JP2015025288A - Column base reinforcement method and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve earthquake resistance of a column base of an existing building.SOLUTION: A first extension base plate 7 which is formed in a rectangular plate shape and has a cut part 8, shaped corresponding to a plane shape of an existing base plate 2, at an intermediate part of one long side, and a second extension base plate 9 in a rectangular plate state are welded to a periphery of the existing base plate 2 provided at a lower end part of a steel-made column base 1 and fixed to a foundation 4 through an existing anchor bolt 5. The respective extension base plates 7, 9 are fixed to the foundation 4 with a post-installed anchor bolt 10. A rib member 15 is fitted between the lower end part of the column base 1 and the respective extension base plates 7, 9. Shearing force and drawing force generated between the column base 1 of the building and the foundation 4 when an earthquake takes place is applied to the existing base plate 2 and existing anchor bolt 5, and transmitted from the lower end part of the column base 1 to the foundation 4 through a rib member 11, the respective extension base plates 7, 9, and the post-installed anchor bolt 10 to be born.

Description

  The present invention relates to a column base reinforcement method and apparatus used to reinforce a foundation joint portion of a column base in an existing building.

  Generally, in various plants, a steel frame structure (steel structure) made up of steel pillars, beam members, braces, and the like is often used as a stand for supporting equipment, piping, and the like.

  When installing this type of frame on the basis, a flat base plate is individually attached to the lower end of each column base by fixing means such as welding for each column base. Furthermore, foundations corresponding to the individual base plates are embedded in the ground in advance at positions below the respective column bases, and the base plates of the corresponding column bases are respectively attached to the respective foundations via anchor bolts. It is a fixed configuration.

  When a horizontal force acts on the frame during an earthquake, a horizontal shearing force acts between the base plate and the foundation at the foundation installation portion of each column base.

  Further, among the column bases, particularly in the column bases to which the braces are connected, when the braces are arranged obliquely downward along the action direction of the horizontal force due to the earthquake, the horizontal force due to the earthquake is reduced. Since it is transmitted to the column base as an obliquely downward force via the brace, a compressive force in the direction of pressing against the foundation (downward) is applied to the column base.

  On the other hand, in the column base to which the brace is connected, when the brace is arranged obliquely upward along the direction of the horizontal force due to the earthquake, the horizontal force due to the earthquake is obliquely upward through the brace. Therefore, a pulling force in a direction (upward) that separates from the foundation acts on the column base.

  Therefore, in the column base to which the brace is connected, the pulling force and the compressive force act alternately with the shaking at the time of the earthquake. A structure that can withstand the load of the pulling force is required.

  By the way, existing buildings are constructed to withstand a certain design load in accordance with the earthquake resistance standards at the time of construction, but in recent years, as a preparation for a large earthquake, In some cases, an earthquake resistance measure is required to withstand an earthquake having a greater seismic intensity (horizontal vibration) than that specified in the earthquake resistance standard.

  As one of the existing building reinforcement methods, for example, a method of reinforcing a pier in which concrete columns are integrally formed on a reinforced concrete footing embedded in the ground is proposed in the past. (For example, refer to Patent Document 1).

Japanese Patent Laid-Open No. 10-8422

  However, since the structure disclosed in Patent Document 1 is a reinforcing structure for a concrete pier formed integrally with a reinforced concrete footing, a steel column base like the above-mentioned frame is installed on the foundation. It cannot be applied as it is as the seismic reinforcement for improving the resistance to the shearing force and the pulling force.

  Therefore, a method for performing seismic reinforcement at the foundation installation portion of the column base in an existing building such as the above-mentioned frame, in particular, the above-described seismic reinforcement related to the shearing force and pulling-out force has not been proposed.

  Furthermore, the frame is often connected to the brace near the lower end of the column base, and is often configured to support the piping near the column base. The reality is that workability is poor.

  Therefore, the present invention is to improve the resistance against the shearing force and the pulling force acting during an earthquake on the foundation installation part of the column base in the existing building such as the frame, and to make it possible to perform seismic reinforcement with good workability. It is an object of the present invention to provide a column base reinforcing method and apparatus.

  In order to solve the above-mentioned problem, the present invention provides an existing installation which is provided at the lower end of a steel column base of an existing building and is fixed to the foundation via an existing anchor bolt, corresponding to claim 1 A first extension base plate having a shape corresponding to the planar shape of the existing base plate at a middle portion of one side around the base plate, and the one side of the first extension base plate A plate-like second extension base plate positioned on the side and a post-fixed anchor bolt for fixing each extension base plate to the foundation; a rib member attached between the lower end of the column base and each extension base plate; It is set as the column base reinforcement apparatus which has the structure provided with.

  Further, corresponding to claim 2, in the configuration of claim 1, the side of the second extension base plate in contact with the existing base plate is provided with a fitting recess for fitting one end edge of the existing base plate. The configuration is as described above.

  Corresponding to claim 3, there is a plate shape around an existing base plate provided at the lower end of a steel column base of an existing building and fixed to the foundation via an existing anchor bolt. A first extension base plate having a cutout portion corresponding to the planar shape of the existing base plate in the middle of one side, and a plate-like second extension located on the one side of the first extension base plate A base plate is arranged, and each extension base plate is fixed to the foundation via a post-fixed anchor bolt, each extension base plate is joined to the existing base plate, and each extension base plate is joined, A column base reinforcement method is provided in which a rib member is attached between the lower end portion of the leg and each of the additional base plates.

According to the present invention, the following excellent effects are exhibited.
(1) In the column base reinforcement device having the configuration described in claim 1, the existing anchor bolt is used to remove the shearing force and the pulling force generated between the column base and the foundation of the building during an earthquake. In addition to being transmitted to the foundation via the lower end of the column base, the rib member newly provided, each additional base plate, and the anchor bolt can be transmitted to and supported by the foundation. Therefore, the seismic reinforcement which improves the tolerance with respect to the above-mentioned shearing force and drawing-out force can be performed about the foundation installation part in the column base of the said existing building.
(2) The same effects as in (1) can be obtained also by the column base reinforcing method having the configuration shown in claim 3.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows an embodiment of a column base reinforcing method and apparatus according to the present invention. . The structure of the existing column base of the existing building which applies this invention is shown, (a) is a schematic plan view of the lower end part of a column base, (b) is a schematic side view. It is a schematic plan view of the lower end part of the column base which shows the other form of implementation of this invention.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

  FIGS. 1A, 1B and 2A, 2B show one embodiment of the column base reinforcing method and apparatus of the present invention.

  Here, first, with reference to FIG. 2 (a) (b), the structure of the existing steel column base 1 in the existing building which applies this invention is demonstrated.

  The existing column base 1 has a flat base plate 2 attached to the lower end, and the base plate 2 is fixed to a concrete base 4 embedded in the ground 3 via anchor bolts 5. is there. For convenience of explanation, the existing base plate 2 and the anchor bolt 5 are hereinafter referred to as the existing base plate 2 and the existing anchor bolt 5, respectively. In the figure, the column base 1 is shown as being made of H-shaped steel.

  The column base reinforcing device 6 of the present invention used for reinforcing the existing column base 1 is a rectangular plate as shown in FIGS. 1 (a), 1 (b) and 2 (a). A flat U-shaped first extension base plate 7 having a notch 8 having a shape corresponding to the planar shape of the existing base plate 2 in the middle of the long side, and the total length of the long side of the first extension base plate 7 A second extension base plate 9 having a rectangular plate shape extending along the line. Accordingly, when the second extension base plate 9 is arranged along one long side of the first extension base plate 7, the cutout portion 8 of the first extension base plate 7 and one side edge of the second extension base plate 9 An opening having a shape corresponding to the planar shape of the existing base plate 2 can be formed in the enclosed inner side.

  Furthermore, as shown in FIGS. 1A and 1B, the column base reinforcing device 6 according to the present invention has the first and second components around the existing base plate 2 on the upper surface of the foundation 4 as shown in FIGS. A plurality of post-installed anchor bolts (post-installed anchor bolts) 10 for fixing the respective extension base plates 7 and 9 and a plurality of rib members 11 are provided.

  When reinforcing the column base 1 of an existing building using the column base reinforcement device 6 of the present invention composed of the above-described components, first, the above-described upper surface of the foundation 4 on which the column base 1 to be reinforced is installed. Around the existing base plate 2, a plurality of post-fixed anchor bolts 10 are implanted at a certain interval in the circumferential direction. At this time, the post-cast anchor bolt 10 is provided in an arrangement corresponding to both the first extension base plate 7 and the second extension base plate 9 arranged around the existing base plate 2 as described later. In addition, although it is desirable that the arrangement of the rear anchor bolts 10 is as uniform as possible in the circumferential direction with the column base 1 as the center, avoidance of interference with the reinforcement of the foundation 4 and the existing building Of course, the position may be appropriately adjusted in consideration of the direction (azimuth) in which shaking is likely to occur during the earthquake.

  On the other hand, each of the first and second extension base plates 7 and 9 is previously drilled with bolt insertion holes (not shown) corresponding to the arrangement of the post-fixed anchor bolts 10 provided on the foundation 4. .

  Next, as shown in FIG. 2 (a), the first extension base plate 7 is brought closer to the column base 1 from the side, and the notches 8 are fitted outside the three sides of the existing base plate 2. Placed on the foundation 4 in the state of being. At the same time, the bolt insertion holes (not shown) of the first additional base plate 7 are fitted on the corresponding post-fixed anchor bolts 10 (see FIGS. 1A and 1B) on the upper surface of the foundation 4 at the same time. To do.

  When a brace (not shown) is connected to one side of the column base 1 or an interference such as a pipe (not shown) is arranged near one side of the lower end of the column base 1, the first The extension base plate 7 is in a state where interference with the brace and the interference is avoided if the notch 8 is fitted close to the column base 1 from the side where the brace or interference is not arranged. Can be easily arranged on the foundation 4.

  After the first extension base plate 7 is disposed on the foundation 4 as described above, the second extension base plate 9 is brought close to the column base 1 to leave the remaining side of the existing base plate 2 and the first side. Arranged on the foundation 4 so as to be along one long side of the extension base plate 7. At the same time, a bolt insertion hole (not shown) of the second extension base plate 9 is externally fitted to the corresponding post-fixed anchor bolt 10 (see FIGS. 1A and 1B) on the upper surface of the foundation 4. To do. Since the second extension base plate 9 has a rectangular shape, a brace (not shown) is connected to one side of the column base 1 or an interference such as a pipe (not shown) near one side of the lower end of the column base 1. Even when the is placed, there is no particular difficulty in placing on the foundation 4 as described above.

  Next, each of the additional base plates 7 and 9 is fixed on the foundation 4 by screwing and tightening a nut 12 to a protruding end portion of each post-fixed anchor bolt 10 protruding to the upper surface side.

  Further, the inner end portion of the notch portion 8 of the first extension base plate 7 is welded to the corresponding three sides of the existing base plate 2 over the entire length, and the notch portion 8 on one long side of the first extension base plate 7 is welded. The corresponding end sides of the second extension base plate 9 are welded over the entire length to both sides of the base plate 2 and the remaining one side of the existing base plate 2.

  Thereafter, between the side surface of the lower end portion of the column base 1 and the upper surfaces of the first and second extension base plates 7 and 9 joined around the existing base plate 2, the existing base plate 2 and the first and second A plurality of rib members 11 are arranged in the circumferential direction so as to straddle the welded portions 13 with the second extension base plates 7 and 9, and the rib members 11 are connected to the side surfaces of the lower ends of the column bases 1, It joins to the upper surface of said 1st and 2nd each extension baseplates 7 and 9, respectively by welding. Thereby, a force (load) can be transmitted between the column base 1 and the additional base plates 7 and 9 via the rib members 11.

  Furthermore, as shown by a two-dot chain line in FIGS. 1A and 1B, a welded portion 14 between each of the additional base plates 7 and 9 is provided on the upper surface of each of the first and second additional base plates 7 and 9. You may make it provide the rib member 15 arrange | positioned so that it may straddle. At this time, the rib member 15 is joined to the rib member 11 installed between the side surface of the lower end portion of the column base 1 and the first extension base plate 7 as shown in FIGS. In this case, in order to disperse and support the load, a rib member 15a for reinforcement is further provided on the surface of the rib member 11 opposite to the joint portion of the rib member 15. It is desirable.

  Thus, according to the column base reinforcement method and apparatus of the present invention, the shearing force and the pulling force generated between the column base 1 and the foundation 4 of the existing building during an earthquake or the like are more In addition to transmitting to the foundation 4 via the bolt 5, the newly installed rib members 11, the respective extension base plates 7 and 9, and the post-fixed anchor bolts 10 are connected to the foundation 4 from the lower end of the column base 1. Can be communicated and supported. Therefore, the seismic reinforcement which improves the resistance with respect to the above-mentioned shearing force and pulling-out force can be performed about the foundation installation part in the column base 1 of the said existing building.

  Furthermore, in the column base reinforcement method and apparatus of the present invention, as a base plate for expansion to be installed around the existing base plate 2, a U-shaped first extension base plate 7 having the cutout portion 8 and a rectangular second base plate are provided. Since a two-part structure having an extension base plate 9 is used, for example, each extension base plate 7, 9 in the field is compared with the case where separate extension base plates are provided on four sides of the existing base plate 2. The number of transfer operations can be reduced. Even when braces and pipes (not shown) are arranged near the lower end of the column base 1, the installation work of each extension base plate 7, 9 on the foundation 4 can improve workability. it can.

  Moreover, even if the level of the upper surface of the foundation 4 of the column base 1 to be reinforced is irregular, the extension base plates 7, 9 and the existing base plate 2, and the extension base plates 7, 9 Since the number of alignment operations between each other can be reduced, alignment can be performed more easily, and this also improves the workability.

  Further, the additional base plates 7 and 9 having the two-part structure can reduce the amount of work for performing butt welding in the field, and this can also improve the workability.

  Next, FIG. 3 shows an application example of the above embodiment as another embodiment of the present invention.

  The column base reinforcing device 6 according to the present embodiment has a configuration similar to that shown in FIGS. 1 (a) and 1 (b), but the second extension base plate 9 is replaced with a simple rectangular shape, instead of one side. The second extension base plate 9a provided with the fitting recess 16 for fitting one end edge portion of the existing base plate 2 is used in the middle portion of the base plate 2.

  As described above, the first extension base plate 7 is provided on one long side as one end edge of the existing base plate 2 is fitted into the fitting recess 16 provided in the second extension base plate 9a. The depth (depth) cut out from the one long side of the cutout portion 8 is reduced by an amount corresponding to the depth (depth) from one side of the fitting recess 16 of the second extension base plate 9a. It is.

  Other configurations are the same as those shown in FIGS. 1A and 1B, and the same components are denoted by the same reference numerals.

  According to the column base reinforcing device 6 of the present embodiment, in addition to being able to obtain the same effects as those of the above embodiment, the positioning work when installing the second additional base plate 9a on the foundation 4 is facilitated. Can be. Therefore, in this Embodiment, workability | operativity at the time of performing seismic reinforcement of the column base 1 can further be improved.

  In addition, this invention is not limited only to the said embodiment, According to the intensity | strength desired for the earthquake-proof reinforcement of the column base 1 in an existing building, the number of the back anchor bolts 10 increases / decreases suitably. May be. Further, the size and shape of each additional base plate 7, 9, 9a may be appropriately changed according to the desired number of post-fixed anchor bolts 10.

  The rib member 11 has an inclination angle and a size of the hypotenuse according to the magnitude of the load transmitted between the column base 1 and each extension base plate 7, 9, 9a, and the size of each extension base plate 7, 9, 9a. You may change the number of installation regarding the circumferential direction of the column base 1 suitably.

  The column base 1 may have any cross-sectional shape other than the H-shaped steel shown, such as a rectangular tube.

  Furthermore, the column base reinforcement method and apparatus of the present invention is an existing building having a structure in which the existing steel column base 1 is joined to the foundation 4 through the existing base plate 2 as described above. As various plants, you may apply for the seismic reinforcement of the foundation installation part of the column base 1 in production facilities, such as a waste heat recovery boiler, an LNG plant, and a power plant. Furthermore, the column base reinforcement method and apparatus of the present invention are not limited to plants, but are applied to seismic reinforcement for column bases 1 of support devices that support air conditioning equipment, food and chemical equipment, and large equipment. Of course, you may do.

  Of course, various modifications can be made without departing from the scope of the present invention.

1 Column base, 2 Existing base plate, 4 Foundation, 5 Existing anchor bolt, 7 First extension base plate, 8 Notch, 9, 9a Second extension base plate, 10 Rear anchor bolt, 11 Rib member, 16 Recess for fitting

Claims (3)

Around the existing base plate that is provided at the lower end of the steel column base of an existing building and fixed to the foundation via the existing anchor bolts, the existing base plate is in the middle of one side. A first extension base plate having a cutout portion corresponding to the planar shape of the base plate, and a plate-like second extension base plate located on the one side of the first extension base plate are attached,
And post-fixed anchor bolts for fixing each extension base plate to the foundation,
A column base reinforcement device comprising: a structure including a rib member attached between a lower end portion of the column base and each of the additional base plates. The column base reinforcing device according to claim 1, wherein a fitting recess for fitting one end edge portion of the existing base plate is provided on a side of the second extension base plate in contact with the existing base plate. Around the existing base plate that is provided at the lower end of the steel column base of an existing building and fixed to the foundation via the existing anchor bolts, the existing base plate is in the middle of one side. A first extension base plate having a cutout portion having a shape corresponding to the planar shape of the base plate, and a plate-like second extension base plate located on the one side of the first extension base plate;
Each extension base plate is fixed to the foundation via post-fixed anchor bolts, the extension base plate and the existing base plate, and the extension base plates are joined together,
Next, a rib base reinforcing method is provided, wherein a rib member is attached between a lower end portion of the column base and each of the additional base plates.

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