JPS6241819A - Pile with taking-out lubrication layer - Google Patents

Abstract

PURPOSE:To enable a pile to be taken out by the force of a usual winch, by coating the surface of the pile, with a re-wetting lubrication layer with water absorbing polymer and re-wetting binder mixed together and dried and solidified. CONSTITUTION:When a pile 1 is cast in the cement layer 8 of cement mil, then the water content of the cement layer 8 is absorbed by water absorbing polymer 5 and re-wetting binder 6. After that, the thickness of a re-wetting lubrication layer 2 is increased, and the non-solidified cement layer 8 is removed from the surface of the pile 1. In the expanded re-wetting lubrication layer 2, the water absorbing polymer 5 is turned into a large or small rolling ball, and the re-wetting binder 6 is gelatinized or sludge-formed to play a part of lubricant. As a result, the pile can be easily taken out, and the pile can be used,no as a throwaway article but as a recovery article.

Description

[Detailed Description of the Invention] Industrial Field of Application The present invention is characterized in that when the cement I layer is driven, the re-i□! The present invention relates to a pile with a lubricant layer for pulling out that can be easily pulled out when the pile is to be recovered after being used as a parent pile because the d-type lubricant layer absorbs water and forms a lubricant surface.

Conventional technology Drill continuous rows of holes in the ground using an earth auger, press-fit cement mixed with bentonite, etc. into the holes, and insert I-I type steel piles at important points in the holes. Insert L2 into the column earth retaining wall into the groove [iZL~, ground 2 I- surrounded by the earth retaining wall.
When a basement or the like of a building is constructed in the box-shaped pilot hole formed by this, the earth retaining wall used when forming the pilot hole becomes obsolete. Precautions: The FI type steel used as the main pile for the earth retaining wall is long and relatively expensive, so it should be collected, or it is hard to pull out because it is hard-wired into the cement layer, so it is left unattended. There is. At present, attempts are being made to apply grease to the desk surface in advance as a means of collecting the piles, and then to pull the piles out with a special pile removal device after they have been used. Since it is removed from the surface, it is difficult to retain the required amount of grease, and it is not functionally sufficient as a lubricating surface, so it is still difficult to pull out, and special strong equipment is required.

Problems to be Solved by the Invention The present invention provides a method for retrieving piles driven into a cement layer by forming a good lubrication direction between the cement layer and the desk surface.
The pile can be pulled out with the power of a normal hoist equipped with an earth auger, etc., and it also has a lubricating layer for pulling out that makes it easy to set a lubricating surface on the pile surface and manage the pile in the air with any direction of lubrication. Aim to get a pile.

Means for Solving the Problem The present invention provides a pile with a sliding layer for a desk surface as a means for solving the problem. The water-absorbing polymer is a highly water-absorbing polymer that is insoluble in water and absorbs hundreds of times its own weight in water to swell and form a hydrogel. For example, acrylic acid copolymers (crosslinked polyacrylic acid, starch-based rP'J7 Glyric acid copolymerized acids, etc. polymers, acrylic acid vinyl alcohol copolymer, crosslinked polyethylene oxide, crosslinked carboxylmethylated cellulose sodium salt or calcium salt, etc. The rewetting binder is a binder that can be made into a solid by drying. However, when it absorbs water, it becomes paste-like, mud-like, agar-like, etc., such as starch paste, polyvinyl alcohol-based paste, etc., and it is desirable that it can be solidified into a film and has some elasticity.

Operation The operation of the present invention is shown in FIG. When the pile 1 is put into the cement layer 8 made of cement milk, the water-absorbing polymer 5 and the rewetting binder 6 absorb the moisture in the cement layer 8. In this case, the water-absorbing polymer 5 swells into large and small spheres by absorbing water, and the rewetting binder 6, if it is a sizing agent, softens into a paste-like state by absorbing water. The rewetting lubricant layer 2 then increases in thickness and eliminates the unsolidified cement layer 8 from the surface of the pile l. After this, the cement layer 8 is solidified. It is not preferable that the thickness of the rewetting layer 2 when swollen is too large. At this thickness of 1 year, which is enough to prevent it from rattling inside the pile hole in the solidified cement layer, the water-absorbing polymer 5 becomes large and small rolling balls, and the rewetting binder 6 gelatinizes and becomes muddy. Acting as a lubricant, a very slippery, lubricating edge surface is formed between the cement layer and the desk surface. Therefore, the pile can be easily pulled out by lifting the pile cap with the same crane used to insert the pile.

Embodiment 1 Embodiment 1 of the present invention will be explained with reference to FIGS. 1 to 3. l is an H-shaped steel pile with a total length of approximately 5 m and a cross section with a flange length of 1
5c+y+, the web length is 30 cm, the thickness is 0.7 G, and the weight is about 1 fi 5 Ky. 2 is a rewetting lubricant layer placed on the surface of the 7 lunges 3 and web 4, excluding the head of pile 1, and 1 starch sugar for corrugated board is used as a rewetting binder.
00 parts, 30 parts of Sumikagel 5P-510 (manufactured by Sumika Kagaku), a trade name made of vinyl acrylate alcohol copolymer as a water-absorbing polymer, was added with an appropriate amount of water and kneaded into a paste, and this paste was mixed with the above-mentioned It was applied to a desk surface, dried and solidified to form a 100μ thick layer. In Fig. 3, 7 is a protective layer coated on the rewettable lubricant layer 2, which is a nonwoven fabric made of polyvinyl alcohol binder type and placed on the same layer while the rewettable lubricant layer 2 has adhesive strength. , which is mainly composed of polyester. Although this nonwoven fabric may be omitted, the mechanical strength of the rewettable lubricant layer 2 is maintained, and the water permeability to the rewettable lubricant layer 2 is controlled by the amount of polyvinyl alcohol and the density of the cloth.

When using the above piles, first inject cement milk mixed with tonite, excavated earth and sand, water, etc. as shown in Figure 4.
The upper ends of the piles were assembled and suspended using the wire of the hoisting machine fed out from the league mast of the earth auger, and the piles were inserted into a part of the continuous row holes 9. After the cement milk has solidified and the column walls of the cement layer 8 have been completed, that is, 10 days later, when the top end of the pile is secured with the wire mentioned above and the pile is pulled up, a slight traction force is added to the pile's own weight. I was able to pull out the stake. Conder 6 gelatinizes and pushes the cement milk away from the desk surface.
This is presumed to be because the cement layer 8 maintains its water absorption state even after solidification, thereby maintaining a good edge-cut lubricating layer between the cement layer 8 and the desk surface. It is thought that this lubricating layer becomes thinner at the bottom of the pile due to Tonosho, but the lubricity was completely maintained when the pile was pulled out. Then, one month later, due to continuous sunny weather, no moisture entered the rewetting lubricant layer 2, the cement layer dried, and the water-absorbing polymer 5
The moisture in the re-wetted V1 Mibainter'-6 escaped and the whole was reduced to a skeleton shape, but the voids in the lubricating layer during swelling were maintained between the cement layer 8 and the desk surface. Therefore, when one end of the pile-1 was struck to completely destroy the skeletonized rewetting lubricant layer, the pile was easily pulled out.

Note that the rewetting lubricant layer 2 may be provided under the thin insulation layer 7 and formed into a sheet, and an adhesive may be applied under the rewetting lubricant layer 2 or on the anti-layer to adhere it to the desk surface. If a silicone resin-based adhesive is used as the adhesive, it will be easier to remove the deposits remaining on the desk surface after the pile is pulled out.

Embodiment 2 Embodiment 2 of the present invention will be explained with reference to FIG. 12 is an iron pipe, and 10 is a rewetting lubricating layer provided on the pipe surface. This rewetting lubricant layer is made by adding moisture to 100 parts of polyvinyl alcohol rewetting glue as a rewetting binder and 20 parts of Wonder Zeel (manufactured by Kao Soap Co., Ltd.), a trade name made of an acrylic acid copolymer, as a water-absorbing polymer. A kneaded material is prepared, and this is applied to the surface of the pipe 12 and dried and solidified.
The layer is 0()μ thick. 11 is a rewetting layer lO
Kraft paper (sop/m) was used, with a coating layer that had a sticky appearance on the layer when solidified.

This pipe 12 with a rewetting lubricant layer is set together with a formwork in a transverse state penetrating the earth retaining wall of the land being created, and when the pipe is pulled out after the cement has hardened, the pipe can be easily pulled out due to the lubricity of the rewettable lubricant layer 10. We were able to drain the water and create a good drainage hole on the wall where the pipe remained.

Effects of the Invention In the present invention, a rewetting lubricant layer that absorbs water and becomes a lubricant layer is provided on the desk surface in an assimilated state, so it does not peel off or drip while handling the pile in the air. After absorbing water, the water-absorbing polymer swells into a spherical shape and becomes a trochanter, and the rewetting binder gelatinizes and becomes slurry, turning into a lubricating oil. This makes it easier to pull out the piles, and the piles can be used as recovered materials rather than as materials for hammering and inspection, making construction costs economical.

[Brief explanation of the drawing]

Fig. 1 is a front view of Embodiment 1 of the present invention, Fig. 2 is an enlarged sectional view taken along line A-A of Embodiment 1, Fig. 3 is an enlarged sectional view of main parts of Embodiment 1, and Fig. 4 is A top view of a pillar-row earth retaining wall where Example 1 is used, FIG. 5 is an enlarged sectional view of the main part showing the effect of Example 1, and FIG. 0 is Example 26...rewetting binder.

Claims (1)

[Claims] A pile with a lubricant layer for extraction, which is coated on the pile surface with a rewetting lubricant layer made by kneading a water-absorbing polymer and a rewetting binder and drying and solidifying it.