Feasibility of retrofitting existing miter-type lock gates with discontinuous contact blocks

Abstract

ABSTRACTThe US inland navigation system facilitates the transportation of billions of dollars of goods annually, with lock gates being a major component of the system. Miter-type gates are the most common found in the US and are typically designed to bear continuously against the lock chamber wall along the height of the gate in the region known as the quoin. To aid continuous contact along the quoin, adjustable contact blocks are installed. Currently, contact blocks are large, continuous pieces of steel, making installation and adjustment difficult and expensive. Furthermore, the entire quoin block needs to be replaced if only a small portion is damaged. Initial investigations revealed that the reaction distribution in the quoin with a continuous contact block is likely not distributed uniformly as assumed in design, raising the question of the necessity of a continuous contact block system. Thus, this study investigates using smaller, intermittent quoin blocks as a retrofit option on existing miter gates. Numerical models of several lock gates are utilized, and the stress fields are compared between gates utilizing continuous and discontinuous contact blocks. It is demonstrated that discontinuous quoin blocks are a feasible retrofit option, albeit with a potential need for additional retrofit requirements.