Université de Neuchâtel

Long-term effects of deep-seated landslides on transportation infrastructure : a case study from the Swiss Jura Mountains

Preisig, Giona

In: Quarterly Journal of Engineering Geology and Hydrogeology, 2018, vol. 2017, p. 128-137

Deep-seated landslides (DSLs) involve large-scale deformation and likely affect transportation infrastructure. Movement rates are in general very slow (less than a metre per year) with acceleration periods controlled by external factors such as the seasonal fluctuation of groundwater pressure. Acceleration response may change from season to season depending on hydrogeological conditions, changes...

Université de Neuchâtel

Regional Flow and Deformation Analysis of Basin-Fill Aquifer Systems Using Stress-Dependent Parameters

Preisig, Giona ; Cornaton, Fabien Joel ; Perrochet, Pierre

In: Ground Water, 2014, vol. 52, no. 1, p. 125-135

Changes in effective stress due to water pressure variations modify the intrinsic hydrodynamic properties of aquifers and aquitards. Overexploited groundwater systems, such as basins with heavy pumping, are subject to nonrecoverable modifications. This results in loss of permeability, porosity, and specific storage due to system consolidation. This paper presents (1) the analytical development of...

Université de Neuchâtel

Simulation of flow in fractured rocks using effective stress-dependent parameters and aquifer consolidation

Preisig, Giona ; Cornaton, Fabien Joel ; Perrochet, Pierre

In: Proceedings of the ModelCARE, 2011, p. 273-279

Effective stress plays an important role in aquifer dynamics, especially in those affected by high variations of water pressures. Increasing/decreasing effective stresses affect hydrogeological parameters, even in media of high stiffness, such as fractured rocks. This study presents a modelling approach of groundwater flow in fractured rocks and aquifer deformation taking into account the...

Université de Neuchâtel

Modelling Discharge Rates and Ground Settlement Induced by Tunnel Excavation

Preisig, Giona ; Dematteis, A. ; Torri, R ; Monin, N. ; Milnes, Ellen ; Perrochet, Pierre

In: Rock Mechanics and Rock Engineering, 2014, vol. 47, no. 3, p. 869-884

Interception of aquifers by tunnel excavation results in water inflow and leads to drawdown of the water table which may induce ground settlement. In this work, analytical and numerical models are presented which specifically address these groundwater related processes in tunnel excavation. These developed models are compared and their performance as predictive tools is evaluated. Firstly, the...

Université de Neuchâtel

Regional simulation of coupled hydromechanical processes in fractured and granular porous aquifer using effective stress-dependent parameters

Preisig, Giona ; Perrochet, Pierre (Dir.)

Thèse de doctorat : Université de Neuchâtel, 2013.

Field observations and laboratory experiments have clearly demonstrated that heavily perturbed / exploited aquifers are subject to 3D deformations, which may cause significant socio-economic impacts at regional scale. Most common examples include: (1) excessive pumping of groundwater from deep aquifers leading to land subsidence; (2) deep excavation of tunnels in permeable geological units...

Université de Neuchâtel

Regional Flow Simulation in Fractured Aquifers Using Stress-Dependent Parameters

Preisig, Giona ; Cornaton, Fabien Joel ; Perrochet, Pierre

In: Ground Water, 2011, p. 1-10

A model function relating effective stress to fracture permeability is developed from Hooke's law, implemented in the tensorial form of Darcy's law, and used to evaluate discharge rates and pressure distributions at regional scales. The model takes into account elastic and statistical fracture parameters, and is able to simulate real stress-dependent permeabilities from laboratory to field...