| Author | Nguyen Minh Son |
| Note | A research study submitted in partial fulfillment of the requirements for the degree of Master of Engineering (Professional) in Geotechnical and Earth Resources Engineering with Area of specialization in Geotechnical Engineering and Management |
| Publisher | Asian Institute of Technology |
| Abstract | The Urban Mass Rapid Transit (UMRT) line No.2 is a part of the UMRT network in Hanoi connects the new city with the core city of Hanoi. Land subsidence due to groundwater withdrawal had been researched and observed since the early 90s of the last century. However, monitoring techniques for land subsidence are poor and not sufficient to reflect the real status of ground subsidence in Hanoi. And whether land subsidence due to groundwater withdrawal impacts the UMRT network in Hanoi. It is a question that is being addressed and needs to be clarified.
The main purpose of this study aims to preliminary estimate the land subsidence due to ground water drawdown along the UMRT line No.2 in Hanoi city by using Differential InSAR (DInSAR). A total of 07 images were collected and used for DInSAR processing from the Copernicus Access Hub provided by European Space Agency (ESA). There were 06 stacks of Interferogram with 21 Interferograms had been formed for DInSAR processing, and 03 best Interferograms from 02 stacks were chosen for estimation of land subsidence for the study area. Land subsidence analysis by using an 1_D FEM consolidation with the help of TZP program (Giao, 1997) was also reviewed and performed for the study area. Based on the groundwater drawdown data collected by Minh (2007), the drawdown values at each borehole location along the UMRT in 2016 were predicted and used as the boundary conditions for TZP program analysis. The input data for TZP program were prepared based on the geotechnical characterization of subsoil performed by Hue (2017).
The comparison of results obtained between two methods shows a similar trend of subsidence rate along the UMRT, which increase from BH01 to BH30. In DInSAR method, the results obtained from the Interferogram, i.e., 06Oct2015_03Jul2017 are very similar and consistent with that from 1-D FEM consolidation analysis. On the other hand, the results received from two Interferograms, i.e., 02Jul2015_03Apr2016 and 02Jul2015_12Oct2016 of the six Interferograms stack is different from that of FEM consolidation analysis. The subsidence rate at all borehole locations retrieved from this stack is larger than that of FEM consolidation analysis. This indicates that the results obtained from the six Interferogram stack should not be reliable due to the possible effects of atmosphere and decorrelation noises. The relationship between two data types from DInSAR method (with the Interferogram 06Oct2015_03Jul2017) and 1-D FEM consolidation analysis is computed and given with the correlation value R2 = 0.96.
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| Year | 2018 |
| Type | Research Study Project Report (RSPR) |
| School | School of Engineering and Technology (SET) |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Geotechnical Engineering and Management (Master Engineering (Professional)) (PME - GEPG) |
| Chairperson(s) | Giao, Pham Huy ; |
| Examination Committee(s) | Kuo-Chieh Chao;Virdis, Salvatore G.P. ; |
| Scholarship Donor(s) | Geotech International Pte. Ltd., Singapore ; |