KR900001101B1 - Frost damage proofed pile - Google Patents

Abstract

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Description

East Sea prevention pile

1 to 3 show a conventional method for reducing kinetic frost force.

1 is an explanatory diagram of a thermal pile method.

2a and 2b are explanatory diagrams of the anti-frost pile method.

3 is an explanatory diagram of the pile strength increase pile method.

4 is a longitudinal sectional view of an embodiment of the present invention.

5 is an explanatory diagram of its operation.

6A and 6B are enlarged sectional views of principal parts showing an example of the configuration of the stretchable member of the coating member used in the present invention.

7 is a longitudinal sectional view of another embodiment of the present invention.

8 is an explanatory diagram of its operation.

9 is a longitudinal sectional view of another embodiment of the present invention.

10 is an explanatory diagram of the operation.

11 is a longitudinal sectional view of the main part.

12A is an enlarged cross sectional view of a main portion of another embodiment of the present invention.

Figure 12b is a diagram explaining its operation.

13A to 13D are schematic views each showing an example of the shape of the stretchable portion of the covering member.

14 is a conceptual diagram of a device for experimenting with the East Sea prevention pile according to the present invention.

FIG. 15 is a diagram showing changes over time in the amount of frostbite between conventional steel pipe piles and the East Sea-protected piles according to the present invention. FIG.

FIG. 16 is a diagram showing changes over time in the same kinetic history.

* Explanation of symbols for main parts of the drawings

1: antibody 1a: solid film

5: permafrost 6: active floor

8: Sand Slurry 10, 10a: East Sea Prevention Pile

11, 11a, 21: covering member 12, 23, 24: stretchable part

17: fluid material 30, 30a: pile member

The present invention relates to pile foundations among structural foundations in the cold zone, and more particularly, to the East Sea prevention pile.

In the case of building pipelines and other structures in a cold district called the Permafrost or Seasonal Frozen Zone, it is essential to protect the structure from the East Sea such as frozen ground and melting sedimentation of active and seasonal frozen ground layers. . For this reason, although it is used for various measures construction methods, the most common thing is a pile foundation.

Permafrost here, for example, Alaska, Canada. Regardless of seasons such as Siberia, it refers to the area where the freezing strata (hereafter called permafrost) are distributed throughout the year. The average annual temperature is below 0 ℃.

The active layer is a part from the surface to the permafrost layer, which is frozen and rising in the winter season and melted and settled in the summer due to the great influence of temperature changes throughout the year. In addition, seasonal frozen ground layer refers to an area where the average temperature without permanent frozen ground layer is below 0 ℃ and freezes in winter season and melts in summer season.

Moreover, in the above description, seasonal frozen ground is included in the active layer.

However, pile foundations in the cold districts are deeply driven into the permafrost and try to counteract the weight, freezing and reverse friction of the superstructure according to the frozen strength between the permafrost and the pile surface. It is necessary for the pile to be embedded in the ground with sufficient depth to ensure a firm bond between the frozen ground and the pile.

However, the permafrost layer does not necessarily have uniform properties, and there is a big difference in the cohesive strength depending on the soil temperature, so in design, even if the piles are deeply embedded in the permafrost to ensure sufficient cohesive strength, the structure is not subjected to freeze damage. Because of the frequent design, increased safety factor had to be embedded in the ground, so there was a big problem in constructability and economic feasibility.

Because of these preconditions, some countermeasures have been studied to reduce the freezing force acting on the pile foundation.

1 to 3 show the method of reducing the cohesion of pile foundations, which is conventionally practiced in the permanent and seasonal winter lands. FIG. 1 shows the thermal pile method and FIG. 2 shows the frost-free pile method. 3 is the method of increasing the strength of the bond strength.

1 is a longitudinal sectional view showing an example of the thermal pile method, in which (1) is an antibody consisting of a steel pipe term, a concrete term, etc., and (2) a wrinkle formed on the outer circumference of the antibody (1) due to increased cohesive strength. Formation (3) is the heat pipe mounted in the antibody (1), (4) is a radiator. (5) is the permafrost layer, (6) is the active layer, and the antibody (1) is embedded in the excavation hole (7) provided in the active layer (6) and the permafrost layer (5) and backfilled with sand slurry (8). (back filling)

Furthermore, H represents the thickness of the active layer 6 which is the depth at which the antibody 1 is embedded in the ground and h.

In this thermal pile method, the temperature of the permanent passage 5 in the portion where the antibody is embedded is forcibly cooled by the height pipe 3 during the winter season to accumulate cold heat (active layer 6). Is to reduce the thickness h) and increase the anti-freeze. Furthermore, this thermal pile can prevent the permafrost of the main surface of the antibody 1 from melting due to heat input from the superstructure in the summer. In other words, the thermal pile method prevents negative friction from acting on the pile along with the settling of the permafrost around the pile and freezes the melt more than necessary by freezing the melt in the winter can do.

However, the thermal pile can reduce the thickness h of the active layer 6 somewhat, but it cannot be reduced as much as the contemplated kinetic force and reverse friction, and still cannot prevent the freeze damage of the structure. For example, in the winter of the first year of use, as the ground core temperature decreases, the amount of soil rises more than in the case of not using the thermal pile.

In addition, it can be considered that the temperature decrease of the active layer tends to increase the copper frost power even after the second year. In the conventional use example, the depth H to be embedded in the permafrost of the thermal pile was considerably long to prevent the east sea, but there was a problem in the economic feasibility of construction.

The frost-free pile method is filled with a material that can prevent the adhesion between the pile and the permafrost between the active layer and the main surface of the pile, and as shown in FIG. 2a, casing concentrically with the outside of the antibody (1). (9) is arranged in a double tube manner and the gap between the antibody (1) and the casing (9) is filled with a mixture of oil and wax of high concentration (10) so that the outer circumference of the casing (9) is sand slurry (8). By filling with the back, the kinetic power is separated.

Moreover, 9a is a flange provided in the lower end of a casing. In addition, shown in FIG. 2 (b), the active layer 6 portion of the hole 7 in which the pile is erected is used as the backfilling material of the material 10a mixed with soil, oil and wax.

This method of frostbite prevention prevents filling or backfilling of a mixture of oil and wax on the main surface of the pile, but it must be installed in the field and therefore requires not only machinery or equipment, but also in terms of workability. Not good.

In addition, since the mixture of oil and wax has fluidity enough to be filled in the mold, the backfill material penetrates into the surrounding ground in the summer and is dispersed. This causes the need for recharging or dissolves the permafrost due to the freezing point drop. Environmental destruction to say occurs.

In addition, in the double tube method, as the freezing of the active layer melts, the casing may be lifted or lowered, which may adversely affect the superstructure.

3 shows the method of increasing the bond strength, and the permafrost (5) and the antibody (1) are provided by providing notch or wrinkle formation (2) in the portion embedded in the permanent passage (5) of the antibody (1). ) To increase the cohesion strength between the active layer (6) to counteract the cohesion.

In this method, the characteristics of the permafrost in the part where the antibody (1) is embedded in the ground are not necessarily uniform, and imbalance occurs in the cohesive strength. In order to obtain, there existed a problem of requiring the manufacturing process of considerable precision, for example, the mold release processing of the edge part.

In addition, the East Sea Prevention Pile must use a length corresponding to the thickness (h) of the active layer (6) at the installation site, but the thickness (h) of the active layer varies considerably depending on the area and place. Piles of various lengths corresponding to the thickness of the layer 6 had to be prepared.

Because of this fact, when installing pile foundations over long distances, for example, as a platform for pipelines, the piles of various lengths are manufactured in the factory in advance and transported to the site to transport the active layer 6 The pile corresponding to the thickness was selected and installed.

For this reason, not only the packaging is inconvenient, but also the transportation of the articles is large, and it is not convenient for mass production.

It is an object of the present invention to achieve a conventional problem as described above to form a solid film on the surface of the antibody and at the same time the member to reduce the cohesion force acting on the pile by the freezing of the active layer and seasonal frozen ground layer antibody In addition to this, it is to obtain the East Sea Prevention Pile, which can prevent the East Sea received by the superstructure.

Furthermore, another object of the present invention is to realize the East Sea prevention pile that can adjust the length of the pile in response to the thickness of the active layer and seasonal frozen ground layer, mass production is possible and transportation is easy to reduce the cost.

The anti-corrosion pile according to the present invention is a trap of at least part of an antibody formed by forming a solid film on a surface in advance in a pile of a type that reduces the cohesion and reverse friction acting on the pile in a cold district to achieve the above object. Covering the cover member having a shaft and having a thickness greater than or equal to the thickness of the active layer or the seasonal frozen ground layer, the lower end of the active layer or the frozen ground layer, or near the bottom of the active layer or the seasonal frozen ground layer, or, if necessary, the upper portion above the ground surface, It is fixed and filled with a fluid material such as gas and liquid in the space formed by the solid coating and the coating member, and has a length obtained by cutting a plurality of normal piles, and the trail to the antibody formed by forming a solid coating on the surface in advance. The upper and lower ends of the coating member of the trailing shaft part are covered with the antibody having the shaft portion, and the upper and lower ends thereof are placed inside the upper and lower ends of the antibody. It is fixed and filled with a fluid material such as gas and fluid in the space formed by the solid coating and the coating member to form an anti-member, and the anti-member is properly connected to correspond to the thickness of the active layer or the seasonal frozen ground layer.

Next, the present invention will be described with reference to the drawings.

4 is a longitudinal sectional view of an embodiment of the present invention.

In addition, the same parts as those in FIGS.

In the figure, (1) is an antibody, and the solid film 1a having the same thickness is sprayed or formed by other means in the range slightly longer than the thickness of the surface, preferably the active layer 6.

(11) is a covering member having a corrugated trail shaft portion 12 in the middle and provided with cylindrical portions 13 and 14 at the upper and lower portions thereof, and the upper cylindrical portion 13 is preferably a cylinder further upward and downward from the ground surface. The portion 14 is tightly fixed to the antibody 1 along the fixing members 15 and 16, respectively, near or below the boundary between the active layer 6 and the permafrost layer 5.

Reference numeral 17 denotes a fluid substance filled in a space formed by the solid coating 1a and the coating member 11 of the antibody 1.

FIG. 6A is an enlarged view of the main portion of the trailing shaft portion 12 of the covering member 11, where the ratio of XYZ and XZ in a state in which no load is loaded is determined by the thickness h of the active layer 6; It may be larger than the ratio between the maximum value and the minimum value over one year, and the shape of the trailing shaft portion 12 may be a straight line as shown in FIG. 6B in addition to a sine curve arc.

Further, the minimum diameters X and Z of the covering member 11 are preferably in contact with the solid coating 1a in order to reduce the filling amount of the flowable material 17. However, the present invention is not particularly limited thereto and may be separated.

The solid coating 1a used in the present invention satisfies these conditions under the condition that the friction coefficient for the coating member 11 is smaller and the coating surface of the antibody can be coated. Representative examples thereof are shown in Table 1.

In addition, the coating member 11 used in the present invention varies depending on the region, but generally ① brittle fracture does not occur from room temperature to a low temperature of about -50 ° C, and ② recoverable displacement Table 2 shows a representative example that satisfies these conditions, provided that is greater than the freeze-phase amount (h ₁ -h) of the active layer 6, and e. It was. Furthermore, although the fluid substance 17 varies depending on the region, it generally shows ① the flow behavior from room temperature to the low temperature of about -50 ° C, and ② does not deteriorate or corrode the antibody (1) and the coating member (11). Representative examples satisfying these conditions and satisfying these conditions are shown in Table 3.

TABLE 1

The East Sea Prevention Pile constructed as above is usually installed according to the following method.

(1) Excavate the active layer (6) and the permanent furnace layer (5) only at the buried depth (h + H) of the pile (10), and pile the pile (10) in the excavation hole (7), and then pile (10). Backfill the sand slurry (8) around). Where h is the thickness of the active layer (6), H is the depth of the pile embedded into the permafrost layer.

(2) When the strength of the permafrost layer (5) is relatively small, or when the pile roots are embedded in the ground that has not yet been frozen, excavate only the active layer (6) and drive the pile (10) into the excavation hole (7). The slag is struck into the permafrost or into the land that has not yet been frozen, and the sand slurry 8 is finally filled around the pile 10 of the active layer 6.

Next, the action of the anti-frost pile according to the present invention installed as described above will be described with reference to FIGS. 4 and 5. FIG.

4 is a view showing the state and the state of the summer installed in the excavation hole 7 excavated in the active layer 6 and the permafrost layer 5 in accordance with the present invention. When the active layer 6 is frozen and frozen, the sand slurry 8 is also frozen to adhere to the surface of the covering member 11 of the pile 10.

On the other hand, a fluid material 17 is filled between the solid coating 1a of the antibody 1 and the coating member 11, and the solid coating 1a and the coating member 11 formed on the antibody 1 are interposed therebetween. Since the friction coefficient of is smaller than the friction coefficient between the antibody 1 and the coating member 11, the sliding resistance between the solid coating 1a and the coating member 11 is small.

For this reason, when the active layer 6 is in phase, as shown in FIG. 5, the coating member 11 also follows this, and is subsequently raised by the antibody 1 and stretches. However, since the upper and lower cylindrical portions 13 and 14 are fixed to the antibody 1, the expanded portion 12a is formed along the fixed portion along the elongated trailing shaft portion 12.

As the covering member 11 extends, the flowable material 17 filled between the antibody 1 and the covering member 11 moves upward and collects in the inflation portion 12a formed thereon.

As described above, the cohesion force of the active layer 6 on the antibody 1 is absorbed by the coating member 11 and the fluid 17 and is not transmitted to the antibody 1.

In addition, since the fluctuation of the active layer 6 is large depending on the region, and a large amount of fluid is collected in the expansion part 12a, when the expansion part 12a is damaged and the fluid material 17 may leak, the tank 18 ) May be provided to communicate with the inflation portion 12a and flow out of the fluid substance 17 collected in the inflation portion 12a.

When the active layer 6 melts and settles in the summer, the covering member 11 also descends and returns to the state of FIG.

Furthermore, reverse friction generated by dissolution sedimentation of the active layer 6 is absorbed by the fluid 17 and hardly acts on the antibody 1.

By the way, the East Sea prevention pile constructed as described above has the wintering and freezing phase of the active layer and the summer and the melting sediment, the coating member 11 is wound and stretched following the antibody 1, especially the inner wall of the small diameter part is always The surface of the antibody is rubbed to rub it.

For this reason, the part which rubs and contacts the antibody 1 of the covering member 11 is severe, and it is easy to be damaged. In particular, when gas is used as the flowable material 17, since there is no effect of reducing wear, the damage is remarkable and it cannot withstand long-term use.

However, in the present invention, since the solid film 1a having the coefficient of friction with the coating member 11 is formed on the surface of the antibody 1 with a smaller coefficient than that of the antibody 1, the coating member 11 is hardly damaged and therefore, for a long time. Withstand the use of

7 is a longitudinal cross-sectional view of another embodiment of the present invention, in which the same parts as in FIG. 4 are denoted by the same reference numerals, and description thereof is omitted.

In the present embodiment, the ordinary portion 22, the upper elastic portion 23, and the lower elastic portion 24, which are configured separately, are integrally combined to form a covering member 21, and the upper elastic portion 23 is formed on the ground surface. The upper and lower portions of the stretchable part 24 were fixed to the antibody 1 by fixing members 15 and 16 at or near the boundary between the active layer 6 and the permafrost layer 5, respectively. The fluid material 17 is filled between the solid film 1a formed in the c) and the coating member 21.

Moreover, the combination and installation method of the material (material) quantum constituting the covering member 21 and the flowable material 17 is the same as the case described in the embodiment of FIG.

7 shows a state in which the anti-freeze stack 10a is installed in the excavation hole 7 and the state of the summer.

When the active layer 6 of the winter system freezes, as shown in FIG. 8, the normal part 22 and the lower extensible elastic part 24 are raised to extend the lower extensible elastic part 24 as shown in FIG.

As a result, the upper elastic portion 23 is deformed to form the expansion portion 23a, and the above-mentioned fluid material 17 is accommodated by the extension of the lower elastic portion 24. The rest of the operation is almost the same as in the embodiment of FIGS. 4 and 5.

9 is a longitudinal sectional view showing an embodiment of the second invention.

The present invention connects the anti-members 30 and 30a by providing a shade-shaped coating member 12a to an antibody 1 'of an appropriate length having a solid film 1a formed on its surface. 30) An example of the configuration is shown in FIG.

1 'is an antibody, and the length 1 is selected by the length which cut | disconnected the normal pile several times (for example, 0.5m).

The solid film 1a shown in Table 1 is formed on the surface of this antibody 1 ', and the shade-shaped covering member 11a is fixed so that its upper and lower ends are only 11 and 12 inside at the end of the antibody 1a, respectively. It is tightly fixed to the antibody 1 'according to the members 15 and 16, and the fluid 17 is filled between the solid film 1a and the coating member 11a.

The anti-member 30 constructed as described above is produced at the factory and transported to the site after being erected, and the pile members 30, 30a ... are fitted to the end of the antibody 1a as shown in FIG. And a length corresponding to the thickness h of the active layer 6 with the welding lamp 31.

The East Sea prevention pile 10 constructed as described above is active because the cover member 11a of each pile member 30, 30a ... is deformed as shown in FIG. 10 when the winter active layer 6 is frozen. The normal force of the layer 6 is not transmitted to the antibody 1a. The action when the active layer 6 melts and precipitates in the summer is approximately the same as in the case of the fourth and fifth embodiments.

Figure 12a is a cross-sectional view showing the main part of another embodiment of the present invention.

In this embodiment, each ring 25 is opened between the large diameter portion of the corrugated decorative shaft portion 12 of the coating member 11 and the fixed coating 1a of the antibody 1, and thus the sand slurry 8 It is possible to prevent deformation or breakage of the trailing and contracting portion 12 caused by the pressure of the active layer 6 via).

(b) shows the relationship between the antibody 1, the coating member 11, and the ring 25 when the active layer 6 was frozen.

Furthermore, the ring 25 may be opened on the outer circumference of the small diameter portion of the trailing shaft portion 12 or may be buried in the trailing shaft portion 12.

Furthermore, in the present invention, the trailing shaft portion 12 of the covering member 11 is formed in a spiral shape, and the coil spring is retrofitted to the small diameter outer wall or the spring between the large diameter inner wall and the solid film 1a, or both. May be filled with the trailing shaft portion 12.

Thereby, the deformation | transformation or damage of the trailing-shaft part 12 can be prevented, and return of the trailing-shaft part 12 can be reliably performed at the time of settling of the active layer 6 in the summer.

The shape of the trailing shaft portion of the covering member is shown in each embodiment, but the present invention is not limited thereto, and various shapes may be used, for example, as shown in FIGS. 13A to 13D.

Next, the experimental results of the case where the conventional steel pipe pile is used as it is in the cold zone and the case of using the anti-frostbite pile according to the present invention will be described.

In the experiment, the same apparatus as in FIG. 14 was used.

The device was interlaced with a reaction force frame 33 between the frames 32 and 32, which were placed on the base 31, and surrounded by a 100 mm thick insulation 34 on the base 31. A soil bucket (35) filled with soil (36) is installed between the model pile (37) and the reaction frame (33) in which the model pile (37) is placed in the soil (36). By displacing the cell 38, a displacement meter 39 for measuring the displacement of the surface of the soil 36 in the soil container 35 is provided.

Experimental Example

(1) Steel pipe piles (conventional)

Outer diameter: 34mm, length: 400mm, embedding length: 250mm

(2) Copper seam prevention piles (corresponding to the embodiment of FIG. 4)

(a) the material and dimensions of the antibody

Material: Steel Pipe Pile

Outer Diameter: 27.5mm, Length: 400mm

Buried Length: 250mm

(b) Material and dimensions of solid coating

Material: Low Density Polyethylene

Thickness: 1mm

(c) material and dimensions of covering members;

Material: Low Density Polyethylene

Thickness: 1.0mm, Floor pitch: 9.0mm, Floor and valley difference: 6.0mm, Covering length: 300mm

(d) fluid substances

air

The conventional steel pipe pile and the East Sea prevention pile according to the present invention are placed in the experimental apparatus shown in FIG. 14, respectively, and then the experimental apparatus is installed in a freezer compartment, started at room temperature, cooled to -20 ° C, and cooled for about 24 hours. After elapsed, the temperature was changed to −40 ° C. and the state was continued for about 48 hours, and then cooling was stopped.

The time-dependent change in the amount of frostbite of the soil 36 in the soil container 35 was measured by the displacement meter 39, and the change in time-dependent change of the co-bonding force was shown in FIG. The results measured in Fig. 16 are shown in Fig. 16 (A in the drawing is the conventional steel pipe pile, B is the experimental result of the East Sea prevention pile of the present invention).

As apparent from the drawings, the frostbite amount is approximately 0.5, even though both have little change in the copper crushing force, the steel pipe pile (A) is around 3.5kg / cm2 at -40 ° C, while the anti-frost pile (B) of the present invention is about 0.5 It was confirmed that it was kg / cm 2 and was particularly reduced.

In the above embodiment, the present invention is shown in the case of the steel pipe pile, but the present invention can also be carried out in concrete piles, plastic piles, and furthermore, in the conventional copper-sealing piles (for example, the increased strength of copper bond shown in Figure 3) It can be used together. In addition, the shape, material, etc. of each part are not limited to the above-mentioned embodiment, It can change suitably in the range which does not deviate from the summary of this invention. As apparent from the above description, the present invention has the following remarkable effects.

(1) Since the cohesion of the active layer with respect to the antibody can be greatly reduced, the structure in the cold region can be sufficiently protected from the East Sea.

(2) Since the cohesion force which acts on an antibody can be reduced, the depth of the part which gets into the ground of a pile can be shortened significantly. Furthermore, considering the construction performance, the cost can be greatly reduced.

(3) Since the fixed film was formed of a material having a small coefficient of friction on the surface of the antibody, there is little damage to the coating member and can withstand long-term use.

(4) In the case of the second invention, the length of the pile corresponding to the thickness of the active layer can be adjusted in addition to the effects of (1)-(3). The cost can be further reduced.

Claims (2)

In a pile of a type that reduces the crushing force and reverse friction acting on the pile in a cold region, the stretchable portion 12, (at least part of the antibody 1 formed by forming a solid film 1a on the surface in advance) 23), (24) and the cover member 11, (11a), (21) of the active layer (6) or the length of the seasonal frozen ground layer to cover the lower portion of the active layer (6) or seasonal frozen ground layer In the space below, and if necessary, the upper end portion is fixed to the antibody 1 above the surface of the earth so that a gas, a liquid, or the like is formed in the space formed by the solid coating 1a and the coating members 11, 11a, and 21. Donghae prevention pile, characterized in that the filling of the fluid material (17). In a pile of a type that reduces the alumni crushing force and reverse friction acting on the pile in a cold district, the antibody (1) formed by forming a solid film (1a) in advance on the surface having a length obtained by cutting several conventional piles The covering members 11, 11a, and 21 made of the stretchable parts 12, 23, and 24 are attenuated, and the upper and lower ends thereof are fixed inside the upper and lower ends of the antibody 1, and a solid film ( A pile member 30, 30a is formed by filling a fluid material 17 such as gas or liquid into a space formed by 1a and the covering members 11, 11a, and 21 to form the pile member ( 30), (30a) to prevent the East Sea, characterized in that the appropriate connection according to the thickness of the active layer (6) or seasonal frozen ground layer.

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