Design Challenges
Subsurface exploration by geotechnical engineering company Modjeski and Masters showed thick deposits of low-density sand below the water table. Such loose sand might liquify during an earthquake. Several ways to reduce the risk were considered, including in-situ densification of the sands, but ultimately the foundations were changed to feature 12-foot-diameter (3.7 m), 120-foot-long (37 m) drilled piers founded in the limestone bedrock to support the bridge superstructure. The bedrock is 120 feet (37 m) below the surface on the Illinois side and between 30 and 60 feet (18 m) on the Missouri side.
Read more about this topic: New Mississippi River Bridge
Famous quotes containing the words design and/or challenges:
“Humility is often only the putting on of a submissiveness by which men hope to bring other people to submit to them; it is a more calculated sort of pride, which debases itself with a design of being exalted; and though this vice transform itself into a thousand several shapes, yet the disguise is never more effectual nor more capable of deceiving the world than when concealed under a form of humility.”
—François, Duc De La Rochefoucauld (1613–1680)
“A powerful idea communicates some of its strength to him who challenges it.”
—Marcel Proust (1871–1922)