Experiment on earthquake-induced permanent deformation of nanjing recently deposited muddy soil

Abstract

The analysis of earthquake-induced ground settlement is based on study of soil permanent strain under ground motion. So far, some experiential formulas have been established to estimate the permanent strain of soils. But the parameters of the established experiential formulas are too much and a lot of tests must be done to determine these parameters. A series of permanent deformation of Nanjing recently deposited muddy soil under cyclic load were completed by WFI cyclic triaxial apparatus and the soil permanent strain experiential formula with three parameters is given. The experimental results show that the permanent strain of Nanjing recently deposited muddy soil increased suddenly when permanent strain is over 4%. So, the permanent strain value 4% may be as the failure standard of soil element under cyclic load. The relationship of axial cyclic stress amplitude and cyclic number under different confining pressure and consolidation ratios in the system of double logarithm coordinates could be normalized by dynamic shear stress ratio based on the concept of maximum cyclic shear plane. So permanent strain parameters of Nanjing recently deposited muddy soil can be determined by test under one confining pressure and consolidation ratio. The soil permanent strain experiential formula with three parameters could predict the earthquake-induced ground settlement of Nanjing recently deposited muddy soil. For application purposes, the permanent strain parameters of Nanjing recently deposited muddy soil are given under cyclic load. © 2008 Science Press Beijing and Springer-Verlag GmbH Berlin Heidelberg Geotechnical Engineering for Disaster Mitigation and Rehabilitation.