BOTTOM ROUGHNESS ANALYSIS

What’s is bottom roughness?

Roughness Bottom Analysis is an analysis to predict the location of span along subsea pipeline after installation or during operation. The criteria of allowable span is divided into VIV (Vortex Induced Vibration) and ULS (Ultimate Limit State or Static Criteria).

Input :

• Pipeline configuration
• Seabed roughness (profile)
• Pipeline heading alignment

Load Case :

• As-laid
• Flooded
• Hydrotest
• Operations

Output :

• Pipeline stress & strain response
• Span length & height
• Pre-lay & post-lay
• intervention assessment

Why bottom roughness analysis is so important?

Without bottom roughness analysis you don’t know how many support (sand bag, grout bag, etc) that you need to rectify of over span. However, it’s only prediction, so you need further inspection to ensure the location of over span.

Source :

https://dyurindatama.wordpress.com/2013/02/10/2d-pipeline-bottom-roughness/

http://www.engr.mun.ca/~spkenny/Courses/Undergraduate/ENGI8673/Lecture_Notes/2009W_ENGI_8673_L17_Bottom_Roughness.pdf