JPH05118043A - Caisson sinking method by dividing the blade opening - Google Patents

Abstract

(57) [Summary] [Purpose] To facilitate the control of caisson deposition even on ground with a high N value. [Structure] A plurality of divided blade openings 5 and a sinking frame 12 fixed via the plurality of blade openings 5 and a jack 31.
And a vibrator 30 that is arranged so as to be able to move in and out of a space 27 formed in the sinking skeleton 12 and that vibrates the blade opening 5,
The plurality of blade openings 5 are divided into several sets of blocks, and when excavating the blade opening portions and press-fitting the blade openings in sequence for each block, the sinking skeleton is sunk while vibrating the blade openings.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a caisson laying method used for an underground skeleton foundation structure in civil engineering and construction.

[0002]

2. Description of the Related Art As an example of a conventional caisson digging method, an example of an open caisson will be described with reference to FIG. FIG. 1A shows a ground anchor press-fitting method, in which the ground anchor 1 is preliminarily constructed in the ground, the ground anchor 1 is passed through the sinking skeleton 2 with the jack 3, and the jack 3 is extended to extend the ground anchor 1. 2 as a reaction force
It is a construction method of sunk. Further, FIG. (B) shows a loading press-fitting method, in which the support pile 4 is preliminarily constructed in the ground and the support pile 4 is installed.
The jack 3 is arranged between the sinking structure 2 and the
Is a construction method in which the sinking skeleton 2 is sunk by using the support pile 4 as a reaction force by extending the slab.

Conventionally, especially in the open caisson method, it is difficult to excavate the tip of the cutting edge, and as can be seen from the difference in the peripheral frictional force between the open caisson and the pneumatic caisson, the tip supporting force and the peripheral frictional force can be understood. It was not possible to distinguish the sinking resistance caused by, and it was judged empirically. Since the subsidence of the caisson depends on the increase of its own weight and the decrease of the lifting pressure, the caisson inclination can be controlled only to some extent by the excavation method. When unequal subsidence of caisson occurs, there is a problem that heaving that causes soil that enters from the outside into the root cutting surface and raises the bottom surface, and boiling that moves soil particles due to head pressure. is doing.

However, in the method of press-fitting the caisson by using another support as a reaction force like the above-mentioned conventional earth anchor press-fitting method and load press-fitting method, temporary construction work becomes large in case of constructing deep ground, In addition, since there is no basis for bearing capacity against the increased load when constructing the subsided skeleton, and settlement control mainly relies on the intuition of field experience personnel, it is difficult to control settlement such as sudden settlement, and safety measures and construction There was a process problem.

[0005]

In order to solve the above problems, the inventors of the present invention disclosed in Japanese Patent Application No. 62-63183.
We have proposed a caisson sinking method by dividing the blade opening that can surely control the sinking of the caisson and prevent the heaving or boiling. This will be described with reference to FIGS. 5, 6 and 7.

FIG. 5 shows a state in which the blocks of the plurality of blades 5 are connected in a rectangular shape. As shown in FIG. 6, the blade opening 5 horizontally attaches and fixes a pressure plate 7 to a vertical outer guide plate 6, and fixes a plurality of lower ribs 9 over the lower surface of the pressure plate 7 and the outer guide plate 6. At the same time, a plurality of upper ribs 10 and inner guide plates 11 are attached and fixed to the upper surface of the pressure plate 7.
The sinking skeleton 12 is constructed between the outer guide plate 6 and the inner guide plate 11 of the blade opening 5, and a box-shaped space 13 is formed at the lower end of the sinking skeleton 12, and the jack 15 is fixed in the space 13. It is set by the metal fitting 16.

Explaining the caisson method having the above structure with reference to FIG. 7, first, as shown in FIG. 7A, the outer guide plate 6 and the lower rib 9 below the pressure plate 7 of the blade 5 are embedded in the ground. As shown in FIG. 5, the blade openings 5 are fixed with bolts to form a rectangular blade opening. Next, as shown in FIG. 2B, the sinking skeleton body 12 is constructed and a box-shaped space 13 is formed at the lower end thereof, and then the jack 15 is set in the space 13 as shown in FIG. Then, the fixing bolts between the blocks A and B, I'and between the blocks A ', I and B'of the blade tip 5 shown in FIG. 5 are removed, and as shown in FIG. After excavating the lower surface, as shown in FIG. 5 (e), pressure is applied to the jacks 15 in the blocks A and A'and the blade edge 5 is pushed in at the same time. Then, after excavating the lower surface in the blocks F and F'in a similar manner, pressure is applied to the jack 15 to push the blade edge 5 in the blocks B and B ', E and E'in this order, that is, at symmetrical positions. It is to push in the blocks at the same time. Then, when the pressing of all the blade openings is completed, as shown in FIG. 5 (f), the jack 15 is contracted to sink the sinking skeleton 12, and the following steps (d) to (f) are repeated to repeat the sinking skeleton 1.
It sinks 2.

However, in the above-mentioned construction method, in the ground having a high N value, a method of forming a hollow under the cutting edge or injecting muddy water around the caisson is generally used to promote the subsidence. With these methods, it is extremely difficult to cause subsidence at a scheduled time or to end subsidence by a predetermined amount.

An object of the present invention is to further improve the caisson method by dividing the blade opening, and it is an object of the present invention to facilitate the control of caisson deposition even in the ground having a high N value.

[0010]

To this end, the caisson dipping method by dividing the blade opening portion according to the present invention has a plurality of divided blade openings 5 and an installation fixed via the plurality of blade openings 5 and jacks 15. A skeleton 12 and a vibrator 30 which is arranged so as to be able to move in and out of a space 27 formed in the sinking skeleton 12 and vibrates the blade 5 are provided, and the plurality of blades 5 are divided into several sets of blocks. When excavating the blade mouth portion and press-fitting the blade mouth in order for each block, the sinking skeleton is caused to sink while vibrating the blade mouth. In particular,
Two guide rails 32 are fixed to the submerged frame 12, and two branch rails 32 are provided below the guide rail 32.
It has a structure in which a is inclined and enters the inside of the space 27.
The branch rail 32a of the book has a structure that merges with the vertical rail 32b. On the other hand, the vibrator 30 is hung by the lifting wire 35, and the vibrator 30 is provided with two rails on both sides.
Individual pulleys 36 are attached, and the pulleys 36 are configured to slide in the grooves of the guide rail 32.

[0011]

In the present invention, as shown in FIG.
After removing the fixing bolts between the blocks A and B, I'and A'and I, B ', the lower surface of the blocks A and A'is excavated, pressure is applied to the jacks 15 in the blocks A and A', and the cutting edge is cut. 5 at the same time, then block F
Similarly, at F and F ', press the blade edge, and then block B
And B ', E and E'in that order, that is, two blocks at symmetrical positions are pushed in at the same time, and when pushing of all the blade ends is completed, the jack 15 is contracted to sink the sinking skeleton 12, and the following steps are repeated. The sinking skeleton body 12 is caused to sink. In addition, when pushing in the blade 5, the vibrator 3
By vibrating the blade opening 5 by 0, the frictional force with the natural ground is reduced and the penetration of the blade opening 5 and the sinking of the sinking skeleton 12 are easily performed.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a front view showing an embodiment of a blade end portion in a caisson sinking method by dividing the blade end portion of the present invention, and FIG.
1 is a sectional view taken along the line AA of FIG.
4 is a sectional view taken along the line BB in the direction of the arrow, and FIG. 4 is a view for explaining the operation of the present invention, and is a sectional view taken along the line C-C of FIG.

The present invention also employs a structure in which the blocks of the plurality of divided blade openings 5 described in FIG. 5 are connected in a rectangular shape. The adjacent blades 5 are movable in the vertical direction along the blade guide 19. The blade opening 5 is formed in a triangular cross section by the vertical press-fitting plate 21, the inclined press-fitting plate 22, and the horizontal support plate 23, and a large number of them are provided between the vertical press-fitting plate 21, the inclined press-fitting plate 22 and the horizontal support plate 23. The reinforcing rib 25 is fixed. The upper part of the inclined press-fitting plate 22 constitutes a vertical part 22a (FIG. 3), and the vibration applying plate 26 is provided between the vertical part 22a and the vertical press-fitting plate 21 at the central part of the horizontal support plate 23.
(Fig. 1) is fixed. The sinking skeleton 12 is constructed between the vertical press-fitting plate 21 of the blade opening 5 and the vertical portion 22a of the inclined press-fitting plate 22. At this time, a space 27 for a vibrator is formed in the center of the lower end of the sinking skeleton 12. Jacking spaces 29 are formed on both sides of the lower end of the sunk body 12. Then, the vibrator 30 is set in the vibrator space 27, and the press-fit jack 15 is set in the jack space 29 between the sinking frame 12 and the horizontal support plate 23. The arrangement structure of the vibrator 30 will be described with reference to FIGS. 1 and 4. In the sinking frame 12,
Two guide rails 32 are fixed in the vertical direction by a fixture 33, and two guide rails 32a are inclined below the guide rail 32 to enter the inside of the vibrator space 27, The two branch rails 32a have a structure that merges with the vertical rail 32b. On the other hand, the vibrator 30 is suspended by the lifting wire 35, and two pulleys 36 are attached to both sides of the vibrator 30, and the pulleys 36 slide in the groove of the guide rail 32. Has been done. Therefore, when the lifting wire 35 is loosened from the state of FIG. (A), the pulley 36 reaches the vertical rail 32b through the branch rail 32a, and the vibrator 3
Since the chuck portion 30a of 0 grabs the vibration applying plate 26,
Vibration can be applied to the blade 5 by the vibrator 30. At this time, since the two branch rails 32a have a structure that joins the vertical rails 32b, the chuck portion 30a of the vibrator 30 can reliably grasp the vibration imparting plate 26.

The caisson method constructed as described above is the same as that described with reference to FIG. 7, except that when the press-fitting jack 15 is extended and the blade end 5 is pushed in, the blade end 5 is vibrated by the vibrator 30. In addition, the frictional force with the natural ground is reduced to facilitate the penetration of the blade opening 5 and the sinking of the sinking skeleton 12. Therefore, it is particularly effective when the ground is highly viscous clay or compacted sandy soil.

[0015]

As described above, according to the present invention, by dividing the caisson blade opening portion and connecting the blade opening portion and the body with a jack, the weight of the body, which is a sinking promoting force, can be part of the blade. It is possible to concentrate on the mouth, and it is possible to break it down while controlling the ultimate support state of the cutting edge ground, which is a deterrent to the caisson's sinking, and it is possible to easily control the caisson's sinking. Then, at that time, by vibrating the divided blade mouth portions at a predetermined time, it is possible to cut the frictional force between the body and the surrounding ground, which is another restraining force of the caisson, in a controlled state. The caisson can be controlled more easily even on high-value ground.

Further, since the divided blade mouth portions are vibrated, the problem that the portion where the muddy water does not rotate does not sink like the conventional method using muddy water is solved, and in comparison with the case where the entire body is vibrated. It can be vibrated with extremely small energy. Further, since partial subsidence of the skeleton can be generated, it becomes easy to prevent unequal subsidence of the skeleton.

[Brief description of drawings]

FIG. 1 is a front view showing an example of a blade end portion in a caisson digging method by dividing the blade end portion according to the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG. 1 as seen from the direction of the arrow.

FIG. 3 is a sectional view taken along the line BB of FIG. 1 and viewed from the direction of the arrow.

FIG. 4 is a view for explaining the operation of the present invention, which is a cross-sectional view taken along the line CC of FIG.

FIG. 5 is a plan view showing a blade opening division structure to which the present invention is applied.

FIG. 6 is a cross-sectional view showing the structure of a connecting portion between the blade opening portion and the sinking skeleton in FIG.

FIG. 7 is a diagram for explaining a caisson digging method by dividing the blade opening.

FIG. 8 is a sectional view showing a conventional caisson digging method.

[Explanation of symbols]

5 ... Blade mouth, 12 ... Sinking frame, 15 ... Press-fit jack, 19
... Blade edge guide 21 ... Vertical press-fitting plate, 22 ... Inclined press-fitting plate, 22a ... Vertical part, 23 ... Horizontal support plate 25 ... Reinforcing ribs, 26 ... Vibration imparting plate, 27 ... Vibrator space 29 ... Jack space, 30 ... Vibrator, 30a ... Chuck part 32 ... Guide rail, 32a ... Branch rail, 32b ... Vertical rail 33 ... Fixing device, 35 ... Lifting wire, 36 ... Pulley.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Yozo Abe, 2-16-1, Kyobashi, Chuo-ku, Tokyo Shimizu Construction Co., Ltd. (72) Ino Shiro, Uno 2-1-1, Kyobashi, Chuo-ku, Tokyo Shimizu Construction Co., Ltd.

Claims (2)

[Claims] 1. A plurality of divided blade openings, a submerged skeleton body fixed to the plurality of blade openings via a jack, and a blade opening arranged in a space formed in the submerged skeleton body so as to be accessible. And a vibrator for vibrating the plurality of blades, and dividing the plurality of blades into several sets of blocks, while excavating the blades and pressing the blades in order for each block, while vibrating the blades. A caisson sinking method by dividing the blade opening, which is characterized by sinking the sinking skeleton. 2. The two guide rails are fixed to the sinking skeleton, and two branch rails are inclined below the guide rail to enter the inside of the space. The rail has a structure that joins the vertical rail, while the vibrator is suspended by a lifting wire, and pulleys are attached to both sides of the vibrator, and the pulleys slide in the groove of the guide rail. The caisson digging method according to claim 1, wherein the caisson portion is divided.