Combined logging/penetration methods

A method is described for studying important soil and rock properties by simultaneous penetration and logging measurements. In penetration measurements, a BORROS Co. probe with a coned tip, 35.6 mm in diameter, a point angle of 60 deg, and with a friction roller 150 cm2 in area was dipped in the soil at a constant speed. Tip resistance and skin friction were measured. At the same time, gamma logging was carried out to determine natural radioactivity, gamma-gamma logging to determine bulk density, neutron-neutron logging to determine bulk density and porosity, and inclinometry. An original probe fitted with a NaI(Tl) scintillation detector with a crystal 25 mm in diameter and 100 mm in length was developed for gamma logging. For gamma-gamma logging, a 137Cs emitter probe was used with the emitter/detector distance of 45 cm. A NaI(Tl) crystal 18 mm in diameter and 50 mm in length was used for radiation detection. For neutron-neutron logging, a NIV 2 probe was purchased in the USSR and modified for simultaneous penetration measurements. A Soviet-made UMI 30 inclinometer with a modified case was used for inclinometry. (Ha)