JP2005076049A - Method for cathodically protecting foundation pile - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To adequately prevent the corrosion of a plurality of foundation piles P by adequately arranging an electrode HE, in a method for cathodically protecting the foundation piles P by passing a protection current from the electrode HE buried in a ground G to a plurality of the foundation piles P vertically driven into the ground G. <P>SOLUTION: The method for cathodically protecting the foundation piles by passing the protection current from the electrode buried in the ground G to a plurality of the foundation piles P vertically driven into the ground G includes arranging the electrode HE between the adjacent foundation piles P. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for cathodic protection of a foundation pile in which an anticorrosion current is applied from an electrode embedded in the ground to a plurality of foundation piles that are vertically penetrated into the ground.

  When building a foundation to support a structure, if the ground bearing capacity of the ground layer alone is not sufficient, a pile foundation in which a plurality of foundation piles are vertically penetrated into the ground may be constructed. Moreover, the group pile which consists of a some foundation pile may be used for the foundation for structures with a heavy weight like the storage tank installed outdoors.

  Foundation piles made of steel pipes need to be protected against corrosion. As a method of preventing corrosion of a group pile consisting of a plurality of foundation piles, an electrode is installed on the ground where the foundation pile penetrates, and a corrosion prevention current is passed from the electrode to the foundation pile via the ground, so that the corrosion potential of the foundation pile is reduced. An external power supply method (see, for example, Patent Document 1) for reducing the above can be adopted.

  Conventionally, in the above-mentioned method for cathodic protection of foundation piles, the electrodes are appropriately arranged so as to surround the foundation area where the group piles exist in the ground, and the anti-corrosion state of the foundation pile is confirmed by performing a temporary energization test. And had anti-corrosion.

Japanese Patent Laid-Open No. 9-272991

However, in the conventional anticorrosion method for foundation piles, the electrodes were appropriately placed around the foundation area, so they were placed in positions where other foundation piles existed between the electrodes in the center of the foundation area. There was a case where the anticorrosion current was not sufficiently applied to the foundation pile, and the anticorrosion was incomplete.
Accordingly, the present invention has been made in view of the above circumstances, and in the above-mentioned foundation pile electrocorrosion protection method, the electrodes are appropriately arranged to appropriately prevent corrosion of a plurality of foundation piles. The object is to simplify the electrode placement work as much as possible.

  In order to achieve this object, the first characteristic configuration of the method of cathodic protection of foundation piles according to the present invention is that a plurality of foundation piles vertically penetrated into the ground are subjected to a corrosion prevention current from electrodes embedded in the ground. It is an electrocorrosion protection method for a foundation pile to be energized, wherein the electrode is disposed between adjacent foundation piles.

  In other words, according to the method of cathodic protection of foundation piles of the first characteristic configuration, by arranging electrodes between adjacent foundation piles that are adjacent to each other, the electrodes are applied to each foundation pile. Thus, the anticorrosion current can be applied well, and the anticorrosion of a plurality of foundation piles can be appropriately performed.

  In addition to the first feature configuration described above, the second feature configuration of the foundation pile electro-corrosion protection method according to the present invention is configured so that the electrode passes between adjacent foundation piles that are configured by a long shaft body. It is in the point of penetration.

That is, according to the cathodic protection method of the foundation pile of the second feature configuration, the electrode is made of a long shaft body such as a tube or bar made of steel, magnetic iron oxide, or silicon cast iron, and the electrode is By penetrating so that it passes between adjacent piles in a direction that intersects the vertical direction, even if there are existing structures on the foundation piles, the center part from the outside where the structures do not get in the way Since it is only necessary to penetrate the electrode toward the end, it is possible to simplify the electrode penetration operation and improve workability.
In addition, by arranging the electrodes so that one electrode passes between adjacent foundation piles, the number of electrodes can be reduced as much as possible, and the work and equipment for performing the anticorrosion method for the foundation piles Simplification and cost reduction can be realized.

  In addition to the first to second feature configurations described above, the third feature configuration of the foundation pile electro-corrosion protection method according to the present invention is configured such that the electrode is formed of a long shaft body and is vertically disposed adjacent to the foundation pile. It is in the point of penetration.

That is, according to the anticorrosion method of the foundation pile of the third characteristic configuration, the electrode is made of a long shaft body, and the electrode is inserted into the foundation pile along the vertical direction between adjacent foundation piles. On the other hand, anticorrosion can be applied in the widest possible range in the depth direction (vertical direction).
In addition, when the long-axis electrode penetrates along the vertical direction between adjacent foundation piles, there is an appropriate space for the electrode penetration work between the ground and the structure. However, for example, by making the electrode a structure that can be divided into a plurality of nodes, even with electrodes that are longer than the height of the space above the ground, along the vertical direction between adjacent foundation piles Can penetrate.

  In addition to the first to third feature configurations described above, the fourth feature configuration of the foundation pile electro-corrosion protection method according to the present invention includes the other foundation piles between the electrodes in each of the plurality of foundation piles. It is in the point which arrange | positions the said electrode so that it may not exist.

  In other words, according to the method of cathodic protection of foundation piles of the fourth feature configuration, at least one electrode is disposed in the vicinity of each of the plurality of foundation piles, and no other foundation pile exists between the electrodes. As a result, the anticorrosion current can be passed through the electrodes satisfactorily from the electrodes without interfering with the other foundation piles, and the anticorrosion state of each foundation pile can be improved.

  In addition to the first to fourth feature configurations, the fifth feature configuration of the foundation pile electrocorrosion protection method according to the present invention is one for a plurality of columns or rows between which the plurality of foundation piles are arranged. It is in the point which arrange | positions the said electrode every other.

  That is, according to the method of cathodic protection of foundation piles of the fourth feature configuration, when arranged over a plurality of columns or rows of a plurality of foundation piles, with respect to the columns or rows of the respective foundation piles Since the electrodes HE need only exist on one side, it is possible to reduce the number of electrodes as much as possible by arranging every other electrode between the columns or rows.

Embodiments of the present invention will be described with reference to the drawings.
FIG.1 and FIG.2 is the perspective view and top view which show the mode of 1st Embodiment of the cathodic protection method of the foundation pile which concerns on this invention, FIG.3 and FIG.4 is the cathodic protection of the foundation pile which concerns on this invention It is the perspective view and top view which show the mode of 2nd Embodiment of a method.

As shown in FIGS. 1 to 4, a plurality of foundation piles P vertically penetrated into the ground G are for structures (not shown) such as tanks for storing gas or oil installed outdoors. It is constructed as the foundation of
Moreover, when such a foundation pile P is manufactured with the steel pipe, it is necessary to take anti-corrosion measures.

Therefore, in the first and second embodiments, each foundation pile P is subjected to cathodic protection by the external power supply method.
That is, in the ground G into which the foundation pile P has penetrated, electrodes HE and VE to which a potential difference is added between the foundation pile P and the ground pile P are embedded by the power source S, and the electrodes HE and VE pass through the ground G. By causing the anticorrosive current to flow through the foundation pile P, the corrosion potential of the foundation pile P is lowered, and the foundation pile P is electrically protected.

  Further, the electrodes HE and VE are arranged between a plurality of adjacent foundation piles so that the anticorrosion current can be applied to the foundation piles from the electrodes HE and VE. Located between adjacent foundation piles.

  Furthermore, in 1st Embodiment shown in FIG.1 and FIG.2, the electrode HE is produced with long axis bodies, such as pipes or rods, such as steel, magnetic iron oxide, or silicon cast iron, The long axis The body electrode HE penetrates from the outside of the plurality of foundation piles P so as to pass between adjacent foundation piles P along the horizontal direction. Thus, since electrode HE should just penetrate from the outside of a plurality of foundation piles P, even when a structure already exists on foundation pile P, foundation pile P and the structure on it do not get in the way, A relatively long electrode HE can be penetrated.

  Moreover, in order to energize the anticorrosion current to all the foundation piles P when arranging the electrodes HE between the rows of the foundation piles P for the plurality of foundation piles P arranged in a plurality of rows. Since the electrodes HE need only exist on one side with respect to the rows of the respective foundation piles P, the electrodes HE between the rows of the respective foundation piles P as shown by the solid lines in FIG. 1 and FIG. Thus, the electrodes HE may be arranged every other line, that is, between the rows.

  Furthermore, in the said 1st Embodiment, although the electrode HE of the long axis body penetrated so that it might pass along between the adjacent parts of the foundation pile P along the horizontal direction, the electrode HE of the long axis body was separately attached to the foundation pile. You may penetrate so that it may pass along the direction sloping with respect to the horizontal direction between adjacent P.

Furthermore, in 2nd Embodiment shown in FIG.3 and FIG.4, the electrode VE is produced with the long-axis body, and the electrode VE of the long-axis body has several axial piles between adjacent, and an axial center. It penetrates along the vertical direction (that is, parallel to the foundation pile P). In this way, by arranging the electrodes VE in parallel with the foundation piles P between adjacent ones of the plurality of foundation piles P, the anticorrosion current is as wide as possible in the depth direction (vertical direction) with respect to each foundation pile P. Can be energized to provide good corrosion protection.
In addition, since the electrode VE needs to penetrate the ground G in the space between the ground G and the structure on the foundation pile P, the length may be equal to or less than the height of the space. The electrode VE can be divided at a plurality of nodes, and even a relatively long electrode VE can penetrate the ground G.

  In addition, when the electrodes VE are arranged in an adjacent space surrounded by four foundation piles P adjacent to each other with respect to the plurality of foundation piles P arranged in a plurality of rows and columns, for all the foundation piles P In order to satisfactorily pass the anticorrosion current, it is sufficient that at least one electrode VE is disposed adjacent to each foundation pile P, so that the electrodes VE indicated by solid lines in FIGS. The electrodes VE may be arranged every other row, that is, between every row and every other row, between the rows and between the rows of the respective foundation piles P.

  Next, as a result of verifying whether the arrangement state of the electrodes HE and VE is capable of satisfactorily applying the anticorrosion current to each foundation pile P in the electrocorrosion prevention method of the foundation pile P described so far. Will be described.

  As a result of the simulation by the numerical analysis method using the conditions of the reduced model simulating the site where the foundation pile P is constructed and the environmental conditions such as soil properties and polarization behavior measured in advance in the field as input parameters, the first In any case, the method of cathodic protection of the foundation pile P according to the embodiment and the second embodiment could confirm that the foundation pile P group was totally catalyzed.

  In addition, when electrodes are placed only outside the foundation pile group as in the past, a large amount of anticorrosion current flows from the outermost part of the foundation pile group into the first layer foundation pile, Although it could be achieved, it was difficult to reach a corrosion protection current from the outermost layer to the inner side of the second layer, and it was confirmed by simulation by the above numerical analysis method that sufficient corrosion protection could not be achieved.

  When the foundation pile is provided with a standard for corrosion protection of several meters from the ground surface to be protected in the earthquake-resistant design, the corrosion prevention current can be adjusted based on the standard. If the above criteria cannot be satisfied only by adjusting the anticorrosion current, the position, shape, and dimensions of the electrode are set again, and simulation by numerical analysis is performed again to verify the anticorrosion effect. Do.

  Moreover, the electrode HE of the long-axis body which passes between adjacent of the foundation pile P as demonstrated in the said 1st Embodiment along a horizontal direction, for example, and the adjacent of the foundation pile P as demonstrated in the said 2nd Embodiment A long-axis electrode VE that penetrates along the vertical direction may be combined and constructed, for example, for a foundation pile P that needs to be protected extensively along the depth direction. The electrodes HE and VE are arranged so that the electrode VE penetrates along the vertical direction between the adjacent ones and the electrode HE passes between the adjacent piles P along the horizontal direction along the horizontal direction. can do.

The perspective view which shows the mode of 1st Embodiment of the cathodic protection method of the foundation pile which concerns on this invention. The top view which shows the mode of 1st Embodiment of the cathodic protection method of the foundation pile which concerns on this invention The perspective view which shows the mode of 2nd Embodiment of the cathodic protection method of the foundation pile which concerns on this invention. The top view which shows the mode of 2nd Embodiment of the cathodic protection method of the foundation pile which concerns on this invention

Explanation of symbols

G: Ground P: Foundation pile S: Power HE, VE: Electrode

Claims (5)

For a plurality of foundation piles penetrating vertically into the ground, it is an electrocorrosion protection method for foundation piles in which an anticorrosion current is passed from an electrode embedded in the ground,
An anticorrosion method for a foundation pile in which the electrode is disposed between adjacent foundation piles.   The method of cathodic protection of a foundation pile according to claim 1, wherein the electrode is penetrated so as to pass between adjacent foundation piles that are constituted by a long shaft body.   The method of cathodic protection of a foundation pile according to claim 1, wherein the electrode is constituted by a long shaft body and penetrates vertically between adjacent foundation piles.   The method of cathodic protection of a foundation pile according to any one of claims 1 to 3, wherein in each of the plurality of foundation piles, the electrodes are arranged such that no other foundation pile exists between the electrodes. .   The method of cathodic protection of foundation piles according to any one of claims 1 to 4, wherein every other electrode is arranged between a plurality of columns or rows between which the plurality of foundation piles are arranged.

Images