Mechanical behavior of intact and remoulded calcareous silts

Calcareous silts are encountered in many offshore areas where oil and gas exploitations are taking place (e.g., Arabian gulf, south east of Brazil, south east and north west of Australia). Understanding behavior of calcareous silts remains challenging as undisturbed silt samples are difficult to obtain, and most studies rely on remoulded silt samples. The purpose of this paper is to characterize the mechanical behavior of intact and remoulded offshore calcareous silts from two different water depths. The comparisons are done based on microstructure characterization using scanning electron microscopy (SEM) images supported by index tests, one-dimensional compression tests and undrained monotonic triaxial tests. The results have shown that, except for the critical state friction angle, the behaviour of remoulded silts differs from that of intact silts, due to the change in microstructure, which appears to be more compact with less intact open shell particles.

Presenter

Andrew Lim
PhD (Geomechanics), BEng Hons (Civil)
Graduate Consultant (Mine Waste)
Email

Andrew Lim is a graduate engineer with experience in geotechnical engineering, soil mechanics, advanced soil experimental testing, numerical modelling and site investigations. Since joining SRK, he has worked on projects in Asia, Southern Africa and Australasia related to hydropower dams, waste rock dumps and tailings storage facilities. His engineering experience includes interpretation of geotechnical parameters, slope stability assessment, seepage modelling, cost estimation, tailings deposition strategies and landform evolution modelling (LEM) for closure studies. His post-graduate education background relates to developing a large-scale physical model to study soil behaviours, site-investigation using various soil sampling techniques and interpretation of geotechnical parameters from an advanced soil apparatus.