A COMPACT DESIGN FOR SHAFT-TUNNEL JUNCTION ADOPTED FOR GREATER CAIRO METRO LINE 3: DESIGN ASPECTS AND USE OF ADVANCED NUMERICAL METHODS

摘要

A new concept was recently introduced for the design of shaft-tunnel junctionsrnon the Greater Cairo metro system, whereby no ground improvement and no crosspassagesrnare necessary. The principle lies in driving the TBM to intercept a circularrnslurry wall. The shaft can then be excavated in several stages, allowing for the constructionrnof a concrete portal. While this approach entails savings, it requires adequaterndetailing of re-bars and shear connectors. Advanced 3D numerical modelling is used tornassess structural forces for design. This example illustrates how advances in constructionrnmethods can be stimulated through improvements in the analytical tools.