This document discusses permeation grouting for remediation of dam cores. Permeation grouting involves injecting thin chemical grouts into soil to stabilize it and make it impermeable. It is done using chemical grouts and is used to stabilize soil before excavation. The document provides details on different types of grouting including intrusion, compaction, permeation, jet, and electro grouting. It also discusses grouting materials and advantages and disadvantages of grouting.