Reliability-based design consists the basis of AK’s philosophy to design. The only reliable evaluation of cost and duration for the construction of an underground structure is that that is proceeded by a thorough risk analysis. Even if the ground is accurately investigated, it is always associated with inherent uncertainty and variability that introduce risk to a project. Knowing the magnitude of these risks (likelihood and consequences) is of utmost importance in the decision-making process of underground structures design and in defining adequate countermeasures for residual risks management.
AK has been active for the development of specific applications for risk analysis, collaborating amongst with the developers of the DAT software of MIT and EPFL.
DAT (and associated codes SIMSUPER and SIMJAVA)
The software DAT (Decision Aids for Tunneling) has been developed by the Massachusetts Institute of Technology (MIT) and the ‘Ecole Polytechnique de Lausanne (EPFL) that allows for the probabilistic evaluation of the costs, durations and necessary resources for the construction of tunnels DAT is based on information that are used by the geologists, engineers, contractors both during the design and construction phases of a project. This information includes: geologic and geomechanical longitudinal sections, excavation methods, advance rates, costs, and resources. The most important characteristic of DAT is that it permits to associate to geotechnical conditions and construction methods variability permitting in this manner to evaluate the overall uncertainty related to the construction of a project underground as well as to quantify the value for the project of additional site investigations.
Therefore, the use of DAT permits to evaluate in a scientific, consistent and documented manner the impact on project duration and cost of alignment alternatives, different excavation technologies, various planning alternatives for the construction of a project for a given geotechnical context and its degree of reliability. The use of DAT does not conclude with the design phase; on the contrary it permits to revise forecasts based on the encountered geologu, actual advance rates and actual project costs allowing for on time decisions to be taken.
With respect to other software (that are simple spreadsheet applications) DAT is the product of a continuous research and development (started more than 20 years ago) from two academic institutions (MIT and EPFL) that are synonyms of engineering excellence worldwide.
- Cost-benefit analysis of site investigation plans;
- Construction simulation of complex projects;
- Comparative analysis of different project configurations;
- Comparative evaluations of different excavation methods.