貓羅溪高細粒料土壤抗液化強度之研究

This study evaluates the liquefaction of the soils of high fines contents in the Maoluo River area of Nantou City. The particle size distribution curves indicate that the fines content of the soil taken under the viaduct of the second freeway is 74% while that taken near the construction office is 48%. According to the USCS, the under-viaduct soil is CL while the soil near the construction office is SM. But based on the result of analyzing the characteristics of the granular materials and the fines, they are the same kind of soil and contain quartz mostly.

In this study, the soils taken from the sites are used to make the hollow cylinder specimens for the torsional shear tests by controlling the dry density of specimens after consolidation. The test results show that the liquefaction resistance of the under-viaduct soil (FC=74%) is higher than that near the construction office (FC=48%), but the relations of the two soils are almost parallel.

Comparison between this study and the previous test results by Chen shows that the correction coefficient Cr between the cyclic stress ratio of cyclic triaxial test and cyclic hollow cylinder torsional shear test is 0.666 which is very closed to the correction coefficient computed according to De Alba et al. (1975) suggested method. Therefore, the sample preparation and testing process of the hollow cylinder torsional shear test in this study is reliable. With the same fines content at 74%, the liquefaction strengths are very much the same for specimens taken under viaduct and near the construction office.