A FIELD TEST FOR THE SPECIFIC CUTTING RESISTANCE

摘要

To predict the cutting resistance or dozing effect of running apparatus soil strength must be measured easily in-situ. As one of the tests the author proposed a field testing method to determine the specific cutting resistance, which has a closely linear relationship to the cutting resistance of sandy soil. The testing procedure is very simple, i.e. digging out the ground by rotating steel plate penetrated into the ground around a fixed point at the ground surface, its maximum digging moment is measured and dividing the moment by width of the plate and by the cube of penetrating depth of the plate, this value we defined the specific cutting resistance The experimentally obtained values of the specific cutting resistance were found to be independent of the depth if the sandy soil was uniform, and these had close relationship to relative density of sands. From this character we can use the parameter (specific cutting resistance) as an independent variable which represents the property of sandy aoil for dimensional analysis. As an example, cutting submerged sand, it has a distinctive feature i.e. cutting resistance increases distingishly with increasing cutting speed, is explained.