| 1. |
- Sundell, Jonas, 1984, et al.
(författare)
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Comprehensive risk assessment of groundwater drawdown induced subsidence
- 2019
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Ingår i: Stochastic Environmental Research and Risk Assessment. - : Springer Science and Business Media LLC. - 1436-3240 .- 1436-3259. ; 33:2, s. 427-449
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Tidskriftsartikel (refereegranskat)abstract
- © 2019, The Author(s). We present a method for risk assessment of groundwater drawdown induced land subsidence when planning for sub-surface infrastructure. Since groundwater drawdown and related subsidence can occur at large distances from the points of inflow, the large spatial extent often implies heterogeneous geological conditions that cannot be described in complete detail. This calls for estimation of uncertainties in all components of the cause-effect chain with probabilistic methods. In this study, we couple four probabilistic methods into a comprehensive model for economic risk quantification: a geostatistical soil-stratification model, an inverse calibrated groundwater model, an elasto-plastic subsidence model, and a model describing the resulting damages and costs on individual buildings and constructions. Groundwater head measurements, hydraulic tests, statistical analyses of stratification and soil properties and an inventory of buildings are inputs to the models. In the coupled method, different design alternatives for risk reduction measures are evaluated. Integration of probabilities and damage costs result in an economic risk estimate for each alternative. Compared with the risk for a reference alternative, the best prior alternative is identified as the alternative with the highest expected net benefit. The results include spatial probabilistic risk estimates for each alternative where areas with significant risk are distinguished from low-risk areas. The efficiency and usefulness of this modelling approach as a tool for communication to stakeholders, decision support for prioritization of risk reducing measures, and identification of the need for further investigations and monitoring are demonstrated with a case study of a planned railway tunnel in Varberg, Sweden.
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| 2. |
- Sundell, Jonas, 1984, et al.
(författare)
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Economic valuation of hydrogeological information when managing groundwater drawdown
- 2019
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Ingår i: Hydrogeology Journal. - : Springer Science and Business Media LLC. - 1431-2174 .- 1435-0157. ; 27:4, s. 1111-1130
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Tidskriftsartikel (refereegranskat)abstract
- © 2019, The Author(s). A procedure is presented for valuation of information analysis (VOIA) to determine the need for additional information when assessing the effect of several design alternatives to manage future disturbances in hydrogeological systems. When planning for groundwater extraction and drawdown in areas where risks—such as land subsidence, wells running dry and drainage of streams and wetlands—are present, the need for risk-reducing safety measures must be carefully evaluated and managed. The heterogeneity of the subsurface calls for an assessment of trade-offs between the benefits of additional information to reduce the risk of erroneous decisions and the cost of collecting this information. A method is suggested that combines existing procedures for inverse probabilistic groundwater modelling with a novel method for VOIA. The method results in (1) a prior analysis where uncertainties regarding the efficiency of safety measures are estimated, and (2) a pre-posterior analysis, where the benefits of expected uncertainty reduction deriving from additional information are compared with the costs for obtaining this information. In comparison with existing approaches for VOIA, the method can assess multiple design alternatives, use hydrogeological parameters as proxies for failure, and produce spatially distributed VOIA maps. The method is demonstrated for a case study of a planned tunnel in Stockholm, Sweden, where additional investigations produce a low number of benefits as a result of low failure rates for the studied alternatives and a cause-effect chain where the resulting failure probability is more dependent on interactions within the whole system rather than on specific features.
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| 3. |
- Hagbert, Pernilla, et al.
(författare)
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Paradoxes and possibilities for a 'green' housing sector : A swedish case
- 2013
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Ingår i: Sustainability. - : MDPI. - 2071-1050. ; 5:5, s. 2018-2035
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Tidskriftsartikel (refereegranskat)abstract
- As global and local visions for sustainable living environments are increasingly supported by policies and concrete practices in construction, the building and housing sector is seeking to mitigate its environmental impact as well as assume a greater social responsibility. The overarching policy objectives set to concretize what a sustainable housing development entails, however, tend to rely on equivocal terminology, allowing a varied interpretation by key industry practitioners. Though in line with an ecological modernization paradigm in policy, the promotion of a market-driven environmentalism in housing faces multiple challenges as varying interests and perspectives collide. Supported by empirical findings of a semi-structured interview study conducted with housing developers in a new =green' urban district in Göteborg, Sweden, theoretical frameworks surrounding the paradoxical path towards a sustainable housing development are presented. Inconsistencies between outspoken ambitions; social dimensions; and the framing of efficiency in new housing are discussed. Possibilities for the housing sector are given in the recognition of new forms of development, where a systemic perspective is required in the alignment between how industry, policy and the market perceives housing development and what is actually sustainable.
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| 4. |
- Karim, Ali Naman, 1992, et al.
(författare)
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Aerogelbaserad puts- Superisolering för framtiden
- 2020
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Ingår i: Husbyggaren. ; :6, s. 8-11
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- I ett forskningsprojekt på Chalmers studeras en aerogelbaserad puts med mycket bra isolerande egenskaper. Förhoppningen är att användningen av den så kallade superisolerande putsen ska bidra till att minska byggsektorns energianvändning, både för existerande och nya byggnader. Superisolerande puts kan, förutom att spara energi, dessutom resultera i funktionella väggar med mindre tjocklek. Detta bidrar i sin tur till att öka mängden uthyrningsbar golvyta inomhus, yta som annars skulle tagits upp av väggens isolering. I denna artikel vill vi informera om vad vi planerar att göra i projektet och berätta om den superisolerande putsens egenskaper.
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| 5. |
- Mathern, Alexandre, 1986, et al.
(författare)
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Lessons learned from the construction, inspection, and defect assessment of reinforced concrete foundations for wind turbines
- 2022
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Ingår i: Applied Sciences (Switzerland). - : MDPI AG. - 2076-3417. ; 12:3
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Tidskriftsartikel (refereegranskat)abstract
- Foundations of wind turbines are subject to challenging conditions during their service life as they support ever larger wind turbines under complex loading situations. There have been numerous reports of cracked concrete foundations of wind turbines. Cracking can impair the durability and serviceability of the foundations, thereby leading to very expensive repairs or even to premature failure of the structure. To avoid cracking-related problems and improve the quality of concrete foundations, it is important to gather information and experience from the production stage and its outcome. However, although problems and defects in the construction of wind turbine foundations are widespread, they have very seldom been documented and reported, in particular from a contractor’s perspective. This article analyses and critically reviews data collected during the production, inspection, diagnosis, and repair activities conducted in relation to the construction of foundations for a wind farm project in Sweden. The extent of defects observed on individual foundations is assessed and used to investigate the eventual relation between the observed deviations and different production aspects. Investigation methods to determine the importance of these defects and their consequences and possible remediation measures are also discussed. Finally, recommendations are proposed to improve the quality control of wind turbine foundations.
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| 6. |
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| 7. |
- Williams Portal, Natalie, 1986, et al.
(författare)
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Bending behaviour of novel Textile Reinforced Concrete-foamed concrete (TRC-FC) sandwich elements
- 2017
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Ingår i: Composite Structures. - : Elsevier BV. - 0263-8223 .- 1879-1085. ; 177, s. 104-118
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Tidskriftsartikel (refereegranskat)abstract
- A novel sandwich element design consisting of two facings made of carbon reinforced Textile Reinforced Concrete (TRC), a low density foamed concrete (FC) core and glass fibre reinforced polymer (GFRP) connecting devices was experimentally investigated according to quasi-static and cyclic quasi-static four-point bending. Optical measurements based on Digital Image Correlation (DIC) were taken during testing to enable a detailed analysis of the bending behaviour and level of composite action. A model, verified by the experiments, was developed based on non-linear finite element analysis (NLFEA) to gain further insight on the failure mechanisms. Under both loading conditions, the bending behaviour of the TRC-FC composite elements was characterized by favourable load bearing capacity, partial composite action, superior ductility and multiple fine cracking. The connecting devices were found to be the critical elements causing the initial failure mechanism in the form of localized pull-out within an element.
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| 8. |
- Bournas, Iason, et al.
(författare)
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Energy renovation of an office building using a holistic design approach
- 2016
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Ingår i: Journal of Building Engineering. - : Elsevier BV. - 2352-7102. ; 7:September 2016, s. 194-206
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents a holistic approach to perform energy renovations of office buildings. A real case study is used to demonstrate how different software can be used to facilitate the work of architects and engineers during different design stages. Initially, the moisture safety of the building is coupled to its energy performance to define the optimum insulation level. The new interior layout is based on an initial daylight study, rather than on architectural intuition. On a second stage, shading and natural ventilation are studied to eradicate any cooling demand, while the interdependence between heating energy and daylight is assessed for the use of light-wells. To demonstrate the trade-offs between visual control and electrical lighting, different shading systems are examined for a cellular office. Finally, two alternate HVAC systems are analyzed to investigate whether passive standards can be achieved with an all-air system and/or a hydronic system.
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| 9. |
- Crocetti, Roberto, et al.
(författare)
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Stress-laminated-timber decks: state of the art and design based on Swedish practice
- 2016
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Ingår i: European Journal of Wood and Wood Products/Holz als Roh - und Werkstoff. - : Springer Science and Business Media LLC. - 1436-736X .- 0018-3768. ; 74:3, s. 453-461
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Tidskriftsartikel (refereegranskat)abstract
- Stress-laminated-timber (SLT) bridge decks area valid alternative to conventional short- and medium-spanbridges in terms of cost and performance. SLT decks aremade from a number of planks or glulam beams positionedside by side and stressed together using high-strength steelbars. A concentrated load can therefore be distributed fromthe loaded beams onto adjacent beams due to the resistingfriction caused by the pre-stressing of all beams in thedeck. This paper describes the state of the art of SLT bridgedecks, with special emphasis on Swedish practice. Theeffect of butt joints on deck deflection and solution appliedto accommodate the loss of pre-stress are shown. Simpledesign tools for the preliminary design of road bridges areillustrated. Best practice with regard to some detailing,water protection and durability is also discussed. Finally,possible developments of SLT bridges are discussed.
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| 10. |
- van Eldert, Jeroen, 1987-, et al.
(författare)
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Application of Measurement While Drilling Technology to Predict Rock Mass Quality and Rock Support for Tunnelling
- 2020
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Ingår i: Rock Mechanics and Rock Engineering. - : Springer. - 0723-2632 .- 1434-453X. ; 53:3, s. 1349-1358
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Tidskriftsartikel (refereegranskat)abstract
- A tunnelling project is normally initiated with a site investigation to determine the in situ rock mass conditions and to generate the basis for the tunnel design and rock support. However, since site investigations often are based on limited information (surface mapping, geophysical profiles, few bore holes, etc.), the estimation of the rock mass conditions may contain inaccuracies, resulting in underestimating the required rock support. The study hypothesised that these inaccuracies could be reduced using Measurement While Drilling (MWD) technology to assist in the decision-making process. A case study of two tunnels in the Stockholm bypass found the rock mass quality was severely overestimated by the site investigation; more than 45% of the investigated sections had a lower rock mass quality than expected. MWD data were recorded in 25 m grout holes and 6 m blast holes. The MWD data were normalised so that the long grout holes with larger hole diameters and the shorter blast holes with smaller hole diameters gave similar results. With normalised MWD data, it was possible to mimic the tunnel contour mapping; results showed good correlation with mapped Q-value and installed rock support. MWD technology can improve the accuracy of forecasting the rock mass ahead of the face. It can bridge the information gap between the early, somewhat uncertain geotechnical site investigation and the geological mapping done after excavation to optimise rock support.
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