JP6302222B2 - Horizontal force support structure and method for constructing horizontal force support structure - Google Patents

Description

  The present invention relates to a horizontal force support structure which is an earthquake countermeasure work during seismic isolation repair work for an existing building and a method for constructing a horizontal force support structure.

For the purpose of seismic isolation of existing buildings, seismic isolation devices may be installed between the superstructure and the foundation structure. The seismic isolation existing building can reduce the horizontal force at the time of earthquake input to the superstructure, and avoid the resonance phenomenon by making the natural period of the superstructure longer.
For such a seismic isolation device, for example, a laminated rubber or a sliding bearing is adopted.

  Seismic isolation repair work for existing buildings involves excavating below the existing building, forming a foundation slab below the existing building, and supporting the existing building with the support provided on the foundation slab. (See Patent Document 1).

During seismic isolation repair of existing buildings, it is desirable to provide a horizontal force support structure in case an earthquake occurs.
As the horizontal force support structure, for example, a beam is installed between an existing building and a surrounding retaining wall, or between the upper structure and the surrounding retaining wall as shown in Patent Document 2. There are some that lay a temporary slab horizontally.

Japanese Patent No. 2819008 Japanese Patent No. 4228257

  Since the conventional horizontal force support structure needs to be removed entirely after the repair work is completed, it takes time and effort for the removal work and costs for disposal.

  In addition, when a beam is used as the horizontal force support structure, the retaining wall will be constructed until the existing building is fully seismically isolated in order to build a retaining wall around the existing building after the beam is removed. It was not possible to start, and it was an obstacle to shortening the construction period.

  In addition, when temporary slabs are used, anchors for fixing the temporary slabs need to be embedded in the retaining walls around the existing building, so it is necessary to construct the retaining walls in advance, which hinders shortening the construction period. There was a case.

  From such a viewpoint, it is an object of the present invention to propose a horizontal force support structure and a method of constructing a horizontal force support structure that can be easily and inexpensively constructed and that can shorten the work period. To do.

In order to solve the above-mentioned problems, the present invention provides a horizontal force support structure for supporting an existing building under seismic isolation repair work, a mountain retaining wall formed around the existing building, and the mountain retaining wall. A support member installed between the existing buildings, and the support member constitutes a part of a retaining wall constructed along the mountain retaining wall and passes through the reinforcing bar of the retaining wall It is characterized by having a precast concrete plate in which a plurality of through-holes are formed .

According to such a horizontal force support structure, since the support member constitutes a part of the retaining wall, it becomes possible to perform the retaining wall construction in parallel with the seismic isolation work of the existing building. Shortening is possible.
Moreover, the labor required for removing the support member can be reduced.

It said support member, since it has a plurality of through holes precast concrete panel, which is formed Rebar be for insertion of the retaining wall, workability is further improved.

  Further, the construction method of the horizontal force support structure of the present invention includes a mountain retaining step for forming a mountain retaining wall along the outer surface of an existing building, and a drilling step for excavating between the mountain retaining wall and the existing building, An installation step of installing a support member between the mountain retaining wall and the existing building, and the support member is interposed between the precast concrete plate, the precast concrete plate and the existing building. In the installation step, an axial force is introduced into the support member using the jack.

According to such a construction method of a horizontal force support structure, a horizontal force support structure for transmitting a horizontal force can be easily formed as an earthquake countermeasure during seismic isolation repair work for an existing building.
In addition, it is desirable to introduce the axial force before the completion of the retaining wall constructed along the mountain retaining wall.

  According to the horizontal force support structure and the method for constructing a horizontal force support structure of the present invention, it can be constructed easily and inexpensively, and the construction period can be shortened.

It is sectional drawing which shows the installation condition of the horizontal force support structure of this embodiment. It is a top view which shows the horizontal force support structure of FIG. It is sectional drawing which shows the horizontal force support structure of FIG. It is sectional drawing which shows the operation | work condition of the construction method of a horizontal force support structure, Comprising: (a) is before construction, (b) and (c) are excavation conditions. (A)-(c) is the plane sectional view and longitudinal section which show the construction procedure of a horizontal force support structure. (A) And (b) is sectional drawing which shows the operation | work condition of the construction method of the horizontal force support structure following (c) of FIG.

  In this embodiment, for the purpose of seismic isolation of the existing building, a horizontal force support structure that supports the existing building during the seismic isolation repair work when the seismic isolation device is interposed between the superstructure and the foundation structure. Will be described.

  As shown in FIG. 1, the horizontal force support structure 1 of the present embodiment includes a mountain retaining wall 10 formed around an existing building 2 and a support member 11 installed between the mountain retaining wall 10 and the existing building 2. And.

  The mountain retaining wall 10 is formed of steel sheet piles (sheet piles) placed around the existing building 2. In addition, the structure of the mountain retaining wall 10 is not limited, For example, you may form with a main pile cross-sheet pile, and may form with a SMW construction method.

  The mountain retaining wall 10 of the present embodiment is formed with the upper end portion protruding from the ground surface. The mountain retaining wall 10 is a so-called temporary structure and is removed after the seismic isolation repair work. The mountain retaining wall 10 may be left after the seismic isolation repair work, for example, as part of the retaining wall 3 (use of the main wall).

  The support member 11 is laid horizontally between the mountain retaining wall 10 and the existing building 2 and applies a horizontal force acting on the existing building 2 during the seismic isolation repair work to the ground around the existing building 2 (the mountain retaining wall 10). To communicate.

As shown in FIGS. 2 and 3, the support member 11 includes a main body portion 12, a base portion 13, and a connecting portion 14.
In the present embodiment, only one support member 11 is displayed, but a plurality of support members 11 are arranged in parallel along the outer surface of the existing building 2 at a predetermined interval.

The main body 12 is composed of a precast concrete plate.
The main body 12 constitutes a part of the retaining wall 3 constructed along the mountain retaining wall 10 (see FIG. 1). That is, the retaining wall 3 is formed in a state in which the main body portion 12 of the support member 11 is wound.

  A plurality of through holes 12a, 12a,... For inserting the reinforcing bars (main bars) of the retaining wall 3 are formed at the end of the main body 12 on the mountain retaining wall 10 side. Further, bolt holes 12b, 12b,... For joining to the connecting member 14 are formed at the end of the main body 12 on the existing building 2 side.

In the present embodiment, as shown in FIG. 3, two rows of through holes 12a are formed.
The through hole 12a on the mountain retaining wall 10 side is formed vertically, and the through hole 12a on the existing building 2 side is inclined.
Note that the number, arrangement, inclination angle, and the like of the through holes 12 a are not limited, and may be set as appropriate according to the reinforcement of the retaining wall 3.

  The bolt hole 12b of this embodiment is an insert for screwing a bolt. In addition, the structure of the bolt hole 12b is not limited, For example, the through-hole which penetrates a volt | bolt may be sufficient. Further, the bolt hole 12b may be formed as necessary, and may be omitted depending on the joining form of the main body 12 and the connecting member 14.

As shown in FIGS. 2 and 3, the main body 12 has a convex portion 12 c that protrudes toward the mountain retaining wall 10.
The convex part 12c is formed so that insertion into the concave part of the mountain retaining wall 10 is possible. In the present embodiment, the body portion 12 is formed in a trapezoidal shape in the center in the width direction. Further, the convex portion 12 c has a larger thickness than the main body portion 12.
In addition, the shape and arrangement | positioning of the convex part 12c are not limited. Moreover, the convex part 12c should just be formed as needed, and may be abbreviate | omitted.

  A gap between the main body 12 and the mountain retaining wall 10 is filled with a filler 16 such as mortar. In addition, the material which comprises the filler 16 will not be limited if axial force transmission between the pile 10 and the main-body part 12 is possible, For example, grout and concrete may be sufficient.

The base 13 is fixed to the side surface of the existing building 2 via a plurality of anchors 13a, 13a,.
The base portion 13 is made of H-shaped steel and is installed sideways along the side surface of the existing building 2.
In addition, the material which comprises the base 13 is not limited to H-shaped steel, For example, groove type steel and L-shaped steel may be sufficient.

The main body portion 12 and the base portion 13 are detachably connected via a connecting portion 14.
A gap is formed between the main body portion 12 and the base portion 13, and the connecting portion 14 covers the gap from above and below.

  As shown in FIG. 3, the connecting portion 14 fixes a pair of connecting plates 14 a and 14 a horizontally mounted so as to sandwich the gap between the main body portion 12 and the base portion 13 from above and below, and the pair of connecting plates 14 a and 14 a. It comprises bolts 14b and 14c. In addition, the structure of the connection part 14 is not limited, For example, it replaces with the connection board 14a and may employ | adopt a frame-shaped member.

  The connecting plate 14a is made of a steel plate. The connecting plate 14a has a plurality of through holes through which the bolts 14b and 14c are inserted.

  The bolt 14b on the main body 12 side is inserted through the through hole of the connecting plate 14a and screwed into the bolt hole 12b of the main body 12 to connect the main body 12 and the connecting plate 14a.

  On the other hand, the bolts 14c on the base 13 side are inserted through the through holes of the upper and lower connecting plates 14a, 14a and are inserted into the base 13. A pair of connecting plates 14a, 14a and the base portion 13 are connected by screwing nuts to both ends of the bolt 14c.

  A gap 16 between the base 13 and the existing building 2 is filled with a filler 16 such as mortar. In addition, the material which comprises the filler 16 will not be limited if axial force transmission between the pile 10 and the main-body part 12 is possible, For example, grout and concrete may be sufficient.

In the present embodiment, a jack 15 is interposed in the gap between the main body 12 and the base 13.
The jack 15 is interposed between the main body portion 12 and the base portion 13, thereby enabling transmission of axial force between the main body portion 12 and the base portion 13.

  In addition, it is good also as a structure which transmits axial force between the main-body part 12 and the base 13 by making the main-body part 12 and the base 13 contact | abut directly. Further, as long as the axial force can be transmitted between the main body portion 12 and the base portion 13, another member may be provided instead of the jack 15.

Next, the construction method of the seismic isolation repair work of this embodiment is demonstrated. This seismic isolation work includes the construction of a horizontal force support structure.
The construction method of the horizontal force support structure includes a mountain retaining process, a first excavation process, an installation process, a second excavation process, a seismic isolation process, a retaining wall process, and a removal process.

The mountain retaining step is a step of forming the mountain retaining wall 10 along the outer surface of the existing building 2 as shown in FIGS.
In this embodiment, the mountain retaining wall 10 is formed by placing a steel sheet pile from the ground at a position spaced from the existing building 2 at a predetermined interval.

The first excavation step is a step of excavating between the mountain retaining wall 10 and the existing building 2 as shown in FIG.
In the first excavation process, excavation is performed until the foundation 2a of the existing building 2 is exposed. In the first excavation process, a cut beam 10a is installed between the mountain retaining wall 10 and the existing building 2 as necessary as the excavation progresses.

The installation step is a step of forming the horizontal force support structure 1 by installing the support member 11 between the mountain retaining wall 10 and the existing building 2.
In this embodiment, although the support member 11 is installed in the lower end part (lower end part of the base part 2a) of the existing building 2, the installation depth of the support member 11 is not limited.

  In the installation process, first, as shown in FIG. 5A, the bracket 17 is installed on the side surface of the existing building 2 and the temporary support member 18 is installed along the surface of the mountain retaining wall 10.

  The temporary support member 18 is horizontally mounted on brackets 18 a and 18 a fixed to the surface of the mountain retaining wall 10. In addition, the fixing method of the temporary receiving material 18 is not limited. Further, the configuration of the temporary receiver 18 is not limited.

Next, as shown in FIG. 5B, the base 13 is placed on the bracket 17 and the base 13 is fixed to the existing building 2 via the anchor 13a.
After the base 13 is installed, the main body 12 is installed.

  The end of the main body portion 12 on the existing building 2 side is fixed to the base portion 13 via the connecting portion 14. The end of the main body 12 on the mountain retaining wall 10 side is fixed to the temporary support member 18. The main body 2 is fixed to the temporary support member 18 with a bolt (not shown).

  When the main body portion 12 and the base portion 13 are installed, as shown in FIG. 5C, the filler 16 is filled into the gap between the main body portion 12 and the mountain retaining wall 10 and the gap between the base portion 13 and the existing building 2.

  When the filler 16 is cured, the jack 15 is interposed between the main body 12 and the base 13, and the jack 15 is extended to introduce the axial force to the support member 10.

A 2nd excavation process is a process of excavating the lower part of the existing building 2 (foundation part 2a), as shown to (c) of FIG. 4, after forming the horizontal force support structure 1. FIG.
In the drawings, reference numeral 2b denotes an existing pile.

  The seismic isolation process is a process of installing the seismic isolation device 4 below the existing building 2 as shown in FIG.

  In the seismic isolation process, first, a new steel pipe pile 2c is added. In addition, the newly installed steel pipe pile 2c should just be extended as needed, and when a sufficient supporting force can be ensured by the foundation ground or the existing pile 2b, it is not necessary to add.

  Next, the foundation slab 2d is constructed in the space formed below the existing building 2. The foundation slab 2c is constructed by placing concrete in a state where the exposed portion of the existing pile 2b and the head of the newly installed steel pipe pile 2c are involved.

When the foundation slab 2d is constructed, a temporary support member (not shown) such as a jack is interposed between the foundation portion 2a and the newly installed steel pipe pile 2c, and the existing building 2 is temporarily received.
Then, the existing pile 2b arrange | positioned in the position where the seismic isolation apparatus 4 is installed is cut | disconnected. That is, the existing building 2 is in a state of being supported by the remaining existing pile 2b (the uncut existing pile 2b) and the new steel pipe pile 2c until the installation of the seismic isolation device 4 is completed.

Next, the seismic isolation device 4 is installed between the foundation slab 2c and the existing building 2 (foundation part 2a).
The seismic isolation device 4 of this embodiment includes a laminated rubber bearing 41 and an oil damper 42. In addition, the structure of the seismic isolation apparatus 4 is not limited.
After installing the seismic isolation device 4, the temporary support member is removed and the remaining existing pile 2b is cut.

The retaining wall process is a process of constructing the retaining wall 3 along the mountain retaining wall 10 (see FIG. 1).
The retaining wall 3 is constructed in a state where the main body portion 12 of the support member 11 is rolled up.
The construction of the retaining wall 3 may be performed simultaneously with the installation of the seismic isolation device 4 or may be performed before or after the installation of the seismic isolation device 4.

A removal process is a process of removing the base wall 13 and separating the existing building 2 as shown in FIG. 6B.
At this time, the mountain retaining wall 10 is also removed.

In addition, the clearance required for a seismic isolation function is ensured between the main-body part 12 (retaining wall 3) after removing the base 13, and the existing building 2. As shown in FIG.
Although this embodiment demonstrated the case where the seismic isolation repair work was completed in the state which made the main body part 12 protrude from the retaining wall 3, the main body part 12 does not necessarily need to protrude from the retaining wall 3. FIG.

As mentioned above, according to the horizontal force support structure 1 of this embodiment, since it can install simply, the influence on the construction period of a seismic isolation repair work can be suppressed to the minimum.
Moreover, even if an earthquake occurs during the seismic isolation renovation work, the horizontal force acting on the existing building 1 can be transmitted to the surrounding ground via the horizontal force support structure 1, so safety can be improved. It can be secured.

In addition, since the main body 12 constitutes a part of the retaining wall 3, it is possible to perform the retaining wall 3 in parallel with the seismic isolation repair work of the existing building 2, thereby shortening the construction period. Is possible. That is, the installation and dismantling time of the horizontal force support structure 1 does not depend on the process of the retaining wall 3.
Note that the horizontal force support structure 1 can be used even in the case of partially performing seismic isolation repair work depending on the size, site, etc. of the existing building 2.

  Since the support member 11 can release the connected state between the mountain tower 10 and the existing building 2 only by removing the base portion 13, it is possible to reduce the effort required to remove the horizontal force support structure 1.

  Since the main body portion 12 is formed with a plurality of through holes 12a, 12a,... For inserting the reinforcing bars of the retaining wall 3, the reinforcing bars can be positioned using the through holes 12a, 12a,. Is possible.

  As shown in FIG. 2, the support member 11 has a transmission performance of a horizontal force acting on the existing building 2 during an earthquake or the like because the convex portion 12 c of the main body portion 12 is engaged with the concave portion of the mountain retaining wall 10. Are better.

The embodiment of the present invention has been described above. However, the present invention is not limited to the above-described embodiment, and the above-described components can be appropriately changed without departing from the spirit of the present invention.
For example, in the above-described embodiment, the case where the main body portion is precast concrete has been described. However, the configuration of the main body portion is not limited, and may be a steel member, for example.

Moreover, although the said embodiment demonstrated the case where the seismic isolation repair work was performed about the existing building which has a pile foundation structure, the foundation structure of an existing building is not limited.
Moreover, although the said embodiment demonstrated the case where a mountain retaining wall was removed after construction of a retaining wall, it is not necessary to remove a mountain retaining wall necessarily.

DESCRIPTION OF SYMBOLS 1 Horizontal force support structure 2 Existing building 3 Retaining wall 4 Seismic isolation device 10 Yamadome wall 11 Support member 12 Main part (precast concrete plate)
13 Base 15 Jack

Claims (3)

A horizontal force support structure for supporting an existing building under seismic isolation repair work,
A mountain wall formed around the existing building;
A support member installed between the mountain retaining wall and the existing building,
The support member includes a precast concrete plate that forms a part of a retaining wall constructed along the mountain retaining wall and in which a plurality of through holes for inserting a reinforcing bar of the retaining wall are formed. A horizontal force support structure characterized by that. A mountain process that forms a mountain wall along the outer surface of an existing building;
An excavation process for excavating between the mountain retaining wall and the existing building;
An installation step of installing a support member between the mountain retaining wall and the existing building, and a construction method of a horizontal force support structure comprising:
The support member includes a precast concrete plate and a jack interposed between the precast concrete plate and the existing building,
In the installation step, an axial force is introduced into the support member using the jack, and a construction method of a horizontal force support structure is characterized. The method for constructing a horizontal force support structure according to claim 2 , wherein the introduction of the axial force is performed before the completion of the retaining wall constructed along the mountain retaining wall.

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