JPS5953414B2 - Corrosion-resistant cover - Seal structure at the bottom end - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sealing structure for the lower end of a corrosion-resistant cover.

Corrosion prevention work is already known in which, in order to protect steel pipe supports installed in ports and the like, the tidal range of the support is covered with an F-R-P cover, and mortar or the like is filled between the support and the cover and solidified.

In this case, the problem is the seal between the lower end of the cover and the column, but conventionally the lower end of the cover is curved inward or a separate bottom plate is provided in a similar shape, and an elastic annular band is added to the inner end. A seal structure was adopted in which the inner end of the annular band was pressed against the outer surface of the support column by its own weight when it was installed and filled with mortar.

If the lower end of the corrosion-resistant cover is also pressed against the outer surface of the support column, the sealing effect will be perfect in conjunction with the annular band, but in order to do so, the inner diameter of the lower end of the cover must be made smaller than the outer diameter of the support support. This, of course, makes it extremely difficult to place the cover over the support.

Therefore, the work of putting the cover on the support can be done without any problem.
When attaching the cover, a double seal structure can be achieved if the lower end can be pressed into contact with the support post later.

However, in order to put it to practical use, it is necessary that the pressure welding operation can be performed easily.

The present invention has been made to achieve this objective.The lower end of the cover is curved inward and upward, an elastic annular band is attached to this, and a filler with a large expansion rate is injected, and when this solidifies, not only the annular band but also the elastic band is attached. The lower end of the cover is also in pressure contact with the outer surface of the support column.

In this way, there is no need for any special work to bring the lower end of the cover into pressure contact with the outer surface of the support column, and a double seal structure can be achieved.

Ordinary mortar has a small expansion rate, and the lower end of the F-R/P cover will not deform due to its own weight. Therefore, in order to carry out the present invention, a special filler as described below must be used. It won't happen.

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

Figure 1 shows the F-R-P corrosion protection cover 2 installed on the steel pipe support 1.
Fig. 2 is an enlarged cross-sectional view of the lower end of , shown before injection of filler.

The lower end 3 of the cover 2 is curved diagonally upward inward,
An elastic annular band 4 is attached to this inner end as the actual sealing element.

The annular band 4 is suitably made of an elastic material with high friction such as rubber, and its outer end is fixed to the inner surface of the cover lower end 3 by a fastening member 5 such as a screw or rivet, and its inner end is in contact with the outer surface of the support column 1. are in contact with each other.

The length S' of the lower end portion 3 of the cover is formed to be slightly larger than the radial distance S between the cover 2 and the support column 1.

However, since the lower end portion 3 is bent inward and upward, that is, at an acute angle, its tip does not touch the outer surface of the support column, and therefore, no problem occurs when the cover 2 is placed over the support column 1.

In the embodiment shown in FIG. 1, the lower end 3 of the cover 2 is directly curved, but another member such as a bottom plate may be attached to the straight lower end of the cover.

When a filler 6 with a high expansion rate as described later is injected into the annular space of the corrosion-resistant cover 2 installed in this way, the cover 2 swells slightly as shown in FIGS. 2 and 3, and the annular band 4 is completely removed. Press against the outer surface of the support.

Furthermore, the cover lower end 3 is also pressed downward by the expansion force of the filler 6, and its tip comes into pressure contact with the outer surface of the support column.
A double seal is formed between and strut 1.

Since the cover lower end 3 has a restoring force based on elasticity, and the tip of the cover lower end 3 is in pressure contact with the outer surface of the support column, the expansion force of the filler 6 will not cause the cover to deform too far below the horizontal position. .

The applicant conducted an experiment regarding the double sealing effect and the above-mentioned problem by diving into the sea and confirming the lower end of the cover.

The filler used in this invention is made by mixing an expanding material with cement or the like.

There are various types of expanding materials, but one commercially available from Onoda Cement Company under the trade name "Expan" is preferred.

This material is mainly composed of free calcium oxide (expandable Cab) and also contains calcium silicate and a glassy phase, and has a higher expansion force and strength compared to conventional expandable materials that utilize hydration expansion due to ettringact. Are better.

Of course, conventional products can also be used as long as they have a large expansion coefficient.

As described above, with the cover lower end structure of the present invention, the second advantage is obtained that double sealing can be easily achieved and the cover installation does not pose any problem during construction.

Although the above embodiments have been described using steel pipe struts as an example, it will be understood that the present invention can be used to double-seal the corrosion-resistant covers of not only struts but also steel sheet piles, continuous struts, and other structures. .

Therefore, the present invention is not limited to the above embodiments.

[Brief explanation of the drawing]

Fig. 1 is an enlarged vertical sectional view of the lower end of the cover before the filler is injected, Fig. 2 is a longitudinal sectional view after the filler is injected and solidified, and Fig. 3 shows the whole. FIG. 1... Steel pipe support, 2... F-R-P corrosion protection cover, 3
... lower end of cover, 4 ... annular elastic band, 5 ...
Fastening member, 6...Filler, S...Radial distance between the support column and cover, S'...Radial length of the lower end of the cover.

Claims (1)

[Scope of Claims] 1. A corrosion prevention device that covers the ebb and flow area of structures such as steel pipe supports and steel sheet piles installed in ports, etc. with a cover, and injects and solidifies a filler into the space formed between the cover and the structure. , bending the lower end of the cover inward at an acute angle, making the length of the lower end slightly longer than the distance between the cover and the structure, and fixing one end of the elastic sealing member to the inside of the lower end. At the same time, the other end of the sealing member is pressed against the outer surface of the structure, and a filler with a high expansion coefficient is injected into the space, and the inner end of the lower end of the cover is also pressed against the outer surface of the structure by this expansion pressure. Features a seal structure at the bottom end of the corrosion-resistant cover.