Projects : Geohazards Evaluation of MEDGAZ Gas Pipeline
(From Algeria to Spain)

The Medgaz Pipeline will cross the Mediterranean Sea in water depths up to 2,160 meters between Beni-Saf, Algeria and Ramblas de Morales, Spain. The pipeline route, and crosses a number of faults and submarine landslides. D’Appolonia, a Dynamic Power Technologies Group company, was responsible for the geohazard evaluation for this project; the primary technical issues included:

• Seismic hazard
• Fault rupture hazard
• Landslide risk

The evaluation provided the basis for selecting a route that minimized geohazard risk, particularly in continental shelf break slope areas.

A number of faults are present along the pipeline corridor. Local faults may control seismic design criteria and may be important for both surface rupture hazard and as a triggering mechanism for slope failure. A detailed review of the geophysical data was used to identify the presence of potentially active faults along the route. Estimates of the time of last movement of the faults were based on the seafloor sediment drape covering recent offsets.

The most significant geohazard identified is the potential impact of submarine landslide runouts on the pipeline. A geomorphologic evaluation of existing landslides along the corridor was performed to identify critical failure modes, slope angles, and runout distances. Geotechnical analyses were then performed to provide quantitative estimates of the factor of safety of the submarine slopes under both static and seismic conditions.

Landslide complex in the vicinity of the pipeline route