Urban noises and earthquakes effects on dynamic slope stability – a case study: Arash-Esfandiar tunnel

Abstract

Slope stability is one of the main concerns among geotechnical researchers. Many aspects have been studied to examine their effects on slope stability (e.g. soil and slope properties). Besides, the dynamic slope stability analysis has great importance due to the danger of destructive dynamic stresses such as earthquakes, storms. On the other hand, urban areas daily encounter numerous construction projects, which generate unlimited microseismic noises that are usually considered ineffective on the dynamic slope stability. In short-term periods of time, these noises are not able to make impacts on slope stability; however, the long-term effects of the noises have not been studied sufficiently. In this study, firstly, geological and geotechnical investigations were done to obtain the soil types, parameters and characterisations of an excavation located in Tehran. Then, using a microtremor, the noises of the area were recorded for 52 min. In addition, the seismogram records of six earthquakes which had occurred in Tehran were taken. These seven records (the noises and six earthquakes) were separately applied to the geotechnical model and the behaviour of the soil (caused displacements and changes in the factor of safety) was observed. Thereafter, the results were obtained and the effects of the noises were compared with the six earthquakes. Accordingly, the displacements of the noises were considerable in comparison with the earthquakes displacements and the noises would cause the collapse in the slope after about six years. The results confirmed the effectivity of the urban noises and showed the importance of urban noises.