Case study subsidence

Subsidence prediction is highly developed in Europe where there are comparatively uniform mining conditions and a long history of field measurements. Much of this mining has been carried out beneath crowded urban and industrial areas where accurate predictions have facilitated use of the surface and re­ duced undesirable impacts.

In order to develop broadly applicable subsidence prediction methods and models for the United States, more in­ formation is needed on magnitude and timing of ground move­ ments and geologic properties. INTRODUCTION The worldwide need for energy resources re­ quires increased production of coal and other fuels.

Subsidence is a time-dependent process, either natural or man induced, in which there is a lower­ ing of the ground surface in response to the re­ moval of gas, liquid, or solid matter. Deformation of the rock mass may be by either elastic, plastic, or brittle processes or by any combination of these processes.

The impacts of subsidence are potentially severe in terms of damage to surface utility lines and struc­ tures, changes in surface-water and ground-water conditions, and effects on vegetation and animals.