JP2630994B2 - Construction method of quay using caisson - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field The present invention relates to a method of constructing a quay using a caisson in a harbor or the like where a crane, a radar, and the like are installed.

(B) Background Art Recently, the construction of port structures such as container piers is expanding offshore, and in many cases, caisson is installed on mounds constructed under bad conditions such as deep water and soft ground. Therefore, in the case of soft ground, environmental problems associated with construction and economic problems such as ground improvement have become major issues.

Also, especially when constructing large gravity-type structures on soft ground at deep water depth, the mound subsidence and uneven settlement due to consolidation of the foundation ground will cause inconsistency in the height of the top of It may have adverse effects such as getting in and out.

Moreover, in order to construct a gravity-type structure capable of solving these problems, a great deal of cost such as large-scale ground improvement and a long construction period were required.

(C) DISCLOSURE OF THE INVENTION The present invention relates to a case where a caisson is used to build a large gravity-type structure in soft ground or deep water,
Upper structures that need to minimize displacement such as land subsidence,
For example, when installing cranes and radars, the conventional method requires that a large mound be built on the foundation ground with large-scale ground improvement as shown in Fig. 5, and then a caisson be installed. According to the present invention, the displacement amount of the crane foundation, the radar foundation, etc. is supported by the foundation pile inserted into the caisson through hole described later so that the displacement amount can be kept within the allowable range. Instead, the mound can be made small, and it is possible to construct a slim structure as a whole.

Since the upper structure of the caisson according to the present invention has a different supporting mechanism from that of the caisson, the foundation of a large heavy structure such as a crane or a radar is located at a position where the caisson mounted on a small mound is structurally congested. Therefore, even if a caisson is displaced, the upper structure is not affected even if the caisson is displaced.

Therefore, according to the present invention, it is possible to provide a method that is technically and economically excellent without requiring a long period of time for ground improvement and mound construction.

Hereinafter, as an embodiment of the method of the present invention, a case of building a crane foundation will be described with reference to the drawings.

(D) Embodiment First, as shown in FIGS. 2 and 3, when the caisson 1 is manufactured, a plurality of through holes 4 through which a foundation pile 7 described later can be inserted in advance at a predetermined position of the bottom plate 3 and an upper surface of the caisson 1 communicating therewith are formed. A guide tube 2 having a maximum length is provided.

Then, the foundation pile 7 is driven into the underground foundation ground 5 at the position where the crane foundation is to be constructed. The foundation piles 7 are erected at appropriate intervals corresponding to the through holes 4 (four in the figure) of the caisson.

After the foundation pile 7 is erected, a foundation rubble mound 6 made of embankment or rubble is formed to a predetermined size and height. In this case, the head of each foundation pile 7 projects above the upper surface of the mound 6.

Next, after leveling the upper surface of the mound 6, the caisson 1 is towed to a predetermined position on the mound 6 by the work boat 14, and each foundation pile 7 is placed in the guide pipe 2 provided in the caisson 1. The caisson 1 is settled so as to be inserted (FIGS. 4 (a) to 4 (b)).

As a result, when the caisson 1 is laid on the mound 6, the head of the foundation pile 7 projects into the caisson 1.

Therefore, a supporting pile 10 having the same diameter as the foundation pile 7 and having a length protruding above the caisson 1 is added to the end of the foundation pile 7 protruding into the caisson 1, and the crane foundation 11 serving as a structure on the caisson 1 is added. So that it can be installed continuously.

Thereafter, the caisson 1 is filled with a filling material such as sand or crushed stone, and a crane foundation 11 for installing a crane base 13 on the upper surface of the caisson 1 is formed. The support pile 10 is used as a foundation pile of the crane foundation 11 by being connected to the head end.

On the other hand, a split stone 9 is buried in the back of the caisson 1, and a landfill 8 is constructed behind it. Reference numeral 12 denotes a foundation pile for another crane foundation driven into the rear of the caisson 1.

(E) Effect of the Invention The present invention is configured as described above, and the load of the upper structure such as the crane on the caisson 1 is changed to the foundation pile 7 (and the support pile 10).
Since only the load of the caisson 1 is applied to the mound 6, the load on the mound can be reduced accordingly, and even if the caisson 1 is slightly displaced by sinking or the like, there is an effect that it is hardly affected.

Further, according to the present invention, since it is not necessary to increase the size of the mound, ground improvement costs can be reduced, and the construction period is shortened.

[Brief description of the drawings]

1 is an explanatory view of a harbor structure having a crane foundation constructed according to the present invention, FIG. 2 is a plan view of a caisson used in the present invention, FIG. 3 is a longitudinal sectional view of the caisson, and FIG. (A) to (b) are explanatory views showing one process of construction by the method of the present invention, and FIG. 5 is a sectional view of a harbor structure having a crane foundation constructed by a conventional method. Description of symbols 1 ... Caisson 2 ... Guide tube 3 ... Bottom plate 4 ... Through hole 5 ... Submarine base foundation 6 ... Mound 7 ... Foundation pile 8 ... Landfill earth and sand 9 ... Back Inclined stone 10 …… Support pile, 11… Crane foundation 12 …… Crane foundation pile, 13 …… Crane mount 14 …… Work boat, 15 …… Improved ground

Claims (1)

(57) [Claims] 1. A mound is constructed after a plurality of foundation piles are driven into a predetermined position on a seabed ground up to a supporting ground, and then a through hole is provided at a predetermined location of the bottom plate, through which the foundation pile can be inserted. A caisson provided with a guide pipe communicating with the hole up to the upper surface is settled so that the foundation pile protruding above the mound is inserted into the guide pipe through the caisson through hole and installed on the mound, Next, a supporting pile having a length protruding upward from the caisson is spliced at the head end of the foundation pile in the guide pipe, and the supporting pile supports a load of a superstructure such as a crane or a radar installed on the caisson. A method of constructing a quay using a caisson characterized by