Abstract:Research purposes:In the audio magnetotelluric exploration of large railway tunnel, it is one of technical problems that how to objectively recognize and deal with the false electrical abnormality caused by static shift. Considering the response characteristics that two-dimensional magnetotelluric impedance phase is not affected by the static shift , we put forward an estimation method of static shift based on impedance phase,hoping that this can more objectively estimate the static shift parameter. On this basis, static shift parameter is used in the two dimensional inversion,in order to ensure that the electrical structure of the inversion model is more reasonable.
Research conclusions: Compared with the other static shift correction method,the static shift parameter that is estimated based on impedance phase can be close to the true value,artificial arbitrariness is smaller. Use shift parameter for translation of anomaly measured curve,according to the one-dimensional inversion curve results after the translation construct a reasonable initial model for the two-dimensional inversion. On the basis, we do two-dimensional inversion for the original data,which not only can effectively eliminate the influence of static shift on the deep structure of inversion model, but also can get the right shallow electrical structure in the inversion. The model calculation and engineering cases show that the estimation algorithm of the static shift and its application method in the inversion,can effectively removal the two-dimensional magnetotelluric static shift.
王绪本,周军,李海蓉,李坚,苟定才. 二维大地电磁静位移估算及其在隧道勘探中的应用[J]. 铁道工程学报, 2014, 31(8): 20-26.
WANG Xu-ben,ZHOU Jun,LI Hai-rong,LI Jian,GOU Ding-cai. The Estimation of Two Dimensional Magnetotelluric Static Shift and Its Application in the Tunnel Exploration. Journal of Railway Engineering Society, 2014, 31(8): 20-26.
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