THE CORRELATION OF EXPOSURE TIME AND CLAYSTONE PROPERTIES AT THE WARUKIN FORMATION INDONESIA

Abstract

The deterioration of claystone material was studied by observing a mine slope after digging. An
understanding of the degradation of material properties based on field characteristics was required for a detailed
slope stability analysis. Experiments were carried out to investigate the correlation of exposure time and the
degradation of the mechanical properties of claystone. The methods used in this research include direct field
observation and measurements taken from samples of claystone. Claystone samples with different exposure
times were obtained from the mine slope face. The exposure time was calculated from the time the slope was
dug (when mining started). Determination of the mechanical properties was conducted using undrained,
unconsolidated triaxial testing and uniaxial testing. Statistical analysis was carried out to determine the
mineralogical homogeneity of the claystone. An empirical analysis was carried out by plotting the exposure
time against the mechanical properties on a scatter diagram. The degree of correlation was one parameter used
to determine the relationship between the exposure time and material behavior. Based on the results of the
research, it is known that the time span of exposure correlates strongly with material properties due to
weathering and degradation. The decline in strength was accelerated after the material is exposed. Strength
gradually decreased to moderate after 200 days of exposure. Furthermore, the mechanical properties of
claystone material will be stabilizing after 400 days. The results of the analysis were very important in
predicting the behavior of claystone with exposure time on a slope.