JPH1077645A - Foundation reinforcing construction method for cylindrical tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To execute work at low a cost with high efficiency by moving a ground improvement machine around a tank without transferring piping or the like in a tank yard prior to constructing a ring-shaped setting wall in a surrounding area for an oil tank or the like constructed under Fire Service Law legislated before 1977. SOLUTION: According to this foundation reinforcing construction method for a cylindrical tank, a rail 2 is provided in the outer peripheral area of a side plate 1' of a cylindrical tank 1 prior to constructing a ring-shaped setting wall as a means designed to troubleshoot the liquefaction trouble of a surrounding ground of an existing cylindrical tank and a part 20 of a ground improvement machine 10 is remodeled so that the ground improvement machine 10 may move along this rail 2. It is also possible to provide the rail on a crushed stone in the surrounding area of the side plate 1' of the cylindrical tank 1 by way of a support member.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of reinforcing a foundation for a cylindrical tank, and more particularly, to liquefaction for repairing and reinforcing the foundation of an existing cylindrical tank such as an oil tank using a ground improvement machine. Concerning the construction method to be used for countermeasures.

[0002]

2. Description of the Related Art The safety evaluation standards for oil tanks mainly for liquefaction of the ground during an earthquake are amended by the Fire Service Law (July 1995).
Oil tanks built under the old law (hereinafter referred to as the "old law tanks") as a result of the lifting
In some cases, liquefaction countermeasures are required, and various construction methods are currently being studied.

As one mode of liquefaction countermeasures for an old tank, as shown in FIG. 4, a ring-shaped solidified wall 40 is constructed around the tank 1 to liquefy the ground inside the solidified wall 40 during an earthquake. It has been proposed to reduce settlement by excavating the ground with a soil improvement machine and replacing it with solidified material, or by injecting solidified material to build a solidified wall, This is performed all around the tank while moving.

[0004]

However, since pipes are complicated in the tank yard and various peripheral equipment for tanks exist, it is necessary to run and move the ground improvement machine around the tank. In such a case, it is necessary to relocate piping and the like, and in this case, the construction cost increases and the work becomes inefficient.

Accordingly, an object of the present invention is to construct a ring-shaped solidified wall on the surrounding ground of an old tank or the like, and to move a ground improvement machine around the tank without moving piping or the like in a tank yard. Accordingly, an object of the present invention is to provide a method for reinforcing a foundation of a cylindrical tank, which can make the work inexpensive and efficient.

[0006]

According to the method for reinforcing a foundation of a cylindrical tank according to the present invention, a ring-shaped solidified wall is constructed on the ground around an existing cylindrical tank as a countermeasure against liquefaction. A track is provided on the outer periphery, and the ground improvement machine is moved along the track.

Here, the existing cylindrical tank is mainly an old tank, but is not particularly limited to this.
Further, the track can be installed so as to bypass an obstacle such as a tank peripheral device.

As the method of the track structure, known ones such as a rail roller type, a rack and pinion type, a chain block and a sprocket type can be used. Modifications such as installation of rollers, pinions, sprockets, etc. on a part of the ground improvement machine will be performed so that the ground improvement machine can move along the track while being installed on the outer peripheral surface. As a result, the ground improvement machine can move around the tank in a state of floating above the ground surface without passing through a traveling device including tracks or tires.

[0009] Although the entire weight of the ground improvement machine can be borne by the cylindrical tank via the track, most or a part of the weight can be borne by the crane via the wire.

As the ground improvement machine, known machines such as a boring machine and various dedicated machines for high-pressure injection / injection can be used, and a compact and relatively lightweight construction machine having good stability can be used. Especially desirable.

Another aspect of the present invention is to provide a track on a foundation around a side plate via a support member. Here, on the foundation around the side plate is generally on the ground surface outside the dog running part and the RC ring. Further, the support member is a scaffold plate or the like interposed for installing the track so as to float above the ground surface.

[0012]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows an old tank 1 as a cylindrical tank.
It is explanatory drawing which shows roughly the example which provided two rails 2 as a track | truck on the outer peripheral surface of the side plate 1 '. A compact boring machine was used as the ground improvement machine 10. This ground improvement machine 10 is a well-known machine, and therefore will not be described in detail.
It is moved by a slide mechanism (not shown).

Each of the rails 2 has a T-shaped cross section, and is installed up and down with respect to the tank side plate 1 'via a rail sheet 3 having a U-shaped cross section. On the other hand, the ground improvement machine 10 has a modified portion 20 so that it can be moved along the rail 2.
The modified portion 20 includes an upper roller 21 mounted on the upper side surface of the upper rail 2, and a lower roller 22 that presses and contacts the top surface of the lower rail 2.

The solidified wall 40 around the old tank 1 (see FIG. 4) is constructed by providing a plurality of solidified solid bodies 40 ′ over the entire circumference of the tank 1 while partially overlapping each other.
Each solidified body 40 'is drilled to a predetermined depth while rotating and descending the drill pipe 14 of the ground improvement machine 10 at one point, and the ground excavated when the drill pipe 14 is lifted is replaced with solidified material. Formed. When the boring machine 10 is moved to the next point, the boring machine 10 is guided to the rail 2 from the rollers 21 and 22. This movement may be manual or mechanical.

FIG. 2 is an explanatory view schematically showing an example in which a rail 32 is provided via a support member on a dog running portion 6 on a crushed stone ring 4 which is a foundation on a peripheral portion of a side plate 1 ′ of an old method tank 1. It is.

The ground improvement machine is the same as that shown in FIG. 1 except for the remodeling part, and the same parts are denoted by the same reference numerals and description thereof will be omitted.

The rail 32 is an equilateral triangular steel, which comprises a jack 33 as a support member, an I-shaped steel 34, and a scaffold plate 3.
5. It is provided at a distance from the ground surface via the gantry 36. FIG. 3 is a plan view of the rail 32 and the support member, and the support member is installed while avoiding piping and tank peripheral devices.

Further, wheels are attached to the ground improvement machine 10 to be engaged with the rails 32.

Reference numeral 5 in FIG. 2 denotes an RC ring for supporting the crushed stone ring 4.

[0021]

In the method for reinforcing the foundation of a cylindrical tank according to the present invention, a track is provided on the outer periphery of a side plate of the cylindrical tank, and a ground improvement machine is moved along the track to construct a ring-shaped solidified wall. In doing so, there is no need to relocate piping and the like in the tank yard, and the work can be made inexpensive and efficient. The same effect can be obtained by providing the track on a foundation around the side plate of the cylindrical tank via a support member.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view showing an example in which a rail is provided on the outer periphery of a side plate of an old tank.

FIG. 2 is a schematic explanatory view showing an example in which a rail is provided via a support member on a peripheral portion of a side plate of an old tank.

FIG. 3 is a plan view of a rail and a support member of FIG. 2;

FIG. 4 is an explanatory view showing a state where a ring-shaped solidified wall is constructed on the ground around the old tank.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Old method tank 1 'Side plate 2, 32 rails 4 Crushed stone 10 Boring machine 20 Modification part 21 Upper roller 22 Lower roller 33 Jack 34 I-shaped steel 35 Scaffolding plate 36 Mounting base 40' (Cylindrical) solidified body 40 Solidified wall

Claims (2)

[Claims] When a ring-shaped solidified wall is constructed on the ground around an existing cylindrical tank as a measure against liquefaction, a track is provided on the outer periphery of a side plate of the cylindrical tank, and a ground improvement machine is moved along the track. A method for strengthening the foundation of a cylindrical tank, characterized by the following. 2. When a ring-shaped solidified wall is constructed on the ground around an existing cylindrical tank as a measure against liquefaction, a track is provided via a support member on a foundation around a side plate of the cylindrical tank. A method for strengthening the foundation of a cylindrical tank, characterized by moving a soil improvement machine along the ground.