Potential of Soil Liquefaction Assessment in Chalus and Nowshahr Region during an Earthquake using Shear Wave Velocity (Vs) Method

Liquefaction is one of the most common ground deformation effects of earthquakes often a major cause of damage and destruction to buildings and infrastructures. The area on the study (Chalus and Nowshahr region) is located on the coastal strip of Caspian Sea, on the loose alluvial material which has been hit by numerous earthquakes throughout history. In this study, the shear wave velocity (Vs) method has been used with five experimental relationships to evaluate the soil liquefaction potential of Chalus and Nowshahr region under the assumption of non-cementation and cementation conditions. Due to the distribution of boreholes evaluated in the sediment section of the area which is less than 10,000 years old, solutions with noncemented conditions are acceptable. Analyses have shown that among 46 borehole loops, 35 boreholes are prone to liquefaction, which most of them are located in the region of Nowshahr. Considering the values of the liquefaction potential index obtained, based on the shear wave velocity method, in non-cementation conditions, 8.7% of area is PL = 0, 15.2%, in the range of 5> PL> 0, 41.3% in the range of 15> PL> 5 and 34.8% in the range of 15< PL. Due to the fact that the surface depth is an important parameter in soil lubricity, and the high level of the station, considering the high potential of seismicity of the area as well, the likelihood of liquefaction increases.