Analysis of Soil Liquefaction Potential through Three Field Tests-Based Methods: A Case Study of Babol City

Abstract

Landslide and particularly liquefaction have been responsible for extensive damages to infrastructures and residential lands in recent earthquakes around the world [1]-[4]. Liquefaction phenomenon is associated with the development of large pore-water pressures in soils due to cyclic loading effects of earthquakes. Consequently, effective stress reduces and soil loses its strength. The investigation of failure of soil masses during earthquakes requires sciences of geology and engineering [5], [6]. To confront destructive effects of liquefaction, the assessment of soil liquefaction potential and recognition of liquefiable regions are essential. There are several laboratory tests for evaluation of soil liquefaction potential such as cyclic triaxial and cyclic torsional shear tests. Since extracting high quality undisturbed specimens is relatively expensive and the simulation of actual field conditions in laboratory is difficult, approaches based on in-situ tests such as shear wave velocity (Vs) test, Cone Penetration Test (CPT) and Standard Penetration Test (SPT) are widely accepted for estimation of soil liquefaction. The SPT, due to its simplicity of execution, is one of the most popular in-situ testing techniques used to achieve idea about the stratigraphic profile at a site [7]-[9]. SPT-based approaches have been accepted for evaluation of soil liquefaction and Standard Penetration resistance has been utilized as an index of soil liquefaction resistance during Abstract: During earthquakes, ground failure is commonly caused by liquefaction. Thus, assessment of soil liquefaction potential in earthquake-prone regions is a crucial step towards reducing earthquake hazard. Since Babol city in Iran country is located in a high seismic area, estimation of soil liquefaction potential is of great importance in this city. For this purpose, in the present research, using field-based methods and geotechnical data (such as unit weight of soil, relative density, SPT number, shear wave velocity and cone tip resistance) of 60 available boreholes in Babol, three liquefaction maps were provided. Finally, one comprehensive liquefaction map was presented for soil of Babol city. The obtained results in this paper are well in line with the previous investigations. Based on the results, the factor of safety in 45% of the study area is less than one (liquefaction occurrence). In addition, the results indicate that since each field-based method requires particular data, applying various field tests is necessary for a more accurate liquefaction assessment.