Interpretation Method of Transient Electromagnetic Data in Tunnel Based on Variable Dimension Bayesian

Abstract

The invention relates to a method for interpreting transient electromagnetic data of tunnels based on variable-dimensional Bayesian. The method includes using a transient electromagnetic instrument, placing it at the face of the tunnel for detection, and obtaining observation data of the water-bearing structure of the face of the tunnel; Perform transient electromagnetic data preprocessing on the obtained observation data; use the variable-dimensional Bayesian algorithm to invert the preprocessed data, obtain all possible geological resistivity distributions and layer interface position information in front of the tunnel face, and extract the largest Probabilistically corresponding resistivity and layer interface position distribution information; according to the maximum probability geological resistivity distribution and layer interface position information, the abnormal situation of the water-bearing structure in front of the tunnel face is given, and the uncertainty analysis is carried out to obtain an accurate water-bearing structure distribution range. While inverting and interpreting the location of low-resistance anomalies (water-bearing structures) in front of the tunnel face, the uncertainty analysis of the inversion results is given, and finally the distribution range of resistivity is given, which provides early warning guidance for the safe development of tunnel engineering.

Description

technical field [0001] The invention relates to the research field of geophysical signal processing and analysis technology, in particular to a tunnel transient electromagnetic data interpretation method based on variable-dimensional Bayesian. Background technique [0002] During the construction process of the tunnel project, it is often faced with geological disasters such as underground water inrush and landslides. These disasters will not only cause construction delays, but also cause tunnel collapse to threaten the lives of construction workers. Due to its convenient detection and sensitive response to groundwater, the transient electromagnetic method has been more and more used in the advanced geological prediction of tunnel disasters in recent years. [0003] The correct interpretation of tunnel transient electromagnetic data is very important, which determines the correct judgment of the construction personnel on the geological situation ahead. The inversion of trans...

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Problems solved by technology

[0003] The correct interpretation of tunnel transient electromagnetic data is very important, which determines the correct judgment of the construction personnel on the geological situation ahead. The inversion of transient electromagnetic method is a nonlinear problem, and its solution is usually not unique, that is, for the underground model parameters There are multiple or infinite geoelectric parameter models that can match the measured data, while conventional transient electromagnetic inversion methods can only give a single optimal solution, and cannot obtain the uncertainty of the current inversion model parameters information

Generally speaking, estimating parameter uncertainty or model non-uniqueness is as important as estimating the parameter value itself, especially for TEM, this defect will pose a greater security threat

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