Three dimensional analysis of ground movement in EPB shield in Bangkok | |
| Author | Hong, Chang-pyo |
| Call Number | AIT Thesis no.GE-04-13 |
| Subject(s) | Tunneling--Thailand--Bangkok Numerical analysis Finite differences Earth movements--Thailand--Bangkok |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Engineering and Technology |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. GE-04-13 |
| Abstract | The ground behavior due to shield tunnelling in Bangkok MRTA was investigated using the three-dimensional finite difference method program FLAC3D assuming an elastic-plastic model according to the Mohr-Coulomb criterion for the soil material with undrained deformation of the ground. The ground movements from tunnelling were explored with respect to influencing factors, namely: TBM face pressures, ground stress condition in terms of the coefficient of effective lateral earth pressure, the soil type which was excavated by EPB shield, initial ground pore pressure condition, and soil strength parameters. There were clear correlations between ground movement on tunnel face and behind shield. Effective lateral earth pressure was the main affection of the ground movement on tunnel face and the difference of the effective vertical and lateral earth pressure caused large stress concentration which governed the ground loss behind the shield. For this reason, the ground loss on tunnel face was smaller but the ground loss behind shield machine was larger in Bangkok Pore pressure condition, and the non-uniform stress condition caused bigger settlement than uniform stress in case that the ground movement was dominant behind shield machine, not on the tunnel face. Large settlements occurred in the case where a clay layer existed in the lower part of the tunnel face in the North of Bangkok MRTA. There was in agreement between numerical analysis and measured data on the conclusion of OReilly and New (1982) that for most cases, i = 0.5Z irrespective of whether the tunnel was in soft or stiff clays. Numerical analysis was applied to instrumented section in North of Bangkok MRTA for the comparison. The FLAC3D prediction had been verified in that the predicted surface settlement was close to the monitoring data and empirical results with the appropriated of the workmanship factor ( 0.3Gp) for the North Bangkok MRTA Zone 23. |
| Year | 2005 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. GE-04-13 |
| Type | Thesis |
| School | School of Engineering and Technology (SET) |
| Department | Other Field of Studies (No Department) |
| Academic Program/FoS | Geotechnical Engineering (GE) |
| Chairperson(s) | Noppadol Phien-wej;Park, Kyung Ho; |
| Examination Committee(s) | Bergado, Dennes T.; |
| Scholarship Donor(s) | Asian Institute of Technology Fellowship; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 2005 |