ANALYTICAL AND NUMERICAL LIQUEFACTION ANALYSIS OF ADAPAZARI BOREHOLE AND SITE DATA

Different methods can be used to assess the liquefaction susceptibility of sites and soil layers. The governing parameters are material type, groundwater level, layer depth, stress ratio, density, fine content as well as the peak ground acceleration. A number of analytical approaches and a probabilistic study have been applied to borehole and site data from Adapazari, where especially the city center suffered from damage due to liquefaction after the 1999 Kocaeli earthquake (e.g. Buchheister et al. 2006). This was performed with good agreement of the different approaches concerning the identification of liquefied sites but moderate success matching the specific liquefied layers. Now a flow liquefaction surface model has been implied into a commercial numerical software tool and counterchecked with the liquefaction susceptibility of the analytical methods. The flow liquefaction line takes into account the development of the effective stresses in the p’-q plane towards a collapse point. The pore pressures are generated using equivalent cyclic shear stresses generated with an equivalent linear model. The calculations are performed on one dimensional soil columns with an accelerated bottom line. The capability of the analytical and the numerical methods will be pointed out and compared to the field data.