GEOLOGICAL CONDITIONS AT PRELIMINARY TUNNEL DESIGN STAGE AND CONSTRUCTION STAGE: AN EVALUATION AND ASSESSMENT

Abstract

This study highlights the reasons of disagreement between the preliminary tunnel design and design at construction stage through the geological investigations at both stages. For this purpose, the geological details for three existing tunnels at both stages were investigated. Data from elastic wave velocity, geological survey details and interviews and answers to questionnaires from several design and construction engineers were considered for the evaluation and assessment. The reasons for disagreement were determind comparing the items differed at preliminary design stage and design at construction stage for each tunnel site and interpretation from geological engineers.