Not Refereed, Journal of Structural and Construction Engineering (Transactions of AIJ), Architectural Institute of Japan, SEISMIC RESPONSE DRIFT UNCERTAINTY OF UNIFORMLY DESIGNED WOODEN SHEAR WALLS, MATSUDA Masahiro; ISODA Hiroshi; KANEKO Hirofumi; SUMIDA Kotaro; ARAKI Yasuhiro; NAKAGAWA Takafumi, Even if the houses are built based on the same seismic resistance standards, some are damaged or not, and some may or may not collapse during an earthquake. This difference is considered to be due to the difference in local seismic motion or the target design level, the certainty of construction, the degree of deterioration, and the like. Besides, in wooden constructions, the strength and rigidity of the materials used, the joints, and the shear walls are not constant, so-called variations, which causes a difference in the load-deformation relationship of the layers. It is thought that the above factors cause differences in the response deformation during earthquakes. In this study, we discuss variations in response deformation caused by variations in materials, with the same input seismic motion, building design level, and load capacity.

Five or three full-scale box-shaped test specimens manufactured under the same conditions were simultaneously vibrated on the same shake table, and the variation in response displacement was quantitatively clarified. Also, the differences in the metal joints at the ends of the braces and the effects of finishing materials and orthogonal walls on the yield strength were examined. The experiments performed for three different purposes are the A-, B- and C-series shown below (Table 1). The A-series is to examine the variation of the response by simultaneously vibrating 5 test pieces with the uniform wall magnification and construction method on the same shaking table (Fig.1-2, Table2-3). The B-series examines the effect of hardware on the displacement response, using the hardware at the end of the brace with the same wall magnification as a parameter (Fig.8, Table9-10). Finally, the C-series examines the effect of differences in the plane type of hanging walls and frames on the displacement response, as well as the wall magnification (Fig.16-17, Table16-17).

As for the shear walls specimens in the A-series, the variation in response displacement up to the maximum load was small, about 7%, but where the maximum load is exceeded or not exceeded, the variation in response displacement was about 28%. For the brace specimens in the B series, the variation in response displacement increased when buckling in the brace and damage at its ends occurred. It is considered that this is influenced by the material strength and the performance of the brace end hardware. These tendencies were suggested in the C-series to be similar with or without lintel or orthogonal walls., 30 Jul. 2021, 86, 785, 1074, 1083, 10.3130/aijs.86.1074

JOURNAL OF STRUCTURAL ENGINEERING, ASCE-AMER SOC CIVIL ENGINEERS, Seismic Testing and Analysis of Rocking Motions of Japanese Post-and-Beam Construction, Kotaro Sumida; Takafumi Nakagawa; Hiroshi Isoda, From our investigation of the experimental seismic response of post-and-beam wooden buildings with different column joints, we developed a nonlinear three-dimensional distinct element model that is capable of time-history response analysis. This model succeeded in predicting the seismic response of the column-base, such as rocking behavior, which has been difficult. Four types of full-scale post-and-beam wooden structures with various column-base systems were tested on a shaking table with three ground-motion sequences for each type of structure, and their response and performance were investigated. By comparing the model's predictions with the test results, we confirmed the rocking-tracking accuracy of the analysis program. The numerical model was reasonably able to keep pace with the measured experimental response in terms of load-deformation curves, following uplifts and pull-out behavior as observed at the column bottoms in the shake-table tests. The model was also able to predict maximum response acceleration and global interstory drift within 10% accuracy on average. Considering the large uncertainties associated with seismic-collapse predictions, such as complicated nonlinear behavior in frames and joints, these results encourage researchers and designers to understand how these structures respond to earthquakes and how to analyze these structures. (C) 2020 American Society of Civil Engineers., Feb. 2021, 147, 2, Scientific journal, 10.1061/(ASCE)ST.1943-541X.0002901

JOURNAL OF STRUCTURAL ENGINEERING, ASCE-AMER SOC CIVIL ENGINEERS, Seismic Performance of Three-Story Cross-Laminated Timber Structures in Japan, Xiaolan Zhang; Hiroshi Ishoda; Kotaro Sumida; Yasuhiro Araki; Shoichi Nakashima; Takafumi Nakagawa; Nobuhiko Akiyama, To promote the development of cross-laminated timber (CLT) structures, the Japanese Government Notifications on Structural Design of CLT Buildings (GN 611) was issued in 2016. In GN 611, three types of platform-framing CLT structures were classified in the simple calculation method of Route-1. Compared with a platform-framing structure, which has been clarified in GN 611, a balloon-framing structure is superior in shortening the construction period and reducing the number of CLT panels and metal connectors. To study the seismic properties of balloon-framing CLT structures and develop new structures for a CLT building, four full-scale, 3-story CLT structures were tested under quasistatic cyclic loading: Specimen 1 was a platform-framing structure with narrow wall panels; Specimen 2 was a balloon-framing structure with continuous wall panels; Specimen 3 a was platform-framing structure with wide wall panels; and Specimen 4 was a balloon-framing structure with continuous wall panels and glulam beams. In this study, experiments were conducted, and the seismic performance of the balloon- and platform-framing CLT structures were evaluated and compared. The test results indicated that the seismic properties of Specimens 1, 2, and 3 were similar and that the design method of Specimen 1, as specified in GN 611, was applicable for Specimens 2 and 3. Specimen 4 exhibited higher lateral load resistance than the other three specimens. The performance of Specimen 4 depended on the moment-resisting performance of the glulam beam and CLTwall joint. In this case, the moment-resisting performance obtained through the experiment was significantly higher than the predicted performance. (C) 2020 American Society of Civil Engineers., Feb. 2021, 147, 2, Scientific journal, 10.1061/(ASCE)ST.1943-541X.0002897

JOURNAL OF PERFORMANCE OF CONSTRUCTED FACILITIES, ASCE-AMER SOC CIVIL ENGINEERS, Experimental Seismic Response of a Japanese Conventional Wooden House Using 2016 Kumamoto Earthquake Records, Kotaro Sumida; Hiroshi Isoda; Takuro Mori; Kei Tanaka; Solomon Tesfamariam, Immediately after the 2016 Kumamoto earthquake series, a detailed damage assessment of more than 2,500 wooden houses was conducted at Mashiki Town, Kumamoto. Severe structural and nonstructural components damages were observed for buildings designed after the 2000 building standard law. Results of the field investigation were used to identify vulnerable building type, and in October 2017, a full-scale, two-story, Japanese conventional post and beam wood townhouse was tested under the 2016 Kumamoto earthquake series recorded at the KiK-net station. A triaxial shake table testing facility located in Miki City, Japan, was used. The tested building survived the foreshock and mainshock of the Kumamoto earthquake, and the extent of damage reasonably agreed with the result of the survey around the KiK-net station. Results of the experimental tests will help designers and decision makers to understand the seismic response and damage of the test building and come up with mitigation alternatives. (C) 2019 American Society of Civil Engineers., Apr. 2019, 33, 2, Scientific journal, 10.1061/(ASCE)CF.1943-5509.0001267

Not Refereed, Journal of Japan Association for Earthquake Engineering, JAPAN ASSOCIATION FOR EARTHQUAKE ENGINEERING, Survey of Construction Situation in Mashiki Town Two Years After the 2016 Kumamoto Earthquakes, SUMIDA Kotaro; ISODA Hiroshi; INOUE Ryo; MORI Takuro; TANAKA Kei; SATO Toshiaki, The survey was carried out again two years later on buildings that were completely surveyed just after the 2016 Kumamoto earthquake. The purpose of the survey is to quantify the relationship between damage level, construction year, structure type, etc. and the usage of the buildings after two years. This study revealed that about half of the buildings surveyed areas in Mashiki town do not exist. In addition, it was found that the continuous use rate of buildings is higher as the construction year of the affected building is newer, or the damage level is lower. Also, 37% of the continuously used buildings have been repaired, and some of buildings judged to be no damage by the exterior survey have also been repaired. 84% of newly constructed buildings were wooden structure and 71% were single story., 2019, 19, 1, 1_21, 1_33, 10.5610/jaee.19.1_21

WCTE 2018 - World Conference on Timber Engineering, Experimental seismic response of a full-scale Japanese conventional wooden post and beam building, Kotaro Sumida; Hiroshi Isoda; Masahiro Matsuda; Kokoro Yoshida, A full-scale, two-story, Japanese conventional wooden house built in post and beam construction was tested on a triaxial shake table. The main objective of this experimental study was to investigate the dynamic characteristic and the seismic performance of the test building under various base input intensities. The building performed excellently with little damage even following the five major earthquakes recorded in Japan. We identified the good correlation of the overall inter-story drift with damage observed on some panels of the test building., 2018, International conference proceedings

日本木材学会大会研究発表要旨集(完全版)(CD-ROM), Development of fragility curves for buildings by response analysis based on aseismatic diagnosis data in Kyoto City, 海野晴奈; 中川貴文; 五十田博; 荒木康弘; 角田功太郎, 2024, 74th

2024, 42nd

日本建築学会大会学術講演梗概集・建築デザイン発表梗概集(CD-ROM), A basic study on the seismic design method for CLT panel constructions considering the limit of collapse. Part 14: In-plane moment resistance characteristics of the lintel-wall connection from a shake table test., 海野晴奈; 角田功太郎; 三宅辰哉; 佐藤基志; 五十田博; 河合直人, 2023, 2023

日本建築学会大会学術講演梗概集・建築デザイン発表梗概集(CD-ROM), The seismic resistance system and collapse limit for low-rise CLT panel building with metal connectors of conventional wooden houses. Part3: Shake table tests, 角田功太郎; 百瀬奏; 辻拓也; 五十田博; 中川貴文; 中島昌一, 2023, 2023

Oct. 2022, 55, 44, 47

日本建築学会大会学術講演梗概集・建築デザイン発表梗概集(CD-ROM), Seismic Response Analysis of Rocking Motions of Japanese Post-and-Beam Construction, 角田功太郎; 中川貴文; 五十田博, 2022, 2022

2022, 69, 1・2, 93, 99

Refereed, 2021, Introduction international proceedings

日本建築学会構造系論文集(Web), SEISMIC RESPONSE DRIFT UNCERTAINTY OF UNIFORMLY DESIGNED WOODEN SHEAR WALLS, 松田昌洋; 五十田博; 金子洋文; 角田功太郎; 荒木康弘; 中川貴文, 2021, 86, 785

日本建築学会大会学術講演梗概集・建築デザイン発表梗概集(CD-ROM), Study on Seismic Performance of CLT Wall and Steel Beam Hybrid Structure: Part 1: Full-Scale Static Loading Test, 角田功太郎; 荒木康弘; 中島昌一; 谷口翼; 五十田博, 2021, 2021

日本建築学会大会学術講演梗概集・建築デザイン発表梗概集(CD-ROM), Full-scale static loading tests of cross-laminated timber shear walls with replaceable dampers used in balloon framing configuration: Part. 1: Outline of the tests and destruction status after loading, 角田功太郎; 衣笠大樹; 森拓郎; 中川貴文; 荒木康弘; 中島昌一; 北守顕久; 五十田博, Sep. 2020, 2020, 2020, 303, 304

日本建築学会大会学術講演梗概集・建築デザイン発表梗概集(CD-ROM), Full-scale static loading tests of cross-laminated timber shear walls with replaceable dampers used in balloon framing configuration: Part. 2: Design of Joint and comparison between analytical model and test results, 衣笠大樹; 角田功太郎; 森拓郎; 中川貴文; 荒木康弘; 中島昌一; 北守顕久; 五十田博, Sep. 2020, 2020, 2020, 305, 306

日本建築学会大会学術講演梗概集・建築デザイン発表梗概集(CD-ROM), Full Scale 5 story static loading tests of CLT construction with balloon framing constrution, 荒木康弘; 中島昌一; 秋山信彦; 衣笠大樹; 角田功太郎; 五十田博, Sep. 2020, 2020, 2020, 425, 426

日本建築学会大会学術講演梗概集・建築デザイン発表梗概集(CD-ROM), Seismic performance requirement of conventional wooden houses for continued use after major earthquake, 井上涼; 森拓郎; 角田功太郎; 田中圭; 五十田博, Sep. 2020, 2020, 2020, 447, 448

日本建築学会大会学術講演梗概集・建築デザイン発表梗概集(CD-ROM), Seismic response analysis of a collapsed wooden house in 2016 Kumamoto Earthquakes, 難波宗功; 角田功太郎; 中川貴文; 五十田博, Sep. 2020, 2020, 2020, 433, 434

2020, 70th

2020, 43, 209, 212

Oct. 2019, 31, 169, 48, 59

20 Jul. 2019, 2019, 2019, 381, 382

20 Jul. 2019, 2019, 355, 356

20 Jul. 2019, 2019, 2019, 353, 354

20 Jul. 2019, 2019, 2019, 413, 414

Mar. 2019, 58, 593, 596

Refereed, 2019, Introduction international proceedings

Refereed, 2019, Introduction international proceedings

2019, 69th

20 Jul. 2018, 2018, 2018, 31, 32

20 Jul. 2018, 2018, 2018, 35, 36

20 Jul. 2018, 2018, 2018, 33, 34

Mar. 2018, 41, 85, 88

2018, 68th

20 Jul. 2017, 2017, 2017, 425, 426

2017, 67th