Research on the application of microtremor survey in the investigation of goaf area of Tianshun Mine in Xinjiang

There are a large number of old kiln hollowing zones since the 1950s in Tianshun mine in Xinjiang, which pose a serious threat to mine safety and production. Although traditional geophysical exploration methods have been used to detect these goafs, their accuracy and depth resolution remain insufficient. Microtremor survey, as a novel geophysical technique, offers advantages such as high precision, deep detection capability, and operational simplicity. This study systematically investigated the goafs in the Tianshun Coal Mine using microtremor survey technology. A three-component nodal digital microtremor instrument was deployed to collect data from 1,349 physical points across a 1.21 km² survey area. Statistical methods were employed to determine the threshold for low-velocity anomalies, and spatial autocorrelation analysis was applied to invert dispersion curves. The results reveal 11 typical low-velocity anomaly zones at depths of 90–210 m, which show significant correlations with goafs formed by the mining of the Upper 1, Upper 2, Middle 2, and Middle 4 coal seams. The study also demonstrates that these low-velocity anomalies exhibit a vertically stacked and laterally continuous distribution pattern, confirming the technical superiority of microtremor surveys in detecting complex goaf areas. This research provides a scientific basis for safe production at the Tianshun Coal Mine and serves as a reference for goaf detection in similar mining environments.