Publications

Modelling the construction and long-term response of Göta Tunnel

Year: 2021
Author(s): Johannes Tornborg, Mats Karlsson, Anders Kullingsjö, Minna Karstunen
Publication Type: Journal article

This paper presents a benchmark of a rate-dependent constitutive model for soft soils, implemented in a 2D finite element code, against the response of an instrumented excavation in sensitive clay: Göta Tunnel in Gothenburg. The monitoring data, which comprise time-series of pore water pressures, displacements, earth pressures and strut forces, provide valuable insights of the time-dependent response during the construction period. The long-term response, in terms of the ongoing settlement rates, is assessed using remote sensing data. The results of the numerical simulations demonstrate that the constitutive model, Creep-SCLAY1S, is capable of capturing the observed response. The trends of vertical and horizontal displacements are captured well until the stage of dewatering, and the evolution of pore pressures and earth pressures is computed with high accuracy, excluding peaks in the measurement values arising from pile and rock anchor installation. Most importantly, the results demonstrate that the rate-dependent model enables to model the complete service life of the tunnel, from construction of the excavation to the tunnel operation, with one unified model parameter set. Furthermore, the comparisons highlight the importance of assessing installation effects both in the choice of construction methods and modelling.


An entity-relationship model of the flow of waste and resources in city-regions: Improving knowledge management for the circular economy

Year: 2021
Author(s): Jonathan Edgardo Cohen, Jorge Gil
Publication Type: Journal article

Waste and resources management is one of the domains where urban and regional planning can transition towards a Circular Economy, thus slowing environmental degradation. Improving waste and resources management in cities requires an adequate understanding of multiple systems and how they interact. New technologies contribute to improve waste management and resource efficiency, but knowledge silos hinder the possibility of delivering sound holistic solutions. Furthermore, lack of compatibility between data formats and diverse definitions of the same concept reduces information exchange across different urban domains. This paper addresses the challenge of organising and standardising information about waste and resources management in city regions. Given the amount and variety of data constantly captured, data models and standards are a crucial element of Industry 4.0. The paper proposes an Entity-Relationship Model to harmonise definitions and integrate information on waste and resources management. Furthermore, it helps to formalise the components of the system and their relationships. Semi-structured interviews with government officials, mobile app developers and academics provided insights into the specific system and endorsed the model. Finally, the paper illustrates the translation of the ERM into a relational database schema and instantiates Waste Management and industrial Symbiosis cases in Buenos Aires (ARG) and Helsingborg (SWE) to validate its general applicability. The data model for the Circular Flow of Waste and Resources presented here enhances traditional waste management perspectives by introducing Circular Economy strategies and spatial variables in the model. Thus, this research represents a step towards unlocking the true potential of Industry 4.0.


From soft soil modelling to engineering application

Year: 2021
Author(s): Minna Karstunen
Publication Type: Paper in proceeding

Soft soil engineering is still a challenge, in particular when we increasingly need to construct on densely populated urban areas next to existing structures, and need to deal with the effects of climate change. The paper discusses the systematic research by the author and her co-workers in the last 20 years that has resulted in the development and validation of advanced soil models, specifically geared for Scandinavian soft soil conditions. The culmination of this research is Creep-SCLAY1S, a rate dependent anisotropic model, which is backed by hierarchical development and systematic validation. Some recent examples of engineering applications where the model was used are are highlighted, in addition to the parameter determination and calibration.


Experience from short-and long-term performance of deep excavations in soft sensitive clays

Year: 2021
Author(s): Johannes Tornborg, Mats Karlsson, Anders Kullingsjö, Minna Karstunen
Publication Type: Paper in proceeding

Design of excavations and permanent underground structures requires accurate predictions of e.g. deformations and earth pressures for both the short-and long-term. As excavation depths increase and/or the proximity to adjacent infrastructure decreases, there is a need to improve and develop existing design methods and validate numerical models. The first part of this paper revisits the measurement data from a previous excavation, the Göta Tunnel in Gothenburg, Sweden, in order to benchmark a contemporary constitutive soil model, called Creep-SCLAY1S. This study looks into time series including e.g. final dewatering of the excavation, followed by the development of pore water pressures, earth pressures and deformations over time (until 2 years after excavation). The model predictions are in general in good agreement with the measurement data up to final dewatering. However, installation effects due to drilling are believed to have caused continued deformations which are difficult to capture in the numerical model. Part two of the paper presents details of a recently instrumented excavation in soft clay in Central Gothenburg. The measurement data comprises e.g. pore water pressures, deformations as well as vertical and horizontal earth pressures at three locations under the permanent structure. Continued long-term measurements are planned and the existing and future data are believed to provide valuable insights on the development of the stress state and earth pressures under permanent structures in soft clay.


Att synliggöra det osynliga - Kartläggning av representation av miljödata i digitala modeller

Year: 2021
Author(s): Beata Stahre Wästberg, Liane Thuvander, Susanne Van Raalte, Monica Billger
Publication Type: Report

En av de stora utmaningarna för infrastrukturplanering idag handlar om hur man samlar, hanterar och kommunicerar stora mängder data. Effekten som ett projekt kommer att ha på miljö och klimat är svår att visa på ett visuellt begripligt sätt. Därför får detta ofta låg prioritet inom fysisk planering och kommer in sent i planeringsprocessen. Trafikverket hanterar miljöparametrar i så kallade samordningsmodeller vilka visar ett stort landskapsområde i en översiktlig skala, där man samlar alla data kopplat till ett projekt. Idag saknas det dock riktlinjer för hur data ska koordineras och standardiseras i dessa modeller.

Den här rapporten är en omvärldsanalys och beskriver en inventering av projekt som fokuserar på visualisering av miljöparametrar i digitala modeller. Syftet är att dra lärdom av dessa som stöd för att kunna utveckla designkoncept för standardiserad visualisering i samordningsmodeller. Inventeringen vänder sig främst till Trafikverkets specialister, samt forskare inom visualiseringsområdet.

Resultaten från omvärldsanalysen presenteras som en projektsammanställning, utifrån miljöområdena buller, luftkvalitet, social konsekvensanalys samt exempel på digitala tvillingar kopplade till stadsmodeller. I inventeringen definieras även centrala visualiseringskomponenter för representation av data, och vi studerar hur dessa används inom de olika miljöområdena. Rapporten avslutas med en diskussion kring grafisk och rumslig representation, där vi beaktar aspekter som visuella former och visuella egenskaper, vilken dimension (2D eller 3D) data har visualiserats, samt perspektiv och skalor.

Inventeringen ingår i projektet MiljöVis - Effektiv representation av miljöinformation i infrastukturmodeller vars syfte är att utveckla ny kunskap om hur Trafikverkets samordningsmodeller kan bli ett effektivare och tydligare kommunikationsmedel och kvalitetsverktyg. Projektet syftar också till att utveckla nya visualiseringslösningar för integrering av miljödata och sociala aspekter.


MiljöVis: Effektiv representation av miljödata i digitala modeller

Year: 2021
Author(s): Beata Stahre Wästberg, Monica Billger, Liane Thuvander, Fabio Latino, Sanjay Somanath, Susanne van Raalte
Publication Type: Report

Effektiv visualisering gör att man kan inkludera och skapa samsyn bland intressenterna i planeringsprocessen och på så sätt bidra till en helhetssyn och därmed hållbarare lösningar. Projektet MiljöVis - Effektiv representation av miljöinformation i infrastrukturmodeller är ett samarbete mellan Chalmers/Digital Twin Cities Centre och Trafikverket, som syftar till att utveckla metoder för att representera miljödata i Trafikverkets samordningsmodeller. I projektet har olika koncept för visualiseringslösningar utvecklats som sedan undersökts i en serie användartester. För att kunna demonstrera olika visualiseringslösningar i Trafikverkets samordningsmodeller ingick utveckling av ett arbetsflöde för att generera digitala tvilling-modeller och visualisera storskaliga data. Utifrån detta har vi utvecklat rekommendationer för implementering av visualiseringar, vilka redovisas i den här rapporten.

I rapporten ingår en stor mängd bildmaterial från användarstudiernas, som här används främst som illustrationer. Skulle någon vilja ta del av detta material, var vänlig kontakta rapportförfattarna.


AI-baserad segementering av fasader för att optimera renovering i en större skala

Year: 2021
Author(s): Sanjay Somanath, Yinan Yu, Nils Nordmark, Mola Ayenew, Liane Thuvander, Alexander Hollberg
Publication Type: Magazine article

Hur kan vi på ett automatiskt sätt skapa mer detaljerade 3D modeller av byggnader i digitala tvillingar och förbättra indata för att beräkna energibesparingspotentialer i befintliga byggnader? I en pilotstudie har vi undersökt hur maskininlärning kan användas för att extrahera information om fönstersättning och storlek i befintliga byggnader. Vi har utvecklat en modell som har “tränats” att känna igen och segmenterar fönster från bilder med byggnadsfasader och på så sätt skapa digitala och mer detaljerade data för befintliga byggnader. Vårt långsiktiga mål är att utveckla en helautomatisk metod för analyser av renoveringspotentialer för byggnader och fastighetsportföljer.


City Information Modelling: Digital Planning for Sustainable Cities

Year: 2020
Author(s): Jorge Gil
Publication Type: Other text in scientific journal

No abstact available


Towards spatial integration of qualitative data for urban transformation – challenges with automated geovisualization of perception of urban places

Year: 2020
Author(s): Liane Thuvander, Fabio Latino, Christoforos Zangelidis, Marco Adelfio, Vasilis Naserentin, Anders Logg
Publication Type: Paper in proceeding

Urban planning needs to face and integrate ecological, social, and economic aspects of city living. So far, attempts to integrate different urban simulation models into one technical platform have focused on quantitative data. The aim of this paper is to present the preparation for an automated method to spatially integrate and visualize interview-based qualitative data on the perception of urban places into a virtual platform. The Gothenburg suburb of Hammarkullen is used as a case study. Two CAQDAS software, NVivo and Atlas.ti, were tested. In both
software, locations and urban qualities were coded and clustered. Visualization strategies such as information tree structures, geo-coded quotations, spatial word clouds, linked to 2D maps and 3D environments were developed. Results identify the challenges to overcome and show limitations of the software in terms of creating graphs and relationships as well as automated geocoding of data to maps. The project offers a step towards the integration of qualitative (social)
data into digital environments that can be scaled up. By that, it contributes with a new dimension of analysis of urban environments which is necessary for sustainable transformation of cities.


Data-Informed Urban Design: An Overview of the Use of Data and Digital Tools in Urban Planning and Design

Year: 2020
Author(s): Alexander Gösta, André Agi, Jacob Flårback, Jesper Karlsson, Ellen Simonsson
Publication Type: Journal article

This article aims to map how different digital tools can be useful for architects and how they might affect their work processes. Researchers and professionals were interviewed to investigate what they found valuable to measure, which methods they used within their analyses, as well
as the opportunities and risks they see for the future of the field with regards to digital tools. As part of the survey, a workshop was held with architects and project managers examining the possibilities of connecting existing methods and tools to the sustainability certification system,
City Lab Action Guide, and through that, to achieve a more ambitious set of sustainability goals for the projects. Findings from the study indicate that there are risks associated with giving data an increasingly important role in the design work. A working model never provides the full truth
but is inherently limited by its constraints. It is important to acknowledge that all angles and aspects of a problem can never be represented in a model. Another possible risk identified lies in the quality of, and access to, data. In a scenario where data plays an increasingly important
role, it is not only the quality of the datasets that is of utmost importance, but it is equally important that the urban planners who request the analyses ask the questions first, and then collect the necessary data, instead of vice versa.


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