Analysis Of the Mechanism of Soil : 1st Report. Cutting Patterns of Soils

Abstract

All equipments of earth-moving machines (e.g. bulldozer, power-shovel) cut soil. In order to analyze the mechanism of soil cutting, a study on cutting of soil is made. The main results are as follows: (1) Cutting patterns of soils consist of the following three types-shear type (sand or plastic bentonite), flow type (plastic loam) and tear type (compacted loam). (2) Failure conditions of soils are investigated. Shear type and flow type are brought about by shear failure, and tear type by tensile failure. The difference between shear type and flow type occurs only from apparent difference of shear-line. (3) Experiments to measure the distributions of internal stresses in soils are carried out. From these results, the correspondence between cutting patterns and failure conditions is explained. (4) Comparison between cutting patterns of soils and cutting patterns in other fields (e.g. metal cutting) is made.