JP2815470B2 - Buoyancy-adjustable movable support construction method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a buoyancy-adjustable movable shoring method for constructing a concrete floating structure on a pile head projecting above the water.

[Conventional technology]

When constructing a floating structure such as an offshore platform or a pier on the head of a pile group that protrudes from the water, in addition to the formwork, a shoring for supporting the formwork is required.

At this time, since the water surface does not directly support the surface, conventionally, a bracket is attached to the pile to support the formwork, or the work boat is positioned directly below the construction site and then mounted on the work boat. Use the upper surface of the equipment to assemble the shoring and formwork, construct the floating structure at a position higher than the head of the pile, and then lower the constructed floating structure and install it on the pile head Construction methods are generally known.

[Problems to be Solved by the Invention] However, the conventional construction method as described above has the following problems. That is, (a) Assembling and dismantling are not easy unless the support is small. However, since small supports cannot support heavy objects, beams, slabs, and the like cannot be integrally cast.

(B) Where the spacing between piles changes, there is no form of support that can be used anywhere.

(C) Since the removal of the formwork must depend on the offshore work (ship work), it requires a great amount of work time and labor, and there is a risk that the worker may fall down, which is very dangerous.

(D) Since the work of assembling, disassembling and moving the formwork and the shoring work at sea requires a great deal of work, the construction efficiency is extremely low.

(E) In this method, the work is performed at a low tide when the waves are calm, so that the work is greatly affected by the weather conditions, and the work time is short and limited.

(F) Since the pile surface is subjected to corrosion treatment against seawater or the like, the pile cannot be welded or the like, so that the pile itself cannot be supported (bracket type).

(G) In order to prevent damage due to waves, it is necessary to reduce the number of members.
Contradict.

The present invention has been made in view of the above-described conventional problems, and has as its object to solve the above-mentioned problems by using a buoyancy-adjustable movable supporter.

[Means for solving the problem]

In order to achieve the above object, the present invention, in the construction of a floating concrete structure having a different pile interval, a large shoring capable of adjusting the buoyancy by taking in and out of water, levitating and towing to a predetermined position between the piles, After being lifted to a predetermined height and fixed to the pile head suspension with a hanging steel rod, a small support and a ladder-like support are attached on this large support, and a form receiving support is assembled. After the prescribed curing period has elapsed, the shoring is disassembled and lowered to the surface of the water, and the buoyancy of levitation and towing to the next erection location using buoyancy It is a construction method using adjustable movable supports.

[Action]

The present invention is configured as described above, and large supports can be transported using buoyancy, so that they can be made larger in size than land transportation, and can be installed even in places where the spacing between piles is small for floating towing. It is possible. In addition, since the large-sized shoring lifted to a predetermined height by a crane or the like is fixed to the pile head hanging metal by a hanging steel rod, the surface of the anticorrosion-treated pile is not damaged.

When the large supports thus lifted and fixed are used as vertical members, small supports made of, for example, H-section steel are fixed as horizontal members on these vertical members, and a ladder-like support is further mounted on the small supports. By attaching the work, it is possible to assemble the form receiving support work according to the required shape. Next, a pre-manufactured formwork is placed and fixed on this support, and concrete is cast, whereby a concrete structure integrated with the pile is constructed.

As described above, since the number of combined members is small and firm, safety against external forces such as waves and strong winds until concrete hardens is high. Further, when dismantling the formwork, each of the supports can be lowered to the surface of the water in a state where the supports are partially assembled, and can be disposed by surfacing and towing to the next erection location using buoyancy. According to the above-described construction method, each work of assembling, disassembling, and moving the formwork and the shoring work does not require much labor as in the related art, and the danger of the work can be greatly reduced.

〔Example〕

Hereinafter, the present invention will be described with reference to the drawings. First to eighth
The figure is a diagram for explaining an embodiment of the present invention.

FIG. 1 is a perspective view showing the concept of a construction method using a buoyancy-adjustable movable support according to an embodiment. The procedure of this method is performed as schematically shown in FIG.

FIG. 1 illustrates a supporting structure which is a structural feature of the present invention. In the figure, the entire formwork support is
It consists of Shoring A and Shoring B. Shoring A is a steel pipe machined and manufactured on land.
And the small shoring 12 that connects them and this small shoring
A ladder-like member formed by a vertical member 21 and a horizontal member 22 is mounted on the structure 12. At this time, the large shoring 11 adjusts the buoyancy by taking in and out the water in consideration of the overall balance, and adjusts the posture as needed. The large support 11 is provided with a suspending band 11a at a required position for lifting as described later.

The shoring B forms a ladder-like member by combining the vertical members 31 and the horizontal members 32 and connects the large shoring 11.

A girder bottom form plate 13 made of a stainless steel plate or the like for receiving the form is provided on the upper surfaces of the supports A and B.

Then mold C after concrete curing, has become more C _1, C _2, C _3, slab form can 4 divided as C ₄ C _a and the medium cutting die frame portion C _b to allow demolding . That is, slab formwork
C _a is composed of fifth Tatezai 41 as shown in FIG, crosspiece 42, diagonal member 43, the molding surface 44. The concrete weight is supported by the supports A and B from the forming surface 44 via vertical members, horizontal members, diagonal members and the like.
Dismantling the mold C, 4 cutting die frame portion C _b in for splitting Tatezai
45, cross member 46, the molding surface 47, consist of a fixed bracket 48, fixed to the slab form C _a is carried out in the clip and mounting brackets 48.

Next, the method of constructing an underwater structure according to the present invention will be described step by step. First, as shown in FIG. 4, a pile head suspension metal fitting 50 is attached to a predetermined position of a structural member 60 provided on the pile head.
Next, as shown in Fig. 8, a large shoring made on land
11 is towed up and transported between piles at the site. Other members are transported by barges. When the large support 11 is placed at a predetermined position between the piles, the shoring is changed from a tugboat to a crane on the structural member 60 (the same figure).
Fixed to In addition, the small shoring 12, the shoring B, etc. are fixed to the large shoring 11 as described above, and the erection of the form receiving shoring is completed (the same figure). Next, the formwork C assembled on land is transported by a barge, suspended by a crane on the structural member 60, fixed to the supports A and B, and the erection of the formwork is completed (FIG. 5). Next, rebar is assembled in the assembled shoring and formwork, concrete is poured, and a floating structure is constructed. The weight of the floating structure is applied to the hanging hardware 50, the structural member 60, and the stakes 1 and 2 by the hanging steel rods 51.

Next, after a lapse of a predetermined curing period, the mold is removed and dismantled as follows, generally following the reverse process of the erection. First, Shoring A, B
Is temporarily suspended from the suspension point of the form C. The suspended steel rod 51 of the large-sized support 11 is cut (FIGS. 8 and 6), and is gently suspended in the water while adjusting left and right movements by the tune blocks at both ends. At this time, if the buoyancy of one of the large supports 11 is increased and the buoyancy of the other is decreased, the posture (a) is changed from (a) to (b) and the posture (a) is changed from (b) as shown in FIG.
Adjust from (b) to (c) and tow to the next erection site in a posture convenient for withdrawal. As shown in FIG. 7, the small shoring and the shoring B are dropped on the water in the same manner as described above,
Put it on 70 and tow to the next erection site.

Further, the mold C, as shown in Figure 8, allowed dropping medium trimming die frame portion C _b by tapping with hardware such as from slab openings,
4 divided slab C ₁ -C ₄ are lowered respectively by multiplying the rope I bolt, carrying put the floater.

FIG. 2 shows an embodiment of the form support shoring, and FIG. 3 shows an arrangement of the form erection erected on the support of FIG.
In the drawings, X-1 to X-5 and Z-2 to Z-5 are reference lines for design, construction, etc., and the dimensional figures are those of the embodiment.

By repeating the above steps, the floating structures are sequentially constructed for each predetermined block unit (FIGS. 2 and 3).

〔The invention's effect〕

As described above, according to the present invention, many effects as described below can be obtained. That is, (1) Beams and slab concrete can be integrally cast and a high-quality floating structure can be constructed.

(2) Large supports can be transported using buoyancy, so they can be made larger than conventional land transport, and can be adjusted in position by buoyancy, so they can be applied to places with narrow pile spacing.

(3) Since it is assembled on land, it becomes a high-precision member, and the finishing accuracy of a floating structure is improved.

(4) Since there is no embedded metal such as a separator, corrosion, deterioration, and the like do not occur from that portion.

(5) Since the number of combined members is small and firm, safety against external forces such as waves and strong winds until concrete hardens is high.

(6) Since the combination members are simplified, the number of workers such as skilled workers is reduced, and at the same time, work on water is reduced, and work safety is improved.

[Brief description of the drawings]

FIG. 1 is a conceptual view of a construction method using a buoyancy-adjustable movable shoring according to the present invention, FIG. 2 is a plan view of an embodiment of the shoring, and FIG. 3 is an arrangement of a formwork erected on the shoring in FIG. FIG. 4 is a plan view, FIG. 4 is a mounting view of the shoring A, B by the embodiment method, FIG. 5 is a view showing a state in which concrete is cast after the formwork is mounted, and FIG. FIG. 7 is a view showing the disassembly of the shoring B, and FIG. 8 is an explanatory view showing the method of the present invention in the order of. 1,2 …… pile, 11 …… large shoring, 12 …… small shoring, 50
... Pile head hanging hardware, 51 ... Hanging steel bars, A, B ... Formwork support, C ... Formwork.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-1-198914 (JP, A) JP-A-63-156108 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) E02B 17/00-17/08

Claims (1)

(57) [Claims] In the construction of a floating concrete structure having different pile intervals, a large shoring capable of adjusting buoyancy by taking in and out of water is floated and towed to a predetermined position between the piles, and the large shoring is lifted to a predetermined height. After fixing to the pile head suspension with the hanging steel rod, the small support and the ladder-like support are mounted on this large support, and the form receiving support is assembled. Thereafter, the form receiving is supported on the form receiving support. The buoyancy adjustment is characterized in that concrete is fixed and erected, and after a predetermined curing period has elapsed, each of the supports is disassembled and lowered to the surface of the water, and buoyancy is used to surfacing and towing to the next erection site. Construction method with movable support.