Summary: | 碩士 === 國立臺灣科技大學 === 營建工程系 === 103 === Lateritic soils are widely distributed in western Taiwan, and most of them are under unsaturated condition. Therefore, the traditional saturated soil mechanics cannot fully explain the behavior of complex unsaturated soil. The objective of this research is to study the characteristic of apparent cohesion and suction of unsaturated compacted lateritic soil. This study conducted pressure plate test, unsaturated triaxial suction test and filter paper test to assess the characteristic of matric suction using unsaturated compacted lateritic soils from Linkou. The relationship between matric suction and apparent cohesion was established through saturated and unsaturated triaxial tests under extend Mohr-Coulomb concept. However, the unsaturated triaxial test is difficult to conduct and not easy to use in engineering application. Therefore, this study also used the results from UC test to estimate the apparent cohesion under Specified drying and wetting path. Test results show that the apparent cohesion was overestimated using UC test result. Hence, it was modified by pore air pressure at failure, and compare with unsaturated triaxial test result. The results show that the modified apparent cohesion is similar to the apparent cohesion determined from unsaturated triaxial test. However, further study is warranted.
|