Load types and
LUSAS Bridge provides a
comprehensive range of general loading types to cater for most
circumstances. Vehicle load types, train loading, and prestress and
post tensioning to many international design codes are also provided.
Vehicle load optimisation facilities help find onerous traffic
patterns. Envelopes, basic and smart load combination facilities help
investigate maximum and minimum primary and coincident effects.
General load types
prescribed and thermal loads are feature based loads that are
assigned to the model geometry and are effective over the whole of
the feature to which they are assigned.
- Structural loadings
include gravity, concentrated, distributed, face, temperature,
stress/strain, and beam loads.
- Prescribed loading
options allow initial displacements, velocity or acceleration to
- Discrete loads
distribute a loading pattern over full or partial areas of the
model independent of the model geometry.
- Compound loads (as
used to define load trains) can be formed from a set of previously
defined discrete loads and be asssigned to a model as one loading.
- Thermal loads
describe the temperature or heat input for a thermal analysis or
for a coupled structural / thermal analysis.
- Variations in
loading can be applied to all feature load types according to the
feature on which they have been assigned.
Prestress and Post Tensioning
Single and multiple
tendon prestress wizards calculate equivalent nodal loading due to
tendon prestressing or post-tensioning and assign these forces
automatically to the elements within a model. Computation
of tendon forces can be carried out in accordance with
AASHTO-LRFD, Eurocode EN1992, China JTG D62-2004 and other design codes.
- Tendon profiles can be defined
in 3D space or in two 2D planes, to suit local practice, and can be viewed in real-time as
they are defined.
- The ability to input many hundreds of
tendons in one analysis that can be assigned to many hundreds of
loadcases is made easy by the use of the multiple tendon prestress
wizard. Through a series of dialogs, the wizard simplifies the
definition of tendon profiles and properties.
- Elastic shortening losses can be
specified for multiple stressing stages – useful for staged
construction. Locally defined tendon profiles can be used anywhere
in the model and any number of times. Tendon material properties including short and long term losses can
- The tendon can then be easily assigned
to one or more line features on the model and, more importantly, to
one or more loadcases at the same time.
- Tendon profile data can be
tabulated for a defined spacing along a beam and with reference to
vertical and horizontal origins.
loading facilities in LUSAS Bridge software make load generation
straightforward, significantly speeding up the task of defining the
loading on a bridge deck. They comprise:
- Static vehicle
- Train loading
- Load trains
- Abnormal loading
- Moving load
- Vehicle load
Static Vehicle Loading
Static vehicle, lane, and knife edge loading
types are provided for many international bridge design codes. These
- AUSTROADS Bridge Design Code
HB77.2, AS 5100.2-2004, AS 5100.7-2004. (Australia)
- Canadian Highway Bridge
Design Code (CHBDC.)
- JTG D60-2004 General
Code for Design of Highway Bridges and Culverts. Peoples Republic
- Special vehicles defined as
Load Model 3 (LM3) in the Danish National Annex to EN1991-2
- EN1991-2:2003 Eurocode 1:
(Eurocode) including any country-specific load models as part of a
country's National Annex to the code.
- TIEL 2172072-99 and the
National Annex EN1991-2 (Finland)
- IRC:6-2000 Section: II Loads
and Stresses. (India)
- Israeli loading design code.
- Korean loading code
- NATO vehicle loading defined
in annex A of STANAG 2021
- New Zealand loading code
- Norwegian loading design code
- Poland loading code
- TMH7 Code of Practice for the
Design of Bridges and Culverts
- BRO Classification loads
- BS5400, BD37/88, BD37/01,
BD21/97, BD21/01, BD 86/11 and EN1991-2 National Annex 2.16
LFD and LFRD loading, and selected state dependent design loading
- Additional loading types are being added all the time.
Train loading options for many international bridge design codes
including AASHTO and Eurocode are provided.
- Load trains can be
created using a compound load facility.
- Abnormal load generators
Moving load generators
- Static vehicle and train
loadings can be used either on their own or with a moving load
generator to automatically create the required set of loadcases as
a loading type makes its way across a bridge.
Significant amounts of
time can be saved with the Vehicle
Load Optimisation software option, which generates the most adverse
combination of live loading for a chosen design code. The interface consists of a series of
dialogs requiring only the input of a few parameters to enable an
optimised load pattern to be generated for line beam or shell/plate
element models. Use of
vehicle load optimisation leads to more efficient and economic design,
assessment or load rating of bridge structures.
Envelopes and combinations
A key feature of LUSAS
Bridge is the
Basic, Smart and Code-specific load combination facilities which allow manual or fully
automated assembly of design load combinations. From these, envelopes, contour and
deflected shape plots, and results graphs can be readily obtained for any loadcase under
- Basic load combinations allow for manual definition of loadcases and
- Envelopes of multiple
loadcases create maximum and minimum results.
- The Smart Combinations facility
automatically generates maximum and minimum load combinations from the applied loadings to
take account of adverse and relieving effects. This enables the number of combinations and
envelopes required to model a bridge to be substantially reduced. Absolute maximum
envelopes are included.
- Load Combination Wizards use predefined bridge load
cases for country-specific design codes and help
automate the definition of load combinations for bridges. When used in conjunction with a
design code template, combinations of load combinations are automatically created to give
the resultant maximum and minimum ULS or SLS loadcases.
Load combination wizards
Predefined bridge loadcases for
design codes help to automate the definition of load combinations.
When used in conjunction with a design code template, combinations of
load combinations are automatically created to give the resultant
maximum and minimum ULS or SLS loadcases.