Replacement-Lock and Dam No. 26: Condition of Existing Structure

The physical condition of the structure described in this paper was part of a comprehensive study undertaken by the St. Louis District, Corps of Engineers to determine the adequacy of an existing navigation structure to provide reliable facilities for future navigation. It presents and evaluates investigative studies including construction problems, problem events after construction, field inspections including concrete coring and testing, lateral movements, hydrographic surveys, and foundation investigations on the structure after 30 yrs of performance. Data collected are evaluated and analyzed with a view towards determining an explanation for some of the problems which have befallen the structure. Analyses include physical and ultrasonic testing of concrete, Hrennikoff analysis to predict observed movements, and foundation dye tests. Many photographs are presented illustrating the deterioration of the structure. The paper concludes with recommendations for rehabilitation measures to be taken during a 10 year interim period prior to construction of new facilities at another location.