JP2767021B2 - Open caisson laying method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides a hollow chamber capable of storing water in a body, gradually adjusting the amount of water stored in the hollow chamber to balance the self-weight and buoyancy of the body, and gradually moving the body into the ground. This is related to the method of submerging an open caisson.

[0002]

2. Description of the Related Art Conventionally, this type of open caisson includes:
For example, there is one described in JP-A-61-207726. This open caisson has been adopted to make it easier to handle by reducing the weight, and to prevent unequal settlement from suddenly sinking.The inner wall and outer wall closed at the lower end are integrated with concrete to make it A double-shell structure is formed, and a cavity is formed between each of the inner and outer walls to reduce the weight of the skeleton to less than buoyancy.

Then, water having a weight substantially corresponding to the difference between its own weight and buoyancy is sequentially injected into the hollow chamber according to the immersion depth, so that the cylindrical body is gradually sunk while being balanced with buoyancy. . In addition, the open caisson after being laid, for example, when excavating a subway tunnel,
Used for underground multi-story parking lots.

[0004]

However, since the open caisson has a double shell structure of an inner wall and an outer wall, the internal space of the momentum is narrowed, and when the caisson is used as the above-mentioned vertical hole or a multi-story parking lot after being laid, There was a problem that it was difficult to effectively use.

Further, since the inner wall is formed integrally with the outer wall and the concrete, and a plurality of ribs are provided between the inner wall and the outer wall, these forming frames are complicated, and much time is required for assembling work. There was a problem that it took a lot of time and effort, and the construction cost became high. Therefore, an object of the present invention is to solve all of the problems found in the prior art, and a sunk open caisson that can be used widely and effectively and can easily be molded. To provide a construction method.

[0006]

According to the present invention, there is provided a method of submerging an open caisson according to the present invention, in which a flange is integrally provided on an inner peripheral surface of a cylindrical outer wall, and the flange is formed integrally with the outer wall. An opening is provided in the center, and a lower open end is provided on the upper surface of the flange to form a cylindrical inner wall surrounding the periphery of the opening, and an empty space closed between the inner wall and the outer wall by the flange. To form the torso,
In the method of submerging an open caisson in which water is sequentially injected into the cavity chamber and the amount of water stored therein is adjusted to balance the self-weight and buoyancy of the frame while gradually penetrating and sinking the frame into the ground, The inner wall was formed by a steel pipe, the lower end of the steel pipe was joined to the upper surface of the flange, and the steel pipe was removed after the skeleton was laid down.

[0007]

[Function] By increasing or decreasing the amount of water stored in the cavity formed in the body of the open caisson, it is possible to set the blade load corresponding to the supporting force of the ground at the body edge, and to increase the amount of water stored in the cavity. By doing so, the load on the cutting edge is made larger than the supporting force of the ground on the cutting edge of the skeleton, and the skeleton is gradually lowered. Then, after submerging, the inner wall is removed to expand the internal space. Thereby, the inside can be widely and effectively utilized as, for example, a multi-story parking lot. Further, since the inner wall is made of a steel pipe and is erected so as to be detachable, it is extremely easy to form the inner wall.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the method for laying an open caisson according to the present invention will be described below with reference to the drawings. FIG. 1 shows a state in which an open caisson is submerged in the ground, S indicates the surface of the ground, and W indicates the water level. In the figure, reference numeral 1 denotes a cylindrical body formed of concrete and having upper and lower end faces opened. A flange 3 is integrally provided on an inner peripheral surface of a lower end portion of an outer wall 2 and a center of the flange 3 is provided. An opening 4 is provided through the opening.

Further, the cylindrical inner wall 5 where the upper bottom is open to the upper surface of the flange portion 3 is an open end of the lower surrounding the said opening 4
Is erected. The inner wall 5 is formed of a steel pipe. As shown in FIG. 3, a flange 6 is provided on the outer periphery of the lower end, and a plurality of bolt insertion holes 7 are formed in the flange 6. On the other hand, a plurality of bolts 8 are erected on the periphery of the opening 4 in the flange 3. Then, each of the bolt insertion holes 7 is fitted to the bolt 8, a packing 9 is further interposed between the flange portion 3 and the flange 6, and the nut 10 is tightened to attach the inner wall 5. As a result, a cavity 11 closed between the outer wall 2 and the inner wall 5 by the flange 3 is formed.

The hollow chamber 11 is set within a range where the buoyancy does not become larger than the own weight of the frame 1, and the water is stored therein to increase the weight of the frame 1. The hollow chamber 11 is provided with a pipe 13 connected to a water source via a pump 12, and the pump 12 is operated to adjust the increase or decrease of the water storage amount. Further, the balance between the weight of the frame 1 and the reaction force of the cutting edge, the adjustment of the water storage amount, and the lowering position of the frame 1 are all controlled by a control device (not shown).

Next, a method of laying the open caisson will be described. First, a skeleton 1 having a predetermined length is erected on the surface S of the ground, and then the skeleton 1 is left under its own weight while excavating the ground with an excavator (not shown) attached to a lower end thereof.
To sink. Then, the frame 1 stops at a position where the balance between the own weight and the buoyancy is balanced. In this state, pump 1
2 is operated to store water in the cavity 11, and water having a weight substantially corresponding to the difference between the load on the cutting edge of the caisson and the ultimate supporting force of the ground on the cutting edge is sequentially injected in accordance with the sinking depth. Then, the skeleton 1 is lowered to a predetermined position while excavating the ground.

The predetermined position is a position where the next skeleton can be joined to the upper end of the skeleton 1, that is, the upper end of the skeleton 1 protrudes above the ground surface S by a required length. Then, the next inner wall 5a is joined to the upper end of the inner wall 5 as shown in FIG.
The bolt insertion holes 15, 7a of the flange 6a provided on the outer periphery of the lower end of a are aligned, the packing 9 is interposed, the bolt 8 is inserted, and the nut 10 is tightened. Thereafter, the same operation is repeated. In this manner, the inner walls 5, 5a are removably joined.

After the open caisson is sunk to a predetermined depth, concrete is struck below the flange 3 and the cavity 11
And the water in the inner wall 5 is drained. Then, the inner wall 5 is removed by removing the bolts 8 and the nuts 10. As a result, as shown in FIG. 5, a large space is obtained in the open caisson, which is widely used as a space for constructing, for example, a multistory parking lot, a vertical hole for digging a subway tunnel, or an underground building. Available to

The removed inner wall 5 can be reused at the time of the next construction work of the open caisson.

[0015]

Sinking method Open caisson of the present invention as above mentioned, according to the present invention is, since the so joined in detachable preparative inner wall, it is possible to widely expand the skeleton body by removing the inner wall after sinking, This enables effective use as a vertical hole when digging a multilevel parking lot or subway tunnel.

Further, since the inner wall is formed as a temporary body, there is no need to form a mold for the inner wall, and the molding of the open caisson is facilitated, thereby shortening the construction period and reducing the construction cost. In addition, since the inner wall of the open caisson is removed after subsidence, the weight of the open caisson is very light.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a method of laying an open caisson according to the present invention.

FIG. 2 is a sectional view taken along line XX in FIG.

FIG. 3 is an enlarged sectional view of a joint at a lower end of an inner wall.

FIG. 4 is an enlarged sectional view of a joint at an upper end of an inner wall.

FIG. 5 is a longitudinal sectional view of the open caisson after being laid down.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Frame 2 Outer wall 3 Flange 4 Opening 5 Inner wall 11 Cavity room

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-2-112525 (JP, A) JP-A-3-13628 (JP, A) JP-A-61-207726 (JP, A) JP-A-3-112 253615 (JP, A) JP-A-3-28421 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) E02D 23/08

Claims (1)

(57) [Claims] 1. A flange is integrally provided around an inner peripheral surface of a cylindrical outer wall, and an opening is formed in the center of the flange. A lower open end is formed on an upper surface of the flange by the opening. A cylindrical inner wall surrounding the periphery of the container is erected, a cavity is formed between the inner wall and the outer wall, and is closed by a flange, and water is sequentially injected into the cavity and the amount of water stored therein is adjusted. In the laying method of an open caisson in which the skeleton gradually penetrates and sinks into the ground while balancing the self-weight and buoyancy of the skeleton, the inner wall is formed by a steel pipe, and the lower end of the steel pipe is formed on the upper surface of the flange. An open caisson laying method, characterized in that the steel pipe is removed after the skeleton is laid down.