JP2015048643A - Aseismic reinforcing method for existing building, and aseismic reinforcing structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aseismic reinforcing method for an existing building, which minimizes a deformation amount of an existing building by preventing an existing foundation from floating due to an earthquake, and prevents high axial force due to tensioning force applied to an anchor from causing an affection on the existing building.SOLUTION: New foundations 6 are provided at a required interval on at least one side face of an existing foundation 2 in an existing building 1. In the new foundation, joint bars 9 are provided in advance on a side facing the existing foundation 2 while being projected, and a ground anchor 7 extending into and anchored in a bearing ground is provided. After the ground anchor 7 is tension-anchored, the ground anchor 7 is provided in the existing foundation 2 and/or a column 5 within a required interval, and thereafter construction anchor bars 8 and the joint bars 9 of the new foundation 6 are connected together as reinforcing-bar lap joints. Concrete 10 is placed within the required interval and/or on the upper part of the existing foundation 2 to integrate the new foundation 6 with the existing foundation 2, and/or the column 5.

Description

  The present invention relates to a seismic reinforcement method for an existing building and a seismic reinforcement structure obtained by the reinforcement method, for example, for measures against earthquakes and strong winds.

  In a method and a structure for reinforcing an existing foundation in this type of existing building, for example, a plurality of techniques are known. The first conventional example according to the public knowledge is a reinforcing structure of an existing building, and is a ground improvement portion constructed by improving the ground of at least a part of the ground below the existing building, and one end is anchored to an anchor. A reinforcing structure for an existing building, comprising an anchor fixed to the ground and having an anchor fixed to the structure of the existing building in a state in which tension is applied to the other end or in a state where tension is not applied (Patent Document 1).

  And in the above reinforcing structure, even if the existing building is built on the soft ground by improving the soft ground below the existing building, or even if the foundation pile of the existing building does not have sufficient proof stress The tension can be applied to the anchor. As a result, the existing building can be anchored to the anchor anchorage ground by the anchor, and seismic reinforcement can be performed even in the case where the building is crowded around without providing a new frame outside. It is said.

  The second conventional example is the same applicant as the first conventional example, and the seismic reinforcement is performed by fixing the anchor to the structure constructed on the ground and the anchoring ground of the anchor. In the method, the tension material of the anchor is applied with a tension force that is large enough to prevent the tension material from loosening and a tension force that is smaller than the design tension force at the time of the occurrence of the earthquake. An earthquake-proof reinforcing method characterized in that anchors are fixed to the structure and the fixing ground (Patent Document 2).

  According to this seismic reinforcement method, the construction cost can be reduced, the construction period can be shortened, and the seismic performance of the structure built on the ground can be improved.

JP 2008-223430 A JP2012-127119A

  In the first conventional example, the anchor is directly fixed to the existing foundation, and there are two cases where the tension is applied to the anchor and when the tension is not applied. First, when a tension force is applied, the tension force is added to the existing foundation as a stress such as an axial force and has a great influence, and the existing foundation cannot withstand the extra stress. Therefore, the ground improvement of the said ground was required, construction cost increased, and the construction period was prolonged. When tension is not applied, there is no tension that can be canceled with respect to the pull-out force caused by the shaking of the earthquake, so the amount of extension of the unpound PC steel material at the anchor free length is large, and the seismic performance is reduced. There is a problem that the deformation amount (interlayer deformation angle) becomes large.

  Also in the second prior art, the structure constructed on the ground is a structure in which a new foundation is integrated with an existing foundation, and after the integration, an anchor is installed on the new foundation, In order to give the tension of a magnitude that does not sag, the amount of elongation of the PC steel material is greatly increased by the pulling force due to the shaking of the earthquake, as in the first conventional technique, so the deformation amount of the existing building increases. It has the problem that it ends up.

  Therefore, in the conventional technology related to the seismic reinforcement of existing buildings, the existing foundation has a high axial force due to the tension applied to the anchor, and the existing building is prevented from being lifted by the pulling force due to the earthquake, and the deformation amount of the existing building is kept small. It has a solution to avoid affecting the foundation.

  As a specific means for solving the problems of the above-described conventional example, the first invention according to the present invention provides a new foundation with a required interval on at least one side of the existing foundation in the existing building, and the new foundation A joint bar is provided in advance so as to protrude on the side facing the foundation, and a ground anchor is provided to extend and be fixed in the support ground. After the ground anchor is tension-fixed, the existing foundation and / or within the required interval are provided. Alternatively, the post-construction anchor bar provided on the column and the joint bar of the new foundation are joined together, and concrete is placed within the required interval and / or above the existing foundation, and the new foundation, the existing foundation and / or the column The present invention provides a seismic reinforcement method for an existing building, which is characterized by integrating the two.

  According to a second aspect of the present invention, a new foundation is provided by providing joints on both sides of an existing foundation in an existing building, a ground anchor that extends into the supporting ground and is fixed to the new foundation, and the ground anchor is tensioned. After fixing, after filling the joint with the filler and hardening, PC steel material is inserted into the through hole provided in the existing foundation and the through hole provided in the new foundation beforehand, and the tension is fixed to the new foundation on both sides. It provides a seismic reinforcement method for existing buildings, which is characterized by integrating a new foundation and an existing foundation.

  According to a third aspect of the present invention, a new foundation is provided by providing a required interval on both sides of an existing foundation in an existing building, and a joint bar is provided in advance on the side facing the existing foundation. In addition, a ground anchor that extends into the supporting ground and is fixed is provided, and after fixing the ground anchor in tension, the post-construction anchor bar provided on the existing foundation and the joint bar of the new foundation are connected within the required interval. In addition, concrete is cast and PC steel is inserted into the through-hole already provided in the existing foundation and the through-hole provided in the new foundation, and the new foundation and the existing foundation are integrated with the new foundation on both sides. It is intended to provide a seismic reinforcement method for existing buildings.

  According to a fourth aspect of the present invention, a notch portion is formed at an upper portion of at least one side surface of an existing foundation in an existing building, a new foundation is provided by providing a joint portion, and the new foundation is fixed by extending into the supporting ground. A ground anchor to be provided is provided, and a joint bar projecting to the notch portion is provided, and after fixing the ground anchor in tension, a filler is filled in the joint portion and concrete is placed in the notch portion to cotter The new foundation and the existing foundation are integrated and / or PC steel is inserted into the through-hole already provided in the existing foundation and the through-hole provided in the new foundation, and the tension is fixed on the new foundation on both sides. It provides a seismic reinforcement method for existing buildings, which is characterized by integrating a new foundation and an existing foundation.

  According to a fifth aspect of the present invention, a joint base is provided on at least one side surface of an existing foundation in an existing building to provide a new foundation, and a joint bar is provided in advance on the new foundation so as to protrude above the existing foundation. In addition, when a ground anchor is provided that extends into the supporting ground and is fixed, and after fixing the ground anchor to tension, the joint is filled with a filler and cured, and then a new foundation is provided on both sides. A seismic reinforcement method for an existing building, characterized in that an additional joint bar is placed between the joint bars of the existing joint, the joint bars are joined together, and concrete is placed on the upper part of the existing foundation to integrally form a cotter. It is to provide.

  According to a sixth aspect of the present invention, a notched portion is formed at the upper part of two side surfaces of an existing foundation in an existing building, and a new foundation is provided at a necessary interval, and the new foundation is on the side facing the existing foundation. And a side corresponding to the notch is provided in advance so as to project a joining bar, and a ground anchor is provided to be extended and fixed in the supporting ground. Post-installed anchor bars provided in the foundation and notch and the joint bars of the new foundation are joined together to place the concrete and / or integrated into the existing foundation and through holes provided in the existing foundation. The present invention provides a method for seismic reinforcement of an existing building, in which a PC steel material is inserted into the through-hole and tension is fixed on the new foundation on both sides to integrate the new foundation and the existing foundation.

  According to a seventh aspect of the present invention, a new foundation is provided with a required interval on two sides of an existing foundation in an existing building, and a joint bar is projected in advance on the side facing the existing foundation and the column. And a ground anchor for extending and fixing in the supporting ground, and after fixing the ground anchor in tension, the post-installed anchor bar and the newly installed foundation provided on the existing foundation and the pillar within the required interval And / or if a new foundation is provided on both sides, an additional joint is placed between the joints on both sides, and the joint is joined to the upper part of the existing foundation. A seismic reinforcement method for an existing building is provided, in which a cotter is integrally formed by placing a cotter.

  According to an eighth aspect of the present invention, a new foundation is provided by providing a joint on at least one side surface of an existing foundation in an existing building, and a joint bar is provided in advance on the new foundation so as to protrude above the existing foundation. And a ground anchor for extending and fixing in the supporting ground, and after fixing the ground anchor in tension, after filling and hardening the filler in the joint, the post-installed anchor bar and the new foundation A seismic reinforcement method for an existing building is provided, in which concrete joints are formed by connecting concrete joints to the upper part of the existing foundation and casting concrete on top of the existing foundation.

  According to a ninth aspect of the present invention, there is provided a seismic reinforcement structure for an existing building obtained by the seismic reinforcement method according to any one of the first to eighth aspects.

  According to the first to ninth inventions, the new foundation is tension-fixed to the supporting ground by the ground anchor, and then the new foundation and the existing foundation or the cotter are integrated, thereby increasing the height of the ground anchor. The axial force does not affect the existing foundation, and the new foundation or the cotter integrated with the new foundation suppresses the pulling force of the existing foundation in the event of an earthquake to reinforce the overall strength of the existing foundation, and the pulling force in the event of an earthquake. It has an excellent effect of preventing the building from falling over.

  In addition, a number of seismic reinforcement methods were provided for existing foundations, and various existing buildings and existing foundations could be reinforced by freely combining any of these methods and methods.

BRIEF DESCRIPTION OF THE DRAWINGS The earthquake-proof reinforcement structure of the existing building which concerns on the 1st Embodiment of this invention is shown schematically, (a) is a top view which shows an example of a corner foundation, (b) is the same side view. The 1st Embodiment is similarly shown, (c) is a top view which shows the other example of a corner base, (d) is the same side view. The 1st Embodiment is similarly shown, (e) is a top view which shows the foundation of an outer peripheral side surface, (f) is the same side view. BRIEF DESCRIPTION OF THE DRAWINGS The earthquake-proof reinforcement structure of the existing building which concerns on the 2nd Embodiment of this invention is shown schematically, (a) is a top view which shows an example of a corner foundation, (b) is the same side view. 2nd Embodiment is shown similarly, (c) is a top view which shows the other example of a corner base, (d) is the same side view. Similarly, the second embodiment is shown, in which (e) is a plan view showing the basis of the outer peripheral side surface, and (f) is a side view thereof. It shows schematically the earthquake-proof reinforcement structure of the existing building which concerns on the 3rd Embodiment of this invention, (a) is a top view which shows a corner foundation, (b) is the same side view, (c) is It is a top view which shows the foundation of an outer peripheral side surface. It shows schematically the earthquake-proof reinforcement structure of the existing building concerning the 4th embodiment of the present invention, (a) is a top view showing a corner foundation, (b) is the same side view, (c) is It is a top view which shows the foundation of an outer peripheral side surface. The earthquake-proof reinforcement structure of the existing building which concerns on the 5th Embodiment of this invention is shown schematically, (a) is a top view which shows an example of a corner | foundation foundation, (b) is the same side view. FIG. 5C also shows the fifth embodiment, in which (c) is a plan view showing an example of the foundation of the outer peripheral side surface, (d) is a plan view showing another example of the foundation of the outer peripheral side surface, and (e) is the same side surface. FIG. The earthquake-proof reinforcement structure of the existing building which concerns on the 6th Embodiment of this invention is shown roughly, (a) is a top view which shows an example of a corner | foundation foundation, (b) is the same side view. Similarly, FIG. 6 shows the sixth embodiment, (c) is a plan view showing an example of the foundation of the outer peripheral side surface, (d) is a plan view showing another example of the foundation of the outer peripheral side surface, and (e) is the same side surface. FIG. It shows schematically the earthquake-proof reinforcement structure of the existing building which concerns on the 7th Embodiment of this invention, (a) is a top view which shows a corner foundation, (b) is the same side view, (c) is It is a top view which shows the foundation of an outer peripheral side surface. It shows schematically the earthquake-proof reinforcement structure of the existing building which concerns on the 8th Embodiment of this invention, (a) is a top view which shows a corner foundation, (b) is the same side view, (c) is It is a top view which shows the foundation of an outer peripheral side surface. The earthquake-proof reinforcement structure of the existing building which concerns on the 9th Embodiment of this invention is shown roughly, (a) is a top view which shows a corner | foundation foundation, (b) is the same side view. Similarly, the ninth embodiment is shown, in which (c) is a plan view showing the basis of the outer peripheral side surface, and (d) is a side view thereof. The earthquake-proof reinforcement structure of the existing building which concerns on the 10th Embodiment of this invention is shown roughly, (a) is a top view which shows a corner | foundation foundation, (b) is the same side view. Similarly, the tenth embodiment is shown, in which (c) is a plan view showing the basis of the outer peripheral side surface, and (d) is a side view thereof. It shows schematically the earthquake-proof reinforcement structure of the existing building which concerns on the 11th Embodiment of this invention, (a) is a top view which shows a corner foundation, (b) is the same side view, (c) is It is a top view which shows the foundation of an outer peripheral side surface. It shows schematically the earthquake-proof reinforcement structure of the existing building concerning the 12th embodiment of the present invention, (a) is a top view showing a corner foundation, (b) is the same side view, (c) is It is a top view which shows the foundation of an outer peripheral side surface. The earthquake-resistant reinforcement structure of the existing building which concerns on the 13th Embodiment of this invention is shown schematically, (a) is a top view which shows a corner | foundation foundation, (b) is the same side view.

  The present invention will be described in detail based on a plurality of illustrated embodiments. Although not shown in the drawings, existing buildings of low-rise or middle-high rise are constructed by building pillars on various existing concrete foundations and integrally forming walls and the like. In such a building, when a horizontal force due to an earthquake acts on the building, a bending moment is generated in the plane (cross section), and the tensile force (withdrawal force) due to the bending moment is such that the central part of the building is small and the outer peripheral part is large. Is a well-known fact in this kind of technical field, and in particular, the pulling force acting on the outer column located on the outer circumference and the corner column located on the corner is different, and the existing foundation on the outer circumference supporting them is different. Naturally, the pulling force acting on the existing foundation at the corner is also different.

  Therefore, in the first embodiment shown in FIGS. 1-1 to 3 (a) to (f), the existing building 1 is constructed by, for example, driving the existing foundation 2 (also called existing footing) into the ground. It is formed integrally with the upper part of the existing pile foundation 3 and is formed in a state where the adjacent beams are connected by the underground beam 4. The upper part of the existing foundation 2 is flat, and a column is formed in the flat central part. 5 is built in a low-rise or middle-high building.

  In such an existing building 1, the case where the existing foundation 2 at the corners shown in FIGS. As for the existing foundation 2 in the corner, the two side surfaces are partially vacant by the building 1 as viewed from above, but the other two side surfaces are completely vacant. Therefore, as an example, as shown in FIGS. (A) and (b), a new foundation 6 is provided at a required interval on at least one side surface that is completely open. The new foundation 6 is formed at a position covered with the ground level GL, that is, at a height (size) below the ground level GL, and is tensioned by a ground anchor 7 that extends and settles in a supporting ground under the soft ground. It fixes and stabilizes the new foundation 6 against the pulling force caused by an earthquake or the like.

  Prior to providing the new foundation 6, the opposing surface of the existing foundation 2 is roughened, and a plurality of post-construction anchor bars 8 are provided so as to protrude. The new foundation 6 has a plurality of joint bars 9 on the opposing surface. After the new foundation 6 is tensioned and fixed by the ground anchor 7, the joint reinforcement 9 and the post-construction anchor reinforcement 8 are overlapped within the required interval between the new foundation 6 and the existing foundation 2. As a result, the newly-founded foundation 6 and the existing foundation 2 are integrated by placing the post-cast concrete 10 within the required interval. Even if it integrates in this way, since the new foundation 6 is tension-fixed by the ground anchor 7 before being integrated, the high axial force by the ground anchor 7 does not affect the existing foundation 2 and the anchor force causes an earthquake. In contrast, the overall strength of the existing foundation was reinforced against the pulling force.

  As another example, as shown in FIGS. 1-2 (c) and (d), in the existing foundation 2 at the corner, the newly installed foundation 6 is spaced apart from each of two vacant side surfaces by a required interval. Can be provided. Since the configuration and construction method of each new foundation 6 in this case are the same as described above, the same reference numerals are assigned and details are omitted because they are duplicated. In short, by providing the new foundation 6 on two vacant side surfaces, it is possible to reinforce the pulling force caused by the earthquake from two directions.

  Next, the case where the existing foundation 2 on the outer peripheral side surface supporting the outer pillar is seismically reinforced will be described. As shown in FIGS. 1-3 (e) and (f), the existing foundation 2 on the outer peripheral side has only one side that is completely open when viewed from the top, and the two sides depend on the building 1. Only about half are free. Therefore, one new foundation 6 is provided at least on the side of the existing foundation 2 that is completely open. Also in this case, as in the above-described embodiment, the post-construction anchor bar 8 protrudes from the existing foundation 2, the new foundation 6 is provided at a predetermined interval from the existing foundation 2, and the ground anchor 7 is provided on the new foundation 6. In addition to fixing the tension on the supporting ground, a plurality of joint bars 9 are provided to protrude on the surface facing the existing foundation 2, and the joint bars 9 and the post-construction anchor bars 8 are connected within a required interval. The post-cast concrete 10 is placed within the interval, and the new foundation 6 and the existing foundation 2 are integrated.

  Furthermore, if necessary, a similar new foundation 6 can be provided on each of two side surfaces where about half of the existing foundation 2 is vacant. This is because the existing foundation 2 installed on the side away from the central part of the building is considered to have a strong pulling force due to the earthquake, so the existing foundation 2 installed at a position away from the central part is resistant to extraction. In order to reinforce the force, a plurality of new foundations 6 are provided using the vacant portions, and the building is prevented from falling due to the rising of the existing foundation 2. A filler 11 is filled between the new foundation 6 and the underground beam 4. In the following embodiments, the description with the new foundation 6 is a height below the ground level GL.

  Next, the seismic reinforcement according to the second embodiment shown in FIGS. 2-1 to 3 (a) to (f) will be described. Also in this embodiment, with respect to the existing building 1 and other configurations, the same parts as those described in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. First, as an example, when the existing foundation 2 at the corner shown in FIGS. 2-1 (a) to (b) is seismically reinforced, it is newly installed at a required interval on at least one side surface that is completely open. A foundation 16 is provided. The new foundation 16 is formed higher than the existing foundation 2 (some existing foundations may be formed to protrude upward from the ground level GL) and extend into the supporting ground under the soft ground. The tension is fixed by the ground anchor 7.

  The opposing surfaces of the existing foundation 2 and the column 5 on which the new foundation 16 is provided are roughened, and a plurality of post-installed anchor bars 8 are provided to protrude on each surface, and the new foundation 16 has a plurality of joints on the opposing surfaces. The lines 9 and 19 are provided so as to protrude. In this case, the upper joint bar 19 is provided long and narrow in accordance with the position and width of the column 5. Then, after fixing the new foundation 16 with the ground anchor 7, the joining bars 9, 19 and the post-construction anchor bars 8 are joined within the required interval between the new foundation 6, the existing foundation 2 and the column 5. By placing the post-cast concrete 20 within the required interval, a cotter 20a in which a part of the post-cast concrete 20 covers the upper surface of the existing foundation 2 is formed. By the cotter 20a, the existing foundation 2 and the column 5 are The new foundation 16, the existing foundation 2, and the pillar 5 are integrated with the function of pressing down. Even if it integrates in this way, since the new foundation 16 is tension-fixed by the ground anchor 7 before integration, the high axial force by the ground anchor 7 does not affect the existing foundation 2, and the anchor force causes an earthquake or the like. It was against the pulling force and reinforced the overall strength of the existing foundation.

  As another example, as shown in FIGS. 2-2 (c) and (d), in the existing foundation 2 at the corner, the new foundation 16 is placed on each of two vacant side surfaces with a required interval. Can be provided. Since the configuration and construction method of each new foundation 16 in this case are the same as described above, the same reference numerals are assigned and details are omitted because they are duplicated. However, the width of the cotter 20a to be formed is slightly different depending on the width of the pillar 5. Then, by providing the new foundation 16 on two vacant side surfaces, the seismic reinforcement is excellent in strength against the pulling force due to the earthquake from two directions.

  Next, the case where the existing foundation 2 on the outer peripheral side surface supporting the outer pillar is seismically reinforced will be described. As shown in FIGS. 2-3 (e) and (f), the existing foundation 2 on the outer peripheral side has only one side that is completely open when viewed from the top, and the two sides depend on the building 1. Only about half are free. Therefore, one new foundation 16 is provided on the side surface of the existing foundation 2 that is at least entirely open. Also in this case, as in the above-described embodiment, the post-construction anchor bars 8 are provided so as to protrude from the existing foundation 2 and the column 5, and a new foundation 16 is provided at a necessary interval from the existing foundation 2. The ground anchor 7 fixes the tension to the supporting ground, and a plurality of joint muscles 9 and 19 are provided to protrude on the surface facing the existing foundation 2, and the joint muscles 9 and 19 and the post-construction anchor muscle 8 are within a required interval. Are joined together as a lap joint, and the post-cast concrete 20 is placed within the required interval to form a cotter 20a in which a part of the post-cast concrete 20 covers the upper surface of the existing foundation 2, and the cotter 20a The new foundation 16, the existing foundation 2 and the pillar 5 are integrated with a function of pressing the existing foundation 2 and the pillar 5. This seismic reinforcement structure is limited to the existing foundation 2 positioned in the middle part of the building 1.

  Furthermore, in the existing foundation 2 that is far from the center of the building 1, the seismic reinforcement structure is formed by combining the new foundation 6 and the new foundation 16 described in the first embodiment. That is, in the case of constructing the new foundation 6 on one side that is half vacant in the direction away from the center, and in the existing foundation 2 that supports the column located near the corner pillar, The case of constructing the new foundation 6 is considered, and the strength of the seismic reinforcement is improved by doing in this way. Depending on the structure of the building 1, a new foundation 16 with a cotter 20 a is provided on the side of the existing foundation 2 that is completely vacant from the beginning, and a new foundation 6 that has no cotter is provided on each side of the half vacant side. You may make it build. In addition, the description with the newly installed foundation 16 in the following embodiments includes the height projected above the ground level GL.

  The seismic reinforcement structure according to the third embodiment shown in FIGS. 3 (a) to 3 (c) will be described. Also in this embodiment, with respect to the existing building 1 and other configurations, the same parts as those described in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. A plurality of insertion holes 12 for PC steel, which will be described later, in the horizontal direction along one vacant side surface of the existing foundation 2 located in the corner of the existing building 1 and the vacant side surface of the existing foundation 2 on the outer peripheral side surface. Are provided in advance and adjacent to both side surfaces where the insertion holes 12 are opened, respectively, and the new foundation 6 is provided, and when the new foundation 6 is constructed, An insertion hole 12a is provided by arranging a sheath or the like.

Then, joints are provided between the new foundation 6, the existing foundation 2, and the underground beam 4 and filled with the filler 11, respectively. After the new foundation 6 is tension-fixed to the supporting ground by the ground anchor 7, the PC steel rod 13 which is a PC steel material is inserted from the insertion hole 12a of one new foundation 6 into the insertion hole 12 of the existing foundation 2, and the other new installation The existing foundation 2 and the two new foundations 6 are integrated with each other by inserting the end of the PC steel bar 13 at the end face of the other new foundation 6 by tightening the nut with a tension jack. Join to shear transfer state.
The new foundation 6 in this case is optimally precast concrete, but may be cast in place. The PC steel material may be a PC steel wire, a PC steel wire instead of the PC steel rod 13, or a high strength steel rod. Furthermore, it is good also as unpound by using unpound PC steel materials, without inject | pouring PC grout into the clearance gap between the PC steel rod 13 and the insertion holes 12 and 12a.

  Next, a fourth embodiment shown in FIGS. 4A to 4C will be described. The seismic reinforcement structure according to this embodiment uses the seismic reinforcement structure according to the first embodiment as it is to further increase the strength. The structure of the new foundation 6 is assigned the same reference numeral. The details are omitted. That is, when the new foundation 6 is constructed by previously drilling a plurality of insertion holes 12 in the corners and side surfaces of the existing foundation 2 in the same manner as in the third embodiment, the foundations 2 communicate with the insertion holes 12. The insertion hole 12a is provided at the position where the sheath is disposed.

  Then, after the new foundation 6 is tensioned and fixed on the supporting ground by the anchor 7, the joining bar 9 and the post-construction anchor bar 8 are joined together as a lap joint within the required interval between the new foundation 6 and the existing foundation 2. Then, the post-cast concrete 10 is placed within the required interval, the new foundation 6 and the existing foundation 2 are integrated, and after the post-cast concrete 10 is hardened, the PC steel bars 13 which are PC steel materials are inserted through the respective inserts. Through the holes 12, 12a, one new foundation 6 is inserted into the other new foundation 6 through the existing foundation 2, and the end of the PC steel rod 13 is tightened with a tension jack at the end face of the other new foundation 6. The existing foundation 2 and both new foundations 6 are integrally joined in a shearing transmission state by tightening.

  A fifth embodiment shown in FIGS. 5-1 to 2 (a) to (e) will be described. Also in this embodiment, the same reference numerals are given to portions common to the respective embodiments, and the details are omitted. First, the existing base 2 at the corner shown in FIGS. 5-1 (a) and (b) is provided with required (substantially L-shaped) notch portions 14 on two vacant side surfaces, respectively. At the position facing the portion 14, the new foundation 6 is provided adjacent to the existing foundation 2, and when the new foundation 6 is constructed, a plurality of joint bars 9 extending to the notch portion 14 are formed to protrude. . Then, after the new foundation 6 is tension-fixed to the supporting ground by the ground anchor 7, the post-cast concrete 10 is placed in the notch 14 to integrate the new foundation 6 and the existing foundation 2, so that In short, since the concrete 10 becomes a cotter portion for holding the existing foundation 2, the concrete 10 is integrated in a shear transmission state. The gap between the newly established foundation 6 and the existing foundation 2 is filled with the filler 11.

  In the existing foundation 2 on the outer peripheral side surface supporting the outer pillar shown in FIGS. 5-2 (c) to (e), as shown in FIG. 5 (c) as an example, one new foundation 6 is provided on one vacant side surface. As another example, as shown in (d) and (e), there are a case where the new foundation 6 is constructed on both side surfaces that are vacant. In any case, a necessary notch portion 14 is provided in advance on the existing foundation 2 on the side where the new foundation 6 is provided, and a plurality of joint bars 9 extending to the notch portion 14 are formed on the new foundation 6 so as to protrude. In addition, it is the same in that the new foundation 6 and the existing foundation 2 are integrated by placing the post-cast concrete 10 and that the post-cast concrete 10 becomes a cotter part. In addition, when providing one new foundation 6, it is limited to the existing foundation 2 located in the intermediate part of the building 1, and when providing the new foundation 6 on the side surface of both sides, it is the existing foundation 2 of the other place.

  A sixth embodiment shown in FIGS. 6-1 to 2 (a) to (e) will be described. Also in this embodiment, the same reference numerals are given to portions common to the respective embodiments, and the details are omitted. First, the existing foundation 2 at the corner shown in FIGS. 6-1 (a) and (b) is provided with a new foundation 16 that protrudes higher than the existing foundation 2 adjacent to two vacant side surfaces. When constructing these new foundations 16, a plurality of joint bars 9 extending to the vicinity of the position of the pillar 5 on the upper surface of the existing foundation 2 are formed to project. Then, after the new foundation 16 is tensioned and fixed to the supporting ground by the ground anchor 7, the post-cast concrete 10 is placed in the space between the upper surface of the existing foundation 2 and the pillar 5 to connect the new foundation 16 and the existing foundation 2. Since they are integrated, the post-cast concrete 10 becomes a cotter part that holds the existing foundation 2 and is integrated in a shear transmission state. The gaps between the new foundation 16 and the existing foundation 2 are filled with the filler 11 respectively.

  Moreover, in the existing foundation 2 of the outer peripheral side surface which supports the outer pillar shown to FIGS. 6-2 (c)-(e), as shown in (c) as an example, one new installation is carried out to one side which is vacant. There are a case where the foundation 16 is provided and another example where the new foundation 16 is constructed on both side surfaces which are vacant as shown in (d) and (e). In any case, a new foundation 16 that protrudes higher than the existing foundation 2 is provided, and a plurality of joint bars 9 extending to the vicinity of the position of the pillar 5 on the upper surface of the existing foundation 2 are formed on the new foundation 16. Are the same. Then, an additional joint bar 9a is interposed between the joint bars 9 of the new foundation 16 provided on the side surfaces on both sides, and the joint bars 9 of the new foundation 16 on both sides are connected by reinforcing bar joints. Further, after the new foundation 16 is tensioned and fixed to the supporting ground by the ground anchor 7, the space between the upper surface of the existing foundation 2 and the pillar 5 and the space of the upper surface of the existing foundation 2 between the new foundations 16 on both sides are rearranged. The same is true in that the cast concrete 10 is cast to integrate the new foundation 6 and the existing foundation 2 so that the post-cast concrete 10 becomes a cotter part. In the case where one new foundation 16 is provided, although it depends on the structure of the building 1, it is limited to the existing foundation 2 located in the middle part of the building 1; It is the existing foundation 2 of the place.

  A seventh embodiment shown in FIGS. 7A to 7C will be described. In this example, the third embodiment and a part of the fifth embodiment are combined, and parts common to these examples are denoted by the same reference numerals and details thereof are omitted. To do. That is, for the PC steel rod 13 which is a PC steel material in the horizontal direction along one vacant side surface of the existing foundation 2 located at the corner of the existing building 1 and the vacant side surface of the existing foundation 2 on the outer peripheral side surface. A plurality of insertion holes 12 are preliminarily drilled, and new foundations 6 are provided adjacent to both side surfaces where the insertion holes 12 are opened, and the existing foundation 2 on the side where the new foundation 6 is provided is provided in advance. When providing the required notch part 14 and constructing the new foundation 6, a plurality of joint bars 9 extending to the notch part 14 are formed to protrude, and at a position communicating with the insertion hole 12, The insertion hole 12a is provided by arranging a sheath or the like.

  Then, after the new foundation 6 is tensioned and fixed on the supporting ground by the ground anchor 7, the post-cast concrete 10 serving as a cotter part is cast to integrate the new foundation 6 and the existing foundation 2, and the post-cast concrete 10 is After hardening, the PC steel rod 13 which is a PC steel material is inserted from the insertion hole 12a of one new foundation 6 into the insertion hole 12 of the existing foundation 2, and is inserted into the insertion hole 12a of the other new foundation 6, and the other At the end face of the new foundation 6, the nut of the end of the PC steel bar 13 is tightened with a tension jack so that the existing foundation 2 and the two new foundations 6 are joined together, and the cotter part of the post-cast concrete 10 and the PC steel material And a shear transmission state. Further, a filler 11 is filled between the new foundation 6 and the existing foundation 2 and the underground beam 4.

  The eighth embodiment shown in FIGS. 8A to 8C will be described. In this example, the third embodiment and a part of the sixth embodiment are combined, and parts common to these examples are denoted by the same reference numerals, and details thereof are omitted. To do. That is, for the PC steel rod 13 which is a PC steel material in the horizontal direction along one vacant side surface of the existing foundation 2 located at the corner of the existing building 1 and the vacant side surface of the existing foundation 2 on the outer peripheral side surface. The plurality of insertion holes 12 are preliminarily drilled, and new foundations 16 are provided adjacent to both side surfaces where the insertion holes 12 are opened. When these new foundations 16 are constructed, A plurality of joining bars 9 extending to the vicinity of the position of the column 5 are formed so as to protrude, and a sheath or the like is provided at a position communicating with the insertion hole 12 to provide an insertion hole 12a.

  Further, an additional joint bar 9a is interposed between the joint bars 9 of the new foundation 16 provided on the side surfaces on both sides, and the joint bars 9 of the new foundation 16 on both sides are connected by reinforcing bar joints. Then, after the new foundation 16 is tensioned and fixed on the supporting ground by the ground anchor 7, the space between the upper surface of the existing foundation 2 and the pillar 5 and the space on the upper surface of the existing foundation 2 between the new foundations 16 on both sides are rearranged. The cast-in concrete 10 is cast and the new foundation 16 and the existing foundation 2 are integrated, and the post-cast concrete 10 becomes a cotter part.

  After the post-cast concrete 10 serving as the cotter portion is hardened, a PC steel rod 13 which is a PC steel material is inserted from the insertion hole 12a of one new foundation 16 into the insertion hole 12 of the existing foundation 2, and the other new foundation 16 is inserted. The end of the PC steel rod 13 is inserted into the hole 12a and the end of the other new foundation 16 is tightened with a nut with a tension jack to integrally join the existing foundation 2 and the two new foundations 16 A shear transmission state is established between the cotter portion of the cast concrete 10 and the PC steel material. Further, the filler 11 is filled between the new foundation 16 and the existing foundation 2 and the underground beam 4.

  The ninth embodiment shown in FIGS. 9-1 and 2 (a) to (d) will be described. In this example, the first embodiment and the fifth embodiment are combined, and the same reference numerals are given to the parts common to these examples, and the details are omitted. That is, the existing foundation 2 at the corner shown in FIGS. 9-1 (a) and (b) is provided with required (substantially L-shaped) notch portions 14 on two vacant side surfaces, respectively, A plurality of post-installed anchor bars 8 are provided on each of the notch portion 14 and the side surface, and a new foundation 6 is provided at a position facing the side surface with a predetermined interval from the existing foundation 2. A plurality of joint bars 9 extending within a required interval and up to the notch portion 14 are formed to protrude.

  Then, after the new foundation 6 is tension-fixed to the supporting ground with the ground anchor 7, each post-construction anchor bar 8 and the joint bar 9 are joined together as a steel lap joint, and are placed in the required interval and in the notch 14. Since the new foundation 6 and the existing foundation 2 are integrated by placing the concrete 10, the post-cast concrete 10 placed in the notch 14 becomes a cotter 10 a that holds the existing foundation 2, so that shear transmission is performed. It is integrated in a state.

  In the existing foundation 2 on the outer peripheral side surface that supports the outer pillar shown in FIGS. 9-2 (c) and (d), an example is shown in which a new foundation 6 is constructed with a required interval on both side surfaces that are vacant. It is a thing. The existing foundation 2 on the side where the new foundation 6 is provided is provided with the required notches 14 in advance, and a plurality of post-installed anchor bars 8 are provided on each of the notches 14 and the side surfaces. A plurality of joint bars 9 extending into the interval and extending to the notch portion 14 are formed to protrude, and after the new foundation 6 is tensioned and fixed to the support ground by the ground anchor 7, each post-construction anchor bar 8 and the joint bar 9 are joined together as a reinforced lap joint, and post-cast concrete 10 is cast in the required interval and notch 14 to integrate the new foundation 6 and the existing foundation 2, and the post-cast concrete 10 is a cotter part. It is the same in that. In addition, one new foundation may be provided on one vacant side surface.

  A tenth embodiment shown in FIGS. 10-1 to 2 (a) to (d) will be described. In this example, a part of the second embodiment is used, and parts common to the example are given the same reference numerals and their details are omitted. That is, in the existing foundation 2 in the corner shown in FIGS. 10-1 (a) and (b), a new foundation 16 is provided on each of two vacant side surfaces with a required interval, and the new foundation 16 is grounded. After fixing the tension to the supporting ground with the anchor 7, the post-construction anchor bar 8 and the joint bar 9 are joined together, and the post-cast concrete 20 is placed within the required interval and the upper surface of the existing foundation 2. And the existing foundation 2 and the pillar 5 are integrated, and the cotter 20a is formed on the upper part of the existing foundation 2.

  In the existing foundation 2 on the outer peripheral side surface supporting the outer pillar shown in FIGS. 10-2 (c) and (d), an example is shown in which a new foundation 16 is constructed with a required interval on both side surfaces that are vacant. It is a thing. In this case, the post-construction anchor bars 8 are provided on the existing foundation 2, and a plurality of post-construction anchor bars 8 are provided so as to protrude the required length near the lower end of the column 5. 7, after fixing the tension to the supporting ground, the joining bar 9 of the new foundation 16 and the post-construction anchor 8 of the existing foundation are joined together and added between the joining bars 9 of the two new foundations 16 above the existing foundation 2. The joint reinforcement 9a is arranged and joined together, and the post-cast concrete 20 is placed within the required interval and the upper surface of the existing foundation 2 so that the new foundation 16, the existing foundation 2 and the column 5 are integrated. . And the concrete laid after on the upper surface of the existing foundation 2 becomes the cotter 20a.

  The eleventh embodiment shown in FIGS. 11A to 11C will be described. In this example, a part of the seventh embodiment and the ninth embodiment are combined, and parts common to these examples are denoted by the same reference numerals, and details thereof are omitted. . That is, in the existing foundation 2 at the corner shown in (a) and (b), a required notch portion 14 is provided in advance on two vacant side surfaces, and a plurality of notches 14 and side surfaces are provided. Post-installed anchor bars 8 are provided, and a plurality of insertion holes 12 penetrating the inside of the existing foundation 2 are further provided. After the existing foundation 2 and a new foundation 6 having an insertion hole 12a communicating with the insertion hole 12 at a required interval are provided, and the new foundation 6 is tension-fixed to the supporting ground by the ground anchor 7, the post-construction is performed. The anchor bars 8 and the joint bars 9 are joined together, and a post-cast concrete 10 is placed in the required interval and in the notch 14, and after the post-cast concrete 10 is hardened, a PC steel rod 13 which is a PC steel material. Is inserted from the insertion hole 12a of one new foundation 6 into the insertion hole 12 of the existing foundation 2, and is inserted into the insertion hole 12a of the other new foundation 6, and at the end face of the other new foundation 6, the PC steel bar 13 The nut is tightened at the end with a tension jack, and the existing foundation 2 and the two newly installed foundations 6 are integrated.

  In the existing foundation 2 on the outer peripheral side surface supporting the outer pillar shown in FIG. 11 (c), the new foundation 6 is provided with a required interval on the side surfaces on both sides that are vacant, like the existing foundation 2 at the corner. An example of the construction is shown, which is substantially the same as the structure for the seismic reinforcement of the existing foundation 2 at the corner. The post-cast concrete placed in the notch 14 becomes the cotter 10a.

  A twelfth embodiment shown in FIGS. 12A to 12C will be described. In this example, a part of the fourth embodiment and a part of the tenth embodiment are combined, and parts common to these examples are denoted by the same reference numerals and detailed. Is omitted. That is, in the existing foundation 2 at the corner shown in (a) and (b), a plurality of post-installed anchor bars 8 are provided on each of two vacant side surfaces, and a plurality of Post-installed anchor bars 8 are provided so as to protrude to a required length, and a plurality of insertion holes 12 penetrating the inside of the existing foundation 2 are provided. And after providing the new foundation 16 which has the insertion hole 12a which communicates with the existing foundation 2 and the said insertion hole 12 with a required space | interval, after fixing this new foundation 16 to the support ground with the ground anchor 7, respectively, The post-construction anchor bar 8 and the joint bar 9 are joined together, and an additional joint bar 9a is arranged between the joint bars 9 of the two newly installed foundations 16 on the upper surface of the existing foundation 2 and joined together. The post-cast concrete 20 is placed on the upper surface of the foundation 2 to integrate the new foundation 16 with the existing foundation 2 and the pillar 5. And the concrete laid after on the upper surface of the existing foundation 2 becomes the cotter 20a.

  In the existing foundation 2 on the outer peripheral side surface supporting the outer column shown in FIG. 12C, the new foundation 16 is provided with a required interval on both side surfaces that are vacant, like the existing foundation 2 at the corner. An example of the construction is shown, which is substantially the same as the structure for seismic reinforcement of the existing foundation 2 at the corner, and since the description is duplicated, the same reference numerals are given and the details are omitted.

  A thirteenth embodiment shown in FIGS. 13A and 13B will be described. In this example, a part of the second embodiment is used, and parts common to the second embodiment are denoted by the same reference numerals, and details thereof are omitted. That is, in the existing foundation 2 at the corner that supports the corner pillar 5, a plurality of post-installed anchor bars 8 are provided near the lower end of the pillar 5 facing two vacant side surfaces, respectively, and the newly installed foundation is adjacent to the existing foundation 2. 16, the new foundation 16 is tensioned and fixed on the supporting ground by the ground anchor 7, the post-construction anchor bar 8 and the joint bar 9 are joined together, and the post-cast concrete 20 is cast on the upper surface of the existing foundation 2. The new foundation 16 and the pillar 5 are integrated, and the new foundation 16 and the existing foundation 2 are integrated through the pillar 5. And the concrete 20 post-placed on the upper surface of the existing foundation 2 becomes a cotter part.

  The seismic reinforcement structure according to the present invention has been described with respect to the structure of the existing foundation 2 for the footing formed on the top of the pile foundation 3, but is not limited thereto. Needless to say, it can be applied even to existing foundations such as foundations. In short, is it necessary to construct the new foundations 6 and 16 by providing a necessary interval or joint (gap) between the existing foundation 2 to be reinforced? Or, if a new foundation is provided on both sides of the existing foundation, and the new foundation is tensioned and fixed with a ground anchor that extends into the supporting ground, then it is formed at the required interval, it must be installed on the existing foundation within that required interval. The construction anchors and the joint bars provided on the new foundation are joined together as a reinforced lap joint, and the post-cast concrete is cast and integrated, and a new foundation is constructed on both sides with joints. In this case, after the joint filler has hardened, the PC steel rod, which is a PC steel material, is inserted into the through holes provided in the existing foundation and the new foundation, and the tension is fixed and integrated with the new foundation on both sides. Yes, since the new foundations 6 and 16 are tensioned and fixed on the supporting ground by the ground anchor 7 and then integrated by post-cast concrete or PC steel rod, the high axial force by the ground anchor does not affect the existing foundation Since it is intended to reinforce the pullout strength of existing foundations during an earthquake and prevent the buildings from falling over, it can be widely used for existing foundations of all existing buildings.

DESCRIPTION OF SYMBOLS 1 Existing building 2 Existing foundation 3 Existing foundation pile 4 Underground beam 5 Column 6, 16 New foundation 7 Ground anchor 8 Post-construction anchor reinforcement 9, 19 Joint reinforcement 9a Additional joint reinforcement 10, 20 Post-cast concrete 10a, 20a Cotter 11 Joint (Filler)
12, 12a Insertion hole 13 PC steel bar (PC steel)
14 Notch

Claims (9)

Establish a new foundation at a required interval on at least one side of the existing foundation in the existing building,
The new foundation is provided with a joint anchor protruding in advance on the side facing the existing foundation, and a ground anchor that extends into the support ground and is fixed,
After fixing the ground anchor in tension, the post-construction anchor bar provided on the existing foundation and / or the pillar within the required interval is joined to the joint bar of the new foundation,
A method for seismic reinforcement of an existing building, wherein concrete is placed within the required interval and / or above the existing foundation to integrate the new foundation and the existing foundation and / or the pillar. Establish new foundations with joints on both sides of the existing foundation in the existing building,
Provide a ground anchor that extends into the support ground and fixes to the newly established foundation,
After tension fixing the ground anchor, after filling the joint portion with a filler and curing,
An existing foundation characterized in that PC steel is inserted into the through hole provided in the existing foundation in advance and the through hole provided in the new foundation, and the new foundation and the existing foundation are integrated by fixing the tension to the new foundation on both sides. Seismic reinforcement method for buildings. Establish a new foundation with required intervals on both sides of the existing foundation in the existing building,
The new foundation is provided with a joint anchor protruding in advance on the side facing the existing foundation, and a ground anchor that extends into the support ground and is fixed,
After fixing the ground anchor in tension, the post-construction anchor bar provided on the existing foundation within the required interval is connected to the joint bar of the new foundation to place concrete,
An existing foundation characterized in that PC steel is inserted into the through hole provided in the existing foundation in advance and the through hole provided in the new foundation, and the new foundation and the existing foundation are integrated by fixing the tension to the new foundation on both sides. Seismic reinforcement method for buildings. In addition to forming a notch in the upper part of at least one side of the existing foundation in the existing building, a joint foundation is provided to provide a new foundation.
In addition to providing a ground anchor that extends into the support ground and fixes to the new foundation, a joint bar that protrudes into the notch is provided,
After fixing the ground anchor in tension, the joint portion is filled with a filler and concrete is placed in the notch to form a cotter to integrate the new foundation and the existing foundation and / or the existing foundation in advance. Seismic resistance of an existing building, which is made by inserting PC steel into the through-hole provided in the building and the through-hole provided in the new foundation and fixing the tension to the new foundation on both sides to integrate the new foundation with the existing foundation. Reinforcement method. Establish a new foundation with joints on at least one side of the existing foundation in the existing building,
The newly established foundation is provided with a ground anchor that protrudes from the upper part of the existing foundation in advance and has a ground anchor that extends into the supporting ground and is fixed,
After tension fixing the ground anchor, after filling the joint portion with a filler and curing,
When a new foundation is installed on both sides, an additional joint bar is placed between the joint bars on both sides to connect the joint bars, and concrete is placed on top of the existing foundation to form the cotter integrally. A seismic reinforcement method for existing buildings. In addition to forming notches at the top of the two sides of the existing foundation in the existing building, providing a new foundation with the required spacing,
The newly established foundation is provided with a ground anchor that protrudes in advance on the side facing the existing foundation and on the side corresponding to the notch, and is provided with a ground anchor that extends into the supporting ground and is fixed.
After fixing the ground anchor in tension, the post-construction anchor bar provided on the existing foundation and the notch portion within the required interval is joined to the joint bar of the new foundation and the concrete is cast and integrated. It is characterized in that PC steel is inserted into the through hole provided in the existing foundation in advance and the through hole provided in the new foundation, and the new foundation is integrated with the existing foundation by fixing the tension on the new foundation on both sides. Seismic reinforcement method for existing buildings. Establishing new foundations at required intervals on two sides of existing foundations in existing buildings,
The new foundation is provided with a joint anchor protruding in advance on the side facing the existing foundation and the column, and a ground anchor that extends into the support ground and is fixed,
After fixing the ground anchor in tension, the post-construction anchor bar provided on the existing foundation and the column within the required interval was joined to the joint bar of the new foundation, and / or a new foundation was provided on both sides. In the case of an existing building, an additional joint is placed between the joints on both sides, joined to the joint, and concrete is placed on top of the existing foundation to form a cotter integrally. Seismic reinforcement method. Establish a new foundation with joints on at least one side of the existing foundation in the existing building,
The newly established foundation is provided with a ground anchor that protrudes from the upper part of the existing foundation in advance and has a ground anchor that extends into the supporting ground and is fixed,
After tension fixing the ground anchor, after filling the joint portion with a filler and curing,
After joining the post-construction anchor bar provided on the pillar and the joint bar of the new foundation,
A method for seismic reinforcement of an existing building, characterized in that concrete is placed on top of the existing foundation to integrally form a cotter. A seismic reinforcement structure for an existing building obtained by the seismic reinforcement method according to any one of claims 1 to 8.

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