碩士 / 國立臺灣師範大學 / 地球科學系 / 103 / In-situ stress is an essential information for geological science and geotechnical engineering and plays an important role for the design of underground structures, natural resource exploration and underground storage of waste. In-situ stress is long-term interaction result among geological processes and the gravitational field. Although many factors can affect in-situ stress, so far the origin(s) of in-situ stress is not theoretically established yet. The measurement of in-situ stress can be a practically good solution.
Taiwan is an orogenic belt of oblique collision between the Eurasian Plate and the Philippine Sea Plate, known as a mobile tectonic region. Heping of Hualien is located in the northeastern part of the Backbone Range, where the reversal of the Philippine Sea Plate subduction polarity take place and structural history is complex. The Chang-Hua Coastal Industrial Park is a part of land reclamation area in the western Taiwan. Underground formations from shallow to deep similar to that of the Western Foothills are consisted of the Toukoshan formation, Cholan formation, Chinshui shale, Kueichulin formation, Guanyinshang formation, Talu shale and Peliao formation.
In this study, we used retrieved cores with different depths from meta-granite in the Hualien Heping and sedimentary rock in the Chang-Hua Coastal Industrial Park to evaluate the variation of three-dimensional in-situ stress with depth via anelastic strain recovery (ASR) method. Results show that the stress field is normal faulting with N-S extension in both places. In Hualien Heping, the maximum, intermedium and minimum principal stress gradient is 26MPa/km, 22MPa/km, and 19MPa/km, respectively. Their regression coefficients are all larger than 0.9. The gradient of differential stress is 7MPa/km. In the Chang-Hua Coastal Industrial Park, the maximum, intermedium and minimum principal stress gradient is 22MPa/km, 18MPa/km and 17MPa/km, respectively. The regression coefficients are over 0.8. The gradient of differential stress is 5 MPa/km. In addition, empirical equations of lateral stress coefficients and stress ratio deduced from ASR results can used to characterize the site aspects and evaluate the stress field nearby. Combining ASR results with rock mechanic data in the Chang-Hua Coastal Industrial Park can further estimate the maximum fluid pressure and the maximum injection pressure of carbon dioxide for rock fracturing.
Results of this study can be used to evaluate the application and feasibility of ASR in Taiwan. Hopefully, the assessment of in-situ stress via ASR on retrieved cores from borehole and foundation engineering can provide information for academic and engineering reference and utility.
| Identifer | oai:union.ndltd.org:TW/103NTNU5135017 |
| Date | January 2015 |
| Creators | Li, Wei-Cheng, 李偉誠 |
| Contributors | Yeh, En-Chao, 葉恩肇 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 228 |
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