JPH0478769B2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a method for press-fitting a caisson that can be applied to large-scale earth retaining walls or foundation structures, and more specifically, a method for press-fitting each divided body configured in a split type. This invention relates to a method of press-fitting a caisson by applying a reaction force to adjacent divided bodies.

<Prior Art> Generally, a caisson is press-fitted using its own weight or the weight of a loaded load.

Furthermore, as a method for press-fitting a caisson without relying on a loaded load, there is a known method in which the caisson is press-fitted by obtaining a reaction force from a preceding anchor driven in before press-fitting the caisson.

<Problems to be Solved by the Present Invention> The conventional anchor press-fitting method described above has the following problems.

<B> In the case of the method that uses the weight of the load, the larger the caisson, the greater the load required, which is one of the reasons for the rise in construction costs.

<B> In the case of press-fitting using a leading anchor, as the press-fitting depth of the caisson increases, the area of frictional resistance with earth and sand increases, and a large reaction force is required.

Therefore, construction of the preceding anchor requires a great deal of expense and labor, and there is a limit to the reaction force that can be obtained from the preceding anchor.

<C> In either the loading press-in method or the advance anchor method, the entire blade of the caisson is press-fitted at once, which has a large impact on the surrounding ground.

<Objective of the present invention> The present invention was made in order to solve the above-mentioned problems, and an object of the present invention is to provide a method for press-fitting a caisson that does not require a large loading load or a leading anchor and can be press-fitted efficiently and economically. purpose.

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

<A> Press-fitting principle The present invention consists of a plurality of vertically divided caissons in the form of a cylinder, column, or wall, and press-fits each divided body by determining the press-fitting reaction force of each divided body into the adjacent divided body. In this method, a divided body is constructed and extended on top of the divided body, and the caisson of the design dimensions is press-fitted to a predetermined depth by repeating the press-fitting work of each divided body and the extension work of each divided body.

<B> Caisson (Fig. 1) The caisson 1, which has a cylindrical completed shape, is divided vertically into a plurality of arc-shaped segments 2a, 2b, 2c.
...It becomes more.

In this embodiment, since the caisson 1 has a cylindrical shape with open upper and lower ends, each of the divided bodies 2a, 2b, 2c...
is formed in the shape of a circular arc.

The divided bodies 2a, 2b, 2c, etc. are engaged with each other through both sides, and the engagement structure may be a combination of a protrusion 21 and a groove 22 as in this embodiment, or an interlocking structure. A known engagement structure such as a locking pipe type or a nut clutch joint can be used.

<C> Press-fitting device FIG. 2 shows the press-fitting device 3 for the caisson 1.

This press-fitting device 3 has a cross girder 31 and a cross girder 31.
It consists of a reaction force receiving material 32 hanging from the outermost lower part of the cross section 32, and a plurality of sets of press-fit cylinders 33 hanging from the cross girder 31 inside the reaction force receiving materials 32, 32.

The cross girder 31 includes at least the divided bodies 2a, 2b,
2c... shall be long enough to straddle each one individually.

The reaction force receiving material 32 is made of a material with high tensile strength, and its lower end is configured to be detachable from the upper part of the divided bodies 2a, 2b, 2c, . . . .

The press-fitting cylinder 33 does not need to be large enough to press-fit the entire caisson 1 at once; it is sufficient to be small enough to press-fit each of the divided bodies 2a, 2b, 2c, . . . .

The shape of the cross beam 31 and the specific locations of the reaction force receiving material 32 and the press-fit cylinder 33 are determined depending on the cross-sectional shape of the caisson 1.

<Press-fitting method> Next, the method of press-fitting the caisson will be explained.

<A> Press-fitting the divided body (Fig. 2) When press-fitting, for example, the divided body 2b constituting the caisson 1, first press-fit the divided body 2 adjacent to the divided body 2b.
Reaction force receiving materials 32 and 32 are connected to a and 2c to ensure a source of reaction force for the press-fitting device 3.

Then, the divided body 2b is press-fitted by one stroke of the press-fitting cylinder 33.

Since the press-fit resistance area of the divided body 2b is half the resistance area of the adjacent divided bodies 2a and 2c, when the press-fit cylinder 33 is extended, the divided body 2
A and 2c will never escape.

Moreover, the divided body 2b to be press-fitted is the divided body 2b on both sides.
Since it is guided by a and 2c, there is no need to worry about the press-fitting direction being bent.

<B> Moving the press-fitting device After completing one stroke of press-fitting the divided body 2b,
Remove the press-fitting device 3, and then remove the divided body 2d to be press-fitted.
Move directly above.

In this embodiment, a case will be described in which the divided bodies 2a, 2b, 2c... are press-fitted every other one.
The press-fitting device 3 may be moved by skipping more than one step.

<C> Extension of the divided body (Fig. 3) An extension part 2b' having a height of one span is added to the upper part of the divided body 2b.

Extension part 2b' will be concreted on site.
It can be constructed as an RC structure, or it can be constructed by placing a prefabricated block body on top.

The press-fitting work of each divided body 2a, 2b, 2c, etc. explained above, and the divided bodies 2a, 2b, 2 after press-fitting.
c. Repeat the extension work to press fit to the specified depth.

<d> Relationship between depth and reaction force Each divided body 2a, 2b, 2c increases in proportion to the press-fitting depth.
Even if the press-fit resistance increases, the press-fit resistance generated in one divided body will never exceed the frictional resistance force between the two divided bodies on both sides that seek reaction force with the ground.

Therefore, unlike conventional leading anchors, there is no limit to the reaction force, and a reaction force corresponding to the press-fitting depth can always be obtained.

<E> Integration of caisson (Fig. 4) Each segment 2a, 2b, 2c pressed into the ground...
A PC steel wire 4 is placed between them, and prestress is introduced to tighten them.

In addition, bolt connection may be employed as a means for integrating the divided bodies 2a, 2b, 2c, . . . .

<F> Excavation Excavate the inside of the completed caisson 1 to complete the press-fitting of the caisson 1.

<Other Examples> In addition to the cylindrical caisson 1, a columnar body or a wall-shaped body can also be press-fitted in the same process.

<Effects of the Present Invention> Since the present invention is as described above, the following effects can be obtained.

<A> In the conventional press-fitting method of obtaining a reaction force into the ground, it was difficult to obtain a large reaction force because the reaction force required for press-fitting the caisson increases in proportion to the depth of the caisson.

Since the present invention is a method of obtaining reaction forces in the divided bodies other than those scheduled for press-fitting, it is possible to always obtain reaction forces corresponding to the press-fitting depth of the caisson.

<B> Since the caisson segments are individually press-fitted, a large pressing force is not required.

Moreover, it has less impact on the surrounding ground.

<C> Since the press-fitting work of each divided body and the extension work of each divided body can be performed continuously in parallel, construction can be carried out efficiently.

<D> Since the reaction force of the two divided bodies is used, the resistance area against the ground is doubled.

<E> Since the press-fitting device is removably connected to the upper part of the divided body, the press-fitting operation becomes easy.

[Brief explanation of the drawing]

Fig. 1: An overall perspective view of the caisson according to the present invention when press-fitting, Fig. 2: An explanatory view when the divided body is press-fitted, Fig. 3: An explanatory view when the divided body is extended, Fig. 4:
An explanatory diagram when the divided bodies are combined.

Claims (1)

[Claims] 1. A method for press-fitting a caisson vertically divided into a plurality of divided bodies, comprising the steps of removably connecting a press-fitting device to the upper part of the divided bodies on both sides so as to straddle the divided bodies to be press-fitted. , A step of press-fitting the divided body to be press-fitted by obtaining a reaction force from the divided bodies on both sides by the press-fitting device, and a step of adding and extending the upper part of the divided body after press-fitting are performed in parallel. A caisson press-fitting method characterized by: