Application of geological strength index system for slope stability studies of the crocker formation in Kota Kinabalu, Sabah
The main objective of this study is to apply Geological Strength Index (GSI) classification system for slope stability study in Crocker Formation of Kota Kinabalu area. Six slopes were selected based on different type of composition and structure as in the GSI chart. The geological mapping and di...
Saved in:
| Main Author: | |
|---|---|
| Format: | Thesis |
| Language: | English |
| Published: |
2017
|
| Subjects: | |
| Online Access: | https://eprints.ums.edu.my/id/eprint/16860/1/Application%20of%20geological%20strength.pdf |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| id |
my-ums-ep.16860 |
|---|---|
| record_format |
uketd_dc |
| spelling |
my-ums-ep.168602017-11-20T02:16:06Z Application of geological strength index system for slope stability studies of the crocker formation in Kota Kinabalu, Sabah 2017 Lee, Kiun You QE Geology The main objective of this study is to apply Geological Strength Index (GSI) classification system for slope stability study in Crocker Formation of Kota Kinabalu area. Six slopes were selected based on different type of composition and structure as in the GSI chart. The geological mapping and discontinuity survey were conducted to obtain quantitative description of discontinuities as well as rock sampling based on rock unit and grain sizes. GSI ratings were analysed using three GSI approaches which are GSI₁₉₉₇, GSI₂₀₀₇ and GSI₂₀₁₃. The results show that GSI₂₀₀₇ was the most suitable GSI approach to be applied at the Crocker Formation. Parameters of disturbance factor (D), uniaxial compressive strength (UCS) and rock mass properties were obtained through field observation, laboratory work and correlation of Hoek-Brown criterion. Based on the results, it was found that, GSI rating has the greatest influence on rock mass properties followed by UCS and disturbance factor. These parameters were directly proportional to the rock mass properties. Intact rock constant however was inversely proportional to cohesion and tensile strength because of the present of shale and silt material. Numerical analyses of kinematic, finite element, (FEA) and limit equilibrium (LEA) analyses were performed to analyse the slope condition. Kinematic analysis showed that only slope S1 and slope S5 have probability for wedge failure. FEA and LEA results indicated that all slopes have the safety factor value that can be considered as stable, with FEA considered to be more suitable method since it can analyse both elastic and plastiC properties (elasto-plastic), additionally, it also capable of handling more complex failure plane and geometry. The safety factors obtained in FEA considered and computed based on rock mass properties which were neglected by LEA. Besides GSI rating, slope geometry also found to influence the slope condition, therefore, this parameter must be incorporated for slope stability analysis. Finally, the rock cut slope design was proposed with focus on mitigating localised failure and reducing water pressure build up behind the slope face. No obvious correlation can be made between GSI and rock cut slope design because it predominantly controlled by geometry, lithology and stability of individual slope rather than GSI rating. 2017 Thesis https://eprints.ums.edu.my/id/eprint/16860/ https://eprints.ums.edu.my/id/eprint/16860/1/Application%20of%20geological%20strength.pdf text en public other masters Universiti Malaysia Sabah Faculty of Science and Natural Resources |
| institution |
Universiti Malaysia Sabah |
| collection |
UMS Institutional Repository |
| language |
English |
| topic |
QE Geology |
| spellingShingle |
QE Geology Lee, Kiun You Application of geological strength index system for slope stability studies of the crocker formation in Kota Kinabalu, Sabah |
| description |
The main objective of this study is to apply Geological Strength Index (GSI)
classification system for slope stability study in Crocker Formation of Kota Kinabalu
area. Six slopes were selected based on different type of composition and structure
as in the GSI chart. The geological mapping and discontinuity survey were
conducted to obtain quantitative description of discontinuities as well as rock
sampling based on rock unit and grain sizes. GSI ratings were analysed using three
GSI approaches which are GSI₁₉₉₇, GSI₂₀₀₇ and GSI₂₀₁₃. The results show that GSI₂₀₀₇ was the most suitable GSI approach to be applied at the Crocker Formation.
Parameters of disturbance factor (D), uniaxial compressive strength (UCS) and rock
mass properties were obtained through field observation, laboratory work and
correlation of Hoek-Brown criterion. Based on the results, it was found that, GSI
rating has the greatest influence on rock mass properties followed by UCS and
disturbance factor. These parameters were directly proportional to the rock mass
properties. Intact rock constant however was inversely proportional to cohesion
and tensile strength because of the present of shale and silt material. Numerical
analyses of kinematic, finite element, (FEA) and limit equilibrium (LEA) analyses
were performed to analyse the slope condition. Kinematic analysis showed that only
slope S1 and slope S5 have probability for wedge failure. FEA and LEA results
indicated that all slopes have the safety factor value that can be considered as
stable, with FEA considered to be more suitable method since it can analyse both
elastic and plastiC properties (elasto-plastic), additionally, it also capable of
handling more complex failure plane and geometry. The safety factors obtained in
FEA considered and computed based on rock mass properties which were neglected
by LEA. Besides GSI rating, slope geometry also found to influence the slope
condition, therefore, this parameter must be incorporated for slope stability
analysis. Finally, the rock cut slope design was proposed with focus on mitigating
localised failure and reducing water pressure build up behind the slope face. No
obvious correlation can be made between GSI and rock cut slope design because it
predominantly controlled by geometry, lithology and stability of individual slope
rather than GSI rating. |
| format |
Thesis |
| qualification_name |
other |
| qualification_level |
Master's degree |
| author |
Lee, Kiun You |
| author_facet |
Lee, Kiun You |
| author_sort |
Lee, Kiun You |
| title |
Application of geological strength
index system for slope stability
studies of the crocker formation
in Kota Kinabalu, Sabah |
| title_short |
Application of geological strength
index system for slope stability
studies of the crocker formation
in Kota Kinabalu, Sabah |
| title_full |
Application of geological strength
index system for slope stability
studies of the crocker formation
in Kota Kinabalu, Sabah |
| title_fullStr |
Application of geological strength
index system for slope stability
studies of the crocker formation
in Kota Kinabalu, Sabah |
| title_full_unstemmed |
Application of geological strength
index system for slope stability
studies of the crocker formation
in Kota Kinabalu, Sabah |
| title_sort |
application of geological strength
index system for slope stability
studies of the crocker formation
in kota kinabalu, sabah |
| granting_institution |
Universiti Malaysia Sabah |
| granting_department |
Faculty of Science and Natural Resources |
| publishDate |
2017 |
| url |
https://eprints.ums.edu.my/id/eprint/16860/1/Application%20of%20geological%20strength.pdf |
| _version_ |
1747836446001070080 |