Analysis of the existing correlations of effective friction angle for eastern piedmont soils of Bogota from in situ tests

Abstract

To estimate the effective friction angle of soil from in situ test is a complicated job, due to high rates of strain existing in this kind of tests, which tend to be too invasive and disturb the vicinities of test depth, even the sample that eventually is taken at the site. Likewise, the most of the correlations found in the current bibliography to obtain the effective friction angle using field tests, have been developed for soils from different regions. For that reason when are implemented on tropical soils present high scatter, to compare the field parameter values with real results obtained at the lab. This research aims to use in situ tests define through of analysis of different correlations, which fits adequately to the specific conditions of the piedmont soils of Bogota. For the present study will be utilized data from SPT (widely used in Colombia) and SPT-T (never before conducted in the country), carried out considering the appropriated norms to each test, taking in account to SPT-T, doesn’t exist local standard governing such tests. The correlations for field procedures of the tests implemented were for effective confining and energy transference of the SPT hammer, since the state-of-the-art mentions it as the most affect the reliability of the final results. The final results show the tendency of the methodologies used to obtain the correlation, in relation with the real value of effective friction angle from of lab tests.