Deformation and Subsidence prediction on Surface of Yuzhou mined-out areas along Middle Route Project of South-to-North Water Diversion, China

Abstract

AbstractThe Middle Route of the South-to-North Water Diversion Project crosses the coal mined-out area in Yuzhou city. There are 4 mined-out areas along Yuzhou section of the water diversion project. The collapse, fracture and deformation of overlying rock mass occurred due to strata loss and stress field change, which then resulted in the subsidence, collapse fissures on the ground. The deformation of the upper rock mass is characterized by “three-zone”: caving zone, fault zone, and bend zone. Thus, it is very important to predict the surface subsidence of the mined-out areas. Highly precise deformation observation network were set along the channel. The monitoring data show that the surface tilt, curvature and horizontal deformation of the mined-out areas were less than critical values. However, the forecast and monitoring values are relatively larger in Guocun and Xinfeng mined-out areas due to large mining range and the possible location of two mined-out areas in the affected region. Therefore, the monitoring should focus on the two mined-out areas.