Definitions 



Soil response to a change in the applied stress field may be 

 ideally divided into two components: consolidation, involving soil 

 element volume change under hydrostatic stress; and shear deformation, 

 involving soil element shape deformation with no accompanying volume 

 change. (The term ''element'' refers to an assemblage of soil particles 

 and associated pore fluid.) 



Consolidation is, by convention, further divided into three components 

 of volume change: an initial component due to the compression of 

 the gaseous phase in the soil voids, termed immediate compression; an 

 intermediate component governed by the hydrodynamic lag of the 

 soil pore fluid in exiting the soil mass, termed primary consolidation; 

 and a final component governed essentially by a relaxation of interparticle 

 bonds, whatever may be their nature, and slight slippages and dislocations 

 of particles in the soil structure, termed secondary consolidation. 



Idealized soil shear deformation or volume deformation without 

 volume change, is generally characterized by a non-linear stress- 

 strain response during which time the soil particles are rearranging 

 themselves in response to the applied stress field. Failure in 

 shear is identified by the occurrence of a peak shearing stress 

 condition or by the occurrence of excessive shearing deformations. 

 However, even when the application of the shearing load to the 

 soil element is halted prior to failure, relaxation of interparticle 

 bonds and reorientation of particles will continue, manifested 

 as soil element deformations at decreasing, constant, or increasing 

 rates. This time-dependent soil shape deformation, without volume 

 change, under constant shearing load is termed shear creep. 



Previous Examination 



Most seafloor sediment examination has been confined to the 

 measurement of bulk wet density, grain size distribution, specific 

 gravity of the grains, Atterberg limits, carbonate content, organic 

 carbon content, color, odor, and a strength index [5-8]. Several 

 investigations have been performed to define the consolidation 

 characteristics of calcareous oozes, but these have not evaluated 

 the secondary consolidation characteristics [9-12], and further, 

 the sediment involved in some of these is believed to be [9, 11, 

 12] a precipitate, not an organic construction. Only one in-depth 

 study of consolidation, including secondary consolidation, of a 

 ''deep-sea sediment'' is known [13]; that sediment was probably 

 terrigeneous in origin and contained little calcareous material. 

 No study of shear creep deformation behavior of a deep- ocean sediment 

 has been published. 



