Atlas, as a subconsultant, recently completed the Phase II Structural engineering design for the temporary and permanent retaining walls in segment 9 of the corridor and the 71st Street viaduct bridge. The design of the bridge included deck plate girders with diaphragms, drilled shaft foundations, and were designed for a Cooper E 90 loading. The bearing design included consideration of horizontal rotations due to the large width of the deck to allow horizontal rotation of the deck. The retaining wall work included design of permanent retaining walls and temporary earth retention systems. The design included construction staging plans by using temporary retaining walls to separate the temporary shoo-fly tracks from the final rail alignment to allow uninterrupted rail service. The permanent retaining walls were designed to accommodate railroad signal structures and associated utilities.