JP2003227236A - Permanent and emergent aseismatic reinforcement method for column with wall - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To permanently and emergently improve the tenacity and horizontal yield strength of a column with a wall. <P>SOLUTION: The existing column with a wall is formed by a column part where a number of main reinforcements elongated along the vertical direction of a structure and a number of the hoops surrounding the main reinforcements are included and a wall part where a number of horizontal reinforcements and vertical reinforcements are included and which is partially connected to the column part. In applying permanent and emergent aseismatic reinforcement to the above column, the wall part is clamped together with the column part by at least two plates disposed corresponding to each other, the plates are temporarily stopped by two or more tightening members penetrating the plates and wall part, and then increased concrete or mortar is placed in a gap formed between the plates and the column part and the wall part and hardened. Subsequently the tightening members are tightened up to introduce pre-stress. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for permanent and emergency seismic reinforcement of a concrete structure in the field of construction and civil engineering, particularly a column with a wall where at least a part of the column is connected to the wall. .

[0002]

2. Description of the Related Art Conventionally, reinforced concrete structures such as middle- and high-rise buildings or bridges have often used rod-shaped columns and beams, and the members are loaded with bending moments and shearing forces from various directions. Since the axial compressive force is constantly applied to the member, the member is reinforced so as not to be easily broken even when it is subjected to an excessive load such as an earthquake (Patent Document 1, Patent Reference 2).

[0003]

[Patent Document 1] Japanese Patent Laid-Open No. 2000-34842.

[0004]

[Patent Document 2] Japanese Patent Laid-Open No. 9-88238.

By the way, most of the techniques related to this type of seismic strengthening (reinforcement) focus on columns, and passive seismic resistance for securing the toughness of columns by providing slits at the boundaries between walls. Although many reinforcement methods have been proposed, the toughness and strength of seismic reinforcement including walls that intervene between columns (seismic walls) and walls that are associated with columns (sleeve walls, waist walls, hanging walls, etc.) So far, few new proposals have been made on active methods of improving both of them.

[0006]

The object of the present invention is to dramatically improve the seismic performance (proof strength and toughness) of existing columns with walls, maintain them permanently, and damage them by the earthquake. Immediately after that, we are proposing a new seismic retrofitting method that allows relatively easy temporary reinforcement.

[0007]

DISCLOSURE OF THE INVENTION The present invention provides a column portion including a plurality of main bars extending along the longitudinal direction of a structure and a plurality of stirrups arranged so as to surround these main bars, An existing walled column consisting of a number of horizontal and vertical lines and a wall part that is connected by at least a part of the column part is facing at least 2 when applying permanent and temporary seismic reinforcement. After sandwiching the wall portion together with the pillar portion by a single plate and temporarily fixing the plate with a plurality of binding members penetrating together with the wall portion, a gap is formed between the plate and the pillar portion and the wall portion. A permanent and temporary seismic retrofitting method for a column with a wall, characterized in that concrete or mortar is strengthened by hardening and then the binding member is tightened to introduce prestress.

According to the present invention, the plate is arranged on the entire height of the pillar portion, or on the two surfaces or the three surfaces facing or around the stigma and the pedestal portion, and the corner pieces are arranged on the corner portions of the tie member. It is desirable to crimp the plate to the column portion while tightening the corner piece to introduce prestress.

Further, in the present invention, the proof strength, rigidity and deformability can be controlled by adjusting the length and width of the concrete or mortar to be additionally reinforced by changing the size of the plate and the arrangement area.

When the concrete or mortar is not overstretched, a corner piece or a strip is used to directly dispose the plate on the pillar or the wall and tighten the fastening member to introduce prestress. Crimp.

Particularly advantageously, the wall portion is a seismic wall, a waist wall, a droop wall or a sleeve wall.

It is also possible to previously dispose a reinforcing bar by a post-installed anchor in the gap formed between the plate and the column portion and the wall portion to further increase the bending strength.

The binding members can be arranged at intervals along the width direction and the lengthwise direction of the wall portion, and the arrangement intervals along the width direction of the wall portion should be close in the region near the column portion. desirable.

The binding members can be arranged at substantially equal intervals in the longitudinal direction of the wall portion, but they are dense in the vicinity thereof including the head and legs of the walled column. Is preferred.

Further, according to the present invention, at least two plates which are arranged to face each other, the strip plates projecting beyond the edge portions thereof are respectively arranged so as to overlap with each other, and the strip members are pierced between the strip plates. Prestressing can also be introduced by tightening the strip.

A gap (about 10 mm to 30 mm) is surely provided between the plates and between the plates and the existing members to the extent that they do not come into contact with each other due to elasto-plastic behavior during an earthquake.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described more specifically with reference to the drawings. FIG. 1 shows an embodiment in which an existing column with a wall (sleeve wall) is subjected to seismic reinforcement according to the present invention.

In the figure, 1 is a column portion having a plurality of main muscles extending along the longitudinal direction of the construct and a plurality of girdles arranged so as to surround these main muscles, 2 is a number of transverse muscles, It is a wall portion (seismic wall or sleeve wall) that has vertical lines and is connected to the column portion 1.

Further, 3 is a plate which sandwiches the pillar portion 1 and the wall portion 2 from both sides (a steel plate or the like can be used, and the existing members such as a beam and the like are in mutual contact due to elasto-plastic behavior during an earthquake. 4 is a binding member that penetrates the plate 3 together with the wall portion 2 (PC steel rod, new material rod, etc.), 5 is the plate 3 and the pillar portion 1, the wall portion 2
It is concrete (non-shrinkable concrete or expansive concrete) or mortar (non-shrinkable mortar or expansive mortar) that has been reinforced in the gap formed between.

To provide the above-mentioned reinforcement, first, referring to FIG.
As shown in FIG. 3, through holes are formed in the wall portion 2 and the plate 3 respectively for the binding members 4 to pass through, and the plate portion 3 is arranged so as to sandwich the wall portion 2 together with the pillar portion 1 from both sides. A simple formwork 6 for temporarily fixing the wall portion 2 with the binding member 4 and connecting the width end of the plate 3 and the wall portion 2 is arranged.

Then, concrete or mortar is additionally hammered into the gap formed between the plate 3 and the pillar portion 1 and the wall portion 2, and after hardening, the simple form 6 is removed and the binding member 4 is tightened. Introduce stress.

By arranging a plate such as a steel plate,
It is possible to significantly increase the resistance to shearing force, and the structure is constructed by the passive lateral restraint effect (passive lateral restraint effect is defined as the restraint reaction force generated when concrete expands). The toughness can be improved, and the horizontal proof stress can be increased to some extent.

According to the present invention, when the seismic reinforcement as shown in FIG. 1 is applied, the cross-sectional area of the wall including the column can be increased, and the column with the wall is prestressed on the entire surface thereof. Therefore, active lateral restraint effect (active lateral restraint effect is defined as restraint force added like hydrostatic pressure from the beginning regardless of expansion of concrete structure) can be expected. Extrusion and peeling,
Large horizontal shear strength and high toughness are secured while avoiding peeling.

When the concrete or mortar is overcast, the pillar portion 1 and the wall portion 2 have the same thickness (having a rectangular cross section).

The binding members 4 are basically arranged at equal intervals, but in order to secure the strength of the column portion 1, as shown in FIG.
It is preferable that the arrangement interval W along the width direction of the wall portion 2 be close in the region near the column portion 1, which results in an effective and economical arrangement. Further, as to the arrangement interval L of the wall portion in the direction along the vertical direction, it is preferable that the wall portion is dense in its vicinity including the head and legs of the column with the wall, as shown in FIG. However, the sum of the product of the axial cross-sectional area of the binding member and the yield point strength minus the tensile stress due to prestress is the cross-sectional area of the plate length or width, whichever is smaller, and its yield point strength. It is desirable to arrange the binding members so that the product is approximately equal to or greater than the product.

It is desirable that the tension level applied to the binding member 4 should be 1/2 or less of the yield strength thereof as a standard.

A steel plate (cut steel plate) can be applied to the plate 3, and its thickness is about 3.2 to 9 mm. When the binding member 4 is a PC steel rod, its diameter is about 9 to 25 mm. Any thing can be used.

FIGS. 5 and 6 are horizontal cross-sections showing an example of seismic reinforcement of a column with a wall having a wall portion 2 (shock-resistant wall) between two column portions 1. By applying such seismic reinforcement, the strength and toughness of the column with walls are significantly improved.

When there is a concern that the weight of the structure will increase due to the additional overfilling of concrete (or mortar) or when partial reinforcement is sufficient, the size of the plate 3 and the size of the plate 3 as shown in FIGS. The arrangement area may be changed appropriately. By appropriately changing the size of the plate 3, the additional striking width and length of concrete and mortar also change, which has the advantage of controlling the yield strength, rigidity, and deformability of the column with walls.

As shown in FIG. 9, the binding member 4 can be arranged by penetrating the column portion 1, and FIG. 10 (a).
As shown in (b), the strip plate 7 (thickness around 20 mm) protruding beyond the pillar portion 1 (or plate 3) on the plate 3
It is also possible to place them on top of each other and to install them between the end portions, and by tightening the strip plate 7, higher prestress is introduced in the pillar portion 1 and the strength of that portion is further enhanced. Become.

Further, the column with the wall in which the wall portion 2 is biased with respect to the column portion 1 is reinforced in the manner shown in FIGS. 11 and 12.

FIGS. 13 (a) and 13 (b) show an example in which an RC column with a sleeve wall is permanently and temporarily reinforced. Prestress can also be introduced into such a structure by tightening the binding member 4, and in the case where it is necessary to significantly increase the bending strength particularly in the column with the sleeve wall, it is shown in FIG. When filling concrete (or mortar) as described above, it is preferable to arrange a required number of main bars (rebars) 8 by using post-installed anchors or the like.

In FIGS. 13 and 14 shown above, an example in which the wall portion 2 and the pillar portion 1 are all surrounded by the plate 3 is shown, but as shown in FIGS. 15 (a) and 15 (b), the pillar portion 1 and the wall portion are shown. No. 2 is sandwiched from both sides and the concrete is overstripped, or the wall portion 2 as shown in FIGS. 15 (c) and 15 (d).
Of course, it is also possible to leave a part of the above and sandwich it from both sides to reinforce the concrete to introduce prestress, and this point is not limited.

The present invention can also be applied to partial reinforcement of an existing column with a wall, and an embodiment in the case of partially reinforcing a column with a waist wall is shown in FIGS. 16 and 17 (a). ) (B)
Shown in.

FIG. 16 is an external perspective view of a column with a waist wall,
17 (a) and 17 (b) are an elevation view and a horizontal sectional view thereof.

In order to partially reinforce the column with the waist wall, the plate 3 is arranged at the portion to be reinforced and the column portion 1 and the wall portion 2 are sandwiched, and the plate 3 is attached to the wall portion 2 as the binding member 4. Temporarily stop. And the plate 3 and the pillar portion 1,
The space formed between the wall portions 2 is filled with concrete (or mortar), double-pressed, and after hardening, the binding member 3
Tighten up to introduce prestress.

As a result, the pillar portion 1 and the wall portion 2 are integrated, so that the strength is further enhanced.

16 and 17, reference numeral 9 is a plate such as a cut steel plate arranged on two opposite surfaces of the pillar portion 1, 10 is a corner piece, and 11 is a binding member, and the plate 9 is a pillar. It is possible to introduce the prestress while crimping the plate 9 to the pillar portion 1 by applying the corner piece 10 from above the portion 1 and tightening the corner piece 10 with the binding member 11 after applying the corner piece 10 to the portion 1. As a result, it becomes possible to reinforce only the column portion 1 (improvement in seismic performance and support capacity for vertical load).

Although FIGS. 16 and 17 show the case where the plate 9 is provided on the two surfaces of the pillar portion 1, it may be provided on the entire circumference (four surfaces) as shown in FIG. 18 (a). You can
It may be provided on three surfaces as shown in FIG.
Alternatively, the head part or the leg part of the pillar portion 1 has only two surfaces, 3
It may be provided on four surfaces or four surfaces, and this point is not limited. When the plate 9 is provided, it is important to provide a gap so that the plates 9 do not come into contact with each other due to elasto-plastic behavior during an earthquake or the plate 9 does not come into contact with an existing member such as a beam.

To reinforce only the pillar portion 1, a through hole is provided in the wall portion 2 along the pillar portion 1, and the corner piece 10 is attached through the binding member 11 through the through hole. FIG. 19 shows an example in which the plate 9 is provided on the two opposite surfaces of the pillar portion 1, the corner piece 10 is arranged at the corner portion and tightened by the binding member 11 to introduce prestress, and the wall portion 2 is the pillar portion. FIG. 20 shows an example in which a column with a wall that is biased with respect to No. 1 is reinforced by a corner piece 10, a strip plate 7, and a binding member 11.

Prestressing can be introduced in the same manner as shown in FIG. 21 for a column with a wall in which a wall portion 2 such as a waist wall or a hanging wall is biasedly connected to a column portion 1.

The plate 3 can be brought into direct contact with the pillar portion 1, but in order to further strengthen the pillar portion 1, it may be arranged via concrete (or mortar) as shown in FIG. Good.

If it is possible to mount it on site, the plate 3 may be processed into a U-shape and welded at its abutting surface as shown in FIG.

In the embodiment of the present invention, the pillar portion 1 is shown as an example having a square cross section, but it may have a circular cross section. In this case, FIG.
As shown in Fig. 24, the plate 3 that comes into contact with the pillar portion is processed so as to be along the surface thereof, or as shown in Fig. 24 (b), a flat plate is put so as to come into contact with the circular cross section, and concrete or mortar is placed in the gap. Fill with. Further, when the pillar portion 1 and the wall portion 2 are connected at an angle, the plate 3 may be arranged so as to match the angle, and this point is not particularly limited.

When it is permissible to increase the thickness of the plate 3, as shown in FIGS. 25 (a) and 25 (b), the plate 3 is directly pressure-bonded to the wall portion 2 by the binding member 4. It can be tightened, in this case, for the pillar part 1,
It may be reinforced in the manner shown in FIG.

[0046]

EXAMPLES Example 1 A column with a sleeve wall as shown in FIGS. 26 (a) and 26 (b) (column portion:
Width 250 mm, width 250 mm, height 1000 mm, pillar part (sleeve): width 250 mm, thickness 50 mm, height 1000 m
m), and a thickness of 3.2 m as shown in FIGS.
PC steel rods (2 rows of 16 on each side) that are m and have a vertical dimension of 970 mm (give a gap of 15 mm between the plate and the beam), and sandwich them with steel sheets with a horizontal dimension of 750 mm to fill the concrete and harden it to a diameter of 5.4 mm. ), A prestress of 490 MPa (strain 2450 μm) was introduced. Then, with respect to the column with the sleeve wall, the horizontal proof stress fluctuation state (shear force V (kN) when the upper beam is repeatedly moved in the horizontal direction in the state where axial compressive stress (axial force ratio 0.2) is applied. ) And the interlayer deformation angle R (relationship between (horizontal movement amount / height) × 100%)). The result is shown in FIG.
It shows in comparison with (b). This examination corresponds to a reduced model of a standard structure of about 1 / 2.6. Further, the axial force ratio 0.2 is a load corresponding to the loaded load and its own weight, which corresponds to 20% of the concrete compressive strength.

Column portion (common to FIGS. 26 and 27) Main bar: 12-D10 (main bar ratio Pg = 1.36%) Strap: 3.7φ-pitch 105 mm (shear reinforcement ratio Pw)
= 0.08%) Concrete compressive strength σ _B : 25.7 MPa Axial force ratio (N / (bDσ _B )): 0.2 (N: axial force,
b: Width of column, D: blame of column) Shear span ratio (M / (VD)): 2.0 Sleeve wall part: Horizontal line and vertical line: 3.7φ-pitch 105 mm (single)

As is clear from FIGS. 28 (a) and 28 (b),
In the structure shown in FIG. 27 reinforced according to the present invention, it was confirmed that the horizontal shearing force V is constant regardless of the variation of the interlayer deformation angle R, and that the horizontal proof strength is hardly deteriorated.

Example 2 PC steel rods (two rows on each side, 6 pieces) sandwiched by steel plates having a thickness of 3.2 mm, a vertical dimension of 500 mm, and a horizontal dimension of 750 mm, and concrete was filled in the gap and hardened to have a diameter of 5.4 mm. At 49
Pre-stress of 0 MPa (strain 2450 μm) was introduced to locally reinforce and cut steel plate (2
40 × 470 × 3.2mm) with 4 sides, and corner pieces (pitch 41mm, 11 rows arranged) with a diameter of 5.
A column with a waist wall as shown in Fig. 29 (waist wall: thickness 50 mm, in which PC steel rods to be 4 mm are arranged at a pitch of 41 mm and prestress is also introduced (490 MPa) into the column portion and a cut steel plate is crimped. , Vertical size 500mm, horizontal size 800mm (one side), vertical and horizontal lines: 3.7φ-pitch 105mm single)
Was placed between the beams (stubs) and the same examination as in Example 1 was performed. The result is shown in FIG. 31 together with the result of a column with a waist wall as shown in FIG. 30 (the waist wall portion is not reinforced, and the column portion is reinforced as in FIG. 29 except for the cut steel plate).
Shown in (a) and (b).

Columns (common to FIGS. 29 and 30 except for the cut steel plate) Main bars: 12-D10 (Pg = 1.36%) Strips: 3.7φ-pitch 105 (Pw = 0.08%) Concrete Compressive strength: 20.6 MPa Axial force ratio: 0.2 Waist wall part: Lateral and vertical lines: 3.7φ-pitch 105 mm (single)

As is apparent from FIGS. 31 (a) and 31 (b), the column with wall shown in FIG. 29, which is reinforced according to the present invention, is
Compared to the column with a wall shown in FIG. 30, the shearing force V is almost constant, the value is large, the horizontal proof stress is hardly deteriorated, and the degree of damage even when the interlayer displacement angle R reaches 5%. Was very few. On the other hand, in the reinforcement as shown in FIG. 30, a large breakage (shear break) was observed in the middle of the first cycle toward the interlayer displacement angle R = 2.0%.

[0052]

According to the present invention, not only can the seismic performance of the existing column with walls be maintained at a high level permanently, but even if it is damaged by an earthquake, etc. It becomes possible to reinforce.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a prestress introduction procedure.

FIG. 3 is a diagram showing an arrangement interval of the connecting members.

FIG. 4 is a diagram showing the arrangement intervals of the connecting members.

FIG. 5 shows a horizontal section of a walled column reinforced according to the present invention.

FIG. 6 shows a horizontal section of a walled column reinforced according to the invention.

FIG. 7 shows a horizontal section of a walled column reinforced according to the invention.

FIG. 8 shows a horizontal section of a walled column reinforced according to the invention.

FIG. 9 shows a horizontal section of a walled column reinforced according to the invention.

10 (a) and 10 (b) are views showing a horizontal cross section and a side surface of a column with a wall reinforced according to the present invention.

FIG. 11 shows a horizontal section of a walled column reinforced according to the invention.

FIG. 12 is a view showing a horizontal section of a column with a wall reinforced according to the present invention.

13 (a) and 13 (b) are views showing a horizontal cross section of a column with a wall reinforced according to the present invention.

FIG. 14 shows a horizontal section of a walled column reinforced according to the invention.

15 (a) to 15 (d) are views showing horizontal cross sections of columns with walls reinforced according to the present invention.

FIG. 16 is an external perspective view of a column with a wall reinforced according to the present invention.

17 (a) and (b) are views showing the elevation and horizontal cross section of FIG.

18 (a) and 18 (b) are views showing another example of a column with a wall reinforced according to the present invention in a horizontal section.

FIG. 19 is an external perspective view of a walled column reinforced according to the present invention.

FIG. 20 is an external perspective view of a column with a wall reinforced according to the present invention.

FIG. 21 is a view showing another example of a column with a wall reinforced according to the present invention in a horizontal section.

FIG. 22 is a view showing another example of a column with a wall reinforced according to the present invention in a horizontal section.

FIG. 23 is a view showing another example of a column with a wall reinforced according to the present invention in a horizontal section.

FIGS. 24 (a) and 24 (b) are views showing another example of a column with a wall reinforced according to the present invention in a horizontal section.

25 (a) and (b) are views showing an example of reinforcement of a column with a wall.

26 (a) and (b) are views showing an elevation and a horizontal cross section of a column with a wall used in Examples.

27 (a) and (b) are views showing an elevation and a horizontal cross section of a column with a wall used in Examples.

28 (a) and 28 (b) are shear force V and interlayer deformation angle R.
It is a graph showing the relationship of.

FIG. 29 is an external perspective view of a column with a wall used in an example.

FIG. 30 is an external perspective view of a column with a wall used in an example.

31 (a) and 31 (b) are shear force V and interlayer displacement angle R.
It is a graph showing the relationship of.

[Explanation of symbols]

1 pillar part 2 walls 3 plates 4 binding members 5 Concrete or mortar 6 Simple formwork 7 strip 8 main lines 9 plates 10 corner pieces 11 Binding members

Claims (11)

[Claims] 1. A column portion having a plurality of main bars extending along the longitudinal direction of the construct and a plurality of stirrups arranged so as to surround these main bars, and a plurality of transverse bars and vertical bars. For the existing walled pillar that consists of a wall part that is internal and connected by at least a part of the pillar part, at the time of applying permanent and temporary seismic reinforcement, at least two plates facing each other are used to connect the wall part. After sandwiching the pillar part together, after temporarily fixing the plate with a plurality of binding members penetrating with the wall part,
Concrete or mortar is strengthened by strengthening concrete or mortar in the gap formed between the plate and the pillar portion and the wall portion, and then the binding member is tightened to introduce prestress. Permanent, temporary seismic reinforcement method. 2. A binding member in which plates are arranged on the entire height of the column portion, or on the entire circumference of the column head and column legs, on two or three surfaces facing each other, and corner pieces are arranged on the corners. The method according to claim 1, wherein the plate is crimped to the column portion while tightening the corner piece to introduce prestress. 3. The method according to claim 1, wherein the wall portion is a seismic wall, a waist wall, a hanging wall or a sleeve wall. 4. The yield strength, rigidity, and deformability are controlled by adjusting the length and width of concrete or mortar to be overstripped by changing the size and arrangement area of the plate. The method described. 5. The plate is directly arranged on the pillar portion and the wall portion using a corner piece or a strip plate, and the plate is crimped while introducing prestress by tightening the binding member. The method according to any one. 6. The method according to claim 1, wherein the reinforcing bars are arranged in advance in the gaps formed between the plate and the pillar portion and the wall portion by post-installed anchors or the like. 7. The method according to claim 1, wherein the binding members are arranged at intervals along the width direction and the longitudinal direction of the wall portion. 8. The method according to any one of claims 1 to 7, wherein the arrangement intervals of the binding members along the width direction of the wall portion are close in the region near the column portion. 9. The arrangement according to claim 1, wherein the binding members are arranged at intervals along the longitudinal direction of the wall portion in the vicinity thereof including the head portion and the leg portion of the column with the wall. The method described. 10. A strip plate projecting beyond an edge of the plate is superposed on at least two plates arranged to face each other, and the strip plate is provided by a binding member penetrating between the strip plates. The method according to any one of 1 to 9, wherein the method is tightened to introduce prestress. 11. The method according to claim 1, wherein gaps are provided between the plates and between the plates and the existing members to the extent that they do not come into contact with each other due to elasto-plastic behavior during an earthquake.