Dredging Operations Technical Support Program: Engineering Design andEnvironmental Assessment of Dredged Material Overflow from Hydraulically Filled Hopper Barges in Mobile Bay, Alabama

摘要

Barge overflow was investigated as a cost-effective option for future dredgingneeds in Mobile Bay, Alabama. Tests of hopper barge loading characteristics with overflow operations were conducted in Mobile Bay. In theory, overflow would allow denser materials to settle within the barge while less dense materials were shunted overboard. Increased density of barge-held materials would then translate to cost savings via a reduced requirement for transport to a distant approved disposal site. Thus, one major objective of the study was an engineering evaluation of equipment performance during the tests. A second major objective was to obtain field data for an assessment of the environmental consequences of overflow. In support of both objectives, modeling studies were performed to simulate overflows that would be associated with routine dredging operations. Eight separate tests were conducted. Three tests occurred at a site in lower Mobile Bay, and five tests at an upper bay site. Three tests (one lower bay, two upper bay) involved dredging in maintenance materials, and five tests (two lower bay, three upper bay) involved new work or deepening materials. (JES)