Many excavations and tunnels experience problems and instability caused by uncontrolled groundwater inflows or pressures. Groundwater control measures are used to overcome these problems and create stable and workably dry conditions below groundwater level.

A key challenge for designers is that the performance of the various different techniques is strongly influenced by the hydrogeological conditions at a site. Furthermore, the available ground investigation data may have data gaps or considerable uncertainty regarding key parameters such as permeability or hydraulic boundary conditions. This means that, when working with real-world data sets there are some groundwater problems where analysis involves so many assumptions and uncertainties that the design outcomes are of little practical value.

This lecture will discuss how thinking conceptual about groundwater problems can be of great benefit when developing of groundwater control schemes, and that a robust conceptual model helps reduce the risk of designs being developed using inappropriate techniques. Examples will be given of cases where developing a conceptual understanding of groundwater conditions was vital in developing practical engineering solutions.

Dr Martin Preene is widely acknowledged as an expert in the investigation, design and implementation of temporary works groundwater control for construction projects. A civil engineer by first training, he is both a Chartered Civil Engineer and a Chartered Geologist. He has 35 years’ experience with both contractors and consultants, helping to deliver practical solutions to groundwater problems, and has worked on projects in more than 40 countries. He works as a Technical Director at Richter Associates where his focus is on integrating groundwater control into wider temporary works solutions.

Martin is a former Chairman of the British Geotechnical Association, and is author or co-author of more than 70 technical publications, including CIRIA publication “Groundwater Control – Design and Practice” (C750) and the textbook “Groundwater Lowering in Construction: A Practical Guide to Dewatering”, now in its 3^rd edition. He has given invited lectures to a number of societies and worked with several universities as visiting lecturer and external examiner.