Design and analysis of tunnel cross passage for rail and road tunnel with emphasis on tunnels with segmental lining | |
| Author | Jayasiri, Jayasiri Mudiyanselage Nilan Sachintha |
| Call Number | AIT Thesis no.GE-19-07 |
| Subject(s) | Tunnels--Design and construction Geology--Thailand--Bangkok Finite element method |
| 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 | With the increasing popularity of rail and road tunnels, significant number of tunnel accidents and emergency situations have been recorded during the past few decades. Hence, building railway and road tunnels calls the need to construct cross passages at regular intervals. On the single pass (one layer) lining system, the segmental lining provides both initial (immediate) ground support for the excavation and final tunnel support. Formation of an opening for breakout of cross passage from the TBM tunnel will alter the simple lining behavior to a more complex one. Hence, strengthening of the tunnel lining will be required. In order to do so, it is important to have a better understanding about the development of loads during construction when the design work is carried out. 3D Finite Element and 3D Shell Spring analysis are two widely adopted methods to quantify the loads induced in the tunnel lining. In this study, the effectiveness of using 3D finite element analysis and 3D shell spring model to evaluate the stress redistribution occurring in the segmental lining due to cross passage excavation was assessed. For this purpose, member forces were derived for two possible construction sequences using above mentioned methods based on a case in Bangkok, Thailand where two cross passages were being constructed between a bored tunnel and a shaft. The analysis was followed by a comparative study to discuss the effectiveness of using each method in each construction sequence. According to the results, it was found out that the both methods are appropriate to quantify the member forces whenever the cross passage is being constructed from the bored tunnel to the shaft. However, 3D shell spring model is not suitable to use when the cross passage is being constructed from shaft to the bored tunnel as it is unable to capture the effect of the constructed cross passage. Furthermore, it was found that the presence of circumferential joints in tunnel lining significantly affects the load transfer mechanism between the opened ring and the adjacent fully enclosed ring. This effect can be readily taken into account in the 3D shell spring model. Moreover, this study concludes that the design of temporary support can also be conducted relatively easily by the 3D shell spring model when compared to 3D Finite Element method. |
| Year | 2020 |
| Type | Thesis |
| School | School of Engineering and Technology (SET) |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Geotechnical Engineering (GE) |
| Chairperson(s) | Chao, Kuo-Chieh; |
| Examination Committee(s) | Noppadol Phien-wej;Pham Huy Giao; |
| Scholarship Donor(s) | Asian Institute of Technology Fellowship; |
| Degree | Thesis (M. Eng.) - Asian Institute of Technology, 2020 |