142 research outputs found
Analysis of the structural design process of the adaptive reuse of building structures
No full textIn the field of structural building engineering there is a market shift taking place as a result of the growing number of buildings that are listed as cultural heritage, secularization, the economic situation and the increasing office vacancy rate in Europe and the US. More and more structural engineering firms that were designing and constructing new buildings now move to maintenance and adaptive reuse of existing building structures. But how does this shift influence the way in which engineering firms work? What is the influence of adaptive reuse of existing building structures on the structural design process? Unlike fields like architecture and especially industrial design that have a strong design tradition, in structural engineering until now engineering design has been regarded more as a craft that has to be learned in practice than as science. As a result of this, arguments to answer those questions are hard to find in literature (with a few notable but little cited exceptions such as the paper How designs develop by S.J. Macpherson c.s.[2]). To fill this gap an analysis has been made of the way in which the design process of adaptive reuse projects is supposed to work according to literature and professional associations, and of the way it really works in practice. Grounded theory method is used to generate concepts to explain the way structural designers work in such projects. Preliminary results show that standard descriptions of the engineering design process (generally from abstract to detail as for instance suggested in The Architect’s Handbook by J.A. Demkin c.s.[3]) do not correctly describe the way in which this design process really works. Not only did the redesign process of existing building structures not work as expected by both clients and practitioners; even the structural design process of new building projects can be seen in a different light. It is expected that the results of this research eventually might lead to different contracts between clients and engineering firms in the future.Structural EngineeringCivil Engineering and Geoscience
Analysis of drainage system in Georgetown, Guyana
No full textIn 2015 Georgetown, Guyana suffered from major flooding due to heavy rainfall. The use of a centuries-old agricultural drainage system for the urban drainage of the largest urbanized area of Guyana, poses problems considering flood safety. In 2016 a report was published by a ‘Dutch Risk Reduction Team’ (DRR Team) with recommendations on how to reduce the current flood vulnerability. Based on the recommendations from this DRR report. A team of seven students from the Delft University of Technology, the Netherlands, went to Georgetown and analysed the drainage system in more detail. Several methods were developed in collaboration with local students and experts which can be used to analyse the system. This was done to increase the local capability of knowledge-based decision making on drainage issues in Guyana. This student’s induced project comprises three elements of the urban drainage system: the primary drainage channels, the local (secondary and tertiary) drainage canals, and the outlet structures. The work focussed primarily on the catchment area named South-Ruimveldt.Civil Engineering and GeosciencesHydraulic Engineering / Structural EngineeringMaster project repor
Doorbuiging van schalen door puntlasten
No full textStructural MechanicsStructural EngineeringCivil Engineering and Geoscience
Finding and materializing common subexpressions among queries in a query workload
No full textMost queries in a collection of queries, also called a query workload, to some degree have parts of their intermediate execution steps in common. These intermediate exe- cution steps, also called subexpressions, provide the opportunity to further optimize query workload execution in addition to the already existing query optimization done by the DBMS. A lot of research has been done into this topic however most of that research is either proprietary or just not applicable to big query workloads. In this thesis I developed a simple yet effictive heuristic algorithm to quickly find common subexpressions and materialize them to disk using open source software with results showing a significant increase in performance.Computer Science | Software Technolog
The Safety Level Of Concrete Pile Foundations Under Industrial Monuments
No full textPrefabricated concrete piles have been used for the foundation of bigger buildings for about a century. Often a change in function, an addition (also vertically) or another type of alteration is required, resulting in different loads on the foundation. There are several complicating factors that return regularly in these assessments. The first one is a lack of data. Often drawings are missing or incomplete, e.g. showing only pile head dimensions or maximum calculated load but not the pile length, pile tip shape or material properties. Inspection is hard and only possible for the part directly under the pile head. And a third complication is that in The Netherlands there have only been official codes for piles since 1992. Various calculation and design methods from WWII until 1985 are discussed to see if there is any consistency that might lead to an indication of the load bearing capacity of piles in The Netherlands from that era. It is concluded that design rules for the load bearing capacity of concrete pile foundations in The Netherlands have been inconsistent over time. If the original detailed geotechnical calculations and/or structural drawings cannot be found in archives then the given ultimate loads cannot only not be exceeded; even if the load on a pile is currently less than stated on the technical specifications designers are advised not to increase the load.Applied Mechanic
Structural Design of North Side of Breda Central Station
No full textThe topology of the Breda CS has the image of the whole station complex under one single roof. The architectural design meets the needs for a public transport where large open space can be found in most area. However, the bus terminal on the north side at level 1 has many columns and low ceiling height. This master’s thesis aims to reduce the rows of columns on the bus terminal and creative more open space for the public in a structural way. The north side of Breda CS has the dimension of 180m long, 27.5m wide and 23m high.Design and ConstructionCivil Engineering and Geoscience
Seismic Risk Mitigation in Greece: Translation of Dutch flood risk management practices
No full textSeismic risk in some regions of Greece has increased over the last decades. The reason lies in urban development in earthquake prone regions, combined with a lack of ability or interest to tackle known construction vulnerabilities of buildings. Despite the severity of risk, also confirmed by recent events, homeowners have proven unwilling to mitigate seismic risk, possibly because of their inability to pay and/or unwillingness to invest due to lack of information or awareness. As a result, significant part of the building stock remains unsafe, in comparison with the safety level of the current building code. A way to stimulate seismic risk mitigation is government intervention. Such intervention could consist of a safety plan (retrofit program, mandatory insurance, emergency planning etc.) implemented by government, subsidies, introduction of more stringent building codes, risk communication. Recent developments in Greece regarding seismic safety are mostly aimed at vulnerability and risk evaluation, the publishing of a technical building Code of Interventions, and mapping out a seismic safety plan for Greece. Meanwhile, experts ask for government intervention proposing organisational change and a distribution of roles / liabilities among different clusters. For every scheme of government program, risk estimation is vital to be able to set priorities and decide whether buildings, municipalities, or regions are safe enough. Besides economic risks, risks to life should also be considered. Instruments for quantifying fatality risks are however unavailable at present. A review of the cornerstones of Dutch flood risk management practices, especially in risk estimation and decision-making has shown that fatality risks are considered from a societal perspective and an individual one. The societal risk metric concerns the (exceedance) probabilities of larger numbers of fatalities; the individual risk metric concerns the probability of death of a person at a specific location. In the case of the Netherlands, due to the nature of the flood hazard and protection scheme (public flood defences), the government is strongly involved in flood risk mitigation. Despite differences between the protection schemes for large-scale floods (strengthening dikes rather than protecting buildings) and earthquakes (strengthening buildings), this project proposes the translation (=the act of converting) of aforementioned metrics to the case of seismic risk in Greece. To quantify those metrics for earthquakes requires knowledge of the probabilities of different hazard levels (peak ground accelerations), the extent of damage on buildings given the hazard, and the expected number of fatalities in case of damage given the extent of damage. In this study, societal risk (depicted by FN-curves) and individual risk levels are quantified using exceedance probability function of peak ground acceleration at the site under Seismic Risk Mitigation in Greece Translation of Dutch Flood Risk Management Practices consideration, as well as deterministic transfer functions for damage (vulnerability curves) and losses (mortality curves). Moreover, since economic losses of earthquakes can also be significant, societal economic risk (FL-curve) and individual economic risk are also proposed and quantified. Using recent research results about the vulnerability of buildings, inventory data for social economic characteristics and reasonable assumptions about missing information (like building size); risk can be estimated for existing and retrofitted building stocks of Greek municipalities. After sensitivity analysis of model parameters, two case studies are presented that show the use of the aforementioned risk metrics for different levels of government decision-making. One simulating top level (central government) decision making, setting priorities for retrofit between municipalities, and the second simulating medium level (local government) decision making, setting priorities for a retrofit program between different structural typologies of buildings. The case studies show that the risk metrics and the model to quantify them can be useful tools for deciding which municipality should absorb more resources, whether mitigation is urgent, which mitigation strategy is most efficient, and how alternative retrofit programs influence risk levels. Of course, the model is only a prototype further refinements are advised. There are important benefits from the implementation of the described methodology. Firstly, the decision maker only deals with probabilities and consequences, has a general overview thus he/she may distribute resources and time in a more (cost) effective way. Moreover, human life is distinguished from cost-benefit analysis (no monetization). Events with high numbers of fatalities, which can cause disruption to the whole of the country, as well as disproportional individual exposures, can be targeted directly. Finally, it gives the opportunity to monitor the progress of a safety plan, and is scalable for central and local administration. This study concludes by proposing the application of societal & individual risk metrics (for fatalities and economic loss) to support two levels (central and local) of government decision making concerning seismic risk mitigation in Greece. Furthermore, it provides a prototype model for the quantification of these metrics. Finally, this thesis proposes directions for further research, the most important being research about the costs of alternative retrofit programs, which is necessary for the debate about appropriate (efficient/feasible) societal & individual risk acceptance criteria.Design and Construction ProcessesCivil Engineering and Geoscience
Widget Dashboard
No full textDuring the ten week project the implementation of a Widget Dashboard was made for the company Fenêtre. Fenêtre is a company that provides online solutions like web applications and consultancy. The dashboard displays different existing pages in the form of widgets which are freely movable and resizable by the user of the dashboard and give the user a high level of personalization. The Dashboard is made using the Gridstack framework. This framework provides the functionality to move and resize the widgets. The choice made on using this framework took place in a three week research phase at the start of the project, where multiple different dashboard frameworks and examples were investigated. Gridstack was chosen because it gave the most freedom in implementing the dashboard around the existing features. Other frameworks gave too much of a restriction on implementation. To make sure that an unauthorized user cannot view confidential content the existing authentication of Fenêtre is used to only load widgets that meet the rights of the user. During the development stage of the project, scrum was used to organise the project team. Using the scrum methodology made it easier to recognize the different tasks which needed to be done. However, since the product team consisted of 2 people scrum made things sometimes more tedious than it has to be. During the development phase of the project we have learned a lot about working in an company environment, the importance of a good planning and asking questions early to get a complete overview of what needs to be done during the project.Electrical Engineering, Mathematics and Computer ScienceSoftware Technolog
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