JP2000213062A - Aseismatic construction structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aseismatic structure having excellent aseismatic performance and capable of keeping a column axial force function even after yield by forming a column yield type hinge on an aseismatic intermediate column at the time of final proof stress of a skeleton while utilizing the features of a short span rigid frame structure in which the aseismatic intermediate column is erected on a beam. SOLUTION: A skeleton is constituted of a column 2, a beam 3, and an aseismatic intermediate column 4, the aseismatic intermediate column 4 is erected in a span intermediate part of the beam 3, the column 2 and the beam 3 are made of reinforced concrete, and the aseismatic intermediate column 4 is made of a steel frame. A width of a cross section of the aseismatic intermediate column 4 in a part where the beam 3 and the aseismatic intermediate column 4 are mutually joined is smaller than a width of a cross section of concrete of the beam 3, the aseismatic intermediate column 4 is erected over upper and lower stories by passing through the cross section of the concrete of the beam 3, and the beam 3 and the aseismatic intermediate column 4 form a rigid join part due to concrete bearing pressure strength of the beam 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an earthquake-resistant building structure applied to, for example, an apartment house.

[0002]

2. Description of the Related Art An earthquake-resistant building structure applied to an apartment house having a plurality of floors as described above is disclosed in, for example, Japanese Patent Publication No. 59-14.
As disclosed in Japanese Patent Publication No. 142 and Japanese Patent Publication No. 1-52549, a structure in which a ramen structure is arranged in a row direction is generally used.

FIG. 1 is an explanatory view corresponding to a front view showing an example of the above-mentioned earthquake-resistant building structure. In addition, the seismic building structure of FIG. 1 is 12 floors above the ground where the girder direction (longitudinal direction: left-right direction in FIG. 1) is 7 spans and the beam-to-beam direction (short direction: front-rear direction in FIG. 1) is 1 span. . Here, the “span” is a unit between two columns that are arranged to face each other, and one span is one unit, that is, a case where there are two columns.
Further, “span length” means a linear distance between columns, and “span number” means the number of spans.

In FIG. 1, 1 is a foundation, 2 is a column erected on the foundation 1, 3 is a beam, and 4 is an earthquake-resistant intermediate column erected on a beam 3 between the columns 2. Here, the beam 3 is a transverse member that connects the adjacent foundations 1 or columns 2 to each other in the horizontal direction for each floor, and includes a beam on the lowest floor (foundation beam) and a beam on two or more floors. . The ramen structure in the girder direction includes columns 2, beams 3, and earthquake-resistant intermediate columns 4. In the following, the pillar 2, the beam 3, and the quake-resistant intermediate pillar 4 are reinforced concrete
It may be described as "RC construction". ) Will be described.

The above-mentioned earthquake-resistant building structure has excellent seismic performance because the number of the columns 2 including the earthquake-resistant intermediate columns 4 is increased and the span length of the beams 3 is shortened by arranging the earthquake-resistant intermediate columns 4. It becomes a short span ramen structure. Here, pillar 2
Is erected on the foundation 1 so that the column axial force can be supported by the foundation 1. However, since the aseismic middle column 4 is erected in the middle of the span of the beam 3 (foundation beam or beam), the foundation 1 is not provided on the lowest floor of the aseismic middle column 4.

Accordingly, the transmission path of the vertical load of the floor or the like applied to the beam 3 of each floor to the foundation 1 includes a path for transmitting the vertical load to the columns 2 at both ends via the beam 3 of the floor, and a transmission path of the floor of the floor. Beam 3
There is a path that accumulatively transmits as the column axial force to the lower aseismic intermediate column 4 joined to the lower floor and is transmitted to the foundation 1 at both ends of the span by the lowest beam, ie, the foundation beam. The route transmitted from the beam to the foundation 1 is dominant.

[0007]

The conventional RC short-span rigid frame structure is excellent as a structure in the girder direction of a low-rise apartment house. However, high-rise apartment buildings on the 10th to 25th floors require not only the horizontal strength of the frame but also excellent deformation performance, and a high level of seismic performance that is stable from the elastic range of the frame to the ultimate strength. In particular, it is necessary to secure a transmission path of the vertical load of the floor or the like applied to the beam 3 of each floor to the foundation 1 from the elastic region of the framework to the time of ultimate strength. Therefore, a column-yield type mechanism that generates a yield hinge in the quake-resistant intermediate column 4 is important.

In the short-span rigid frame structure in which the seismic intermediate column 4 is made of RC, a column yielding mechanism for generating a yield hinge on the seismic intermediate column 4 is formed over the entire floor at the time of ultimate strength of the frame. Can be difficult to do.
In an apartment house, as shown in FIGS. 15 and 16, there is a request to make the concrete section width of the aseismic intermediate column 4 and the beam 3 the same. This is due to architectural planning and construction not to expose the pillars in the room. In addition, since the beam main reinforcement is inserted and arranged inside the column main reinforcement, even if the beam width is increased, the cover thickness of the beam main reinforcement becomes unnecessarily large.

Accordingly, the quake-resistant intermediate column 4 has a horizontally long rectangular cross-sectional shape, and the concrete cross-section width of the beam 3 is large, but there is a disadvantage that the cover thickness of the main reinforcement becomes excessive.
In addition, even if the beam concrete section becomes large, only the weight increases, and the number of main bars that can be arranged is also limited, resulting in a cost problem. As described above, the quake-resistant intermediate column 4 has a horizontally long rectangular cross section, and in order to prevent the design of shear failure, the yield strength of the cross section increases accordingly. Further, the formula for calculating the yield strength of the section of the RC quake-resistant intermediate column 4 is not a theoretical formula but an empirical formula, and it is also a matter to be considered in design that the calculated value and the actual strength value vary.

On the other hand, there is a restriction on making the sectional yield strength of the beam 3 larger than the sectional yield strength of the aseismic intermediate column 4. In a multi-family house, the same floor height is often used over all floors, and it is desirable that the beam structure (height of the beam 3) be the same on all floors.

Here, since the beam 3 is greatly affected by the long-term vertical load, it is necessary to examine the sectional yield strength against the long-term vertical load and the stress of seismic force. Further, the beam 3 must be sufficiently reinforced by shearing so as not to cause shear failure. However, as the effective span length between the column 2 and the aseismic intermediate column 4 is smaller, the design shear force for shear reinforcement is larger. This is one of the features of the short span rigid frame structure. In this regard, it is desirable that the width (composition) of the earthquake-resistant intermediate column 4 in the span direction is small.

Further, in the event that the yield strength hinge does not occur on the aseismic intermediate column 4 at the time of the ultimate strength of the frame and the yield strength hinge of the beam yield type is generated in the middle part of the beam 3 on each floor, FIG. 17 or FIG. As shown, a maximum of four hinges are formed at the joint end between the column 2 and the beam 3 at both ends and the joint end between the beam 3 and the quake-resistant intermediate column 4 in the span. In FIG. 17, M
g1 and Mg2 indicate beam bending moments, Mc1 and Mc2 indicate column bending moments, and Pn (n = 1 to 3) indicates horizontal force at each floor. Also, in FIG. 18, Nn (n = 1 to
4) shows the column axial force of each floor of the earthquake-resistant intermediate column.

The beam 3 on the floor where the beam yielding hinge is formed in the middle of the span as described above is a structural member that is ineffective against long-term vertical loads and seismic forces.
Therefore, as shown by the dotted line in FIG. 18, the long-term vertical load of the lower beam 3 capable of supporting the column axial force sharply increases. On the other hand, the column yielding type frame in which the yield hinge is formed on the column base and the column head of the aseismic intermediate column 4 is stable.

However, even in the case of the column yielding type of the earthquake-resistant intermediate column 4, in the case of concrete compression failure or shear failure,
The seismic column 4 may lose its axial force function. In addition, even if it is a beam yielding type of the middle part of the span or a column yielding type of the earthquake-resistant intermediate column, in the case of concrete compressive failure or shear failure, due to the specificity of the frame on which the earthquake-resistant intermediate column 4 is erected, It is necessary to configure the frame so that the transmission path of the vertical load such as the floor applied to the beam 3 to the foundation 1 is maintained from the elastic range of the frame to the time of ultimate strength.

The present invention provides a mixed structure in which a reinforced concrete frame from low to high is provided with a steel-framed quake-resistant intermediate column standing in the middle of the span, without impairing the economical efficiency. It is an object of the present invention to provide an earthquake-resistant building structure that is rich in structural characteristics such as horizontal rigidity or toughness and can greatly improve the flexibility of building design. In addition, while taking advantage of the characteristics of the short span rigid frame structure in which the seismic resistant intermediate columns are erected on the beams, at the time of ultimate strength of the frame,
An object of the present invention is to provide a seismic building structure having excellent seismic performance in which a column yielding type hinge is formed on an earthquake-resistant intermediate column and the column axial force function can be maintained even after yielding.

[0016]

An earthquake-resistant building structure according to the present invention is composed of a frame having columns, beams, and earthquake-resistant intermediate columns. And reinforced concrete columns and beams,
The quake-resistant intermediate column is made of steel (Claim 1). Then, the cross-sectional width of the quake-resistant intermediate column at the joint between the beam and the quake-resistant intermediate column is made smaller than the concrete cross-section width of the beam, and the quake-resistant intermediate column is erected on the upper and lower floors through the concrete section of the beam. (Claim 2), the beam and the quake-resistant intermediate column form a rigid joint by the concrete bearing strength of the beam (Claim 3), and further, the bearing-reinforcement member is attached to the beam from the quake-resistant intermediate column. It is projected into the concrete section (claim 4).

According to the first aspect of the present invention, at the time of ultimate strength of the frame, at the position near the joint between the beam and the seismic intermediate column,
By making the cross-sectional yield strength of the aseismic intermediate column smaller than the cross-sectional yield strength of the beam, a column yielding type yield hinge is formed (claim 5). By increasing the cross-section buckling strength,
The axial force generated in the quake-resistant intermediate column is transmitted to the lower beam (claim 6). Further, in the invention of claims 1 to 6, the quake-resistant intermediate column may be constituted by a very low yield point steel having a high toughness (claim 7). In the invention of claims 1 to 7, The steel members of the columns are covered with reinforced concrete members, and the reinforced concrete members that cover the reinforced concrete intermediate columns near the joints between the beams and the reinforced concrete intermediate columns so that the reinforced concrete members are not structurally integrated with the reinforced concrete members of the beams. A structural slit is provided in at least one of the column cap and the column base (claim 8).

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory view corresponding to a front view showing an earthquake-resistant building structure of the present invention. In FIG. 1, the earthquake-resistant building structure is composed of a skeleton including columns 2, beams 3, and earthquake-resistant intermediate columns 4 as described above. The column 2 is erected on the foundation 1, and the earthquake-resistant intermediate column 4 is erected on the middle of the span of the beam 3 (foundation beam or ordinary beam). Also, in the earthquake-resistant building structure, columns 2 and beams 3 are made of reinforced concrete (RC
), And the earthquake-resistant intermediate column 4 is a steel structure.

The frame means a frame in which wire members such as columns 2, beams 3, and quake-resistant intermediate columns 4 are combined with surface members such as quake-resistant walls, wall braces, and damping walls. And although the ramen structure in which the pillar 2 and the beam 3 are arranged in a lattice shape is common,
The ramen structure is not limited to this, and may be a frame having an arbitrary front shape, a frame partially including a truss structure, or the like. Further, the beam 3 is a horizontal member connecting the adjacent foundations 1 or the columns 2 to each other in a horizontal direction for each floor, and includes a beam on the lowest floor (foundation beam), a beam on two or more general floors, and a beam on the upper and lower floors. It includes a surface member such as an earthquake-resistant wall integrated between beams, and is a structural member effective for a vertical load such as a floor and a horizontal force such as a seismic force.

FIG. 2 is an explanatory view corresponding to a front view showing a beam, an earthquake-resistant intermediate column and a bearing member in the first embodiment of the present invention. FIG. 3 is a beam and an earthquake-resistant intermediate column in the first embodiment of the present invention. FIG. 4 is an explanatory view corresponding to a plan view showing a bearing reinforcing member, FIG. 4 is an explanatory view corresponding to a side view showing a beam, an earthquake-resistant intermediate column and a bearing reinforcing member in the first embodiment of the present invention, and FIG. Explanatory view corresponding to a front view showing an intermediate column joint, which is a joint between a beam and an earthquake-resistant intermediate column in the first embodiment of the present invention, and FIG. 6 is a plan view showing an intermediate joint in the first embodiment of the present invention. FIG. Note that, in FIG. 2, the reinforcing bars (main bars, shear reinforcing bars) of the columns are omitted.

In these figures, reference numeral 5 denotes a bearing reinforcing member erected on the earthquake-resistant intermediate column 4 and projects into the concrete section of the beam 3. Reference numeral 6 denotes a horizontal reinforcing plate. Mg1,
Mg2 is the beam bending moment, Mc1 and Mc2 are the column bending moment, Qv is the vertical shear force, Qh is the horizontal shear force,
Dc indicates the seismic middle column, Dg indicates the beam, Bc indicates the cross-sectional width of the middle column, and Bg indicates the concrete cross-sectional width of the beam 3.

Next, the configuration of the earthquake-resistant intermediate column 4 will be described. As shown in FIGS. 2 to 6, the section width Bc of the aseismic intermediate column 4 at the joint between the beam 3 and the aseismic intermediate column 4 (hereinafter referred to as “intermediate column joint”) is the concrete section width of the beam 3. B
Since it is smaller than g, on the intermediate floor, the earthquake-resistant intermediate column 4 penetrates through the concrete section of the beam 3 and stands on the beam 3 over the upper and lower floors. An H-section steel is used as the earthquake-resistant intermediate column 4, and the strong axis direction of the cross section of the H-section steel is oriented in the direction of the material axis of the beam 3.

Incidentally, general steel materials such as SN400B and SN490B can be used as the steel material type of the H-shaped steel, and the toughness of the structure can be enhanced by utilizing the deformation performance of the H-shaped steel. Although not shown in the drawings, the joining of the steel members of the aseismic intermediate column 4 at the site is performed by high-strength friction bolt joining, welding, or the like.

Next, the function of the intermediate column 4 will be described. As shown in each drawing, the number of columns can be increased and the span length of the beam 3 can be shortened by arranging the quake-resistant intermediate columns 4, so that a short-span rigid frame structure excellent in quake resistance can be configured. Therefore, the earthquake-resistant intermediate column 4 has a function of increasing the horizontal rigidity and the horizontal strength of the earthquake-resistant building structure. Furthermore, since the steel-framed earthquake-resistant intermediate column 4 is rich in toughness, it functions as a vibration-damping member that retains deformation performance even if the end yields during an earthquake and can absorb energy.

Further, since the aseismic intermediate column 4 is erected in the middle of the span of the beam 3, it has a column axial force function for directly supporting the beam 3 of each floor, and also has a function such as a floor added to the beam 3 of each floor. Seismic intermediate column 4 on the lower floor that joins the vertical load to the beam 3 on the floor
Also has a column axial force transmitting function of transmitting the column axial force cumulatively to the base 1 at both ends of the span by the lowest beam 3 (foundation beam). However, since the foundation 1 is not provided on the lowest floor of the seismic intermediate column 4, the axial force generated on the seismic intermediate column 4 of each floor due to the vertical load is caused by the column 2 standing on the foundation 1 at both ends of the span. Is smaller than the column axial force generated at the time. That is, regarding the column axial force, the earthquake-resistant intermediate column 4 has intermediate properties between the column 2 and the beam 3.

Next, the structure of the intermediate column joint will be described. As shown in FIG. 5 and FIG. 6, two pairs of horizontal reinforcing plates 6 are paired with the H-shaped steel of the quake-resistant intermediate column 4 in the upper and lower pairs near the upper and lower ends of the concrete section of the beam 3. Are fixed so as to be integrated into an intermediate joint. Then, a shear panel portion (joint portion) reinforced by the horizontal reinforcing plate 6 and the H-section steel flange is formed.

Further, the bearing reinforcing member 5 uses an H-shaped steel,
It is fixed to the flange of the earthquake-resistant intermediate column 4 by welding. The bearing reinforcing member 5 is a projection that is three-dimensionally fixed to the flange surface of the earthquake-resistant intermediate column and protrudes into the beam concrete. Then, the shear strength between the bearing reinforcing member 5 and the beam concrete resists the vertical shear force generated at the intermediate column joint portion.

The height in the vertical direction and the length in the horizontal direction of the H-section steel of the bearing reinforcing member 5 are determined by the bending moments Mg1, Mg2, M
It is calculated by c1 and Mc2. The horizontal length of the bearing reinforcing member 5 is usually about 50 mm to 150 mm, but is not limited thereto. Therefore, according to the present invention, the protruding length of the bearing reinforcing member 5 provided on the earthquake-resistant intermediate column 4 becomes extremely small, or if the bearing reinforcing member 5 does not need to be provided, it protrudes from the earthquake-resistant intermediate column 4. There is an advantage that members are eliminated.

At the joint of the intermediate column, the main reinforcement of the beam 3 is arranged so as to avoid the H-shaped steel flange of the intermediate column 4, and the shear reinforcement (stirrup) is also provided at the H of the intermediate column 4.
Through-holes are provided in the web of the section steel to integrate the shear reinforcing bars on the right and left cross sections. Further, the beam 3 has a concrete cross section and a reinforcing bar arrangement which are not interrupted by the aseismic intermediate column 4 over the entire span. This is because the seismic intermediate column 4 is treated as an auxiliary structural member, and the structural performance of the beam 3 is given priority.

Next, the rigid joint will be described. As shown in FIG. 5, the left and right beam bending moments M of the intermediate column joint are shown.
By g1 and Mg2, the compressive force generated between the upper and lower ends of the beam 3 and the H-shaped steel of the aseismic intermediate column 4 is resisted by the concrete bearing strength. For this reason, the RC beam 3 and the aseismic intermediate column 4 penetrating the beam 3 form a rigid joint.

Here, the concrete bearing strength is a value obtained by dividing the maximum compressible load that can be sustained when the concrete is locally subjected to a compressive load by the load acting area. It can withstand larger compressive stress than the case. And the concrete bearing strength Fn is

[0032]

(Equation 1)

However, Fc: normal compressive strength Ac: bearing area of concrete where stress is distributed uniformly away from the bearing end A1: bearing area under local compression

The rigid joint is such that the mutual angle between the joined beam 3 and the quake-resistant intermediate column 4 (the angle between the tangents at the nodes of each member after deformation) does not change even when an external force is applied. The joint of the ramen structure is a rigid joint. However, in the present invention, in addition to the complete rigid joint having the same angle, the rigid joint includes, for example, an imperfect rigid joint in which the component of the intermediate column joint yields and the angle changes. .

When the rigid joint is formed in this manner, a shear force is generated at the joint of the intermediate column, but the shear strength of the web of the H-section steel of the intermediate column 4 and the flange of the H-section steel of the intermediate column 4 are different from each other. It resists by three factors of the shear strength of concrete surrounded by a pair of upper and lower horizontal reinforcing plates 6, and the shear strength between the bearing reinforcing member 5 and the concrete. In addition, when the shearing force of the intermediate column joint is sufficient, the bearing reinforcing member 5 can be omitted.

Next, a description will be given of the intermediate pillar joint on the top floor or the bottom floor. First, on the lowest floor, although not shown, the aseismic intermediate column 4 is embedded in the concrete section of the lowest floor beam 3 (foundation beam) or the lowest floor beam 3 (foundation beam). A steel base plate may be placed on the upper end of the beam and anchor bolts may be fixed in the concrete of the beam 3 (foundation beam). Next, on the top floor, although not shown, the earthquake-resistant intermediate column 4 is embedded in the concrete section of the beam 3.

FIG. 7 is an explanatory view showing a case where a beam yielding type yield hinge is generated on a beam on each floor and a column yielding type hinge is generated on an earthquake-resistant intermediate column on each floor when the frame is ultimately subjected to a proof stress according to the present invention. Detailed description of the bending moment by the horizontal force when the yield strength of the beam yielding type occurs in the beam of each floor at the ultimate strength of the frame in the present invention, and the yielding hinge of the column yield type occurs in the seismic intermediate column of each floor, FIG. 9 shows a case in which a beam yielding type yield hinge is generated on a beam on each floor at the time of ultimate strength of a frame according to the present invention, and a column yielding type hinge is generated on a seismic intermediate column on each floor. FIG. 3 is a detailed explanatory view of a bending moment and a column axis of an earthquake-resistant intermediate column.

In these figures, Pn (n = 1 to 1)
2) is horizontal force at each floor, Mg1 and Mg2 are beam bending moments, Mc1 and Mc2 are column bending moments, Nn
(N = 1 to 4) indicates a column axial force.

Next, the form (mechanism) of collapse of the frame will be described. As a means to evaluate the seismic performance of an earthquake-resistant building structure, there is a collapse form at the time of ultimate strength of the frame. For general ramen structures, a beam yield type on the middle floor and a column yield type on the lowest floor are considered desirable. I have. Therefore, in the earthquake-resistant building structure, the joint between the column 2 and the beam 3 at both ends of the span is designed to be a beam yielding type on the middle floor and a column yielding type on the lowest floor.

However, from the feature that the aseismic middle column 4 is erected at the middle of the span of the beam 3, it is preferable that the buckling type of the aseismic middle column 4 be used not only at the lowest floor but also at the middle floor at the middle column joint. . Here, the ultimate strength of the frame is the maximum horizontal strength at which the frame collapses when it receives more horizontal force, and is also referred to as possessed horizontal strength.

At the time of ultimate strength of the frame, a column yield yield hinge is designed at a position near the intermediate column joint so that the sectional yield strength of the aseismic intermediate column 4 is smaller than the sectional yield strength of the beam 3. To form In this case, the quake-resistant intermediate column 4 is a virtual double-ended pin member that has a yield hinge at a column head and a column base on each floor, and maintains a constant yield bending moment after yielding, and functions as a vibration damping member. Therefore, since the beam yield hinge is not formed in the middle of the span of the beam 3, the entire frame has a stable structure from the elastic region to the ultimate strength.

The final form of collapse of the frame is that a column yielding hinge (black circles in FIGS. 7 to 9) is formed on the column head and column base of the aseismic intermediate column 4 on each floor, and a column is formed at both ends of the span on each floor. 2
Yield hinges (white circles in FIGS. 7 to 9) are formed at the joint between the beam and the beam 3, and the beam 3 becomes stable. FIG.
Shows the collapse type at the time of ultimate strength of the frame in which a column yielding type hinge yields on the seismic intermediate column 4 on the middle floor of each floor. In this case, the vertical load through the seismic intermediate column 4 is It is not transmitted to the beam 3 suddenly.

However, the present invention is not limited to this, and a beam yielding hinge may be formed in the middle of the span of the beam 3 on some floors. In this case, the beam yielding hinge may be used. It is necessary that the seismic middle column 4 on the lower floor, which is joined to the beam 3 having the ridges, has at least the column axial force function. For this purpose, by increasing the cross-sectional buckling strength of the quake-resistant intermediate column 4 to be greater than that of the quake-resistant intermediate column 4, the axial force generated in the quake-resistant intermediate column 4 is reduced to a lower beam. 3 is formed.

As described above, at the joint of the intermediate columns, not only the lowermost floor but also the intermediate floor is of the column yielding type of the earthquake-resistant intermediate column 4, and the beam yielding hinge is formed at the middle of the span of the beam 3 on each floor. Therefore, the load flowing to the lower floor as the column axial force on the earthquake-resistant intermediate column 4 does not suddenly increase the long-term vertical load of the beam 3 on the floor. That is, the path transmitted to each pillar 2 at both ends via the beam 3 of the floor for each floor, and cumulatively transmitted as the column axial force to the seismic intermediate column 4 on the lower floor joined to the beam 3 of the floor, The beam 3 on each floor, which is the path transmitted to the foundation 1 at both ends of the span by the beam 3 (foundation beam) on the lowest floor
The transmission path of the vertical load of the floor or the like applied to the foundation to the foundation 1 is stably secured from the elastic range of the framework to the time of ultimate strength.

Further, since the quake-resistant intermediate column 4 is a steel frame member, it allows bending yield, but it is easy to prevent compression buckling and shear failure. No loss of function. Further, since the sectional width of the aseismic intermediate column 4 is made smaller than the concrete sectional width of the beam 3 at the joint of the intermediate column, the sectional yield strength of the aseismic intermediate column 4 is reduced by the sectional yield strength of the concrete beam 3. It is easy to make smaller. And since the aseismic middle column 4 is a steel frame structure, the sectional yield strength can be calculated more accurately than the RC structure.

Further, since the quake-resistant intermediate column 4 has high toughness, its deformability is much better than the rigid frame structure composed of RC columns and beams. Therefore, even if the RC frame structure yields, the steel-made aseismic intermediate column 4 exhibits excellent deformation following ability. In addition, the cross-sectional width of the aseismic intermediate column 4 is made smaller than the concrete cross-sectional width of the beam 3, and the quake-resistant intermediate column 4 penetrates through the concrete cross section of the beam 3 and stands upright on the intermediate floor. The beam 3 has a concrete section and reinforcing bars that are not interrupted by the aseismic intermediate column 4 over the entire span, and the beam width is necessary to arrange the main reinforcing bars of the aseismic intermediate column 4 avoiding the steel members. The width may be sufficient, and the cover thickness of the beam main reinforcement is appropriately maintained.

Since the beam 3 and the aseismic intermediate column 4 form a rigid joint with the concrete bearing strength of the beam 3 at the intermediate column joint, the bearing reinforcing member 5 provided on the aseismic intermediate column 4
There is an advantage that the projecting length from the quake-resistant intermediate column 4 is eliminated if the projecting length becomes extremely small or if the bearing reinforcing member 5 does not need to be provided. In addition, since the structure of the intermediate column joint is simplified, the workability of concrete casting is improved.
Integration of the C-beam as a structural member that is not interrupted by the seismic intermediate column 4 over the entire span, design flexibility, cost reduction, etc., in which the steel member of the seismic intermediate column 4 is not an assembly material but a single material. There are advantages. Since the width of the aseismic intermediate column 4 in the span direction is small, the effective inner span length between the column 2 and the aseismic intermediate column 4 is reduced, and shear reinforcement of the RC beam 3 is facilitated.

FIG. 10 is an explanatory view corresponding to a front view showing an intermediate column joint of a seismic building structure according to a second embodiment of the present invention, and FIG. 11 is a seismic building structure according to the second embodiment of the present invention. It is explanatory drawing equivalent to the top view which shows the intermediate | middle pillar joint part. In the second embodiment, the aseismic intermediate column 4 is made of H-shaped steel, the bearing reinforcing member 5 is made of angle steel, and one set of horizontal reinforcing plates 6 is made of three pieces. A shear panel reinforcing plate 7 is attached to both sides of the web.

With this configuration, the same effect as in the first embodiment can be obtained.

Next, an earthquake-resistant building structure according to a third embodiment of the present invention will be described. In the third embodiment of the present invention, an earthquake-resistant intermediate column is formed of a very low yield point steel having a high toughness. As described above, when the earthquake-resistant intermediate column is made of a steel frame made of a tough steel material, it is preferable to use an extremely low yield point steel having excellent toughness performance. This is because, while the elongation performance of a general steel is 20% at break, the elongation of a tough steel is 40% or more at break, and the yield point strength of the tough steel is higher than that of general steel. This is because it shows a small value.

That is, the tough steel material yields with a low strength, but exhibits high toughness until the fracture after the yield. When an H-section steel is used for the earthquake-resistant intermediate column, one of the flange and the web may be a tough steel material, and the other may be a general steel material. Further, the toughness steel material is not limited to the H-section steel, and may be a member cross section of another shape.

FIG. 12 is an explanatory view corresponding to a front view showing a main part of an earthquake-resistant building structure according to a fourth embodiment of the present invention, and FIG. 13 is a view illustrating a main part of the earthquake-resistant building structure according to the fourth embodiment of the present invention. It is explanatory drawing corresponding to the top view which shows a part. 12 or 13, reference numeral 8 denotes a reinforced concrete member covering the steel frame member of the earthquake-resistant intermediate column 4, 9 denotes a predetermined width and a predetermined depth on at least one (preferably both) of the column head and the column base of the reinforced concrete member 8. FIG.

When the structural slit 9 is provided in this way, the main reinforcement of the reinforced concrete member 8 of the aseismic intermediate column 4 stops immediately before the structural slit 9 and passes through the structural slit 9 to make the beam 3.
The reinforced concrete member 8 of the aseismic intermediate column 4 is not structurally integrated with the reinforced concrete member of the beam 3, and the aseismic intermediate column 4 can function as a steel frame member.

Further, by simultaneously casting the concrete of the beam 3 and the quake-resistant intermediate column 4 on site, it is possible to omit the fire-resistant coating of the steel members of the quake-resistant intermediate column 4 and the dry finishing work. Instead of covering the steel member of the earthquake-resistant intermediate column 4 with the reinforced concrete member 8, the steel member may be covered as a dry finish such as a precast concrete plate or an ALC plate.

FIG. 14 is an explanatory view corresponding to a front view showing an earthquake-resistant building structure according to a fifth embodiment of the present invention. In FIG. 14, reference numeral 10 denotes an earthquake-resistant wall incorporated inside the ramen structure, and reference numeral 11 denotes a brace incorporated inside the ramen structure.

As shown in FIG. 14, the earthquake-resistant intermediate column 4 does not necessarily have to be erected from the lowest beam 3 (foundation beam), but extends from an arbitrary intermediate floor beam 3 to an arbitrary number of floors. May be installed, and furthermore, it may be erected in the span direction.
Flexibility in the floor plan of the building can be secured. Further, the earthquake-resistant wall 10 or the brace 11 can be incorporated into the ramen structure.

In each of the above embodiments, the present invention has been described as an example in which the present invention is applied to the girder direction of an apartment house. However, the present invention is not limited to this, and can be applied to other than the girder direction of an apartment house. . In addition, the flat form of the reference floor of the apartment house is not limited to the one-way corridor method or the middle-corridor method, but may be a hollow core method, a goose method, or the like. Further, the use of the building is not limited to the multi-family housing, and it can be widely applied to structures of buildings for other uses such as offices and hotels, and can be applied to a wide range of buildings from low-rise to high-rise. it can.

Although the example in which the foundation structure is a pile foundation has been described, the invention is not limited to this, and a direct foundation may be used. In addition, the RC structure may be cast in place of concrete or may be a precast concrete member. Further, the cross-sectional shape of the steel frame member of the earthquake-resistant intermediate column 4 may be a single member such as a steel pipe, a box-shaped steel pipe, or a cross-shaped assembly, or another shape, in addition to the H-section steel. And beam 3
In general, the lowermost floor, that is, the foundation beam is made of reinforced concrete, but is not limited to this, and may be, for example, steel-framed reinforced concrete, steel-framed, or prestressed reinforced concrete.

The quake-resistant intermediate column 4 is attached to the beam 3 having one span.
Although the example in which this is erected is described, a plurality of earthquake-resistant intermediate columns 4 may be erected on the beam 3 of one span. And, in the case of the intermediate column joint part due to the adhesive strength between the concrete of the beam 3 and the H-shaped steel of the beam steel frame bracket, the length of the beam steel frame bracket integrated with the earthquake-resistant intermediate column 4 is about 1000 mm. This is generally larger than the protruding length of the bearing reinforcing member at the rigid joint due to the bearing strength of concrete. Therefore, in the short-span rigid frame structure in which the span length of the beam 3 is short, the length of the bracket of the beam steel frame occupying the span length of the beam 3 is increased. When the length of the beam steel frame bracket is increased as shown in FIG.
As shown in (1), it is suitable when the earthquake-resistant intermediate pillar 4 is erected from a beam 3 on an arbitrary intermediate floor.

[0060]

As described above, according to the present invention, a mixed structure in which a steel-framed quake-resistant intermediate column is erected in the middle of a span on a reinforced concrete frame from a low-rise to a high-rise is provided. It is possible to provide an earthquake-resistant building structure that is rich in structural characteristics such as horizontal strength, horizontal rigidity, and toughness, and can greatly improve the flexibility of architectural design, without impairing flexibility. In addition, while utilizing the features of the short span rigid frame structure in which the seismic middle columns are erected on the beams, a column yielding hinge is formed on the seismic middle columns at the time of ultimate strength of the frame, and the column axial force function is maintained even after yielding. An earthquake-resistant building structure having excellent seismic performance that can be held can be provided.

According to the first aspect of the present invention, the columns and beams are made of reinforced concrete and the aseismic intermediate columns are made of steel. Therefore, the aseismic intermediate columns allow bending and yielding, but suffer from compression buckling and shear failure. It is easy to prevent, and the column axial force function is not lost even if the column yield hinge is formed. In addition, since the quake-resistant intermediate column has high toughness, its deformability is much better than that of a rigid frame structure composed of RC columns and beams. Therefore, even if the RC frame structure yields, the steel-made aseismic intermediate column exhibits excellent deformation follow-up ability.

According to the second aspect of the present invention, the sectional width of the quake-resistant intermediate column at the joint between the beam and the quake-resistant intermediate column is made smaller than the concrete sectional width of the beam, and the quake-resistant intermediate column is moved in the concrete section of the beam. Since it penetrated and was erected over the upper and lower floors, it is easy to make the cross-sectional yield strength of the aseismic intermediate column smaller than that of the concrete beam. In addition, the beam has a concrete section and reinforcing bars that are not interrupted by the aseismic intermediate column over the entire span, and the beam width is the width necessary to arrange the main reinforcing bars of the aseismic intermediate column avoiding the steel members. It is sufficient that the cover thickness of the main beam is properly maintained.

According to the third aspect of the present invention, since the beam and the quake-resistant intermediate column form a rigid joint according to the concrete bearing strength of the beam, the structure of the intermediate column joint can be simplified, and the beam concrete can be simplified. Improves the workability of casting, integration of RC beams as structural members that are not interrupted by seismic intermediate columns over the entire span, design flexibility to make the steel members of seismic intermediate columns a single material instead of assembling material There are advantages such as cost reduction. Since the width of the aseismic intermediate column in the span direction is small, the effective inner span length between the column and the aseismic intermediate column is reduced, and shear reinforcement of the RC beam is facilitated. According to the invention of claim 4, since the bearing member is projected from the seismic intermediate column into the concrete section of the beam, the shear force generated at the joint of the intermediate column is reduced by the shear force between the bearing member and concrete. Strength can be resisted, and the strength of the rigid joint between the beam and the quake-resistant intermediate column can be improved.

According to the fifth aspect of the present invention, at the time of ultimate strength of the frame, the sectional yield strength of the seismic intermediate column is made smaller than the sectional yield strength of the beam at a position near the joint between the beam and the seismic intermediate column. As a result, a yielding hinge of a column yielding type is formed, so that the quake-resistant intermediate column becomes a virtual double-ended pin member holding a constant yielding bending moment after yielding, and functions as a vibration damping member. Therefore, since the beam does not have a beam yielding hinge at the middle of the span, the entire frame has a stable structure from the elastic range to the ultimate strength. According to the invention of claim 6, by increasing the sectional compressive buckling strength of the aseismic intermediate column than the axial force generated in the aseismic intermediate column, the axial force generated in the aseismic intermediate column is applied to the lower floor beam. Since the transmission is performed, the seismic intermediate column can maintain the column axial force function.

According to the seventh aspect of the present invention, since the quake-resistant intermediate column is made of a very low yield point steel having a high toughness, the tough steel material yields with a low strength, but exhibits a high toughness performance until the fracture after the yield. I do. According to the invention of claim 8, the steel frame member of the earthquake-resistant intermediate column is covered with the reinforced concrete member, and the vicinity of the joint between the beam and the earthquake-resistant intermediate column so that this reinforced concrete member is not structurally integrated with the reinforced concrete member of the beam. By providing a structural slit in at least one of the column head and column base of the reinforced concrete member covering the aseismic intermediate column, the main reinforcement of the reinforced concrete member of the aseismic intermediate column stops immediately before the structural slit and passes through the structural slit As a result, the reinforced concrete member of the aseismic intermediate column is not structurally integrated with the reinforced concrete member of the beam, so that the aseismic intermediate column can function as a steel frame member. In addition, by simultaneously casting the concrete of the beam and the quake-resistant intermediate column at the site, it is possible to omit the fire-resistant coating of the steel members of the quake-resistant intermediate column and dry-type finishing work.

[Brief description of the drawings]

FIG. 1 is an explanatory view corresponding to a front view showing an earthquake-resistant building structure of the present invention.

FIG. 2 is an explanatory view corresponding to a front view showing a beam, an earthquake-resistant intermediate column, and a bearing reinforcing member in the first embodiment of the present invention.

FIG. 3 is an explanatory view corresponding to a plan view showing a beam, an earthquake-resistant intermediate column, and a bearing reinforcing member in the first embodiment of the present invention.

FIG. 4 is an explanatory view corresponding to a side view showing a beam, an earthquake-resistant intermediate column, and a bearing reinforcing member in the first embodiment of the present invention.

FIG. 5 is an explanatory view corresponding to a front view showing an intermediate pillar joint in the first embodiment of the present invention.

FIG. 6 is an explanatory view corresponding to a plan view showing an intermediate joining portion in the first embodiment of the present invention.

FIG. 7 is an explanatory view showing a case where a beam yielding type yield hinge is generated on a beam on each floor and a column yielding type yield hinge is generated on an earthquake-resistant intermediate column on each floor when the frame is ultimately subjected to a proof stress according to the present invention.

FIG. 8 shows details of the bending moment due to the horizontal force when a beam yielding type yield hinge is generated on a beam on each floor at the time of ultimate strength of the frame and a column yielding type hinge is generated on an earthquake-resistant intermediate column on each floor. FIG.

FIG. 9 is a view showing a case where a beam yielding type yield hinge is generated on a beam on each floor at the time of ultimate strength of a frame according to the present invention, and a column yielding type hinge is generated on a seismic intermediate column on each floor. It is a detailed explanatory view of a bending moment of a beam and a column axial force of an earthquake-resistant intermediate column.

FIG. 10 is an explanatory view corresponding to a front view showing an intermediate column joint portion of an earthquake-resistant building structure according to a second embodiment of the present invention.

FIG. 11 is an explanatory view corresponding to a plan view showing an intermediate column joint of an earthquake-resistant building structure according to a second embodiment of the present invention.

FIG. 12 is an explanatory view corresponding to a front view showing a main part of an earthquake-resistant building structure according to a fourth embodiment of the present invention.

FIG. 13 is an explanatory view corresponding to a plan view showing a main part of an earthquake-resistant building structure according to a fourth embodiment of the present invention.

FIG. 14 is an explanatory view corresponding to a front view showing an earthquake-resistant building structure according to a fifth embodiment of the present invention.

FIG. 15 is an explanatory view corresponding to a front view showing a beam and an earthquake-resistant intermediate column in a conventional example.

FIG. 16 is an explanatory view corresponding to a plan view showing a beam and an earthquake-resistant intermediate column in a conventional example.

FIG. 17 is a detailed explanatory view showing a case where a beam yielding type yielding hinge is generated on a beam on each floor at the time of ultimate strength of a frame in a conventional example.

FIG. 18 is a detailed explanatory view of a change in bending moment due to a long-term vertical load of a beam on a lower floor when a beam yielding type hinge yields on a beam on each floor at the time of ultimate strength of a frame in a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Foundation 2 Column 3 Beam 4 Earthquake-resistant intermediate column 5 Bearing reinforcing member 6 Horizontal reinforcing plate 7 Shear panel reinforcing plate 8 Reinforced concrete member 9 Structural slit 10 Earthquake-resistant wall 11 Brace

Claims (8)

[Claims] 1. A pillar, a beam, and a skeleton provided with an earthquake-resistant intermediate column, the column is erected on a foundation, the earthquake-resistant intermediate column is erected on an intermediate portion of the span of the beam, and the column and the beam are provided. A reinforced concrete structure, and the quake-resistant intermediate pillar is made of a steel frame. 2. The earthquake-resistant building structure according to claim 1, wherein a cross-sectional width of the seismic intermediate column at a joint between the beam and the seismic intermediate column is smaller than a concrete cross-sectional width of the beam. An earthquake-resistant building structure, characterized in that an intermediate column extends up and down the floor through the concrete section of the beam. 3. The aseismic building structure according to claim 1, wherein the beam and the aseismic intermediate column form a rigid joint by the concrete bearing strength of the beam. Earthquake-resistant building structure. 4. The earthquake-resistant building structure according to claim 3, wherein a bearing reinforcing member protrudes into the concrete cross section of the beam from the earthquake-resistant intermediate column. 5. The aseismic building structure according to claim 1, wherein the cross-section yield strength of the aseismic intermediate column is set at a position near a joint between the beam and the aseismic intermediate column at the time of ultimate strength of the frame. An earthquake-resistant building structure, wherein a column yielding type yield hinge is formed by making the sectional yield strength smaller than a beam. 6. The aseismic intermediate column according to claim 1, wherein a section compressive buckling strength of the aseismic intermediate column is made larger than an axial force generated in the aseismic intermediate column. The generated axial force is transmitted to the beam on the lower floor, wherein the building is an earthquake-resistant building structure. 7. The earthquake-resistant building structure according to any one of claims 1 to 6, wherein the intermediate columns are made of a very low yield point steel with high toughness. Building structure. 8. The aseismic building structure according to claim 1, wherein a steel member of the quake-resistant intermediate column is covered with a reinforced concrete member, and the reinforced concrete member and the reinforced concrete member of the beam are structured. A structural slit is provided in at least one of a column head and a column base of a reinforced concrete member covering the earthquake-resistant intermediate column in the vicinity of a joint between the beam and the earthquake-resistant intermediate column so as not to be integrally integrated. An earthquake-resistant building structure characterized by the following.