What is the term used when there is upward water flow into the bottom of an excavation?

The term that describes the upward water flow into the bottom of an excavation is known as "boiling." This phenomenon occurs when water flows upward through sediment or soil, which can create a condition where the soil loses its strength and begins to behave like a fluid. This can compromise the stability of the excavation site, potentially leading to dangerous conditions like flooding or collapse. Understanding this term is crucial for contractors and engineers to ensure they take appropriate measures for drainage and excavation safety.

In contrast, raveling refers to the gradual disintegration of materials in a slope or wall that can lead to erosion, while heaving involves upward movement of soil due to freeze-thaw cycles or other pressure changes. Subsidence is the settling or sinking of the ground surface, typically due to the removal of underground support or excessive weight above, rather than water flow into an excavation. Each of these terms describes different physical processes and understanding their distinct meanings is important in the context of construction and soil behavior.