Procedia Engineering最新文献

A constructivist research methodology elucidated the evolved layers of risks in a sampaguita growing community in the Philippines. Integration of indigenous and scientific knowledge was a crucial process in livelihood disaster risk reduction and resilience building. Resilience processes empowered the marginalized community to escape chronic poverty and collectively act on other constraints including climate change-related risks. The resilience process of collective adaptation was a capability manifestation of making a choice to develop livelihood capitals in the face of disaster risks in a manner that does not degrade the natural resource base of the valued sampaguita livelihood.

The 2004 Indian Ocean Tsunami prompted a relocation process of an unprecedented scale in Sri Lanka, relocating thousands beyond the government imposed coastal buffer zone. Amidst the relocatees were thousands of children whom were exposed to multiple risks and stresses. These impacts caused by relocation remain largely unexplored. This paper investigates the impact of involuntary relocation, experienced by children relocated to Cinnamon Garden settlement and Tea Garden settlement of Galle district, Sri Lake. The paper focuses on (a) what are the impacts children experienced due to forced relocation?, (b) What is the nature of those impacts?, (c) What is the possibility of using a risk model to identify these impacts? Case studies were conducted with a purposively selected sample of individuals whom were relocated as children. The findings suggests that children suffered from social impacts such as disruption of social relationships failing to develop new social networks, decline in education levels and victimized to bullying and discrimination. The study successfully employed the Michael Cernea’s (2000) impoverishments risks and reconstruction to identify key negative and positive impacts of forced relocation, initiating the development of a risk model that can specifically identify the impact of relocation on children.

A damage-based design procedure has been developed by the authors to predict the damage evolution and the stiffness degradation in polymeric composite laminates under fatigue loading. For a safe and reliable design against fatigue degradation and failure, the initiation of the main damage mechanisms (off-axis cracks, delamination and fiber failure) as well as their evolution are considered and suitable models are proposed for the quantitative assessment of the lifetime associated to each mechanism. In parallel, the stiffness degradation deriving from the damage evolution over the fatigue life is properly described. After the illustration of the overall damage-based strategy, the paper discusses in details the analysis and modelling of the off-axis crack initiation and propagation. The initiation of cracks in the off axis plies has been proved to be the consequence of a damage process occurring at the microscopic scale since the early stages of fatigue. On this basis, crack initiation prediction is based on the use of local stress parameters: Local Hydrostatic Stress, LHS, and Local Maximum Principal Stress, LMPS, depending on the local degree of multiaxiality of the stress state and accounting for the statistical distribution of the local laminate strength. The propagation phase is then quantified by using a conventional fracture mechanics approach. The model has been implemented in a Matlab procedure for the quantitative evaluation of the crack density in each ply of a laminate during its entire fatigue life. The knowledge of the crack density trend allows the description of the laminate stiffness evolution taking advantage of another model recently developed by the authors, valid for a generic laminate configuration and accounting for the interaction between cracks in the neighbouring plies.

This paper presents a newly developed mesoscopic model with grid-based structure for building evacuation simulation. The evacuation space in this model is discretized into cells with larger size than that of the microscopic models. This mesoscopic model directly computes the density flow between the cells governed by the density flow algorithm. The computation speed is higher than the traditional cellular automata model in which the movements of all pedestrians should be tracked for calculating the crowd density. To test the feasibility of this model, we applied it to a typical scenario in which pedestrians evacuate from a square room with single exit and conducted parameter sensitivity study on the length of the time step δ. The simulation results show that, within a valid range, changing δ only has minor influence on the evacuation process. We can directly identify area with high density as bottleneck from dynamically changed density map even the relatively large time step is adopted. In addition, the commercial package AnyLogic was used to benchmark the performance of this model. The results show that the mesoscopic model discerns evacuation patterns in more details compared to the macroscopic models and with higher efficiently computational speed than the microscopic models.

The potential of risk communication as tool for reducing the devastating impacts posited by disaster hazards on human lives and property has been discussed extensively in literature. Most risk communication studies and strategies focus on awareness creation and education on disaster hazards. However, awareness creation and education on disaster hazards do not necessary translate into preparatory attitude and behaviour towards disaster hazards. Frantic efforts are required to persuade and motivate people at risk to convert hazard awareness and education into preparation towards disaster hazards. Against this backdrop, this paper develops a conceptual model through literature review to facilitate and enhance disaster preparedness through risk communication.