CONSTRUCTION PLAN OF A DIVERSION TUNNEL TO BE CONSTRUCTED BENEATH AND CROSSING THE RAILWAY TUNNEL

A diversion tunnel will be constructed which crosses the existing railway tunnel at a depth of 2.0 m right under the latter tunnel. It is feared that when the diversion tunnel to be constructed near the existing railway tunnel may exercise adverse effects such as deformation and disturbance on the railway tunnel. Further, it has become a first priority to ensure safe operation of trains, and in addition, assurance of long-term safety of train operation is demanded. Since the example of the above-mentioned construction work is very rare, sufficient but not-excessive examinations have been made on the survey, analyses, designs and construction plans. The results are shown in this paper. For the covering abstract see ITRD E108195.