A new approach for forecasting the appearance of sinkholes near the Jinshazhou tunnel

摘要

The paper deals with a frequent and known problem of suffusion type of sinkhole formation in soil, due to water level oscillations above karstified bedrock. The authors measured groundwater pressure oscillations caused by pumping groundwater from the excavated tunnel to determine the reliable indicators for prediction of sudden soil collapse based on risk assessment. The statistical analysis was performed to determine suspicious values, which reliably predict the soil collapse. The results of analysis of monitored values indicate very good time correlation coefficients with the failures. The work comprises the following main parts: (1) survey of the geologic environment; (2) monitoring of hydrodynamic conditions; and (3) acquisition of a forecasting criterion based on the statistical analysis of anomalous monitoring data. From this research, it might be concluded that the appearance time of sinkholes and the abnormal values were strongly linearly dependent with a correlation coefficient of over 99 %. This conclusion will be a contribution to estimate the risk of karst collapse in a similar environment.