Geologic Techniques in Civil Engineering 



1137 



PROBLEM 



METHOD 



RESULTS 



(lAI 



GEOLOGIC DATA 



(IB) 

 RESISTIVITY 



DC POWER-. .-AMPS (I) 



VOLTS ._^-(V) 

 ELECTRODES 



i-lXi-i-*^ 



RESISTIVITY: ZTTA ^ OHM. FT 



measure: RESISTIVITY OF EARTH 

 MATERIALS WITH INCREASING 



DEPTH BY EXPANDING "a" 



SPACING 



(IC) 

 RESISTIVITY DEPTH CURVES 



RESISTIVITY OHM FT 

 400 800 1200 



-i^ 



40' LAKE 

 BEOS 



*— '160' 

 DRILL 

 HOLE 



LAYER DEPTHS ARE 

 CALCULATED FROM CURVE 



MATERIALS - GRAVEL DEPOSITS 

 LOCAT'ON a EXTENT 



CLAY C3J° 

 GRAVEL 



(2BI 

 RESISTIVITY 



SEE ABOVE 



(ZC) 

 FIXED SPACING TRAVERSE 



KEEP "A" SPACING FIXED 

 TRAVERSE AREA i INVESTIGATE 

 TO FIXED DEPTH 



8001^^ 



200 

 0-1 



/ \ A. 20 FT 



LAY -^ -cr-rr7i_ WATER 



^t-^-2*^ TABLE 



'GRAVEL a SAND 



(FOR GEOLOGICAL 

 CONDITIONS SHOWN) 



13A) 

 BED ROCK DEPTH 



(38) 

 RESISTIVITY 



SEE ABOVE 



(3C) 

 CROSS- SECTIONS 



RESISTIVITY EXPANDING 

 ELECTRODE KEASUREI^ENTS 

 OF STATIONS AT SITE PLOT 

 RESISTIVITY DEPTH CURVES 



u. 

 20- 



k40 

 60 



•RESISTIVITY DEPTH POINTS; 

 FROM INTERPRETATION OF 

 RESISTIVITY CURVES. 



Figure 596. Resistivity methods applied to engineering geology. 



