Failure of a soft cohesive soil subjected to combined static and cyclic loading

This paper describes the type of failure that a soft cohesive soil can exhibit when acted upon by combined static and cyclic loading. The conclusions are based on the results of a comprehensive experimental research in which, in addition to identification and classification testing, 15 monotonic simple shear tests and 138 cyclic simple shear tests were carried out in which, prior to the cyclic shear stresses, different levels of monotonic shear stresses were applied. Laboratory tests were performed on undisturbed samples taken from the southern area of the port of Barcelona, Spain. In general, the results thus obtained indicate that the undrained shear strength for a given number of cycles is clearly affected by the initial shear stress, as it is explained in this paper.