The application of three-dimensional seepage analysis to predict the behavior of groundwater and ground surface settlement in shallow tunnel excavation | |
| Author | Keeratikan Piriyakul |
| Call Number | AIT Thesis no. GE-98-19 |
| Subject(s) | Seepage Tunneling |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Civil Engineering |
| Publisher | Asian Institute of Technology |
| Abstract | The development and extension of large cities creates a need for multiple shallow tunnels. Prediction of the ground settlement caused by tunnel settlement excavation is a major engineering challenge. A numerical simulation using a finite element method was implemented in the aim of developing a procedure to predict the movement induced by tunnelling. To predict the ground surface settlement, the theory of seepage analysis and consolidation were adopted. When groundwater was drawn down due to tunnel excavation, the ground surface subsided. Therefore, the 3-D seepage analysis was adopted to predict the behavior of groundwater during tunnel excavation. This research proposes the suitable method for predicting the influence of groundwater such as draw down of groundwater and predicting the ground surface settlement around urban tunnels. To check the capability of 3-D seepage analysis, the 2-D seepage analysis was adopted. The results show that it is more effective to apply the 3-D unsteady seepage flow analysis for predicting the behavior of the groundwater flow due to shallow urban tunnel excavation. It has become necessarily to adopt the 3-D analysis for predicting the influence on the hydrological environment at urban tunnel. After predicting the behavior of groundwater, for instance the draw down of groundwater, the 1-D consolidation theory was adopted to predict the behavior of ground surface settlement. The results being shown in the 3-D seepage analysis can simulate the characteristics of tunnel excavation, which are the progress of tunnel surface and sequent excavation procedure. From large scale model results, the ground surface settlement by means of 2-D seepage analysis is steeper than 3-D seepage analysis and the maximum of ground surface settlement by 2-D seepage analysis is greater than 3-D seepage analysis. Because of 2-D seepage analysis has more effects of soil layers above tunnel and limitation of the dominated flow direction. Therefore, the prediction of ground surface settlement by means of 2-D seepage analysis tends to become over estimated method. By this reason, the 3-D seepage analysis is suitable to apply in actual excavation than 2-D seepage analysis. |
| Year | 1999 |
| Type | Thesis |
| School | School of Civil Engineering |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Geotechnical Engineering (GE) |
| Chairperson(s) | Ohtsu, Hiroyasu; |
| Examination Committee(s) | Balasubramaniam, A. S.;Der Guey, Lin;Noppadol Phien-Wej; |
| Scholarship Donor(s) | Asian Institute of Technology Partial Scholarship; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1999 |