JPS6210338A - Fitting of timbering work for covered steel tubular pile - Google Patents

Abstract

PURPOSE:To permit superstructure and its load to be supported without damaging the corrosion-resistant function by a method in which a steel band welded with a bracket an fitted with a lining material for its inside is attached to a covered steel tubular pile, and form planels, etc., are supported by the bracket. CONSTITUTION:After a steel tubular pile 1 covered with an anticorrosive covering material 2 is driven, a steel bracket 9 is welded to the portion deprived to the covering material 12 of the pile 1, and a steel band 8 whose inside is bonded with an anticorrosive material having a great frictional coefficient, e.g., hard rubber, is clamped to the pile 1 by a clamping force 2-3 times load acting on the timbering work, for example. A formwork material 5 is then supporteds through a formward supporter 5 by fixing the band 8 by bolts 10 as the timbering work. The cutting-into the covering material and slackening- down of the band 8 can thus be prevented and the superstructure and various load can be effectively supported simply without damaging the original anticorrosive function.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a structure built on the sea, such as a port structure, and supported by steel pipe piles, particularly plastic-coated steel pipe piles, from below, such as by concrete pouring. This invention relates to a shoring installation method for coated steel pipe piles in the construction of structures that cannot be supported from the ground, such as those on land, when upper load support is required.

(Prior art) In general, in the construction of offshore structures, the construction of supports for attaching formwork etc. to steel pipe piles that are not coated with plastic is carried out in "Port/Airport Construction Methods (Part 1)" edited by Yoshibe Haraguchi (Showa 53).
-4-30) As described in Sankaido p. 394-396, the following method is taken.

(a) As shown in Figure 4, weld the support bracket to the steel pipe pile at the bottom of the pile.

φ) As shown in Fig. 5, all the horizontal members are attached to the head of the steel pipe pile, the hanging reinforcing bars are lowered from the horizontal members, and the shoring is suspended and supported by the hanging reinforcing bars.

That is, in FIG. 4, a bracket 7 is welded to a steel pipe pile 1 covered with an anti-corrosion coating material 2, and a formwork material 6 is attached via a formwork support material 5.
Figure 5 shows the entire structure supporting the steel pipe pile 1, with a horizontal beam 3 with hanging reinforcing bars 4 attached to the head of the steel pipe pile 1, and a formwork supporting material 5 attached to the lower end of the hanging reinforcing bar 4 being used to form the form. This shows the structure in which the frame members 6 are fully supported.

In the case of steel pipe piles coated with plastic, either method (b) is used, or the covering material is removed and construction is performed using method (a), and after the shoring is removed, the covering material is repaired at sea.

(Problem to be solved by the invention) In the case of method (b), after concrete is poured, the ends of the hanging reinforcing bars that protrude from the bottom of the concrete are cut off. Exposed parts must be carefully protected against corrosion.

With method (a), it is difficult to maintain the repair quality of the covering material at a high level on site, and the original anticorrosion function of the covering material may be significantly impaired at the repaired portion. Therefore, an object of the present invention is to provide a construction method for easily constructing shoring with sufficient supporting capacity (load-bearing capacity) without damaging the sheathing material or reducing the original anti-corrosion function of the sheathing material. shall be.

(Means and effects for solving the problems) The present invention advantageously solves the above-mentioned problems.The gist of the present invention is to drive a coated steel pipe pile, and then weld a steel bracket in advance. This is a shoring installation method for a coated steel pipe pile, which is characterized by tightening and fixing the metal band to the steel pipe pile, the inside of which is lined with a material that has a high coefficient of friction and does not corrode.

The present invention will be explained in detail below.

When attaching a pre-welded steel band to a coated steel pipe pile and using the bracket to support a superstructure such as formwork and a load, there is a shear force between the steel band and the sheathing material that is equivalent to the top load. act.

When the tightening force when installing the steel band is small, the frictional resistance between the steel band and the covering material is small, and when shearing force is applied, the steel band can safely handle the applied load of the formwork material, etc. It may not be able to support itself and may fall down.

Furthermore, if the tightening force becomes excessive, both ends of the steel band may become wedged in the covering material. Generally, steel pipe piles are made by bending a plate into a spiral cylindrical shape, or bending a plate into a U-shape.
Manufactured by welding each joint. There is a bulge in the weld bead at the weld, and the covering material also bulges to match the bulge of the bead.

Therefore, when a shearing force is applied, the end of the steel band that has penetrated may shear the entire covering material.

In order to securely transfer the tightening blade to the coated steel pipe pile,
The inner diameter of the steel band with bracket is 5 to 7 mm at the joint of the flange attached to the side of the steel band after the tightening force is introduced.
Manufactured with dimensions that allow for tightening with intervals of m. If this distance is too small, the tightening force cannot be applied reliably, and if it is too wide, the 7-lunge attachment portion may get wedged in the covering material, which is not good.

The length of the steel band is 700 to 1000 mm, and the flange is tightened with 4 to 6 bolts.

Regarding the tightening force, for example, if hard rubber or polyethylene with a thickness of 2 to 21 m is attached to the inside of a polyethylene band and a steel band as a covering material, the sliding friction coefficient between the two is μ = 0.7 to 0.8. It is. Therefore, theoretically, a shear resistance of approximately 80 inches of tightening force can be expected.

When it comes to this sliding friction coefficient, it goes without saying that the larger it is, the better.

If the safety factor of the shoring with respect to the upper load is set to 2 to 2.5, the tightening force will be approximately 2 to 3 times the load applied to the shoring.

In order to prevent the steel band from digging into the covering material, at the same time, a number of 1, for example 5 to Low, is released from the end of the steel band using hard rubber or polyethylene sheeting attached to the inner surface.
This can be solved by rounding the inner surface of the upper and lower ends of the steel band.

(Example) An embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a diagram showing an entire embodiment of the present invention, in which shoring is attached to coated steel pipes ↑ and t. The figure shows a steel band 8 with a bracket 9 welded attached to the part of the steel pipe pile 1 from which the anti-corrosion control cover 2 has been removed, and then tightened and fixed using bolts 10 to form a support. The formwork material 6 is supported through it. A test was conducted to confirm the load-bearing capacity of this structure. It is attached to a steel pipe pile with a diameter of 500 mm with 4 bolts of steel band (700 m long), and has a tightening force of 48 tons and 52 tons. A test was conducted to confirm the shear resistance. 52 tons and 55 tons respectively! to
It sufficiently resisted the shear force of n, and there were no abnormalities on the coated surface.

FIG. 2 is a detailed view of the steel band. In particular, the processing details of the end of the steel band are shown in Figure 3.

That is, a corrosion-resistant lining material 12 (for example, hard rubber, polyethylene) having a thickness t2 is stretched over a steel band 11 having a thickness t□ so that the upper and lower ends protrude from the steel band 11 by a length l. Then, when the steel band 11 is tightened to the steel pipe pile 1, the inner surface is processed into a circle with a radius half of the thickness t so that the upper and lower ends of the steel band do not sink into the lining material 12.

(Effects of the Invention) If the shoring is made and released using a band with steel brackets in this way, the superstructure and various other structures can be easily used without damaging the anti-corrosion coating of the steel pipe pile, that is, without impairing the original anti-corrosion function. can effectively support the load of

[Brief explanation of drawings]

FIG. 1 is a diagram showing one embodiment of the present invention, and FIG. 2 is a diagram showing one embodiment of the present invention.
Figure 3 shows the details of the steel band end, Figure 4 shows the conventional construction method (bracket support method)
Figure 5 is a diagram showing an example of the conventional construction method (hanging reinforcing bar method). 1... Steel pipe pile 2... Anti-corrosion coating material 3...
Horizontal beam material 4... Hanging reinforcing bar 5... Formwork support material 6... Formwork material 7... Bracket 8...
・Steel band 9... Bracket 10... Bolt 11... Steel band 12... Lining material Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] Covering characterized by driving a coated steel pipe pile, then welding a steel bracket in advance, and tightening and fixing a steel band lined with a material with a high coefficient of friction and non-corrosion to the steel pipe pile. How to install steel pipe pile shoring.