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https://hdl.handle.net/11681/10859
Title: | Expert-opinion elicitation for the risk analysis of design-improvement alternatives to the Lindy Claiborne Boggs Lock and Dam |
Authors: | BMA Engineering, Inc. United States. Army. Corps of Engineers. New England District. Innovations for Navigation Projects Research Program (U.S.) Ayyub, Bilal M. Blair, Andrew Nyakaana. Patev, Robert C. |
Keywords: | Design alternatives Expert opinion Locks Hydraulic structures Probabilistic risk assessment Risk assessment Dams Elicitation Navigation project Reliability Uncertainties Delphi process Innovative construction Preliminary hazard analysis Risk analysis Lindy C. Boggs Lock and Dam Louisiana Red River |
Publisher: | Information Technology Laboratory (U.S.) Engineer Research and Development Center (U.S.) |
Series/Report no.: | ERDC/ITL TR 02-2. |
Description: | Technical Report Abstract: This report documents the expert-opinion elicitation performed to meet risk analysis needs of the lower lock approach sediment management improvement alternatives to the Lindy Claiborne Boggs Lock and Dam. A companion report (ERDC/ITL TR-02-1) describes the review and assessment of the Preliminary Hazard Analysis conducted for the alternatives. The Lindy C. Boggs Lock and Dam experiences large water-level fluctuations. To accommodate the large fluctuation of water levels, floating guide walls upstream and downstream of the lock were incorporated into the plans. To retain the riverside lock wall backfill, a concrete “T-wall” was constructed for a distance of 130 ft (approximately 40 m) perpendicular from the lock on the downstream end. Anticipating that sediment would deposit in the navigation channel underneath the downstream floating guide wall, provisions were included in the original plans in the form of an earthen dike and a composite “I-wall” (steel sheetpiling and concrete wall) on top of the dike. The I-wall was connected to the T-wall and continued 130 ft offset from and parallel to the floating guide wall for 1,100 ft (335 m). The purpose of the dike and I-wall was to divert the flow and sediment from the floating guide wall and the navigation channel, thus providing a slack-water lock approach channel. Nonetheless, an average of approximately 310,000 cu yd of silt has been removed annually from the lower lock approach channel at Lindy C. Boggs Lock and Dam. Three alternative improvements are proposed to control this sedimentation: a new fixed guide wall with dike removal, a new fixed guide wall with retention of the dike, and barrier extension and use of concrete panels. The U.S. Army Engineer District, Vicksburg, has the requirement to determine the probability of catastrophic failure during the construction and utilization phases of the lock-improvement alternatives, including potential catastrophic damage occurring to the floating guide wall pontoons while they are being removed, transported to and from their temporary storage area, and reinstalled. The tasks in every phase of each alternative are assessed for risk, examining associated initiating events, failure scenarios, occurrence probabilities, and associated consequences. Initiating events and failure scenarios are identified and enumerated. Consequences and occurrence probability are determined by expert-opinion elicitation, as documented in this report. Information related to failure probability and consequences is not available from historical records, prediction methods, or literature review. Expert-opinion elicitation provides a means of gaining information on these essential risk-related quantities. The expert-opinion elicitation process is a formal, heuristic process of obtaining information or answers to specific questions about certain quantities, called issues, such as failure rates (probability) and failure consequences. In this report, the different components of the expert-opinion elicitation process are described, the process itself is outlined, and the results are documented. |
Rights: | Approved for public release; distribution is unlimited. |
URI: | http://hdl.handle.net/11681/10859 |
Appears in Collections: | Technical Report |