JPH0372115A - Method for constructing foundation using workshop ship - Google Patents

Abstract

PURPOSE:To shorten the construction period of a foundation by annularly connecting a plurality of workshop ships to each other and annularly placing sheet piles in a sea area surrounded by the workshop ships, and connecting the workshop ships and the sheet piles together by means of support metal fittings, and constructing a foundation in a portion surrounded by the sheet piles. CONSTITUTION:A plurality of workshop ships 1 are connected together by connecting metal fittings 6 on a construction site sea surface while being arranged into the shape of a ring and seawater ballast is injected into the ballast tank of settled floating equipment 5 and are settled and seated on a temporary structure supporting ground 7. A series of annularly arranged sheet piles 13 are placed into an inside sea area surrounded by the workshop ships 1 and are connected together by sheet pile reinforcing metal fittings 14. After sea water is discharged from the inner part surrounded by the sheet piles 13, a foundation 16 for constructions is constructed. The sheet piles 13 are then removed and the workshop ships 1 are caused to float up and are also disconnected and separated from each other and removed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a foundation construction method using a work barge, which is applied, for example, to offshore bridge pier construction work.

(Prior Art) As for the foundation construction method conventionally applied to offshore bridge pier construction work, etc., the following method has been adopted in places where the support layer on the seabed exists at a relatively shallow water depth (approximately 10 rrL).

That is, as shown in Figures 3 and 4, steel pipe sheet piles or sheet piles made of steel sheet piles are driven in a ring around the pier a to be constructed, and the sheet piles are double hammered inside and outside to compensate for their strength. The inner sheet pile bl and the outer sheet pile b2 are each reinforced with sheet pile reinforcing metal fittings C, and the inner sheet pile bl and outer sheet pile b2 are connected with sheet pile connecting fittings d at appropriate locations. After constructing a work platform f supported by a large number of support piles e on the outside of the sheet pile b2 and draining and excavating the area surrounded by the inner sheet pile bl, the construction work of the pier a begins. It is carried out.

In the figure, g indicates the water surface, h indicates the ground supporting the temporary structure, and 1 indicates the ground supporting the permanent structure.

(Problem to be solved by the invention) However, in terms of strength, construction of water-stopping and earth-retaining sheet piles that requires double pouring both inside and outside, as well as construction of a workbench around the sheet piles, requires construction and removal. The construction work is large-scale and takes a long time, and the equipment cannot be reused due to corrosion or damage.Material costs are also high.Furthermore, noise prevention measures are required if there are residential areas nearby. There was a problem.

The present invention was proposed in view of the current situation, and
The purpose of the present invention is to compensate for the strength of a work platform that is used repeatedly by driving a circular single layer of sheet piles, and to shorten the construction period.

(Means for Solving the Problems) The structure of the present invention for achieving the above object will be explained using FIG. 1 and FIG. 2 corresponding to the embodiment. , a plurality of work barges (1) each having a sinking/floating facility (5) inside are connected in a ring shape and are lowered and seated in water, and water is stopped in the inner water area surrounded by the work barges (1). The water-stopping and earth-retaining sheet piles 03 are driven in a single ring shape, and the water-stopping and earth-retaining sheet piles α are connected to the work barge (], ) with supporting hardware αα, and then the water-stopping and earth-retaining sheet piles 0?? are surrounded. It is characterized by constructing a foundation for the structure inside.

(Function) The present invention uses the above-mentioned means to install a single ring-shaped water-stopping and earth-retaining sheet pile 0 in the inner surface area of the ring-shaped connection of the work barge (1) that is seated submerged in water. Since the water-stopping and earth-retaining sheet pile α3 and the work barge (1) are connected with supporting metal fittings (L-rips), the water-stopping and earth-retaining sheet pile 0 has good strength against wind and waves without having to double-cast it both inside and outside. However, the water stoppage and retaining sheet pile is 0.
Since the structure foundation Qf9 is constructed inside the structure surrounded by
13) and the work platform (2), the removal work becomes easy.

(Embodiment) An embodiment of the present invention will be described below based on FIGS. 1 and 2. (1) shows a work platform;
has a workbench (2) on the top surface, and has a ballast tuff (3) inside and sinking/floating equipment (5) for injecting and draining seawater Nolast (4) into the ballast tank (3). A plurality of work barges (1) are connected in a ring shape by connecting hardware (6) installed on each one above the construction sea level,
In this connected state, seawater ballast (4) is injected into the ballast tank (3) by the sinking and flotation equipment (5), so that the temporary structure is settled on the support ground (7).

If there is a slope or unevenness on the ground (7) that would be detrimental to the seating of the slipway (1), excavate the seabed in advance and apply sand (8) to make it possible for the platform (1) to sit on the ground. Button
. In addition, if the work barge (f) cannot obtain seabed pressing force due to the weight of its seawater ballast (4), the ground anchor (9), prestressed steel barge, prestressed steel guideway aυ, and head fixing hardware α Add an anchor consisting of.

Next, using a sheet pile driving machine on the work platform (2) of the work barge (1) that has been sunk and seated, sheet piles 0 are driven in a single layer in an annular manner into the inner water area surrounded by the work barge (1). 0 are connected with sheet pile reinforcing hardware a chrysanthemum, and the sheet pile reinforcing hardware 0 and work barge (1) are connected with sheet pile supporting hardware (L'5) to reinforce the driven sheet piles (13). Then, the work barge (1) is used to drain the seawater inside the interior surrounded by the sheet pile 0, excavate the water after draining, and construct the foundation α0 for the structure after the excavation.

After the construction was completed, the ring-shaped sheet pile 0 country was removed and the work barge (
1) uses the sinking and flotation equipment (5) to drain the seawater ballast (4) in the ballast tank (3), float the barge (1), and release the mutual connection between the barges (1). Separate and remove. The outline in the figure indicates the supporting ground for the permanent structure.

(Effects of the Invention) According to the present invention, a plurality of work platforms (1) each having a work platform (2) on the upper surface and a sinking/floating facility (5) inside are connected in a ring shape and placed underwater. The work barge (1) will be placed in a seated position, and a water stop and earth retaining sheet pile will be installed in the inner water area surrounded by the work barge (1).
After connecting the water stop and earth retaining sheet pile αJ and the work barge (1) with supporting metal fittings (I9), a foundation for the structure is installed inside the area surrounded by the water stop and earth retaining sheet pile a3. Since αQ is constructed, the water-stopping and earth-retaining sheet pile 0 is supported by the work barge (1) that surrounds it, making it possible to eliminate the conventional driving of the sheet pile 0 with a double structure inside and outside, and to replace the conventional work platform. By abolishing the construction of a It has the effect of reducing

[Brief explanation of drawings]

FIG. 1 is a plan view of an apparatus for carrying out the method of the present invention, FIG. 2 is a sectional view taken along the line A-A in FIG. 1, and FIG. 3 is a partially cutaway plan view of an apparatus for carrying out the conventional method. FIG. 4 is a sectional view taken along the line B--B in FIG. 3. (1)...Work platform (2)...Work platform (5)...Sinking and flotation equipment Q3I...Sheet pile 0
! 19...Support hardware αG...Structure foundation agent Patent attorney Shige Okamoto 1 extra person

Claims (1)

[Claims] A plurality of work platforms with upper surfaces as work platforms and internal sinking and flotation equipment are connected in a ring shape and are lowered and seated in water, and a water stop and earth retaining sheet pile is installed in the inner water area surrounded by the work platforms. The structure is characterized by constructing a foundation for a structure inside the water-stopping and earth-retaining sheet pile surrounded by the water-stopping and earth-retaining sheet pile after the water-stopping and earth-retaining sheet pile is connected to the work barge using supporting hardware. A foundation construction method using a work barge.