This paper discusses the behavior of submarine pipelines and that of the seabottom under anchor impact loads. The laboratory test, in the large scale loading equipment vessel, was carried out in order to study these behaviors.
　Earth pressures, ground pore water pressures, and pipe strains were measured when the steel pipe, in the sand, was under the impact load of model anchors.
　The authors carried out the theoretical calculations of the stress of the buried pipe, and compared their results to the results from the laboratory tests.
　The followiong were found: the penetration depth of the model anchor depends on drop height, weight per bottom area of model anchor, and coefficient of subgrade
reaction of the ground. The value of the coefficient of the impact load of anchors is far larger than that of the coefficient used for buried pipelines on land. Axial stress occurring in the steel pipe can be calculated by the method of a beam on an elastic ground, and circumferential stress can generally be calculated by Spangler's formula.