JP2011246937A - Building structure using post with wall provided with earthquake control prestress - Google Patents

Abstract

PROBLEM TO BE SOLVED: To significantly increase cross-section bending resistance by reasonably and effectively utilizing a cross-section performance considering a concrete post with walls as a unified cross-section and thereby preventing a building structure from being cracked and damaged by maintaining a PC steel material and a reinforcing bar within an elasticity range even if receiving a impulsive tensile force and a bending moment due to large earthquake and strong wind.SOLUTION: The concrete post with walls 1 is a member integrally constructed of a post portion 2 and a wall portions 3 provided on the both sides of the post portion and having a modified cross-section. The post with walls provided with earthquake control prestress is formed by disposing PC steel materials 8, 10 by insertion and applying a tension-introducing force on the PC steel materials to tension-fix it. Thereby, the building structure can be designed to be within an elasticity range in which it does not yield even when the maximum tensile force is applied to the PC steel material due to large earthquake and strong wind. Also, the respective maximum tensile forces applied to the PC steel materials disposed in the post portion and the wall portion are almost equal to each other. Integration between the wall portion and the post portion significantly increases cross-section bending resistance. As a result, the building structure can be prevented from being cracked and damaged.

Description

  The present invention is a building constructed using a walled column, and is an earthquake-resistant and vibration-damped structure constructed by applying a damping prestress to a walled column so that it can withstand a large earthquake or strong wind pressure Is related to the building.

  A concrete building generally has a structure in which a column and a wall are connected in an RC structure, and a plurality of techniques for reinforcing the existing column and wall to a seismic structure are known. For example, as a first conventional example, when a permanent and emergency earthquake-proof reinforcement is applied to an existing wall-mounted column in a building, the wall portion is sandwiched by at least two plates arranged opposite to each other. After temporarily fixing the plate with a plurality of fastening members penetrating with the wall portion, concrete or mortar is applied to the gap formed between the plate, the column portion, and the wall portion and hardened. This is a permanent and emergency seismic reinforcement method for a walled column that tightens a binding member and introduces prestress (Patent Document 1).

  According to such a method, not only the seismic performance of the existing wall column can be maintained at a high level permanently, but even if it is damaged by an earthquake or the like, emergency reinforcement is performed by a relatively simple procedure. It will be possible.

  In addition, as a second conventional example, a method of seismic reinforcement of a pillar that reinforces an existing RC pillar by adding a sleeve wall, and manufacturing a sand-removed steel plate unit whose periphery is surrounded by a steel plate in advance, The closed-type steel plate that is also used as a formwork at the upper and lower ends of the column, with anchors being installed in the middle part of the column and beams on the upper and lower floors, and the wall bars of the sleeve wall being arranged through the anchor After placing the units and disposing the formwork between these closed type steel plate units, the seismic resistance of the pillars constructing the sleeve wall by filling the closed type steel plate unit and the formwork with a curable material and curing it. This is a reinforcing method (Patent Document 2).

  And since the closed type steel plate unit, which is also used as a formwork, is integrated into the upper and lower ends of the sleeve wall to be added, the hardenable material is crushed by the closed type steel plate unit due to the compressive force acting during a large earthquake. Therefore, the yield strength and deformation performance can be greatly improved.

  Furthermore, as a third conventional example, a steel plate with a stud on one side is built along any one of the front and back surfaces of an existing column, and fixed to the existing column; A step of assembling the remaining formwork including the other formwork, a step of filling or placing concrete or resin, and a step of demolding the formwork excluding the steel plate after the curing / forming period This is a method of adding and reinforcing sleeve walls on both sides of an existing pillar (Patent Document 3).

  According to the above reinforcing method, the construction method can be simplified, the anchor construction can be minimized or minimized, and the generation of noise during the construction period can be suppressed as much as possible. In addition, the existing pillars can be reinforced while using the building.

JP 2003-227236 A Japanese Patent Laid-Open No. 10-61256 JP 2008-163646 A

  In the conventional example, each is made of reinforced concrete. For example, when a walled column in which sleeve walls are evenly arranged on both sides of the column is taken as one member example, the wall portion is a member from the column portion in the member cross section. Is away from the neutral axis (centroid position of the column). In the current analytical design method, the relationship between the bending moment and the curvature is obtained on the assumption that the flat surface is maintained. Therefore, the tensile stress caused by the bending moment increases as the distance from the neutral axis of the cross section increases. Subjected to a greater tensile (compression) stress than the rebar of the part. Then, the magnitude of the stress generated in the reinforcing bars arranged in the member is determined by the distance from the neutral axis, and when the bending moment due to the horizontal force such as earthquake or strong wind is received, the wall part will resist the bending. Then, the reinforcing bar yields and collapses, and then the column part resists. Further, the wall thickness is only about 1/4 of the column width, and the rigidity of the wall is small compared to the rigidity of the column, so that integration with the column cannot be ensured. Therefore, the conventional walled columns cannot obtain bending strength as an integrated cross section, so the column part is treated separately as a vertical element and the wall part is handled separately as a seismic horizontal element. Despite having it, it is not reasonably available.

  In addition, in the past examples of direct-type short-period large earthquakes, the main reinforcement preceded the failure of the main reinforcement particularly in the columns and wall structures of reinforced concrete, which caused many shear failures. The reason is that the reinforcing bars arranged in the cross-section of vertical members such as columns and walls exceed the yield point strength, the adhesion force with concrete cannot follow the tensile elongation of steel, and adhesion failure at the adhesion interface with concrete, It is estimated that the main cause is peeling. In particular, the short-term instantaneous tensile elongation is a failure that breaks the entire cross section of a concrete column into a lump, which actually causes horizontal crack damage to the thick wall of the reactor structure. I am letting. In addition, the reinforced concrete structure has no force to restore the deformation of the member and residual deformation remains after the earthquake, so the crack that occurred can not be closed and it progresses greatly and it has a bad influence on the structural frame Lifetime is greatly reduced.

  On the other hand, in the conventional PC structure, the cross-sectional yield strength of the structural member is obtained based on the yield load (Py) of the PC steel during a large earthquake. However, since the PC steel material does not have a clear yield point, the yield load is set to 0.2% permanent elongation. The yield point strength is the value obtained by dividing the cross-sectional area of the PC steel using the yield load. As shown in FIG. 7, it is shown by a straight line up to about 85% of the yield load, and thereafter enters a non-linear restoring force state. When entering this stage, there is a risk that cracks will occur in the concrete cross section, and it will not be possible to prevent the elastic reinforcement damage of the main bars and PC steel.

  Therefore, in the prior art, damage to RC pillars and walls due to a large earthquake will cause fatal damage that leads to the entire building, and vertical members such as PC pillars and walls are made of PC steel and reinforcing bars. Because it is used with the required cross-sectional strength based on the yield point strength, there is a possibility that PC steel and rebar will reach the yield point strength due to a large earthquake. There is a problem that damage is expected.

  For concrete walled columns according to the prior art, how to use the cross-sectional performance rationally and effectively as an integrated cross-section to greatly increase the cross-sectional bending strength, impact tensile force and bending due to large earthquakes and strong winds Even if a moment is received, there is a problem to be solved by preventing the cracking and breakage by maintaining the PC steel material and the reinforcing bar within the range of the linear restoring force.

  The present invention is a building constructed using concrete walled columns as a specific means for solving the problems of the above-described conventional example, and the walled columns are provided on both sides of the column. It is a member having an odd-shaped cross section composed of a single wall, and in the cross section of the member, a PC steel material is inserted through each of the pillar and the wall, and a tension introducing force is applied to the PC steel material to fix the tension. Thus, the present invention provides a building characterized in that a pillar with a wall to which seismic prestress is applied is formed.

In the present invention, the tension introducing force is a tension introducing force applied to the PC steel material arranged on the column up to 80% of the PC steel yield load, and a tension introducing force applied to the PC steel material arranged on the wall is the PC steel material. 40 to 70% of the yield load; in the cross section of the walled column, when the column width is d and the wall thickness is t, the wall thickness ratio to the column width is t / d = 0. 3 or more; the walled pillar is made of precast concrete; the walled pillar is used in a plurality of locations of the building, and is arranged in a direction different from the direction in which the directions of the walls coincide; Further, the building includes, as an additional requirement, an upper structure, a foundation structure, and a seismic isolation device provided between the upper structure and the foundation structure.
In the present invention, the above-described tension introducing force means a tensile force applied to the PC steel material at the completion of fixing in the fixing portion.

  The building according to the present invention has a strong wind by applying a pre-stress control by inserting a PC steel material into each of a column portion and a wall portion of a walled column to give a necessary tension introduction force and fixing the tension. Although the tensile force applied to the PC steel increases due to a large earthquake, it can be designed to fit within the elastic range that does not yield even with the maximum tensile force, and thus the PC steel disposed on the column and wall The maximum tensile force applied to the wall is almost the same, and the cross section bending strength can be remarkably increased by integrating the wall portion and the column portion, and it is possible to prevent the damage of the building. .

It is sectional drawing which showed schematically the walled pillar used in order to construct the high-rise building which concerns on embodiment of this invention. It is the side view of the principal part which showed the example of the spot cast-in-place structure of the building using the walled pillar which concerns on the embodiment. It is the side view of the principal part which showed the example of the precast concrete structure of the building using the walled pillar which concerns on the embodiment. It is the side view of the principal part which showed the example which added the seismic isolation apparatus with the precast concrete structure of the building using the walled pillar which concerns on the embodiment. It is explanatory drawing of the building which showed schematically the example which concerns on arrangement | positioning of a walled column in the building using the walled column which concerns on the embodiment. (A)-(D) figure is the high-rise building which concerns on the embodiment, and is explanatory drawing which showed the deformation | transformation condition by the horizontal force received by a strong wind or a big earthquake, and the restoring force by prestress. It is a graph which shows the restoring force characteristic curve of PC steel materials used in the same embodiment.

  The present invention will be described in detail based on the illustrated embodiment. In FIG. 1, a walled column 1 used for a building is a structure in which wall portions 3 are integrally formed on both side surfaces of a column portion 2, that is, one structural member, and the walled column 1 is precast concrete. It can be made of cast or cast concrete.

  As a matter of course, a reinforcing bar is disposed in the walled column 1. That is, the column main reinforcement 4 and the band reinforcement 5 are arranged inside the column portion 2, and the wall vertical stripe 6 and the band reinforcement 7 are arranged inside the wall portion 3. In this case, the band reinforcement In order to improve the bending strength as a cross section of one member by integrating the pillar and the wall, 7 is arranged as a continuous streak so as to penetrate the pillar portion 2 and connect to the wall portions 3 on both sides. It is. Further, a plurality of sheath tubes 9 for inserting the tensioning PC steel material 8 for applying the vibration control prestress inside the column portion 2 are disposed, and the same tension is applied to the inside of the wall portion 3. A plurality of sheath tubes 11 for inserting the PC steel material 10 are provided.

  The walled column 1 in which the column portion 2 and the wall portion 3 are integrally formed as described above is formed as a single structural member. In the case of cast-in-place concrete, the column formation D of the member and the overhang length of the wall are formed. Lw can be freely set according to the use of the building and the structural plan. In some cases, the wall 3 is also connected to each side surface (four sides) of the pillar 2 so as to be integrally formed. it can. Furthermore, in the case of a precast concrete structure, since there are restrictions on transportation, it is preferable that the total cross section Dw is 2.5 m or less. In any case, in the cross section of the walled column 1, when the width of the column part 2 is d and the thickness of the wall part 3 is t, the ratio of the wall thickness to the column width is t / d = 0. By setting it to 3 or more, integration of the column part 2 and the wall part 3 is ensured, and cross-sectional yield strength improves significantly.

  When constructing a high-rise building using the walled pillar 1 having the above-described configuration, for example, in the case of on-site concrete construction as the first embodiment, as shown in FIG. PC steel material 8 for tension and sheath tube 9 and PC for anchor material 13 for pillar 2 and anchor material 14 for wall 3 that are pre-embedded and attached to foundation concrete 12 in the foundation structure of the building, respectively. The steel material 10 and the sheath tube 11 are arranged in a connected state, and the column part 2, the wall part 3, the beam part 15, and the upper floor formwork (not shown) are assembled in the same manner as in a normal on-site punching process. After placing the reinforcing bars (4-7), the concrete is placed and compacted to be hardened. After the concrete on one floor is hardened, the pillars 2 of the upper floors are sequentially formed in the same manner as described above. Wall 3 and beam 15 and flow And of building a, PC steel 8,10 for tensioning is to be sequentially connected to that is disposed on the lower fixing.

  And the pillar 1 with a wall which gave the vibration suppression pre-stress is formed by giving tension | tensile_strength introduction force with respect to the PC steel materials 8 and 10 for tension | tensile_strength for every floor, and fixing tension | tensile_strength. In this case, the tension introduction force is up to 80% of the yield load of the PC steel material 8 for the PC steel material 8 inserted through the column portion 2, and for the PC steel material 10 inserted through the wall portion 3, The yield load is 40 to 70% of the PC steel material 10. In the case of this in-situ concrete construction, it is preferable to use a PC steel bar as the PC steel material.

  As a second embodiment, a case where a high-rise building is constructed using a precast concrete material is shown in FIG. In this embodiment as well, the same parts as those in the above embodiment will be described with the same reference numerals. In the PC structure walled column 1 to be used, sheath tubes 9 and 11 are disposed in advance in the column portion 2 and the wall portion 3, respectively. The foundation concrete 12 in the foundation structure of the building is provided with an anchor material 13 for the pillar portion 2 and an anchor material 14 for the wall portion 3 that are embedded and attached in advance.

  The anchors 13 and 14 are positioned so that the PC steel members 8 and 10 inserted into the walled column 1 can be connected to each other, and the walled column 1 of the PC structure is set. PC-structured beam members 15a and 15a are mounted on the upper surface from both sides, and sheath tubes 11a and 11a are respectively provided at positions corresponding to the sheath tube 11 provided on the wall 3 at the ends of the beam members 15a. After the beam members 15a and 15a are placed, the PC steel material 8 is inserted into the sheath tube 9 of the column portion 2, and the PC steel material 10 is inserted into the sheath tube 11 of the wall portion 2 and the corresponding 11a and 11a. The anchor members 13 and 14 are connected respectively.

  In this case, since the end portions of the mounted beam members 15a and 15a are not in contact with each other and a space corresponding to the column portion 2 is open, the sheath tube of the column portion 2 is located at the open interval position. After the sheath tube 9a corresponding to 9 is disposed, the space between the ends of the beam members 15a, 15a is filled with the cast-in-place concrete 16, and the top concrete 17 for the floor including the upper surfaces of the beam members 15a, 15a is also provided. After the placement and hardening of these cast-in-place concrete, the prestressing prestress is applied by applying a tension introducing force to the PC steel materials 8 and 10 and fixing the tension in the same manner as in the above embodiment. In addition, when the material of the PC structure in this embodiment is used, for example, a PC steel rod is used as the PC steel materials 8 and 10, and a PC having a length corresponding to a plurality of floors, for example, two to three floors instead of each floor. By using a steel bar and tension fixing force by 2-3 floors, that is, the PC crimping method or the PC crimping joint method, the walled column 1 to which the seismic prestress is applied as a whole is formed. May be.

  In this way, PC steel bars can be used as PC steel materials 8 and 10, and PC steel bars can be connected at each fixing part, and can be connected in series from the foundation concrete 12 to the top floor ceiling of the high-rise building. In addition, by applying seismic prestress over the entire length, the entire structure is stabilized, and a building member having a PC structure is used, so that the building can be efficiently constructed in a short period of time.

  Furthermore, as shown in FIG. 4, the high-rise building which is 3rd Embodiment can also be made into a seismic isolation structure using the above-mentioned pillar 1 with a wall. As an example, the case where a material having a PC structure is used will be described with the same reference numerals given to the same portions as those in the second embodiment. A lower substrate 21 is integrally attached to a concrete 19 placed on a pile head of a steel pipe pile 18 in a foundation structure as a building via an anchor material 20, and the periphery of the steel pipe pile 18 is formed as a foundation structure by a foundation slab 22. It has been hardened.

  In this embodiment, a base-isolated structure, that is, an upper structure is built on the foundation structure, and the PC-structured wall-mounted column 1 is attached to the lower concrete beam 23 which is the upper structure. Are attached via anchor members 13 and 14. In this case, the basic concrete 12 referred to in the second embodiment corresponds to the lower concrete large beam 23 of the upper structure, and the lower substrate provided at the pile head of the lower concrete large beam 23 and the steel pipe pile 18. The seismic isolation device 24 is arranged between the two. In this case, a projecting portion 23a having a required size is integrally provided on the lower surface of the lower concrete beam 23, and is exempted between the upper substrate 25 and the lower substrate 21 provided on the lower surface of the projecting portion 23a. A seismic device 24 is provided. In addition, when the lower concrete girder 23 is arrange | positioned by PC crimping or a PC crimping joint method via a footing member etc., the walled pillar 1 is also attached to the upper part of a footing member via a required anchor member. The seismic isolation device 24 is also attached to the lower surface of the footing member via the upper substrate 25.

  In conventional seismic isolation structures using seismic isolation devices, the seismic energy was absorbed by the horizontal relative displacement with respect to the horizontal movement caused by the ocean type earthquake, and the seismic energy was prevented from acting on the superstructure. It was not possible to suppress vertical movement caused by a direct earthquake. However, as described above, by using the wall-mounted column 1 and the seismic isolation device 24 in combination, and making the wall-mounted column 1 seismic prestressed, the seismic energy due to the horizontal seismic force can be reduced. In addition to absorption, damage to columns and walls due to vertical movement can be prevented or suppressed, and in particular, there is an effect of relaxing the stress level due to a shock wave in the vertical direction. In short, after the earthquake, the restoring force due to seismic prestressing returns the building to its original position, eliminating the need for conventional seismic damping dampers, significantly improving the seismic performance of the entire building, and reducing costs. It also contributes to reduction.

  FIG. 5 shows an example of the arrangement of the walled pillars 1 in the building using the walled pillars 1 according to the respective embodiments. The gist of the present invention is that in the walled column 1 as shown in the figure, in order to improve the structural rigidity and strength in two directions of the X and Y axes in the building plane and to improve the balance of earthquake resistance or vibration control The basic configuration is to alternately use the directions of the wall portions 3, but the wall portion 3 of the walled column 1 can also be used depending on the floor plan of the building and the ratio of the length between the X axis and the Y axis. The direction can be appropriately selected, and when the room layout is increased, it is naturally possible to use the pillar 1a having no wall portion. However, even if it is the pillar 1a without a wall part, the structure which arrange | positions the sheath pipe | tube 9 in the inside, inserts the PC steel material 8, and gives a damping control prestress is employ | adopted.

  In any of the above-described embodiments, the building is constructed using the walled pillar 1 from the foundation or lower structure part of the building to the uppermost ceiling, and the PC steel material 8 inserted into the pillar part 2 is used. For high-rise buildings that are 80% or less of the yield load and have been pre-stressed with a tension introduction force of about 40 to 70% of the yield load for the PC steel material 10 inserted through the wall 3 and are subjected to seismic prestressing. The damping effect of the restoring force due to the damping prestress will be described based on the conceptual diagram shown in FIG. (A) The figure shows an example in which a high-rise building 27 is given a seismic prestress P in addition to the weight W of the building, and the strong horizontal force Q that the building 27 receives due to an earthquake or a strong wind. This is an indication.

  (B) The figure shows the restoring force b due to the prestress with respect to the horizontal force a. As shown in (C), the horizontal force a exceeding the deformation force of the building is temporarily received by a large earthquake. Even if the deformation c is within the range indicated by the phantom line, the restoring force b due to the prestress P applied to the PC steel materials 8 and 10 resists the horizontal force a and the building 27 is not damaged, FIG. As shown in FIG. 5, when the horizontal force stops working, the building 27 returns to the original state by the restoring force b due to the prestress. In this way, the restoring force due to the prestressing prestress applied to the PC steel materials 8 and 10 becomes a force that resists when the building is deformed by an earthquake or the like, that is, a force that tries to return to the original, and damages the building. Without damaging it, it exerts strong seismic control.

  Thus, even if the high-rise building 27 is constructed using the walled pillar 1, the tension is fixed to the PC steel members 8 and 10 provided by being inserted through the pillar part 2 and the wall part 3 with a necessary tension introduction force. By applying the vibration control prestress, the building 27 is in a series of elastically integrated with the vibration control prestress P from the lower structure to the upper structure. The strong shaking that occurs in the upper part (the uppermost floor) even when subjected to vibration due to a large earthquake or horizontal force resists the restoring force due to prestress and suppresses the entire whipping phenomenon. The damping damper performance is exhibited against the tensile force generated by the impact tensile force or bending moment, and all the main bars and PC steel materials arranged inside are kept within the linear restoring force range without yielding.

  Although a high-rise building using the walled pillar 1 according to the present invention has been described with respect to a PC-structure building that can withstand large earthquakes and strong winds, the present invention is not limited to this. It can also be applied to the construction of high-rise or low-rise buildings such as high-rise apartments and office buildings.

1 Column with wall 1a Column (column without wall)
2 Columns 3 Walls 4 Main bars for columns 5 Bands (hoops)
6 Vertical bars for walls 7 Strips for walls 8, 10 PC steel (PC steel bars)
9, 9a, 11, 11a Sheath tube 12 Foundation concrete 13, 14 Anchor member 15 Beam 15a Beam material (precast)
16 In-situ concrete 17 Top concrete 18 Steel pipe pile 19 Concrete 20 Anchor material 21 Lower substrate 22 Foundation slab 23 Lower concrete beam 23a Protrusion 24 Seismic isolation device 25 Upper substrate 27 High-rise building

The present invention is a building constructed using concrete walled columns as a specific means for solving the problems of the above-described conventional example, and the walled columns are provided on both sides of the column. A member having an odd-shaped cross section composed of a single wall, and in the member cross section, a PC steel material connected from the lower floor to the upper floor is inserted into the pillar and the wall, respectively, and is disposed on the PC steel material. tension walled columns I imparted with descriptor restless be introduced force given the tense fixing is formed in a cross section of the wall with pillars, the thickness of the wall to the column width and b is taken as t, pillars The thickness ratio of the wall to the width is set to t / b = 0.3 or more, and the tension introducing force is set to 80% of the PC steel yield load, and the tension introducing force applied to the PC steel arranged on the column is The tension introduction force applied to the PC steel material placed on the PC steel material yield load There is provided a building, characterized in that 40% to 70% of that.

The present invention smell Te, front Symbol walled pillar, it is precast concrete structure; and the walled columns are used in a plurality of locations of buildings, they are arranged in a direction different from the direction corresponding to the direction of the wall , As an additional requirement.
In the present invention, the above-described tension introducing force means a tensile force applied to the PC steel material at the completion of fixing in the fixing portion.

The building according to the present invention has a wall thickness ratio with respect to the column width of t / b = 0.3 or more when the column width is b and the wall thickness is t in the cross section of the walled column. is secured integrally by the can significantly increase the cross-sectional flexural strength, also inserted through the PC steel material with a respectively connected to the column portion of the wall column with a wall portion from the lower floors to the upper floors, pillars The prestress is set so that the tension introducing force given to the arranged PC steel is up to 80% of the PC steel yield load, and the tension introducing force given to the PC steel arranged on the wall is 40 to 70% of the PC steel yield load. By applying and fixing the tension, the tensile force applied to the PC steel increases due to strong winds and large earthquakes, but it can be designed to fit within the elastic range where it does not yield even with the maximum tensile force. Placed on wall and wall Maximum tensile force applied to the PC steel material becomes substantially the same, an excellent effect that it is possible to prevent damage to the building.

Claims (6)

A building constructed using concrete walled columns,
The walled pillar is a member having an odd-shaped cross section composed of a pillar and walls provided on both sides thereof,
In the member cross section, the PC steel material is inserted through the column and the wall, respectively,
A building having a wall with a prestressing prestress formed by applying tension introduction force to the PC steel and fixing the tension. The tension introducing force is such that the tension introducing force applied to the PC steel arranged on the column is up to 80% of the PC steel yield load, and the tension introducing force applied to the PC steel arranged on the wall is 40% of the PC steel yield load. The building according to claim 1, characterized in that it is ˜70%. The wall thickness ratio with respect to the column width is t / b = 0.3 or more when the column width is b and the wall thickness is t in the cross section of the walled column. The building according to 1 or 2. The building according to any one of claims 1 to 3, wherein the walled column is made of precast concrete. 5. The building according to claim 1, wherein the walled pillar is used in a plurality of locations of the building, and is arranged in a direction different from a direction in which the directions of the walls coincide with each other. The building according to any one of claims 1 to 5, wherein the building includes an upper structure, a foundation structure, and a seismic isolation device provided between the upper structure and the foundation structure.

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