Soil liquefaction is one of the major causes of damage due to earthquakes. Specifically in Chile, evidence of liquefaction has been observed on several sites along the country after the 2010 Mw 8.8 Maule earthquake. An ongoing research project involving the evaluation of liquefaction potential of different sites in the city of Concepción, has produced an extensive in-situ testing database. To contribute in the evaluation of liquefaction potential, a laboratory testing program is being performed through cyclic triaxial tests. The specimens tested consist of natural soils extracted at different sites from the city of Concepción. One of the objectives of this study is to evaluate the effects of non-inform cyclic loading on the threshold shear strain of natural soils. The results are compared with conventional methods to obtain the values of the cyclic shear strain amplitude. The evaluation of the dynamic properties of natural soil deposits potentially liquefiable are compared.