Experimental studies of the long-term deformability of clayey soils: Fid-Bau Portal

Experimental studies of the long-term deformability of clayey soils

Petrakov, A. A. / Makienko, V. E.

Conclusions 1. Standard methods of determining the strain characteristics of a soil, e.g., GOST 12374-66, do not make it possible to evaluate to the fullest extent their yielding properties, which are governed by the rheological character of the deformation. 2. The strain characteristics of soils (overall-compression modulus, stiffness coefficients of the foundation bed), which are determined from soil tests conducted in accordance with GOST 12374-66 may exceed their limiting long-term values obtained with consideration given to rheological properties by several factors (in our case, by a factor of 3.4). The use of stiffness coefficients on the high side for the design of buildings raised on nonuniformly deformable foundation beds (underexcavated sites, soils prone to slump-type settlement) leads to overdesigned structures. For these cases, therefore, it is recommended that the rheological characteristics of the soils be determined experimentally. 3. For comparability of the rheological characteristics of soils determined from plate tests and on small specimens, it is necessary to assign consistent criteria for displacement stabilization, e.g., criteria that are interrelated over the depth of an equivalent layer.