E18 West Corridor - Modelling of pore pressure conditions related to tunnelling and deep excavation pits in urban landscape
The main objective of this master thesis is to develop a new method for assessing the influence of construction workers on the pore pressure state, using analysis of measurement data and simulations.
( Statens Vegvesen)
European roads, railways, subways, and other infrastructure are increasingly being laid underground. Such projects are associated with risk regarding the impact on the local environment and construction - especially when the tunnels are laid close to or under existing constructions.
Drainage of groundwater and subsequent settlement potential is a key concern in tunnelling in urban environments. There are several examples of tunnel projects with major challenges related to this. Perhaps the most famous in Norway is the railway tunnel to Gardermobanen (Romeriksporten), developed in the 90s. Still, to this day, the consequences of this project are being dealt with.
Tunnels, deep construction pits, and other foundation works in the urban landscape must be secured against infiltration to minimize the risk of damage to neighbouring structures. This often involves very expensive measures. Such measures are usually designed based on experience and engineering judgement.
Modern technology and instrumentation allow us to collect vast amounts of precise data. To properly take advantage of this, it is necessary to develop better digital models that are scientifically grounded and statistically valid. This way, more cost-effective solutions can be designed whilst minimizing the risk of negative consequences.
E18 West Corridor is a large road project under construction west of Oslo. Parts of today's European road are to be replaced by tunnel. This tunnel will go under a densely populated landscape. Therefore, an elaborate instrumentation scheme has been planned to monitor the performance of excavation pits and tunnels, with respect to water leakage.
Pore pressure and weather time series have been collected for a large area. This data goes back several years prior to construction, and data is continuously being collected during the construction phase. In addition, analysis of satellite-based settlement measurements (InSAR) and manual measurements of settlements on structures are analysed.
The assignment
The student who chooses this master's thesis will have a unique opportunity to help develop methodologies and models used in today's and tomorrow's digitized construction industry.
The student will be able to work with some of Norway's leading professionals on this topic.
The assignment can be designed and adapted to the candidate's skills and interests.
Task suggestions:
- Assessment/modelling of climate influence on pore pressure state, using time series analysis of measurement data (PASTAS - https://ngwa.onlinelibrary.wiley.com/doi/full/10.1111/gwat.12925)
- Analysis of tests on water infiltration wells
- Numerical/analytical sensitivity analyses of different tunnel leakage scenarios
- Assessment of water leakage thresholds in deep channels by back-calculation of infiltration tests
- Area assessment of settlement potential and impact analyses
