The Newmark sliding method was proposed by Newmark, which considers that the slide will begin to slip when the seismic acceleration exceeds the critical acceleration, and the final displacement of the slide can be obtained by double integral over the time of the difference between the seismic acceleration and the critical acceleration, which is called permanent displacement. In this aspect, the seismic slope stability analysis and evaluation method is a piece of basic work. Meanwhile, other studies focused on hazard assessment in the areas for the site selection of major projects and resettlement of migrants in mountainous areas where no major earthquakes happened so far but are with potential seismic risk in the future. Many researchers have studied the distribution of these earthquake-induced landslides. For example, the 2008 Wenchuan, China, M 7.9 earthquake triggered more than 56,000 landslides, killing about 20,000 people accounting for one-fourth of the total deaths. In recent years, dozens of large earthquakes with magnitude greater than M 7.0 have occurred worldwide, which directly caused huge losses of lives and property, and induced secondary effects such as tsunamis and landslides, greatly aggravating the degree of disasters. The improved method for calculating seismic slope permanent displacement presented in this paper solves the problem that the calculated value from the Newmark sliding method is smaller than the real value and is a useful improvement. Example calculations indicate that this approach permits to show the dropping cohesion and the dynamic critical acceleration of the slide block during the earthquake time history.
In this paper, this problem is analyzed, and a new method for calculating permanent displacement of seismic slope considering dynamic critical acceleration is proposed, in which the Monte Carlo simulation is used. The traditional Newmark sliding method assumes that the critical acceleration is constant but does not consider the inhomogeneity and dynamic reduction process of shear strength on the sliding surface, presumably leading to underestimation of the permanent displacement.
Newmark permanent displacement is an important index for evaluating seismic slope stability, which has been widely used in recent years.
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