JP5637357B2 - Seismic reinforcement structure of existing reinforced concrete apartment houses - Google Patents

Description

  The present invention relates to a seismic reinforcement structure of an existing reinforced concrete apartment house, and improves the earthquake resistance of an existing medium- and low-rise apartment house, and can be realized by installing an elevator facility in the earthquake-proof reinforcement structure and making it barrier-free. The present invention relates to a seismic reinforcement structure for existing reinforced concrete apartment buildings.

  In the 1950s and 1940s, a number of five-story low- and high-rise apartments were built throughout the country by the Housing and Urban Development Corporation (current UR City Organization), local governments, and private construction companies.

  FIG. 9 is a front view showing one of the above-described general public middle-to-low (for example, four-story) plate-like apartment houses 50 that have been built in the past, and FIG. 10 is a layout example thereof. It is the shown top view. In this type of apartment 50, a staircase 52 is provided between two adjacent dwelling units 51 and 51 as a basic configuration. From the road level on the ground to the entrance level 53 of each dwelling unit (FIG. 10), the front of each dwelling unit 51 is provided. The stairs 54 are used. Most of these mid- and low-rise apartments 50 are not equipped with elevators despite the aging of residents.

  Moreover, since these apartment houses are designed in accordance with the design standards of the time, they do not satisfy the current seismic design standards. In addition, many years have passed since the building was built, and there are many cases where it is necessary to determine whether to reinforce an existing building or replace it with a new building.

  In that judgment, in the case of rebuilding, since the new building is built on the ruined site, the degree of freedom and safety of the new building is high, but the period between the request for resident relocation, the dismantling of the existing building, and the completion The total cost, such as arrangements for temporary housing and construction costs, will be considerably high. In the case of reinforcement of an existing building, the cost can be reduced, but it is expected that the seismic reinforcement members added to the inside or the outer shell of the existing building will make both the exclusive and shared parts narrow and the usability will deteriorate. The In addition, if the reinforcement extends to the entire building, the period is shorter than in the case of a new construction, but a temporary move may be required. Furthermore, there is a proposal for a reconstructed construction method for existing buildings that has been improved over the entire existing building, such as the “Renaissance Plan” by the UR City Organization. It is said that it will be 80 to 90% of the time.

  In addition to repairs to ensure seismic resistance of existing buildings, as a challenge to improve the living environment, requests for repairs related to barrier-free, such as installing elevators and eliminating stepped parts, taking into account the convenience of elderly residents There is also.

  For example, the invention of Patent Document 1 has been proposed as an example of securing the earthquake resistance of an existing building with respect to these problems. In Patent Document 1, a reinforcing column beam frame having a lattice shape as a whole having the same scale as the building is constructed outside the protruding slab corresponding to the veranda and balcony of the existing building.

  Moreover, the invention shown in patent document 2 is proposed with respect to the installation of the elevator in the existing building. In Patent Document 2, an elevator shaft unit for one layer is manufactured as a precast concrete product at a factory, and this elevator shaft unit is laminated adjacent to a building to be added to the elevator, and a floor between existing buildings is also provided. Proposing to install elevator equipment in existing buildings by laying members.

JP 2009-209585 A JP 2001-199650 A

  In the seismic strengthening structure disclosed in Patent Document 1, a spring slab that becomes a balcony and a veranda is newly constructed on the surface opposite to the existing veranda side of the plate-shaped apartment house, and the spring is provided on both sides of the building. A grid-like column beam structure will be newly constructed using slabs. At that time, each house is characterized by the fact that a new jumping slab is added, but there is no merit in daily life in that a veranda and a balcony are added as an exclusive outdoor part. On the other hand, the old plate-shaped apartment house to be repaired has a south-facing veranda side in consideration of daylighting, and multiple buildings are juxtaposed with sufficient spacing between adjacent buildings. Many were built. In this regard, the seismic reinforcement structure disclosed in Patent Document 1 has a problem that the lighting to the existing building is lowered because a lattice-like column beam structure is constructed on the entire south surface. In addition, even if this column beam frame can improve the seismic performance, an elevator installation cannot be installed using this column beam frame.

  On the other hand, since the invention disclosed in Patent Document 2 is intended only for the extension of an elevator shaft, it is not considered to improve the seismic performance of existing buildings. Therefore, the object of the present invention is to solve the problems of the conventional technology described above, improve the seismic performance without deteriorating the living environment of the existing building, improve the facilities, such as new installation of elevators, elimination of steps, etc. The purpose is to provide an anti-seismic reinforcement structure for existing reinforced concrete apartments.

In order to achieve the above object, the seismic reinforcement structure of an existing reinforced concrete apartment building according to the present invention is an earthquake proof reinforcement structure added to an existing reinforced concrete apartment house consisting of two dwelling units and one staircase structure. A core wall having a wall structure having a recess extending from the ground to the rooftop of the apartment house, a plurality of which are standing upright from the underground support structure at a position away from the room side by a predetermined distance; A seismic frame comprising a plurality of core walls, a roof floor connecting the roofs of the apartment houses, and a roof beam connecting and reinforcing the tops of the core walls. And laid at the entrance height of the dwelling unit on each floor in the staircase room where the staircase provided in the apartment house has been removed, and between the access wall and the core wall connecting the earthquake resistant frame and the apartment house And a passage floor and a passage portion which circuited, the passageway floor and fixed held between the seismic frame side wall side of the stairwell, characterized in that the Housing and Retrofit by the seismic frame .

The core wall is preferably erected by stacking a plurality of precast reinforced concrete structural units on the underground support structure .

The passage floor is preferably reinforced with intermediate beam portions .

It is preferable to install an elevator facility or an outer staircase in the recess of the core wall .

  It is preferable that the underground support structure has a frame structure including underground beams and connecting beams that connect the underground beams, and the core wall is erected on the underground support structure.

  ADVANTAGE OF THE INVENTION According to this invention, there exists an effect that a seismic performance can be improved, barrier-free improvement, such as new installation of an elevator etc., elimination of a level | step difference, can be achieved, without reducing the living environment of the existing building.

The front view of the existing apartment house which attached the earthquake-resistant frame as a seismic reinforcement structure of the existing reinforced concrete apartment house of this invention. The top view (1st floor plane) which showed the attachment aspect of the existing apartment house and earthquake-resistant frame shown in FIG. The top view which showed the attachment aspect of the existing apartment house and earthquake-resistant frame in a reference | standard floor. The top view which showed the attachment aspect of the existing apartment house and earthquake-resistant frame in a rooftop floor. The partial block diagram which showed the connection part of a core wall and an underground support structure. The partial block diagram which showed the connection part of a core wall and a passage floor. The front view which showed the attachment aspect of the other Example of an earthquake-resistant frame. The top view and partial sectional view which showed the attachment aspect and detailed structure of the seismic frame shown in FIG. The building front view which showed an example of the conventional existing apartment house. The top view in the standard floor of the existing apartment house shown in FIG.

  Hereinafter, the following examples will be described with reference to the accompanying drawings as modes for carrying out the seismic reinforcement structure of an existing reinforced concrete apartment house of the present invention.

  FIG. 1 is a front view showing a mode in which the seismic reinforcement structure of the present invention is constructed in the middle- and low-rise plate-shaped apartment house (four-story: one-layer, six units, two units, one staircase) shown in FIG. FIG. 4 is a plan view showing a planar configuration of the seismic reinforcement structure on each floor (first floor, reference floor (2-4 floor in this example), rooftop).

  As shown in FIG. 1, the seismic reinforcement structure 10 of the present invention (referred to as a seismic frame 10 in the embodiment) is roughly divided into the illustrated existing apartment house 1 (hereinafter referred to as an existing building 1). An underground support structure 15 extending in the direction of the beam, and three core walls (two end core walls 21 and one central core wall 25) whose roots are supported by the underground support structure 15; The reverse beam portion 30 is erected on the rooftop floor 45 and the passage floor 40 to each dwelling unit. Further, the inside of the central core wall 25 is used as an elevator shaft so that an elevator facility can be installed inside. Furthermore, an external staircase 35 that can be moved up and down to the passage floor 40 of each floor is provided as an incidental facility.

  The above-described members and the earthquake-resistant frame 10 as an earthquake-proof reinforcement structure constituted by these members will be described with reference to the accompanying drawings. As shown in FIGS. 1, 2, and 5, the underground support structure 15 is constructed in the ground at a position separated by a predetermined distance outside the staircase 2 of the target existing building 1. The length is longer than the length over the three staircases 2 provided in the existing building 1, and two underground beams 17 whose bottom surface is constructed integrally with the bottom plate 16 at both sides of the bottom plate 16, It is comprised from the connection beam 18 which connects the upper part of the two underground beams 17 in a predetermined position. In the present embodiment, each of these members is composed of a reinforced concrete structure having a direct foundation structure built in a space excavated to a predetermined depth. In addition, as shown in FIG. 5, the lower end of the core wall 20 (21, 25) is arranged so as to be rigidly joined to a part of the underground beam 17 to form an integral concrete structure. .

  The configuration of the core wall 20 (21, 25) will be described. Further, as shown in FIGS. 1 and 5, in the vicinity of both ends on the bottom plate 16 of the underground support structure 15, end core walls 21 having a U-shape in plan view are arranged in the direction of the row of the existing building 1. A central core wall 25 that also serves as an elevator shaft, which will be described later, is provided upright at a substantially central position. As shown in FIG. 1, the core walls 20 (in the case where the end and the center are not distinguished are simply referred to as the core walls 20) have a height substantially equal to the rooftop height of the existing building 1. Each core wall 20 functions as a constituent member of the seismic frame 10 but is designed as a reinforced concrete self-supporting structure. Needless to say, the number of the core walls 20 (21, 25) can be set as appropriate depending on the length in the longitudinal direction (the number of dwelling units) and the number of installed elevators. Further, the cross-sectional shape of the core wall 20 is not limited to the U-shape, but may be an appropriate shape as long as it has an L-shape with the passage floor 40 (FIG. 2) open, or can secure a predetermined cross-sectional rigidity and planar space. Can be set. In this embodiment, the core wall 20 is made of a precast concrete product manufactured as a unit at a factory, and the core wall unit made of precast concrete is connected upward using a mechanical joint (not shown). Then, it is constructed as a predetermined self-supporting structure by stacking. Of course, it is also possible to construct on-site concrete by performing bar arrangement and formwork assembly at the site.

  As shown in FIGS. 1 and 4, the top of the core wall 20 is connected by a rooftop floor 45. And the reverse beam part 30 which connects the two wall-shaped beams 31 in four places is constructed | assembled on the roof floor floor 45. As shown in FIG. The reverse beam portion 30 has a structure rigidly joined to the top portion of each core wall 20 connected via the roof floor 45. As a result, the existing building 1 is erected on the underground support structure 15 at the side surface position on the staircase side and has a height to the rooftop, as viewed from the front, and is downward. It can be handled as an E-shaped structure in which the seismic frame 10 is connected and which is seismically reinforced.

  Next, the relationship between the configuration of the passage floor 40 and the seismic frame will be described. As schematically shown in FIG. 6, side edges of the passage floor 40 laid on each reference floor are connected and fixed to the side surface of the core wall 20 of the earthquake resistant frame. On the other hand, the floor end portion of the passage floor 40 extended to the staircase side of the existing building 1 is connected to the outer wall surface of the staircase 2 of the existing building 1, and is an access portion (described later) to each entrance of the existing building 1. ). In the existing building 1 to which the seismic frame 10 is added in this way, when an earthquake occurs, the seismic force input to the existing building 1 is transmitted to the seismic frame 10 via the passage floor 40 of each floor. Since the seismic frame 10 is designed to have a predetermined seismic resistance against the earthquake motion input from the existing building 1, the safety of the existing building 1 is ensured by the seismic frame 10. Note that the cross-sectional design of each part of the seismic frame 10 is preferably determined by modeling the seismic frame 10 as a linked structure with the existing building 1 and using a short-term design load to determine the reinforcement arrangement and the structural cross section.

  A detailed configuration of the passage floor 40 will be described. In the existing building 50 shown in FIG. 8, there is a staircase 52, and a folded staircase 54 made of reinforced concrete is formed in a reinforced concrete wall 55, a central handrail portion 56, and a landing 57 that define the staircase 52. It was provided to be supported. In the present invention, as shown in FIG. 2, the existing staircase portion is removed from the reinforced concrete wall portion of the staircase, and the aisle floor 40 is installed on each floor so that the height matches the entrance level of each door. As shown in FIG. 3, the passage floor 40 is provided at a right angle to the passage portion 41 parallel to the existing building 1 and the passage portion 41, and the passage to the staircase 2 or the entrance / exit to each doorway 3. And an access unit 42 functioning as

  As shown in FIGS. 3 and 5, the passage floor 40 of each floor is fixedly supported on the side surface of the core wall 20 constituting the seismic frame 10, and the access portion 42 is at the height of the entrance 3 of each door. It is fixedly supported by a reinforced concrete wall (structural wall) 4 that partitions one staircase 2. Although this access part 42 is connected to the structural wall 4 in the existing building 1, it can be expected to fulfill a function as a shearing cotter in the direction of crossing in the event of an earthquake. The passage floor 40 on each floor supports the passage floor 40 on each upper layer by a steel pipe pillar 48 (see FIGS. 2 and 3) schematically shown on the floor plane. However, since the passage floor 40 itself is fixed to the core wall 20 and the structural wall 4 of the staircase 2 of the existing building 1, these steel pipe columns 48 have the flatness of each passage floor 40 at the time of constant load action. The purpose is retention. Further, the passage floor 40 is used as a passage, and handrail walls 49 (see FIG. 1) are erected on both sides along the passage as a safety ensuring member. In this embodiment, a precast concrete wall is used for the handrail wall 49 and is attached along the edge of the passage floor 40 of each floor by a post-construction anchor (not shown).

  An elevator 5 (not shown) is accommodated in the central core wall 25 located at the center of the passage floor 40. In this embodiment, considering that the central core wall 25 has high rigidity and that no additional facilities such as a machine room are provided, the machine roomless type elevator 5 is provided. The elevator 5 stops at the level of the passage floor 40 of each floor. Since the aisle floor 40 is set at the same level as the entrance 3 (FIG. 3) level of each door, when an elevator is used, each door can be accessed without going up and down stairs. Thus, in this seismic reinforcement structure, barrier-free is also achieved.

  With respect to the elevator 5 installed in the center of the building, the outer staircase 35 (FIGS. 1 and 3) functioning as an evacuation route is installed using two end core walls 21. A support frame (not shown) of the outer staircase 35 is made of steel, a steel folding staircase 36 is incorporated in the support frame, and an intermediate landing 37 is provided in the end core wall 21. On the other hand, as shown in FIG. 6, the step 38 for entering and exiting the staircase 35 is provided at the same level as each passage floor 40 (in FIG. 6, the staircase portion is not shown).

  The seismic frame 10 described above contributes particularly to improving the seismic resistance in the direction of the beam of the existing building 1. However, if seismic reinforcement in the beam-to-beam direction is required for seismic design, A beam structure 32 having a structure similar to the reverse beam 30 can be installed between the floor 45 and the existing building 1 to improve the earthquake resistance in the inter-beam direction. In addition, it is also preferable to add an underground support structure 15 connected to the direct foundation portion of the existing building 1 in the underground part.

  FIG. 7 and FIG. 8 show another embodiment, in addition to the reverse beam 30 provided on the roof floor, an intermediate floor (in this embodiment, the intermediate beams 22 and 23 and the connecting beam 24 on the lower surface of the passage floor 40 on the third floor). In this embodiment, as shown in Fig. 7, the beam of the reverse beam 30 on the roof floor 45 can be reduced, and as shown in Fig. 8, 3 The passage portion 41 of the floor passage 40 is widened to the extent including the core wall 20, and as shown in the cross sections (I) and (II), the intermediate beam 22 and the passage integrally formed with the handrail wall 49 in appearance. Reinforcement beams 23 that support the intermediate position of the floor 41 are provided, and each core wall 20 is connected at the intermediate height of the building. (II) The handrail wall 49 and the connecting beam shown in the cross section The end of 24 is a structural reinforcement (not shown) on the wall side of an existing building, a mechanical joint, etc. It is preferable to connect by.

  The underground support structure 15 shown in FIG. 7 has a structure in which each core wall 20 is erected on the footing 19 supported by the foundation pile P. Thus, it is preferable to select the foundation type suitable for the ground condition where the existing building is located, such as a direct foundation and a pile foundation.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims. In other words, embodiments obtained by combining technical means appropriately changed within the scope of the claims are also included in the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Existing building 2 Staircase 5 Elevator 10 Seismic frame 15 Underground support structure 16 Bottom board 17 Underground beam 18 Connection beam 20 Core wall 21 End core wall 22, 23 Intermediate beam 25 Central core wall 30 Reverse beam 35 Outer staircase 40 Passage Floor 42 Access section 45 Rooftop floor

Claims (5)

A seismic reinforcement structure added to an existing reinforced concrete apartment house consisting of two dwelling units and one staircase structure,
From a wall structure having a recess extending from the ground level of the apartment house to the rooftop, a plurality of which are erected from the underground support structure at a predetermined distance from the staircase side of the apartment house A plurality of core walls, a rooftop floor connecting between the tops of the plurality of core walls, and a rooftop of the apartment house, and a roof beam part connecting and reinforcing the tops of the core walls. A constructed seismic frame,
An access part connecting the earthquake-resistant frame and the apartment house and a passage part connecting the core wall are laid at the entrance height of the dwelling unit on each floor in the staircase room where the stairs provided in the apartment house are removed. A passage floor having
A seismic reinforcement structure for an existing reinforced concrete apartment house, wherein the passage floor is fixed and held on the wall side of the staircase and the earthquake resistant frame side, and the apartment house is seismically reinforced with the earthquake resistant frame . The seismic reinforcement structure for an existing reinforced concrete apartment building according to claim 1, wherein the core wall is formed by stacking a plurality of precast reinforced concrete structural units on the underground support structure. The seismic reinforcement structure for an existing reinforced concrete apartment building according to claim 1 , wherein the passage floor is reinforced with intermediate beam portions .   The underground support structure comprises a frame structure having underground beams and connecting beams connecting the underground beams, and the core wall is erected on the underground support structure. Item 4. The seismic reinforcement structure for an existing reinforced concrete apartment building according to item 1. 2. The seismic reinforcement structure for an existing reinforced concrete apartment house according to claim 1, wherein an elevator facility or an outer staircase is installed in the recess of the core wall.

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