Hi,

I have been working on a job with DNV 1981 guidelines. I have performed the stability analysis for unburied pipeline with DNV 1981 criteria and found out the concrete thickness required is more than 300mm(for 100 yr condition) with which we cannot coat and install pipeline. So we have to trench the pipeline, so can any body tell me how to find out the trench depth (top cover), transition length and trench angle?

Also the concrete thickness required during installation (1 Yr condition) the required thickness is 30mm. So I presume the pipeline should be post-trenched with minimum 30mm concrete thickness. Confirm my understanding?

Please note that end client is not accepting any other codes(DNV RP E305 or DNV RP F109).

Regards,

Rajath