JP6289912B2 - Temporary receiving method and structure of vertical load in seismic isolation retrofit work - Google Patents

Description

  The present invention relates to a vertical load provisional receiving method and provisional reception in a seismic isolation retrofit work, for example, when a seismic isolation device is newly installed in a column in an intermediate layer of an existing building, or the seismic isolation device is replaced. Concerning structure.

  Conventionally, the provisional receiving of the vertical load of the seismic isolation retrofit supports a large load of several thousand kN or more because the vertical axial force acting on the existing column where the seismic isolation device is newly installed is directly received. In addition to the method of receiving the axial force directly by the temporary support column, there are various methods of temporarily receiving the load receiving bracket made of steel or reinforced concrete (RC) to the existing housing with the PC steel material. For example, as shown in FIG. 4A, a seismic isolation device installation method described in Patent Document 1 is known as an example of an RC bracket. Moreover, as shown in FIG. 4 (B), as an example of the steel bracket, the seismic isolation method described in Patent Document 2 and the other method of installing the seismic isolation device described in Patent Document 3 (not shown). It has been known.

JP 2001-49873 A Japanese Patent No. 3725818 JP 2002-227425 A

  However, in the conventional method for temporarily receiving the vertical load in the seismic isolation retrofit work, for example, in the example of the steel bracket, the rigidity is low and the axial force that can be borne is less than 800 t. Further, in the example of the RC bracket, although the rigidity is high, a concrete curing period is required for installation, and the construction period becomes long. Furthermore, in order to remove the concrete which concerns on the said RC bracket, there exists a subject said that it costs. The provisional receiving method of the vertical load in the seismic isolation retrofit construction according to the present invention has been proposed in order to solve such a problem.

The gist for solving the above problems of the vertical load provisional receiving method in the seismic isolation retrofit construction according to the present invention is to install a seismic isolation device at a location where a part of an existing pillar of a building is cut. At this time, the temporary receiving member that temporarily receives the axial force of the building is crimped by a crimping member that penetrates the existing column, and the axial force applied to the existing column is placed on the temporary receiving member and the temporary receiving member. In the temporary receiving method of temporarily receiving with a jack, when the temporary receiving member is a precast concrete (PCa, sometimes referred to below) bracket divided into upper and lower parts, the horizontal dividing surface of the bracket is With the upper and lower precast concrete brackets installed on the existing columns, these are viewed from the side, and the position where the axial force is applied on the upper surface of the upper precast concrete bracket and the lower side It is that is an inclined face perpendicular to the connecting inner corners of the bottom of the precast concrete bracket phantom.

  A shear key projecting from a high-strength mortar interposed between the joint surface of the precast concrete bracket and the existing column is interposed between the joint surface of the existing column and the joint surface.

  In the case where the temporary support member is a precast concrete bracket divided into upper and lower parts, the divided upper and lower precast concrete brackets are installed on an existing column only with a horizontal pressure bonding material.

The gist for solving the above-mentioned problems of the vertical load provisional receiving structure in the seismic isolation retrofit construction according to the present invention is to install a seismic isolation device at a location where a part of an existing pillar of a building is cut. At this time, the temporary receiving member that temporarily receives the axial force of the building is crimped by a crimping member that penetrates the existing column, and the axial force applied to the existing column is placed on the temporary receiving member and the temporary receiving member. In the temporary receiving structure for temporarily receiving with a jack, when the temporary receiving member is a precast concrete bracket divided vertically, the horizontal dividing surface of the bracket has the upper and lower precast concrete brackets installed on the existing pillars. When these are viewed from the side, the position where the axial force is applied to the upper surface of the upper precast concrete bracket and the lower precast concrete bracket It is that is an inclined face perpendicular to the connecting inner corners of the parts phantom.

  A shear key projecting from a high-strength mortar interposed between the joint surface of the precast concrete bracket and the existing column is interposed between the joint surface of the existing column and the joint surface.

  In the case where the temporary support member is a precast concrete bracket divided into upper and lower parts, the divided upper and lower precast concrete brackets are installed on the existing pillars only with the horizontal pressure bonding material.

  According to the provisional receiving method and structure of the vertical load in the seismic isolation retrofit construction of the present invention, since the PCa bracket reduced in size and weight is used, the seismic isolation retrofit construction with a high axial force (8000 kN or more) is possible. It becomes possible. Further, by using the PCa bracket, the curing time until the strength is developed compared to the RC bracket can be omitted, and the work time at the site can be shortened. In addition, by being divided into the PCa bracket, it becomes light and easy to handle, and the workability on site is improved. Furthermore, an excellent effect is obtained that it is easy to remove the PCa bracket.

It is a partially expanded perspective view of the example which divided | segmented the temporary support member into the horizontal direction in the temporary support structure of the vertical load in the seismic isolation retrofit construction which concerns on this invention. It is a partial side view of the example which divided | segmented the temporary support member into the horizontal direction in the temporary support structure of the vertical load in the seismic isolation retrofit construction of the same invention. It is a partially expanded perspective view of the example which divided | segmented the temporary support member into the perpendicular direction by the temporary support structure of the vertical load in the seismic isolation retrofit construction which concerns on this invention. It is the side view (A) which shows the example of RC bracket which shows the seismic isolation retrofit construction concerning a prior art example, and the side view (B) which shows the example of steel brackets.

  The vertical load provisional method in the seismic isolation retrofit work according to the present invention uses the divided PCa brackets 3a and 3b as shown in FIG. 1, or the divided PCa bracket 3d as shown in FIG. To do.

  In the seismic isolation retrofit construction according to the present invention, as shown in FIG. 1, the seismic isolation device 10 is installed at a location where a part of the existing pillar 2 of the building is cut. At that time, temporary receiving members (PCa brackets 3a, 3b) for temporarily receiving the load of the building are filled and solidified with high-strength mortar 4 between the temporary receiving member and the surface of the existing pillar 2, Crimping is performed with a crimping member (PC steel rod 7) penetrating the existing pillar 2, and the axial force applied to the existing pillar of the building is temporarily received with the temporary receiving member and the jack 9 placed on the temporary receiving member. This is a method for temporarily receiving a vertical load.

  The procedure of the method for temporarily receiving the vertical load will be described. First, the PCa brackets 3a and 3b are formed in a factory (or a site in some cases). The PCa brackets 3a and 3b, which are the temporary receiving members, are formed as precast concrete brackets that are reduced in size and weight in a state where the PCa brackets 3a and 3b are divided into upper and lower parts in advance.

  When the temporary receiving member is an upper PCa bracket 3a and a lower PCa bracket 3b, which are divided into upper and lower parts, as shown in FIG. When the upper and lower PCa brackets 3a and 3b are installed on the upper side of the PCa bracket 3a, the positions where the axial force is applied to the upper surface of the upper PCa bracket 3a and the lower inner corners of the lower PCa bracket 3b are connected. The inclined surface is perpendicular to the imaginary line 8.

  The reason why the dividing surface 3c is inclined is that the upper PCa bracket is against the axial force actually applied to the temporary receiving member (PCa bracket) when temporarily receiving the axial force applied to the additional column 2 and the existing column 2a. This is because the split surface 3c of the lower PCa bracket 3b is a surface perpendicular to the axial force.

  Further, a shear key 5 is appropriately provided on the joint surface of the PCa brackets 3a and 3b with the existing column 2 so as to protrude into the high-strength mortar 4 interposed between the joint surface and the joint surface of the existing column 2 facing the joint surface. Projected in number and arrangement.

  With the shear key 5, the slip fracture surface becomes a joint surface between the high-strength mortar 4 and the existing pillar 2. Further, through holes for inserting a PC steel rod are formed in the PCa brackets 3a and 3b in the horizontal direction and the vertical direction. In this way, the PCa brackets 3a and 3b are manufactured in advance at the factory, and transported and carried into the site by a truck or the like.

  Next, the existing pillar 2a of the building is reinforced to temporarily receive a vertical load. For this purpose, as shown in FIG. 1, a construction for horizontally drilling holes for PC steel bars in the existing pillar 2a is performed. Thereafter, a capital is added to receive the hydraulic jack 9 at the stigma of the existing pillar 2a. In addition, a PC steel rod sheath tube is installed in the extension column 2 according to the hole drilled in the existing column 2a, and reinforced concrete is placed on the column base to expand the existing column 2a. Install. In this way, the extension pillar 2 is formed.

  After the concrete of the capital is solidified and reaches a predetermined strength, the tension material embedded by the post tension method is pulled with a jack, and a predetermined tension is introduced to apply prestress.

  Next, the PCa brackets 3 a and 3 b are carried into the site, the PC steel rod 7 is inserted into the sheath tube of the extension column 2, and the PCa brackets 3 a and 3 b are installed on the existing column 2. Further, as shown in FIG. 2, at the same time, the PCa brackets 3a and 3b divided in the horizontal direction by the PC steel rods 6 penetrating through the vertical through holes in the PCa brackets 3a and 3b are connected to each other with the plate 6a and the fixing nut 6b. Tighten with to crimp and integrate.

  Further, as shown in FIG. 2, a gap maintaining spacer or the like is sandwiched in the gap (about 20 to 30 mm as an example) between the PCa brackets 3a and 3b and the extension pillar 2, and a mortar formwork is further formed. After assembling around the gap, high strength mortar 4 is filled.

  After the extension pillar 2 and the high strength mortar 4 reach a predetermined strength, the PC steel rod 7 is pulled with a jack and a predetermined tension is introduced. As a result, the axial force of the upper frame can be supported by the frictional force between the PCa brackets 3a and 3b and the extension column 2. Thereafter, a necessary number of hydraulic jacks 9 are installed on the PCa bracket 3a.

  The hydraulic jack 9 is operated to jack up, and the long-term axial force of the upper frame of the building is supported by the extension pillar 2 and the existing pillar 2a via the PCa brackets 3a and 3b. Then, the existing pillar 2a exposed to the upper part from the additional pillar 2 is cut with a wire saw.

  A new seismic isolation device 10 is installed at a predetermined position at the cutting position of the existing pillar 2a. Furthermore, a reinforcement part is provided in the upper and lower sides of the seismic isolation apparatus 10, and reinforced concrete 2b and 2c are laid in this reinforcement part. After this concrete has hardened, grout is poured into the gap.

  After the reinforced concrete 2b, 2c of the reinforcing portion and the grout of the gap portion reach a predetermined strength, the hydraulic jack 9 is jacked down. Thereby, the long-term axial force of the upper frame of the building is transferred to the seismic isolation device 10.

  Next, the fixing nuts 6 b and 7 b of the PC steel bars 6 and 7 are loosened and removed, and the PCa brackets 3 a and 3 b are removed from the additional pillar 2. The grout is filled in the holes in the additional pillar 2 and the existing pillar 2a after the PC steel rod 7 is removed. In this way, the method for temporarily receiving the vertical load by the temporary support structure 1 is completed.

  As another example of the vertical load temporary receiving structure 1, as shown in FIG. 3, there is a structure using a PCa bracket 3d divided by a dividing surface 3e in the vertical direction. The seismic isolation device 10 can be easily installed by reducing the size and weight by dividing in such a vertical direction.

  In addition, as another embodiment of the vertical load temporary receiving method, when the temporary receiving member is the PCa brackets 3a and 3b divided into upper and lower parts, the upper and lower PCa brackets 3a and 3b are made of a horizontal pressure bonding material. Installed on the extension pillar 2 and the existing pillar 2a only with a certain PC steel rod 7. That is, it is a method of omitting the PC steel bar 6 that presses the PCa brackets 3a and 3b in the vertical direction.

  In FIG. 2, the PC steel bar 6 becomes substantially unnecessary when tension is introduced by the horizontal PC steel bar 7. Accordingly, the PC steel bar 6 is not required, the material cost is reduced, installation such as attachment and tension is not required, and the work period is shortened.

  According to the provisional receiving method of vertical load and its provisional receiving structure in the seismic isolation retrofit construction according to the present invention, the PCa bracket of the provisional receiving member can be divided and reduced in size, so that the existing pillars in the intermediate layer of the building, Or it is applicable not only when newly installing a seismic isolation device with respect to a foundation but also when exchanging old and new seismic isolation devices.

1 temporary support structure,
2 additional pillars, 2a existing pillars,
3a, 3b PCa brackets divided horizontally,
3c dividing plane,
3d PCa bracket divided vertically,
3e Dividing surface,
4 high strength mortar,
5 Shea key,
6 PC steel bar,
7 PC steel bar,
8 virtual lines,
9 Hydraulic jack,
10 Seismic isolation device,
11 Capital.

Claims (6)

When installing a seismic isolation device at a location where a part of an existing pillar of a building was cut,
Crimp with a crimping member that penetrates the existing pillar a temporary receiving member that temporarily receives the axial force of the building,
In the temporary receiving method of temporarily receiving the axial force applied to the existing pillar with the temporary receiving member and the jack placed on the temporary receiving member,
When the temporary support member is a precast concrete bracket that is divided into upper and lower parts, the horizontal dividing surface of the bracket is viewed from the side with the upper and lower precast concrete brackets installed on the existing pillar, and It is an inclined surface perpendicular to the imaginary line connecting the position where the axial force is applied on the upper surface of the precast concrete bracket and the lower inner corner of the lower precast concrete bracket,
A method for temporarily receiving vertical loads in seismic isolation retrofit construction. The joint surface with the existing pillar in the precast concrete bracket is provided with a shear key projecting into the high-strength mortar interposed between the joint surface and the joint surface of the existing pillar facing the joint surface,
The provisional receiving method of the vertical load in the seismic isolation retrofit construction of Claim 1 characterized by these. When the temporary receiving member is a precast concrete bracket divided into upper and lower parts, installing the divided upper and lower precast concrete brackets on the existing pillar only with the horizontal pressure bonding material,
The provisional receiving method of the vertical load in the seismic isolation retrofit construction of Claim 1 or 2 characterized by these. When installing a seismic isolation device at a location where a part of an existing pillar of a building was cut,
Crimp with a crimping member that penetrates the existing pillar a temporary receiving member that temporarily receives the axial force of the building,
In the temporary receiving structure that temporarily receives the axial force applied to the existing pillar with the temporary receiving member and the jack placed on the temporary receiving member,
When the temporary support member is a precast concrete bracket that is divided into upper and lower parts, the horizontal dividing surface of the bracket is viewed from the side with the upper and lower precast concrete brackets installed on the existing pillar, and It is an inclined surface perpendicular to the imaginary line connecting the position where the axial force is applied on the upper surface of the precast concrete bracket and the lower inner corner of the lower precast concrete bracket,
A vertical load temporary support structure for seismic isolation retrofit construction. The joint surface with the existing pillar in the precast concrete bracket is provided with a shear key projecting into the high-strength mortar interposed between the joint surface and the joint surface of the existing pillar facing the joint surface,
The temporary receiving structure of the vertical load in the seismic isolation retrofit construction of Claim 4 characterized by these. In the case where the temporary support member is a precast concrete bracket divided into upper and lower parts, the divided upper and lower precast concrete brackets are installed on existing pillars only with a horizontal pressure bonding material,
The temporary receiving structure of the vertical load in the seismic isolation retrofit construction of Claim 4 or 5 characterized by these.

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