Study on prediction method of surface movement duration in thick alluvial mining area

The surface movement duration is a key index of surface subsidence stability，it is very important to accurately predict the time for the stability evaluation of surface and ground facilities. Due to the particularity of thick alluvium and the limited consideration of influencing factors by existing methods，the prediction error of existing methods in thick alluvial mining areas is too large. In order to solve this problem，the influencing factors of surface movement time，such as mining depth，mining thickness，alluvium thickness and advancing speed arecomprehensively considered. Based on the measured data of 15 working faces in Panxie New Area of Huainan，the relationship between the influencing factors and the duration of surface movement was analyzed，and a new calculation model of surface movement duration in thick alluvium mining area was established，and then the accuracy of the calculation model was analyzed，and the SBAS-InSAR technology was used to verify the actual measurement. 〖JP2〗The results show that:the duration of surface movement is positively correlated with mining thickness and mining depth，and negatively correlated with advancing speed and alluvium thickness; the accuracy of the new model is improved by 86% and 44% by using the data that involved in and did not involve in the modeling respectively. The relative error between the calculation results of the new model and the Sentinel-1 data calculation results is at least 7.2%，which confirms the correctness of the calculation method again. Compared with the traditional empirical formula，the new formula in this paper has stronger applicability and higher accuracy，which can provide technical support for related work such as foundation stability evaluation in thick alluvium mining area.