بررسي آيين نامه اتحاديه اروپا(Eurocode 8) در ارزيابي پتانسيل روانگرايي خاكها در جنوب شرق تهران

Precise Evaluation of Eurocode 8 in Soils Liquefaction Potential at the Southeast of Tehran

Liquefaction is defmed as the transformation of granular materials from solid to liquefied states as the result of increased pore water pressure and reduced effective stress. Pore water pressure is increased due to the tendency of granular materials to be compacted when they are subjected to cyclic shear deformation. The state change occurs most readily in loose to moderate dense granular soils with poor drainage, such as silts, sands and gravels capped by or containing seams of impermeable sediment. Evaluating soil liquefaction resistance is an important part in seismic design of foundation engineering and microzonation. Several in situ and laboratory methods for defining soil liquefaction potential are proposed. In this study, two prediction methods, suggested by NCEER-1997 and Eurocode 8-1998, are compared based on SPT results in three boreholes at southeast of Tehran. According to the results obtained in this study, NCEER method is more conservative in assessment of soils liquefaction potential in comparison to Eurocode 8.