JPH07292663A - Additional driving construction and method by new steel-pipe pile making use of existing steel-pipe pile - Google Patents

Abstract

PURPOSE:To reduce cost for additional driving of a new steel-pipe pile by inserting the new steel-pipe pile having an outside diameter smaller than an inside diameter thereof in the existing steel-pipe pile. CONSTITUTION:A building 3 and foundation slabs 2 are demolished and removed, and cleaning such as elimination of foreign matters, etc., in the existing steel- pipe pile 1, elimination of corroded part in the upper part of the steel-pipe pile 1 and corrosion resisting treatment, etc., are performed. Then, after the bottom of the steel-pipe pile 1 is filled with high strength mortar 4, a new steel-pipe pile 10 having an outside diameter smaller than an inside diameter of the steel-pipe pile 1 is suspended from the top thereof, and the mortar 4 is pushed up to the lower bottom 3 of the steel-pipe pile 1 to drive additionally the steel-pipe pile 10. After that, corrosion resisting treatment is applied to pile heads of the steel-pipe pile 10 and steel-pipe pile 1, foundation slab concrete is placed, and the building 3 is constructed thereon. According to the constitution, there is no need to remove the steel-pipe pile 1, so that man-power, equipments and construction period for that purpose are not required, and cost can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for adding a new steel pipe pile using an existing steel pipe pile, and relates to a construction method and an additional structure for adding a new steel pipe pile without removing the existing steel pipe pile.

[0002]

2. Description of the Related Art Structures such as civil engineering buildings constructed on a foundation, for example, when the scale of an existing thermal power plant is expanded or refurbished, the structure building is increased. Construction work has been carried out such as removing the corroded parts of the existing steel pipe piles and renewing them. However, a turbine building of a thermal power plant (for example, one unit has a depth of 40 m and a length of 110
For buildings such as m, height of 50 m), a huge number of existing steel pipe piles (for example, steel pipe piles having a diameter of 600 mm are 350).
It is used (0 or more), and dismantling and removing it requires a great deal of labor and time.

[0003]

As a result of earnest research to solve the above-mentioned problems, the present inventor has developed a technique capable of adding a new steel pipe pile without removing the existing steel pipe pile. That is, the present invention provides (1) an additional steel pipe pile using an existing steel pipe pile, characterized in that a new steel pipe pile having an outer diameter smaller than the inner diameter of the same is inserted into the existing steel pipe pile, and (2) A new steel pipe pile using an existing steel pipe pile, which is characterized in that a new steel pipe pile having an outer diameter smaller than the inner diameter of the same steel pipe is inserted into the existing steel pipe pile. In the construction method of the present invention, particularly, the first step of disassembling / removing the structure and the basic concrete on the existing steel pipe pile, the treatment of corroded parts of the existing steel pipe pile, and the cleaning treatment of the existing steel pipe pile such as foreign matter removal It is preferable to adopt the third step of inserting a new steel pipe pile having an outer diameter smaller than the inner diameter of the existing steel pipe pile into the existing steel pipe pile that has been subjected to the cleaning treatment. Further, between the second step of cleaning the existing steel pipe pile and the third step of inserting the new steel pipe pile, a process of adding high-strength mortar to the inner bottom of the cleaned steel pipe pile is added. Is also preferable. Furthermore, in the above, it is also preferable to fill the gap between the existing steel pipe pile and the new steel pipe pile with high-strength mortar to increase the strength of the steel pipe wall.

[0004]

In the present invention, since a new steel pipe pile having an outer diameter smaller than the inner diameter of the existing steel pipe pile is inserted into the existing steel pipe pile, it is not necessary to remove the existing steel pipe pile. It becomes unnecessary. Further, there is no need to newly drill a hole for burying a steel pipe pile, and the cost can be significantly reduced.

[0005]

Embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional view for explaining a foundation portion of a thermal power plant, and FIG. 2 is an additional construction explanatory view using an existing steel pipe pile according to an embodiment of the present invention. As shown in FIG. 1, a thermal power plant building 3 is built on a foundation plate 2 supported by (existing) steel pipe piles 1. In carrying out the present invention, FIG.
As shown in (1), first of all, the building 3 and the foundation plate 2 are dismantled and removed in order to restore the deteriorated thermal power plant building 3 and to repair and strengthen the foundation accompanying the scale expansion. At this time, existing steel pipe piles (for example, outer diameter 600 mm, steel plate thickness 12 mm) 1
Cleaning such as removal of foreign matter inside, removal of corroded portions on the top of the steel pipe pile 1 and rust prevention treatment are also performed. Then, as shown in FIG.
After filling the bottom of the existing steel pipe pile 1 with high strength mortar 4,
A new steel pipe pile 10 having an outer diameter smaller than the inner diameter of the existing steel pipe pile 1 (for example, outer diameter 450 mm, steel plate thickness 9 mm) 10 is hung and inserted from above the existing steel pipe pile 1. The suspension insertion of the new steel pipe pile 10 is performed as shown in FIG.
The high-strength mortar 4 is pressed into the bottom of In addition,
Further, the gap (for example, 75 mm) 5 between the existing steel pipe pile 1 and the new steel pipe pile 10 may be filled with the high-strength mortar 4 to further increase the strength of the steel pipe pile. After that, new steel pipe pile 1
No. 0 and the existing steel pipe pile 1 are subjected to rust prevention treatment, the foundation concrete is placed, and the building 3 is built on it.

[0006]

As described above, according to the present invention, it is possible to easily achieve the required design pile supporting force against the expansion and modification of the structure on the foundation and the reduction of the proof strength due to the corrosion of the existing steel pipe pile. Construction is possible simply by inserting a new steel pipe pile into the existing steel pipe pile by hanging it or the like. Moreover, since it is not necessary to newly drill a pile hole, the excavation cost is almost unnecessary. Furthermore, the cost and construction period required for dismantling and removing existing steel pipe piles can be greatly reduced. Further, when the steel pipe pile is removed, a ground collapse prevention measure around the hollow portion after the removal is required, but such a measure is not required according to the present invention.

[Brief description of drawings]

FIG. 1 is a sectional view illustrating a basic portion of a thermal power plant.

FIG. 2 is an additional construction explanatory diagram using an existing steel pipe pile according to an embodiment of the present invention.

[Explanation of symbols]

 1: Existing steel pipe pile, 2: Foundation version, 3: Thermal power plant building, 4: High strength mortar, 5: Gap, 10: New steel pipe pile

Claims (5)

[Claims] A new steel pipe pile using an existing steel pipe pile, characterized in that a new steel pipe pile having an outer diameter smaller than the inner diameter of the pile is inserted into the existing steel pipe pile. 2. A reinforcement method using a new steel pipe pile using an existing steel pipe pile, wherein a new steel pipe pile having an outer diameter smaller than the inner diameter of the same is inserted into the existing steel pipe pile. 3. A first step of disassembling / removing a structure and a foundation concrete on an existing steel pipe pile, a corrosive treatment of the existing steel pipe pile, a second process of cleaning the existing steel pipe pile such as foreign matter removal, and a cleaning treatment. And a third step of inserting a new steel pipe pile having an outer diameter smaller than the inner diameter of the existing steel pipe pile into the already existing steel pipe pile. 4. A step of introducing high-strength mortar into the inner bottom of the cleaned steel pipe pile between the second step of cleaning the existing steel pipe pile and the third step of inserting the new steel pipe pile. The additional construction method using a new pile using the existing steel pipe pile according to claim 3, wherein the steel pipe pile is added. 5. The additional pile construction method using a new pile using an existing steel pipe pile according to claim 2, wherein a high-strength mortar is filled in a gap between the existing steel pipe pile and the new steel pipe pile. .