Proppant in Fluid Filled Joints

The transport and placement of proppant within fractures is modeled in 3DEC by representing the proppant and fracturing fluid as a mixture.

FLAC3D 7.0 Geometry Mesh Tutorial

This tutorial demonstrates how to generate a 3D volume mesh from surface geometry imported from DXF or STL files. Both hexahedral-dominant and tetrahedral meshes can be generated automatically using the "zone generate from-geometry ..." command in FLAC3D 7. The results of various keywords are shown.

An Introduction to Python Scripting: Part 2

Introduction to Python scripting by reviewing key concepts and through demonstrations. Part 2 focuses on classes and objects plus lists and dictionaries.

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.

Three-dimensional Modeling and Stress Calibration for a Complex Mining Geometry

Study stress situation for potential continued mining towards greater depths; stress calibration against stress measurements using numerical modeling; and use of calibrated model to study stresses at existing infrastructure, study stresses at potential future haulage level locations, and as input to local models.

Tunneldrivning i heterogena förhållanden

InledningProblem: Brist på erfarenhet av tunneldrivning i heterogena förhållanden med konventionell uttagsteknik (borrning och sprängning).

Mål: Fördjupa kunskapen och förståelse av brott och deformationsmönster vid dessa förhållanden.