Prediction of Seismic Active Earth Pressure Using Curved Failure Surface with Localized Strain

Abstract

Problem statement: Correct evaluation of the earth pressure against retaining structure during earthquake is essential for the safe and economic design of geotechnical structures. Progressive deformation in the backfill and the assumed shape of failure wedge affect the calculated values of seismic earth pressures. However, no research until now is available that considers both of these two factors in an analysis. Approach: In this study, a new analytical methodology was proposed that took into the account the progressive failure of the backfill soil as well as the shape of the failure wedge. A new formulation was first established taking the failure plane as the combination of a curved lower part and a straight upper part. The localized deformation of the backfill was accounted for in the formulation by utilizing the mobilized friction angle and the peak friction angle depending on the locations along the failure surface. The proposed methodology was validated by comparing the calculated results with the established experimental results. Calculations were also performed for different types of wall with various backfill inclinations. Results: The developed methodology could predict the seismic active earth pressure against retaining structure with reasonable accuracy. It could also realistically predict the active failure domain in the backfill soil at the high excitation level, as compared to the pseudo-static solution provided by the well-known Mononobe-Okabe method. Conclusion/Recommendations: It was observed that the Mononobe-Okabe method underestimates the seismic active earth pressure and overestimates the domain of failure zone in the backfill, especially under intense seismic excitation. The proposed methodology, therefore, can contribute greatly towards the economic earthquake resistant design of geotechnical structures.

Pseudo-static limit analysis by discontinuity layout optimization: Application to seismic analysis of retaining walls

“…In this context, a modification of the Mononobe-Okabe method and alternative simplified pseudo-static approaches have been recently proposed allowing for a progressive failure in the backfills ([8]; [9]). The single most significant shortcoming of the simplified pseudo-static approach arises from the assumption that dynamic loads can be idealized as static actions.…”

Effects of reinforcement on the geo-structure for mitigation of the earthquake effects

“…Pseudo static method, Pseudo dynamic method, Horizontal slice method, etc.). In Pseudo static method (Bathurst and Cai, 1995;hazarika 2009;Greco, 2014), earthquake force is considered as equivalent static forces using horizontal and vertical acceleration coefficients. Mononobe and Matsuo (1929) and Okabe (1924) developed limit equilibrium approach by using Coulomb's earth pressure theory.…”

A New Viewpoint for Seismotectonic Zoning

“…In order to get access to distribution mode of seismic deformation various seismotectonic studies have been conducted (Unesco, 1985;Berberian, 1976;Nowroozi, 1976;1979;Nowroozi and Ahmadi, 1986;Mirzaei et al, 1999;Tavakoli and Ghafory-Ashtiani, 1999;Ansari et al, 2009. However the seismic studies are important in various scales (Benmenni and Benrachedi, 2010;Amiri and Tabatabaei, 2008;Al-Zoubi, 2005;Chakraborty and Choudhury, 2009;Hazarika, 2009;Choopool and Boonyapinyo, 2011;Abu-Lebdeh et al, 2011;Teachavorasinskun et al, 2009;Escobar et al, 2008;Mayoral and Romo, 2008;Musmar, 2007;Singh and Roy, 2009), but the seismotectonic zoning are mainly conducted in largescale without any effort on small-scale basis because of problems and disputes. It is possible to clarify the basis of ambiguities and disputes concerning on zonings through bringing up a basic problem and also considering subjectivity with regard to method and quality of zonings.…”