Produção Nacional
Revisado por pares
Correlation of Electrical Resistivity and Induced Polarization Data with Geotechnical Survey Standard Penetration Test Measurements
1999; Volume: 4; Issue: 2 Linguagem: Inglês
10.4133/jeeg4.2.123
ISSN1943-2658
AutoresAntonio C. O. Braga, Walter Malagutti F°, João Carlos Dourado, Chang Hung Kiang,
Tópico(s)Geotechnical and construction materials studies
ResumoResistivity (DC) and time domain induced polarization (IP) soundings were made in the Rio Claro and Corumbataí Formations within the Sedimentary Basin of Paraná in the state of São Paulo, Brazil. The Rio Claro Formation is composed of sand‐clay sediments and sandstones. The Corumbataí Formation consists of claystones, sandy siltstones and clay siltstones. The present paper shows a geoelectrical identification of the lithology and an estimate the relationship between the geoelectrical parameters (resistivity and chargeability from IP) and Dar Zarrouk parameters (transverse resistance T and longitudinal conductance S) with the geotechnical survey results using the Standard Penetration Test (SPT). Resistivity and chargeability values for the soils (layer above the water table) of the Rio Claro and Corumbataí Formations varied considerably, 131 to 26,646 ohm⋅m and 0.4 to 23.4 mV/V respectively, which is characteristic for unsaturated sediments. The contrast in chargeability between sandstones (Rio Claro Formation) and sandy siltstones (Corumbataí Formation) was small (0.1 to 5.8 mV/V). Fortunately, the contrast in resistivity identified these lithology (200 to 516 ohm⋅m and 37 to 40 ohm⋅m respectively). Clay siltstones and claystones (Corumbataí Formation) had resistivity and chargeability values that decreased in value as the amount of clay increased (35 to 12 ohm⋅m and 45.0 to 1.5 mV/V) because pure clays are characterized by low resistivities and low polarizabilities while clay siltstones layers have high polarizabilities and intermediate resistivities. The relation of geoelectrical parameters (resistivity and chargeability) and Dar Zarrouk parameters (T and S) to the SPT (blow counts) was variable chargeability and T data did not correlate satisfactorily. Resistivity and S data did correlate better resulting in empirical equations that relate these parameters to blow counts.
Referência(s)