An evaluation of suction in Hong Kong residual soils by back analysis of existing slopes | |
| Author | Chang, Chung-hung David |
| Call Number | AIT Thesis no.GT-78-08 |
| Subject(s) | Slopes (Soil mechanics) Shear strength of soils |
| 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 literature on suction, infiltration and slope stability analysis pertinent to the treatment of the present slope stability problems in Hong Kong is reviewed. Twenty-four slopes distributed over nine different areas of Hong Kong and comprising three different soil types (decomposed volcanics, .decomposed granite, ·decomposed volcanic colluvium) have been back-analyzed by Janbu's routine method and the suction required to give a factor of safety of unity evaluated. The suction was assumed to act entirely as negative pore pressure uniformly distributed over the part of the slip surface above the phreatic line. The suction values found were very low, even under the assumption of a rainstorm intensity of 1 in 1000 years, and never exceeded 60 kPa. Comparison among different slopes also indicates that the required suction increases with the angle of the slope. In addition, a sensitivity analysis involving the parameters used in Janbu's method was carried out for fifteen slopes. As expected, the cohesion and friction angle and the pore pressures acting on the submerged portion of the slip surface are the dominant factors determining stability, while variations in bulk density have little influence on the factor of safety. No. reliable in-situ suction measurements are yet available for Hong Kong soils but past and present efforts in suction research are reviewed and recommendations made for future steps to be taken. |
| Year | 1979 |
| 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. |
| Examination Committee(s) | Campbell, K.V. ;Balasubramaniam, A.S. |
| Scholarship Donor(s) | The Keidanren Foundation, Japan |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1979 |