| Author | Tam, Heng-kong |
| Call Number | AIT Thesis no.GT- 80-12 |
| Subject(s) | Strains and stresses
|
| Note | A thesis submitted in partial fulfilment of the requirements for the degree of Master of Engineering, School of Engineering and Technology |
| Publisher | Asian Institute of Technology |
| Abstract | The conventional triaxial testing procedures adopted in current
practice in Hong Kong were investigated. The role played by suction in unsaturated compacted specimens with respect to strength and volume
change was also studied . The material chosen in this investigation was a Grade VI volcanic soil taken from the Tai Po area in Hong Kong, and test specimens were compacted at pre-determined densities and water contents. The experimental programme consisted of four different types of testing procedures, two of which were carried out in back-saturated specimens and two on unsaturated specimens. The test procedures on saturated specimens comprised: (1) Two series of dead load tests in which the pore water pressure was increased until failure conditions were reached thus simulating a possible field stress
path. (2) Three series of conventional strain-controlled consolidated drained triaxial compression tests in accordance with present practice .
The strength parameters obtained are discussed and applied to slope stability analysis. Comparisons between test results from these two different testing procedures suggest that conventional testing procedures may underestimate the shear strength parameters for swelling soils. The test procedures on unsaturated specimens included: (1) ยท Three series of dead load tests simulating approximately a stress path which would be followed by an element of soil in a rain-induced slope failure.
The role of suction with respect to strength and the volume change behavior during "wetting-up" was analyzed, since the mode of .failure, i.e.
whether dilatant or compressive, is regarded as a criterion for fill slope design. The effect of partial saturation on the strength was also expressed
in terms of Bishop's X parameter and also by Fredlund' s stress state variables, Both Bishop's and Fredlund' s approach yielded numerically '.'similar
strength equations. The effect of suction on slope stability is also
discussed. (2) Three series of isotropic compression tests at preconditioned initial suctions of different values in order to establish the stress state variables vs. volume-weight relationships. |
| Year | 1981 |
| Type | Thesis |
| School | School of Engineering and Technology |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Geotechnical and Transportation Engineering (GT) |
| Chairperson(s) | Brenner, R.P. ; Brand, E.W.
|
| Examination Committee(s) | Prinya Nutalaya ; Ohta, Hideki |
| Scholarship Donor(s) | Federation of Economic
Organization, Japan
|
| Degree | Thesis (M. Eng.) - Asian Institute of Technology, 1981 |