JP3703204B2 - Seismic reinforcement method for existing buildings - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for repairing an existing building having insufficient seismic performance to one having sufficient seismic resistance, and in particular, a structure in which the upper structure of the building is supported via a seismic isolation bearing. The present invention relates to a seismic reinforcement method for existing buildings.
[0002]
[Prior art]
Most existing buildings are designed to have seismic performance based on predetermined standards. However, the design standards for buildings have been reviewed several times in the past, and the earthquake resistance has been revised to be stricter. For this reason, some designed based on the old standards have structural weaknesses such as lack of column reinforcement in light of the current standards. Such buildings can be damaged by large earthquakes. On the other hand, it is almost impossible to immediately rebuild all existing buildings that lack earthquake resistance, and methods for improving earthquake resistance by renovation are being considered. For example, a method of reinforcing a column from the outside or a method of reinforcing an entire structure by adding an oblique member or the like has been proposed.
[0003]
[Problems to be solved by the invention]
However, the method for reinforcing the entire structure or the structural member as described above has the following problems.
When a member is added to the upper structure or a column member is reinforced, the renovation work covers a wide range of the building and requires a large amount of cost, and the appearance of the building is significantly impaired. For this reason, the function as a building will fall or a value will decrease.
[0004]
The present invention has been made in view of the above problems, and its purpose is to provide a seismic reinforcement method for existing buildings that can greatly improve the earthquake resistance of existing buildings by safe and simple renovation work. Is to provide.
[0005]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, in the seismic reinforcement method for an existing building according to claim 1, a step of attaching brackets at two upper and lower portions of a pillar of the building, and the brackets attached at two upper and lower portions A temporary support jack is interposed between the bracket and at least a part of the reaction force of the jack is borne on the bracket, and a load acting on the column is supported by the temporary support jack; and two brackets are attached. A step of excising the column between positions, a step of inserting a base isolation support and a column end support jack on top of each other in a portion where the column is excised, and operating the column end support jack, a step but to support the load to bear on the seismic isolation bearing, said a seismic reinforcement method for existing buildings and a step of removing the temporary support jacks and the bracket, the bracket attached to the two positions is Is intended to be attached to become floors, it is intended to include the step of providing a through hole for inserting the temporary support jacks or provisional posts to the floor plate to be present between the two brackets.
[0006]
According to a second aspect of the present invention, in the method for seismic reinforcement of an existing building according to the first aspect, the step of attaching the bracket comprises: abutting two steel members against two opposite side surfaces of the column; The two steel members are connected to each other by a PC steel material disposed on the steel plate, and the steel member is pressed against the column side surface by introducing a tension force to the PC steel material.
[0007]
The invention according to claim 3 is the seismic reinforcement method for an existing building according to claim 1, wherein the step of attaching the bracket to the side surface of the column is formed by drilling a hole in the side surface of the column and attaching a cap nut to the hole. The bracket is fixed by a bolt that is embedded and screwed into the cap nut.
[0008]
According to a fourth aspect of the present invention, in the seismic reinforcement method for an existing building according to the first aspect, an end plate arranged in a horizontal direction and a vertical start from the end plate surround the side surface of the column. An end reinforcing member provided with a standing plate provided on the column is attached to the end of a column with a part cut away, and a filler is provided between the column end surface in the standing plate and the end plate. A step of filling and curing is included.
[0009]
The invention according to claim 5 includes the step of connecting an end portion of the existing building after excising a part of the column with an adjacent column with a beam or a floor slab. Shall be.
[0010]
The seismic reinforcement method for an existing building having the above-described configuration can be applied to any building of reinforced concrete, steel frame, and steel reinforced concrete. And each process of Claim 1 is performed about all the pillars of one building, may be performed sequentially about each pillar, and it is made into a set of plurals. It may be divided and sequentially performed, or may be performed all at once for all the pillars.
[0011]
The column end supporting jacks installed over the seismic isolation bearings are used permanently after refurbishment, and it is desirable that the jack stroke be fixed. For example, it is a jack having a structure for supporting a load by using fluid pressure, and a hardened material such as a resin is used as a fluid.
[0012]
[Action]
Since the invention according to the present application includes the above-described steps, it operates as follows.
In the seismic reinforcement method for an existing building according to claim 1, brackets are attached to the upper and lower portions of the column, and the load borne by the column is supported by the temporary support jack interposed between them. It is possible to cut the column between the two brackets. At this time, since at least a part of the reaction force of the temporary support jack is borne by the bracket, a large load does not act on the beam joined to the column, and it is sufficient even if there is a load due to the use of the building Safety is maintained.
[0013]
In addition, the brackets attached to the upper and lower two places are attached to different floors of the building. Temporary struts and jacks that support the load acting on the pillars between these brackets are connected to the floor slabs on the floor between them. Because it is arranged with support, it supports the axial force of the column without applying any load to the beam on this floor, and cuts off a part of the column at a portion close to the upper surface or the lower surface of the beam on this floor Can do. And a seismic isolation bearing can be arranged in this part to make a seismic isolation structure.
[0014]
In addition, after part of the column is excised, the column end support jack is inserted into this part together with the seismic isolation bearing, so the stroke of this jack is adjusted and the load borne by the temporary support jack is It can be transferred to an end support jack. At this time, the load of the load can be transferred without pushing up the pillar above the excised part, so even if the above process is performed on some pillars of one building, In this case, no additional stress acts, and the safety of each member is maintained.
Therefore, seismic isolation bearings can be installed sequentially for each pillar, and can be repaired with small-scale construction. In addition, the safety during the renovation work is improved, and the renovation while using the building is also possible.
[0015]
As described above, the seismic isolation bearings are inserted into all the columns, so that relative displacement is allowed between the upper part and the lower part, and the seismic force transmitted to the upper part is reduced. Further, a damping force or a restoring force can be applied by appropriately designing the seismic isolation device or by attaching an appropriate device between the upper part and the lower part.
[0016]
In the seismic reinforcement method for an existing building according to claim 2, the steel bracket is fastened by PC steel arranged outside the cross section of the column and fixed by pressing strongly to the side of the column, so that the cross section of the column is penetrated. There is no need to provide a mouth or the like, and there is no defect in the column section. Accordingly, the bracket can be safely attached even to a reinforced concrete / steel reinforced concrete column or a steel column that has a margin in cross section.
[0017]
In the seismic reinforcement method for an existing building according to claim 3, the bracket is fixed with a bolt screwed into a cap nut inserted into the column. The bolt can be fixed, and the force acting on the bracket is transmitted to the column by the shearing force of the bolt.
[0018]
In the seismic reinforcement method of the existing building described in Claim 4, an end plate is arrange | positioned so that it may become horizontal in opposition to the cut surface of a column, and the standing board raised from this end plate is a column edge part. Since it is attached so that it surrounds, the end part reinforcement | strengthening when part of concrete pillars are excised is performed effectively. Therefore, safety against splitting or the like is sufficiently ensured when the base-excluded support is inserted into the part where the column is cut to support the axial force of the column.
[0019]
In the seismic reinforcement method for an existing building according to claim 5, since the end portion after the part of the column is excised is connected to the adjacent column with a beam or a floor slab, On the other hand, it is possible to prevent the cross-sectional force of the column from becoming excessive. In addition, the seismic isolation device can be effectively protected against fire and the like.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1, FIG. 2 and FIG. 3 are schematic views showing each step of the seismic reinforcement method for an existing building, which is one embodiment of the present invention.
This method is carried out in the following steps.
[0021]
First, as shown in FIG. 1 (a), two brackets 4 and 5 are fixed to the pillar 1b of the lower floor portion of the existing building and the pillar 1a of the upper floor portion thereof, and the floor slab of the floor of the immediately upper floor is fixed. 2 is provided with a through hole, and the temporary support jack 6 and the temporary support column 7 are inserted between the upper and lower brackets. Then, a load is introduced into the jack 6 so that the axial force acting on the column 1 a is borne on the temporary support jack 6 and the temporary support 7. Thereby, it can be set as the state from which the axial force hardly acts on the pillar 1a between the two brackets 4 and 5. FIG. The pillar 1 of this building is made of reinforced concrete, and the brackets 4 and 5 have a structure as shown in FIG.
The bracket 4 has four steel members 41, 42, 43, 44 that are in contact with the four side surfaces of the column 1, and the opposing steel members are arranged along both side surfaces of the column 1. It is connected and tightened by the PC steel material 45. As a result, the steel member is strongly pressed against the side surface of the column 1 and is fixed to the column.
[0022]
The four steel members 41, 42, 43, 44 are overlapped with other steel members adjacent to each other at their ends, and are overlapped in the form of a cross-beam surrounding the column 1, and adjacent in the vertical direction. It can be transmitted to the member.
As shown in FIG. 5, each of the steel members is constructed so that plate members are assembled in a horizontal direction and a vertical direction by welding and have sufficient rigidity and strength. And the unevenness | corrugation is provided in the surface pressed against the column side surface of the steel member 41 in order to prevent sliding in a perpendicular direction, and it is about 20 mm in thickness between this steel member and the column side surface. High strength mortar 46 is filled.
As the irregularities, for example, those having irregularities in a net shape as shown in FIG. 6 or those obtained by welding wires in the vertical and horizontal directions as shown in FIG. 7 can be adopted. Depending on the state of the side surface of the column, the steel member may be directly pressed against the side surface of the column without using the high-strength mortar.
[0023]
When the axial force acting on the column 1 as described above is borne by the temporary support column 7 and the temporary support jack 6 via the brackets 4 and 5, for example, as shown in FIG. Cut out the upper pillar of the floor. The column can be cut by cutting concrete, reinforcing bars, and steel frames using, for example, a diamond cutter.
[0024]
At this time, the corner of the end of the cut column is easy to break, and if the column is supported by the seismic isolation bearing, a horizontal tensile force is generated at the end of the column by a reaction force, and the end is It becomes easy to break. In order to prevent this, it is desirable to reinforce the end portion, and the reinforcement can be performed as shown in FIG.
This reinforcing method uses an end reinforcing member 8 having an end plate 81 arranged in the horizontal direction and an upright plate 82 raised from the end plate 81 in the vertical direction. Is provided so as to surround the end of the pillar 1. In addition, a plurality of stud gibbles 83 are attached to the upper surface of the end plate 81, and are superposed on the rebar 1c left uncut so as to protrude from the end surface of the column 1, and a non-shrinkable high-strength mortar 84 is interposed therebetween. Filled.
In addition, depending on the magnitude | size of the load which acts on a pillar, as shown in FIG. 9, the standing board of the said edge part reinforcing material can be abbreviate | omitted. In addition, as shown in FIG. 10, the reinforcing bar 1 c may be directly welded to the upper surface of the end plate 85 without providing the stud gibber.
[0025]
FIG. 11 is a diagram showing another example of the method of attaching the end reinforcing member, and the end reinforcing member 86 used in this method is similar to that shown in FIG. However, the standing plate 88 is provided so as to create a gap between the side surface of the pillar 1. Then, as shown in FIG. 11 (a), an uncured epoxy resin 89 is put inside a standing plate 88 in the shape of a container, and this is fitted to the end of the pillar 1, and FIG. 11 (b). As shown in FIG. 5, an epoxy resin is filled between the end plate 87 and the end surface of the column 1 and between the standing plate 88 and the column side surface to be cured. In addition, it can replace with the said epoxy resin and can handle in liquid form, such as other resin and a cement-type grout material, and what hardens | cures and has big intensity | strength can be used.
[0026]
When the column is cut and the end portion is reinforced as described above, the seismic isolation bearing 9 and the flat jack 10 are inserted into the cut portion as shown in FIG.
As shown in FIG. 12, the seismic isolation bearing 9 prevents steel plates 91 and 92 disposed above and below, a rubber material 93 disposed therebetween, and excessive deformation of the rubber material 93 from occurring. In order to do this, a main part is composed of a plurality of reinforcing plates 94 embedded in the rubber material 93 in the horizontal direction and a lead columnar member 95 embedded in the center of the rubber material 93. In such a seismic isolation bearing 9, the rubber material 93 supports a load in the vertical direction, and the deformation of the rubber material 93 allows a horizontal relative displacement to occur between the upper and lower steel plates 91 and 92. The lead columnar member 95 gives a damping force to the relative motion between the upper and lower steel plates.
In addition, seismic isolation bearings are not limited to the above structure, but support the load in the vertical direction by inserting spheres and cylinders on the upper and lower steel plate surfaces, and fix the rails to the upper and lower steel plates, respectively. In addition, they are arranged so that they are perpendicular to each other, and seismic isolation bearings of various structures, such as an intermediate support that can roll or slide along both of these rails, can be used. .
[0027]
The main part of the flat jack 10 is made of a steel bag-like member, and a fluid can be press-fitted into the inside. This bag-shaped member is formed flat and has a circular shape, a square shape, an oval shape, or the like. When a fluid is pressed into the bag-like member, the gap between the bag-shaped upper and lower plates is pushed. The upper structure can be pushed up and the load from the upper structure can be borne. In addition, the upper structure can be permanently supported by selecting a fluid to be pressed and hardened without shrinkage. In this embodiment, an uncured epoxy resin is used as the fluid.
[0028]
The press-fitting of the epoxy resin into the flat jack 10 is performed by using a press-in pump 11 as shown in FIG. 2B or 12, whereby the flat jack 10 expands in the vertical direction and acts on the column 1. To bear the load of the superstructure. In this state, the pressure inlet of the flat jack 10 is sealed, the epoxy resin is cured, and the load of the upper structure is permanently supported by the seismic isolation support 9. As a result, the temporary support column 7 and the temporary support jack 6 are not loaded, and the brackets 4 and 5 can be removed, and the column ends are supported by the seismic isolation bearing 9 as shown in FIG. It can be set as a structure.
[0029]
By performing this process for all pillars on the same floor of the building, the entire superstructure of the building is supported by seismic isolation bearings, reducing the horizontal force transmitted to the superstructure during an earthquake. Therefore, it can be made a structure with less vibration and excellent earthquake resistance.
In addition, in general, the first floor is suitable for the seismic isolation support, but depending on the structure of the building, it may be inserted in the basement, or two or more upper floors. It may be inserted in the floor.
[0030]
FIG. 13 is a schematic view showing another embodiment of the invention according to the present application. FIG. 13 (a) shows a seismic isolation bearing provided at the top of the lower floor pillar 1a, that is, immediately below the beam 3a on the upper floor. It will be seismically isolated. In this case, the brackets 104 and 105 are provided on the upper floor and the lower floor, and the temporary support column 107 and the temporary support jack 106 are interposed between them, and the existing building is exempted in the same manner as in the above embodiment. It can be quake.
In addition, FIG.13 (b) is a figure which shows the earthquake-proof reinforcement method of the existing building which can be implemented as an application of this invention, Comprising: A seismic isolation support is provided in the intermediate part of the pillar 1a of a specific floor. Is. In this seismic reinforcement method, the brackets 204 and 205 are attached to the upper and lower portions of the column 1a of the target floor portion, and the load of the column 1a is applied to the temporary column 207 and the temporary support jack 206 without providing a hole penetrating the floor slab. Can be supported. And an existing building can be seismically isolated by the process similar to embodiment described previously.
[0031]
FIG. 14 shows an example in which a building having a sufficient margin from the floor to the ceiling of the first floor portion is seismically isolated by inserting a seismic isolation bearing at the lower end of the column of the first floor portion.
In this embodiment, the seismic isolation bearing 309 is inserted into the lower end of the column 1 on the first floor in the same process as the seismic reinforcement method shown in FIGS. After this is done for all the columns, a beam 303 and a floor slab 302 are provided so as to be joined to the upper part of the part to which the seismic isolation bearing 309 is attached, that is, the end part where the part of the column 1 is cut off. It forms the floor. In such a seismic reinforcement method, the newly provided floor and the original first-floor beam 3 and floor slab 2 are seismic isolation floors that allow relative displacement in the horizontal direction, and the lower end of the column 1 is the beam 303. -It is connected by the floor slab 302, and it is possible to prevent a large cross-sectional force from being generated in the column 1 even when a horizontal force is applied during an earthquake. Even in the event of a fire, the seismic isolation bearing is protected by the existing floor slab 2 and the newly installed floor slab 302, and fire resistance is improved.
[0032]
The embodiment described above is a case where the column is reinforced concrete or steel reinforced concrete, but the case where the column is a steel frame can also be made a seismic isolation structure by inserting a seismic isolation support through a similar process.
FIG. 15 is a front view, a side view, and a plan view showing a state where the bracket 404 is attached to the steel pillar 401. The bracket 404 used here has the same shape as the bracket shown in FIG. 4, but the steel column 401 can be easily provided with a through hole as compared with concrete, and is a PC for fastening a steel member. It can also arrange | position so that some steel materials may penetrate the cross section of a pillar.
[0033]
In addition, FIG. 16 can also be provided with a plurality of bolt holes in the steel column 501 and the bracket 502 can be fixed by bolts 503 inserted therethrough. FIG. 16 is a schematic front view and schematic plan view showing an example thereof. is there. By fixing the bracket 502 with the bolts 503 in this way, the shape and dimensions of the bracket 502 can be reduced, and can be easily attached.
On the other hand, even in the case of a reinforced concrete or steel reinforced concrete column, a bracket can be fixed with a bolt by embedding a cap nut 601 as shown in FIG. The cap nut 601 is fitted into a hole drilled in the column side surface, and a space 602 between the outer surface of the cap nut and the inner surface of the hole is filled with a material having a large adhesive force such as an epoxy resin and firmly fixed. is there.
[0034]
【The invention's effect】
As described above, in the seismic reinforcement method for an existing building according to the present invention, brackets are attached at two places above and below the pillar, and the load acting on the pillar is applied by the temporary support and the temporary support jack interposed between them. Since the seismic isolation bearing is attached while supporting, a large load does not act on the beam joined to the column, and sufficient safety can be maintained even if there is a load due to the use of the building.
In addition, once the load is applied to the temporary support column and temporary support jack and the base isolation support is inserted, the column load is transferred to the state in which the base isolation load is supported without lifting the column upward. Therefore, even if the work for inserting the seismic isolation bearing is performed sequentially for each column, no additional stress acts on the beam or the column, and the safety of each member is maintained. Therefore, it can be repaired by small-scale construction, and it can also be repaired to a seismic isolation structure while using the building.
Furthermore, brackets can be attached to different floors, and temporary struts and temporary support jacks can be arranged by providing through holes in the floor slab, and seismic isolation bearings can be inserted at arbitrary positions on the pillars.
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a schematic diagram for explaining each step of a seismic reinforcement method for an existing building which is an embodiment of the invention according to the present application.
FIG. 2 is a schematic diagram for explaining each step of the seismic reinforcement method for an existing building which is an embodiment of the invention according to the present application.
FIG. 3 is a schematic diagram for explaining each step of the seismic reinforcement method for an existing building which is an embodiment of the invention according to the present application.
4 is a front view, a side view, and a plan view of a bracket used in the method described in FIGS. 1 to 3. FIG.
FIG. 5 is a cross-sectional view of the bracket shown in FIG.
6 is a schematic view showing a contact surface with a column of the bracket shown in FIG.
7 is a schematic view showing a contact surface with a column of another bracket that can be used in place of the bracket shown in FIG. 4. FIG.
FIG. 8 is a schematic cross-sectional view showing a method for reinforcing an end face obtained by cutting a column in the seismic reinforcement method shown in FIGS. 1 to 3;
FIG. 9 is a schematic cross-sectional view showing another example of a method for reinforcing an end face obtained by cutting a column in the seismic reinforcement method shown in FIGS. 1 to 3;
10 is a schematic cross-sectional view showing another example of a method for reinforcing an end face obtained by cutting a column in the seismic reinforcement method shown in FIGS. 1 to 3. FIG.
11 is a schematic cross-sectional view showing another example of a method for reinforcing an end face obtained by cutting a column in the seismic reinforcement method shown in FIGS. 1 to 3. FIG.
12 is a schematic view showing the structure of a seismic isolation bearing and a flat jack used in the seismic reinforcement method shown in FIGS. 1 to 3. FIG.
FIG. 13 is a schematic view showing another embodiment of the invention according to the present application.
FIG. 14 is a schematic view showing another embodiment of the invention according to the present application.
FIG. 15 is a front view, a side view, and a plan view showing a state in which a bracket is attached to a steel column.
FIGS. 16A and 16B are a schematic front view and a schematic plan view showing another example of a bracket attached to a steel column. FIGS.
FIG. 17 is a schematic cross-sectional view showing an attached state of a cap nut for fixing a bracket to a concrete pillar using a bolt.
[Explanation of symbols]
1,401,501 Column 2 Floor slab 3 Beam 4,104,204,404 Bracket 5,105,205 Bracket 6,106,206 Temporary support jack 7,107,207 Temporary support 8 End reinforcement 9,309 Seismic support 10 Flat jack (jack for column end support)
11 Press-in pump 41, 42, 43, 44 Steel member 45 PC steel 46 High strength mortar 81, 85, 87 End plate 82, 88 Standing plate 83 Stud gibber 84 High strength mortar 91, 92 Steel plate 93 Rubber material 94 Reinforcement plate 95 Lead-made columnar member 502 Bracket 503 Bolt 601 Cap nut

Claims (5)

Attaching brackets to two places above and below the pillars of the building;
A step of inserting a temporary support jack between the brackets attached at two upper and lower positions, causing the bracket to bear at least a part of a reaction force of the jack, and supporting a load acting on the column on the temporary support jack. When,
Cutting the column between the two bracketed positions;
Inserting a base-isolated support and a column end support jack on top and bottom of the part where the column is cut;
Actuating the column end support jack to support the seismic isolation bearing with the load borne by the column;
A method for seismic reinforcement of an existing building including the step of removing the temporary support jack and bracket ,
The brackets attached to two places are attached to different floors, and include a step of providing a through hole through which a temporary support jack or a temporary support is inserted in a floor slab existing between the two brackets. Seismic reinforcement method for existing buildings. In the earthquake-proof reinforcement method of the existing building of Claim 1,
The step of attaching the bracket includes
The two steel members are brought into contact with two opposite side surfaces of the column, the two steel members are connected by a PC steel material arranged outside the cross section of the column, and a tensile force is introduced into the PC steel material to thereby remove the steel member from the column. A method for seismic reinforcement of an existing building, characterized by being pressed against the side. In the earthquake-proof reinforcement method of the existing building of Claim 1,
The step of attaching the bracket to the side of the column
A method for seismic reinforcement of an existing building, wherein a hole is drilled in a column side surface, a cap nut is embedded in the hole, and the bracket is fixed with a bolt screwed into the cap nut. In the earthquake-proof reinforcement method of the existing building of Claim 1,
An end reinforcing material comprising an end plate arranged in a horizontal direction and an upright plate that is vertically raised from the end plate and surrounds the side surface of the column. Attach to the end,
A method for seismic reinforcement of an existing building, comprising a step of filling and hardening a filler between a column end face in the standing plate and the end plate. In the earthquake-proof reinforcement method of the existing building of Claim 1,
A method for seismic reinforcement of an existing building, comprising a step of connecting an end portion after excising a part of a column with an adjacent column with a beam or a floor slab.

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