Bridging The Gap Between Technology And Engineers

In India, the field of bridge engineering has undergone significant evolutions in recent years, reflecting a blend of tradition and innovation. With a landscape dotted with rivers, mountains, and diverse terrains, the demand for robust and efficient bridge structures has never been greater.

Recent developments in bridge engineering in India have seen a shift towards sustainable and resilient infrastructure solutions. The adoption of innovative construction techniques, such as precast segmental construction and incremental launching methods, has accelerated project timelines and minimized disruptions to the surrounding environment

Introduction of CSi Bridge

Developed by Computers and Structures, Inc., CSi Bridge offers comprehensive capabilities for engineers to simulate and evaluate bridge performance under various loading conditions. With its intuitive user interface and advanced modelling features, it enables engineers to efficiently create 3D bridge models, perform sophisticated structural analysis, and generate detailed design reports. The software also supports a wide range of bridge types, including concrete, steel, and prestressed bridges while incorporating relevant Indian Road Congress design codes. This allows for efficient analysis of factors like weight loads and stresses, leading to safe and optimized bridge designs across India's infrastructure projects.

CSi Bridge: Know its Significance & Loading Patterns

CSi Bridge stands out as a powerful software program specifically designed to streamline and enhance the bridge design process, bridging the gap between complex engineering principles and practical application. It empowers you to design safe, efficient, and compliant bridges while streamlining your workflow and fostering collaboration. If you're a bridge engineer in India, CSi Bridge is a valuable asset to have in your design toolbox and below are a few reasons why:

• The Bridge Modeler enables the parametric definition of girder-type bridge systems. Users initiate high-level parametric modelling by defining span length, layout lines, cross-section, and other geometric and structural specifications. The Bridge Modeler then assembles frame, shell, and solid objects, and connects them with link elements, to automatically create bridge objects. It expedites design by automatically generating, meshing, and analysing complex bridge models. Templates are also available for several superstructure and substructure design checks.
• In this software, Rail Structure Interaction is available in an automated manner to define rail support nonlinear parameters by the user. It helps to determine whether the rail supports are loaded or unloaded. For RSI analysis, no separate modules are required.
• Bridge Engineers engaged in the analysis and design of cable bridges, which can use Csi Bridge for working out cable loads to achieve the desired bridge deck profile under a user-defined load using CSi Load Optimizer.

The power of the SAPFire analysis engine is fully integrated into the CSi Bridge, with an ultrafast multithread solver that uses all available cores for faster analysis. The advanced options include

• Staged construction
• Creep and shrinkage analysis
• Cable tensioning to target forces
• Camber and shape-finding
• Geometric nonlinearity (P-Delta and large displacements)
• Material nonlinearity (superstructure, bearings, substructure and soil supports)
• Modelling of discretely nonlinear objects like dampers and isolators with options for buckling static, multistep static, influence line and other kinds of linear as well as linear dynamic analyses.

1.Dynamic Vehicle Loading in CSi Bridge

Bridges are designed to handle static loads, but real-world traffic introduces dynamic effects. These dynamic vehicle loads cause the bridge to vibrate and experience higher stresses than the weight of the vehicle alone.

CSi Bridge offers a state of art moving load analysis option where the user can define multiple instances of a single vehicle acting on a single lane or rail track that can be combined in a multi-step load pattern, allowing for complex patterns of loading. For each instance, the vehicle can move forward or backward with a specified starting location, starting time, and speed.

Furthermore, a moving load analysis can be converted into a Direct-Integrated-Time-History Analysis to capture the step-by-step response of the structures to seismic ground motion and other types of loadings such as blast, machinery, wind, waves, etc. Analysis can also use modal superposition and both can be linear or nonlinear.

 

 

 

 

2.Influence-Based Moving Load Analysis

Analysing moving loads has been made easier and more efficient for the user. Lanes are available through the bridge modeller to indicate where the vehicle loads act on a bridge superstructure. Lanes are defined by reference lines and enable the modelling of complex roadways and traffic patterns. Users can also create multiple lanes, straight or curved, each of a specific length and width.

 

 

Key points of Influence-based moving load analysis:

• The moving load analysis can be selected as the load case which can be implemented as an influence-based enveloping analysis.
•  In this analysis, vehicles (oriented in either direction) are automatically positioned within each lane both in transverse and longitudinal directions to induce both maximum and minimum response throughout the structure.
• It lets the users decide whether to include directional factors such as Vertical, Braking/Acceleration and Centrifugal while defining the load case.
•  An influence surface is generated for a specific point along a structure subjected to a moving load, where the variation of a given response quantity (axial, shear or flexural force, reaction, etc.) at that specific point is plotted as the moving load travels across the surface.

How CSi Bridge Simplifies Structural Engineering?

Interactive database editing allows you to edit model data in a table view, simplifying the task of making changes to the model. Tables are easily exportable and importable from Microsoft Excel and Microsoft Access.

 

 

Layout Lines:

Layout lines define the roadway layout of the bridge. They can be defined within CSi Bridge using bearing and station notation or PI (point of intersection) inputs. 

They can be imported using a LANDXML file. As layout lines are modified, the entire bridge structure and its parametric geometry are updated.

Parametric Variations:

Using parametric variations, variations in the deck section dimensions that include girder spacings, deck and overhand widths, depths and more may be applied to the bridge model. Defining variations parametrically significantly reduces the amount of time to model a bridge.

Post-tensioning:

Define post-tensioning in CSiBridge using the refined options for laying out tendons and forces. When defining box girders, CSiBridge will automatically assign the drape locations within the tendon, or the engineer can edit them as well. Tendons can be completely auto-generated for segmental bridges.

Section Designer:

Section Designer is an integrated utility, built into SAP2000, CSiBridge and ETABS, that enables the modelling and analysis of custom cross sections. Section Designer is useful for the evaluation of member properties and nonlinear response, including nonlinear hinge and PMM-hinge behaviour.

Tendon Element:

Tendons are drawn easily as independent objects, with geometry specified as straight lines, parabolas, circular curves or other arbitrary shapes. Tendon loads, including all losses, are defined easily in CSiBridge. Tendons can also be added to bridge spans and girders using template profiles that can be edited easily. Tendons may be considered as elements or loads.

Define specific loads to model using a wide array of loading conditions with CSiBridge built-in user loading options. Loads may also be applied parametrically as point, line, area, and wet concrete loads.

Use CSi Bridge to Redefine the Analysis and Design

CSi Bridge has been crafted with keeping the user’s convenience in mind. The aim is to increase the efficiency and develop a smooth communication between the user and the software. CSi Bridge has redefined the way we analyse and observe the results.

The user can conduct any kind of analysis including static, staged construction (shown below), multi-step static, modal, response spectrum, time (response) history, moving load, buckling, steady state and much more.  The user has complete control over the bridge model and can analyse it accordingly.

Staged Construction:

Staged construction is a type of nonlinear analysis in CSiBridge that allows you to define a sequence of stages wherein you can add or remove portions of the structure, selectively apply loads to portions of the structure, and consider time-dependent material behaviour such as ageing, creep, and shrinkage.

Creep and Shrinkage:

Long-term deflections due to creep and shrinkage can be computed along with staged sequential construction analysis. Time-dependent material properties are based on CEB FIP, ACI 209R, Eurocode and other codes or user-defined curves to compute creep strains.

Design fully integrated with the analysis process and includes design options for concrete box girder bridges, multicell box girder bridges, concrete slab bridges, concrete T-beam, steel I-girder and steel U-girder with composite slab bridges and design combinations defined by the program automatically. Furthermore, the user can define new design combinations or edit the ones available.

This is just a gist of what the software can do. Overall, CSi Bridge is a powerful software program that streamlines the bridge design process in India by providing a user-friendly interface, robust modelling features, and integrated analysis capabilities. It is an essential tool for bridge engineers designing safe and efficient bridges for India's infrastructure.

CSI Engineering Software Private Limited is the exclusive channel partner of Computers and Structures Inc., Walnut Creek, USA in India, Nepal and Bhutan. We will not only provide you with industry-leading software but also extraordinary customer support for all your problems.