... frictional. Suction at pile point is usually not considered, and the tensile pile capacity is calculated assuming drained conditions. Depending on the breakout velocity a transient state between drained states (no suction at all) and entirely undrained failure can be defined, and increased breakout capacity...

... Pipe surface roughness Submerged pipe weight history Breakout velocity Vertical displacement The soil resistance was measured during displacement controlled simple breakout. Although thermal expansion in-situ occurs due to force build-up, displacement controlled tests were run to ease test data...