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Software Tutorials
FLAC3D 6.0 Easily Add Structural Support
Homogeneous Embankment Dam Analysis (Part 2 of 3)
This FLAC 8.1 tutorial demonstrates how to conduct a steady-state seepage analysis to calculate the pore water pressures in the embankment due to the reservoir.
FLAC3D 7 Zone Plotting Tutorial
This tutorial will show how to create and manipulate zone plot items for showing model attributes and results.
Technical Papers
Use of a Finite Element Code to Model Complex Mine Water Problems
Numerical models are now used routinely to predict ground-water inflows to both surface and underground mines and to help design dewatering systems.
The nexus between groundwater modeling, pit lake chemogenesis and ecological risk from arsenic in the Getchell Main Pit, Nevada, U.S.A.
The proliferation of mine pits that intersect the groundwater table has engendered interest in environmental consequences of the lakes that form after cessation of dewatering.
Tunnelling and reinforcement in heterogeneous ground – A case study
Abstract
A case study of tunnelling in heterogeneous ground conditions has been analysed. The case involves a tunnel excavated in mixed-face conditions, where the main host material was rock, but for a distance of about 30 m, the tunnel had to be driven through a thick layer of soil, primarily moraine and sandy soil materials.During tunnel drifting, a "chimney" cave developed through the soil layer, resulting in a surface sinkhole.This case was analysed using a three-dimensional numerical model with the FLAC3D software code, in which the soil stratigraphy and tunnel advance were modelled in detail. Tunnel and soil reinforcement in the form of jet grouting of the soil, pipe umbrella arch system, bolting, and shotcreting, was explicitly simulated in the model. The studyaimed at comparing model results with observations and measurements of ground behaviour, and to replicate the major deformation pattern observed. The modelling work was based on a previous generic study in which various factors influencing tunnel and ground surface deformations were analysed for different cases of heterogeneous ground conditions.Model calibration was performed through adjusting the soil shear strength. The calibration provided a qualitatively good agreement with observed behaviour. Calculated deformations on the ground surface were in line with measured deformations, and the location of the tunnel collapse predicted by the model. The installed tunnel reinforcement proved to be critical to match with observed behaviour. Without installed pipe umbrella arch system, calculated deformations were overestimated, and exclusion of jet grouting caused collapse of the tunnel. These findings prove that, in particular, jet grouting of the soil layer was necessary for the successful tunnel advance through the soil layer.