No description available.

In the South African mining industry, the design of tunnel support systems is generally based on empirical methodologies that consider rockmass characteristics as well as the type of loading (e.g. seismic) that the excavation experiences. The design methodologies are by no means infallible, and work is continually being conducted to improve the classification of excavation conditions and thereby improve the selection of a suitable support system. This study is concerned with finding a means to monitor the installed support units rather than with improving the classification methodologies. It is postulated that with the extraction of accurate information describing the state of any support unit at any given time, areas of instability in the tunnel can be readily identified and strengthened~ Also, the information gathered as to the behaviour of the support units in a particular region can be used to assist in understanding the environmental characteristics of that region (rockmass, loading, etc.). A material survey was conducted to identify suitable candidates that could feasibly be used in either a passive (feedback when interrogated) or active (constant feedback) structural health monitoring system. The preferred candidates identified in this study are the group of passive smart materials referred to as TRIP steels, which are a subset of strain memory alloys. TRIP steels exhibit microstructural changes from paramagnetic austenite to ferromagnetic martensite as a function of increasing deformation at a given temperature.. The strength of the magnetic field at critical locations provides an indication as to the health state of the component. Because of their high strengths and ductility, TRIP steels can be used as what amounts to a self-monitoring support unit (interrogation apparatus required). Finite element methods are a practical means of predicting the mechanical and magnetostatic behaviour of TRIP steel structural members once material equations have been established by experiment. / Thesis (Ph.D.)-University of Natal, Durban, 2003.

No description available.

No description available.

The Bolu Tunnels lie along Trans European Motorway (TEM) which is connecting Eastern Europe with the Middle East. The tunnels are approximately 3.0 km long, 40 m apart and have excavated cross sections more than 200 m2. In construction, New Austrian Tunneling Method (NATM) was used in soft ground. Due to the challenging ground conditions, many problems have been encountered during tunnelling. To solve these problems special construction techniques were adapted. To simulate and demonstrate the effectiveness of these construction techniques, 2D and 3D Finite Element Methods are utilized in this study. Through comparison between 2D and 3D modelling of advance of Bolu Tunnels, respective merits of these two approaches are investigated and the conditions under which shortcomings of the 2D approach become serious are identified.

Thesis (B.Sc. (Honours)) - Australian National University, 1997. / Title from title screen (viewed on May 20, 2002). "A thesis submitted in partial fulfilment of the requirements for the Degree of Bachelor of Science (Honours)"--Title screen. Bibliography: p. 64-66. Available full text via the internet.

Thesis (Ph.D.)--Hong Kong University of Science and Technology, 2008. / Includes bibliographical references (leaves 135-139). Also available in electronic version.

Thesis (Ph. D.)--West Virginia University, 2008. / Title from document title page. Document formatted into pages; contains xv, 134 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 133-134).

Thesis (Ph. D.)--Rutgers University, 2010. / "Graduate Program in Mechanical and Aerospace Engineering." Includes bibliographical references (p. 86-90).

Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2004. / Includes bibliographical references (leaves 187-194). Also available in electronic version. Access restricted to campus users.