JP7342739B2 - How to reinforce an inverted T-shaped foundation - Google Patents

Description

The present invention relates to a method for reinforcing an inverted T-shaped foundation on which main leg members forming the legs of a structure such as a steel tower are installed.

In power transmission towers on which electric cables are stretched, the main legs that make up the legs are installed on the foundation. As the foundation, an inverted T-shaped foundation is often used, such as the foundation disclosed in Patent Document 1, for example. Patent Document 1 discloses a method for reinforcing steel tower legs. In the method for reinforcing a steel tower leg in Patent Document 1, the concrete of the foundation of the steel tower leg is scooped out, the exposed main column material is temporarily supported, and then the main column material is cut. Thereafter, a displacement adjustment fitting is attached to the cut location of the main pillar material, and the main pillar material is reconnected with the displacement adjustment fitting in a state where uneven displacement is alleviated. The exposed main pillars, including their displacement adjustment fittings, were then buried in concrete to rebuild the foundations of the legs.

Unexamined Japanese Patent Publication No. 2016-50450

The examination when designing a foundation is to examine whether the foundation can stably transmit the load to the ground (stability examination), and to check whether the load from the main leg of the steel tower is transmitted to the anchor material in the column and floor plate, It is broadly divided into examination of the inside of the foundation (structural examination) until the load is transferred to the ground. Depending on the direction of the wind acting on the steel tower, consideration must be given to ensuring that the tower can withstand both the load in the compression direction and the load in the lifting direction. The specific study methods for this stability study and structural study have changed depending on the year of construction, and the reality is that there is a mixture of designs based on old and new ideas.

If the structural and stability considerations are no longer met due to renovation of the tower equipment or review of the wind load design conditions, or if the strength of the tower section (above the foundation) is insufficient, it is possible to replace or strengthen only those parts. Existing steel towers can be reused. However, if the foundation lacks strength, reinforcement is not easy. In structural studies, if the foundation's bearing capacity is insufficient to withstand the lifting load, it is mainly necessary to make the columns thicker. In stability studies, if the bearing capacity of the foundation is insufficient, it is mainly necessary to make the floorboards larger (wider). However, with these methods, the reinforced foundation will be larger than the existing foundation, so it will be necessary to purchase additional land for the tower, or to secure construction land to dig a large area around the foundation. As a result, construction costs will increase. Additionally, since the foundation will become unstable during construction, it will be necessary to strengthen the foundation to stabilize it during construction.

In view of these issues, the present invention has developed an inverted T-shaped structure that allows the foundation to be reinforced within the site of the existing steel tower, reducing construction costs, and eliminating the need for foundation stabilization reinforcement during construction. The purpose is to provide a method for reinforcing foundations.

In order to solve the above problems, a typical configuration of the reinforcing method for an inverted T-shaped foundation according to the present invention is to install a new floor plate that extends laterally from the column at the upper end of the column of an existing inverted T-shaped foundation. The method is characterized in that the anchor reinforcing bars are fixed to the existing floorboards and the new floorboards of the existing inverted T-shaped foundation, and the existing floorboards and the new floorboards are connected by the anchor reinforcing bars placed on the outside of the column body.

According to the above configuration, the existing floor plate and the new floor plate are connected by the anchor reinforcing bar, so that the lifting load of the steel tower is transmitted to the new floor plate and then to the existing floor plate via the anchor reinforcing bar. Therefore, the lifting load transmitted from the existing main leg member to the existing floorboard is reduced. This will enable structural reinforcement of the existing tower foundation. Therefore, it is possible to reduce construction costs while reinforcing the foundation within the site of the existing steel tower and improving the strength of the foundation.

The anchor reinforcing bars may be inserted into the ground by penetrating the existing floorboards. According to this configuration, the lifting support capacity of the inverted T-shaped foundation can be increased, and the stability with respect to the ground can be improved.

It is preferable to attach an anchor material to the main leg material installed on the above-mentioned inverted T-shaped foundation column, and form a new floorboard so as to include the anchor material. This makes it possible to better fix the main landing gear to the new floorboard.

According to the present invention, it is possible to provide a method for reinforcing an inverted T-shaped foundation, which can reinforce the foundation within the site of an existing steel tower and can reduce construction costs.

It is a figure explaining the reinforcement method of the inverted T-shaped foundation concerning this embodiment. It is a figure explaining the process of the reinforcement method of the inverted T-shaped foundation concerning this embodiment. It is a figure showing other examples of the steel tower foundation of this embodiment. It is a figure showing other examples of the steel tower foundation of this embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in these embodiments are merely illustrative to facilitate understanding of the invention, and do not limit the invention unless otherwise specified. In this specification and the drawings, elements having substantially the same functions and configurations are designated by the same reference numerals to omit redundant explanation, and elements not directly related to the present invention are omitted from illustration. do.

FIG. 1 is a diagram illustrating a method for reinforcing an inverted T-shaped foundation (hereinafter referred to as a reinforcing method) according to this embodiment. FIG. 1(a) shows the steel tower foundation 100 observed from the side after it has been reinforced by the reinforcement method of this embodiment, and FIG. 1(b) shows the state after it has been reinforced by the reinforcement method of this embodiment. A steel tower foundation 100 is shown observed from above. As shown in FIG. 1, among the steel tower foundations 100, the existing foundation 110 provided when constructing the steel tower is an inverted T-shaped foundation.

FIG. 2 is a diagram illustrating the steps of the method for reinforcing an inverted T-shaped foundation according to this embodiment. As shown in FIG. 2(a), the existing foundation 110 includes a column 112 that supports the main leg member 102 that constitutes the leg of the steel tower, and a floor plate (hereinafter referred to as the existing floor plate 114) disposed at the lower end of the column 112. ). An anchor member 104 is attached to the lower end of the main leg member 102. Thereby, the main leg member 102 is fixed to the existing floorboard 114.

In the reinforcement method of this embodiment, first, the upper end of the column 112 of the existing foundation 110 shown in FIG. 2(b) is removed to expose the main reinforcement of the RC structure. Then, the area around the upper end of the column 112 is excavated. As a result, an excavated hole 120a for the newly installed floorboard is formed. Thereafter, as shown in FIG. 2(c), an insertion hole 130 is formed by drilling the outside of the column 112 from ground level to the existing floorboard 114.

As shown in FIG. 2(d), the anchor reinforcing bar 150 is inserted into the insertion hole 130. At this time, since the insertion hole 130 is formed by drilling up to the existing floorboard 114, the lower end of the anchor reinforcing bar 150 will be located inside the existing floorboard 114. On the other hand, the upper end of the anchor reinforcing bar 150 is located inside the excavated hole 120a. Knots are provided at the upper and lower ends of the anchor reinforcing bars 150 to increase the anchoring force to the existing floorboards 114 and the new floorboards 120. After inserting the anchor reinforcing bar 150, the insertion hole 130 is filled with grout 160 to fill the gap between the anchor reinforcing bar 150 and the insertion hole 130. As a result, the anchor reinforcing bars 150 are fixed to the existing floorboard 114.

Then, as shown in FIG. 2(e), form reinforcing bars 140 for the new floorboard are assembled in the excavated hole 120a. The formwork reinforcing bars 140 are connected to the main bars of the existing columns. A formwork for the new floorboard 120 is installed around the excavated hole 120a. In this embodiment, the formwork reinforcing bars 140 are installed after the anchor reinforcing bars 150 are installed, but these may be done in the reverse order.

Next, by pouring concrete into the excavated hole 120a, a new floor plate 120 is formed at the upper end of the column 112, extending laterally from the column 112, as shown in FIG. 2(f). The anchor reinforcing bars 150 are then fixed to the newly installed floorboard 120. As a result, the existing floorboard 114 and the new floorboard 120 are connected by the anchor reinforcing bars 150 placed on the outside of the column 112.

According to the reinforcement method of this embodiment, the existing floor plate 114 and the new floor plate 120 are connected by the anchor reinforcing bars 150, so that the lifting load of the steel tower is transmitted to the anchor material 104 and then transferred to the new floor plate 114 via the column body 112. The signal is transmitted to the floorboard 120. Therefore, the lifting load of the steel tower is transmitted to the existing floor plate 114 in a dispersed manner by the anchor reinforcing bars 150 and the anchor materials 104. Thereby, the existing floorboard 114 can be structurally reinforced without increasing its size. Moreover, since the new floor board 120 does not need to receive all the lifting load, the new floor board 120 may be small. Therefore, it is possible to reduce construction costs while reinforcing the foundation within the site of the existing steel tower and improving the strength of the foundation.

Although FIGS. 1 and 2 show four anchor reinforcing bars 150 evenly provided, the number and arrangement are merely examples, and can be increased or decreased as appropriate to satisfy structural considerations. The angle of the anchor reinforcing bars 150 is preferably parallel to the main leg member 102, but it does not need to be strictly parallel, as long as it can connect the existing floorboard 114 and the new floorboard 120 while avoiding the pillars 112.

3 and 4 are diagrams showing other examples of the steel tower foundation of this embodiment. In the steel tower 100a shown in FIG. 3, the anchor reinforcing bars 150 penetrate the existing floorboard 114 and are inserted into the ground 108. This makes it possible to increase the lifting strength of the steel tower foundation 100b (inverted T-shaped foundation), and to improve the stability with respect to the ground 108.

In addition, in the steel tower foundation 100b shown in FIG. 120 is formed. This makes it possible to better fix the load from the main leg member 102 to the newly installed floorboard 120.

Further, in the steel tower foundation 100c shown in FIG. 4(b), a bearing plate 106 is attached to the main leg member 102 inside the new floor plate 120, and a plurality of anchor reinforcing bars 150 are restrained by restraining reinforcing bars 170. This makes it possible to increase the fixing strength between the newly installed floorboard 120 and the main leg member 102.

Although preferred embodiments of the present invention have been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to such examples. It is clear that those skilled in the art can come up with various changes and modifications within the scope of the claims, and these naturally fall within the technical scope of the present invention. Understood.

INDUSTRIAL APPLICATION This invention can be utilized as the main leg material installation method of the deep foundation which installs the main leg material which comprises the leg part of structures, such as a steel tower, on a deep foundation foundation.

100... Steel tower foundation, 102... Main leg material, 104... Anchor material, 106... Bearing plate, 108... Ground, 110... Existing foundation, 112... Column body, 114... Existing floor plate, 120... New floor plate, 120a... Excavation hole, 130... Insertion hole, 140... Formwork reinforcing bar, 150... Anchor reinforcing bar, 160... Grout, 170... Restraining reinforcing bar

Claims (3)

A new floor plate is formed on the upper end of the column of the existing inverted T-shaped foundation and extends laterally from the column,
Anchor reinforcing bars are fixed to the existing floorboards of the existing inverted T-shaped foundation and the new floorboards,
A method for reinforcing an inverted T-shaped foundation, characterized in that the existing floorboard and the new floorboard are connected by the anchor reinforcing bars placed on the outside of the column. 2. The method for reinforcing an inverted T-shaped foundation according to claim 1, wherein the anchor reinforcing bars are inserted into the ground by penetrating the existing floorboard. Attach an anchor material to the main leg material installed on the inverted T-shaped foundation column,
3. The method for reinforcing an inverted T-shaped foundation according to claim 1 or 2, comprising forming a new floorboard so as to include the anchor material.

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