VERIFICATION OF DRYING SOIL-WATER CHARACTERISTIC CURVE (SWCC) ON LOW MATRIC SUCTION VALUE FOR CRUSHED COMPACTED CLAY SHALE IN CISOMANG REGION

• Main Author: Nada Kamilia, Huriyah
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/68099
• Institution: Institut Teknologi Bandung

Clay shale become an interesting problem because of the relationship between the behavior of the soil to saturated and unsaturated conditions. Unsaturated soil conditions are related to the matric suction values which is known based on the Soil-Water Characteristic Curve (SWCC). One of the ways to measure SWCC is the filter paper method. The test is carried out by placing the filter paper in direct contact with the soil until the equilibrium of the matric suction value between the soil and the filter paper is reached. ASTM D5298-16 proposes that matric suction for soil by using filter paper requires a minimum of 7 days to reach equilibrium. The test was conducted to determine the equilibrium time of filter paper measurement for clay shale at low matric suction values (25% and 30% water content). The results of testing in the laboratory obtained that the equilibrium time at 25% and 30% water content was 21 days. The results of the analysis using the numerical program, SEEP/W obtained that the equilibrium time at 25% and 30% water content was 27 and 29 days, respectively. Verification of drying SWCC was carried out from the results of previous studies when the water content was 0% to saturation. The Fredlund-Xing equation (1994) was used to calculate the SWCC fitting. The results of the SWCC fitting parameters in the gravimetric water content parameter obtained values of a = 1000, m = 0.7, n = 0.7. SWCC fitting parameters in volumetric water content parameter obtained values of a = 1000, m = 0.3, n = 0.9. Parameter fitting SWCC in the degree of saturation parameter obtained values of a = 251188.7, m = 9.8, n = 1.5. Indirect calculation method of permeability function when matric suction 0.01 kPa to 706964.13 kPa obtained fitting parameters, which are a = 300, b = 1.5, and c = 5. The results of SWCC fitting in the degree of saturation parameter produce air-entry value (aev). The air-entry value is obtained at the matric suction value of 13100 kPa.