ABSTRACT
This study is concerned with the investigation of strain-rate effects on shear strength characteristics of saturated compacted Fadama Clay. The experimental program consisted of consolidated undrained triaxial test with controlled strain-rate. The rates of strain adopted are 0.0024, 0.006, 0.012 and 0.03 in/min. (0.08, 0.2, 0.4 and 1.0 %/min., respectively). This study mainly attempts to focus attention on strain-rate effects on rate of strength increase with respect to faster rates of deformation, strain at failure, pore pressure development and strength parameters. A mathematical equation is derived which best represents the relationship of the above parameters and rate of strain. In the analysis of test results, a direct functional relationships such as (1) strength increases with increasing rate of strain, (2) strength decreases with increasing time to failure, (3) failure strain increases with increasing rate of strain, (4) pore pressure increases with increasing time to failure and (5) pore pressure decreases with increasing rate of strain were obtained. A .simple method of Rate Process Theory is described using Scott and Ko method (1968) for various cell pressures of 10, 30 and 45 psi. (68.95, 206.85 and 310.28 kN/m2 ). The method used in the determination of the mineralogy of Fadama Clay is also described. Observations obtained in this study point to the fact that the properties of Shika Fadama Clay can be improved under proper conditions of compaction.