Subsidence measurements in roads and implementation in land use plan optimisation in areas affected by deep coal mining

Abstract

This paper presents a study of 12-year monitoring of ground subsidence along a selected road affected by subsidences trough induced by underground black coal mining in the largest mining district in the Czech Republic. The major scientific contribution of this study is that it suggests a new methodology that involves independent observation of a subsidence trough in the linear direction (a road), permitting determination of the ground deformation parameters and related building site categories. In areas affected by deep coal mining, it is vital to update the current status of the building site categories, which represent the zones of potential hazard posed to the existing structures or future development. It is possible to identify the actual conditions in the localities using systematical measurements along roads which are in any case required for periodical maintenance in areas of underground mining. Prognoses may be subsequently optimised in this way and investors, property owners and mining companies may benefit through saving on costs associated with subsidence damage. In fact, there are two eventualities, i. e., the conditions either improve or deteriorate. The latter occurred in the case of the study area. In the beginning, the majority of the study area, i. e., 91 %, belonged to the most suitable category of building sites, which means that development was possible without any restrictions. At the end of the observation, the measurements showed a prominent fall of the subsidence trough, and as much as 19 % of the area fell into the least suitable categories I or II, where development is prohibited. The publication recommends that mining companies use road monitoring as an independent monitoring tool to determine the hazard in regions affected by deep coal mining. It is possible to conveniently verify the prognostic maps in land use planning in this way.