Experimental Investigation of Three-dimensional Densely Packed Sand Cutting Processes

摘要

2D and 3D models of the process of cutting saturated soil with an infinitely wide blade that is at an inclined angle to the cutting direction have been developed and used in the dredging industry. However, in practice, the width of the cutting blade used is limited. In order to obtain more insight into the three-dimensional process of cutting saturated soil, laboratory experiments on soil cutting were made. This paper relates to the preparation of the densely packed and 'reproducible' sand in the laboratory and the determination of the relationship between the porosity obtained from density tests and the in situ penetration force. This force can be obtained by using cone penetration tests to determine the porosity of the soil in situ. The paper gives results of measurements of the pore water pressures on the surface of the cutting blade and their distribution in the longitudinal and transverse directions and also includes graphs showing the pore water pressure during the cutting process. For a blade of limited width, the experimental results showed that in the longitudinal direction the excess pore water pressure on the surface increases nearly linearly from the top of the blade, reaching its maximum value at the about 4/5 of the length of the blade and then decreases. In the transverse direction the excess pore water pressure on the surface of the blade is systemically distributed; the maximum value is at the centre of the blade and this value decreases from the centre to the side of the blade.