Figure D-8: Pile cap abutment with micropiles, existing walls to remain
3. Abutment Wall with Drilled Shafts Behind Existing Walls Similar to abutment option 1, with a single row of drilled shaft foundations behind the existing retaining walls and associated reinforcing zone.
Figure D-9: Offset drilled shaft abutment, existing walls to remain
The pros and cons of each approach are listed in the previous technical analysis; however, only option 1 proposes removing and replacing the existing retaining walls. Option 1 would provide an opportunity to construct new side barrier walls which accommodate a full width shoulder and would still likely have a smaller construction footprint over the other two options. Under option 1 the proposed drilled shafts could be offset from the existing retaining wall such that a full width shoulder could be
D-11
Made with FlippingBook Ebook Creator