Rock Mechanics
Erfan Amini; Masoud Mojarab; Hossein Memarian
Abstract
Landslides are defined as the downward movement of a portion of land materials under the direct influence of gravity. Landslides would get triggered by a wide spectrum of initiative factors such as earthquakes as a site effect of that event. In the vicinity of Tehran, significant historical earthquakes ...
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Landslides are defined as the downward movement of a portion of land materials under the direct influence of gravity. Landslides would get triggered by a wide spectrum of initiative factors such as earthquakes as a site effect of that event. In the vicinity of Tehran, significant historical earthquakes have occurred; therefore, tracing them could enhance the Tehran’s historical earthquake catalogue, due to the reason Tehran is a metropolitan and capital of Iran. However, paleoseismology could not determine the magnitude and seismic characteristics of historical earthquakes. Mobarak Abad landslide is a large and historical landslide located on Haraz road, a vital artery connecting Tehran to the Mazandaran Province, and there are significant faults like Mosha, North Alborz, and Khazar in its neighborhood. Hence, it is probable that this landslide occurred due to the generation of dynamic force resulting from an earthquake. Therefore, in this study, the geometrical characteristics of the landslide were measured by field surveying. Then with the empirical equations proposed by various researchers, we estimated the landslide volume and the magnitude of the corresponding earthquake, respectively. In the following, the epicenter and hypocenter of all the historical earthquakes within 200 kilometers of the landslide were identified. Then we utilized some conditions such as Keefer's graphs, error value in epicenter location, and peak ground acceleration to omit earthquakes and identify the corresponding earthquake event. The results demonstrate that two earthquakes of 1830 AD and 855 AD with a maximum acceleration of 0.16g are more probable than the 743 AD earthquake.
Hassan Sarfaraz; Mohadeseh Sarlak; Fatemeh Ashoor; Erfan Amini
Abstract
In rock slopes, block toppling failure is a prevalent instability. In this instability, rock mass consists of a series of dominant parallel discontinuities that are dipping steeply into the slope face, and a series of cross-joints are located normal to the dominant discontinuities. Blocks may slide or ...
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In rock slopes, block toppling failure is a prevalent instability. In this instability, rock mass consists of a series of dominant parallel discontinuities that are dipping steeply into the slope face, and a series of cross-joints are located normal to the dominant discontinuities. Blocks may slide or rotate due to their weight along the natural cross-joints at their base, and the tensile strength does not significantly affect the stability of the rock slope. The rounding edge of rock columns is a special feature of spheroidal weathering. Firstly, a literature review of block toppling instability is presented. Next, applying the Sarma approach, a new theoretical analysis is proposed for the rock columns with rounded edges. One of the advantages of the proposed approach is that by determining the sign of a parameter called KC, the stability status can be specified. The suggested solution is compared with a pre-existing analytical method through examples and case study. Comparisons indicate that the proposed approach has a satisfactory agreement. It can be concluded that with weathering and rounding of the block edges, the safety factor decreases non-linearly. Therefore, this solution can be used to evaluate the blocky toppling failure regarding the erosion phenomenon.
