Effect of circular cavity on maximum equivalent stress and stress intensity factor at a crack in buried pipeline

The effects of cavities on maximum equivalent stresses of buried pipelines are investigated in terms of two factors such as size and location of the u nderground cavities by using a finite element code. It has been found that the cavities affect maximum equivalent stresses of buried pipeline signific antly in case that the diameters of cavities are larger than that of the pi peline. The variation of the stress intensity factors for a crack existing on the buried pipeline nearby cavities is also studied. The mode II stress intensity factor, K-II, for a tilt crack located at the top portion of a bu ried pipeline is found to be influenced significantly regardless of the loc ation of the underground cavities.