RELATIONSHIP BETWEEN GEOPHYSICAL AND GEOTECHNICAL PROPERTIES OF MARINE-SEDIMENTS USING BIOT-STOLL MODEL

The objective of the present investigation is to develop possible rela tionships between geophysical and geotechnical properties of marine se diments from the east (Madras) and the west (Cochin) coasts of India b y experimental and theoretical methods. Among different types of geoph ysical properties of the sediment, acoustical and electrical propertie s were measured in the experiment To correlate the acoustical electric al and the geotechnical properties, experiments were conducted with th e help of a modified consolidometer. The permeability was predicted fr om the Biot-Stoll model with the use of geophysical and geotechnical p arameters. The permeability predicted from the Biot-Stoll model was co mpared with the measured values (both direct method and indirect metho d from consolidation testing). Permeability pre dicted from the Biot-S toll model agrees reasonably well with the measured values for both cl ays tested. The Biot-Stoll model underestimates the coefficient of per meability by 40% at a porosity of 0.6659, this reduces to about 3% at a porosity of 0.5506 for Cochin clay. Considering that the permeabilit y of clays varies in the order of 10(-7) to 10(-9) cm/s, even 40% vari ation will appear relaziuely small for permeability The results also s how that correlations can be attempted between acoustical (i.e., compr essional wave velocity), electrical (formation factor), and various ge otechnical properties.