the first frame through the shaft hole. The construction method is to first construct the first frame of the caisson on top of the earth and sand center, then use the shaft hole of this first frame to pull up the embedded supporting body above the frame. A hole is created in the earth and sand center, this hole is used as a work hole, and an excavation machine is assembled inside this hole, and then the earth and sand center is excavated by mechanical excavation, etc., and a work room is constructed below the first frame. It is something.

An embodiment of the present invention will be described below based on the drawings.

First, a specific configuration of the earth and sand center according to the present invention will be explained, and then a method of constructing a work room using this earth and sand center will be explained.

In Figures 1 and 2, the earth and sand center 1 is constructed by embanking to a height of 2 m on the ground. Inside this earth and sand center are shaft holes 2a and 2b of the first frame 2 of the caisson which are received on the outer surface of the center.
A predetermined number of sand-filled cans 3 as temporary burial supports are embedded in advance at a position facing the . In other words, at a position facing the shaft hole 2a used by the worker,
9 cans of sand 3...but 5 on the bottom shelf and 4 on the top shelf
20 sand cans 3 are buried in piles with books, 10 each in the upper and lower tiers, in a position facing the shaft hole 2b used as a transportation path for excavation machine parts, etc. It is buried in good condition.

The sand-filled can 3 has a height of approximately
It is shaped like a drum with a diameter of 900 mm and an outer diameter of approximately 550 mm, and is filled with sand. Reinforcing bars 4 and 4a are welded to the outer surface of the sand can in the vertical and horizontal directions, respectively, and the reinforcing bars 4 in the vertical direction are somewhat thicker than the reinforcing bars 4a in the horizontal direction.
A hanging string 5 made of wire is attached to the upper end of the sand can 3.
is installed.

The outer surface of the earth and sand center 1 is made of waste concrete 6
It is covered with.

Note that the cutting edge on the outer periphery of the first frame 2 is supported on a pile 7 driven into the ground G.

Next, the construction method for the work room of the first frame will be explained together with the construction work for the earth and sand center.

First, the first frame 2 of the caisson to be constructed,
The sand-filled cans 3 are stacked one after another in two places on the ground G facing the shaft holes 2a and 2b, and then the sand-filled cans are buried with embankment (Fig. 5), and then the outer surface of the embankment is The construction of the earth and sand center 1 is completed by pouring concrete 6 to cover the outer surface.

Then, as shown in FIG. 1, a formwork is assembled on the earth and sand center 1, reinforcement is arranged, and concrete is poured to form the first frame 2 of the caisson. after that,
Using the shaft holes 2a and 2b provided in this first body, a crane sequentially moves sand-filled cans 3... to the first
Take it out of the body. When taking out the first one or two cans, if you use a jet in the gap between the cans to remove the dirt stuck in the gap between the cans, it will be easier to pull them up. If all the sand cans 3 are pulled up, there will be a 6th can in two places in the sand center 1.
As shown in the figure, working holes 1a and 1b are formed at positions facing each shaft hole 2a and 2b, respectively. After excavating and leveling the ground in and around each work hole as necessary, unload the excavation machine parts etc. into the work hole 1b from one shaft hole 2b, assemble the machine, and then input it with the excavation machine as necessary. By excavating the earth and sand center 1, a working chamber 8 is formed below the first frame 2, as shown in FIG.

Note that if a drum-shaped can is used as the sand-filled can 3, it is inexpensive and the stacking and removal work can be done quickly. . The number of cans
It can be selected as appropriate depending on the height of the earth and sand center, the size of the first frame of the caisson, etc. Of course, the temporary burial support is not limited to a can, but may also be a sandbag or the like.

As explained above, according to the present invention, there is no need to construct a working hole by manual excavation as in the past, so the construction work of this working hole can be simplified, and therefore, the work hole can be used for mechanical excavation. It is possible to save labor and speed up the work until the process is completed. Furthermore, it is possible to save earth and sand for embankment in an amount equivalent to the volume of the temporary burial support.

[Brief explanation of the drawing]

Figure 1 is a longitudinal sectional view showing the construction state, Figure 2 is a plan view of Figure 1, Figure 3 is a front view of the sand can, and Figure 4 is a front view of the sand can.
The figure is a cross-sectional view taken along the lines shown in Figure 3, Figure 5 is a cross-sectional view showing the sand canister buried, Figure 6 is a cross-sectional view showing the sand canister removed, and Figure 7 is the state where the work chamber has been constructed. FIG. 1... Sediment center, 1a, 1b... Working hole,
2...First body, 2a, 2b...Shaft hole, 3
...Sand can, 5...Hanging string, 8...Work room.

Claims (1)

[Scope of Claims] 1. A first frame of the caisson is constructed on the earth and sand center, and then a temporary burial support embedded inside the earth and sand center at a position facing the shaft hole provided in the first body is installed as described above. The shaft hole is used to take out the first frame using a crane, etc., and the hole created in the earth and sand center by the removal of this temporary buried support is used as a working hole, and excavation such as mechanical excavation is carried out in this hole. A method of constructing a caisson working room, characterized in that the working room is formed below the first frame. 2 A temporary buried support is embedded inside the earth and sand center at a position opposite to the shaft hole of the first frame of the caisson to be constructed, and this temporary buried support can be taken out of the first frame through the shaft hole. An earth and sand center used in the construction of a caisson work chamber characterized by having the size and weight of 3. The earth and sand center according to claim 2, wherein the temporary burial support is a drum-shaped sand-filled can to which a hanging string is attached.