Graduation Research in the academic year 2014

International Management of Civil Infrastructure

WANJALA, Richard Makokha

Wanjala Lab photograph

Title of Graduation Research

Numerical Investigations of Vibration-Based Damage Detection in an Artificially Damaged Real Steel Truss Bridge.

Description of the research and activities in the lab.

Bridges are the flagships of our transportation infrastructure, on which our society and the economy of a country heavily depends on. Therefore, continuous monitoring of the health and conditions of the bridges is of paramount significance to bridge engineers.
In this research, a field experiment was conducted on a real simply supported steel truss bridge with some artificial damages applied sequentially and then the bridge modeled in an FEM software, ABAQUS®. The eigenvalue analysis and dynamic response analysis (using white noise excitation) were performed. Finally system identification was done utilizing the feature extraction methods; Multivariate Autoregressive (MAR) model and frequency domain decomposition (FDD). All this was done to monitor the changes in the bridge’s modal parameters and stress redistribution.

Future prospects after graduation

Commence Masters in April 2015.

YAMAMOTO, Moemi

Yamamoto Moemi Lab Photograph

Title of Graduation Research

Optimisation of Debris Collection and Transport after Disasters using Tabu Search

Description of the research and activities in the lab.

This research aims to optimise collection operations of disaster debris. Whenever disasters occur, debris is generated. In case the debris blocks roads, it is important to remove it from them promptly because roads can be part of evacuation routes and they are necessary for transport of relief supplies in emergency. This research tries to answer the question that how to remove disaster debris as promptly as possible with least possible cost and/or time. This question is transformed in a mathematical model, which is solved using a Tabu Search metaheuristics developed in this research. This model is applied to a case study of the Great East Japan Earthquake. This case study would show the effectiveness of the model and the Tabu search metaheuristics for their application in case of future disasters.

Future prospects after graduation

Continue to research in a master course

Structural Mechanics

WANG, Ziran

Wang Lab Photograph

Title of Graduation Research

Long-term bridge health monitoring utilizing the Mahalanobis distance of modal parameters

Description of the research and activities in the lab.

Maintaining civil infrastructure, including bridges, has been a keen technical issue in developed countries and will surely be one in developing countries in the near future. An effective maintenance strategy strongly depends on timely decisions on the health condition of the structure. And it has been widely believed that structural health monitoring (SHM) using vibration data is one of the effective technologies that aid decision-making on bridge maintenance.
This study is intended to utilize a new damage-detecting indicator for long-term bridge health monitoring--the mahalanobis distance(MD) of modal parameters of the bridge. And environmental influences, which proved to be the most disturbing factors in the practice of bridge health monitoring, is dealt with by means of regression method.

Future prospects after graduation

Commence Masters in April 2015

Structural Dynamics

MBITHI, Michael Kinama

Mbithi Lab Photograph

Title of Graduation Research

Reduction of airborne sea salt adhesion on bridge girders by aerodynamic countermeasures

Description of the research and activities in the lab.

In order to achieve effective maintenance and enhanced structural durability it is necessary to reduce amount of air borne sea salt particles adhering to bridge parts. Since Japan is surrounded by the sea, the effect of airborne sea salt is quite high therefore structural performance degradation due to steel corrosion is a serious problem. Sea salt particles are transported by the wind; adhere on a bridge structure at or near the coast and therefore cause corrosion. Reducing the amount of airborne sea salt particles adhering on bridge girders requires application of aerodynamic techniques to change the flow field around the bridge deck. The target I beam girder bridge is modeled and the steady state flow field around the model is analyzed by solving the Reynolds Average Navier Stokes (RANS) equations and employing the k-ε turbulent model. By installing aerodynamic devices, changes in the flow field are analyzed and using meteorological data and airborne salinity concentration the sea salt adhesion amount is then estimated. The relationship between the bridge girder shape and the sea salt adhesion amount is then made clear.

Future prospects after graduation

Evaluating the ability of the established aerodynamic techniques in reducing sea salt adhesion amount by application to a real bridge.

Geomechanics

MITSUYOSHI, Yasuo

Mitsuyoshi Lab Photograph
(on the right)

Title of Graduation Research

Experimental Study on Dynamic Behavior of a Bridge Column Integrated by Multiple Steel Pipes with Directly Connected Piles

Description of the research and activities in the lab.
As you know, there are many earthquakes in Japan. Since the Great Hanshin Earthquake, great efforts have been made to design seismic resistant structures. Then, new type of bridge column, which is composed of four steel pipes interconnected with shear links, and new type of foundation for this bridge column, directly connected piles foundation, has been suggested. In my research, large-scale shaking table experiment of this bridge column with two types of foundation, one is piles with footing another is directly connected piles, is done to evaluate seismic performance. This research can decrease damages from earthquake and save many lives.

Future prospects after graduation

Commence Masters in April 2015 to be a global engineer

Urban Coast Design

SHIMIZU, Yuma

Shimizu Lab Photograph

Title of Graduation Research

On enhancement of energy conservation properties of Moving Particle Semi-implicit method

Description of the research and activities in the lab.

I belong to Laboratory of Urban Coast Design, Professor Hitoshi Gotoh’s Laboratory. I major in MPS method, a particle method for simulation of free surface fluid flows. Two governing equations for fluid flows, Navier Stokes equation and continuity equation, are discretize and solved, then fluid flow is reproduced. My graduation research is to investigate the property of energy conservation of the enhanced MPS method.
Regarding to laboratory life, I feel glad that I can study anytime I feel like since this laboratory mainly focuses on numerical simulations and has a nice academic environment. I can manage my time whatever I like. Also, although the theory of MPS is complicated and takes me lots of time to understand, I can feel really excited to make success. I can really say it’s great to be here.

Future prospects after graduation

Commence Masters in April 2015 to be a researcher

KURASAKI, Ryo

Kurasaki Lab Photograph

Title of Graduation Research

Simulation of bank erosion due to overflow by moving particle semi-implicit method

Description of the research and activities in the lab.

I belong to Laboratory of Urban Coast Design, Professor Hitoshi Gotoh’s Laboratory. I major in moving particle semi-implicit (MPS) method, which is one of the Lagrangian meshfree method to simulate free surface fluid flows. Two governing equations for fluid flows, Navier Stokes equation and continuity equation, are discretize and solved, then fluid flow is reproduced. My research is to simulate bank erosion due to overflow by using MPS method. Especially, I focus on a deformation of bank eroded by flooding water. I examine the applicability of this numerical model by comparing simulation results with experimental ones.

Future prospects after graduation

Work for a trading company from April 2015

KONO, Ketsushi

Kono Lab Photograph

Title of Graduation Research

Simulation of turning vehicles and pedestrians on crosswalk by DEM-based multiagent model

Description of the research and activities in the lab.

I belong to Laboratory of Urban Coast Design, Professor Hitoshi Gotoh’s Laboratory. The title of my graduation research is “Simulation of turning vehicles and pedestrians on crosswalk by DEM-based multiagent model”, where I address the development of the modeling for interactions between cars and pedestrians. This research will contribute to a planning of urban traffics.
There are many challenging things in my laboratory life to understand and organize the system concerning a simulation method. However, when I obtain a good result, I can feel a sense of accomplishment. I think working in the laboratory in Kyoto University gives me very valuable experiences, because I can get pleasure from creating new things by learning cutting-edge science and technology.

Future prospects after graduation

Commence Maters in April 2015 to be an engineer