Use of Flow Pump Method forSoil-Water Characteristic Curve Measurement

• Main Authors: Yung-Wen Chen, 陳湧文
• Other Authors: 葛宇甯
• Format: Others
• Language: en_US
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/tm2fd7

碩士 === 國立臺灣大學 === 土木工程學研究所 === 105 === In unsaturated soil mechanics, the soil-water characteristic curve (SWCC) represent the relationship between soil suction and soil water content. SWCC is an essential constitutive relationship for solving geotechnical engineering problems, such as slope stability, retaining walls and collapse of surface soil due to rainfall infiltration. Over the past few decades, many standard tests have been developed to evaluate and determine the SWCC. Among them, the ASTM pressure plate method has been widely used due to its convenience and reliability. However, it is difficult to determine if the specimen reaches the steady state because the only way to evaluate is observing its drainage condition. It causes the experimental duration too longer, approximately one to three months to obtain a SWCC. The flow pump method, proposed by Olsen in 1966, controls the flow rate of water entering or leaving the specimen. This method has been applied to measure SWCC in past few years. In particular, it is capable of obtaining continuous drying and wetting curves. In this study, the remolded kaolinite clay was selected to conduct the permeability test, where the performance of the flow pump is verified. Flow pump system, triaxial system, 3D printing technology, axis translation technique and modified suction drop method were put together to establish an SWCC measurement system. Fine quartz sand was used as test material for this research. Results showed that this experimental system is capable of determining the drying SWCC efficiently, costing less experimental time.