JP6373666B2 - Method for designing through hole of steel frame, and steel frame including through hole - Google Patents

Description

  The present invention relates to a method for designing a through hole of a steel frame, and a steel frame including the through hole.

  There are various techniques as a joining structure or a joining method of a reinforced concrete (RC) structure or a steel reinforced concrete (SRC) structure. For example, in Patent Document 1, in order to improve the buckling strength of a steel reinforced concrete column, a perforated portion is formed in a steel web, and a U-shaped reinforcing bar formed in a U-shape is inserted into the perforated portion. From the side, the U-shaped reinforcing bars are inserted into the perforated part so that the U-shaped reinforcing bars overlap with each other, and the steel web is positioned in the center of the overlapping part, and close to the steel flange. Thus, it is disclosed that a U-shaped reinforcing bar is arranged so as to surround the flange. Moreover, in Patent Document 2, it was necessary to insert a reinforcing bar into a perforated part provided in a steel material, and to secure about 30 to 40 times the diameter of the reinforcing bar as a fixing length of the reinforcing bar to the column. Is disclosed. Patent Document 2 discloses that the fixing length can be made 10 times or less the diameter of the reinforcing bar by strongly restraining the reinforcing bar in the concrete. Patent Document 3 discloses that the reinforcing bars are inserted so that the ends of the reinforcing bars overlap with each other from the left and right of the perforated portion of the web steel plate in order to omit the welding operation of the joint portion of the reinforcing bars.

Japanese Patent No. 3943252 JP 2000-73496 A Japanese Patent No. 3611473

There is a technique in which a through hole is formed in a steel web, and two reinforcing bars are passed through the through hole to form a lap joint. In the conventional lap joint, the diameter of the through hole was designed to be larger than that of two reinforcing bars. For example, if the outermost diameter of one reinforcing bar is D1 and the outermost diameter of the other reinforcing bar is D2, the hole diameter φ of the through hole can be calculated by the following equation. α is a correction value for forming a gap between the hole diameter and the reinforcing bar, and can be set to 2 to 3 mm, for example.
φ = D1 + D2 + α

  On the other hand, for example, when two or more through holes are formed in one web, the minimum interval between adjacent through holes is proportional to the hole diameter. Moreover, it is common to provide a restriction on the ratio (cross-sectional defect ratio) between the total length of the diameters (diameters) of a plurality of through holes arranged in the vertical direction and the web height. Therefore, when the hole diameter is increased, the number of steps of reinforcing bars (for example, shear reinforcing bars) is restricted, and there may be a case where a lap joint cannot be formed.

  In view of the above-described problems, an object of the present invention is to provide a technique for maintaining the strength of a reinforcing bar and reducing the diameter of a through hole of a steel frame web as compared with the conventional technique.

In the present invention, in order to solve the above-described problem, at least one of the reinforcing bars that pass through the through hole is used as a binding bar, and the sum of the cross-sectional areas of the reinforcing bars constituting the binding bar is the same as that of the originally designed reinforcing bar. The hole diameter of the through hole was designed so as not to be smaller than the cross-sectional area and so that the hole diameter of the through hole was smaller than the original designed hole diameter.

  Specifically, the present invention is a method for designing a through hole of a steel frame provided in a steel web of a steel reinforced concrete structure, which is based on the outer diameters of two reinforcing bars that are wrapped and passed through the through hole of the steel frame. An original design process for obtaining the hole diameter of the through-hole of the steel frame and obtaining the cross-sectional area of the reinforcing bar, and at least one of the reinforcing bars that pass through the through-hole of the steel frame is a bundled bar that bundles a plurality of reinforcing bars. The hole diameter is set so that the sum of the cross-sectional areas of the bundled bars does not fall below the cross-sectional area of the reinforcing bars acquired in the original design process, and the hole diameter of the through hole of the steel frame is smaller than the hole diameter acquired in the original design process. Modification processing to design. A computer may perform the design method of the through hole of the steel frame.

  By designing the diameter of the through-holes to be smaller than the hole diameter calculated in the original design process (hereinafter also referred to as the reference diameter), for example, the interval between the through-holes can be made narrower than before, and the through-holes provided in the steel web The degree of freedom in design such as position is further improved. Further, since the number of reinforcing bars that can be passed through the through hole per web increases and the cross-sectional area of the reinforcing bars can be increased, the reinforcing bars can be firmly fixed to the concrete. In addition, since the through hole can be designed to be smaller than the reference diameter, the cross-sectional defect of the steel frame can be reduced as compared with the case of using the reference diameter. Further, the tensile strength of the reinforcing bars can be ensured by preventing the sum of the cross-sectional areas of the binding bars from being less than the cross-sectional area of the reinforcing bars calculated in the original design process.

  Further, in the method for designing a through hole of a steel frame according to the present invention, in the original design process, a circumference of two reinforcing bars that are wrapped and passed through the through hole of the steel frame is obtained, and in the correction process, the bundled bar The hole diameter may be designed so that the sum of the perimeters does not fall below the perimeter of the reinforcing bars calculated in the original design process. Thereby, the adhesive force of a reinforcing bar can be raised.

  Here, this invention can also be specified as a design apparatus of the through-hole of a steel frame. For example, the present invention is a design device for a through hole of a steel frame provided in a steel web of a steel reinforced concrete structure, and is based on the outer diameter of two rebars that are wrapped and passed through the through hole of the steel frame. Calculate the hole diameter of the through-hole, and calculate the cross-sectional area of the reinforcing bar, and at least one of the reinforcing bars that pass through the through-hole of the steel frame as a bundled bar that bundles a plurality of reinforcing bars, The hole diameter is such that the sum of the cross-sectional areas of the bundled bars does not fall below the cross-sectional area of the reinforcing bars calculated by the original design processing unit, and the hole diameter of the through hole of the steel frame is smaller than the hole diameter calculated by the original design processing unit And a correction processing unit for designing

  Moreover, this invention can also be specified as a design program of the through-hole of a steel frame. For example, the present invention is a design program for a through hole of a steel frame provided in a steel web of a steel reinforced concrete structure, and the structure of the steel frame is based on the outer diameter of two rebars that are wrapped and passed through the through hole of the steel frame. The original design step of calculating the hole diameter of the through-hole and calculating the cross-sectional area of the reinforcing bar, and at least one of the reinforcing bars that pass through the through-hole of the steel frame as a binding bar that bundles a plurality of reinforcing bars, Design the hole diameter so that the sum of the cross-sectional areas of the bundle bars does not fall below the cross-sectional area of the reinforcing bars calculated in the original design step, and the hole diameter of the through hole of the steel frame is smaller than the hole diameter calculated in the original design step You may make it make a computer perform the process containing a correction step.

  The present invention can also be specified as a recording medium on which the program is recorded. In this case, the function can be provided by causing a computer or the like to read and execute the program of the recording medium. Note that a computer-readable recording medium is a recording medium that accumulates information such as data and programs by electrical, magnetic, optical, mechanical, or chemical action and can be read from a computer or the like. Say.

Here, in the above-described method for designing a through hole of a steel frame according to the present invention, a through hole is formed in a steel web, and two reinforcing bars are passed through the through hole to design a lap joint. Can be suitably used. Moreover, the design method of the through-hole of the steel frame which concerns on this invention is the joining structure of the steel reinforced concrete structure which the linear 2nd structure to which the said 1st structure and the said 1st structure are connected joins. It can use suitably for the design of the through-hole of this web.

  The joint structure of the steel reinforced concrete structure is a steel frame of the second structure, and a steel frame having a through hole through which the reinforcing bar of the first structure passes through the web of the steel frame, and the reinforcing bar of the first structure The reinforcing bar of the first structure is positioned on the opposite side of the linear reinforcing bar with the end portion passing through the through hole and the linear reinforcing bar with respect to the web, and passes through the through hole. You may have a fixed reinforcing bar containing the linear wrap area | region connected with the edge part of a linear reinforcing bar, and the deformed fixing area | region connected to the said wrap area | region.

In the joint structure, the reinforcing bar of the first structure is constituted by a linear reinforcing bar and a fixing reinforcing bar. The fixing reinforcing bar is located on the opposite side of the linear reinforcing bar with respect to the steel web, and can be passed through the through hole of the steel web from the opposite side of the linear reinforcing bar. Therefore, for example, as the first structure, it is not necessary to pass a long reinforcing bar bent in an L shape through the through-hole of the web, so that workability is improved. Further, the end portion of the linear reinforcing bar of the first structure and the wrapping region of the fixing reinforcing bar are connected through the through hole of the steel web and are located in the concrete sandwiched between the flanges of the steel frame. Therefore, the reinforcing bar of the first structure is firmly fixed to the concrete. In particular, the fixing region of the fixing reinforcing bar is deformed, and when a tensile force acts on the linear reinforcing bar, the proportion of the tensile force in the same direction of the fixing reinforcing bar generated through the concrete in the lap region is increased. Can do. From the principle of action and reaction, the tensile force of the fixing reinforcing bar acts as a reaction force in the opposite direction to the tensile force acting on the linear reinforcing bar, that is, as a fixing force. The above relationship can be expressed as an expression as follows.
Tensile force acting on linear reinforcing bars = Tensile force generated on anchored reinforcing bars through the lap region + Compression force resisting web + Adhesive force on surrounding concrete

  The first structure and the second structure include columns, beams, girders, and the like. The above-mentioned joint structure includes a so-called cross-shaped joint including a case where there is a step in the vertical direction of the beam, a toroidal joint, a T-shaped joint, an L-shaped joint, a cantilever joint, a column, a beam, The present invention can be applied to a joint where structures such as girders are joined. Moreover, the said joining structure is applicable to the structure which contains a steel frame in a 2nd structure. In other words, the second structure is preferably made of SRC, but the first structure may be made of RC instead of SRC. The structure may be a civil engineering structure as well as a building structure.

  Moreover, this invention can also be specified as a steel frame containing a through-hole. For example, the present invention is a steel frame provided in a steel web of a steel reinforced concrete structure and including a through-hole designed to pass at least two reinforcing bars in the original design, wherein at least one reinforcing bar is a plurality of reinforcing bars. Designed so that the sum of the cross-sectional areas of the bundling bars does not fall below the cross-sectional area of one reinforcing bar in the original design, and the hole diameter of the through hole is smaller than the hole diameter of the original design It is a steel frame containing the made through-hole.

  By designing the hole diameter of the through holes to be smaller than the original designed hole diameter (hereinafter also referred to as the reference diameter), for example, the interval between the through holes can be made narrower than before, such as the position of the through holes provided in the steel web. More freedom in design. Since the number of reinforcing bars that can be passed through the through hole per web increases and the cross-sectional area of the reinforcing bars can be increased, the reinforcing bars can be firmly fixed to the concrete. In addition, since the through hole can be designed to be smaller than the reference diameter, the cross-sectional defect of the steel frame can be reduced as compared with the case of using the reference diameter. Moreover, the tensile strength of a reinforcing bar can be ensured by designing so that the sum of the cross-sectional areas of the bundled bars does not fall below the cross-sectional area of the originally designed reinforcing bars.

  ADVANTAGE OF THE INVENTION According to this invention, the technique which maintains the intensity | strength of a reinforcing bar and makes the hole diameter of the through-hole of a steel-frame web smaller than before can be provided.

FIG. 1 shows a cross-sectional view of a steel reinforced concrete column according to the first embodiment. FIG. 2 shows the configuration of a steel through-hole design device according to the first embodiment. FIG. 3 shows a design processing flow of the through hole of the steel frame according to the first embodiment. FIG. 4 shows the outer diameter, cross-sectional area, perimeter, and hole diameter of the reinforcing bar according to the original design. FIG. 5 shows the relationship between the through hole for the U-shaped reinforcing bar and the inserted U-shaped reinforcing bar. FIG. 6 shows a total cross-sectional area, a total perimeter, a hole diameter, and the like when a bundled line is used. FIG. 7 is a perspective view of a multilayer building including the joint structure according to the second embodiment. FIG. 8: shows an example of the top view of the multilayer building containing the joining structure which concerns on 2nd Embodiment. FIG. 9 shows an enlarged view of the AA cross section of FIG. FIG. 10 shows a principle diagram of the joint structure according to the second embodiment. FIG. 11 shows a bonding method of the bonding structure according to the second embodiment. FIG. 12 shows a cross-sectional view of a steel reinforced concrete column according to the third embodiment.

<First Embodiment>
<< Configuration of multi-layer building >>
FIG. 1 shows a cross-sectional view of a steel reinforced concrete column according to the first embodiment. Such a pillar 101 is, for example, a pillar of a multi-layered building such as an SRC apartment or commercial building. Hereinafter, a method for designing a through hole of a steel frame constituting such a steel reinforced concrete column will be described as an example.

  The pillar 101 has a cruciform steel frame 103 that is crossed in the shape of a cross in the center, and column main bars 104 extending in the vertical direction around the cruciform steel frame 103 at a predetermined interval inside the surface of the pillar 101 having a square cross section. Multiple are arranged with a gap. The column main bars 104 are arranged to form a square as a whole, and an annular stirrup 105 is arranged along the column main bars 104.

  The cross-shaped steel frame 103 is formed integrally by crossing an H-shaped steel web in a cross shape, and includes a cross-shaped steel web 133 and a cross-shaped steel flange 131. One web 133 of the cross-shaped steel frame 103 is provided with two through holes 134 for the U-shaped reinforcing bars through which the tips of the U-shaped reinforcing bars 151 and 152 pass at the same height. The other web 133 of the cross-shaped steel frame is also provided with two through holes 134 for the U-shaped reinforcing bars through which the U-shaped reinforcing bars 151 and 152 pass at the same height. However, the through-hole 134 for one U-shaped reinforcing bar of the cross-shaped steel frame and the through-hole 134 for the other U-shaped reinforcing bar of the cross-shaped steel frame are interfered by the U-shaped reinforcing bars 151 and 152 passing through each through-hole. In order to avoid this, the height positions are different.

  Each of the U-shaped reinforcing bars 151 and 152 has a U-shaped shape, and the tip portions of the two opposing U-shaped reinforcing bars 151 and 152 pass through the through hole 134 for the U-shaped reinforcing bar of the cross-shaped steel frame 103 and wrap. doing. The U-shaped reinforcing bars 151 and 152 are provided close to the flange 131 of the cruciform steel frame so as to surround the flange 131 of the cruciform steel frame.

  In the first embodiment, at least one of the opposing U-shaped reinforcing bars 151 and 152 is formed by a bundled bar. Therefore, the hole diameter of the through hole 134 for the U-shaped reinforcing bar is designed to be smaller than the conventional hole diameter (reference diameter).

<< Steel through-hole design device >>
FIG. 2 shows the configuration of the steel through-hole design apparatus 201 according to the first embodiment. A steel through-hole design device 201 (hereinafter also simply referred to as a design device) is configured by, for example, a general-purpose computer, and includes an information processing device 204 having a CPU 202 (central processing unit) and a memory 203, a keyboard, and a mouse. A device 205 and a display device 206 including a display are provided. The input device 205 receives information input and various setting operations. The CPU 202 executes a design program for the through hole of the steel frame stored in the memory 203, and the hole diameter of the through hole of the steel frame (the through hole 134 for the U-shaped reinforcing bar in the first embodiment) based on the outer diameter of the rebar and the like. Is calculated. The design device 201 may be configured by a tablet terminal or a mobile terminal. Computers, tablet terminals, and portable terminals only accept information and display calculation results. The diameter of the through-holes in the steel frame is set on the computer, tablet terminal, and server connected to the portable terminal via the network. It may be calculated. In this case, the calculation result can be transmitted to a computer, a tablet terminal, and a mobile terminal connected via a network.

<< Design process >>
FIG. 3 shows a design processing flow of the through hole of the steel frame according to the first embodiment. This process is started by starting a design processing program for a through-hole of a steel frame. In step S01, the design apparatus 201 executes an original design process. Specifically, the design device 201 wraps and passes the outer diameter (for example, nominal size) of the two reinforcing bars (co-shaped reinforcing bars 151 and 152) that are wrapped and passed through the through-holes of the steel frame (through holes 134 for the U-shaped reinforcing bars). The diameter (for example, the outermost diameter) of the through hole of the steel frame is acquired based on the diameter). In addition, the design device 201 acquires the cross-sectional area of the reinforcing bars (co-shaped reinforcing bars 151 and 152), the circumferential length of the reinforcing bars, and the hole diameter (reference diameter).

Here, FIG. 4 shows the outer diameter, cross-sectional area, circumferential length, and hole diameter of the reinforcing bar by the original design. In FIG. 4, the outermost diameter of the reinforcing bar, the cross-sectional area of the reinforcing bar, the circumferential length of the reinforcing bar, and the hole diameter of the through hole are shown for each nominal diameter. A table corresponding to FIG. 4 is stored in the memory 203 in advance, and the design apparatus 201 accepts an input of a nominal diameter, accesses the table, and has the outermost diameter of the reinforcing bar, the cross-sectional area of the reinforcing bar, the peripheral length of the reinforcing bar, and the through hole. Can be obtained. The cross-sectional area of the reinforcing bar, the circumferential length of the reinforcing bar, and the hole diameter of the through-hole may be calculated. For example, assuming that the outermost diameter of one reinforcing bar (co-shaped reinforcing bar 151) is D1, and the outermost diameter of the other reinforcing bar (co-shaped reinforcing bar 152) is D2, a through hole (through hole 134 for the co-shaped reinforcing bar). Can be calculated by the following formula: α is a correction value for forming a gap between the hole diameter and the reinforcing bar, and can be set to 2 to 3 mm, for example. Proceed to step S02.
φ = D1 + D2 + α

  In step S02, the design apparatus 201 executes a correction process. Specifically, the design apparatus 201 bundles a plurality of reinforcing bars with at least one reinforcing bar out of the reinforcing bars (co-shaped reinforcing bars 151 and 152) passed through the through-holes of the steel frame (through holes 134 for the U-shaped reinforcing bars). The sum of the cross-sectional areas of the binding bars is not less than the cross-sectional area of the reinforcing bars acquired in the original design process, and the hole diameter of the through hole of the steel frame is smaller than the hole diameter acquired in the original design process. Design the hole diameter. Here, FIG. 5 shows the relationship between the through-hole of a steel frame and the reinforcing bar inserted. The design device 201 displays an image corresponding to FIG. 5 on the display device 206, and via the input device 205, the type of the binding line (for example, (a), (b), (c), (d) of FIG. )) May be accepted.

  FIG. 5A shows a case in which the wrapping reinforcing bars 6 and 7 (for example, the U-shaped reinforcing bars 151 and 152) are passed through the through holes 34 (for example, the through holes 134 for the U-shaped reinforcing bars) one by one. Indicates. FIG. 5A is based on the original design, and the hole diameter in this case becomes the reference diameter of the original design.

  FIG. 5B shows that one reinforcing bar 6 (for example, a U-shaped reinforcing bar 151) is one, and the other reinforcing bar 7 (for example, a U-shaped reinforcing bar 152) is a bundled bar 7a in which two reinforcing bars are bundled. 7a is shown. By configuring the other reinforcing bar 7 with the bundling bars 7a and 7a, the hole diameter of the through hole 34a is smaller than the reference diameter indicated by the dotted line. In addition, since the tensile strength of a reinforcing bar can be calculated | required from the cross-sectional area of a reinforcing bar (for example, notarized cross-sectional area of a deformed reinforcing bar), the sum of the cross-sectional areas of the reinforcing bars constituting the bundled bars 7a and 7a is the other of the original design. It is necessary to design so as not to be smaller than the cross-sectional area of the reinforcing bar 7. Further, since the adhesion force of the reinforcing bars can be obtained from the circumferential length of the reinforcing bars (for example, the notarized circumferential length of the deformed reinforcing bars), the sum of the circumferential lengths of the reinforcing bars constituting the binding bars 7a and 7a is the other of the original design. It is necessary to design so as not to fall below the circumference of the reinforcing bar 7.

  FIG. 5 (c) shows that the reinforcing bars 6 and 7 (for example, the U-shaped reinforcing bars 151 and 152) are the binding bars 6a and 7b in which two reinforcing bars are bundled, and one reinforcing bar 6 (for example, the U-shaped reinforcing bar). A case is shown in which the bundle reinforcing bars 6a constituting the reinforcing bars 151) and the reinforcing bars 7b constituting the other reinforcing bars 7 (for example, the U-shaped reinforcing bars 152) have the same diameter. By configuring the two reinforcing bars 6 and 7 (for example, the U-shaped reinforcing bars 151 and 152) by the bundled bars 6a and 7b, the hole diameter of the through hole 34b is smaller than the reference diameter indicated by the dotted line. . In order to secure the tensile strength of the reinforcing bars, it is necessary to design so that the sum of the cross-sectional areas of the reinforcing bars constituting the binding bars 6a and 7b does not fall below the cross-sectional area of the originally designed reinforcing bars 6 and 7. Moreover, in order to ensure the adhesive strength of the reinforcing bars, it is necessary to design the sum of the peripheral lengths of the reinforcing bars constituting the bundled bars 6a and 7b so as not to fall below the peripheral length of the two reinforcing bars 6 and 7 of the original design. .

  In FIG. 5D, one reinforcing bar 6 (for example, the U-shaped reinforcing bar 151) is a binding bar 6a, 6b obtained by binding two reinforcing bars, and the other reinforcing bar 7 (for example, the U-type reinforcing bar 152) is 2 A case where the reinforcing bars 7a and 7b are formed by binding the reinforcing bars of the book, the diameters of the binding bars 6a and 6b of one reinforcing bar 6 are made different, and the diameters of the binding bars 7a and 7b of the other reinforcing bar 7 are made different is shown. . The diameters of the binding muscles 6a and 7a are the same, and the diameters of the binding muscles 6b and 7b are the same. By configuring as described above, the hole diameter of the through hole 34c is smaller than the reference diameter indicated by the dotted line. In addition, in order to ensure the tensile strength of the reinforcing bars, the sum of the cross-sectional areas of the reinforcing bars constituting the one reinforcing bars 6a and 6b and the other binding bars 7a and 7b is the linear reinforcing bar 6 and the fixing reinforcing bar 7 of the original design. It is necessary to design so as not to be less than the cross-sectional area. In addition, in order to secure the adhesion of the reinforcing bars, the sum of the circumferences of the reinforcing bars constituting the binding bars 6a and 6b of one reinforcing bar 6 and the binding bars 7a and 7b of the other reinforcing bar 7 is one reinforcing bar 6 of the original design. And it is necessary to design so that it may not fall below the circumference of the other reinforcing bar 7.

  Here, FIG. 6 shows a total cross-sectional area, a total perimeter, a hole diameter, and the like in the case of using a binding line. In FIG. 6, the total cross-sectional area and cross-sectional area ratio of the bundled muscles, the total circumference and circumference ratio of the bundled muscles, and the hole diameter and the hole diameter ratio when the bundled muscles are used for each bundled muscle when the bundled muscles are adopted. It is shown. The binding bars “2-D10”, “2-D13”, “2-D16”, and “2-D19” have one reinforcing bar 6 (for example, a U-shaped reinforcing bar 151) as shown in FIG. And the other reinforcing bar 7 (for example, the U-shaped reinforcing bar 152) are the binding bars 6a and 7b in which two reinforcing bars are bundled, and the binding bars 6a and 6a constituting one reinforcing bar 6 and the other reinforcing bar 7 A case where the reinforcing bar diameters of the bundling bars 7b and 7b constituting the same are made the same. As shown in FIG. 5 (d), the binding bar “D13 + D16” has one reinforcing bar 6 as a binding bar 6a, 6b in which two reinforcing bars are bundled, and the other reinforcing bar 7 as a binding bar 7a in which two reinforcing bars are bundled. 7b, and the diameters of the binding bars 6a, 6b of one reinforcing bar 6 are made different, and the diameters of the binding bars 7a, 7b of the other reinforcing bar are made different. The diameters of the binding muscles 6a and 7a are the same, and the diameters of the binding muscles 6b and 7b are the same.

  The table corresponding to FIG. 6 is stored in the memory in advance, and the design apparatus 201 receives input of the type of the binding line, accesses the table, and accesses the table to determine the total cross-sectional area of the binding line, the cross-sectional area ratio, and the total circumference of the binding line. Further, it is possible to obtain the circumference ratio and the hole diameter and the hole diameter ratio in the case where the bundling muscle is used. The total perimeter of the bundling bars, the circumference ratio, and the hole diameter and hole diameter ratio when the bundling bars are used may be calculated.

For example, in the case of calculation, in the original design process, when the nominal diameter of one reinforcing bar 6 (for example, the U-shaped reinforcing bar 151) and the other reinforcing bar 7 (for example, the U-shaped reinforcing bar 152) is D16, the through hole 34 is used. The hole diameter of the through hole 134 (for example, the U-shaped reinforcing bar) is 38 mm.
Hole diameter = D (outer diameter) x 2 + α (interval)

On the other hand, when the bundled line (2-D13) is used, the hole diameter of the through hole 34b (for example, the through hole 134 for the U-shaped reinforcing bar) is 34 mm. r indicates the radius of the bunches 6a and 7b.
Pore size = 2r + 2 × 2r / √2

Then, the design device 201 may display the calculation result on the display device 206. For example, in the design apparatus 201, the hole diameter of the through hole 34c when the bundled bars 6a and 7b are used is 34 mm, which is lower than the hole diameter 38 mm of the original design (hole diameter ratio: 0.89), and the hole diameter of the through hole 34 is the original design. To the effect that it can be made smaller. Further, the display device 206, bundled muscle 6a, the total cross-sectional area of 7b is 254 mm ^2, greater than the cross-sectional area 199Mm ² of the original design rebar (co type Reinforcement) (sectional area ratio: 1.28), rebar Displays that the tensile strength has increased. In addition, the design device 201 has a total perimeter of the bundling bars 6a and 7b of 80 mm, which exceeds the perimeter of the originally designed reinforcing bar (co-shaped reinforcing bar) 50 mm (peripheral length ratio: 1.60). The fact that the adhesive force of the is increasing is displayed. In other words, this means that the length of the bundling line can be shortened when the adhesive force is equal to that of the original design.

<Effect>
By designing the through hole (through hole 134 for the U-shaped reinforcing bar) formed in the web of the steel frame (cross-shaped steel frame 103) to be smaller than the reference diameter, for example, the through hole (through hole for the U-shaped reinforcing bar) 134) the distance between them can be made narrower than before, and the degree of freedom in design, such as the position of the through hole (through hole 134 for U-shaped reinforcement) provided in the web of the steel frame (cross-shaped steel frame 103), is further improved. Further, in order to ensure the tensile strength of the reinforcing bars, the sum of the cross-sectional areas of the reinforcing bars constituting the binding bars 6a and 7b is designed not to be lower than the cross-sectional area of the originally designed reinforcing bars (co-shaped reinforcing bars 151 and 152). By doing so, the strength of the multi-layered building can be improved to be equivalent to the original design. Moreover, in order to ensure the adhesive strength of a reinforcing bar, it is designed so that the sum of the peripheral lengths of the reinforcing bars constituting the bundled bars does not fall below the peripheral length of the originally designed reinforcing bars (co-shaped reinforcing bars 151, 152). The strength of the pillar 101 of the multi-layer building can be improved or equal to the original design. Further, since the through hole (through hole 134 for reinforcing the U-shaped reinforcing member) can be designed to be smaller than the reference diameter, the cross-sectional defect of the steel frame can be reduced as compared with the case of using the reference diameter. As a result, the strength of the multi-layered building can be improved to be equivalent to the original design.

Second Embodiment
FIG. 7 is a perspective view of a multilayer building including the joint structure according to the second embodiment. FIG. 8: shows an example of the top view of the multilayer building containing the joining structure which concerns on 2nd Embodiment. FIG. 9 shows an enlarged view of the AA cross section of FIG.

  The through-hole design method described in the first embodiment can be applied to a multilayer building M described below. The multi-layered building M is assumed to be a building structure such as an SRC apartment or commercial building, and is composed of a plurality of floors. In the following description, as shown in FIGS. 8 and 9, a column beam joint in which the ends of a large beam 2 extending in the beam direction and a large beam 21 extending in the inter-beam direction are connected to a column (outer column) 1 extending in the vertical direction. A through hole 34 is formed in the web 33 of the steel frame 3 that constitutes the joining structure 10 of a so-called toroidal joint.

Note that the bonding structure 10 is not limited to the above. The joint structure 10 can be suitably used for a joint where beams, columns and beams, columns and girders, etc. are joined in a T shape. Such a joint includes a joint where the uppermost beam and column are connected in a T shape (for example, a T-shaped joint), a joint where a large beam and a small beam are connected in a T shape, an outer column and a piece. Examples include a joint where a cantilever (such as a balcony) is connected in a T shape. In addition, the structure connected to the structure containing a steel frame should just be a structure containing a reinforcing bar, and may be either SRC structure or RC structure. Moreover, you may apply the joining structure 10 to a civil engineering structure other than a building structure.

  A large beam 2 (corresponding to the second structure of the present invention) extending in the girder direction has an H-shaped steel frame 3 disposed at the center, and a main beam (main reinforcing bar) 4 of the large beam extending in the girder direction around the steel frame 3 has a cross section. A plurality of beams are arranged at predetermined intervals inside the surface of the large beam 2 having a rectangular shape. The main beam 4 of the large beam extending in the girder direction is arranged so as to form a rectangle as a whole, and an annular stirrup 5 is arranged along the main beam 4 of the large beam extending in the beam direction. Deformed bars are used for the main bars 4 of the large beams extending in the girder direction. The diameter of the main bars 4 of the large beams extending in the girder direction and the interval between the main bars 4 are appropriately designed according to the multilayer building M. The diameter of the star wrap 5 and the interval between the star wraps 5 are also appropriately designed according to the multilayer building M.

The steel frame 3 according to the second embodiment is H-shaped as described above, and includes a rectangular web 33 and rectangular flanges 31 and 32 that are connected to both ends of the web 33 at right angles to the web 33. ing. The flanges 31 and 32 are opposed to each other. The web 33 is provided with two through holes 34 in the vertical direction through which a part of the main bar 40 of the large beam 21 (the first structure of the present invention) extending in the inter-beam direction. The through-hole 34 is circular and has a hole diameter through which the linear reinforcing bar 6 and the fixing reinforcing bar 7 constituting the main reinforcing bar 40 of the large beam 21 extending in the beam-to-beam direction pass. This hole diameter corresponds to the reference diameter of the present invention. For example, if the outermost diameter of the linear reinforcing bar 6 is D1 and the outermost diameter of the fixing reinforcing bar 7 is D2, the hole diameter φ of the through hole can be calculated by the following equation. α is a correction value for forming a gap between the hole diameter and the reinforcing bar, and can be set to 2 to 3 mm, for example. In the second embodiment, D1 = D2.
φ = D1 + D2 + α

  The main beam 40 of the large beam extending in the beam-to-beam direction has a two-level bar at each of the upper and lower bars. The upper reinforcing bar 61 at the upper end and the lower reinforcing bar 61 at the lower end are both L-shaped and are arranged outside the steel frame 3 and inside the stirrup 5. Further, two reinforcing bars located between the upper reinforcing bar 61 of the upper end and the lower reinforcing bar 61 of the lower end, that is, the lower reinforcing bar of the upper end and the upper reinforcing bar of the lower end (the first structure of the present invention). (Corresponding to a reinforcing bar of the body) is composed of a linear reinforcing bar 6 and a fixing reinforcing bar 7 and is inserted into through-holes 34 which are drilled at intervals in the vertical direction. Both the linear reinforcing bar 6 and the fixing reinforcing bar 7 are deformed reinforcing bars. The end of the linear reinforcing bar 6 is passed through the through hole 34 and connected to the wrap region of the fixing reinforcing bar 7. A tie wire 8 is used for connection. The connection is made at two locations on the inner side (straight reinforcing bar side) and the outer side (fixed reinforcing bar side) with the web 33 as a reference. In the first embodiment, the fixing regions 71 of the fixing reinforcing bars 7 are arranged so as to face each other. The fixing reinforcing bars 7 can be appropriately changed so as not to interfere with each other.

  The fixing reinforcing bar 7 has an L shape as a whole, and a fixing region that is bent to the web side so that a linear wrap region 72 and a region where the linear wrap region 72 is extended are parallel to the web 33. 71. The length of the wrap region 72 is designed to be slightly shorter than the width of the flanges 31 and 32. The length of the fixing region 71 is designed to be shorter than the interval between the flanges 31 and 32. As a result, the fixing reinforcing bar 7 is located in the concrete sandwiched between the flanges 31 and 32 of the steel frame 3.

Here, FIG. 10 shows a principle diagram of the joint structure according to the second embodiment. When a tensile force B is applied to a part of the main reinforcement 40 of the large beam extending in the beam-to-beam direction, that is, the wrap region 72 of the linear reinforcing bar 6 and the fixing reinforcing bar 7, around the wrap region 72 of the linear reinforcing bar 6 and the fixing reinforcing bar 7. A shearing force C acts. Further, a compressive force D acts between the lap region 72 of the linear reinforcing bar 6 and the fixing reinforcing bar 7 and the web 33. The compressive force D acts as a force E2 that is perpendicular to the web 1 and parallel to the force E1 by vector decomposition of the force. The E1 pushes the web itself in an out-of-plane direction and pushes the opposite concrete through the web. E2 pushes the flanges 31, 32. On the other hand, since the flanges 31 and 32 are fixed, they exert a reaction to push back the concrete. As a result, the fixing property between the concrete and the linear reinforcing bars 6 and the fixing reinforcing bars 7 is improved.

  Further, a supporting pressure F that compresses particularly strong concrete acts between the corner portion positioned between the wrap region 72 and the fixing region 71 and the web 33. Further, an adhesion force G acts on the fixing region 71. By the support pressure F and the adhesion force G acting, the fixing property with the linear reinforcing bar 6 and the fixing reinforcing bar 7 is further improved.

<< Join method >>
FIG. 11 shows an example of a bonding method of the bonding structure according to the second embodiment. The joining method described below can be performed in the reinforcing bar assembling process after the steel frame assembling process of the multilayer building M is completed. However, the drilling process may be performed before the steel frame assembly process. By performing the through hole design process (original design process, correction process) described in the first embodiment before the drilling step, the hole diameter of the through hole can be designed.

  The design process will be briefly described. In the original design process (see FIG. 3) of the design process, the design apparatus 201 executes the original design process. Specifically, the design apparatus 201, based on the outer diameters (for example, nominal diameters) of two reinforcing bars (straight reinforcing bars 6 and anchoring reinforcing bars 7) wrapped and passed through the through-holes 34 of the steel frame, The hole diameter (for example, outermost diameter) of the through hole is acquired. Further, the design device 201 acquires the cross-sectional area of the reinforcing bars (the linear reinforcing bars 6 and the fixing reinforcing bars 7), the perimeter of the reinforcing bars, and the hole diameter (reference diameter).

  In the correction process of the meter process, the design device 201 uses at least one reinforcing bar among the reinforcing bars (the linear reinforcing bar 6 and the fixed reinforcing bar 7) to be passed through the through hole 34 of the steel frame as a binding bar obtained by binding a plurality of reinforcing bars. The hole diameter is designed so that the sum of the cross-sectional areas of the bundle bars does not fall below the cross-sectional area of the reinforcing bar acquired in the original design process, and the hole diameter of the through hole of the steel frame is smaller than the hole diameter acquired in the original design process. Thus, the hole diameter of the through hole is designed.

  In the drilling process, through holes 34 are formed in the steel web 33. Note that the perforating step may be performed before the steel frame is assembled or may be performed after the steel frame is assembled. In the reinforcing bar insertion step, the main beam 4 of the large beam extending in the direction between the beams is inserted into the through hole 34. A straight reinforcing bar 6, which is a part of the main beam 40 of the large beam extending in the inter-beam direction in the through hole 34, is inserted into the through hole 34 from the inside so that the end portion protrudes outward. On the other hand, the fixing reinforcing bar 7 is inserted into the through hole 34 so that the end protrudes inward from the side opposite to the linear reinforcing bar 6 with respect to the web 33 of the steel frame 3. It should be noted that either the straight reinforcing bar 6 or the fixing reinforcing bar 7 may be inserted into the through-hole 34 first, but the connecting of the fixing reinforcing bar 7 becomes easier when the linear reinforcing bar 6 is inserted first.

  Next, in the binding step, the end portions of the linear reinforcing bars 6 and the wrap regions 72 of the fixing reinforcing bars 7 are overlapped, and are bound (connected) by the binding wires 8. In the first embodiment, the webs 33 of the steel frame 3 are bound at one place on each of the inner side and the outer side. As described above, the joining of the joining structure according to the first embodiment is completed. Thereafter, a mold assembly process, a concrete placing process, a deframe process, and the like are performed, and the multilayer building M is constructed in units of layers.

<< Effect >>
According to the joint structure 10 according to the second embodiment, a part of the main reinforcing bar 40 of the large beam extending in the inter-beam direction is constituted by the linear reinforcing bar 6 and the fixing reinforcing bar 7. The fixing reinforcing bar 7 is located on the opposite side of the linear reinforcing bar 6 with respect to the web 33 of the steel frame 3, and can pass through the through hole 34 of the steel web 33 from the opposite side of the linear reinforcing bar 6. For this reason, for example, it is not necessary to pass a long reinforcing bar bent in an L shape as the main reinforcing bar 40 of the large beam extending in the inter-beam direction, so that workability is improved. Further, the end portion of the linear reinforcing bar 6 and the wrap region 72 of the fixing reinforcing bar 7 are passed through the through hole 34 of the web 33 of the steel frame 3, and are bound (connected) by the binding wire 8, and the flanges 31 and 32 of the steel frame 3. Located in concrete sandwiched between. Therefore, among the main reinforcing bars 40 of the large beams extending in the inter-beam direction, in particular, the linear reinforcing bars 6 and the fixing reinforcing bars 7 are strongly fixed to the concrete. Further, a particularly strong supporting force F acts between the corner portion positioned between the wrap region 72 and the fixing region 71 and the web 33 (see FIG. 10). Further, an adhesion force G acts on the fixing region 71 (see FIG. 10). By the support pressure F and the adhesion force G acting, the fixing property with the linear reinforcing bar 6 and the fixing reinforcing bar 7 is further improved.

  In addition, by designing the through holes 34 formed in the web of the steel frame 3 to be smaller than the reference diameter, for example, the interval between the through holes 34 can be made narrower than before, and the positions of the through holes 34 provided in the web of the steel frame 3 The degree of freedom in design is improved. In addition, in order to ensure the tensile strength of the reinforcing bars, it is designed so that the sum of the cross-sectional areas of the reinforcing bars constituting the binding bars 6a and 7b does not fall below the cross-sectional area of the originally designed reinforcing bars 6 and 7. The strength of the object M can be improved or equal to that of the original design. In addition, in order to ensure the adhesion of reinforcing bars, it is designed so that the sum of the perimeters of the reinforcing bars that make up the binding bars 6a, 7b does not fall below the perimeter of the originally designed reinforcing bars 6, 7. The strength of M can be improved to the same level as the original design. Moreover, since the through-hole 34 can be designed smaller than a reference diameter, the cross-sectional defect | deletion of a steel frame can be decreased compared with the case where it is set as a reference diameter. As a result, the strength of the multi-layered building M can be improved to be equivalent to the original design.

<Third Embodiment>
FIG. 12 shows a cross-sectional view of a steel reinforced concrete column according to the third embodiment. Such a pillar 101 'is a pillar of a multi-layered building such as an SRC condominium or a commercial building, for example, like the pillar 101 of the first embodiment. The column 101 ′ has a T-shaped steel frame 103 ′ that intersects in a T shape at the center, and a column main bar 104 that extends in the vertical direction around the T-shaped steel frame 103 ′ has a square shape in the cross-sectional view of the column 101 ′. A plurality are arranged inside the surface at a predetermined interval. The column main bars 104 are arranged to form a square as a whole, and an annular stirrup 105 is arranged along the column main bars 104.

  The T-shaped steel frame 103 ′ is formed by integrally crossing an H-shaped steel web in a cross shape, and includes a T-shaped steel web 133 ′ and a T-shaped steel flange 131 ′. . One web 133 ′ of the T-shaped steel frame 103 ′ is provided with one through-hole 134 for a U-shaped reinforcing bar through which the distal ends of the U-shaped reinforcing bars 151 and 152 pass. The other web 133 'of the T-shaped steel frame is provided with two through holes 134 for U-shaped reinforcing bars through which the U-shaped reinforcing bars 151 and 152 pass at the same height. Each of the U-shaped reinforcing bars 151 and 152 has a U-shaped shape, and the tip portions of the two opposing U-shaped reinforcing bars 151 and 152 form a through hole 134 for the U-shaped reinforcing bar of the T-shaped steel frame 103 ′. Wrapping the street. In the third embodiment, at least one of the opposing U-shaped reinforcing bars 151 and 152 is constituted by a bundled bar. Therefore, the hole diameter of the through hole 134 for the U-shaped reinforcing bar is designed to be smaller than the conventional hole diameter (reference diameter). The through hole design process is the same as in the first embodiment. Therefore, explanation is omitted.

By designing the through hole (through hole 134 for the U-shaped reinforcing bar) formed in the web of the steel frame (T-shaped steel frame 103 ') to be smaller than the reference diameter, for example, the through hole (for the U-shaped reinforcing bar) The interval between the through holes 134) can be made narrower than before, and the degree of freedom in design such as the position of the through holes (through holes 134 for U-shaped reinforcement) provided in the web of the steel frame (T-shaped steel frame 103 ') is further improved. . In addition, in order to ensure the tensile strength of the reinforcing bars, it is designed so that the sum of the cross-sectional areas of the reinforcing bars constituting the bundle reinforcing bars does not fall below the cross-sectional area of the originally designed reinforcing bars (co-shaped reinforcing bars 151, 152). The strength of the multi-layer building can be improved to the same level as the original design. Moreover, in order to ensure the adhesive strength of a reinforcing bar, it is designed so that the sum of the peripheral lengths of the reinforcing bars constituting the bundled bars does not fall below the peripheral length of the originally designed reinforcing bars (co-shaped reinforcing bars 151, 152). The strength of the pillar 101 'of the multi-layer building can be improved or equal to that of the original design. Further, since the through hole (through hole 134 for reinforcing the U-shaped reinforcing member) can be designed to be smaller than the reference diameter, the cross-sectional defect of the steel frame can be reduced as compared with the case of using the reference diameter. As a result, the strength of the multi-layered building can be improved to be equivalent to the original design.

  Although the preferred embodiments of the present invention have been described above, the present invention can be implemented by combining the embodiments as much as possible.

DESCRIPTION OF SYMBOLS 1 ... Outer pillar 2 ... Large beam extended in the direction of a girder 21 ... Large beam 3 extended in the direction between beams 3 ... Steel frame 31, 32 ... Flange 33 ... Web 34 ... Through-hole 4 ...・ Main bar 5 ... Star wrap 6 ... Linear reinforcing bar 7 ... Fixing reinforcing bar 71 ... Fixing area 72 ... Wrap area 8 ... Bundling wire 101 ... Column 103 ... Cross Type steel frame 104 ... Column main bar 105 ... Stirrup 133 ... Cross type steel web 134 ... Through holes 151, 152 for the U type reinforcement bars ... The U type reinforcement bars 201 ... Design device 202... CPU
203 ... Memory 204 ... Information processing device 205 ... Input device 206 ... Display device M ... Multi-layered building

Claims (3)

A method for designing a through hole of a steel frame provided in a steel web of a steel reinforced concrete structure,
An original design process for obtaining the hole diameter of the through-hole of the steel frame based on the outer diameter of the two reinforcing bars passed through the steel-frame through-hole, and obtaining the cross-sectional area of the reinforcing bar;
Among the reinforcing bars that pass through the through-holes of the steel frame, at least one reinforcing bar is a binding bar that bundles a plurality of reinforcing bars, and the sum of the cross-sectional areas of the binding bars does not fall below the cross-sectional area of the reinforcing bar obtained in the original design process, And the correction process which designs a hole diameter so that the hole diameter of the through-hole of the said steel frame becomes smaller than the hole diameter acquired by the original design process, The design method of the through-hole of a steel frame including the correction process. In the original design process, the circumference of the two reinforcing bars that are wrapped and passed through the through hole of the steel frame is obtained,
2. The method for designing a through-hole of a steel frame according to claim 1, wherein in the correction process, the hole diameter is designed so that the sum of the circumferences of the bundled bars does not fall below the circumference of the reinforcing bars calculated in the original design process. A steel frame comprising a through hole provided in a steel web of a steel reinforced concrete structure and designed to pass at least two rebars in the original design;
At least one rebar is a bundle of multiple rebars, the sum of the cross-sectional areas of the rebar is not less than the cross-sectional area of the single rebar in the original design, and the hole diameter of the through hole is the original design A steel frame including a through-hole designed to be smaller than the hole diameter.

Images