The problem of the ground collapses is common for the regions affected by the underground mining, as well as for the areas prone to the sinkholes of natural or human genesis. This paper describes the case of the ground surface collapse occurred in 2013 above the active Saranovsky chromite ore underground mine that has been operating for over eighty years. The results of pre- and post-failure high-precision levelling of the ground surface are presented. The monitoring network includes more than one hundred surveying points covering the area of about 1 km² and since 2006 geodetic measurements have been conducted on an annual basis. The analysis pointed to a complex deformation process, manifested in the cyclic succession of subsidence and uplift of the surface. A local zone of continuous surface subsidence was identified immediately above the site of the future collapse. The deformations started several years before the failure. The extent of the subsiding area increased gradually, approximately approaching the size of the collapse (over 7000 m²). During the three-year period preceding the collapse, this area expanded by over a factor of ten, and the cumulated subsidence rate doubled. However, since the monitoring points located within the sinkhole area were lost, the data of the geodetic campaign carried out before the collapse were insufficient to estimate the value of the subsidence preceding the failure. Our results demonstrate, that in hard rocks mining-induced deformations can develop in utterly localized way. The progression of the subsidence was detected generally within the area of the future failure and did not extend significantly beyond its contours. In this paper, we highlight the importance of further development of the monitoring techniques and justification of hazardous deformation criteria for the early warning systems in mining regions and sinkhole-prone areas.

地面塌陷的问题在受地下采矿影响的地区以及易于发生自然或人为起源的地区都是常见的。本文描述了2013年活跃的Saranovsky铬铁矿地下矿井上方地面塌陷的情况，该矿井已有80多年的历史了。给出了故障前后地面高精度找平的结果。监控网络包括一百多个测量点，覆盖面积约1 km ²自2006年以来，每年都进行大地测量。分析指出了复杂的变形过程，表现为地表沉陷和隆起的周期性演替。在将来坍塌的位置上方立即确定了一个连续地面沉降的局部区域。变形是在故障发生前的几年开始的。沉降区域的范围逐渐增加，大约接近坍塌的大小（超过7000 m ²）。在倒塌之前的三年中，该区域扩大了十倍之多，累积沉降率翻了一番。但是，由于位于下沉孔区域内的监测点丢失了，因此在坍塌之前进行的大地运动的数据不足以估计破坏前的沉降值。我们的结果表明，在坚硬的岩石中，采矿诱发的变形可以完全局限性地发展。通常在将来的失效区域内检测到沉降的发展，并且沉降没有明显超出其轮廓。在本文中，我们强调了进一步开发监测技术以及为矿区和易陷井区域的预警系统确定危险变形标准的重要性。