Risk Management of Earthworks Using GeoQ.

Large budget overruns within infrastructure projects seem to become common practise over the last decades. In the Netherlands and also world-wide these overruns of public funds have become less and less acceptable. Within the construction industry awareness grows that failure costs have to be decreased significantly. Studies to assess failure costs conclude with figures of 4 to 9 billion Euro annually for a small country as the Netherlands only. Approximately 50% of these failure costs are directly or indirectly related to sub-surface conditions. The question was raised whether one should speak of a crises of the underground or of a managed risk. In answer to this question, GeoDelft has developed a general approach named GeoQ to deal with sub-surface risks and thus control total project costs. Very often, cost overruns during the construction of some large infrastructure project can be back traced to little or no attention for subsurface related risks in the early plan or design phase of the project. To enable a fair discussion on subsurface related risks in every phase of the project, the GeoQ approach strives to bring transparency in the many implicit decisions taken in a project. The first cornerstone of the GeoQ approach is a cyclic, risk based approach of design, and construction in every phase of a project. The second cornerstone is to mobilise all relevant information and knowledge to enable continuity of information between the various project phases. This will lead to an improvement of the total quality of the project and a related strong decrease of unexpected cost. Stimulated by a new, experimental contractual relation between client and contractor, construction of the Sliedrecht-Gorinchem section of the Betuweroute freight railway demonstrates that awareness of subsurface risk enables value engineering resulting in significant optimisations. In this project the GeoQ approach, supported with some state-ofthe-art design and monitoring tools, formed the basis for savings up to 10 % of the total project costs (e.g. 20 million Euro). This success was realised within a very tight contractual time frame, in an area known for its extremely soft soil conditions. For the covering abstract see ITRD E135448.