Performance-based analysis of cantilever retaining walls subjected to near-fault ground shakings

摘要

Considering the devastating damages of 'forward-directivity' on structures, a series of finite element models were conducted to evaluate the seismic performance of cantilever retaining walls under near-fault excitations. The wavelet approach was used to extract the velocity pulse of near-source motions, and a semi-artificial records reagent far-field earthquake was produced. Both were then imposed on the model, separately. The results indicated a vivid difference in lateral displacement, in which some cases up to differences of experienced 85% and forces along the walls were approximately equal. In view of this finding, a wide range of PGAs was applied to the near-fault scenarios of the models. The captured movements were compared with the recommended criteria for performance-based aseismic design of retaining structures. According to the numerical analysis, in most earthquakes, for accelerations exceeding 0.4 g, lateral displacement of the wall had a higher value than the permissible proposed limits. Also, accelerations exceeding 0.6 g for both near and far-field records resulted in wall failure (5% H). The final section of this research presents a comprehensive parametric study on the effects of ground motion characteristics and soil mechanical properties on system performance.