RS3 A New 3D Program for Geotechnical Analysis

Rocscience is announcing the upcoming release of a brand

new software program for 3-dimensional analysis and design

of geotechnical structures – RS3 – a general purpose finite

element analysis program for underground excavation, tunnel

and support design, surface excavation and foundation design,

consolidation, groundwater seepage and more.

What is RS3?RS3 is the culmination of 10 years of development and re-

search at Rocscience. Equally applicable for both rock and soil,

the name RS3 stands for:

RS3 = Rock and Soil 3-dimensional analysis program.

As a branding tie-in, you can also think of RS as short for

RocScience (just so you don’t forget about us!). Although Roc-

science has established itself as a world leader in geotechnical

analysis software for rock engineering, Rocscience programs

including Slide, Phase2 and Settle3D are also widely used for

soils, and have been for many years. RS3 now joins the suite of

Rocscience software which can be used for both rock and soil

geotechnical engineering analysis.

Due to the complexity of the program, RS3 will undergo an

extended period of beta testing starting in April 2013. We

expect to release 3 or 4 beta updates during the course of the

summer, until the final release of RS3 version 1.0 in the fall of

2013.

Feedback obtained during the beta testing will be used to

improve, refine and expand the program features, analysis ca-

pabilities and interface for the final release version. To get you

started, several tutorials and verification examples have been

prepared for the beta release.

To sign up for the RS3 Beta Testing Program, contact Cathy

Weston at software@rocscience.com.

Displacement contours on vertical planes through open pit mine

RS3 Program Capabilities

RS3 is a 3-dimensional analysis program and uses the finite

element method to solve geotechnical engineering problems

involving stress/displacement analysis, groundwater flow, con-

solidation and more. The modeling and analysis capabilities of

RS3 include:

Tunnel designComplex multi-stage tunnel excavations and support systems.

Excavation designGeneral underground excavations such as caverns, mine exca-

vations.

Surface excavationsExcavations for building foundations and support systems,

slopes, embankments, retaining walls, surface excavation for

open pit mines.

Excavation supportComplex support systems for underground or surface excava-

tions, using bolts, liners, sheet pile walls, soldier piles, steel

sets, beams, trusses, forepoles.

Groundwater seepage analysisSteady state or transient finite element seepage analysis with

3-dimensional flow and boundary conditions, fully integrated

with excavation and stress analysis.

Coupled stress /pore pressure analysisFor soil effective stress analysis and consolidation, coupled

stress and pore pressure analysis using Biot Theory.

Slope stability3D slope stability can be carried out by manual reduction of

shear strength parameters.

Displacement contours around surface excavation with tiebacks and sheet pile support

Model Geometry

RS3 version 1.0 has two main geometric modeling modes:

• A horizontal mode in which the primary axis of the model

is horizontal – this is referred to as Tunnel Mode although

it covers any type of model with a primary horizontal axis.

• A vertical mode in which the primary axis of the model is

vertical – this is referred to as Foundation Mode although

it is used for any type of model with a primary vertical axis.

3-dimensional model geometry is built up by creating a series

of extruded 2-dimensional slices. Excavation and material

boundaries can be defined independently for each slice, allow-

ing you to easily create complex 3D models from a series of

extruded 2D slices. The direction of extrusion is either horizon-

tal or vertical according to the mode described above. Each

slice has a user-defined thickness and can be further subdi-

vided into thinner partitions for more detailed sequencing and

support design.

This system makes it simple to create 3D models from an as-

sembly of extruded 2D slices. Since geometry can be defined

independently for each slice, this allows you to create truly

3-dimensional models with a minimum of effort, such as the

open pit mine in the figure, lower right.

Simple models demonstrating Tunnel mode and Foundation mode

Open pit mine constructed by importing a series of DXF files for multiple slices

Staging and Sequencing

Advanced staging capabilities are essential for 3-dimensional

modeling. RS3 offers complete flexibility for staging of exca-

vations, support installation, loading and all other modeling

aspects. The number of stages is defined in the Project Settings

dialog. Models with up to several hundred different stages can

be analyzed with RS3.

Project Settings dialog stage definition

To assist with the assignment of staging, excavation and sup-

port, a Sequence Designer dialog, to the right, is provided.

This is invaluable for the assignment of complex, repetitive

staging sequences.

Staging of ore removal and backfill for mine orebody

Sequence Designer for Excavation assignment

Staging and Sequencing

Staging assignments can also be defined or customized “manually”

as necessary for situations not covered by the Sequence Designer

dialog, using the individual menu options provided.

Using sequence designer to assign excava-tion sequence for twin tunnel excavations

Sequence Designer

for Support assignment

Slices can be spaced out for ease of viewing

Materials

RS3 has material models for both soil

and rock, including Mohr-Coulomb,

Generalized Hoek-Brown, Cam Clay and

Drucker-Prager strength models.

Elastic models include isotropic, trans-

versely isotropic, orthotropic and Duncan

Chang Hyperbolic.

Any number of different material types

can be defined for a model, and materi-

als can be easily assigned to different

regions with a few mouse clicks, or with

the aid of the Sequence Designer.

Material Properties dialog, Mohr-Coulomb isotropic

Support

Bolt types include End Anchored, Tieback, Fully Bonded, Plain Strand Cable,

Swellex, Split Set. Liners can represent shotcrete or concrete support. Beams

can represent steel sets or trusses. Piles can be used to model various pile types

for excavation support or forepoles used for tunnel support. Composite liners

with sliding interfaces can be created by defining multiple liner layers and

sequencing in the composite liners dialog.

Clockwise from top left:

Bolt support for multi-heading staged tunnel

Steel set and liner installation

Total displacements around supported tunnel

For the support of excavations, slopes, foundations, retaining

walls and embankments, a variety of different support types

and options are available in RS3. The four main support ele-

ments offered in RS3 are:

• Bolts• Liners

• Beams• Piles

Support

The support options in RS3 provide very powerful modeling of sophisticated

support systems for 3-dimensional geotechnical models.

Tunnel Face Stability:Forepoles used to support advancing face of staged tunnel Tieback and

sheet pile support for foundation excavation

Groundwater

RS3 includes 3-dimensional finite element

seepage analysis for the determination of

groundwater pore pressure and flows. The

groundwater analysis is fully integrated with

all other aspects of the program, and can be

used in conjunction with stress analysis, or as

an independent groundwater seepage analy-

sis.

Steady state or transient groundwater flow

can be analyzed. Furthermore, RS3 offers fully

coupled analysis of stress / pore pressure using

Biot theory for the most accurate modeling of

soil behavior where the interaction of stress

and pore pressure are critical, such as em-

bankment consolidation, surface excavations

or shallow tunnels through clay materials.

Groundwater boundary conditions for transient flow embankment model

Total head contours for transient flow embankment model

Groundwater

For simple groundwater modeling, RS3 also

allows pore pressure to be defined

using piezometric surfaces

or pore pressure grids.

Flow vectors water at t=150 days

Boundary Conditions and Loading2D Model

Groundwater and displacement boundary conditions for 2D embankment model

Solid restraints and boundary conditions; Fixed normal to the plane, and pinned at the bottom.

Groundwater boundary conditions; Water table located at 1m below the ground surface (drainage only from the top).

Flow vectors in high perme-ability sand layer under-neath 3D embankment model, transient analysis

Loading

Many different types of loading can be modeled in

RS3 including:

• In-situ field stress (constant or gravitational)

• Distributed loads or surcharges• Concentrated loads (line or

point)• Seismic load (pseudo-static)• Springs

Field stress dialog, gravity option

Verification of Boussinesq solution for vertical distrib-uted load

Loading

Clockwise from top left:

Circular footing on Mohr-Coulomb material

Strip footing on Mohr-Coulomb material

Load properties dialog

Seismic load dialog

Meshing

RS3 uses tetrahedral

(4-sided) finite elements

for true 3-dimensional

meshing. Meshing of

the entire model is done

automatically with one

mouse click. You can

choose either 4-noded or

10-noded tetrahedrons,

and graded or uniform

meshing. Additional cus-

tomization options are

available if you need to

refine or customize the

mesh in any areas of the

model.

Mesh quality can

be automatically

checked according

to user-definable

criteria. Mesh view plane through cross-section of open pit mine model

Results and Data Interpretation

After the analysis has been computed, RS3 offers numerous

options for viewing and displaying the results (e.g. stresses,

displacements, strains, flow vectors etc):

Displacement contours on surface of open pit mine

Principal stress distribution along advancing tunnel with liner support Bolt displacements

• Contour results on excavation surfaces

• Contour results on any user-de-fined viewing planes

• Plot results along any lines• Plot detailed support forces and

displacements• Plot differential results between

stages

Results and Data Interpretation

Principal stress contours around twin tunnel excavations

ConsolidationResults

Twin Tunnel(stress field)

Consolidation settlement underneath embankment with drainage

Vertical displacement with time at the center of embankment 3m below the water table (ac-celerated by the vertical drains)

Addition of vertical drains in the 3D model