Analysis of residual subsidence movements in the UK coalfields

Abstract

Abstract The importance of residual subsidence in the study of ground movement due to mining is discussed and previous research results are briefly reviewed. On the basis of ten cases investigated within the UK coalfields, the difference between residual subsidence characteristics along longitudinal and transverse lines is studied. Particular attention is paid to the four key positions along the subsidence profile, i.e. the subsidence limit position, the half-subsidence position, the rib-side position and the central position. A case example associated with mining an inclined seam is investigated in detail, showing that different residual subsidence characteristics appear due to mining an inclined seam as opposed to a level seam. Additionally, a prediction model is presented and applied to determine the duration of residual subsidence. The model theoretically indicates the main factors controlling the period of residual subsidence. Finally, an empirical equation, based on data collected within the UK coalfields, for estimating the duration of residual subsidence is put forward with consideration of both depth and geological factors. This is believed to be an important tool for civil engineers to calculate the time span after which no precautions need be taken to protect surface buildings from further damage due to residual subsidence movements.