Digitized by Kansas Correctional Industries

Due to the scarcity of land at coastal regions around the world, land reclamation is commonly carried out for the future expansion of various infrastructure facilities. Marine clay is present at the coastal regions of Southeast Asia. Land reclamation on this highly compressible soil foundation often requires the use of soil improvement works to eliminate significant future settlements from occurring. The combination of prefabricated vertical drains with preloading is one of the most widely used ground improvement methods in land reclamation projects. The best means available for field measurement and back-analysis of the marine clay geotechnical characteristics under reclamation fills is by carrying out extensive field instrumentation and in-situ tests. In-situ testing of marine clay was carried out at a test site. In-situ penetration testing was used to analyse the degree of consolidation, the improved shear strengths, overconsolidation ratio and the effective stress of marine clay prior to reclamation as well as after surcharge loading. In-situ dissipation testing was used to determine the coefficient of consolidation due to horizontal flow and horizontal hydraulic conductivity of the marine clay prior to reclamation as well as after surcharge loading. The in-situ penetration and dissipation tests were carried out by means of the field vane shear, piezocone, dilatometer, self-boring pressuremeter and BAT permeameter. Field instrumentation methods, assessment and hack-analysis of marine clay behaviour under reclamation fills forms the crux of this research. / The factors that affect the field instrumentation assessment of marine clays treated with prefabricated vertical drains, forms an integral part of this research study. Settlement gauges and piezometers were used to monitor the performance of the vertical drains and to assess the degree of consolidation of the improved soil at two case study sites. The field settlement data were back-analysed by the Asaoka and Hyperbolic methods to predict the ultimate settlement of the reclaimed land under the surcharge fill. Back-analysis of the field settlement and piezometer monitoring data also enabled the coefficient of consolidation due to horizontal flow to be closely estimated. Finite element modeling of marine clay and prefabricated vertical drains was carried out and compared with the field surface settlement results at the two case study sites.

Excessive settlement and foundation instability are some of the main problems commonly encountered in fills and embankment structures built on a soft soil of low bearing capacity.The Expanded Polystyrene(EPS)replacement method, by partially or fully replacing the conventional fill material with extremely lightweight EPS geofoam, may solve these problems. In this thesis, experimental and theoretical work have been carried out to investigate the behaviour of EPS under various loading conditions in geotechnical applications and the effectiveness of EPS replacement technique has been studied using numerical models.Several tests were performed for this study and the results of these tests are given / Doctor of Philosophy (PhD)

This thesis presents an improved method for dynamic force computation applicable to both electrostatic and electromagnetic conductors with complex 3D geometries. During the transient simulation of electrostatic actuated MEMS, the positions of the conductors as well as the potential applied to the conductors may change, necessitating recalculation of electrostatic forces at each time step of computation. Similarly, during the simulation of electromagnetic actuated MEMS, the current re-distribution in the conductors requires recalculation of electromagnetic forces at each time step. In this thesis, a simple method based on the principles of fast multipole algorithm is explored to effectively recalculate the potential coefficients to compute the surface charges and thereby forces during transient simulation of electrostatic conductors. The proposed method improves the speed of electrostatic force computation by 15 - 60% at each time step, depending on the displacement, with an error less than 3%. Electromagnetic forces are also computed by the same method. In addition, an efficient method is also presented for electrostatic analysis of dummy metal filled interconnects.

Thesis (M.S.)--West Virginia University, 2002. / Title from document title page. Document formatted into pages; contains viii, 152 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 87-91).

Thesis (M. Sc.)--University of Hong Kong, 2001. / Includes bibliographical references (leaves 121-123).

Thesis (M. Phil.)--University of Hong Kong, 1979.

Thesis (M. Phil.)--University of Hong Kong, 1979.

No description available.

Thesis (D.Eng.)--University of Delaware, 2008. / Principal faculty advisor: Paul T. Imhoff, Dept. of Civil and Environmental Engineering. Includes bibliographical references.