ISRM 2023 - PUBLICATIONS

T02: Comparison of international tunnelling contractsDavide MERLINI (1), Daniele STOCKER (1), Matteo FALANESCA (1), Matthias NEUENSCHWANDER (2)1: Pini Group SA, Switzerland; 2: Neuenschwander Consulting Engineers, SwitzerlandCase Histories of contractual management of geological risksThe geo-uncertainty of underground projects most often leads to differences between foreseen and encountered geo-conditions. Dealing with this uncertainty is a major challenge as it often raises claims and complex contractual problems mostly related to the construction programme. Over the last years, contract management tools have been developed in order to manage this risk. One of the key aspects for the successful delivery is the elaboration of a mechanism to adjust the time for completion. The clear allocation of duties and risks between the Employer and the Contractor, together with its proper integration in the contractual frame-work, play a crucial role. This paper presents cases of implementation of such a contractual mechanism in several Countries, standard forms and excavation methods together with the comparison with the FIDIC standard. | Risk management, Forms of contract, Schedule of Baselines, FIDIC Standard
T02: Comparison of international tunnelling contractsCarl Philipp FRIEDINGER (1), Klaus MITTEREGGER (2), Philip SANDER (1,3)1: University der Bundeswehr Munich, Neubiberg, Germany; 2: TIWAG-Tiroler Wasserkraft AG, Innsbruck, Austria; 3: RiskConsult GmbH, Innsbruck, AustriaProbabilistic Analysis of the Delivery Models Unit Price and Alliance applied at the Project Gemeinschaftskraftwerk Inn with Focus on the Construction TimeInnovative delivery models attempt to deliver major construction projects within budget and on time. However, proving their efficiency is difficult because of a missing base for comparing innovative and traditional delivery models. Therefore, a common ground is mandatory, as given in the “Gemeinschaftskraftwerk Inn” (GKI). Part of the GKI is a 23.5 km long headrace tunnel. The excavations started in the design-bid-build model with a unit price contract, which was terminated during construction by mutual agreement. The alliance contract was chosen to continue the tunnel advance with a new contractor. Only key personnel was exchanged. That allows a unique direct comparison of both delivery models. A probabilistic analysis was conducted. In principle, probabilistic models of the excavations were introduced to compare the construction time in the two different contract models. The key finding is that the construction time is 15 % to 22 % faster using the alliance delivery model. | alliance contract, Gemeinschaftskraftwerk Inn, innovative delivery models, probabilistic analysis, TIWAG alliancing contract