Soil Liquefaction Seismic Risk Analysis Based on Post 1979 Earthquake Observations in Montenegro

The scale and consequences of soil liquefaction during April 15, 1979 Montenegro earthquake rose a problem of explanation of this phenomena and assessment of the ground behaviour during future earthquakes. The analysis, the details and results presented in this paper is divided into two parts: The first part comprises soil liquefaction during Aprill5 1979 earthquake including the analysis of both geotechnical conditions and excitation potential inducing them. In order to realise the scale and the properties of the phenomenon, distribution of the locations with manifestations likely to have been induced by soil liquefaction, as observed on the ground surface and on civil engineering structures, has been given and described. To identify the presence of conditions inducing soil liquefaction the geotechnical soil properties for several typical locations have been analysed. Analysis of the characteristic ground surface horizontal acceleration records obtained by the earthquake from the aspect of their potential to cause liquefaction have been also carried out. To determine the liquefaction potential of the considered earthquake detailed analysis of typical geotechnical model of a site have been performed. In the second part is presented the seismic risk analysis background for soil liquefaction aimed at explanation of the essential problems concerning the evaluation of geotechnical media comprising of loose sand under the effect of future earthquakes. At the same time, the complexity of the problems which have to be dealt with during the seismic risk investigations has been pointed out concerning the necessity of investigation in this sense. It is necessary to make some assumptions and simplifications for solving sane of these problems. Applying the results of the analysis from the first part as well as the assumptions and simplifications, an assesment of the seismic risk for soil liquefaction analysed in details in the first part applying one of the possible methodologies, has been carried out