Asimplified dynamic cone penetrometer is a useful apparatus for the measurement of the hardness of slope materials at many points and depths of the soil layer on steep mountains. Therefore, some physical and mechanical properties of soils, such as the unit weight and the shear strength parameter whose measurement generally needs much time and effort, were estimated by the simplified dynamic cone penetrometer hardness(
Nc)in many previous works. However, the estimated values often change depending on grains size reflecting lithology. In the present study, based on the results of field measurement of physical and mechanical properties of hillslope materials in six granitic mountains, we deduced the dry unit weight of gnus(γ
d, gf/cm
3)and the angle of internal friction(φ
sat, degree), the cohesion(
Csat, gf/cm
2)and the hydraulic conductivity(
K, cm/sec)of grus under saturated water content from two parameters of
Nc-value and grain size of soil as following regression equations:
γ
d=1.228
Nc0.135CC2.00.102φ
sat=1.377
NcCC0.5+26.61
Csat=4.049
Nc-46.70
CC0.0625+71.13
log
10K=-0.616log
10NcCC2.0-0.115-1.872
CC2.0-0.115where
CCD is the content for coarser grains than D mm. The values of
CC0.0625,
CC0.5 and
CC2.0 can be easily measured by sieving method, so that these parameters can be easily estimated using the above equations.
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