JPH07100939B2 - Cason dipping method by dividing the blade opening - Google Patents

Description

Description: [Field of Industrial Application] The present invention relates to a caisson laying method adopted for an underground skeleton foundation structure in civil engineering and construction.

[Conventional technology]

As an example of the conventional caisson digging method, an example of an open caisson will be described with reference to FIGS. 7 and 8. FIG. 7 shows a ground anchor press-fitting method in which the ground anchor 1 is installed in advance in the ground and the ground anchor is installed. 1 is passed through the sinking skeleton body 2 and fixed by a jack 3, and the jack 3 is extended to sink the sinking skeleton body 2 by using the earth anchor 1 as a reaction force. Further, FIG. 8 shows a loading press-fitting method, in which the support piles 4 are preliminarily constructed in the ground, and the support piles 4 are
The jack 3 is disposed between the sinking skeleton 2 and the sinking skeleton 2, and by extending the jack 3, the sinking skeleton 2 is sunk by using the support pile 4 as a reaction force.

[Problems to be solved by the invention]

Conventionally, especially with the open caisson method, it is difficult to excavate the tip of the blade edge, and as can be seen from the difference in the peripheral frictional force between the open caisson and the pneumatic caisson,
It was not possible to distinguish between the tip support force and the subsidence resistance force due to the frictional force on the peripheral surface, and it was determined empirically. Since the amount of 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 slightly depending on the excavation method. In addition, if unequal settlement of caisson occurs, there is a problem that heaving that causes soil to enter the root cutting surface from the outside and raises the bottom surface, and boiling that causes soil particles to move due to head pressure. are 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 loading press-fitting method, when constructing deep ground, temporary construction work becomes large scale and Since there is no basis for bearing capacity for increased load when constructing the frame, and settlement control mainly depends on the intuition of field experience, it is difficult to control settlement such as sudden settlement, and safety measures and construction process aspects Had a problem.

The present invention solves the above problem, and an object of the present invention is to provide a caisson laying method capable of reliably controlling the settlement of the caisson and preventing the heaving or the boiling caused by the unequal settlement.

[Means for solving problems]

Therefore, the caisson digging method by dividing the blade opening portion of the present invention includes a plurality of divided blade openings, a pressure plate horizontally projecting inside the blade opening, and a pressure plate and a jack. A fixed sinking skeleton is provided, the plurality of blade openings are divided into a number of sets of blocks, and the blade openings are sequentially excavated for each set of blocks at symmetrical positions of the blocks, and then the blade openings are press-fitted with a jack, When press-fitting, the load of the sinking skeleton is characterized by supporting the ground with the pressure plate of the blade opening other than the block at the time of press-fitting, and compressing the jacks after press-fitting all the blade openings to sink the sinking skeleton. Is.

[Action]

In the present invention, for example, as shown in FIG. 1, after fixing bolts between the blocks A and B, I ′ and A ′ and I and B ′ of the cutting edge 10 are excavated, the lower surfaces of the blocks A and A ′ are excavated. , Blocks A and A'press the blades 20 at the same time by applying pressure to the jacks 20, and then blocks F and F'in the same manner, and then blocks B and B ', E and E'in that order. That is, when two blocks at symmetrical positions are pushed in at the same time and pushing of all the blade openings is completed, the jack 20 is contracted to sink the sinking skeleton 18, and thereafter, this step is repeated to sink the sinking skeleton 18.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. First
FIG. 1 is a plan view showing an embodiment of a blade opening portion in a caisson sinking method by dividing the blade opening portion of the present invention, FIG. 2 is a perspective view showing a portion of the blade opening portion of FIG. 1, and FIG. The side view which shows the structure of the connection part of the blade edge part and the sinking skeleton in the caisson sinking construction method by the blade edge part division | segmentation of the invention, FIG. 4 is the front view, 5th.
FIG. 6 is a plan view thereof, and FIG. 6 is a view for explaining one embodiment of a caisson digging method by dividing a blade opening according to the present invention.
In the figure, 10 is a blade edge, 11 is an outer guide plate, 12 is a pressure plate, 13 is a lower rib, 14 is an upper rib, 15 is an inner guide plate, 16 is a gap, 17 is a bolt hole for coupling, and 18 is a sinking frame. , 19 is a space, 20 is a jack, 21 is a fixture, and 22 is a bolt.

FIG. 1 shows a state in which blocks of a plurality of blades 10 are connected and fixed in a rectangular shape. As shown in FIG. 2, the blade 10 has a pressure plate 12 horizontally projected and attached to the inside of a vertical outer guide plate 11 so that the lower surface of the pressure plate 12 and the outer guide plate 12 can be fixed.
A plurality of lower ribs 13 are fixed over 11 and pressure plate 12
A plurality of upper ribs 14 and an inner guide plate 15 are attached and fixed to the upper surface of the. Further, a gap 16 is formed on the left and right of the inner guide plate 15, and a coupling bolt hole 17 is provided on the upper ribs 14 on the left and right ends.

Referring to FIGS. 3, 4, and 5, the structure of the connecting portion between the blade opening portion and the sinking skeleton will be described.
It is constructed between the outer guide plate 11 and the inner guide plate 15, and a box-shaped space 19 is formed at the lower end of the sinking skeleton 18, and the jack 20 is set in the space 19 and the sinking skeleton is set by the fixing metal fitting 21. It is fixed to 18, and the pressure plate 12 is fixed by bolts 22.
It is fixed to.

Next, referring to FIG. 6, one embodiment of the caisson staking method by dividing the blade mouth portion of the present invention will be described. First, as shown in FIG. 6A, the outer guide plate 11 below the pressure plate 12 of the blade mouth 10 is shown. Then, the lower rib 13 is embedded in the ground, and the blade openings 10 are fixed by bolts through the connecting bolt holes 17 to form a rectangular blade opening portion as shown in FIG. Next, as shown in (b) figure, after constructing the sinking skeleton 18 and forming a box-like space 19 at the lower end thereof, as shown in (c) figure, the jack 20 is placed in the space 19.
Set.

Next, the fixing bolts between the blocks A and B, I'and A'and I, B'of the blade tip 10 shown in FIG. 1 are removed, and as shown in FIG. After digging, the jacks 20 in the blocks A and A ′ are pressed to simultaneously push in the cutting edge 10 as shown in FIG. Next, after similarly excavating the lower surface in the blocks F and F ', pressure is applied to the jack 20 to push the blade opening 10 in the order of blocks B and B', E and E ', that is, at two symmetrical positions. The block is pushed in at the same time. And when all the blades have been pushed in,
(F) As shown in FIG.
And the following steps (d) to (f) are repeated to sink the sinking skeleton 18.

When pressing the blade edge, the press-fitting is divided into several blocks, so each block is press-fitted according to the condition of the supporting ground so as not to cause uneven settlement of the caisson,
The caisson load is designed so that it can be supported by the ground with the pressure plate of the blade opening other than the block at the time of press fitting, as shown in FIGS. 6 (e) and 6 (f). Also, the pressure plate of the blade can be removed or the supporting area can be adjusted.

The present invention is not limited to the above embodiment, and various modifications can be made.

For example, in the above embodiment, two blocks at symmetrical positions are pushed in at the same time, but a plurality of places such as four places may be pushed in.

〔The invention's effect〕

As described above, according to the present invention, since the pressure plate is provided so as to project in the horizontal direction inside the blade opening, when pressing the blade opening of the divided block, the blade other than the block at the time of press fitting By adjusting the support area of the pressure plate that projects horizontally inside the mouth, the load of the sinking skeleton is supported according to the bearing force of the ground, and the sinking skeleton is sunk so as not to settle unevenly. be able to.

Also, since the pressure plate supports the load of the sinking skeleton on the ground, by adjusting the support area of the pressure plate according to the supporting force of the soft ground, it is possible to prevent heaving, boiling, etc. during press fitting. After press-fitting, it becomes a support plate that can support the caisson load and can be safely installed even on soft ground.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of a blade opening portion in a caisson sinking method by dividing the blade opening portion according to the present invention, FIG. 2 is a perspective view showing a portion of the blade opening portion of FIG. 1, and FIG. FIG. 4 is a side view showing the structure of the connecting portion between the blade mouth portion and the sinking skeleton in the caisson sinking method by dividing the blade mouth portion according to the present invention, and FIG.
FIG. 5 is a plan view thereof, FIG. 6 is a view for explaining one embodiment of a caisson staking method by dividing the blade opening portion according to the present invention, and FIGS. 7 and 8 are sectional views showing a conventional caisson staking method. It is a figure. 10 …… Blade, 11 …… Outer guide plate, 12 …… Pressure plate, 13 ……
Lower rib, 14 …… Upper rib, 15 …… Inner guide plate, 16 …… Gap, 17 …… Coupling bolt hole, 18 …… Sinking frame, 19 …… Space, 20 …… Jack, 21 …… Fixing bracket , 22 …… Bolt.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Koji Kondo 2-16-1, Kyobashi, Chuo-ku, Tokyo Shimizu Construction Co., Ltd. (72) Inventor Yoshio Kojima 2-16-1, Kyobashi, Chuo-ku, Tokyo Shimizu Construction company (72) Inventor Yoko Morii 2-16-1, Kyobashi, Chuo-ku, Tokyo Shimizu construction company (56) References JP-A-61-142231 (JP, A)

Claims (1)

[Claims] 1. A plurality of divided blade openings, a pressure plate provided in the blade opening so as to project in the horizontal direction, and a sinking frame fixed to the pressure plate via a jack. After dividing the blade mouth into a large number of blocks and excavating the blade mouth portion for each group of blocks at symmetrical positions of the blocks in sequence, press the blade mouth with a jack, and when press-fitting, the load of the sinking skeleton is A caisson dipping method by dividing the blade opening by supporting the ground with the pressure plate of the blade opening other than the block at the time, compressing the jacks after all the blade openings are pressed, and sinking the sinking skeleton.