Volume 4 Issue 1
Authors: Nawari O. Nawari; Michael Porter; Tilson L. William
Abstract: The 2004 Indian Ocean tsunami caused enormous devastation of homes, property, and infrastructure over vast coastal areas in more than eight countries in the region. The need for adequate shelter became an emergency of an unprecedented scale. Such a large scale of devastation presents an opportunity for engineers and architects to design without the normal restrictions of surrounding context and affect social change through good design. Disaster Relief has been traditionally thought of in the realm of temporary structure, a structure that must be transported and erected at the place of the disaster. With the glut of aid, the humanitarian aid response to the 2004 Indian Ocean Tsunami was 14 billion US dollars. It certainly seemed to be the easiest answer to spend much on a structure, transport it and simply build it on site as the most efficient and timely answer. The failure comes in the ill consideration of the site and lack of appropriate sustainable solutions for a permanent shelter. This research seeks to provide a solution for disaster relief that addresses a path from a provided transitional structure (usefulness measured in years not months) to a permanent architecture. It has also been shown that “…transitional” may be a misnomer, since many people never leave these homes, nor are “the homes upgraded”. Relief structures have failed to anticipate needs of growth and daily life sustaining activities that go beyond the immediate need of shelter. The needs of shelter are predictable: roof, enclosure, windows, doors, etc… but there are shortfalls in considerations for expansion and needs for clean water, food storage and cooking and other life sustaining functions that go programmatically beyond “shelter”. This gap in the goal and reality of aiding the affected people will attempt to be bridged by a modular framework that provides the flexibility to grow, improve and respond to make a quicker path to their normal permanent lifestyle. The framework will address multiple needs in negotiating the requirements of a non-permanent transitional structure. It will accept numerous infill methods, both provided and vernacular. In addition to those basics, more frameworks can allow the plan to grow and be adapted to the different programs of each occupant and different typologies altogether, from individual to community level concerns. Special attention is given to such concerns as security, food cooking and distribution, and sanitation that are all typically omitted in a shelter design.
Keywords: Disaster Relief Structure; Structural Framework; Transitional Structure; Permanent Structure Relief Shelter; Disaster Relief Architecture
Authors: L. Palizzolo; S. Benfratello; G. Campione
Abstract: Catalan vaults are a peculiar type of low thickness vaulted brick masonry structure. Knowledge of load-deflection response and load bearing capacity are important aspects to consider with the aim of preserving these structural members as part of the cultural heritage. In order to investigate these aspects, complete knowledge of the constituent materials and geometry (dimension, thickness, constructive section) is necessary in such a way as to predict the load-deflection response and the effective load-carrying capacity; the latter can be determined utilizing simplified models (limit analysis) or by means of a numerical analysis (finite element method). With this aim, the structural behaviour of a Catalan vault found in an ancient building in Palermo (Italy) is studied, through an experimental investigation including material characterization and loading test on a full-scale vault. A numerical structural analysis is carried out utilizing an appropriate nonlinear finite element model. The experimental program consisted of on compressive and flexural tests on masonry units and single blocks. From the theoretical point of view, after the identification of an appropriate constitutive model based on the experimental results, a numerical analysis of the vault is performed to study the serviceability condition and the impending collapse one. The obtained results confirm the remarkable structural features of such vaults representing an important step related to the restoration of ancient structures as well as to the design of new ones.
Keywords: Catalan Vaults; Experimental Analysis; Constitutive Model; Numerical Analysis; Structural Behaviour
Authors: Rou-Xuan Lee; Steve Kardinal Jusuf; Nyuk-Hien Wong
Abstract: Geometry (GEO) is one of the urban morphological variables that has effects on microclimate within the urban canopy level (UCL). It is usually quantified in previous researches by different aspect ratios, which have a basis on the buildings’ individual height (H), width between each other (W) and their buildings’ longitudinal length (L), e.g. H/W, L/H or L/W. In this paper, the impact of different morphological scenarios for GEO variation on external ventilation levels within a typical high-rise Housing and Development Board (HDB) residential estate (or precinct) in Singapore, is analyzed through a parametric study exercise. The GEO values are quantified by using the author-proposed Maximum Hydraulic Diameter (HDMax). Two types of common high-rise HDB block types are examined – point and slab blocks, in two types of configurations: (i) geometrical height variation and (ii) geometrical width variation. Numerical studies are done by utilizing a commercial computational fluid dynamics (CFD) code named Star-CCM+. External ventilation levels are quantified by using the area-averaged Wind Velocity Ratio (VR) index, an indication of the average outdoor ventilation potential within an estate at a certain level above ground. Measurements were taken at both the pedestrian and mid-levels under different wind orientations. The final results indicated that in general, GEO is positively related to VR and concluded the usefulness of using HDMax instead of the common aspect ratios of canyons proposed by previous researchers, of which the scale and absolute size were not reflected and produced different gradients of relationship with VR under different geometry range values. Case studies were also included at the later part of this paper to verify this positive relationship between GEO and VR.
Keywords: Canyon Geometry; Morphological Variables; Wind Velocity Ratio (VR); Outdoor Ventilation; High-Rise Residential Estate; Parametric Study; Computational Fluid Dynamics (CFD)