About LimitState:RING

Benefits

Flexibility and Power

• Analyse single or multi-span bridges with no fixed upper limit on the allowable number of spans
• Automatically identify the critical failure mode even if:
  • only a single span is involved
  • sliding is involved
  • modelling multi-ring arch bridges
• Define and solve for multiple load cases
  
• Automatically detect 'passive' pressures - analyse deep and multi-span arch problems without difficulty
• Model the presence of arch backing material

Ease of Use

• Easy to use wizard system for simple and speedy model definition
  
• Modern, intuitive interface with an interactive modelling environment
• Comprehensive library of standard road and rail vehicles
• Property editor allows quick querying and modification of model properties
  
• 3D graphical output for better understanding
  
• Automatic report generation

Specify Local Properties

• User-definable arch and backfill profiles
• User-definable individual block weights, masonry strength, mortar loss etc.

Proven Track Record

LimitState:RING is the product of many years research effort.

• The first version of the software was originally developed as an academic research tool in 1992, with results published in papers in The Structural Engineer and elsewhere
• The first public versions were developed in association with Network Rail
• Later versions were developed for worldwide use in association with the International Union of Railways (UIC)

Technology

LimitState:RING uses the 'rigid block' method of analysis, which idealizes a masonry arch structure as an assemblage of rigid blocks and uses computational limit analysis methods to analyse the collapse state only.

The rigid block analysis method is reviewed alongside semi-empirical and solid mechanics techniques in the key industry report CIRIA C656 - Masonry arch bridges: condition, appraisal and remedial treatment. The report states that the rigid block technique is:

quick and reliable for a significant range of bridge configurations... a very versatile tool...

a significant improvement from basic limit analysis formulations