Probabilistic post-earthquake restoration process with repair prioritization of highway network system for disaster resilience enhancement

Comprehensive realization of post-earthquake restoration process for highway network considering repair prioritization are necessary for preparing effective countermeasures to restore transportation service and social activity in seismically active and automobile dependent regions like broader Los Angeles area quickly. Since the progress and the time to achieve full-recovery realistically change depending on repair orders and reconstruction works, restoration strategies without taking into account actual restoration phenomena negatively affect decision-making, efficient recovery, damage mitigation effort and network resilience enhancement.For dealing with these concerns, a probabilistic model to simulate post-earthquake restoration process of highway network is developed with consideration of repair prioritization and reconstruction constraint in this research. Analytic Hierarchy Process, prioritizing algorithm, is used to decide bridge repair orders based on initial damage state due to earthquake and priority weight of four criteria; difficulty, importance, urgency and cost. Numbers of available construction labor around the target region is applied for constraint of repair work progress. The recovery passage of bridge, the critical component of highway restoration process, is modeled probabilistically based on Markov Chain process, Uniform distribution and Normal distribution. As performance of highway network, drivers' delay and trip opportunity loss over entire recovery period are estimated by conducting traffic network analysis through origin-destination matrix, gravity model and user equilibrium model considering the models of trip reduction and traffic demand recovery. The adequacy of developed model is then verified by the documented recovery records and loss estimations of Northridge earthquake.As an application study, a regional possible scenario earthquake is applied to the established methodology implemented in the highway network system of Los Angeles and Orange counties. A number of simulations through Monte Carlo technique to express restoration processes corresponding to several repair prioritizations are presented by restoration curves and loss estimations. The analyzed results show that the developed procedure can simulate numerous thinkable recovery scenarios according to repair orders and contribute to decision-making for choosing the best suited repair prioritization for minimizing loss and maximizing resilience. Moreover, the basic scheme of this innovative technique can be applied to evaluation of restoration process of other infrastructure network systems and other disasters

フランス南東部ボコンチアン堆積盆における白亜紀Aptian期海洋無酸素事変発生時の海洋の酸化還元状態 : 生痕学的手法および地球化学的手法による高時間分解能復元

京都大学0048新制・課程博士博士(理学)甲第15157号理博第3522号新制||理||1514(附属図書館)27635京都大学大学院理学研究科地球惑星科学専攻(主査)准教授 前田 晴良, 教授 大野 照文, 教授 小畑 正明学位規則第4条第1項該当Doctor of ScienceKyoto UniversityDA

Intelligent damage mitigation for BWR nuclear reactors

Chapter 611This paper deals with light water reactor, particularly BWR type nuclear power plants, similar to Fukushima Dai-ichi Nuclear Power Plant with reactors equally vulnerable to core-melt accidents. It first re-iterates the observations and assertions made by Shinozuka (Shinozuka 2012) to recognize that the core-melt is the most critical damage event that must be mitigated by aggressive mitigation procedures if it cannot be prevented. In this regard, it is noteworthy to observe that U.S. Nuclear Energy Institute (NEI) recently intro-duced a procedure FLEX (NEI 2012) for emergency preparedness. This paper however proposes a different procedure as promoted by Shinozuka earlier (Shinozuka 2012) which is now named “Direct Core Cooling System” (DCCS). DCCS is developed making use of mobile closed-circuit water chilling system in such a way that pumps, a part of this system, are (1) directly connected by pipes to the core, (2) while minimizing their connections with any other reactor components. (1) and (2) above indicate the care that must be exer-cised not to get trapped by 3 pitfalls related to such connections. Any one of these pitfalls if trapped can com-promise effectiveness of DCCS. The mobile water chilling system is originally introduced to similar line of research by Cheung (Cheung 1991 & 2012). The cooling action by DCCS takes place as soon as intelligent sensors in the sense of engineering cybernetics detect initial sign of core-melt, and contain the core-melt lead-ing it to a cold shut down

Explosibility assessment of dusts produced in the recycling process of electrical appliances

Explosibility of dusts produced in the recycling process of electrical appliances was investigated. Polyurethane and plastic dusts, produced by shredding discarded electrical appliances, were mainly used as the sample. Various explosivity indexes, such as the minimum explosive concentration, K$_{\rm st}$ value, the maximum explosion pressure, the influence of coexisting explosive gases on the explosibility of dusts, the oxygen concentration to reduce the risk of dust explosion, and the ignition temperature of the dust cloud were examined. These experimental results were applied to improve the safety of operation of recycling facilities

Explosibility assessment of dusts produced in the recycling process of electrical appliances

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