A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering of the Asian Institute of Technology, Bangkok, Thailand

Thesis (M.Eng.) - Asian Institute of Technology, 1978

This thesis deals with the coefficient of lateral earth pressure at rest, earth pressure theories against rigid retaining structures, analytical and design methods of sheet pile wall and some of the recent contributions to braced excavation by means of the thorough literature review in order to give some of the fundamental knowledge on the earth retaining structures for future study. The finite element analyses of the slurry trench excavation and braced excavation were made for Bangkok subsoil profile in the later part of this study. The results of the linear and the non- linear analyses of the slurry trench excavation showed that the modulus of elasticity and the slurry density had the greatest influence on the deformation behaviour of all parameters studied. The slurry density was found to have the greatest influence on thee overall behaviour of the excavation. As far as the factors of safety are concerned, there was virtually no difference between the linear and the non-linear analyses below the mid-depth of the excavation in general. The finite element analysis of braced excavation showed that the upper two struts could be removed without significantly affecting the performance of the excavation taken to a deeper depth (>8 m) in Bangkok clay and that maximum lateral and vertical deformations of braced excavation of 10 m depth were extremely greater than those of the slurry trench excavation of the same depth. The finite element method showed its ability to predict lateral and vertical deformations, pore pressure reductions, strength mobilization, struts loads, pile deflections, etc., even though there is a problem of the high accuracy to be achieved.