A higher standard of bridge design
Staged Construction Analysis for Cable Stayed Bridges
that high-end bridge engineers need to increase the efficiency of cable force tuning process while reflecting critical engineering issues realistically
Issues in handling cable-stayed bridges’ staged construction analysis
The cable-stayed bridge is one of the most aesthetic and efficient bridge types for water crossing. However, it is infamous for its resource-taking process for analysis and design, especially the cable force tuning process. This process requires engineers to perform numerous runs of analysis after each adjustment of cable force/stress. Due to the nature of cable bridges, 3D model of a cable-stayed bridge is often very large and composed of a great number of elements and DOFs. This results in wasting many hours of high-end engineers’ hours of time for manual iteration process.
What highly-skilled engineers need is to automate majority of cable force tuning while considering complex engineering issues like numerous stages, multiple tensioning, time dependent creep and shrinkage properties, and geometric nonlinearity (large displacement/catenary).
Process and features helpful for checking constructability of Suspension Bridges
Significant Features and Differences in Results
- 1. Composite Section: Reduce # of DOF to less than ½, Reduce analysis run time to ¼
- 2. Reducing analysis run time is crucial for performing automatic cable optimization
- 3. Cable optimization that can consider:
- - Starting with just unit pretension force
- - Develop construction stages (CS analysis considered for cable optimization)
- - Consider multiple stressing of cables
- - Creep and shrinkage nonlinear time-dependent material property.
- - Nonlinear large displacement effects
- - Performing iterations automatically and minimally
TESTIMONIAL
My presentation demonstrates two case studies off cable-stayed bridges which have composite deck structures. The two bridges have different scales, which is good to describe the varying levels of analysis possible in midas Civil.
Craig SchaPer Associated Engineering, Burnaby BC
I used midas Civil for overall analysis and stage checking. For more detailed checking, I exported midas Civil grillage model to midas FEA as a shell model for more detailed checking and load rating in transverse direction of extradose cable-stay bridge.
Daniel Mariscal AECOM, Tampa, FL
