| Author | Ng, Hoe Boon |
| Call Number | AIT Thesis no. GE-98-26 |
| Subject(s) | Excavation--Taiwan--Taipei
|
| Note | A thesis proposal submitted in partial fulfillment of the requirements for the degree of
Master of Engineering, School of Civil Engineering |
| Publisher | Asian Institute of Technology |
| Abstract | Finite element analyses are used to study the performance of diaphragm walls for
top-down deep excavation in Taipei subsoil. A two-dimensional finite element program,
PLAXIS was used for back-analyzing the performance of a "Full Scale" top-down deep
excavation in Taipei. In which, an undrained analysis incorporated with groundwater
calculation was performed. The results of FEM prediction were found in close agreement
with the field observation in term of lateral wall movement, ground surface settlement,
lateral earth pressure distribution, bending moments of diaphragm wall and pore water
pressure at various zones of excavation. Meanwhile, stress paths at various zones of
excavation are established for deep excavation in Taipei subsoil. Finally, a series of
parametric studies were carried out based on the back-analyzed parameters and average
properties of Taipei subsoil to investigate the effects of wall and support stiffness, wall
embedment depth, depth of unsupported excavation and surcharge load on the
performance of diaphragm walls. The aspects of wall performance evaluated in the
parametric studies including lateral wall movement, ground surface settlements and wall
bending moments.
The increasing of wall stiffness is not effective in limiting the development of
wall and ground movement. The early installation of lateral support could minimize the
potentially large wall and ground movements. Besides, an unsupported excavation could
induce negative wall bending moment that is generally increased with the unsupported
depth. Furthermore, the support stiffness has only a minor effect on the performance of a
top-down deep excavation in Taipei subsoil. Moreover, increasing the wall penetration
depth could not help in reducing the wall movement. Finally, the existence of surcharge
adjacent to the excavation is necessary to be considered as it could significantly affect the
magnitude and shape of wall deformation and ground settlement. |
| 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) | Der-Guey Lin;Otsu, Hiroyasu; |
| Examination Committee(s) | Balasubramaniam, A. S.; |
| Scholarship Donor(s) | Partial Scholarship;Lee Foundation; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1999 |