| Author | Lhamo, Rinchen |
| Call Number | AIT Thesis no.GE-18-07 |
| Note | A thesis submitted in partial fulfillment of the requirements for the
degree of Master of Engineering in
Geotechnical and Earth Resource Engineering, School of Engineering and Technology |
| Publisher | Asian Institute of Technology |
| Abstract | The stability of the slope is a greater concern to engineers and geoscientists as the socioeconomic consequences of the failures are huge. Evaluation of slope instability of right bank of Punatshangchhu Hydroelectric Project Authority (PHPA-I) dam, Bhutan has been carried out. The main geology of dam site is characterized by coarse-grained quartzo-feldspathic and biotite-muscovite gneiss. Since the start of the project in 2008, project encountered several geotechnical problems. During excavation at dam pit area, the shear zone got daylighted which triggered a huge movement of right bank of dam in 2013. Project has carried out various stabilization measures in arresting movement of right abutment of dam. Kinematic analysis was carried out in order to check mode and direction of movement. Further, boring log data were used to construct subsurface profile. Cross-section along the dam axis exhibits two prominent shear zones dipping towards valley with dip angle less than face slope. Upper daylighted shear zone was used for back analysis based on limit equilibrium (Janbu simplified) with non-circular block search method. Friction angle of 17.5o was obtained when (c = 0) during the movement. With the calibrated model, effectiveness of the stabilization measures like grouting, RCC pile & cable anchor were assessed. The safety factor of 1.138 was obtained with stabilization measures which was unsafe during the rapid drawdown with seismic loading. Therefore, remedial measures to remove overburden above El.1260 m was proposed. |
| Year | 2019 |
| Type | Thesis |
| School | School of Engineering and Technology (SET) |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Geotechnical Engineering (GE) |
| Chairperson(s) | Chao, Kuo Chieh; |
| Examination Committee(s) | Noppadol Phien-wejPham Huy Giao; |
| Scholarship Donor(s) | Thailand International Corporation Agency (TICA); |
| Degree | Thesis (M. Eng.) - Asian Institute of Technology, 2019 |