Patent Grant
11313144
The present disclosure relates to a seismic reinforcement, and more particularly, to a seismic reinforcement structure and a seismic retrofitting method that can be installed in a building of lightweight wooden structure or the like to improve seismic resistance.
An earthquake is a phenomenon in which the energy inside the earth comes out to the surface and the ground splits and shakes, and the shaking that occurs at this time acts as a load on the building and causes a great deal of damage to the building. For this reason, in South Korea, seismic design is mandatory in high-rise buildings with three or more floors or more than 500 m3, and laws and legislations have been strengthened that after the 2016 Gyeongju earthquake and the 2017 Pohang earthquake, seismic design is mandatory in all wood-structured houses, including a single-family house, regardless of floor or area.
Conventionally, many techniques for improving seismic resistance have been developed in order for buildings to satisfy seismic design standards. As an example, in the Korean Unexamined Patent Publication No. 10-2017-0055501, a damper was installed on the building so as to absorb vibration energy caused by an earthquake.
However, the conventional seismic resistance improvement technology as described above is applicable only when the target building is a heavy building. Seismic reinforcement structures to improve the seismic resistance is also heavy and expensive, and there was a limit to its application to lightweight wooden buildings. In addition, it has been more than 30 years since the American lightweight wooden house construction method was introduced in Korea, but there is almost no seismic reinforcement technology suitable for the characteristics of the Korean morphostructure. Accordingly, there is an urgent need to develop a seismic reinforcement structure that can be applied even to light weight wooden buildings.
(Patent Literature 1] 1. Korean Unexamined Patent Publication No. 10-2017-0055501 (“Inter-element joint structure”)
[Patent Literature 2] 2. Korean Registered Patent No. 10-1137236 (“Seismic reinforcement construction method of building using seismic reinforcing device”)
(Patent Literature 3] 3. Korean Registered Patent No. 10-1704361 (“Reinforcement method and reinforcement structure of ground equipments with reinforced seismic performance by variable bracket”)
The present disclosure has been designed to solve the above-mentioned problems, and it is an object of the present disclosure to provide a lightweight and economical seismic reinforcement structure applicable to a lightweight wooden building.
On the other hand, the object of the present disclosure is not limited to the object mentioned above, other objects that are not mentioned will be clearly understood from the following description.
The seismic reinforcement structure of a wooden structure building according to one preferred embodiment of the present disclosure includes: a first bracket including a horizontal part extending in contact with the bottom surface of the building, and a vertical part formed in connection with the horizontal part and extending in contact with the wall surface of the building; a second bracket including a horizontal part extending in contact with the ceiling of the building, and a vertical part formed in connection with the horizontal part and extending in contact with the wall surface of the building; and a connecting support rod having a vertically long shape and vertically connecting the horizontal part of the first bracket and the second bracket.
Further, each of the first bracket and the second bracket connects a horizontal portion and a vertical portion, and a curved surface portion formed with a predetermined radius of curvature is further formed.
Here, when the length in the first direction in which the horizontal parts of the first bracket and the second bracket are extended is set up to be L1, the length in the second direction in which the vertical parts are extended is set up to be L2 and the radius of curvature of the curved surface portion is set up to be R, the L2 is formed with a length of 1.5L1 or more and 4L1 or less, and the R is formed with 0.1L1 or more and 0.5L1 or less.
Further, the curved surface portion is characterized in that the width or thickness is formed to be smaller than the horizontal part or the vertical part.
Further, the connecting support rod includes: a plurality of screw rods which are formed in a vertically long shape, have a male screw formed on the outer surface, and are arranged in succession to each other in the vertical direction; and a connector which has a tubular shape, has a female screw formed on an inner peripheral surface thereof, and is screw-coupled by the screw rod arranged in succession to each other at both ends, so that the length and tension can be adjusted.
Further, the connecting support rod vertically penetrates the horizontal parts of the first bracket and the second bracket, and the ceiling of the building, so that an upper end is fixed to the ceiling and a lower end is inserted into a bottom surface of the building; and the seismic reinforcement structure is provided so as to surround a lower end of the connecting support rod at a portion where the lower end of the connecting support rod of the bottom of the building is inserted, and further includes an anchor for fixing the connecting support rod.
Alternatively, the seismic reinforcement structure further includes: an anchor composed of an insertion part having a predetermined shape and embedded in the bottom, and a protrusion extending upwardly from the insertion part and vertically protruding the first bracket to protrude upwardly from the bottom surface; and the connecting support rod vertically penetrates a horizontal part of the second bracket and a ceiling of the building, so that an upper end is fixed to the ceiling and a lower end is connected to the upper part of the protrusion portion.
Further, the building includes two or more floors, the first bracket and the second bracket being installed on each floor; and the connecting support rod is configured so that the upper end penetrates the second bracket of the uppermost floor and is fixed to the ceiling, the lower end is fixed to the anchor provided at the bottom of the lowermost floor, and the central part penetrates at least the brackets excluding the second bracket of the uppermost floor and the first bracket of the lowermost floor.
On the other hand, a seismic retrofitting method according to one preferable embodiment of the present disclosure for constructing the seismic reinforcement structure, the method comprising the steps of: 1) arranging a steel reinforcement to be included in a bottom of the building; 2) fixing an insertion part to the steel reinforcement so that the protrusion of the anchor protrudes at a position where the first bracket is installed; 3) placing concrete so that the steel reinforcement and the insertion part are embedded, thereby forming the bottom of the building; 4) forming the wall surface and the ceiling on the upper side of the bottom to construct a building; 5) inserting the protrusion into a through hole formed in the horizontal part of the first bracket, then fixing the first bracket to the bottom and the wall surface, and fixing the second bracket to the ceiling and the wall surface so as to face the first bracket; and 6) penetrating and fixing an upper end of the connecting support rod to the horizontal part of the second bracket and the ceiling, and connecting a lower end of the connecting support rod to the protrusion.
At this time, when two or more floors are included in the building, in step 4), a wall surface, a ceiling and a bottom are additionally constructed on the upper side of the bottom so as to correspond to the number of floors included in the building; in step 5), the first bracket and the second bracket are fixed at a position facing each other on each floor, but the first bracket and the second bracket included in each floor is arranged on the same line each other, and in the case of the lowermost floor, the protrusion is inserted into a through hole formed in a horizontal part of the first bracket; and in step 6), the upper end of the connecting support rod is fixed through the horizontal part of the second bracket and the ceiling of the uppermost floor, and the lower end of the connecting support rod is connected to the protrusion of the lowermost floor.
Alternatively, the method of the present disclosure includes the steps of: a) forming an anchor groove by drilling a position where the first bracket is installed at the bottom of the building; b) injecting a liquid chemical anchor into the anchor groove; c) fixing the first bracket to the bottom and the wall surface, and fixing the second bracket to the ceiling and the wall surface so as to face the first bracket; d) inserting a lower end of the connecting support rod into the anchor groove through a horizontal part of the first bracket and solidifying the chemical anchor; and e) fixing the upper end of the connecting support rod through the horizontal part of the second bracket and the ceiling.
At this time, when two or more floors are included in the building, in step a), an anchor groove is formed only at the bottom of the lowermost floor of the building, in step c), the first bracket and the second bracket are fixed to positions facing each other on each floor, but the first bracket and the second bracket included in each floor are disposed on the same line each other, and in step e), the upper end of the connecting support rod is fixed through the horizontal part of the second bracket and the ceiling on the uppermost floor.
The seismic reinforcement structure and the seismic retrofitting method of the present disclosure based on the configuration as described above are effective to support left and right vibration by supporting between the wall surface and the bottom surface or between the wall surface and the ceiling through the configuration of the bracket.
In particular, the vertical part elastically supports the wall surface with respect to the horizontal part by the shape characteristic of the curved surface portion, so that it is effective to absorb vibration in the left and right directions and improve the seismic resistance.
In addition, through the ratio of the length between the horizontal part and the vertical part, the wall surface can be effectively supported even when a large load is not applied to the horizontal part.
Moreover, by keeping a separation distance constant between the ceiling and the bottom through the structure of the connecting support rod, it is effective to disperse the load concentrated on the support and the wall surface when the vertical vibration occurs.
Further, through the configuration of the connecting support rod composed of a screw rod and a connector, the length can be adjusted and customization can be applied to the building of various heights, and it is effective to adjust the tension applied between the ceiling and the bottom.
Further, the connecting support rod is fixed to the bottom of the building via the configuration of the anchor, and the relative position of the bottom of the whole building is fixed, so that the building can be prevented from collapsing.
Preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Prior to the description, it should be understood that the terms used in the specification and the appended claims should not be construed as limited to general and dictionary meanings, but interpreted based on the meanings and concepts corresponding to technical aspects of the present disclosure on the basis of the principle that the inventor is allowed to define terms appropriately for the best explanation.
Therefore, the description proposed herein is just a preferable example for the purpose of illustrations only, not intended to limit the scope of the disclosure, so it should be understood that other equivalents and modifications could be made thereto without departing from the spirit and scope of the disclosure.
Hereinafter, the technical idea of the present disclosure will be described in more detail with reference to the accompanying figures. The accompanying figures are only examples for explaining the technical idea of the present disclosure in more detail and the technical idea of the present disclosure is not limited to the form of the accompanying figures.
[Seismic Reinforcement Structure]
As shown in
Prior to describing the configuration of each part, the structure of the building 10 to which the seismic reinforcement structure 1000 according to the preferred embodiment of the present disclosure can be applied will be briefly described. The building 10 includes a bottom 11 consisting of a first bottom layer 11a made of concrete in which a steel reinforcement is arranged inside the ground, and a second bottom layer 11b made of lightweight wood laminated on the upper side thereof; a wall surface 13 which is perpendicularly raised and installed to the bottom 11 so as to form a predetermined space on the upper side of the bottom 11; and a ceiling 15 which covers the upper part of the space surrounded by the wall surface 13 and is installed so as to make contact perpendicular to the wall surface 13.
The first bracket 101 is installed at a portion where the bottom 11 and the wall surface 13 are in contact each other, and serves to support the wall surface 13 when the wall surface 13 shakes in the left and right directions due to an earthquake or the like. The second bracket 103 is installed at a portion where the ceiling 15 and the wall surface 13 contact each other, and the second bracket 103 also serves to support the wall surface 13 when the wall surface 13 shakes in the left and right directions due to an earthquake or the like.
The first bracket 101 and the second bracket 103 are formed in the same shape each other. Therefore, in the following, the first bracket 101 and the second bracket 103 are collectively referred to as a bracket 100, and the shape will be described together with each other with reference to
The horizontal part 110 is a part in contact with the bottom surface or the ceiling of the building, and the vertical part 150 is a part in contact with the wall surface. When the extending direction of the horizontal part 110 is set up to be a first direction, and the length in the first direction of the bracket 100 is set up to be L1, the length L2 in the second direction, which is an extension direction of the vertical part 150, is formed to be 1.5L1 or more and 4L1 or less. Preferably, it is preferably formed to be 1.7L1 or more and 3.2L1 or less, more preferably 1.9L1 or more and 2.1L1 or less. The above-mentioned length ratio of the length L1 in the first direction of the bracket 100 and the length L2 in the second direction is a value considering the problem that, when the length L2 in the second direction is too long compared to the length L1 in the first direction, the load acting on the horizontal part 110 increases and thus it can be easily broken, conversely, when the length L1 in the second direction is too short, it cannot support the load applied from the wall surface, and the wall surface easily collapses when vibration in the left and right directions occurs.
In addition, the length L3 in the width direction of the bracket 100, that is, the third direction which is a direction perpendicular to the first direction and the second direction, is formed preferably in the range of 0.1L1 or more and 0.4L1 or less, preferably 0.2L1 or more and 0.3L1 or less, more preferably 0.22L1 or more and 0.25L1 or less when the length in the first direction of the bracket 100 is L1. The thickness t of the bracket 100 is formed preferably in the range of 0.1L3 or more and 0.2L3 or less, preferably 0.12L3 or more and 0.15L3 or less, and more preferably 0.13L3 or more and 0.14L3 or less.
On the other hand, the material of the bracket 100 is made of SK3 carbon tool steel. More precisely, it is preferable that the reference code in KS D3751 is STC105 (STC3) and the reference code in JIS4401 is a carbon tool steel which is SK3(SK105) grade. At this time, as the chemical composition of the bracket 100, when C nominal is 1, C (carbon) is 1.00 to 1.10, Si (silicon) is 0.10 to 0.35, Mn (manganese) is 0.10 to 0.50, P (phosphorus) is 0.03, S (sulfur) is 0.03, Cr (chromium) is 0.50 to 1.00, W (tungsten) is 0.50 to 1.00. Heat treatment at 750 to 780° C. is easy to increase impact resistance and abrasion resistance. In addition, if the rust preventive treatment is performed after the heat treatment, it is possible to prevent the occurrence of rust and corrosion.
Referring briefly to
Referring again to
When the first bracket 101 and the second bracket 103 are installed in a building, the first bracket 101 has a form in which a horizontal part 110 is extended in contact with the bottom surface of the building, the vertical part 150 is installed so as to extend in contact with the wall surface, the second bracket 103 has a form in which the horizontal part 110 is extended in contact with the ceiling, and the vertical part 150 is installed so as to extend in contact with the wall surface.
In addition, the horizontal part 110 of the first bracket 101 and the horizontal part 110 of the second bracket 103 are arranged so that they are located on the same line each other in the vertical direction when installed in the building.
In the horizontal part 110, a through-hole 111 into which a connecting support rod or an anchor described later is inserted is formed. The formation position of the through hole 111 is formed on the side where the curved surface portion 130 is formed based on the first direction, it is formed at the center of the horizontal part 110, that is, at a point of 0.5L3 based on the third direction, and the diameter of the through hole 111 is preferably formed in the range of 0.2L3 or more and 0.25L3 or less. For example, when the length L3 in the third direction of the bracket is formed to be 90 mm, the diameter of the through hole 111 is about 18 mm or more and 22.5 mm or less, most preferably 20 mm.
For reference, the first bracket 101 and the second bracket 103 are previously explained as being arranged so that each horizontal part 110 is disposed on the same line each other in the vertical direction when installed in the building, However, more precisely, it is preferable that the through hole 111 of the first bracket 101 and the through hole 111 of the second bracket 103 are arranged so as to be located on the same line each other in the vertical direction.
The horizontal part 110 and the vertical part 150 of each of the first bracket 101 and the second bracket 103 are fixed to the bottom surface, the wall surface, and the ceiling through a piece (not shown). To this end, a piece hole 120 is formed in each of the horizontal part 110 and the vertical part 150. The piece holes 120 are formed in pairs in a third direction, that is, in a width direction, and are formed in the size of 0.07L3 or more and 0.075L3 or less in diameter. For example, when L3 is 90 mm, the diameter of the piece hole 120 is 6.3 mm or more and 6.75 mm or less, preferably 6.5 mm.
In detail, the position of the piece hole 120 formed in the horizontal part 110 is a point spaced apart by a length of 0.7L1 or more and 0.9L1 or less in the first direction with respect to the side where the vertical part 150 is formed. More precisely, it is formed at a point separated by 0.8L1. When the piece hole 120 is formed too close to the curved surface portion 130, the bracket 100 does not move flexibly when vibration in the left and right directions occurs, thereby preventing the problem of reducing the seismic resistance. In doing so, the through hole 111 is formed so that the connecting support rod described later allows distribution of a load applied to the piece to be fastened to the piece hole 120.
The piece hole 120 formed in the vertical part 150 also starts at a point spaced by 0.25L2 in the second direction based on the side on which the horizontal part 110 is formed for the same reason as the piece hole 120 formed in the horizontal part 110, and the piece holes 120 are formed at intervals of 0.125L2 in the second direction, wherein the number of piece holes 120 formed in the vertical part 150 is formed in one pair or more and six pairs or less. This is a value considering that the maximum number of pieces that can be inserted into the piece hole 120 is 12 within a range not affecting the fatigue degree of the bracket 100. For reference, it goes without saying that the number of the piece holes 120 formed in the vertical part 150 is most preferably six pairs.
Referring briefly to
The connecting support rod 300 is formed in a vertically long shape as shown in
As shown in
The lower end of the connecting support rod 300 may be fixed to the bottom 11 in two ways.
First, referring to
The coupling relationship and structure of the lower end of the connecting support rod 300 when the seismic reinforcement structure according to the preferred embodiment of the present disclosure is applied to a newly built building will be described with reference to
The connecting support rod 300 and the anchor 500b are fixed to the bottom 11 through the coupling structure as described above, like a root of a tree in the event of an earthquake, thereby exhibiting the effect of not easily collapsing the building.
On the other hand, the bracket 100 and the connecting support rod 300 has a coupling relationship as described above, but can be implemented in different shapes.
Since the wall surface height of the building 10 are not all uniformly formed, the length of the connecting support rod 300 is also varied. In order to solve this problem, the connecting support rod 300 may include a plurality of screw rods 310 and at least one connector 330. The connector 330 has the same shape as the connector described above, wherein different screw rods 310 are respectively coupled to the upper part and the lower part so that they can be connected to each other one after another. That is, the entire length of the connecting support rod 300 can be adjusted via the connector 330. In a state in which the connecting support rod 300 is fixed to the ceiling and the bottom, the insertion degree of the screw rod 310 inserted into the inside of the connector 330 is adjusted, so that the effect capable of adjusting the tension applied by the connecting support rod 300 can be exerted.
When the building to which the seismic reinforcement structure according to the preferred embodiment of the present disclosure is applied has a multi-layer structure including two or more layers, the first bracket 101 and the second bracket 103 are installed on each floor as shown in
[Seismic Retrofitting Method]
Hereinafter, the seismic retrofitting method according to a first embodiment of the present disclosure will be described in detail. Since the seismic retrofitting method described below is a sequential method of forming the seismic reinforcement structure described above, configurations having the same names or reference numerals as those described above are considered to be the same.
Step 1) is to arrange a steel reinforcement to be included in a bottom 11 of the building 10. In this case, the steel reinforcements may be arranged after excavating the ground to a predetermined width, and a plurality of the steel reinforcements are arranged in a grid on a plane horizontal to the ground, but the contact points of different steel reinforcements that are crossed and met can be welded.
Step 2) is to fix an insertion part 530 to the steel reinforcement so that the protrusion 550 of the anchor 500b protrudes at a position where the first bracket 101 is installed. As shown in
Step 3) is to place concrete so that the steel reinforcement and the insertion part 530 are embedded, thereby forming a first bottom layer 11a of the building 10. Here, the first bottom layer 11a is further laminated with a second bottom layer 11b made of lightweight wood as the upper side of the first bottom layer made of concrete, and the protrusion 550 protrudes on the upper side of the bottom 11.
Step 4) is to form the wall surface 13 and the ceiling 15 on the upper side of the bottom to construct a building 10. At this time, any one portion of the wall surface is formed to erect within a predetermined radius from the protrusion 550.
Step 5) is to insert the protrusion 550 into a through hole 111 formed in the horizontal part 110 of the first bracket 101, then fixing the first bracket 101 to the bottom 11 and the wall surface 13, and fixing the second bracket 103 to the ceiling 15 and the wall surface 13 so as to face the first bracket 101. As described above, the through hole 111 formed in the second bracket 103 is positioned to be arranged on the same line in the vertical direction as the through hole 111 formed in the first bracket 101, and then fixed to the ceiling 15 and the wall surface 13.
Step 6 is to penetrate and fix an upper end of the connecting support rod 300 to the horizontal part 110 and the second bracket 103 and the ceiling 15, and connecting a lower end of the connecting support rod 300 to the protrusion 550. In a method of fixing the upper end of the connecting support rod 300 to the ceiling 15, a nut 350 can coupled and fixed to the upper end of the connecting support rod 300 protruding through the ceiling 15, and in a method of connecting the lower end of the connection support rod 300 to the protrusion 550, the connection can be made using the connector 330.
Step 7) is completed by adjusting the connector 330 and the screw rod 310 included in the connecting support rod 300 to adjust the tension and length of the connecting support rod 300.
The above-described steps describe the first embodiment when the building 10 has a single-story structure. When the building 10 has a multi-layer structure, some of the steps described above may be modified. In the following, each of the modified steps will be described.
In step 4), a wall surface, a ceiling 15 and a bottom 11 are additionally constructed on the upper side of the bottom so as to correspond to the number of floors included in the building 10. In this case, the remaining floors excluding the uppermost floor and the lowermost floor may be configured so that at the lower floor and the upper floor disposed adjacent to each other, the ceiling of the lower layer is the same surface as the bottom of the upper layer.
In step 5), the first bracket 101 and the second bracket 103 are fixed at a position facing each other on each floor, but the first bracket 101 and the second bracket 103 included in each floor is arranged on the same line each other, and in the case of the lowermost floor, the protrusion 550 is inserted into a through hole 111 formed in a horizontal part of the first bracket 101. The through-holes 111 formed in the first bracket 101 and the second bracket 103 installed in each floor are arranged on the same line in the vertical direction for insertion of the connecting support rod 300.
In step 6), the upper end of the connecting support rod 300 is fixed through the horizontal part 110 of the second bracket 103 and the ceiling 15_1 of the uppermost floor, and the lower end of the connecting support rod 300 is connected to the protrusion 550 protruded on the upper side of the bottom of the lowermost floor. For reference, when the building 10 is a multi-layer, it goes without saying that the anchor 500 is not provided for the penetration of the connecting support rod 300 at the remaining bottom excluding the lowest floor.
Hereinafter, the seismic retrofitting method according to a second embodiment of the present disclosure will be described in detail. The seismic retrofitting method according to a second embodiment of the present disclosure relates to a method for additionally constructing a seismic reinforcement structure in a built building.
Step a) is to form an anchor groove 510 by drilling a position where the first bracket 101 is installed at the bottom 11 of the building 10. The position where the first bracket 101 is installed is preferably formed within a predetermined radius from a portion where the bottom 11 and the wall surface 13 are connected to each other. In this case, the predetermined radius will be a range within the length in the first direction of the bracket 100
Step b) is to inject a liquid chemical anchor 500a into the anchor groove 510.
Step c) is to fix the first bracket 101 to the bottom and the wall surface, and fix the second bracket 103 to the ceiling 15 and the wall surface 13 so as to face the first bracket 101. At this time, the fixing of the second bracket 103 may be performed by changing the order at any time before the step e) described later.
Step d) is to insert a lower end of the connecting support rod 300 into the anchor groove 510 through a horizontal part 110 of the first bracket 101 and hardening the chemical anchor 500a. At this time, the connecting support rod 300 is connected vertically to the bottom 11.
Step e) is to fix the upper end of the connecting support rod 300 through the horizontal part 110 of the second bracket 103 and the ceiling 15. Similar to the first embodiment described above, the second embodiment can also perform the fixing by connecting a nut 350 to the upper end of the connecting support rod 300 protruding through the ceiling 15.
Step f) is completed by adjusting the screw rod 310 and the connector 330 included in the connection support rod 300 to adjust the tension and length of the connecting support rod 300.
When the second embodiment is a case where the building 10 has a multi-layer structure, some of the steps described above may be modified. In the following, each of the modified steps will be described.
In step a), an anchor groove 510 is formed only at the bottom 11_1 of the lowermost floor of the building 10.
In step c), the first bracket 101 and the second bracket 103 are fixed to positions facing each other on each floor, but the first bracket 101 and the second bracket 103 included in each floor are disposed on the same line each other in the vertical direction.
In step e), the upper end of the connecting support rod 300 is fixed through the horizontal part of the second bracket and the ceiling on the uppermost floor, and the ceiling 15 and the bottom 11 of the remaining floors excluding the ceiling 15_1 of the uppermost floor and the bottom 11_1 of the lowermost floor are coupled through the connecting support rod 300.
The technical spirit of the present disclosure should not be interpreted as being limited to the above-described embodiments. It goes without saying that the scope of application is varied, and various modifications can be made at the level of those skilled in the art without departing from the gist of the present disclosure as claimed in the claims. Therefore, such improvements and modifications fall within the protection scope of the present disclosure as long as those skilled in the art will be apparent.
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