Soil-tool interactions for tools of simple shape in dry sand | |
| Author | Sharma, Vinod Kumar |
| Call Number | AIT Diss. no.AE-90-1 |
| Subject(s) | Trafficability Tillage--Research |
| Note | A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Engineering, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Series Statement | Dissertation ; no. AE-90-01 |
| Abstract | Soil failure patterns caused by tools of simple shape have been recorded in dry sand under quasi-static conditions and correlated with the corresponding soil reactions which were simultaneously recorded. The soil failure was by progressive shear in all the experiments. Average shear angle was 26° ( - n/4- c/2) for all the rake angles (15°-140°) at an aspect ratio of 4. For a rake angle of 90°, it was 26° when aspect ratio was 3- 5 but was slightly higher for aspect ratios of two (28°) and one (29°). No distinct zones of soil, as described by the passive earth pressure theory, were observed. The observed soil failure patterns for tool width/depth ratio of 4 at different rake angles were grouped under three ranges. For rake angles from 15° to (90°-c), inclined shear surface emerged from the tool tip. In the second range of rake angles from (90°-c) to 90°, shearing of the block of soil started horizontally from the tool tip and progressed towards the top soil surface. Horizontal portion of the shear surface increased with increase in rake angle. The presence of a shearing surface within the soil failure zone at an angle of (90°-c) with the horizontal soil surface was indicated. In the third range of rake angles ( > 90°), stationary soil wedge was formed adjacent to the tool face. The soil failure patterns for tools of aspect ratio of two and one showed shear failure lines within the already failed zones, in addition to the failures occurring in the virgin soil. These soil failures, in two different zones, were not simultaneous. |
| Year | 1990 |
| Corresponding Series Added Entry | Asian Institute of Technology. Dissertation ; no. AE-90-01 |
| Type | Dissertation |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Food, Agriculture and Natural Resources (Former title: Department of Food Agriculture, and BioResources (DFAB)) |
| Academic Program/FoS | Agricultural and Food Engineering (AE) |
| Chairperson(s) | Singh, Gajendra;Gee-Clough, D.; |
| Examination Committee(s) | Gupta, C.P.;Balasubramaniam, A.S.; |
| Scholarship Donor(s) | Japanese Government; |
| Degree | Thesis (Ph.D.) - Asian Institute of Technology. 1990 |