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Software Tutorials
Bonded Block Model with Cable Ground Support
Cable elements in 3DEC may be assigned a tensile yield force limit and an axial rupture strain in order to simulate cable rupture. 3DEC can also simulate the shearing resistance along the cable length between the grout and either the cable or the host material.
FLAC3D 7.0 Geometry Painting Tutorial
This tutorial will show how to paint zone data onto an imported geometric surface in FLAC3D.
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
Formulation and Application of a Constitutive Model for Multijointed Material to Rock Mass Engineering
This paper presents the formulation of a constitutive model to simulate the behavior of foliated rock mass. The 3D elastoplastic constitutive model, called Comba, accounts for the presence of arbitrary orientations of weakness in a nonisotropic elastoplastic matrix.
Elastic Properties of Fractured Rock Masses With Frictional Properties and Power Law Fracture Size Distributions
We derive the relationships that link the general elastic properties of rock masses to the geometrical properties of fracture networks, with a special emphasis to the case of frictional crack surfaces.
We extend the well-known elastic solutions for free-slipping cracks to fractures whose plane resistance is defined by an elastic fracture (shear) stiffness ks and a stick-slip Coulomb threshold.
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.