Investigating the impact of occupant response time on computer simulations of the WTC North Tower evacuation

This work explores the impact of response time distributions on high-rise building evacuation. The analysis utilises response times extracted from printed accounts and interviews of evacuees from the WTC North Tower evacuation of 11 September 2001. Evacuation simulations produced using these “real” response time distributions are compared with simulations produced using instant and engineering response time distributions. Results suggest that while typical engineering approximations to the response time distribution may produce reasonable evacuation times for up to 90% of the building population, using this approach may underestimate total evacuation times by as much as 61%. These observations are applicable to situations involving large high-rise buildings in which travel times are generally expected to be greater than response times

Methodologies employed in the collection, retrieval and storage of human factors information derived from first hand accounts of survivors of the WTC disaster of 11 September 2001

This article provides a broad overview of project HEED (High-rise Evacuation Evaluation Database) and the methodologies employed in the collection and storage of first-hand accounts of evacuation experiences derived from face-to-face interviews of evacuees from the World Trade Center (WTC) Twin Towers complex on September 11, 2001. In particular, the article describes the development of the HEED database. This is a flexible research tool which contains qualitative type data in the form of coded evacuee experiences along with the full interview transcripts. The data and information captured and stored in the HEED database is not only unique, but provides a means to address current and emerging issues relating to human factors associated with the evacuation of high-rise buildings

A case for facade integrated solar thermal systems.

This paper explores the potential for façade located solar thermal collectors. Building typologies with limited roof space area are highlighted. A relationship exists between hot water consumption and the solar collector area; hence, a literature review of the hot water consumption of different building typologies is conducted. The review showed that there is a paucity of information on the hot water consumption of buildings, primarily attributed to the difficulty in quantifying it. The hot water consumption is typically describedusing liters per capita per day (Lcd) units, with a broad range of values existing, dependent, primarily on the building's function and location. Asimulation-based study is conducted to size solar thermal systems for different buildings and their associated hot water loads. High solar fractions,for buildings with high levels of hot water consumption, could only be achievedby using significantly largercollector surface areas. As a result, façade located solar thermal collectors are required for certain high-rise buildings that aim to provide for their hot water needs using a considerable portion of solar energy.

Mechanical Properties of Rice Husk Ash (RHA) - High strength Concrete

High strength and high performance concrete are being widely used all over the world. Most of the applications of high strength concrete have been found in high rise buildings, long span bridges etc. The potential of rice husk ash as a cement replacement material is well established .Earlier researches showed an improvement in mechanical properties of high strength concrete with finely ground RHA as a partial cement replacement material. A review of literature urges the need for optimizing the replacement level of cement with RHA for improved mechanical properties at optimum water binder ratio. This paper discusses the mechanical properties of RHA- High strength concrete at optimized conditions

Towards a holistic modelling framework for embodied carbon and waste in the building lifecycle

As the building industry proceeds in the direction of low impact buildings, research attention is being drawn towards the reduction of carbon dioxide emission and waste. Starting from design and construction to operation and demolition, various building materials are used throughout the whole building lifecycle involving significant energy consumption and waste generation. Building Information Modelling (BIM) is emerging as a tool that can support holistic design-decision making for reducing embodied carbon and waste production in the building lifecycle. This study aims to establish a framework for assessing embodied carbon and waste underpinned by BIM technology. On the basis of current research review, the framework is considered to include functional modules for embodied carbon computation. There are a module for waste estimation, a knowledge-base of construction and demolition methods, a repository of building components information, and an inventory of construction materials’ energy and carbon. Through both static 3D model visualisation and dynamic modelling supported by the framework, embodied energy (carbon), waste and associated costs can be analysed in the boundary of cradle-to-gate, construction, operation, and demolition. The proposed holistic modelling framework provides a possibility to analyse embodied carbon and waste from different building lifecycle perspectives including associated costs. It brings together existing segmented embodied carbon and waste estimation into a unified model, so that interactions between various parameters through the different building lifecycle phases can be better understood. Thus, it can improve design-decision support for optimal low impact building development. The applicability of this framework is anticipated being developed and tested on industrial projects in the near future.

Effect of mesh distortion on the accuracy of high order vorticity-velocity CFD approaches

The numerical solution of the incompressible Navier-Stokes equations offers an alternative to experimental analysis of fluid-structure interaction (FSI). We would save a lot of time and effort and help cut back on costs, if we are able to accurately model systems by these numerical solutions. These advantages are even more obvious when considering huge structures like bridges, high rise buildings or even wind turbine blades with diameters as large as 200 meters. The modeling of such processes, however, involves complex multiphysics problems along with complex geometries. This thesis focuses on a novel vorticity-velocity formulation called the Kinematic Laplacian Equation (KLE) to solve the incompressible Navier-stokes equations for such FSI problems. This scheme allows for the implementation of robust adaptive ordinary differential equations (ODE) time integration schemes, allowing us to tackle each problem as a separate module. The current algortihm for the KLE uses an unstructured quadrilateral mesh, formed by dividing each triangle of an unstructured triangular mesh into three quadrilaterals for spatial discretization. This research deals with determining a suitable measure of mesh quality based on the physics of the problems being tackled. This is followed by exploring methods to improve the quality of quadrilateral elements obtained from the triangles and thereby improving the overall mesh quality. A series of numerical experiments were designed and conducted for this purpose and the results obtained were tested on different geometries with varying degrees of mesh density.

Effect of high order interpolation in the stability and efficiency of the time-integration process in vorticity-velocity CFD algorithms

The numerical solution of the incompressible Navier-Stokes Equations offers an effective alternative to the experimental analysis of Fluid-Structure interaction i.e. dynamical coupling between a fluid and a solid which otherwise is very complex, time consuming and very expensive. To have a method which can accurately model these types of mechanical systems by numerical solutions becomes a great option, since these advantages are even more obvious when considering huge structures like bridges, high rise buildings, or even wind turbine blades with diameters as large as 200 meters. The modeling of such processes, however, involves complex multiphysics problems along with complex geometries. This thesis focuses on a novel vorticity-velocity formulation called the KLE to solve the incompressible Navier-stokes equations for such FSI problems. This scheme allows for the implementation of robust adaptive ODE time integration schemes and thus allows us to tackle the various multiphysics problems as separate modules. The current algorithm for KLE employs a structured or unstructured mesh for spatial discretization and it allows the use of a self-adaptive or fixed time step ODE solver while dealing with unsteady problems. This research deals with the analysis of the effects of the Courant-Friedrichs-Lewy (CFL) condition for KLE when applied to unsteady Stoke’s problem. The objective is to conduct a numerical analysis for stability and, hence, for convergence. Our results confirmthat the time step ∆t is constrained by the CFL-like condition ∆t ≤ const. hα, where h denotes the variable that represents spatial discretization.

High life in the sky? Mortality by floor of residence in Switzerland

Living in high-rise buildings could influence the health of residents. Previous studies focused on structural features of high-rise buildings or characteristics of their neighbourhoods, ignoring differences within buildings in socio-economic position or health outcomes. We examined mortality by floor of residence in the Swiss National Cohort, a longitudinal study based on the linkage of December 2000 census with mortality and emigration records 2001-2008. Analyses were based on 1.5 million people living in buildings with four or more floors and 142,390 deaths recorded during 11.4 million person-years of follow-up. Cox models were adjusted for age, sex, civil status, nationality, language, religion, education, professional status, type of household and crowding. The rent per m² increased with higher floors and the number of persons per room decreased. Mortality rates decreased with increasing floors: hazard ratios comparing the ground floor with the eighth floor and above were 1.22 [95% confidence interval (CI) 1.15-1.28] for all causes, 1.40 (95% CI 1.11-1.77) for respiratory diseases, 1.35 (95% CI 1.22-1.49) for cardiovascular diseases and 1.22 (95% CI 0.99-1.50) for lung cancer, but 0.41 (95% CI 0.17-0.98) for suicide by jumping from a high place. There was no association with suicide by any means (hazard ratio 0.81; 95% CI 0.57-1.15). We conclude that in Switzerland all-cause and cause-specific mortality varies across floors of residence among people living in high-rise buildings. Gradients in mortality suggest that floor of residence captures residual socioeconomic stratification and is likely to be mediated by behavioural (e.g. physical activity), and environmental exposures, and access to a method of suicide.

Seismic Risk Scenarios in Puerto Principe (Haiti). A Tool for Reconstruction and Emergency Planning

The 12 January 2010, an earthquake hit the city of Port-au-Prince, capital of Haiti. The earthquake reached a magnitude Mw 7.0 and the epicenter was located near the town of Léogâne, approximately 25 km west of the capital. The earthquake occurred in the boundary region separating the Caribbean plate and the North American plate. This plate boundary is dominated by left-lateral strike slip motion and compression, and accommodates about 20 mm/y slip, with the Caribbean plate moving eastward with respect to the North American plate (DeMets et al., 2000). Initially the location and focal mechanism of the earthquake seemed to involve straightforward accommodation of oblique relative motion between the Caribbean and North American plates along the Enriquillo-Plantain Garden fault system (EPGFZ), however Hayes et al., (2010) combined seismological observations, geologic field data and space geodetic measurements to show that, instead, the rupture process involved slip on multiple faults. Besides, the authors showed that remaining shallow shear strain will be released in future surface-rupturing earthquakes on the EPGFZ. In December 2010, a Spanish cooperation project financed by the Politechnical University of Madrid started with a clear objective: Evaluation of seismic hazard and risk in Haiti and its application to the seismic design, urban planning, emergency and resource management. One of the tasks of the project was devoted to vulnerability assessment of the current building stock and the estimation of seismic risk scenarios. The study was carried out by following the capacity spectrum method as implemented in the software SELENA (Molina et al., 2010). The method requires a detailed classification of the building stock in predominant building typologies (according to the materials in the structure and walls, number of stories and age of construction) and the use of the building (residential, commercial, etc.). Later, the knowledge of the soil characteristics of the city and the simulation of a scenario earthquake will provide the seismic risk scenarios (damaged buildings). The initial results of the study show that one of the highest sources of uncertainties comes from the difficulty of achieving a precise building typologies classification due to the craft construction without any regulations. Also it is observed that although the occurrence of big earthquakes usually helps to decrease the vulnerability of the cities due to the collapse of low quality buildings and the reconstruction of seismically designed buildings, in the case of Port-au-Prince the seismic risk in most of the districts remains high, showing very vulnerable areas. Therefore the local authorities have to drive their efforts towards the quality control of the new buildings, the reinforcement of the existing building stock, the establishment of seismic normatives and the development of emergency planning also through the education of the population.

Wind tunnel analysis on the influence of cantilever parapets on the wind loads on curved roofs

Different methods to reduce the high suction caused by conical vortices have been reported in the literature: vertical parapets, either solids or porous, placed at the roof edges being the most analysed configuration. Another method for alleviating the high suction peaks due to conical vortices is to round the roof edges. Very recently, the use of some non-standard parapet configurations, like cantilever parapets, has been suggested. In this paper, its efficiency to reduce suction loads on curved roofs is experimentally checked by testing the pressure distribution on the curved roof of a low-rise building model in a wind tunnel. Very high suction loads have been measured on this model, the magnitude of these high suction loads being significantly decreased when cantilever...

Luciano Kulczewski, arquitecto: Eclecticismo y procesos modernizadores en el Chile de la primera mitad del siglo XX

Esta investigación tiene por fin poner en valor la obra del arquitecto chileno Luciano Kulczewski, profesional que cumplió un rol clave y distintivo en la primera mitad del siglo XX, considerado como un período crucial para el desarrollo de la arquitectura nacional, ya que es el momento en que se produce el advenimiento de la modernidad en el país. Si bien su figura goza de un gran reconocimiento, solamente una parte de su obra es (re)conocida por la historiografía nacional. Su labor en el libre ejercicio de la profesión, como asimismo los distintos cargos administrativos y políticos que desempeñó en su vida, hacían suponer un corpus más amplio, como finalmente se pudo constatar en este estudio. El amplio catastro documentado permitió fehacientemente identificar el rol y el significado que esta obra cumpliera en la transición que hizo posible dejar atrás los valores impuesto por el Academicismo, para incorporar los procesos de modernización en los distintos ámbitos de la arquitectura. Por tanto, el quehacer de Kulczewski se reveló como ejemplar y paradigmático. Una de las ilustraciones más elocuentes a este respecto fue la precursora realización de edificios en altura para uso residencial. Esta tipología lo obligó a trabajar con nuevos materiales y técnicas constructivas, junto a la necesidad de introducir las modernas tecnologías que estos portentos arquitectónicos requerían para su funcionamiento, como era el uso de ascensores y los sistemas de calefacción centralizada. El estudio del contexto urbano de sus obras permitió dar cuenta también de los procesos que estaban convirtiendo a las principales ciudades del país en urbes ‘modernas’. En este ámbito, destaca la nueva concepción urbanística que llegaba vinculada a los barrios-jardín, que contrariamente a lo establecido por el urbanismo tradicional, implicó inéditas maneras de articular la ciudad y el empleo de nuevas tipologías residenciales. Estas concepciones de ciudad encontraron eco principalmente en las urbanizaciones que se estaban realizando en las nuevas comunas de la capital, contexto elegido por el arquitecto para llevar a cabo algunos innovadores conjuntos habitacionales, hoy considerados modélicos, y que estaban destinados a un nuevo estrato social empoderado y demandante: la clase media. Su particular preocupación por las cuestiones sociales, las que entraron en crisis con el devenir del siglo XX, lo llevaron a desarrollar una activa vida política, que culminó con un importante puesto administrativo en el primer Gobierno Radical que tuvo lugar en el país. Desde esa posición, pudo gestionar y dar solución apropiada a la urgente necesidad de viviendas obreras que requería el país, creando los primeros edificios colectivos destinados a este grupo social. Esto a la vez supuso un acercamiento más sustancial a las nuevas propuestas vinculadas al Movimiento Moderno. En conclusión, su quehacer hizo eco de los estilos vanguardistas y modernos que arribaron provenientes de Europa, pero reconociendo las realidades propias del país, de tal forma que la apropiación, y no la reproducción, fue su sello. En este proceso de adecuación al medio local, los modelos foráneos se desprenderán de muchas de sus principios rectores originales, lo que sumado a la impronta de un imaginario propio y original, convierten a sus creaciones en un caso singular en el contexto del la arquitectura chilena. ABSTRACT This research aims to add value to the work of Chilean architect Luciano Kulczewski, a professional who accomplished a key and distinctive role in the first half of the twentieth century, which is considered as a crucial period for the development of the Chilean architecture, since it corresponds to the arrive of Modernity in this country. While his figure is widely recognized, only a portion of his oeuvre is known (or acknowledged) by national historiography. Because of his work as a freelance professional and another administrative and political position he held in his life, it is possible to assume a larger corpus, as it was finally confirmed by this study. The copious documented cadastre allowed convincingly to identify the role and significance that this work fulfilled in the transition that made possible leaving behind the values imposed by Academicism, and thus to incorporate the modernization processes in the different fields of architecture. Therefore, the work of Kulczewski revealed itself as exemplary and paradigmatic. One of the most eloquent illustrations to this regard was the pioneering construction of high-rise buildings with a residential purpose. This typology drove him to work with new materials and constructive techniques, alongside with the need of introducing new modern technologies required by these architectonical advances for its operations, like the use of elevators and central heating systems. The study of the urban context of his work allowed also accounting the processes the major cities of the country went through in order to become 'modern' cities. In this context, it stands out the new urban conception linked to the idea of garden city, which was contrary to the practices of the traditional urbanism, and that implied new ways of articulating the city and that the use of new residential typologies. These urban notions were mainly echoed in the urbanizations that were made in the new districts of the city, scenario chosen by the architect for the concretion of innovative housing projects, nowadays thought as paradigmatic, and that were oriented for a new empowered and demanding social group: the middle class. His particular concern for social issues, which ones came into crisis with the arrival of the twentieth century, led him to take an active political role, culminating with an important administrative position in the first Radical Government that took place in the country. From that position, he could manage and provide adequate solutions to the urgent worker’s housing needs that required the country, creating the first collective buildings for this social group. This supposed a more substantial approach to new proposals of the Modern Movement. To conclude, his oeuvre was influenced by the avant-garde and modern styles that arrived from Europe, but with the proper adjustments to the local requirements, so that it is possible to say that appropriation more than reproduction was his hallmark. In this process, these features were transformed in order to get more flexibility for their adaptation to the Chilean needs that added to a personal and peculiar imaginary, which transformed his works into a unique case in the national architecture history.

The appraisal and management of multi-storey dwelling blocks using large concrete panel systems

This exploratory study is concerned with the integrated appraisal of multi-storey dwelling blocks which incorporate large concrete panel systems (LPS). The first step was to look at U.K. multi-storey dwelling stock in general, and under the management of Birmingham City Council in particular. The information has been taken from the databases of three departments in the City of Birmingham, and rearranged in a new database using a suite of PC software called `PROXIMA' for clarity and analysis. One hundred of their stock were built large concrete panel system. Thirteen LPS blocks were chosen for the purpose of this study as case-studies depending mainly on the height and age factors of the block. A new integrated appraisal technique has been created for the LPS dwelling blocks, which takes into account the most physical and social factors affecting the condition and acceptability of these blocks. This appraisal technique is built up in a hierarchical form moving from the general approach to particular elements (a tree model). It comprises two main approaches; physical and social. In the physical approach, the building is viewed as a series of manageable elements and sub-elements to cover every single physical or environmental factor of the block, in which the condition of the block is analysed. A quality score system has been developed which depends mainly on the qualitative and quantitative conditions of each category in the appraisal tree model, and leads to physical ranking order of the study blocks. In the social appraisal approach, the residents' satisfaction and attitude toward their multi-storey dwelling block was analysed in relation to: a. biographical and housing related characteristics; and b. social, physical and environmental factors associated with this sort of dwelling, block and estate in general.The random sample consisted of 268 residents living in the 13 case study blocks. Data collected was analysed using frequency counts, percentages, means, standard deviations, Kendall's tue, r-correlation coefficients, t-test, analysis of variance (ANOVA) and multiple regression analysis. The analysis showed a marginally positive satisfaction and attitude towards living in the block. The five most significant factors associated with the residents' satisfaction and attitude in descending order were: the estate, in general; the service categories in the block, including heating system and lift services; vandalism; the neighbours; and the security system of the block. An important attribute of this method, is that it is relatively inexpensive to implement, especially when compared to alternatives adopted by some local authorities and the BRE. It is designed to save time, money and effort, to aid decision making, and to provide ranked priority to the multi-storey dwelling stock, in addition to many other advantages. A series of solution options to the problems of the block was sought for selection and testing before implementation. The traditional solutions have usually resulted in either demolition or costly physical maintenance and social improvement of the blocks. However, a new solution has now emerged, which is particularly suited to structurally sound units. The solution of `re-cycling' might incorporate the reuse of an entire block or part of it, by removing panels, slabs and so forth from the upper floors in order to reconstruct them as low-rise accommodations.

Cidade compacta

Dissertação de Mestrado para a obtenção do grau de Mestre em Arquitectura, apresentada na Faculdade de Arquitectura da Universidade Técnica de Lisboa.

The application of Lob in the UAE: a case study of a housing project

Line of Balance (LOB) scheduling technique is a significant technique that plays a vital role in repetitive construction projects. It became more demanding in the construction industry due to the construction of mega repetitive projects e.g. housing schemes, high rise buildings, railways and highways, etc. This paper aims to evaluate the real application of LOB in repetitive housing projects in the UAE which could fill the gap as there is lack of similar empirical studies in the Middle East. The paper firstly presents a concise literature review on the application and limitation of LOB comparing to CPM in repetitive projects. Then, a case study of 275 villas housing project in the UAE is demonstrated and analysed, where LOB technique was used and monitored throughout the lifecycle of the project. The findings point out significant controlling benefits of using LOB comparing with CPM in the project and address some limitations hindering the efficient use of LOB in the UAE.

Low energy strategies for high-rise apartments in Hong Kong

High-rise apartments provide 90% of the living requirements in Hong Kong. (Lam 1995) The construction material of these buildings is primarily concrete for both external wall and interior partitions with little or no thermal insulation. Due to the hot and humid climatic conditions and expectations of an ever-increasing standard of living, occupants are installing air-conditioning systems into their apartments. This has generated a tremendous electrical demand as well as an environmental (greenhouse gas emission) concern. This paper explores some of the low energy strategies that can be applied to this building typology. The effect of seven energy-saving strategies ranging from thermal insulation to different window systems and shading devices was investigated. The results show that there is the potential to reduce the annual cooling energy consumption and peak cooling load by 40% and 33% respectively.