Quantification and Assessment of Soil Structure and Rate-Dependent Consolidation Behavior of Natural Clays Using Developed Automated Rowe Cell

Abstract

An automated Rowe cell testing system was innovatively developed that consists of modification of a standard Rowe cell including employment of additional necessary instrumentations such as upgrading and adaptation of controller hardware and development of controller program to optimize device performance and precision during long test durations. Considering advanced structure of controlling software, development of essential algorithms and subfunctions to administer different test phases of consolidation test process including initial saturation, controlled gradient, and constant rate of strain required multiple series of tests for validation of system automation as well as verification of operational performance and accuracy. All issues were accomplished successfully through precise implementation of a comprehensive experimental program to explore and assess soil structure of natural clays, and hence, to quantitatively evaluate impact of structure on resulting rate-dependent/independent consolidation behavior. In this way, the behavioral differences developed in rate-dependent consolidation were associated with degree of clayey soil inherent structure characteristics, and thus, verified by means of presented engineering framework. Additionally, those ratedependent differences in consolidation behavior were then quantified using structure properties of clayey soil as a result of developed quantification methodology based on a numerically computed parameter; structure number (SN) (i.e., quantifying all facets of composition as well as history of soil). In this scope, it was explored that Samsun-Carsamba Blue Clay (Shallow) possessing a medium high degree of structure presented a SN value of 2.84 while Samsun-Carsamba Blue Clay (Deep) having a moderate degree of structure displayed a SN value of 2.48. Further, Mugla-Koycegiz Clay (Shallow) possessing a high degree of structure showed a SN value of 3.49 while Mugla-Koycegiz Clay (Deep) having a medium low degree of structure demonstrated a SN value of 2.19. Moreover, Afyon-Alanyurt Clay (Shallow) possessing a very high degree of structure provided a SN value of 4.40.