Kyushu University Academic Staff Educational and Research Activities Database
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Yukihide Kajita Last modified date:2019.06.20

Associate Professor / Structural Analysis and Earthquake Engineering
Faculty of Engineering


Graduate School
Undergraduate School
Other Organization


E-Mail
Homepage
http://www.doc.kyushu-u.ac.jp/shindo/Members/kyokan/kajita.html
Sorry, the web page in English is under construction. .
Phone
092-802-3377
Fax
092-802-3377
Academic Degree
Dr. (Eng.)
Country of degree conferring institution (Overseas)
No
Field of Specialization
Structural Engineering, Earthquake Engineering
Total Priod of education and research career in the foreign country
01years00months
Outline Activities
Research: I have conducted both the experiment and the analysis to evaluate the seismic performance of the highway bridges. Particularly, I focus on the collision between the superstructure and the abutment and the seismic safety of the damaged bridges.

Education: I have the chair of dynamic mechanics and vibration control.

Social activities: I join the JSCE (Japan Society of Civil Engineers) , the JAEE(Japan Association for Earthquake Engineering) and so on.
Research
Research Interests
  • Seismic response analysis for underground pipe in soft ground considering irregularity of base surface
    keyword : liquification, underground pipe
    2015.04.
  • Estimation of slump of the bridge abutment due to soil liquification
    keyword : liquification, abutment
    2013.04.
  • Estimation of the risk of trafficability for highway bridges using the ground excitation records
    keyword : ground excitation records, trafficability, earthquake
    2009.04.
  • Seismic evaluation for the bridges subjected to a long duration seismic excitation
    keyword : seismic excitation, long duration
    2008.04.
  • Resistance characteristic of abutment with consideration of back fill soil
    keyword : abutment, back fill soil
    2009.04~2013.03.
  • Seismic evaluation for the steel truss bridges considering with the corrosion and the deterioration
    keyword : Steel truss bridge, Redundancy, Deterioration
    2008.04.
  • Determination method of partial safety factors for the buckling design of the steel piers
    keyword : partial safety factors, steel pier, local buckling
    2006.04~2008.03.
  • A proposal on the desing method of the shock absorbing rubber
    keyword : Shock absorbing rubber, the collision between the girders
    2005.04.
Academic Activities
Papers
1. Yukihide Kajita, Kazuki Onoda, Taiji Mazda, Kunihiko Uno, Takeshi Kitahara, Investigation on the effect of countermeasures for subsidence at the approaching areas of abutments, Interdependence between Structural Engineering and Construction Management , GFE-12, 2019.05, The purpose of this study is to confirm the effect of soil improvement methods on preventing ground subsidence at the back of abutments. Earthquake seismic analysis is performed for three models. One is a model with no ground improvement. Next is a model with deep mixing method. The third is the model with lightweight banking method. As a result, from the perspective of the passage possibility of the emergency vehicles, both the deep mixing method and lightweight banking method are effective in preventing ground subsidence at the approaching area of abutments. However, in the case of the deep mixing method, it is found that the maximum bending moment of the pile under the liquefaction layer increases because a lump of improved rigid soil that falls down toward the piles..
2. Mujtaba Amin, Yukihide Kajita, Taiji Mazda, Numerical Simulation of Pounding Effect on Damage Assessment of an Abutment for Highway Bridge, Proceedings of the 7th Asia Conference on Earthquake Engineering, Paper ID 0009, 2018.11, The current study mainly focuses on the impact damage assessment of the abutments considering the non-linearity of backfill soil which has not ever quantitatively estimated. The numerical simulation of pounding effect on four types of the abutments with wing wall variation in shapes and dimensions were carried out using the explicit FE code LS-DYNA. The pounding scenario was simulated by the initial impact velocity on the entire nodes of the superstructure. The numerical models are capable of simulating the nonlinearly of backfill soil, damage of concrete and yielding of reinforcement steel with strain rate effect behavior of concrete and steel reinforcement. The study indicates that the response displacement and the impact force on the back wall are affected by the non-linear backfill soil and wing wall variations. At the initial instant of impact, there is No significant effect on the impact forces whereas, for the rest of the time, the impact force on the back wall slightly decreased and the abutment displacement at the crown of back wall increased due to soil non-linearity. In the case of low impact velocity, damage only occurs at the base of the back wall whereas, in the case of maximum velocity impact, the damage spread over the entire Back wall and damage to the entire abutment was confirmed. In the design, only one impact is considered. However, in a real situation, a few or several impacts would occur during an earthquake. So, if the damage to abutment is predicted precisely, the non-linear property of backfill soil should be considered..
3. Hazarika Hemanta, N. P. Bhandary, Yukihide Kajita, Kiyonobu Kasama, Kenichi Tsukahara, POKHAREL RAMESH KUMAR, The 2015 Neal Gorkha Earthquake: An overview of the damage, lessons learned and challenges, The official journal of the international association of lowland technology, 18, 2, 105-118, 2016.09, This paper describes the damage brought by the 2015 Nepal earthquake to urban infrastructures, modern and traditional buildings as well as some word heritage sites in and around Kathmandu city. The paper also focuses on a disaster brought to a hydropower plant by the compound action of a previous landslide and this time earthquake. Some of the possible reasons for such damage were brought to light, and challenges of the geotechnical community towards the retrofitting and recovery of the devastated structures were discussed..
4. Yukihide Kajita, A Horizontal Loading Test and Its Simulation Analysis of the Abutment Model with Backfill Soil
, Proc. of the 2014 Taiwan-Japan Workshop on Structural and Bridge Engineering, 2014.05.
5. Yukihide Kajita, Tomohiro Kobayashi, Hisanori OTSUKA, Investigation on the risk of traffic passage by the damage of girder and abutment due to severe earthquakes
, Safety, Reliability, Risk and Life-Cycle Perormance of Structures and Infrastructures, Paper No. 786, Taylor & Francis Group, London, 2013.6, 2013.06.
6. Yukihide Kajita, Hisanori OTSUKA, Yuki Fujiyoshi, A Horizontal Test and Its Simulation Analysis of the Abutment Model with Backfill Soil
, Proc. of the 15th World Conference on Earthquake Engineering, Paper No.0339(CD-ROM), 2012.09.
Presentations
1. Yukihide Kajita, 小林 智宏, Hisanori OTSUKA, Investigation on the risk of traffic passage by the damage of girder and abutment due to severe earthquakes, International Conference of Safety, Reliability, Risk and Life-Cycle Performance of Structures and Ingrastructures, 2013.06.
Membership in Academic Society
  • Kyushu Association for Bridge and Structural Engineering
  • Kyushu Society for Engineering Education
  • The Japanese Geotechnical Society
  • Japan Society of Civil Engineers
  • Japan Concrete Institute
  • Japanese Society of Steel Construction
  • Japan Association for Earthquake Engineering
Educational
Educational Activities
Mechanics (Rigid Body and Elastic-Plastic Material), Structural Analysis (Frame Model, Finite Element Model), Dynamics (Mass system)
Social
Professional and Outreach Activities
None.