JPS62194329A - Corrosion prevention work for steel sheet pile - Google Patents

Abstract

PURPOSE:To form a covering layer having excellent heat resistance and excellent strength on the surface of a steel sheet pile by a method in which a formwork is attached through resin bolts to the surface of a steel sheet pile, a hardening resin is injected into the space between the formwork and the pile and hardened, and then the formwork is removed out. CONSTITUTION:An auxiliary plate 25 is welded to the surface of a steel sheet pile 21 laid as sheathing for revetment, and a resin bolt 28 is screwed with the nut 26 of the plate 25. A formwork 29 is then attached through a nut 31 to the bolt 28. A hardening resin 35 is injected into the space between the pile 21 and the formwork 29 and hardened and the formwork 29 is removed out. A covering layer excellent in heat resistance and strength can thus be formed on the surface of the sheet pile 21.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for preventing corrosion of steel sheet piles, in which the surface of steel sheet piles used for earth retaining of quay walls, etc. is coated with anti-corrosion coating.

[Prior Art] Steel sheet piles, which are usually laid on quay walls as earth retainers for seawalls in ports and harbors, are driven into the seabed and then subjected to anti-corrosion treatment on their surfaces to prevent corrosion by seawater.

That is, an anti-corrosion coating is applied to the surface of the steel sheet pile to form a WI layer, but the anti-corrosion treatment of the surface of the steel sheet pile is a difficult work that involves underwater work due to the presence of water in the working environment.

Furthermore, simply pasting anti-corrosion on the surface of steel sheet piles tends to cause the anti-corrosion to peel off and flow out. In order to eliminate the shortcomings of such general anti-corrosion technology, a coating anti-corrosion device for steel sheet piles using formwork has been proposed (Utility Model Application No. 59-19
No. 659). In this coated anti-corrosion device, as shown in FIGS. 5 and 6, a plurality of steel sheet piles 1.7 are arranged so that their unevenness against the sea alternates, and is formed at both ends in the width direction. Hook-shaped joint la.

They are interconnected by 7a. A plurality of bolts 2 are welded to the surface of the steel sheet pile 1, and a convex formwork 3 made of FRP has nuts 4 screwed onto the bolts 2 via the bolts 2 so as to cover the convex surface of the steel sheet pile 1. It is fixed to steel sheet pile 1. The formwork 3 has joints 8 at both ends in the width direction, and by inserting the widthwise ends of the concave formwork 9 into the grooves formed in the joints 8, the formwork 3 and the formwork 9 can be connected. is assembled. Further, a spacer 10 is interposed between the formworks 3, 9 and the steel sheet piles 1.7, and the formworks 3, 9 are arranged at appropriate distances from the steel sheet piles 1, 7. The heads of the bolts 2 protruding outward from the formwork 3 are covered with anti-corrosion caps 5. A gap formed between the formworks 3 and 9 and the steel sheet piles 1.7 is filled with a filler 13 (foamed polyethylene).

Then, on the surface of the steel sheet pile 1.7 between the steel sheet pile 1.7 and the filler plate 113, an anti-corrosion coating layer of 1 to loratum paste and petrolatum tape (tannins and corrosive particles) is applied.
Synthesis of rust-preventing comparan 1-, which is mainly made of paraffinic hydrocarbons containing agent II! A tape made by impregnating fiber-based nonwoven fabric) is attached.

[Problems to be Solved by the Invention] However, in this conventional technique, the frame 3゜9 is used while being attached to the steel sheet pile, and since it cannot be removed from the steel sheet pile, the anticorrosion treatment costs 1 to 1 are reduced. High (Naru. Also,
Loratum, which is used as an anticorrosion coating, is an uncured agent, so when the temperature rises by -L during summer, Loratum peels off from the steel sheet pile and hangs down, creating a void between it and the surface of the steel sheet pile that was covered. will occur. Furthermore, when the vellum loratum peels off from the steel sheet pile, the petrolatum flows out into the water. Furthermore, work efficiency is low because the work of attaching petrolatum to steel sheet piles involves underwater work. Furthermore, since the required number of poles 1 and 2 is large, welding of the bolts 2 to the steel sheet pile 1 requires environmental welding for a long time in a poor working environment. Another disadvantage is that it is necessary to cover the heads of the bolts 2 fixing the formwork with caps 5 to prevent corrosion.

This invention has been made in view of the above circumstances, and it is possible to make the formwork removable so that the formwork can be used repeatedly, and to use a hardening resin as the anti-corrosion material to form a solid filling material.
The purpose of the present invention is to provide a method for preventing corrosion of steel sheet piles, which eliminates the need for anti-corrosion treatment of bolt heads and has excellent workability.

Means for Solving Problem U] The method for preventing corrosion of steel sheet piles according to the present invention involves fixing an auxiliary member in which a screw hole is formed to the surface of the steel sheet pile, and screwing a resin bolt into the screw hole. , the formwork is removably attached to the bolt, a curable resin is injected into the space formed between the steel sheet pile and the formwork, and after the resin has hardened, the formwork is removed from the bolt. .

[Function] In this invention, an auxiliary member in which a screw hole is formed is fixed to the surface of the steel sheet pile, a bolt is screwed into the screw hole, and the formwork is fixed to the steel sheet pile via this bolt. Therefore, the work of installing the formwork becomes reliably easy. In addition, since a curable resin is injected into the space formed between the steel sheet pile and the formwork to form a coating layer on the surface of the steel sheet pile, after the resin has hardened, the formwork holds down the Wi layer. No need to keep it on.

In addition, since the resin coated on the surface of the steel sheet pile hardens, the coating layer will not soften and sag due to the rise in temperature.
There is no outflow of material III from the surface of the steel sheet pile.

[Example] Hereinafter, a method for preventing corrosion of steel sheet piles according to an example of the present invention will be specifically described with reference to the attached drawings. As shown in the horizontal cross-sectional view of FIG. 1, a plurality of steel sheet piles 21 each having a U-shaped cross section are disposed continuously in the width direction, separating the sea from the land, and a retaining wall is formed on the quay. The steel sheet pile 21 has joints 22 having a hook-shaped cross section and extending in the longitudinal direction at both ends thereof in the width direction. Adjacent steel sheet pile 21a by this joint 22
and 21b are connected to each other, and the steel sheet pile 21a has a convex surface 23,
The steel sheet pile 21b has a concave surface 24 facing toward the sea. Convex surface 23
Auxiliary plates 25 extending vertically are welded and fixed to the concave surfaces 24, respectively. Bolts 28 are screwed into a plurality of screw holes provided in this auxiliary plate 25, respectively.
8 and nuts 31 to attach the FRP formwork 29 to the steel sheet pile 2.
Fix it to the sea side surface of 1. As a result, multiple steel sheet piles 21
A plurality of formworks 29 are connected along the direction in which they are arranged,
A formwork 29 is arranged to cover the steel sheet pile 21. The formwork 29 extends in the vertical direction, and when the formwork 29 adjacent to each other is assembled in the width direction, it becomes a shape that follows the uneven surface of the steel sheet pile 21, and the width of the four sides 24 from the center of the width of the convex surface 23. It is formed to cover the area in the width direction up to the center of. Further, a plurality of bolt holes arranged in series are formed at both ends of the formwork 29 in the width direction. And the adjacent formwork 29
Overlap one end in the width direction of each of formwork 29a and formwork 29b, align these bolt holes, and insert FR into each bolt hole.
A formwork 29a and a formwork 29b are fixed to the surface of the steel sheet pile 21a by passing resin bolts 28 made of P into the steel sheet pile 21a. Further, a resin spacer 27 having a predetermined thickness is provided between the formwork 29a and the steel sheet pile 21a, and a gap 35 of an appropriate length is formed between the formwork 29a and the steel sheet pile 21a. This resin spacer 2
7 is a circular plate or rectangular plate of a predetermined thickness with a bolt hole formed in the center, and is fixed between the formwork 29 and the steel sheet pile 21 by inserting a resin bolt 28 into the bolt hole. . Further, a rubber sealing material 30 is interposed at the overlapping portion of the molds 29a and 29b. A nut 31 is screwed onto a resin bolt 28 that protrudes from the outside of the rubber sealing material 30 to the outer surface of the overlapping formwork 29b.

As shown in the vertical sectional view at the position of the formwork installation in FIG. 2, the steel sheet pile 21 with its lower half immersed in the sea is vertically disposed to separate the sea from the land.

The formwork 29 is installed so as to cover the underwater and offshore parts of the steel sheet pile 21a.
a and 29b are provided. Formwork 29a.

A plurality of bolt holes arranged vertically at predetermined intervals are formed at the end of the width direction of the 29b, and resin bolts 28 are inserted into each of the bolt holes, and then the nuts 26 of the auxiliary plate 25 are inserted through the spacers 27. are screwed together. Formwork 29a, 2
A release agent (not shown) is applied to the land side (steel sheet pile 21 side) surface of 9b. Further, a rubber sealing material 30 having a predetermined thickness is sandwiched between the overlapping portions of the molds 29a and 29b, and is arranged from the upper end to the lower end of the molds 29a and 29b along the vertical direction. There is. On the other hand, resin spacers 32 are fitted into various parts of the lower opening of the cavity 35, and a rubber sealing material 33 having a predetermined thickness is filled over the entire length of the lower opening to close the opening. A plurality of injection ports 38 for injecting resin into the underwater immersed portion of the formwork 29 are provided at a position above the filling position of the rubber sealing material 33.

Attachment of the formwork 29 will be explained with reference to FIG. An auxiliary plate 25 having a plurality of steel nuts 26 is welded and fixed to the surface of the steel sheet pile 21a, and a resin bolt 28 is screwed into the nuts 26. Resin spacer 27, formwork 29a1, rubber sealing material 30, and formwork 2, each having a bolt hole
9b is inserted into the resin bolt 28 in this order, and then the nut 31 is screwed together, and the bolt 9b is inserted into the formwork 29a at a distance from the steel sheet pile 21a.
, 29b are fixed.

With reference to FIG. 4, the auxiliary plate 25 welded and fixed to the steel sheet pile 21 will be explained. Auxiliary plates 25 are provided on each of the convex and concave surfaces of the steel sheet pile 21 and extend in the vertical direction.

The offshore part of this auxiliary plate 25 and the steel sheet pile 21 are fillet welded 3
The auxiliary plate 25 is fixed by welding intermittently by 7. On the other hand, a plurality of rectangular holes for fitting hexagonal nuts 26 are provided in series at the center of the width of the auxiliary plate 25, and the nuts 26 are fitted into these holes and fixed by welding 36. The mutual spacing of the nuts 26 corresponds to the vertical spacing of the bolt holes in the formwork 29.

In the method for preventing corrosion of steel sheet piles according to the embodiment of this invention,
When a plurality of steel sheet piles 21 are driven into the seabed and laid, the steel sheet piles 2
To install the auxiliary plate 25 in step 1, remove rust etc. from the surface, weld and fix the auxiliary plate 25 to the convex surface 23 and concave surface 24 of the steel sheet pile 21, respectively.
A plurality of resin bolts 28 are screwed into the nuts 26. In addition,
The resin bolt 28 may be screwed into the nut 26 in advance before the auxiliary plate 25 is welded and fixed. And resin bolt 28
A resin spacer 27 is fitted into each. On the other hand, before installing the formwork 29, apply a molding agent to the land side (steel sheet pile 21 side) surface of the formwork 29, hang these formworks 29 on the quay, and fix them with the bolt holes of the formwork 29a. The formwork 29a is positioned so that the resin bolts 28 are aligned with each other. Then, insert the resin bolt 28 into the bolt hole of the formwork 29a, and
Install 9a. Next, the rubber sealing material 30 is attached to the resin bolt 28, the formwork 29b is positioned, and the resin bolt 28 is
Install it on 8. Finally, the nuts 31 are screwed onto the resin bolts 28 and tightened to fix the forms 29a, 29b to the surface of the steel sheet piles 21a. Furthermore, by the same assembly procedure, formwork 29b and formwork 2 are attached to the surface of adjacent steel sheet pile 21b.
Fix 9c. In this way, the formworks 29 are successively fixed to the surfaces of the adjacent steel sheet piles 21, and the formworks 29 are fixed to the surfaces of the steel sheet piles 21.
Place it on the surface. Note that the resin spacer 27 and the rubber sealing material 30 are adhered in advance to the land side surface of the formwork 29a, and the formwork 2
It may be assembled integrally with 9a. After fixing the formwork 29, a gap 35 is formed between the steel sheet pile 21 and the formwork 29.
A plurality of resin spacers 32 are fitted into the lower opening at appropriate length intervals, and a rubber sealing material 33 is packed to a predetermined thickness over the entire area of the lower opening to close the lower opening. Then, the supply ports (not shown) of resin supply pipes are connected to the plurality of injection ports 38 of the formwork 29, respectively, and the underwater curable Inject epoxy resin. Note that other curable resins may be used instead of the epoxy resin as the curable resin filled in the voids 35. When the epoxy resin hardens over time after injection, the nuts 31 are loosened and the formwork 29 is removed.

After removing the formwork 29, the cured layer of epoxy resin (N layer)
The head of the resin bolt 28 protruding from is cut off and removed. In addition, when using the formwork 29 in a state fixed to the steel sheet pile 21, no release agent is applied to the inner surface of the formwork 29.

Since the formwork 29 can be removed from the steel sheet pile 21 in this way, the two removed formworks can be used repeatedly.

In addition, the vertical bolt hole spacing of the formwork 29 and the auxiliary plate 25
Since the vertical nut hole spacing of the mold is made to match before installing the formwork, the work of installing the formwork becomes easier. Then, in step (4), an underwater curable epoxy resin is used as the curable resin coated on the steel sheet pile 21 to form a coating layer with excellent adhesive strength and compressive strength, and the N layer to be coated with heat softens and sags. It is possible to prevent the WI layer from flowing out from the surface of the steel sheet pile. Further, conventionally, a large number of bolts were required to secure the formwork, but in the present invention, since the coating layer and the steel sheet pile have good adhesion, the number of bolts required can be reduced. Furthermore, since the resin is injected through the injection port provided in the formwork, there is no need to apply corrosion protection underwater. In the formwork assembly work, the proportion of underwater work is reduced, so the efficiency of the anticorrosion treatment work is improved. Furthermore, since resin bolts and spacers are used as fixing members, these are integrated with the epoxy resin after hardening, making the entire coating layer uniform, improving the strength of the target III, and improving the strength of the bolts. Corrosion prevention treatment for the head, etc. is no longer necessary.

[Effects of the Invention] According to the present invention, when a curable resin is used, the coating layer does not soften and sag during the summer when the temperature rises, and the coating layer does not flow out into the water.

In addition, since the adhesion between the steel sheet pile and the coating layer is good, there is no need to hold down the coating layer with the formwork, and the expensive formwork can be removed from the steel sheet pile and used repeatedly, reducing the cost of anti-corrosion treatment. It is possible to reduce the Furthermore, since resin ports and spacers are used as fixing members for the formwork, these are integrated with the resin after curing, making the coating layer uniform as a whole, improving the strength of the coating layer, and , it is possible to eliminate the need for anti-corrosion treatment of bolt heads, etc.

In addition, by using auxiliary members to fix the formwork, the number of bolts required to fix the formwork to the surface of the steel sheet pile can be reduced, and workability is improved. Furthermore, since the positions of the screw holes on the auxiliary member and the bolt holes on the formwork are matched before installing the formwork, the positioning of the formwork can be done reliably and easily, making the work of installing the formwork easier. Efficiency can be improved. In addition, since the formwork is fixed via the auxiliary plate, reinforcing materials that were required when the formwork was fixed only with bolts are no longer required, and the work can be simplified.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view in the width direction of a steel sheet pile showing an embodiment of the present invention, Fig. 2 is a sectional view in the longitudinal direction of the steel sheet pile, Fig. 3 is a partially enlarged view of Fig. 1, and Fig. 4 is an auxiliary drawing. FIGS. 5 and 6 are schematic diagrams showing how the plate is attached, and FIGS. 5 and 6 are cross-sectional views in the width direction and longitudinal cross-sectional views of the prior art. 1.7.21.21a, 21buX++-eI: Steel sheet pile, 3; Formwork for convex surface, 8.22: Joint, 9: Rubber sealing material, 32; Resin spacer, 35: Gap, 38
; Inlet applicant's agent Patent attorney Takehiko Suzue Figure 3 1J Kaikaku 62-F432! J (e5) Figure 5 Figure 4 1

Claims (1)

[Claims] An auxiliary member with screw holes is fixed on the surface of the steel sheet pile,
A resin bolt is screwed into this screw hole, a formwork is removably attached to this bolt, a hardening resin is injected into the space formed between the steel sheet pile and the formwork, and this resin is hardened. A method for preventing corrosion of steel sheet piles, which is characterized by removing the formwork from the bolts afterwards.