Mathematical Modeling of Groundwater Flow – Foundation Piles in the Vicinity of Danube River Case Study

Abstract

The study investigates an interaction of groundwater flow and foundation piles located in the vicinity of the Danube River. The piles represent an obstacle to the groundwater flow, causing the backwater effect upstream, whilst increasing the local flow velocity. On the other hand, high flow velocity around the piles can cause the suffusion of the surrounding soil in the long term, thus significantly reducing the shaft resistance of the piles. A 3D model of groundwater flow and its impact on the piles was developed in the software package GMS.9.2 based on MODFLOW 2005. It was calibrated by comparing the water level values obtained as a result of the simulations with varying filtration coefficient inputs with the observed values in the monitoring well. After the calibration process, piles were implemented into the model and the underground flow was simulated at the study area location for the calibrated year 2006. The impact analysis was carried out by comparing the groundwater level change over time in the pile zone in three control points, in cases with and without the piles, along with the flow net analysis at the location of the piles themselves. The obtained results indicate an absence of the influence of piles on the groundwater flow at the study area location, both in terms of critical flow velocities and in terms of a possible backwater effect upstream.