Analysis of active earth pressure and rotational displacement at retaining wall under seismic loads

It is significant for the reliability assessment of retaining wall to analyze the displacement and earth pressure induced by earthquake. Based on the pseudo dynamic method, a new model is proposed to compute the active earth pressure. The proposed model considers time effects, phase difference of wave spread, overload friction on the back of retaining wall, cohesion and internal frictional angle of backfill soil. Then, the active earth pressure, distribution pattern and height of action point are obtained. Meanwhile, taking the seismic response of retaining wall, the rotational displacement about the toe of retaining wall is determined. Comparison between the Mononobe-Okabe method and present model is carried out. The results show that the active earth pressure obtained by present model is similar to the Mononobe-Okabe method. But the height of action point obtained by Mononobe-Okabe method is lower than present model; this revealed that seismic engineering design by using Mononobe-Okabe method may be led to risk. Finally, the dependence of the rotational displacement of retaining wall on the seismic coefficients, friction on the back of retaining wall, surcharge, time effect, cohesion and internal friction angle of backfill soil are discussed by case studies.