Limit state design

Why it is used
Limit state design can be less conservative than the more traditional allowable stress design approach.

The limit state design approach differs from that of allowable stress design in the way in which the potential for failure and consequences of failure are evaluated.  Both approaches ultimately result in an acceptable design.

Limit State Design enables the designer to account for the low probability of worst-worst conditions and determine the design required to achieve a satisfactory level of safety.  These safety levels need to reflect a range of issues, including personnel safety, economic factors, public relations and environmental costs.

Limit state design is based on achieving target reliability.  It therefore adopts risk and reliability techniques to assess distributions on loads and strength and consequently define the probability of failure.  The greater the consequences of failure, the higher the target reliability must be.

The need for limit state design is driven by the increasingly difficult technical and economic demands of more challenging fields.

Jee technology and experience
Jee has been working in this field for many years and has accumulated experience and developed technological solutions in the following areas:

• Limit state design equations: developed limit state design equations for various aspects of pipeline design including  impact, span assessment and stability analysis.
• Risk assessment: performed qualitative and quantitative risk assessments.
• Guidelines:  developed limit state based guidelines, published by the HSE, for overtrawlability of small diameter pipelines.
• Risk and reliability methods: familiarity with risk and reliability methods.

What Jee offers
Limit state design is applicable to any stage of a pipeline project.  Jee offers:

• Preparation of limit state design codes
• Development of limit state design procedures
• Qualitative and quantitative risk assessment