Effect of roots on the undrained shear strength of a colluvial soil | |
| Author | Ng, Sai Ming James |
| Call Number | AIT Thesis no. 770 |
| Subject(s) | Soils Shear strength of soils Plant-soil relationships |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering at the Asian Institute of Technology, Bangkok, Thailand . |
| Publisher | Asian Institute of Technology |
| Abstract | The effects of mechanical reinforcement of plant roots and their influence on the shear strength of soils were investigated. Special reference to an application to slope stability is made. Corn plants were grown in a colluvial soil obtained from Kabinburi, Thailand. Soil samples with and without roots were tested in a specially designed direct shear box (30 cm x 15 cm area and 30 cm deep). The shear strengths obtained from samples containing live corn roots of two different lengths, and from samples containing dead roots are compared with the strength of the soil without roots. The samples containing roots were prepared in two different manners; viz. some were grown in individual sample boxes, while others were cut from a corn bed in a big tank. Results of the experiments indicate that the corn roots enhance the shear strength of the soil. An increase of as much as 80% has been observed, but the average increase was about 44%. The presence of the roots increases the cohesive intercept of the total stress envelope but not the angle of shearing resistance, i.e., the envelope is shifted parallelly upward. Furthermore it was found that the roots also changed the stress-strain characteristics of the soil, and compacted the soil to a higher density. The contribution of the roots to the increase in shear strength diminished rapidly, however, after the plants were cut. |
| Year | 1975 |
| Type | Thesis |
| School | Student Research Before 1980 |
| Department | Other Field of Studies (No Department) |
| Academic Program/FoS | Thesis (Year <=1979) |
| Chairperson(s) | Brenner, R.P |
| Examination Committee(s) | Brand, E.W. ; Kazi, A. |
| Scholarship Donor(s) | Keidanren of Japan |
| Degree | Thesis (M. Eng.) - Asian Institute of Technology, 1975 |