Abstract The Chesapeake Bay Bridge, a $45,000,000 structure, dedicated July 30, 1952, extends 4.3 miles across Chesapeake Bay, linking Maryland's Western Shore with Del-marva Peninsula. Superstructure consists of simple and cantilever deck spans, 2920-foot suspension main bridge, and 1720 feet through cantilever span. Substructure is entirely on steel piles up to 135 feet long and penetrating to lowest elevation–203 feet M.S.L. Two alternate locations were investigated by 38 borings, totaling 7372 linear feet; the deepest reached elevation–355 feet. Representative grain-size analysis, time-consolidation, Atterburg Limit, compression, and related laboratory tests on 501 ordinary and 93 undisturbed samples furnished quantitative data for substructure design. To enable three-shift drilling, and eliminate shore-based survey crews and delays during periods of restricted low-level visibility, barges were positioned by use of special sextant charts which afforded virtually instantaneous graphical fixes based on observed angles between night-lighted, elevated shore signals. Two shore-to-shore geologic sections were developed, depicting unconsolidated Coastal Plain formations penetrated, including Recent and Pleistocene silts, sands, and gravels; the Aquia (Eocene); and the Monmouth, Matawan, and Magothy (Upper Cretaceous). Explorations of the drowned Pliocene (?) valley of the Susquehanna encountered 1.5 miles west of the Eastern Shore beneath 65-90 feet of water were of critical engineering importance and are of unique geologic interest. Former channel, approaching 5000 feet in width, bottom at elevation-170, and filled with up to 100 feet of highly compressible organic silt, necessitated use of longest piles on project. Integrated geologic and soils studies proved exceptionally valuable in all phases of the project.

Abstract An embankment on the new Ohio Turnpike, 35 feet high, started to fail on September 1, 1955, just a month prior to the date of opening of the highway. The toe of the north side of the embankment started to bulge, and cracks developed on the flanks and in the pavement. The situation was controlled by placing backfill on the toe and flank of the embankment, making the final slope 1 to 3, with an intermediate berm of 1 to 10. Grout was placed beneath the pavement to fill the voids caused by the slumping. Boreholes drilled through the embankment indicated that cause of failure was pore pressure and instability developed in lake beds underlying the embankment. Maximum pore pressures of 13 feet were observed, which in the ensuing months gradually declined.