Even with the frame analysis program Superstress, the application of highway or railway loading to a bridge structure can be a time-consuming and laborious task. But H-load provides the solution; having set up the grid or space frame using the data generation facilities of Superstress, H-load allows the engineer to define the deck, lanes and loading quickly and accurately. Trains of loads can be easily moved along the lanes at user defined intervals. A sophisticated 32 bit generator then disperses the loads to the members, or joints if specified, of the underlying structure to produce Superstress load cases.

The suite is further enhanced for those engineers involved in multiple span bridge design or assessment by the inclusion of Autoloader. This will accept influence surfaces generated using Superstress for a given location on a deck or sub-structure, and will then calculate the worst loading positions for the required effect. These loads are then transferred automatically to H-load, ready for dispersal to the underlying structure. Both UK and international loading codes are addressed. Finally the Superstress grid analysis results can be processed by W-armer to give reinforcement design moments in both primary and secondary directions for the provision of top and bottom steel.

FEA has launched version 13.3 of its Lusas Bridge software for Windows NT, which provides engineers with analysis and assessment facilities for all types of bridges. Fundamental frequency, seismic, dynamic, large deflection and fatigue analyses can be performed on simple grillages through to complex cable stayed and suspension structures.

This latest version extends the modelling, analysis and results processing capabilities of the software, and enables users to further customise and integrate Lusas Bridge into their working environment to meet their company's specific requirements.

Enhancements in version 13.3 of Lusas Bridge include an all-new wizard for grillage analysis; additional material libraries; enhanced standard section libraries; a section property calculator; improvements to the vehicle loading optimisation; vehicle loading to Swedish design code BR094; an abnormal indivisible vehicle load generator; a new moving load generator; and a Smart Combinations facility which automatically chooses the appropriate adverse or relieving factor for a particular load combination for a selected design code.

Norconsult has developed a PC- Windows design package for bridge design known as Norconsult Bridge Design which has been used on a series of projects including design of a bridge in Greece at Egnatia Odos. General purpose finite element model-code Abaqus/Standard from software company Hibbitt, Karlsson & Sorensen is used as solver and a finite element model 'engine'. The basis of the program is a graphic user interface, which allows the user to build up a true three dimensional model of the bridge and its components, and to visualise all items on the finite element model.

This program can be used to develop a three dimensional model of a bridge, to describe and calculate construction phases, deflections and prestressing, to assess wind loading and response, to implement traffic loading and combinations of loads, to estimate earthquake impact or to simulate the response from extreme loading.

Non-elastic response, either from wind loading during construction or seismic loads, can be studied by simplified time series. The general and advanced material models in Abaqus for concrete may then be used. NBD is designed for Windows platforms and can communicate with Abaqus installed on all platforms; communication over a local area network or the Internet can also be established. The software system is capable of project management, if more than one designer is involved. Besides the effective photo realistic visualisation tools, a configurable report generator eases the task of project documentation. NBD can analyse static and dynamic loads through Abaqus.

The philosophy of the program is that all types of calculations shall be at hand in one suit of programs. Hence it is the same model that is used, regardless of the type of calculation, and it is not necessary to build up a new model each time. The geometry can be exported to Cad systems such as Autocad and Microstation. It is also very easy to perform animations or to show pictures of the bridge in true environments in a very early stage of the design.

A new software package claims to solve one of the most serious problems faced by bridge designers. Bridge codes require designers to identify all arrangements and combinations of vehicles giving the worst effects on all parts of the structure. Working with the Strap structural analysis program, Autobridge automatically generates the considerable number of vehicular load-cases required, saving many hours of the designer's time.

Vehicle loadings are held in a library but may be modified on application. For the UK and other markets using British codes, the required loaded length and intensity modifications are automatically applied in accordance with BD37/88. On multi-lane bridges, all permutations of lane occupancy may be considered.

The program calculates the maximum and minimum results for each structural effect at each point on the bridge. Vehicular load positions, UDL intensities and loaded lengths may be viewed together with influence line diagrams. Autobridge integrates into the recent version 8.00 of Strap, which has many features for bridge designers. Autobridge, priced at £995, is available from GTS Cadbuild in the UK/Europe and from distributors around the world.

Version 7.2 of finite element analysis software Diana Analysis (below) has just been released. It has many new features and improved capabilities, including a general body and tetrahedral meshing, dynamic filos file. In addition to these features, further integration with the Diana pre- and post-processor has led to a product which is easier to use, the company claims. A new liquefaction module is also available in Diana 7.2 - a facility added in response to Japan's 1995 earthquake in Kobe, which showed the destructive effect of soil liquefaction. A model was developed based on the Arbitary Lagrangian Eulerian method, where the material is flowing through the mesh. Micro-Diana is one of the newest products from the company. It is a complete finite element program and is also provided with the integrated pre- and post-processor. Besides generating the mesh, it is also possible to define materials, geometry, boundary conditions and loads. The post-processor enables the user to easily assess the results of analyses. Results of displacements, stresses and strains are presented numerically as well as in contour plots, vectors and graphics.

Micro-Diana has a modular structure and contains all primary and supplementary modules. These include linear static, eigenvalue, non-linear, dynamics, shock & response analysis, US-subroutines, flow and heat transfer, Euler stability analysis and parameter estimation. With its 300 nodes the program is particularly suitable for smaller but more complicated analyses.

With version 7.2 Diana 2D has also become available - this has all the capabilities and features of Diana 3D and the number of nodes is also unlimited, although the user is restricted to 2D analyses. Functions of the program are X-Y plane, all analysis types and all material models. Element types are 2D beams, plane stress, plane strain and axisymmetric.

Bestech Systems will launch the latest version of its Sam bridge design suite this summer (below) ; it will allow the design and rating of bridges in accordance with a variety of international codes of practice, including AASHTO LRFD, Austroads, and BS5400 specifications. At the heart of the system is a new graphical user interface which enables the engineer to easily transfer critical results from the structural analysis to any of the beam design modules such as steel composite, pre-tensioned, and reinforced concrete beams for code checking. This procedure requires fewer iterations to reach an optimum design solution compared with traditional methods. Firstly the bridge layout is defined using graphical tools for specifying design lines, roadways and sidewalks, span-end lines and support conditions for which fully configurable grillage meshes are produced. The model representing the structure could be a line beam layout or a refined 2D or 3D framework of members.

Sections and beams to represent the structural form are prepared graphically from comprehensive libraries of standard elements. These include facilities for specifying reinforcing bars and pre-stressing tendons. A section editor is also included for generating non-standard shapes. The sections and beams are assigned to members graphically, and all section properties for use in the analysis are calculated automatically.

Predicting critical transient load patterns is automated in Sam by the use of influence methods to generate critical load configurations in accordance with a range of design standards. Libraries of standard vehicles and trucks that can be customised are included.

These critical load patterns can then be combined with permanent loads using intelligent routines for generating loading combinations and envelopes. These resulting load effects, such as bending moments and shear force envelopes with corresponding associated forces are then transferred automatically to the beam design modules.

The load effects produced from the analysis can be investigated graphically within one of the beam design modules for reinforced concrete, pre-tensioned concrete and steel composite beams to many international design standards. A recent addition to the beam modules is the design of steel composite beams to the new AASHTO LRFD specification. It includes facilities for investigating moments (during construction, worst positive or negative cases), shear forces and shear with associated moments.

Having obtained a solution, the engineer decides whether the section or beam is adequate, grossly under-stressed or over-stressed. Further iterations are often required to obtain the optimal solution. This process involves making changes to the bridge parameters such as section or beam data and then reassessing the critical loads until a final design solution is reached.

TDV's new RM2000 software product was used to analyse South Korea's Kwangan suspension bridge, currently being built in Pusan. TDV claims its new program can quickly find a solution for even the most complex structures and loadings. The full analysis of the Kwangan Bridge included large deflection static analysis for all the construction stages, buckling analysis for the pylons and the members of the truss structure, traffic loading analysis - calculation for ten lanes took less than 20 minutes to form the loading envelopes - and Eigen vectors and response spectrum analysis related to the deformed shape.

RM2000 can handle general engineering problems from building frames to guyed masts but is specifically aimed at the bridge engineering market. The new program has special facilities for handling prestressing application where 3-D tendon profiles are defined independently of the model mesh. It can take account of creep and shrinkage effects, even for non-linear structures and can carry out push-over analysis to structural failure. The program is equipped to handle non-linear material, plastic hinges, friction and contact elements. Dynamic time history analysis for mass and load varying in time (for example for moving loads) including viscous damping and non-linear static effects can be accommodated, and the program is design code independent; standard code features are available but can be edited or redefined.

All aspects of the Kwangan bridge for both construction and final stage

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