Centrifuge Tests for Artificially Cemented Clay Slopes

摘要

Static and/or cyclic softening and strain localization of sensitive clay are of great importance in the stability of coastal and submarine slopes or levee embankments. It is important to know the difference between static and dynamic failure mechanisms because the thickness of shear band affects how fast strain is localized. Total of 7 centrifuge tests were performed for the artificially cemented sensitive clay slopes. Four tests were high plastic San Francisco Bay Mud (SFBM) models with cement mix ratio of 3 to 5%. The others were low plastic Yolo Loam (YL) models with cement ratio of 0 to 2%. As a result, static failure tends to be distinct (thin localized shear band). From the observation of centrifuge tests, multiple slip surfaces may yield simultaneously during dynamic loading (hence more diffused shear band) whereas distinct slip surface may develop without limitation of time for static failure. Also, dynamic slip surface tends to reach deeper and less displacement than static slip surface. Kutter(1982)'s finding regarding static and dynamic deformation is also confirmed for weakly cemented sensitive clay (S_t up to 20). A brief description is provided regarding the degree of cementation, peak ground acceleration, and pore pressure ratio. Physical modeling using weakly cement treated clay slope is proved to be an effective tool to study sensitive slope stability.