Software Tutorials
FLAC3D 7 0 Cutting Tool Tutorial
This tutorial will show how to use the Plot Item Cutting Tool in FLAC3D 7. Creating cut plans is useful for seeing inside 3D model plots. FLAC3D cutting planes include a single-surface plane, a double-surface wedge, and a three-surface octant.
FLAC3D 6.0 PFC Plugin Punch
PFC 7 Creation of a Synthetic Rock Mass (SRM) Specimen
This tutorial will guide you through how to create a fractured Synthetic Rock Mass (SRM) specimen.
Technical Papers
Flowback Test Analyses at the Utah Frontier Observatory for Research in Geothermal Energy (FORGE) Site
Injection testing conducted in 2017 and 2019 at the Frontier Observatory for Research in Geothermal Energy site in Utah evaluated flowback as an alternative to prolonged shut-in periods to infer closure stress, formation compressibility, and formation permeability. Flowback analyses yielded lower inferred closure stresses than traditional shut-in methods and indicated high formation compressibility, suggesting an extensive fractured system. Numerical simulations showed rebound pressure is not necessarily the lower bound of minimum principal stress. Stiffness changes can be identified as depletion transitions from hydraulic to natural fractures. The advantage if flowback is reduced time to closure.
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.
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.