FIELD TESTING AND STRUCTURAL ANALYSIS OF VERTICAL LIFT LOCK GATES

Abstract : The objectives of this study was to measure the behavior of vertical lift lock gates experimentally and to develop modeling and analysis procedures for the evaluation of existing gates and design of new gates and design of new gates. In this study, lift gates at Mississippi River Lock 27 and Locks and Dam 26 were investigated. The gates were instrumented and tested under various loading conditions and analytical models were developed to simulate structural response of each. Substantial structural response data were obtained with minimal impact on normal lock operation. Based on experimental strain data obtained during the field tests, it was determined that the analytical (finite element) models provided reasonably accurate predictions of the general behavior. Experimental and analytical data comparisons provided quantitative information on lift gate behavior and loading conditions. Through data comparisons for the Locks 27 lift gate, it was concluded that: (1) one of the seals did not exist; (2) an unknown amount of frictional resistance exists between the bottom sill and bottom of the leaf; and (3) for this case, a dynamic load model is most appropriate for simulation of hydrostatic head differential loading. Through the Locks and Dam 26 study, it was verified that the downstream bracing members are primarily affected by vertical loading, and a probable cause for cracking of downstream bracing members was obtained.