MANAGEMENT SOFTWARE FOR PROTECTION OF THE GREAT LAKES COASTAL NAVIGATION AREAS

Protecting harbors or navigable areas requires evaluating maritime structures such as armor stones. Armor rocks are impacted by the natural deteriorating elements such as seasonal weather, and repeated cycles of temperature, flowing water, wetting and drying, wave action, and freeze and thaw cycles. The design process for the determination of armor stone sizes is complex and various factors must be considered to fully understand how the design parameters have effect on stone performance. The main objective of this study was to evaluate and quantify major factors affecting the armor stone durability. The effects of scaling on the test results of various samples of rock types used in Great Lakes coastal projects have been investigated. Field monitoring and laboratory testing have been conducted to evaluate the performance of stone subjected to both freezing and thawing and wetting and drying, and to quantify the combined effects of environmental stresses on armor stone. In addition, long-term performance or deterioration of armor stones have been quantitatively monitored and characterized by the changes in dimensions measured. We have developed stone deterioration software (ARMOR), which integrates field observations with numerical tools to provide an assessment of the local freeze-thaw and wet-dry on the stones. The ARMOR software has several numerical models, which can predict degradation of Armor Stone as rocks are impacted by the natural elements. The software includes a statistical technique (homogeneity index) to characterize rock heterogeneity. Two new numerical approaches have been developed to calculate freeze thaw cycles using long-term site weather data. The software also provides a model to estimate armor weight, minimum crest width, armor thickness, and the number of armor units per unit of area. The calculation uses varying values for the seaward slope and wave height by application of the Hudson formula. The degradation model relates the laboratory test results to the modification of the mass distribution and reduction at the project site. Innovative technologies such as geophysical techniques in stone selection and stonecutting (water saw) are examined for the field applications. This paper describes the latest research developments that improve our understanding of environmental impacts on armor stones in coastal areas with reference to breakage and integrity.