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Micropiles are the best deep foundation system in challenging karst geology. In Subsurface Construction's service location, karst is discovered in the hills of Virginia and eastern Tennessee. Since karst consists of layers of hard rock and soft dirt https://www.scribd.com/document/673127694/224733Sorts-Of-Micropile-Advantages-Downsides-Of-Micropiles or voids, micropiles can be cased with the soft areas to experienced rock.