JP3775219B2 - Vibration damping structure of PC frame - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to vibration damping of a PC frame composed of a column of cast-in-place concrete or precast reinforced concrete (hereinafter referred to as “PCaRC”) structure, or a column of precast prestressed concrete (hereinafter referred to as “PCaPC”) structure and a beam of PCaPC structure. Concerning the structure, a steel damper or oil damper is installed as a damping device at the pressure-bonded joint between the pillar and the beam, where the PC steel material penetrating the joint between the pillar and the beam is fixed by the Poston tension method. It is.
[0002]
[Prior art]
As a structural frame, the columns and beams of the PCaRC structure or PCaPC structure have been joined with PC steel or high-strength steel such as high-strength bolts, and at the same time with a PC crimping method that introduces a predetermined amount of prestress into the joint. A PC crimping frame constructed in this manner is known.
[0003]
Conventional PC crimping frames are generally constructed as ramen frames (the same applies to “rigid frame”) with walls in addition to frames as seismic elements, and if necessary, absorb vibration energy of structures during earthquakes. Various damping devices and damping technologies are installed as damping devices.
[0004]
By the way, the behavior of the PC crimping frame itself during an earthquake is that, particularly in the crimping joint between the column and the beam, the crimping joint surface between the pulling side of the beam end and the column side is mutually caused by the bending moment acting on the joint. It causes a separation deformation that separates, but exhibits elastic behavior that returns to its original state when the vibration is contained.
[0005]
Therefore, the PC crimping frame has a feature that the deformation of the frame at the time of earthquake is large although the residual deformation after the earthquake is small because the absorption of vibration energy due to the plastic deformation of the member is very small. This was a problem in putting the crimping frame into practical use.
[0006]
On the other hand, various types of vibration control devices and vibration control technologies use plastic dampers that use plastic deformation of steel materials and viscous properties, using interlayer deformation on each floor of the structure and deformation differences between members such as columns, beams, and walls. The vibration energy at the time of earthquake was absorbed by the oil damper etc. using the viscous resistance of the body.
[0007]
Among these, as an apparatus using interlayer deformation on each floor of a building, for example, as shown in FIG. 6 (a), a steel damper is installed in the vicinity of the middle part in the height direction of the floor where the building is located. It has been.
[0008]
In this example, highly rigid members (hereinafter referred to as “rigid members”) 30 and 31 are arranged on the upper floor and the floor, respectively, and a steel damper 32 is installed between the rigid members 30 and 31. And if a building shakes, a deformation difference will arise between the said floor and the upper floor, and the deformation difference will be collected by the steel damper 32 via the rigid members 30 and 31 which hardly deform | transform, and this steel damper 32 will be By being plastically deformed, the vibration energy of the building is absorbed.
[0009]
As an apparatus using deformation between members, for example, an apparatus in which a steel damper 32 is installed in the vicinity of the center of the beams 33, 33 as shown in FIG. 6B is known. In this example, one end side of each of the beams 33 and 33 is joined to the column 34, and the other end side is joined to each other via the steel damper 32.
[0010]
And if a vibration generate | occur | produces in a building, the deformation | transformation of an up-down direction will arise in the beam edge part by the side joined by the steel damper 32 by the junction part of the pillar 34 and the beam 33 rotating. As a result, as in the previous example, the steel damper 32 is plastically deformed to absorb the vibration energy of the building.
[0011]
In the above-described two examples, a steel damper 32 is replaced with an oil damper or the like (not shown) using a viscous material.
Furthermore, conventional PC crimping methods are limited to those using bonded PCs, and those using unbonded PCs are not generally employed.
[0012]
[Problems to be solved by the invention]
Conventional PC crimping frames have a problem that, when they are largely deformed during an earthquake, they have a large elastic resilience and a small residual deformation, but on the other hand, they have a poor energy absorption capability due to the deformation history of the frame.
[0013]
Secondly, when installing a damping device, it is extremely important to select an installation location because it is necessary to prevent as much as possible the torsional deformation of the building that adversely affects the building. In addition, since many of the conventional damping devices require a large space around the installation part, there are sometimes problems such as being severely restricted from the aspect of the architectural plan to the installation place in a plane and elevation. It was.
[0014]
Thirdly, as the deformation difference of each part of the frame to be introduced into the attenuation device, the conventional method directly uses the interlayer deformation, etc., but the deformation difference introduced into the attenuation device is optimized for the attenuation device and its effect. There was no particular control to do.
[0015]
Fourth, bond PC is generally used for PC crimping frames, and there is a risk that the beam member will fall off or rotate in the event of breakage of PC steel due to delayed fracture in unbond PC crimping. There were safety issues.
[0016]
The present invention has been made to solve the above problems, and provides a vibration damping structure for a PC frame that has a very large vibration energy absorption capability especially during an earthquake and can absorb vibration energy very efficiently. For the purpose.
[0017]
The vibration damping structure of a PC frame according to claim 1 is formed by pressure bonding a column made of cast-in-place concrete or a precast column member and a beam made of a precast beam member by a PC pressure bonding method using prestress, Ri Na by installing a damper to absorb the vibration energy by utilizing the separation deformation of joint, prior Symbol crimped joint through a rigid member to expand the spacing deformation of the joint and the dowel muscle steel dampers, oil A damper or a steel rod damper is installed.
[0018]
In this case, the column and the beam are bonded by pressure bonding by the bond PC method, and the stress is transmitted at the bonded portion between the column and the beam by the pressure bonding force due to the prestress introduced through the PC steel material.
[0019]
As the PC steel material, for example, a PC steel strand or a PC steel rod may be used, and prestress may be introduced into the joint between the column and the beam by a post tension method.
The vibration damping structure of the PC frame constructed in this way behaves differently from the RC structure. When repeated loads such as seismic loads are applied to the building, the joint surface bends at the crimped joint between the column and the beam. Rotation causes separation deformation that separates from each other. Then, the separation deformation is expanded by the rigid member and transmitted to the damper, and the vibration energy at the time of earthquake is absorbed by the damper operating very efficiently by the separation deformation.
[0020]
The vibration damping structure of a PC frame according to claim 2 is formed by pressure bonding a column made of cast-in-place concrete or a precast column member and a beam made of a precast beam member by a PC pressure bonding method using prestress, Ri Na by utilizing spaced deformation of the joint established a damper for absorbing vibration energy, the previous Kibashira and beams to compression bonding with unbonded PC method, spaced deformation of the compression bonding portion when large listening is The unbonded section length is limited to a certain range so that it does not become excessive, and a steel damper, oil damper or steel rod damper is installed in the crimped joint through a rigid member that expands the deformation of the dowel bar and the joint. It is characterized by being formed.
[0021]
By increasing the protruding length of the rigid member, a sufficient amount of deformation can be imparted to the damper by increasing the amount of space deformation of the crimp joint. Further, the amount of deformation introduced into the damper can be freely controlled by changing the protruding length of the rigid member.
[0023]
Also in this case, as the PC steel material, for example, a PC stranded wire or a PC steel bar is used, and prestress is introduced into the joint portion by a post-tension method.
[0024]
Further, the PC steel material requires rust prevention treatment, and therefore, a grout method for inserting the grout material into the sheath after inserting the PC steel material into the sheath previously arranged in the column and the beam, and tensioning the PC steel material, It is preferable to adopt an unbonding method in which an unbonded steel material having a rust preventive grease and its cover around the PC steel material is inserted into the sheath in the same manner and is tensioned.
[0025]
In addition, there are cases where the beam joint and the entire length of the beam have an unbonded structure, and there are cases where the unbonded structure is limited to a certain section of the beam end area. In order to obtain a sufficient amount of deformation for the damper to work effectively, it is not necessary to be excessive due to the uniform elongation of the PC steel material. Only in the unbonded PC structure.
[0026]
The vibration damping structure of the PC frame constructed in this way behaves differently from the RC structure, and when repeated loads such as seismic loads are applied to the building, it is bent at the crimped joint between the column and the beam. Rotation causes separation deformation such that the joint surfaces are separated from each other. And the vibration energy at the time of an earthquake is absorbed because a damper act | operates by this separation deformation.
[0027]
In addition, by using the unbonding method for crimp bonding, a sufficient amount of deformation can be given to the damper, but the amount of deformation introduced to the damper can be controlled freely by changing the unbonded section range length. can do.
[0030]
Here, the viscoelastic damper has fluidity like a fluid, exhibits a force proportional to the deformation speed due to viscous resistance, and has an elastic property like a spring and exhibits a force proportional to deformation. Is a general term for polymer materials that exhibit dynamic behavior with
[0031]
The viscoelastic damper exhibits a spring-like behavior with little viscous resistance when the deformation speed is slow, and has a damper effect that generates a large reaction force due to increased viscous resistance when it is fast.
[0032]
Further, when a certain force is applied to the steel damper, the steel damper is plastically deformed while maintaining the stress at that time, but when the force is removed, a large residual deformation remains. In order to reverse this deformation, it is necessary to apply a force in the opposite direction, which can absorb vibration energy due to repeated loads such as seismic motion, and obtain an effect as a damper.
[0034]
The dowel member in this case includes, for example, a type in which the dowel member is disposed horizontally and obliquely at the pressure-bonding joint between the column and the beam, and a type in which the dowel member is disposed horizontally in the slab on the beam cross section. Further, as the dowel member, for example, dowel bars are arranged after the column and the beam are joined by pressure bonding, and are integrated with the column and the beam by mortar grout. By installing this dowel member, even if the unbonded PC steel material breaks, it is possible to prevent the beam from dropping and rotating.
[0035]
[Action]
When a repeated load such as an earthquake load is applied to a PCaPC frame building, if the beam surface and the column surface that cause separation deformation are connected via a damper, the vibration energy is absorbed by the damper. Absorption capacity increases.
[0036]
Thereby, the force which acts on a building becomes small and the displacement at the time of vibration of a building becomes small. Further, the damper member of the present invention is relatively small, and the installation location is also the lower surface portion of the beam end portion, or the upper surface portion and the side surface portion of the column, so it can be installed inside the interior finishing material such as the ceiling. .
[0037]
In addition, there is no problem in design even if they are exposed as a direct ceiling finish. Economical design is possible.
[0038]
Further, the amount of deformation introduced into the damper is based on the separation deformation of the joint between the beam and the column, which can be expanded in the case of bond PC, and unbond section length in the case of unbond PC. By adjusting, it is possible to control the amount of deformation of the damper introduced to optimize the damping.
[0039]
Furthermore, in the case of unbonded PC, the dowel member that penetrates the crimp joint can prevent the beam that supports the floor from dropping or rotating in the event of a rupture due to delayed fracture of the PC steel material. Can increase the sex.
[0040]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 of the Invention
FIGS. 1A to 1E show an example of a vibration damping structure of a PC frame according to the present invention. In the drawing, PCa beams are provided on both sides of a beam joint portion of a column 1 made of cast-in-place concrete or a PCa column member. A beam 2 made of a member uses a plurality of PC steel materials 3 and is bonded by a PC pressure bonding method using prestress.
[0041]
The PC steel material 3 in this case penetrates the beam joint portion of the column 1 horizontally and is continuously inserted in the axial direction of the beam 2 on both sides, and the PC steel material 3 is tensioned and fixed to fix the beam 2 and A predetermined amount of prestress is introduced into the joint surface between the column 1 and the beam 2.
[0042]
Further, a double T-shaped steel 4 as a rigid member protrudes from the side surface portion of the column 1 at the joint portion, and a T-shaped steel 5 as a rigid member protrudes from the lower surface portion of the beam 2, and the double T-shaped steel 4 web 4a, The web 5a of the T-section steel 5 is inserted between 4a. Furthermore, a fixed gap 6 is provided between the webs 4 a and 5 a, and a viscoelastic body 7 is attached to the gap 6 as a damper.
[0043]
The double T-shaped steel 4 is formed by projecting two webs 4a in parallel on one side of the flange 4b, and the T-shaped steel 5 is formed by projecting one web 5a on one side of the flange 5b. ing. Note that three or more webs 4a of the double T-shaped steel 4 may be provided, and two or more webs 5a of the T-shaped steel 5 may be provided so as to protrude therefrom.
[0044]
The double T-shaped steel 4 formed in this way is fixed to the side surface of the column 1 with the flange 4b, and the T-shaped steel 5 is fixed to the lower surface of the beam 2 with the fixing bolt 8, or the column 1 and the beam. It is attached, for example, by welding to an embedding plate (not shown) embedded in the concrete of No. 2.
[0045]
The double T-shaped steel 4 and the T-shaped steel 5 may be attached to the column 1 and the beam 2 in reverse. Further, in this case, the double T-section steel 4 and the T-section steel 5 may be attached to the lower side of the beam 2 as shown in the figure, or on the upper side of the beam 2 or on both the lower side and the upper side of the beam 2. It may be attached. Further, it may be attached to one end side or both end sides of the beam 2.
[0046]
In such a configuration, when the building is shaken, the crimping joint surface between the column 1 and the beam 2 is subjected to separation deformation, and this separation deformation is applied to the double T-shaped steel 4 and T attached to the column 1 and the beam 2, respectively. The vibration is transmitted to the viscoelastic body 7 through the shape steel 5 and the vibrational energy of the building is absorbed by the viscoelastic body 7 having a viscous resistance.
[0047]
Embodiment 2 of the Invention
FIGS. 2A to 2E show other examples of the vibration damping structure of the PC frame according to the present invention. In the figure, the side portion of the column 1 at the junction between the column 1 and the beam 2 having the above-described configuration is shown. A T-shaped bracket 9 and a T-shaped bracket 10 project from the lower surface of the beam 2 as rigid members, and a steel damper 11 is attached between the T-shaped brackets 9 and 10 as a damper.
[0048]
For example, as shown in FIG. 2 (d), the steel damper 11 is a rectangular plate-like steel plate provided with a honeycomb-like opening, and has one vertical rib 11 a formed so as to be constricted in the center. One is a damper that undergoes plastic deformation under horizontal force.
[0049]
Further, two steel dampers 11 formed in this way are overlapped, and the lower end side is connected to the connecting plate 12 projecting horizontally from the web 9a of the T-shaped bracket 9, and the upper end side is the web 10a of the T-shaped bracket 10. Are attached by bolting with a plurality of fixing bolts 13. At that time, the web 9 a side of the connecting plate 12 is connected to the web 9 a by one connecting bolt 14.
[0050]
Therefore, between the T-shaped brackets 9 and 10, four dampers composed of vertical ribs 11a constricted at the center are attached.
Further, the steel damper 11 is rotatable with respect to the column 1 by connecting the web 9 a side of the connecting plate 12 to the web 9 a of the bracket 9 by one connecting bolt 14.
[0051]
In addition, you may increase the installation number of the steel dampers 11 according to a design load. Further, the T-shaped brackets 9 or 10 are respectively provided on the side surface of the column 1 and the lower surface of the beam 2 in the same manner as the double T-shaped bracket 4 and the T-shaped steel 5 shown in FIG.
[0052]
FIG. 2 (e) shows another example of the steel damper 11. By providing a trapezoidal hole in the rectangular plate-shaped steel plate, the vertical rib 11a that is plastically deformed by external force is constricted at the lower end. It is formed as follows.
[0053]
In such a configuration, when the building is shaken, the crimping joint surface between the column 1 and the beam 2 undergoes separation deformation, and this separation deformation is attached to the joint between the column 1 and the beam 2 respectively. It is transmitted to the steel damper 11 through 9 and 10, and vibration energy is absorbed by the vertical rib 11a of the steel damper 11 being plastically deformed.
[0054]
Embodiment 3 of the Invention
FIGS. 3A to 3E show other examples of the vibration damping structure of the PC frame according to the present invention. In the drawing, the side portion of the column 1 and the beam 2 at the joint portion between the column 1 and the beam 2 are shown. A double T-shaped bracket 15 and a T-shaped bracket 15a are provided as rigid members on the lower surface portion, and an oil damper 16 is attached as a damper between the double T-shaped bracket 15 and the T-shaped bracket 15a.
[0055]
The oil damper 16 includes a cylindrical cylinder 16b in which a viscous body 16a is enclosed, a piston 16c that reciprocates within the cylinder 16b, and a piston rod 16d that protrudes from the piston 16c to one end side of the cylinder 16b. An orifice (small hole) through which the viscous body 16a passes is formed.
[0056]
In the oil damper 16 configured in this way, the cylinder 16b is integrated with the T-shaped bracket 15a on the beam 2 side, and the tip of the piston rod 16d is connected to the double T-shaped bracket 15 on the column 1 side with one connecting bolt 17 respectively. It is attached by connecting. Therefore, the oil damper 16 is rotatably attached to the column 1.
[0057]
In such a configuration, when a vibration occurs in the building, separation deformation occurs in the pressure-bonding interface between the column 1 and the beam 2, and this separation deformation is attached to the junction between the column 1 and the beam 2 respectively. It is transmitted to the oil damper 16 via the bracket 15 and the T-shaped bracket 15a, and is converted into relative movement between the cylinder 16b and the piston 16c in the cylinder 16b. At that time, the vibration energy is absorbed by the piston 16c in which the orifice (small hole) is formed receiving the fluid resistance of the viscous body 16a.
[0058]
Embodiment 4 of the Invention
4A to 4D show another example of the vibration damping structure of the PC frame according to the present invention. In the figure, the insert 18 is provided on the side surface of the column 1 at the junction between the column 1 and the beam 2. A T-shaped bracket 19 protrudes from the lower surface of the beam 2, and a steel rod damper 20 is attached between the insert 18 and the T-shaped bracket 19.
[0059]
The steel rod damper 20 is formed in a rod shape from extremely soft steel such as low yield point steel or extremely low yield point steel, and has a constricted portion 20a having a small diameter near the center and male threads at the ends of the column 1 side and the beam 2 side. Portions 20b and 20c are formed respectively.
[0060]
Further, the column 1 side of the steel rod damper 20 is connected to the side surface portion of the column 1 by screwing the male screw portion 20b to the insert 18, and the connecting nut 21 and the T-shape are screwed to the male screw portion 20c. It is connected to the lower surface portion of the beam 2 via a connecting fitting 22 attached to the bracket 19.
[0061]
In such a configuration, when the building is shaken, the crimping joint surface between the column 1 and the beam 2 undergoes separation deformation, and the separation deformation is inserted into the joint 18 between the column 1 and the beam 2. It is transmitted to the steel rod damper 20 via the T-shaped bracket 19 and the connecting fitting 22.
[0062]
As a result, in the steel rod damper 20, stress concentrates on the constricted portion 20a that is somewhat smaller near the center, and the vibration energy is absorbed by plastic deformation from the constricted portion 20a.
[0063]
In any of the above examples 1 to 4, the mounting level of the damper is determined so as to appropriately introduce the deformation from the lower end or upper end of the beam 2 to the damper, and the connection between the column 1 and the beam 2 is performed. In the case of unbonded PC crimping, as shown in FIGS. 1B and 1C and FIGS. 5A to 5C, a dowel bar 23 is crimped as a dowel member at a crimped joint between a column and a beam. The bar is penetrated through the joint and the unbond section length is appropriately adjusted.
[0064]
In the examples 1 to 4, reference numeral 24 denotes a joint member that fills the gap between the column 1 and the beam 2.
[0065]
【The invention's effect】
The present invention is as described above, and the vibration damping structure of the PC frame according to the present invention is a viscoelastic body, a steel plate, oil, a steel rod, etc., which is attached as a damper to a pressure-bonding junction between a column and a beam. Since the vibration energy is absorbed by utilizing the deformation of the slab, the energy absorption ability due to the deformation history of the PC frame can be remarkably increased, and the response shear force, response displacement, etc. during vibration can be reduced.
[0066]
Further, in particular, the amount of deformation introduced into the damper is based on the separation deformation of the joint between the beam and the column. In the case of bond PC, by adjusting the protruding length of the rigid member, In this case, by adjusting the unbond section length, it is possible to control the amount of deformation for introducing the damper for optimizing the damping.
[0067]
Also, the damper may be relatively small, so it can be installed inside interior finishing materials such as in the ceiling of a building, so there is almost no restriction on the placement location in the architectural plan, and the appearance after finishing It can be the same as a building without a damper.
[0068]
Economically, it is relatively inexpensive in terms of cost, and an optimal number can be distributed and arranged according to the required performance of the building, so that it is possible to design an economical frame.
Moreover, it is possible to form a crimping frame by any of the PC methods of bonding and unbonding.
[0069]
In particular, in the case of an unbonded PC, a dowel member penetrating the crimping joint is installed, so that the beam supporting the floor is prevented from dropping or rotating in the event of a failure due to delayed fracture of the PC steel material. Because it is possible, it is excellent in safety.
[Brief description of the drawings]
FIG. 1A is a schematic diagram of a PC frame configured to absorb vibration energy using separation deformation of a crimp joint, and FIG. 1B is an illustration of a column beam joint when a viscoelastic damper is used. (C) is a sectional view taken along the line II of (b), (d) is an enlarged view of the portion C of (c), and (e) is a sectional view taken along the line A of (d).
2A is an enlarged view of a beam-column joint when using a steel damper, FIG. 2B is a cross-sectional view taken along the line A in FIG. 2A, and FIG. (D), (e) is the elements on larger scale of (a).
3A is an enlarged view of a beam-column joint when using an oil damper, FIG. 3B is a cross-sectional view taken along the line of FIG. 3A, and FIG. 3C is an enlarged view of a portion of FIG. (d) is a cross-sectional view taken along the line of (c), and (e) is a partially broken side view showing the inside of the oil damper.
4A is an enlarged view of a beam-column joint when using a steel rod damper, FIG. 4B is a sectional view of the conductor line of FIG. 4A, and FIG. (D) is a soot line sectional view of (c).
5A is an elevation view when a dowel bar is installed in the beam cross section, FIG. 5B is a plan view of FIG. 5A, and FIG. 5C is a stand view when the dowel bar is installed in the slab section; FIG.
FIGS. 6A and 6B are schematic diagrams of a vibration damping structure using conventional separation deformation. FIGS.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Column 2 Beam 3 PC steel material 4 Double T-shaped steel 4a Web 4b Flange 5 T-shaped steel 5a Web 5b Flange 6 Gap 7 Viscoelastic body 8 Fixing bolt 9 T-shaped bracket 10 T-shaped bracket 11 Steel damper
11a Vertical rib 12 Connecting plate 13 Fixing bolt 14 Connecting bolt 15 Double T-shaped bracket
15a T bracket 16 Oil damper
16a viscous material
16b cylinder
16c piston
16d Piston rod 17 Connecting bolt 18 Insert 19 T bracket 20 Steel rod damper
20a Constriction
20b Male thread
20c Male threaded portion 21 Connecting nut 22 Connecting bracket 23 Dowel bar 24 Joint member

Claims (2)

A column made of cast-in-place concrete or a precast column member and a beam made of a precast beam member are crimped and joined by a PC crimping method using prestress, and vibration energy is applied to the crimped joint using the separation deformation of the joint. absorbing Ri name installed damper, before Symbol crimped joint through a rigid member to expand the spacing deformation of the joint and the dowel muscle steel damper, characterized by being installed oil damper or steel bar damper The vibration damping structure of the PC frame. A column made of cast-in-place concrete or a precast column member and a beam made of a precast beam member are crimped and joined by a PC crimping method using prestress, and vibration energy is applied to the crimped joint using the separation deformation of the joint. the absorbing damper Ri name installed, before the Kibashira and beams to compression bonding with unbonded PC method, spaced deformation of the compression bonding portion when large heard certain unbonded section length so as not it excessive range The vibration damping of a PC frame is characterized in that a steel damper, an oil damper, or a steel rod damper is installed in the crimped joint through a rigid member that enlarges the deformation of the joint between the dowel bar and the joint. Construction.

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