Canadian-born Dr Suzanne Lacasse graduated from high school at the age of 13. After completing a Bachelor of Arts degree in 1967 she went to the University of Montreal where she studied civil engineering at Ecole Polytechnique. She obtained her PhD in 1976.
While lecturer and head of the geotechnical laboratory at MIT in 1978, she accepted a oneyear post-doctoral fellowship at the Norwegian Geotechnical Institute (NGI), where she became a permanent member of staff in 1980. She combined her position at NGI with a visiting lectureship at MIT until 1982. She became NGI's managing director in 1991.
During the early part of her career, Lacasse concentrated on geotechnical laboratory techniques, soil behaviour studies and insitu investigation methods, publishing a number of articles and reports. She then worked in foundation engineering design for onshore and offshore structures involving soil slope stability evaluation and improvement, and development of calculation procedures. She was a key member of the NGI-team developing practical design analysis procedures for offshore platforms subjected to storm loading. More recently, she developed and applied probabilistic analyses to assist in foundation design and decision process.
Increasing demand for underground construction in cities, sustainable transportation systems, and for modernised infrastructure for freshwater, sewerage and waste disposal pose new challenges to geotechnical engineers. Old underground water pipes or gas lines cause flooding and water cut-offs, resulting in street cave-ins and breaks in adjacent lines. In the USA, there are thousands of kilometres of old pipelines and they leak more oil each year than the volume that was spilled from the Exxon Valdez oil tanker that ran aground off the coast of Alaska in 1989.
The contribution of geotechnical engineering to infrastructure is indispensable, yet often underestimated by public, government and even the profession itself.
Geotechnical engineers influence alignment, planning, design and maintenance of traffic and transport arteries. They help decide location and orientation of runways and are the key to the safe foundation of coastal and offshore structures.
Geotechnical engineers have the required expertise for the evaluation of the risks involved in their designs as they have the knowledge, judgement and experience to evaluate the uncertainties involved.
The theme lecture aims to provide an overview of recent accomplishments and develop an outlook and prospect for the future. Its role is to prepare an arena for discussion on two main topics:
l Road, railway and runway construction l Coastal and marine engineering.
Faced with such a vast subject, achievements and challenges are discussed in terms of four allencompassing objectives of our profession:
l Engineering more economical solutions l Developing improved and safer transportation solutions lEncouraging innovative solutions, also those adapted from offshore practice l Protecting and preserving the environment.
To meet these challenges, an alliance of good practice with the results of recent research is required, and at times it is the approach that will offer the most cost effective alternative.
Achievements, future directions as well as challenges are illustrated with examples from transportation infra- structure and from coastal and marine engineering. For example, improved site investigations will lead to more economical solutions in difficult soil conditions and improved tunnel performance in terms of leakage control.
In both cases, the solutions are aimed at preserving the environment. Offshore solutions developed for sometimes extreme environmental conditions now present attractive options for, for example, bridges, foundation of pipelines and windmills, harbour installations and breakwaters.
Directions for the profession are also given.
Perhaps it is time to be critical of how the profession is ensuring its future. Commun- ication needs to be improved, we need to thrive on change, we must offer attractive and varied career prospects to new geo-engineers and we need to focus on both the art of engineering and engineering art.
On the technology side, we need to:
l achieve a more effective dialogue and cooperation among geologists, geophysicists and the geotechnical engineers l increase efforts to evaluate the risk of natural hazards and develop mitigating measures and improved methods for the analysis of slopes l improve methods for the analysis of and countermeasures against the effect of vibrations, eg due to high speed trains l meet with ingenuity the challenge of offshore geohazards and seafloor instability l include automatically the environmental component to our foundation solutions l do consequence analysis of alternatives and increasingly quantify the risks involved l contribute to increased close co-operation among client-designer- consultant-contractor.
Geotechnical engineering adds value by saving lives, preserving the environment, improving performance, reducing costs and contributing of exploiting natural resources in a responsible manner. We need to tell others.