分割型ランマーを用いた簡易貫入試験機の分解能の向上 Improvement of resistance value in simple penetration tests using a variable impact weight
This paper proposes a new type of impact weight for simple penetration tests that is variable from 1- to 5-kgf in 1-kgf increments. Many simple penetration tests were conducted to estimate the effect of this weight in three actual forests. Experimental results provide a detailed description of the vertical distribution of penetration resistance values within the surface soil layer by using 2- and 3-kgf weights, which are lighter than conventional ones, i.e., 5-kgf. The ratio of penetration resistance values by using impact weights 5-kgf, 3-kgf, and 2-kgf, i.e., N<sub><i>5kgf</i></sub> : N<sub><i>3kgf</i></sub> : N<sub><i>2kgf</i></sub>, is nearly equal to 1.00:2.02:3.66. In addition, N<sub><i>3kgf</i></sub> nearly equals the resistance value obtained with Hasegawa's soil penetration test. These results show that variable impact weight is very useful for accurately estimating the physical characteristics of soil within forest slope where hillside collapse is liable to occur.
- 砂防学会誌 : 新砂防 = Journal of the Japan Society of Erosion Control Engineering
砂防学会誌 : 新砂防 = Journal of the Japan Society of Erosion Control Engineering 60(5), 47-53, 2008-01-15