Numerical analyses in the design of umbrella arch systems

Due to advances in numerical modelling, it is possible to capture complex support-ground interaction intwo dimensions and three dimensions for mechanical analysis of complex tunnel support systems,although such analysis may still be too complex for routine design calculations. One such system is theforepole element, installed within the umbrella arch temporary support system for tunnels, whichwarrants such support measures. A review of engineering literature illustrates that a lack of designstandards exists regarding the use of forepole elements. Therefore, when designing such support, designersmust employ complex numerical models combined with engineering judgement. With referenceto past developments by others and new investigations conducted by the authors on the Driskos tunnelin Greece and the Istanbul metro, this paper illustrates how advanced numerical modelling tools canfacilitate understanding of the influences of design parameters associated with the use of forepole elements.In addition, this paper highlights the complexity of the ground-support interaction whensimulated with two-dimensional （2D） finite element software using a homogenous reinforced region,and three-dimensional （3D） finite difference software using structural elements. This paper further illustratessequential optimisation of two design parameters （spacing and overlap） using numericalmodelling. With regard to capturing system behaviour in the region between forepoles for the purpose ofdimensioning spacing, this paper employs three distinctive advanced numerical models： particle codes,continuous finite element models with joint set and Voronoi blocks. Finally, to capture the behaviour/failure ahead of the tunnel face （overlap parameter）, 2D axisymmetric models are employed. Finally,conclusions of 2D and 3D numerical assessment on the Driskos tunnel are drawn. The data enriched casestudy is examined to determine an optimum design, based on the proposed optimisation of designparameters, of forepole elements related to the si     

A case study in early urban design: Toronto, 1966–1978

ABSTRACT

This is a study in the practice of postwar urban design in Toronto, Canada, based on archival documents and interviews with participants. The narrative begins with the hiring of one British-trained architect/urban designer, Raymond Spaxman, by the City of Toronto Planning Board in 1966. Spaxman then set up a new division of staff that he filled with five or six other architect/urban designers of various national and institutional origins. The study describes the work carried out by these urban designers, identifies the principle themes apparent in it, and relates this to published literature on the founding principles of postwar urban design. In most ways, the study's findings fit the current understanding of the early discipline – concern for pedestrians, sympathy for historical preservation – but in others not – it was different from but not antagonistic towards planning. The findings are then considered as an example of the international transfer of postwar planning ideas. The process of idea transfer in this case looks to have been more chaotic, and less definable, than existing paradigms suggest, but this might have been fairly common in second-rank, immigrant-receiving cities.     

Risk analysis in fixed-price design–build construction projects

Construction projects are being tendered and implemented under different contract systems and payment methods. Design–build has been a popular contract system in recent years. It provides various advantages through entailing the contractor carrying out and being responsible for not only construction but also the design of the work. However, design–build turns out to be a risky system for both owners and contractors unless the risks are identified, analyzed and managed throughout the tender preparation and project execution stages. In this context, this study aims to present a literature survey on the issues of risk, risk management/analysis and the design–build contract system, to propose a schedule and cost risk analysis model, and to show the applicability of these models in scheduling and cost estimation of a fixed-price design–build construction project through a case study.     

Ecological Networks: connecting environmental, economic and social systems?

Ecological networks for different spatial scales (international to sub-regional) are being defined and realized throughout Europe. Historically they have been focused on nature conservation, but they may offer a mechanism whereby a holistic, integrated and long-term approach to regional and sub-regional sustainable development can be promoted. Economic, social and environmental factors operate at different spatial and temporal scales, presenting challenges to those wishing to develop an ecological network. A case study based on the development of an ecological network for Cheshire, a sub-region of the European Region-North West (UK), demonstrates how environmental issues might be integrated with social and economic drivers of change. A framework for an ecological network is proposed by combining an outline model of the socio-ecological system within Cheshire with a checklist that can be used to assess the sustainable management of a landscape.     

Ecological Networks: Connecting environmental,economic and social systems?

Ecological networks for different spatial scales (international to sub-regional) are being defined and realized throughout Europe. Historically they have been focused on nature conservation, but they may offer a mechanism whereby a holistic, integrated and long-term approach to regional and sub-regional sustainable development can be promoted. Economic, social and environmental factors operate at different spatial and temporal scales, presenting challenges to those wishing to develop an ecological network. A case study based on the development of an ecological network for Cheshire, a sub-region of the European Region-North West (UK), demonstrates how environmental issues might be integrated with social and economic drivers of change. A framework for an ecological network is proposed by combining an outline model of the socio-ecological system within Cheshire with a checklist that can be used to assess the sustainable management of a landscape.     

Indirect evaporative cooling potential in air–water systems in temperate climates

Recent developments have prompted a review of evaporative cooling technology as an effective means of cooling modern deep plan buildings. Prominent among these developments is the success of high temperature sensible cooling systems, particularly, chilled ceilings, which require a supply of cooling water at 14–18 °C. Crucial to the success of evaporative cooling technology, as a significant means of cooling in modern applications, is the ability to generate cooling water, in an indirect circuit, at a temperature which closely approaches the ambient adiabatic saturation temperature (AST) or wet bulb temperature (WBT). Recent experimental research has demonstrated that it is technically viable to generate such cooling water at a temperature of 3 K above the ambient AST.While the frequency of ambient AST occurrence can be obtained from meteorological sources, there is little in-depth analysis of the potential for this form of cooling water generation, based on the approach temperatures which have now been shown to be viable. The decision to use an evaporative cooling system depends largely on an assessment, in-depth, of net energy saved against capital expended. Such an assessment requires detailed data on the availability of cooling water, generated by evaporation, for each location. This paper quantifies evaporative cooling availability in-depth for a northern and southern European city, Dublin and Milan and suggests a method of analysing such data for any world wide location, for which suitable meteorological records are available. The paper, incorporates recent experimental research findings and bases the availability analysis on meteorological test reference weather year data.The results of this research confirm a major potential for the generation of cooling water by evaporative means, which can be used to provide effective cooling of deep plan buildings by means of contemporary water based sensible cooling systems, such as fan coil systems, radiant chilled ceiling panels and ceiling cooling convectors (chilled beams). While the technique offers most potential in locations with a northern European temperate climate, it has significant potential to contribute to cooling in some southern European cities, during the non-summer months and also at other times, particularly where load shaving techniques are incorporated.     

An approach for optimizing pavement design–redesign parameters in PPP projects

Modeling the elasticity modulus of unbound granular pavement materials has attracted significant research interest because of its importance in pavement design particularly in PPP/BOT projects. These efforts have been hampered by three factors: (i) inability to capture the correlations between the asphalt and granular layers and the subgrade, (ii) inadequate modeling of the effects of external factors on the elasticity modulus of unbound materials, and (iii) widespread use of linear statistical relationships to model a complex and non-linear phenomenon. In this paper genetically optimized neural networks and falling weight deflectometer (FWD) back-analysis results from a newly constructed BOT project in Athens, Greece, are employed in order to evaluate pavement section design parameters. It is shown that parameter values adopted during design do not co-inside with those observed from the back-analysis studies. Further, the results indicate that the relative estimation error for the modulus of elasticity of the unbound material does not exceed 25%, while the correlation between actual and predicted values is 86%, both suggesting that the proposed approach models the physical phenomenon adequately, a finding with important practical implications particularly in PPP projects.     

Beyond the romantic and naı¨ve: the search for a complex ecological aesthetic design language for landscape architecture in New Zealand

Landscape design is an expression and repository of cultural values and beliefs, and in Aotearoa, New Zealand, the designed landscape faces particular challenges. Globalization is seen as a potential threat to landscape identity, which is even more significant for a country which has built its economy and self-image from its unique natural landscape. The potential for resistance is limited by the small size and youth of the profession of landscape architecture in New Zealand. While traditions of farming and gardening extend back to early European settlement in the mid nineteenth century, and beyond to indigenous Maori practices of land modification, professional landscape design is a relatively recent development (the first tertiary course in landscape architecture began at Lincoln College (now Lincoln University) in 1969). Landscape design in New Zealand draws its vocabulary from the power of the country's natural heritage landscapes, convinced that a naturalistic aesthetic exclusively represents environmental health. Some of the core values of New Zealand society are, however, overlooked by designers. The need to develop a critically informed design language which includes the farming landscape along with the natural one is argued. The invention of such a language, referred to as a complex ecological aesthetic, is seen as a potential source of design expression that is invigorated by the tension between mechanistic and natural landscape aesthetics. It therefore has the potential to promote environmental health, while being regionally grounded, and can help face the challenges that globilization poses to the landscape.     

Standing on ye shoulders of giants: promoting a social systems engineering education using ICE president addresses (1820–2014)

Given the paucity of engineering history presently taught on civil engineering programmes, the purpose of this paper is to promote the role of historical testimonies for the delivery of an enhanced, contemporary and social system’s educational experience. Drawing on the addresses of the presidents of the Institution of Civil Engineers (ICE) (1820–2014) as a source of inspiration and motivation, civil engineering students (n?=?428) were required to select and read six inaugural addresses of former ICE presidents and use these as a catalyst for writing their own ‘ICE presidential address’ while keeping an eye forwards to the year 2050. The results reveal that the ICE presidential addresses help introduce undergraduates to the real and ‘human’ world of civil engineering and provide the students with a ‘social’, as opposed to a scientific, understanding of their profession. Exploring and exploiting the substantial depository of knowledge, values, wisdom and social context of ICE presidential addresses are both innovative and novel and worthy of adoption and adaptation by other academies seeking to prepare civil engineering undergraduates as global citizens.     

Cost–benefit analysis for optimal distributed generation placement in distribution systems

This paper presents an optimisation method to determine optimal allocations of distributed generation (DGs) and capacitors based on maximisation of a profit/worth analysis approach. The optimal locations and sizes of DGs and capacitors have been determined by minimising the power distribution loss. This method considers various technical and economic factors such as line losses, sizes of DGs and capacitors at optimal locations, investment costs, operating costs and maintenance costs of DG and capacitor to achieve the objective for a predetermined number. The electricity market price of grid power has been considered to recover initial investment in a specified time period. The improvement in the voltage profile of the system has also been considered in this work. The particle swarm optimisation technique has been used to solve the optimal placement of DGs and capacitors to maximise the profit. The proposed technique is tested on 33-bus and 69-bus test systems.     

Extension planning and the historic city: civic design strategies in the 1908–9 Copenhagen international competition

In shedding light on the 1908–9 competition for Greater Copenhagen this article examines the contest as an instrument for the accumulation and transmission of planning know‐how, ideas and innovations in relation to the development of town planning theory and practice in the Nordic Countries. Plans are considered as both technical and cultural graphics marks reflecting alternative and possibly contradictory images of the greater city or city of the future. The discussion focuses on the relationship between urban design's twin polarities: urban transformation and creation on the one hand; concern for conservation and urban continuity on the other. After considering the competition's international dimension, the article explores the civic art strand of design in northern Europe before 1914 and the idea of the historic city by investigating the conservation movement that flourished in Copenhagen when there were rapid changes in the physical fabric. The article, based on archive materials, analyses of awarded and non‐awarded entries alike, illustrates how architects, engineers and surveyors combined their design of the city's extensions with conservation schemes for both peripheries and centre. It is suggested that, at a time when Nordic municipal authorities were pressing for comprehensive town planning, planners strove to provide ways of protecting the existing built environment. This involved not only safeguarding an emerging ‘historic city’ in contrast to the new extensions, but also proposals for maintaining urban continuity in the peripheries.     

Plug and play type joints in steel and steel–concrete composite constructions: Development guide and design considerations

Traditionally, for countries in Western Europe, joints in steel frame structures are realised using bolts and welds. In the workshop, the components are made using welding end plates and attachments and drilling of the bolt holes. On site, these structural components are connected together using bolts and nuts. The activities on site mean a large physical effort of the steel construction workers who are not free from danger. Measures needed to ease the work and to make it safer for workers are increasingly expensive. There is a need to develop the so-called ‘plug and play’ connections which can be realised using remotely controlled techniques. The development of plug and play type joints is not only important to ease the work on site, but it can also reduce overall costs of the construction if the joint characteristics are taken into account at the design stage. Of the total costs of a steel structure, 50% of that amount is related to the joints whereas almost 90% of the total costs are already decided upon in the construction detailing phase. Optimisation in weight will not result in an optimal cost-efficient structure. Even semi-rigid and partial strength joints that result after the erection phase could lead to cost reduction. Some considerations are given to optimise the joint with respect to overall structural behaviour from a technical and economical point of view. Fast and safe construction methods with plug and play joints are required for the future. Structures need to be designed such that they are fit to be demounted and rebuilt easily. For these types of joints no specific design rules are available in Eurocode 3, Part 1.8: ‘Design of joints’ or in chapter 9 of Eurocode 4, Part 1.1: ‘Composite joints’. This article describes the basis of design for these joints.     

Politics,planning and the protection of nature: Political abuse of early ecological ideas in Germany, 1933–45

This paper has three objectives. First, it illustrates how the theme of rationality, so important for a country's artistic culture and for studies in the positive sciences, is present both in modern Italy and the field of town planning. Second, it examines the ‘limits’ of town planning: a sort of set of ‘commandments’ which establishment culture has formulated in order to test and institutionalize planning projects. Third, it attempts to demonstrate how one of the peculiar and conditioning features of town planning in Italy is the importance attributed to history (the history of the city, the history of planning schemes and procedures) in justifying decisions which result in urban transformation.     

Regulatory changes to Portugal's social tariffs: Carrying water in a sieve?

In Portugal, social tariffs have been used since 2009 to promote universal access and affordability of water services, reducing the burden of vulnerable consumers' water charges.The adoption of social tariffs by the Portuguese water services providers and the recent regulatory changes to the social tariff regime are analyzed. The main conclusion is that the existing differences in terms of affordability across municipalities might persist and this may also jeopardize social sustainability and territorial cohesion.     

The impact of biophilic design in Maggie’s Centres: A meta-synthesis analysis

This paper presents a meta-synthesis conducted to identify, compare and synthesize published qualitative data related to the Maggie's Centres, as a paradigmatic architectural example in the provision of non-institutional cancer support. These centres are internationally renowned for their unique architecture, where the careful design of indoors and outdoors spaces plays a critical role in their agenda for supporting care. Previous research has thoroughly analysed this approach to therapeutic environments, not only confirming the importance of designed space as originally conceived in Maggie's philosophy but also identifying precise supporting effects associated with specific elements within their design. This paper aims to provide a new reading of Maggie's contribution to cancer support by offering an examination of all these data through the lens of biophilia, which clarifies the impact of design decisions connected to nature on cancer patients' lives. The analytic process included a systematic search strategy, extraction and classification of salient concepts using an open-coding approach, and lastly an interpretive evaluation. The systematically selected data helped to identify and rank the biophilic design parameters that appear the most critical for promoting and supporting human health and wellbeing in non-clinical therapeutic environments, from the user's perspective. It also provided a compilation of distinctive design interventions related to biophilic parameters, which provides benchmark information for future research and design guidance in these environments.     

A human-scaled GIS: measuring and visualizing social interaction in Barcelona’s Superilles

Social interaction is a key component of urban sustainability, but its spatial measurement is difficult using existing off-site GIS data. This paper reports on a new method of measuring social interaction using a combination of mobile technology and parametric software, which was tested on two of Barcelona’s new semi-pedestrian superilles. The research is introduced within a theoretical framework for social interaction and cohesion adapted from a broader index of sustainability. It shows how on-site data collection can be used to measure the capacity of urban spaces to support social interaction. It is argued that the combination of mobile technologies, GIS data, and predetermined indicators of the capacity of spaces to support positive human experiences offers an important complement to more traditional methods of recording and measuring the qualities of urban spaces.     

Work–life fit: identification of demand and resource typologies within a systems framework*

Work–life fit occurs when people have the resources required to meet demands such that role performance (both at work and in non-work life domains) is effective. Interviews were conducted with 59 construction workers based in Melbourne, Australia to explore how demands and resources were experienced. Using a systems framework, data were analysed using thematic analysis. Results identified two demand typologies associated with demand-to-demand interaction. Demands operating as ‘influencers’ have a major impact on the conditions of the interdependent demand, while demands operating as ‘creators’ generate a new demand and shape the conditions of that demand. One resource typology related to resource–demand interaction was identified. ‘Enabling resources’ enable an individual to manage multiple demands across multiple domains, and may also enable an individual to manage multiple demands within a single domain. A new conceptual contribution is made to an area in which theory is under-developed, by adopting a systems approach to understanding the dynamic interactions between demands and resources. A lack of fit is damaging for the individual; therefore, it is useful to know that demands and resources are interdependent and these interdependencies will vary according to individuals. Using a systems approach to understanding demands and resources will be helpful to organizations seeking to support workers to achieve optimal work–life fit.     

Path Dependence in Financing Urban Infrastructure Development in China: 1949–2016

In the past few decades, urban infrastructures in China have seen an enormous upgrade, and due to large-scale urbanization many more investments are due in the coming years. In order to supplement public funding, Public Private Partnerships (PPP) and municipal bonds have recently grown popular in China. The introduction of this new policy does not occur in a void but should be understood as the path-dependent consequence of a historical evolution of funding arrangements for urban development. How have Chinese governments traditionally arranged financing for these extensive investments and how has the emphasis in funding sources shifted over time? We argue that the evolution of urban development financing has gone through three phases (planned economy, reform and pilot, and socialist market economy), each with different emphasis in financial sources. Our analysis demonstrates how weaknesses in earlier phases present challenges that new solutions in later phases are aimed to address.