@article{TonnyLesmana Baskari_Zufialdi Zakaria_Nana Sulaksana_Budi Muljana_2021, title={STUDY ON RHEOLOGICAL CONSTITUTIVE MODEL OF CILILIN VOLCANIC CLAY, INDONESIAIN RELATION TO LONG-TERM SLOPE STABILITY}, volume={21}, url={https://geomatejournal.com/geomate/article/view/27}, abstractNote={<p>: Ground movements do not remain constant over time but it is a time-dependent phenomenon in the form of long-term deformations due to in-situ stresses acting all the time on the slope body. Therefore, the time-dependent behavior of soil mass is an important factor that influences long-term slope stability. To understand the long-term slope stability, research on soil rheological characteristics is required so that the time-dependent soil strength reduction can be known. The result of the research will be very useful for the policymaker in disaster mitigation and regional planning.&nbsp; To determine the rheological characteristics of Cililin Volcanic Clay, a laboratory shear creep test was carried out on soil samples taken from the Cililin area, West Java, Indonesia, which is well known as landslide-prone areas. Fifteen undisturbed soil samples were prepared for laboratory shear creep tests. The level of shear stress applied to the shear creep test is 50% - 95% of the peak strength. Then, the soil rheology constitutive models were established which are used to understand the creep behavior of the soil, determine the soil long-term strength, estimate the reduction of soil parameters as a function of time and calculate long-term slope stability. The result shows that the long-term strength of soil is reduced 48.80% from its peak strength after 16 years. The cohesion and internal friction angle reduced from 44.72 kPa and 30.34<sup>o</sup> become 21.82 kPa and 15.94<sup>o</sup>, respectively, and the slope safety factor is reduced from 2.16 to 1.04. Rheological modeling also shows that slope stability is a function of time.</p>}, number={86}, journal={GEOMATE Journal}, author={TonnyLesmana Baskari and Zufialdi Zakaria and Nana Sulaksana and Budi Muljana}, year={2021}, month={Oct.}, pages={40–47} }