INVESTIGATION OF GROUND COLLAPSES OVER A SHALLOW ABANDONED MINE TO DETERMINE THE GEOTECHNICAL CONDITIONS OF INDIVIDUAL CONSTRUCTION

Abstract

The relevance of the study is caused by the need to construct buildings and structures over old abandoned mines. Construction is associated with the danger of failure of the earth's surface and the destruction of buildings. This problem is widespread all over the world. The aim of the research is to determine the risk of building a small plot of land located above an old gold mine and the parameters of likely hazardous processes; to predict potential damage. Methods: analysis of archival geological documents abandoned mines, reconstruction and two-dimensional modeling of mine workings under the studied area, on-site visual examination of the surface analysis of optical satellite imagery database analysis of the collapse surface geophysical sensing of the mountain massif with the surface. Results. Using two-dimensional modeling, it was found that only one of two granitoid dikes developed within the boundaries of the study, is dangerous, since the other, according to geological conditions, is the main body lying outside the study. This facilitates the conditions for construction. Dangerous processes from the drift and orta dike, which falls on the site, can only be in the westernmost part with a width of 5 m. It is established that since 1957, no surface failures have been observed in this place, and the dangerous phenomena registered in the vicinity are the subsidence of the soil with a diameter of 1–2 m and a depth of 0,5 m. In the southwestern corner of the site above ort, a 3-meter-deep zone filled with coarse and fine-grained material was detected, which is most likely a trace of its collapse. Indicators that can be identified as voids or a disintegrated array are not detected by two methods. Conclusions. The authors have made forecast of the parameters of an old mine harmful effect on stability of the surface. The research established that a cottage can be built on this site above an abandoned mine without the risk of permanent damage during operation. The land is safe for construction and living. The geometric parameters of the probable harmful effect of underground mining and the frequency of manifestations are determined. Geotechnical measures to minimize the possible harmful effects of an abandoned mine are proposed.

Keywords

• abandoned mine
• old mine workings
• ground collapse
• subsidence
• construction
• safety
• forecast and assessment
• geotechnical measures
• building placement conditions