ABSTRACT
The Hudson River Twin 7.69-m (25.2-ft) ID TBM Tunnels in New York-New Jersey, USA, are to be connected by 9 cross-passages across the 2,257-m (7,400-ft) long alignment which includes the 1,678-m (5,500-ft) river crossing. The stratigraphy varies significantly along this length putting some cross-passages in soft soil, and others in sound or decomposed rock, all under a significant water head. The cross-passages are characterized by variable geometries and sizes with their dimensions consistently exceeding half a tunnel diameter. In addition to ground loads, their design must consider various other loads including train, flooding and seismic loads. Simplified and refined numerical models were developed to assist the design and to account for the complex geometries, loading and ground conditions. This study provides an overview of the cross-passages geometries and conditions, numerical modeling, and structural design. It also describes important techniques used in modeling elements and evaluating their results.
