Strength and consolidation behavior of remolded redbed claystone from Mae Moh Lignite Mine | |
| Author | Dongol, Abhishek |
| Call Number | AIT Thesis no.GE-23-10 |
| Subject(s) | Lignite industry--Waste disposal--Thailand Coal mine waste--Thailand Mine safety |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Geotechnical and Earth Resources Engineering |
| Publisher | Asian Institute of Technology |
| Abstract | The objective of this study was to evaluate the strength and consolidation behavior of remolded Redbed claystone within a critical state framework. This study was conducted following two slope failures that occurred in the northwestern waste rock pile at the Mae Moh Lignite mine in Thailand. A hypothesis of the failure was the slaking of the claystone at the base of the piles resulted in substantial strength loss relative to the intact blocky mass of the as-placed claystone waste rock. Consolidated undrained (CU) triaxial compression tests were conducted on 38-mm-diameter samples of remolded and intact specimens of the claystone. Remolded specimens were prepared from slurry and consolidated to form normally consolidated clay specimens. One dimensional consolidations test were conducted on remolded and intact claystone specimens prepared in a similar manner. The remolded specimens exhibited contractive, strain softening behavior in undrained shear typical of normally consolidated clays with effective friction angles ranging between 20°-21° (M = 0.8). The intact claystoneexhibited stiff, dilative behavior in undrained compression with higher strength parameters (M = 1.11-1.66). One dimensional consolidation tests on remolded specimens yielded only virgin compression, whereas similar tests on in-tact specimens yielded negligible recompression. The claystone transitioned from a strong, stiff, and dilative material to a soft, contractive soil with a drastic reduction in strength and an increase in compressibility. A modified Cam Clay model was parameterized via the triaxial and consolidation behavior to model the shear behavior of remolded Redbed claystone. The model predictions showed good agreement with observed laboratory test data, which supports the use of the model to in advanced stress-deformation modeling of the waste rock piles at Mae Moh Lignite Mine. |
| Year | 2024 |
| Type | Thesis |
| School | School of Engineering and Technology |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Geotechnical and Earth Resources Engineering (GTE)/Former name = Geotechnical Engineering (GE) |
| Chairperson(s) | Chao, Kuo Chieh;Bareither, Christopher (Co-Chairperson) |
| Examination Committee(s) | Avirut Puttiwongrak;Scalia, Joseph |
| Scholarship Donor(s) | AIT Scholarships |
| Degree | Thesis (M. Eng.) - Asian Institute of Technology, 2024 |