Comprehensive Ahead Prospecting of Tunnels in Severely Weathered Rock Mass Environments with High Water Inrush Risk: A Case Study in Shaanxi Province

Abstract

The ahead geological prospecting of severely weathered surrounding rock in a tunnel is challenging due to complex geological conditions. Hence, the best approach is to use a variety of geophysical exploration methods. In this study, we have applied seismic, electrical resistivity (ER), and transient electromagnetic (TEM) methodologies for ahead prospecting of the highly weathered and complex surrounding rock at the diversion tunnel of the Hongyan River to Stone River Water Transfer Project in Shaanxi Province, China. The seismic method was employed to detect structural information for an area of 100 m from the front of the tunnel, the TEM method was used to obtain the resistivity information within 60 m, and the ER method was conducted to obtain detailed resistivity information over a range of 30 m. The integrated results generated a comprehensive interpretation of the geological body located within 100 m of the front of the tunnel. We divided this geological area into intact, severely weathered, and slightly weathered sections. Information on the water content of each section was also produced. The results of subsequent excavations are consistent with our results, proving the effectiveness and feasibility of a comprehensive approach for analyzing highly weathered and complex surrounding rock.

Water Inrush Risk Assessment Based on AHP and Advance Forecast Approach: A Case Study in the Micangshan Tunnel

“…Using only a single advanced prediction method, it is difficult to accurately detect the geological conditions in front of the tunnel. In particular, under the complex geological and hydrogeological conditions such as those in the Micangshan tunnel, it is more important to determine a scientific, effective, and accurate advance geological prediction method [44,45].…”

Data acquisition-interpretation-aggregation for dynamic design of rock tunnel support

“…After the detection of well-developed structure planes, such as faults and folds, along with the abundant water, steel frame, steel meshes, and shotcrete thickness were optimized accordingly. Bu et al [76] and Nie et al [88] combined GPR and TEM to detect the position and spatial distribution pattern of water-rich areas. These results provide an effective reference for the implementation of dynamic design and construction schemes.…”

Mine Water Inrush Risk Assessment Evaluation Based on the GIS and Combination Weight-Cloud Model: A Case Study

“…Qiu et al adopted the fuzzy AHP based on geology, hydrogeology, floor permeability, and other factors to construct the water inrush index of coal seam floor. Similar studies also include the studies by Nie et al and Shi et al These methods have the limitation of randomness and fuzziness due to their strong subjectivity, so the evaluation results are often inaccurate . The combination weighting method based on game theory and the cloud model can solve the above limitations.…”

“…Hu et al 16 obtained the weights of the evaluation factors through AHP and the entropy weight method (EWM) and further determined water inrush risk zonation using the GIS technology. Qiu et al 17 by Nie et al 18 and Shi et al 19 These methods have the limitation of randomness and fuzziness due to their strong subjectivity, so the evaluation results are often inaccurate. 20 The combination weighting method based on game theory 21 and the cloud model can solve the above limitations.…”