Data acquisition and analysis system for the application of triaxial test and direct shear test in determining the residual shear strength of clays from landslide site

Scope and method of study. The objective of this research is to develop a data acquisition and analysis system for determining the residual shear strength of clays. Instrumentations of the system is done through the modifications on the triaxial test and the direct shear test machines. A computer package is developed on an IBM PC for data acquisition and analysis. Janbu's Method is used in this research for slope stability back-analysis on the landslide profile. Three different sample preparation methods, which represent different degree of disturbances, are used in the laboratory tests. Seven different soil profiles are used in the slope stability back-analysis.;Findings and conclusions. A landslide case in northeastern Oklahoma has been analyzed using the developed system. Through the comparison between the results from laboratory tests and slope stability back-analysis, the data acquisition and analysis system demonstrates its validity in the application of residual shear strength measurements. Residual shear strength obtained from the R/R-Bar triaxial tests showed good coincidence with the slope stability back-analysis. The developed data acquisition and analysis system is ready to be used for further residual shear strength measurements and slope stability design.