Flexible approach walls are being considered for retrofits, replacements, or upgrades to Corps lock structures that have exceeded their economic lifetime. This report discusses a new engineering software tool to be used in the design or evaluation of flexible approach walls founded on clustered pile groups and subjected to barge train impact events.This software tool, Impact_Deck, is used to perform a dynamic, time-domain analysis of three different types of pile-founded flexible approach walls: an impact deck, an alternative flexible approach wall, and a guard wall. Dynamic loading is performed using impact-force time histories (Ebeling et al. 2010). This report covers the numerical methods used to create this tool, a discussion of the graphical user interface for the tool, and an analysis of results for the three wall systems.