JP3222831B2 - Seismic retrofit structure for column and beam members - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seismic retrofitting structure for columns and beams, and more particularly to a seismic retrofitting structure capable of rapidly reinforcing columns and beams of an existing building while using the building. .

[0002]

2. Description of the Related Art The Hyogoken-Nanbu Earthquake in January 1995 caused serious damage to various structures. In particular, many columns and bridge piers of reinforced concrete structures, even those appropriately designed according to the design standards at that time, lacked the shear strength and toughness of the members, and often showed rapid brittle fracture. For this reason, after the earthquake, existing buildings have been subjected to various seismic evaluations to determine whether or not they have seismic performance. Buildings determined to be structurally ineligible as a result of the seismic assessment need to be refurbished and reinforced to ensure proper seismic performance. Typical methods for seismic reinforcement of reinforced concrete columns and steel-framed reinforced concrete columns include a steel plate reinforcing method, a reinforcing fiber sheet reinforcing method, and a member cross-sectional widening method.

[0003]

However, these seismic retrofitting and seismic retrofitting methods require finishing work for existing reinforced concrete columns and foundation work for reinforcement work as common preparation work. Among the respective construction methods, the steel plate reinforcement method includes welding work, which is an important work process, in addition to the work of installing a reinforcing steel plate. In addition, since the reinforcing fiber sheet reinforcing method uses an adhesive material or a solvent for attaching the sheet, a large-scale temporary ventilation facility is required.
Furthermore, in the method of widening the cross section of a concrete column, a formwork or concrete placing work for covering the existing column is required. These operations are expected to generate noise, dust, vibration, gas, and the like, and it is difficult to carry out the seismic retrofitting work in a state where the user is living or working in an existing building.

[0004] Further, since materials and the like have to be carried in by using an existing elevator or other elevating device, the materials to be used need to be in units of an appropriate size.

Further, from the structural point of view, the members reinforced with earthquake resistance are sufficiently reinforced by the restraining effect of the fiber sheet if the column can be wound in the circumferential direction in the reinforcing fiber sheet reinforcing method or the like. Although a strong reinforcement effect can be expected, its evaluation method has not been established for columns with sleeve walls or earthquake-resistant walls.

[0006] On the other hand, it is necessary to reinforce the shear strength of a reinforced concrete beam arranged to support the lower surface of the slab. Conventionally, a deformed reinforcing bar is bent into a U-shape to a dimension that surrounds the existing beam cross section to form a shear reinforcement, and the upper end of the shear reinforcement penetrates to the upper surface of the slab and is fixed by a known fixing method, In addition, a concrete section widening method has been performed in which a concrete form is attached and concrete is poured so as to cover the shear reinforcement.

As described above, the conventional reinforcing method is mostly used for independent columns, and is effective for sleeve walls, columns with earthquake-resistant walls, and slab support beams which are often arranged in actual existing reinforced concrete buildings. At present, no seismic retrofitting method has been established.

Accordingly, an object of the present invention is to solve the above-mentioned problems of the prior art and to provide an earthquake-resistant structure of columns and beam members having a high earthquake-resistance effect that can be reinforced using an existing building as a facility. It is in.

[0009]

In order to achieve the above object, the present invention is to divide the outer periphery of an existing column into two parts in the circumferential direction.
When they are united,
Pleated sheath with a single spiral inside
Stack concrete reinforcement panels in multiple layers
Along with the sheath inside the reinforcing panel of each step.
Wiring the upholstery, the fixed provided on the outer peripheral surface of the reinforcing panel
In the attachment portion, both ends of the tensile member are fixed, and the existing pillar and the reinforcing panel are integrated.

[0010]

[0011]

[0012]

[0013]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view of an embodiment of the present invention. FIG. 1 shows a precast reinforced concrete reinforcing panel 10 (hereinafter referred to as a reinforcing panel 10) from a floor surface 2 of a reinforced concrete existing column 1 (hereinafter referred to as an existing column 1) which is an independent column to a position below a beam (not shown). FIG. 2 is a schematic perspective view showing an example of seismic retrofitting. FIG. 2 is a perspective view showing one step of the reinforcing panel 10 shown in FIG.
FIG. 3 is a plan sectional view showing a state in which the reinforcing panel 10 shown in FIGS. 1 and 2 is attached to the existing column 1.

As shown in FIG. 1, the reinforcing panels 10 used in the present invention are arranged so that three columns are stacked and the existing column 1 is sandwiched from the side. Further, each reinforcing panel 10 includes a cable 2 spirally wired inside the panel.
0 and is integrated with the existing column 1. At this time, a gap (3) between the inner surface of the reinforcing panel 10 and the existing column 1 is filled with a filler (not shown).
The integration of the cross section of the column 0 and the column 1 is achieved.

FIG. 2A is a perspective view showing a reinforcing panel 10 constituting one stage. The reinforcing panel 10 is used as a pair of opposing precast reinforced concrete members having a substantially U shape in plan view. In this embodiment, a lightweight concrete product using a lightweight aggregate is used in order to reduce labor for transportation and assembly. Inside the panel, a synthetic resin sheath 15 is embedded as shown by a broken line in FIG. The synthetic resin sheath is arranged such that when the two reinforcing panels 10 are aligned in a substantially rectangular shape in plan view, the entire periphery thereof spirals around the reinforcing panel 10. The reinforcing panel 10 is stacked in a plurality of stages according to the height of the existing column 1 and a cable 20 (see FIG. 1) as a shear reinforcing bar is laid in the sheath 15 to fix the ends with a predetermined tension. With this, the column cross section can be increased. At this time, the sheath 15 embedded in the panel is shown in FIG.
As shown in (1), a predetermined curvature is provided at the corner 15a, and is set so that the tensile friction at the corner 15a is reduced when the cable 20 is laid inside.

When these reinforcing panels 10 are stacked, they can maintain the integrity in the vertical direction, and the cross sections shown in FIGS. 2B and 2C so that the filler injected into the gap 3 does not leak. Preferably, it is shaped. In the reinforcing panel 10 having a sectional shape shown in FIG.
10b, a square groove 11 is formed in the longitudinal direction.
The seal material 12 can be attached inside. As the sealing material 12, rubber packing or the like can be used. FIG. 2C shows a cross section of the reinforcing panel 10 in which a square projection 13 extends in the longitudinal direction on the panel upper surface 10a and a square groove 11 is formed on the lower surface 10b. Reinforcement panel 10
Are piled up, the ridges 1 of the lower reinforcing panel 10
3 fits into a square groove (not shown) formed on the lower surface of the upper reinforcing panel 10. Thereby, it is possible to prevent the displacement in the horizontal direction when the reinforcing panels 10 are stacked. In addition, it is possible to prevent the opposed reinforcing panels 10 at the same height by providing square groove-shaped irregularities in the connection of the opposing side sides 10c.

In this embodiment, a small-diameter PC steel strand is used for the cable 20 as a tensile member. As the material, for example, the symbol SWP specified in JIS G 3536 is used.
R2 and SWPD3 are preferred. Other cables 20
It is preferable to use a braided cable made of aramid fiber, which is a reinforced long fiber. In addition, PAN-based carbon fiber, pitch-based carbon fiber, polyimide fiber, boron fiber,
It is also preferable to use a cable 20 using a reinforced long fiber such as an alumina fiber. Cable 2 of these reinforcing fibers
Since 0 has flexibility, it can be smoothly inserted into the sheath 15.

As a structure of the fixing portion 21 at the end of the cable 20, a well-known wedge system is suitable, but since the force required for fixing is not so large, it is necessary to use a suitable cable gripping jig to fix the cable. Can also.

FIG. 4 shows an existing pillar 1 with sleeve walls 4 attached to both sides.
FIG. 2 is a plan sectional view showing an example in which is subjected to seismic reinforcement with a reinforcing panel 10 and a cable 20. When the sleeve wall 4 is provided, the side 10c of the reinforcing panel 10 is shortened by the thickness of the sleeve wall 4, and the reinforcing panel 1 is sandwiched by the sleeve wall 4.
0 is installed on the column periphery. Further, a through hole 4a is provided in a part of the sleeve wall 4 in order to route the cable 20 through the reinforcing panel 10 and the sleeve wall 4. The through hole 4a provided in the sleeve wall 4 may be adjusted to the position of the cable insertion opening 10d on the end face of the reinforcing panel 10 to be used (see FIG. 2). Also, the side 1 of the pair of reinforcing panels 10 depends on the position where the sleeve wall 4 is joined to the pillar 1.
The length of 0c may be different.

FIG. 5 is a plan sectional view showing an example in which an existing column 1 having a sleeve wall 4 and an earthquake-resistant wall 6 is seismically reinforced by a reinforcing panel 10 and a cable 20. When the reinforcing panel 10 is attached to the existing pillar 1 having such a cross-sectional shape, the reinforcing panel 10 is used by combining a flat reinforcing panel 10A and two L-shaped reinforcing panels 10B. As in the case of FIG. 4, through holes 4a, 6a through which the cable 20 passes are provided in a part of the sleeve wall 4 and the earthquake-resistant wall 6, so that the three reinforcing panels 10A, 10B and the existing pillar 1 are integrated. be able to. In addition, when the cross-section and the amount of shear reinforcement are sufficient, the flat reinforcement panel 10A can be omitted. In that case, it is preferable that the cable 20 be wired in a U-shape and the fixing portion 21 be provided on the outer surface of the sleeve wall 4.

FIG. 6 is a sectional view showing an example in which the shear reinforcement of the existing beam 7 receiving the slab 5 is performed by the reinforcement panel 10 and the cable 20. As shown in the figure, a U-shaped reinforcing panel 10C is attached so as to receive the entire existing beam 7 from below. As a procedure for reinforcing the existing beam 7, first, floor through holes 5a are provided in advance in the slabs 5 on both sides where the existing beam 7 passes. On the other hand, the end of the cable 20 inserted into the U-shaped reinforcement panel 10C is inserted into the floor through-hole 5a from below, and the cable 20 is pulled up from the upper surface of the slab 5, thereby increasing the reinforcement panel 10C.
Can cover the existing beam 7 from below. Cable 20
Are fixed on the upper surface of the slab 5, the existing beam 7 and the reinforcing panel 10C can be integrated. As another method, the reinforcing panel 10C is temporarily received so as to cover the existing beam 7 from below, and the cable 20 is connected to the reinforcing panel 1 from the upper surface of the slab 5 through the floor through hole 5a.
Alternatively, the cable may be inserted into the OC, and the other end of the cable may be projected to the upper surface of the slab 5 through the other floor through hole 5a to fix the cable. At this time, the cable 20 functions to suspend the reinforcing panel 10C and to function as a beam shear reinforcing member.
3 to 6, the reinforcing panel 10 and the existing pillar 1
A filler 8 is filled between the surface and the surface, and the reinforced columns and beam sections are widened by the existing columns 1 and the existing beams 7 and the attached reinforcing panels 10 (10A, 10B, and 10C), respectively. It can be a cross section. Further, the reinforcing panel 10 is used so that the filler 8 does not leak out of the reinforcing panel 10.
It is preferable to attach a sealing material 12 to a contact portion between the side wall 10 c and the sleeve wall 4 and the earthquake-resistant wall 6.

FIG. 7 shows a pillar 1 of an existing reinforced concrete building.
It is the side view which showed typically the structural example which performed the seismic-proof reinforcement of the beam 7 and. As shown in the figure, the beam 7 supporting the upper floor slab 5A is covered from below by a plurality of U-shaped reinforcing panels 10C, and the beam 7 is suspended from the upper floor slab 5A by the cable 20 so as to suspend the reinforcing panel 10C. And integrated. At this time, the cable 20 supporting the reinforcing panel 10C is
In the vicinity, it is preferable to reduce the arrangement interval so that a sufficient amount of shear reinforcing material can be secured. Also, as shown in the figure, a modified reinforcing panel 10D is formed so as to cover the entire connecting portion 9 between the column 1 and the beam 7, and the connecting portion 9 is reinforced with the deformed reinforcing panel 10D to provide a seismically reinforced connection. It is preferable that the stress is smoothly transmitted at the portion 9 (structurally, the beam-column joint). In addition,
If the deformed reinforcing panel 10D has a complicated shape, it may be made of steel plate instead of precast concrete. In the case where the cable 20 cannot be used as the attachment means, the cable 20 can be fixed by a plurality of post-fixed anchors (not shown).

Next, a procedure for constructing the seismic retrofit structure will be described with reference to FIGS. FIG. 8 illustrates a construction example in which the existing column 1 to which the sleeve wall 4 is attached is subjected to seismic reinforcement.
In this construction example, as shown in FIG.
The reinforcing panel 10 that can be covered in three steps to the bottom is used. First, before stacking the reinforcing panels 10, FIG.
As shown in (a), a cable through hole 4a is drilled at a position where the cable 20 penetrates the sleeve wall 4 using a drilling tool such as a concrete drill. Since the position of the cable insertion port 10d of the reinforcing panel 10 is determined in advance during the through-hole drilling operation, the sleeve wall 4 can be marked using a template. When drilling concrete in an existing building, it is preferable to use a high-frequency vibration type concrete drill capable of reducing the generation of noise and dust.

Next, the reinforcing panel 10 is installed so as to sandwich the existing column 1 from the floor 2. The cable 20 is connected to the reinforcing panel 10 while the existing pillar 1 is sandwiched between the pair of reinforcing panels 10.
(See FIG. 8B). By fixing the end of the cable 20 in this state, the reinforcing panel 10 and the pillar 1 can be integrated (FIG. 8).
(C)). By repeating this procedure, the reinforcing panels 10 are stacked below the beams 7. The sealing material 12 is attached to the upper and lower surfaces 10a of the reinforcing panel 10 so that the grout material does not leak outside from the panel joint. With the reinforcing panels 10 stacked below the beams 7 in this way, grout material is injected through grout injection holes provided in a part of the reinforcing panel 10 (see FIG. 8D). Thereby, the gap generated between the inner surface of the reinforcing panel 10 and the surface of the existing column 1 can be filled, and the existing column 1 and the reinforcing panel 10 can be structurally integrated into one section. As a grout material, an epoxy resin or the like can be used in addition to cement milk.

[0025]

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of a column seismic retrofit structure according to the present invention.

FIG. 2 is a perspective view and a panel cross-sectional view showing an example of a precast concrete reinforcing panel used in the earthquake-resistant reinforcing structure of the present invention.

FIG. 3 is a plan sectional view showing one embodiment of the seismic reinforcement structure of the independent column according to the present invention.

FIG. 4 is a plan sectional view showing an embodiment of a seismic retrofit structure for a column with a sleeve wall according to the present invention.

FIG. 5 is a plan sectional view showing an embodiment of a seismic retrofit structure for a column with a sleeve wall and a seismic wall according to the present invention.

FIG. 6 is a cross-sectional view showing an embodiment of the slab support beam seismic reinforcement structure of the present invention.

FIG. 7 is a side view showing an embodiment of an earthquake-resistant reinforcement structure for beams and columns of an existing building.

FIG. 8 is a construction sequence diagram showing a construction procedure of a column seismic retrofit structure according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Existing pillar 4 Sleeve wall 6 Earthquake-resistant wall 7 Existing beam 10, 10A, 10B, 10C Precast concrete reinforcing panel 15 Sheath 20 Cable

Claims (1)

(57) [Claims] 1. A precast concrete in which a sheath is piped inside so as to form a single spiral in the circumferential direction from the lower end to the upper end of the panel when it is divided into two parts in the circumferential direction and joined so as to cover the outer periphery of the existing column. Along with stacking the reinforcing panels in a plurality of stages, wiring a tensile member to the sheath inside the reinforcing panel of each stage, and fixing both ends of the tensile member with a fixing portion provided on the outer peripheral surface of the reinforcing panel, An earthquake-resistant reinforcement structure for a column member, wherein an existing column and the reinforcing panel are integrated.