A new rating system for hydrogeological risk management along railway infrastructures in Prealpine zone (northern Italy)

AbstractRailway infrastructures in mountain areas often develop along hillslopes affected by geomorphological and hydrogeological processes which might lead hazardous events. Therefore, specific tools for risk analysis and management are required. This paper develops a new rating system (Railway Hydrogeological Management System, RHMS), based on a heuristic method which considers the susceptibility to different types of slope instabilities, as well as the peculiar features affecting the railway vulnerability. The proposed method introduces an iterative approach for the risk assessment, based on the definition of acceptability thresholds for the residual risk. The application of this method to a test area pointed out its feasibility, as well as its operational capability to identify the critical sections of the infrastructure, in which protection or mitigation measures are needed in order to reduce the risk

Short review of some methods for groundwater flow assessment in fractured rock masses

Water flow in fractured rock masses is a key issue in many typical environmental and engineering problems. Still, aquifers in fractured rocks are devoted much less attention than those in porous media, as they are considered less important from the point of view of water research, but also because rock masses are a very complex medium (heterogeneous, anisotropic and discontinuous), and therefore its modelling is a quite hard task. This paper proposes a review on recent researches concerning groundwater flow in fractured rock masses. In particular, the main issues involved in the reconstruction of the hydrogeological conceptual model are addressed, mainly for fissured and partly for karsts rocks, and the following choice of the most suitable modeling approach is critically discussed, through applicative examples

An empirical equation for tunnel inflow assessment: application to sedimentary rock masses

reserved2Groundwater inflow assessment is essential for the design of tunnel drainage systems, as well as for assessment of the environmental impact of the associated drainage. Analytical and empirical methods used in current engineering practice do not adequately account for the effect of the jointed-rock-mass anisotropy and heterogeneity. The impact of geo-structural anisotropy of fractured rocks on tunnel inflows is addressed and the limitations of analytical solutions assuming isotropic hydraulic conductivity are discussed. In particular, the study develops an empirical correction to the analytical formula frequently used to predict groundwater tunnel inflow. In order to obtain this, a discrete network flow modelling study was carried out. Numerical simulation results provided a dataset useful for the calibration of some empirical coefficient to correct the well-known Goodman’s equation. This correction accounts for geostructural parameters of the rock masses such as joint orientation, aperture, spacing and persistence. The obtained empirical equation was then applied to a medium-depth open tunnel in Bergamo District, northern Italy. The results, compared with the monitoring data, showed that the traditional analytical equations give the highest overestimation where the hydraulic conductivity shows great anisotropy. On the other hand, the empirical relation allows a better estimation of the tunnel inflow.P. Gattinoni; L. ScesiGattinoni, Paola; Scesi, LAURA TERESA GIUSEPPIN

Realizzazione di gallerie mediante cunicolo pilota: studio dell’ “effetto scala” (Parte II)

none2M. Papini; L. ScesiPapini, Monica; Scesi, LAURA TERESA GIUSEPPIN