JPH0419072Y2 - - Google Patents

Description

[Detailed explanation of the idea]

Industrial Application Fields This idea is suitable for steel pipe piles and pipes used in cold regions.
Concerning countermeasures against drift ice and frozen ice for steel members for constructing water body structures such as steel sheet piles. Conventional technology (1) In areas where drift ice and ice formation occur during the winter, coastlines and river banks are eroded year after year by these ice formations. One of the countermeasures is steel pipe piles, steel sheet piles,
Anti-icing facilities such as seawalls are being constructed using underwater driven members such as steel pipe sheet piles, but in addition to normal corrosion, they are also subject to abrasion and impact from drifting ice and freezing, causing problems with the durability of the facilities. Particularly in the case of protective facilities made of concrete structures, their deterioration is significant due to freezing and thawing effects of the concrete in addition to the above. (2) In addition, lake water freezes and freezes on the surface of foundation piles for piers built in lakes and marshes, and as the water increases due to the inflow of melted snow into lakes and marshes in early spring, the frozen ice that adheres to the surface of the foundation piles increases the water level. As it rises, it moves upwards, but at this time, the foundation piles are pulled up at the same time, causing an accident in which the pier facilities are destroyed. Similar accidents have also occurred at the foundations of water intake towers in dam reservoirs. In order to prevent these accidents, the conventional method of bubbling air around the foundation piles to prevent freezing has been adopted, but this method is expensive and difficult to maintain and manage. (3) Furthermore, when river ice loosens in early spring and flows downstream, it rubs strongly against the river embankment, causing wear and tear on the river embankment, causing problems with the stability of the river embankment. For this reason, methods such as lining the entire surface of the seawall with concrete have been taken, but this has been expensive and has the problem of damaging the concrete lining. Problems to be Solved by the Invention The purpose of the present invention is to provide a technical means for advantageously solving the problems of the prior art described above, and is aimed at providing a water body structure that requires countermeasures against drift ice and frozen ice. The objective is to impart excellent anti-freezing properties, abrasion resistance, anti-corrosion properties, etc. to steel members for product construction. Means to solve the problem In other words, the present invention is applicable to rivers, lakes, marshes, etc.
Steel members for structures used in water areas such as ports and oceans must have weather resistance, seawater resistance, impact resistance, and abrasion resistance, at least in the area where drift ice or frozen ice slides due to water level fluctuations and water currents. The present invention relates to a steel member for constructing a structure that is protected against drift ice, frozen ice, and corrosion, and is characterized by using a member coated with a synthetic resin-based coating material having properties such as hardness and freeze resistance. This will be explained in detail below. The steel member according to the present invention is as described above.
These are members that require countermeasures against drift ice, frozen ice, and corrosion, such as steel pipe piles, steel sheet piles, steel pipe sheet piles, and all types of submerged steel members. Also, ice breakwater,
Examples include structural members of oil drilling rigs and the like. The present inventor investigated the possibility of covering the necessary portions of this steel member with a synthetic resin coating material. For example, when we investigated the freezing strength of various synthetic resin coating materials, particularly excellent results were obtained for polyolefin and polyurethane coating materials (Table 1). As the polyolefin type, low density polyethylene (hereinafter referred to as LDPE), medium density polyethylene (hereinafter referred to as MDPE), high density polyethylene (hereinafter referred to as HDPE) and polypropylene are preferred, and LDPE is particularly preferred. Further, as the polyurethane type, urethane type elastomer is particularly preferable. Furthermore, as the surface roughness increases, the adhesion strength also increases, but when the surface roughness is approximately 20μ or less, the adhesion strength is not affected by the surface roughness (Figure 7). This will be explained below based on the drawings. Figure 1a shows a situation in which ice 2 has frozen around the foundation pile 1, and Figure b shows a situation in which ice 2 has frozen around the foundation pile 1, and Figure b shows a situation where snowmelt water from early spring flows into lakes and marshes, so when the water rises and the frozen ice rises. This shows the situation after the foundation piles have been pulled out. In some of the Great Lakes in the United States, wooden piles such as pine are used as foundation piles, but the above-mentioned problems occur. Even when steel piles, concrete piles, etc. are used, upward pull-out force acts, so it is necessary to increase the penetration length, resulting in high costs. Figure 2 shows an embodiment of the present invention; Figure 2a shows a specific area of a foundation pile covered with the synthetic resin covering material 3 of the present invention, and Figure 2b shows that the covering material is frozen. Since the strength is extremely low, the adhesion between the coating material 3 and the frozen ice breaks at the beginning of the rise in the water level, and only the ice 2 has broken off. As the water level fluctuates, ice rises and falls and wears down the covering material, but the covering material 3 has sufficient durability against wear caused by ice. Figure 3a shows the state in which ice in a river loosens in early spring and rubs against the river bank 1 as it flows down the river, and Figure 3b shows a specific range of the members 1 driven into the ice that make up the bank. A state covered with the synthetic resin coating material 3 according to the present invention is shown. Since the coating is resistant to ice abrasion, the underwater driving parts are not damaged. In addition, the freezing strength is low and the surface is smooth, so ice flows easily. FIG. 4a shows an ice break 1 installed on the coast, which is a facility to prevent drift ice from pushing away in winter and destroying aquaculture facilities on the coast. By coating the ice breakwater with the synthetic resin coating material of the present invention as shown in Figure 4b, it is possible to reduce the ice force that acts on the ice breakwater, and also to reduce the wear and tear of the ice that rubs against the members when they slide up. It can be prevented. Fig. 5 shows an example of the invention in which steel sheet piles are covered, and Fig. 6 shows an example of the invention in which steel pipe piles are covered. Example: Bethusel, Alaska KUSKOKWIM
Polyethylene-coated steel pipe piles (polyolefin-based coating), urethane elastomer-coated steel pipe piles (urethane-based), and polymer cement-coated steel pipe piles were driven as bank protection for the RIVER, and actual exposure was conducted. In addition,
In this area, the rivers completely freeze over in the winter.
The temperature reaches 140 degrees Celsius, and as the snow melts in the spring, the ice on the river melts, causing friction (wear) on the surface of the steel pipe piles as it flows down the river. Next, we will show the exposure samples and actual exposure results. As the steel pipe pile, a 600φ x 12m spiral welded steel pipe was used, and its outer peripheral surface was coated. The products with the best exposure results were low-density polyethylene and butadiene-based urethane elastomers;
Next, high-density polyethylene, adiprene-based urethane elastomer, and castor oil-based urethane elastomer were used, but the polymer cement had a large amount of wear and some cracks occurred, so good results could not be obtained. The results are shown in Table 2.

【table】

【table】

【table】

[Table] Effects of the invention The effects of the invention are as follows: 1. Freezing strength is small. As can be seen from experimental results, the freezing strength of polyolefin-based or urethane-based covering materials is approximately 1/20 that of concrete and 1/10 that of steel, so it is difficult to protect the surface of parts cast in water. When coated with these materials, the pulling and pushing forces transmitted from frozen ice as the water level rises and falls becomes extremely small, making it possible to shorten the length of penetration of underwater parts into the soil. The ground strength at the lower end of the underwater driven member is also small. In other words, it is extremely economical because the length of penetration into the soil may be small. 2 Excellent wear resistance. As can be seen from experimental results, polyolefin-based or urethane-based covering materials wear out due to ice at about 1/20th that of concrete and about 1/2 that of steel.
Therefore, when the surface of a component driven underwater is coated with these materials, the frozen ice will slide up and down as the water level changes (at this time, the edge between the ice and the component has already been cut). It also has less wear and tear, making it 20 times more durable than concrete and twice as durable as steel. Further, when the above-mentioned submersible driven member is used in a river revetment or the like, the revetment can be made durable with less wear due to ice flowing down the river. 3 Excellent corrosion resistance. Drift ice/The areas where measures need to be taken are drift ice,
In addition to resisting abrasion due to freezing, pulling out, and pushing, it is also required to have long-term durability against salt and ultraviolet light, that is, corrosion resistance. Polyolefin coating materials or urethane coating materials have excellent long-term corrosion protection. In addition, when using steel members in ports, oceans, etc., it is important to note that when steel members are used in areas where the steel material is severely corroded (approximately 1.0
The areas affected by drift ice and frozen ice are almost the same.

[Brief explanation of drawings]

Figures 1a and b and 2a and b are elevational views, Figures 3a and b are perspective views, Figures 4a and b are elevational views, Figures 5a and c are front views, and Figure 5b is a side view of Figure 5a;
5d is a side view of FIG. 5c, FIG. 6a is a front view, and FIG. 6b is a side view of FIG. 6a. FIG. 7 is a diagram showing the relationship between freezing strength and roughness. 1...Structures (foundation piles, etc.), 2...Ice, 3...
Covering material.

Claims (1)

[Scope of utility model registration request] For structural components used in rivers, lakes, or water bodies such as ports and oceans, at least the area where drift ice or frozen ice slides due to changes in water level or water flow is coated with polyolefin or polyurethane synthetic resin. A steel member for constructing water body structures that is coated with a material that prevents drift ice and freezing.