INSTABILITY AND STATIC LIQUEFACTION ANALYSIS OF LOOSE SANDS WITH A STATE-DEPENDENT CONSTITUTIVE MODEL
HUANG Maosong1，2，QU Xie1，2，LU Xilin1，2
(1. Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education，Tongji University，Shanghai 200092，China；2. Department of Geotechnical Engineering，Tongji University，Shanghai 200092，China)
Abstract：When the finite element method is used to simulate the instability of saturated sand，an elastoplastic constitutive model which can accurately reflect the plastic volumetric response of the sand is needed. An implicit algorithm of integration for the state-dependent sand model is derived. Two types of numerical errors occurred during the calculation process；and an appropriate numerical treatment is presented. Loose sand specimens under plane strain and undrained conditions are analyzed. The numerical results demonstrate differences of the static liquefaction phenomenon between rapid and slow loading cases. Another numerical example concerning the man-made slope of loose sand on seabed is analyzed with the negative work of second-order as the criterion of instability. The numerical results demonstrate the rationality of the criterion and reliability of the numerical algorithm.
2014, Vol. 33 
