JP2009097165A - Outer shell-reinforcing structure of existing building - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance the earthquake resisting performance of an existing building by maintaining a function of the existing building on an as-is basis and mounting a seismic strengthening structure on the outside surface of a building structure. <P>SOLUTION: A pin supporting portion 20 is formed in a beam-column joint 2 on the outer surface of the existing building 1. An outer shell reinforcing frame 11 is supported by the pin supporting portion 20. The outer shell reinforcing frame 11 is composed of an outer shell beam frame 12 which continues in a beam direction, and outer shell column frames 13 which are elongated upward and downward from respective layers so that the beam-column joint can be formed of the outer shell beam frame 12 and the pin supporting portion 20, respectively. A gap between the outer shell column frames 13 elongated upward or downward is connected for the construction of the lattice-shaped outer shell reinforcing frame 11 on the outside surface of the existing building 1. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an outer shell reinforcement structure of an existing building, and the existing building function is maintained as it is, and an earthquake-resistant reinforcement structure is attached to the outer surface of the building structure to improve the earthquake resistance performance of the existing building. It relates to the outer shell reinforcement structure of buildings.

  Various seismic reinforcement methods for improving the seismic performance of existing buildings have been proposed. Broadly speaking, there are seismic reinforcement methods that require changes to the interior of the building, such as the addition of a seismic wall that is a structure and reinforcement of pillars and beams, and the outer shell surface of the building structure (hereinafter simply referred to as the outer shell). There is a seismic reinforcement method that adds a reinforcing structure consisting of a steel frame. As for the former, construction inside the building is required, so construction while using the building is difficult.

  On the other hand, in the latter seismic reinforcement method of adding a reinforcing structure to the outer shell, it is possible to examine the results of the seismic diagnosis of an existing building and add a reinforcing structure that compensates for the weakness of the existing building as appropriate. In addition, in order to attach a reinforcing structure to the outer shell of a building, for example, in the case of a commercial building, it remains to work, or in the case of an apartment, etc. There is an advantage that only a degree of influence is required. The applicant has also confirmed several known prior arts (Patent Document 1, Patent Document 2).

  Patent Document 1 shows an example in which a reinforcing steel column is attached to the outer surface of an existing beam when the existing building exhibits a “beam collapse type” failure type and the proof strength of the entire building is insufficient. When attaching this reinforced steel column, a shear pin is attached to a part of the sleeve wall of the column, and a damper is provided at the beam end to allow rotation at the beam end to absorb energy at the material end.

  Patent Document 2 exemplifies a seismic reinforcement method in which a steel frame composed of steel columns and beams is attached along the columns and beams on the outer peripheral portion of an existing structure, and a seismic structure. This steel frame is characterized in that it is integrated with a column beam frame of an existing structure by a filling method with anchor hardware and a bonding method with anchor hardware.

JP 2000-310044 A JP 2001-49874 A

  By the way, the invention disclosed in Patent Document 1 assumes a structure that exhibits a beam collapse type failure mode in which the beam strength is extremely small compared to the column strength as the object of seismic reinforcement. Only considered. Therefore, it cannot be applied when the proof strength is assumed to be insufficient in the entire frame of the existing building.

  In the invention disclosed in Patent Document 2, when integrating a steel frame integrated with a column beam with a column beam frame of an existing structure, a number of anchor hardware capable of holding a fixed state from the steel frame side is provided. Placed on the structure side of the existing structure, took measures to prevent cracks such as studs and spiral muscles between the steel frame side and the body side, and filled mortar to fill the body surface and the steel frame side web, Integration of the column beam frame of the existing structure and the steel frame is achieved by injecting a resin-based adhesive.

  In Patent Document 2, the joint portion between the existing structure and the steel frame is not limited to the entire surface of the column beam side of the structure in consideration of the stress burden ratio between the added structural system (steel frame) and the existing structure. However, if the column or beam end is not fixed at the column beam joint, the structure of the added steel frame will be the existing structure. It cannot function as a single object. That is, in order for the invention of Patent Document 2 to function effectively, it is necessary to attach the steel frame to the column beam joint of the existing structure. In that case, it becomes necessary to fix with an anchor, mortar, or an adhesive agent. In addition, a sufficient shear reinforcement structure is also required for the column beam joint portion of the steel frame, which is contrary to the demand for weight reduction of the added steel frame. Therefore, the object of the present invention is to solve the problems of the conventional technology described above, minimize the number of joints to the existing building, and prevent the influence of the external force moment on the existing building from being transmitted. It is to provide an outer shell reinforcing structure.

  In order to achieve the above-mentioned object, the present invention forms a pin support portion at a column beam joint portion on the outer surface of an existing building, a continuous outer shell beam in the beam direction, and a column beam by the outer shell beam and the pin support portion. The pin support part supports an outer shell reinforcing frame composed of an outer shell column extending upward and downward from each layer so as to form a joint, and connects the gap between the outer shell columns extending upward or downward. The lattice-shaped outer shell reinforcing structure is constructed on the side of the existing building.

  It is preferable that a damping damper is interposed at a connecting portion between the outer shell columns extending upward and downward from the respective layers.

  The vibration damper is preferably a hysteresis damper, particularly a steel damper or a friction damper. Thereby, sufficient deformation performance can be given to the outer shell reinforcing frame. It is also preferable to use an oil damper as a viscous damper or a viscoelastic damper.

  The pin support part is composed of a pin member supported by a steel plate attached to a column beam joint part of an existing building, and the steel plate uses a grout filler over a part of the existing beam joined to the column beam joint part. It is preferable to support it. Thereby, a pin support part can be reliably formed in the column beam junction of an existing building.

  The pin support portion is preferably fixed using a fixing bolt in which the steel plate is attached to a part of an existing building. As a result, the pin support portion can be securely fixed to the column beam joint portion of the existing building.

  It is preferable that the pin support portion is arranged at the same position by adjusting the position when the steel plate is attached, and the outer pillar column frame is attached to the pin support portion. Thereby, the outer shell reinforcing frame shape constructed in a lattice shape is maintained in a plane, and it is possible to prevent the frame member from being twisted when a horizontal force is applied.

  The outer shell reinforcing frame is preferably composed of a steel beam and a steel column, or a precast concrete beam and a column. Thereby, the weight reduction of an outer shell reinforcement frame and the improvement of workability can be aimed at.

  According to the present invention, when the seismic performance of an existing building is enhanced, the change in the external shape of the existing building can be minimized, and the structure of the existing building can be changed by forming a pin support portion at the column beam joint. Since the outer frame is pin supported even after completion, it is possible to suppress the effect of additional bending moment on the existing building frame. The effect of.

  Hereinafter, as the best mode for carrying out the outer shell reinforcing structure of an existing building of the present invention, the following embodiments will be described with reference to the accompanying drawings.

  FIG. 1 is an example of an outer shell reinforcing structure of the present invention, which is an intersection of an intermediate column 3 and an intermediate beam 4 on a part of floors (1st to 4th floors) of an existing building 1 of a four-story reinforced concrete structure. A state in which a pin support portion 20 for attaching the outer shell reinforcing frame 11 is installed in the beam-column joint portion 2 and a shell attached to each part of the existing building 1 so as to be supported by the pin support portion 20 1 is an overall perspective view showing a reinforcing frame 11. FIG. In the drawing, for explaining the schematic arrangement state of the outer shell reinforcing frame 11, a virtual state in which a plurality of layers of outer shell reinforcing frames 11 are arranged in an upright shape is shown.

  FIG. 2 is an overall perspective view showing a state in which each outer shell reinforcing frame 11 shown in FIG. 1 constitutes an outer shell reinforcing structure 10 attached to the existing building 1. As shown in FIGS. 1 and 2, when each outer shell reinforcing frame 11 is attached to the existing building 1, the mounting hole 15 provided in each outer shell reinforcing frame 11 is connected to each beam of the existing building 1. A pin fixing cap member 29 is put on a pin 27 (details will be described later) inserted into the pin 27 of the pin support portion 20 provided in the portion 2 and protruding from the mounting hole 15 of each outer shell reinforcement frame 11. 11 is pin-supported integrally with the beam-column joint portion 2 of the existing building 1. Further, a friction damper 30 serving as a vibration damper is interposed between the upper shell reinforcing frame 11U formed on the outer shell reinforcing frame 11 of each layer and the outer shell reinforcing frame 11L of the lower floor. Each outer shell reinforcing frame 11 can behave integrally with a horizontal acting force via a plurality of friction dampers 30 arranged in a horizontal direction.

  3 is a diagram showing the structure of the pin support 20 in the beam-column joint 2 of the existing building 1 and the outer-layer reinforcing frame 11U and the lower-layer outer frame 11L in each column. They are the front view (FIG.3 (b)) which expanded and showed the structure attached to the junction part 2, a partial cross section top view (FIG.3 (a)), and a partial cross section side surface (figure (c)).

[Configuration of Pin Support]
The structure of the pin support part 20 provided in the column beam junction part 2 of the existing building 1 is demonstrated with reference to Fig.3 (a) and FIG.3 (c). As shown in FIG. 3A, the pin support portion 20 has a configuration in which two base plates 21 and pin base plates 22 are stacked. The base plate 21 is a thick steel plate projecting from the column end to the existing beam 4 side by a predetermined length in close contact with the side surface of the existing intermediate column 3. Bolt mounting holes 23 are formed. As shown in FIGS. 3 (a) and 3 (c), the tip of the plate fixing bolt 24 mounted through the existing beam 4 is fixed to the bolt mounting hole 23 with a nut 25. At that time, a back-filling material 26 made of high-strength mortar is filled between the column surface gap generated after the level adjustment of the pin pedestal plate 22 to be described later and the beam on the back of the overhanging portion. A sufficient fastening force is applied when adjusting the installation position and fixing the nut of the plate fixing bolt 24. In this embodiment, the base plate 21 is fixed to the column beam joint 2 by eight plate fixing bolts 24 with the intermediate column 3 interposed therebetween. Further, the end of the pin base plate 22 is fillet welded on the base plate 21. As shown in FIGS. 3A, 3C and 4, a substantially cylindrical steel pin 27 that functions as the pin support portion 20 (hereinafter referred to as a pin) is provided at the substantially central position of the pin base plate 22. Are welded. A level adjustment plate 28 is fitted to the pin 27. The level adjusting plate 28 holds the outer shell reinforcing frame 11 as a structure as a structure when a pin holding hole 17 formed in a column beam joint 15 of the outer shell reinforcing frame 11 described later is loosely fitted to the pin 27. Thus, the installation position is determined in order to adjust the fitting amount. The outer shell reinforcing frame 11 is held by each pin support portion 20 with reference to the installation position. The plate fixing bolt 24 is preferably a bolt that can be nut-tightened by threading both ends of a PC steel rod having a predetermined length. Note that the pin base plate 22 can be omitted by directly attaching the pins 27 to the base plate 21. In this case, it is preferable to provide a height adjusting mechanism or the like on the pin 27 side.

  As shown in FIG. 1, each beam-column joint portion 15 of the outer shell reinforcing frame 11 having a shape continuous in the horizontal direction is point-supported at each steel pin position provided in the beam-beam joint portion 2 of the existing building 1. Is done. Finally, the entire outer shell reinforcing frame 11 is supported by pin support portions 20 arranged in a lattice shape vertically and horizontally (see FIG. 1). At this time, as shown in FIGS. 3A and 3C, the inner diameter of the pin holding hole 15 has almost no gap than the outer diameter of the pin 27, but is set slightly larger. Even when the tip of the pin 27 is fixed by the pin fixing cap 29, the moment acting on the outer shell reinforcing frame 11 through this holding position is not transmitted to the column beam joint portion 2 of the existing building 1. In addition, the pin structure of the pin support part 20 can penetrate the pin holding hole 17 formed in the column beam joint part 15 of the outer shell reinforcing frame 11 and covers the pin 27 from the outer side of the outer shell reinforcing frame 11. If the outer shell reinforcing frame 11 has a shape that does not fall off from the pin 27 and has a structure that serves as a support point for the outer shell reinforcing frame 11, a large-diameter bolt-nut structure or a nested shape is used. A male thread and a female thread are formed on two processed cylindrical bodies, and one is used as a pin and the other is used as a pin fixing cap, or various pin support structures can be employed.

[Configuration of outer shell reinforcement frame]
In the present embodiment, as shown in FIG. 4, the outer shell reinforcing frame 11 includes a beam frame 12 extending in the beam longitudinal direction by welding a narrow H-shaped steel at the beam-to-column joint 15, and a column beam. It is a processed steel frame member composed of a column frame 13 (13U, 13L) extending toward the upper layer and the lower layer at the joint 15; In general, it is preferably about 700 to 900 mm. The column width dimension of the column frame 13 is also set to be narrower than the existing columns. Also for the stiffener 15a (FIG. 4) of the beam-column joint portion 15, it is preferable to use a reinforcing plate material that can ensure the strength required for design. The beam frame 12 and the column frame 13 may have a flat appearance by attaching a design cover plate (not shown) only to the box-shaped cross section or the outer surface side of each frame in consideration of the appearance after the repair. . 2 shows an example in which the outer shell reinforcing frame 11 as the outer shell reinforcing structure 10 is attached to a part of the existing building 1. However, as a result of the seismic diagnosis, the outer shell reinforcing structure 10 is required. Needless to say, it may be applied to the range of the existing building 1. For example, in the case of a building having a piloti, the outer shell is secured without changing the existing function by arranging the outer shell reinforcing frame 11 on the outer shell surface of the open space that is not a passage while securing the space of the piloti. The reinforcing structure 10 can be applied. In addition, as a material of the outer shell reinforcing frame 11, a precast concrete column beam integrated member may be used. In that case, the shape of the frame can be set to various shapes within a manufacturable range as long as the design strength and deformation performance can be secured.

[Configuration of damping damper]
In this embodiment, a column frame 13L extending downward from the column beam joint 15 of the outer shell reinforcement frame 11 on the upper floor, and a column extending from the column beam joint 15 of the outer shell reinforcement frame 11 on the lower floor to the upper floor. A history damper is installed as a vibration damper between the frame 13U. In this embodiment, the friction damper 30 is used as a specific example of the hysteresis damper. As shown in FIG. 3 (c), the friction damper 30 has a simple configuration in which three steel plates 31 (31a, 31b, 31c) are bolted, and a central steel plate is attached to the column frame 13L on the upper floor side. The upper ends of 31b are fixed, and the lower ends of the two outer steel plates 31a and 31c are fixed to the lower frame pillar column 13U so as to sandwich the central steel plate 31b. A long hole (not shown) penetrating the three steel plates 31 is formed, and the three steel plates 31 are fastened with bolts 32 with a predetermined torque through the long holes, and each of the steel plates 31a, 31b, and 31c. The damper function is demonstrated by using friction on the contact surface.

  As a function, a horizontal force smaller than the bolt fastening force does not cause a deviation between the steel plates, but when a predetermined horizontal force (out-of-plane shear force) is applied, a uniform deviation corresponding to the horizontal force occurs. At this time, since the load deformation history curve of the friction damper 30 shows a rectangular loop, the friction damper 30 acts after the outer shell reinforcing frame 11 is deformed to a predetermined inclination angle or more, and is applied to the rigid contact portion of the outer shell reinforcing frame 11. It serves to prevent excessive deformation.

  As another configuration example of the hysteresis damper, a member shape displacement of a lattice that is bolted with a small lattice frame interposed between column members may be used. It is also preferable to interpose various viscoelastic dampers. Further, the friction damper 30 may be omitted when the displacement performance of the outer shell reinforcing frame 11 is large and the proof stress is sufficiently secured. It is preferable that the upper floor pillar member and the lower floor pillar member are integrally joined to form a single pillar member that can sufficiently follow the interlayer displacement during an earthquake.

  4 provides the pin support 20 in the beam-column joint 2 of the existing building 1 described above, and attaches the outer shell reinforcing frame 11 to the pin 27 of the pin support 20 so as to penetrate the pin holding hole 17, 3 is an exploded perspective view showing an exploded structure for fixing the tip of a pin 27 with a pin fixing cap 29. FIG. As shown in the figure, the outer shell reinforcing frame 11 can be fixed to the pin support portion 20 with high accuracy with a simple member configuration at the column beam joint portion 2 of the existing building 1.

  FIG. 5 is a perspective view showing a modification when the plate fixing bolt 24 is attached to the existing beam 4 in the vicinity of the column beam joint 2 of the existing building 1. Reinforcing bars such as shear reinforcement bars are densely arranged in the existing beam 4 in the vicinity of the column beam joint 2. Therefore, it is preferable to set the plate fixing bolt 24 in the vicinity of the beam end without providing a through hole in the beam 4. Therefore, as shown in FIG. 5, fixing bolts 24 are arranged at the upper and lower positions of the existing beam 4 using a fixing bolt fixing jig (not shown), and the surroundings are covered with high-strength grout. It is also preferable to provide a bolt support 26B integrated with the backfill portion 26A without damaging it.

The perspective view which showed the state before attaching the outer shell reinforcement frame as an outer shell reinforcement structure of this invention to the existing building 1. FIG. The perspective view which showed the state which attached the outer shell reinforcement frame and friction damper as the outer shell reinforcement structure of this invention to the existing building 1. FIG. The partial front view, the partial top view, and the partial side view which showed the structural example of the outer shell reinforcement frame as an outer shell reinforcement structure of this invention, and a friction damper. The disassembled perspective view which showed the example of attachment to the column beam junction part of the existing building of an outer shell reinforcement frame. The perspective view which showed the attachment structural example of the fixing bolt to the column beam junction vicinity of the existing building.

Explanation of symbols

1 Existing building 2 Beam-column joint of existing building 3 Existing column (intermediate column)
4 Existing beam 10 Outer shell reinforcement structure 11 Outer shell reinforcement frame 12 Beam frame 13 Column frame 15 Column beam joint 20 of outer shell reinforcement frame Pin support portion 21 Base plate 22 Pin base plate 26, 26A Backfill portion 27 Pin 29 Pin fixed Cap 30 Friction damper

Claims (11)

  A pin support part is formed at the beam-column joint on the outer surface of the existing building, and the outer-shell beam continuous in the beam direction, and the beam-to-column joint is formed by the outer shell beam and the pin support part above each layer. And the outer shell reinforcing frame extending downwardly are supported by the pin support part, and the lattice-shaped outer shell reinforcing structure is formed by connecting the gap between the outer shell pillars extending upward or downward. The outer shell reinforcement structure of the existing building, which is built on the outside surface of the existing building.   2. The outer shell reinforcing structure for an existing building according to claim 1, wherein a damping damper is interposed at a connecting portion between outer shell columns extending upward and downward from each layer.   The outer shell reinforcing structure for an existing building according to claim 2, wherein the vibration damper is a hysteretic damper.   The outer shell reinforcing structure for an existing building according to claim 2, wherein the vibration damper is a viscous damper.   The outer shell reinforcing structure for an existing building according to claim 3, wherein the hysteresis damper is a steel damper or a friction damper.   The outer shell reinforcing structure for an existing building according to claim 4, wherein the viscous damper includes an oil damper or a viscoelastic damper.   The pin support part is composed of a pin member supported by a steel plate attached to a column beam joint part of an existing building, and the steel plate is a grout filling back part over a part of the existing beam joined to the column beam joint part. The outer shell reinforcing structure for an existing building according to any one of claims 1 to 6, wherein the outer shell reinforcing structure is supported.   8. The outer shell reinforcing structure for an existing building according to claim 7, wherein the pin support portion is fixed by using a fixing bolt attached to a part of the existing building.   9. The pin support part according to any one of claims 1 to 8, wherein an installation position is aligned by adjusting a position when the steel plate is attached, and the outer pillar column frame is attached to the pin support part. The outer shell reinforcement structure of the existing building according to item 1.   The outer shell reinforcing structure for an existing building according to claim 1, wherein the outer shell reinforcing frame is made of an integrated member of a steel beam and a steel column.   The outer shell reinforcing structure for an existing building according to claim 1, wherein the outer shell reinforcing frame is made of an integrated member of a precast concrete beam and a precast concrete column.

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