settlement

…in a gradual manner, called settlement. Subsidence involves a roof collapse or breakdown of a subsurface cavity such as a cave. Extensive subsidence is evident in areas where coal, salt, and metalliferous ores are mined. Marine erosion sometimes causes the roof collapse of sea caves. Regions of karst topography will…

…the need to avoid intolerable settlement damage to adjoining buildings. While this is rarely a problem in the case of modern skyscrapers, which usually have foundations extending to rock and deep basements often extending below the tunnel, it can be a decisive consideration in the presence of moderate-height buildings, whose…