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The3-D Numerical Implementation Of The Whole Tunnel Space With Tem

Posted on:2015-02-02Degree:MasterType:Thesis
Country:ChinaCandidate:Z Y ZhouFull Text:PDF
GTID:2250330428976245Subject:Bridge and tunnel project
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In recent years, as the country to input to the transport infrastructure, many grew up one after another to build a tunnel.Grew up in these tunnels during the construction of a number of tunnel construction accidents, many of these accidents are caused due to the groundwater, traditional geological prediction method is limited due to its own characteristics, poor detection of the effect on the water, so an urgent need to find a water exploration methods. After Engineering Practice has proved that the transient electromagnetic method can be more accurate detection of groundwater. However, when applied in a tunnel whole space transient electromagnetic method is a problem the whole space, the tunnel the whole space transient electromagnetic method is also a lack of systematic research, especially close relationship with the project are three-dimensional inversion problem. This thesis is just under this background.Nowadays, three-dimensional transient electromagnetic forward, inverse problem is a hot issue research. Tunnel whole space three-dimensional inversion problem is still in the exploratory stage.Based on the research thesis on the half-space problem, combined with the characteristics of the whole space of the tunnel derived three-dimensional time-domain iterative differential equations under consideration from the numerical count introduces numerical dispersion stability under time domain numerical stability problems, and get the value stable condition.Thesis completed the following aspects of the work:1. When dealing with boundary conditions, considering the characteristics of the whole space of the tunnel, introduced CPML boundary conditions. The boundary conditions can be an excellent simulation of electromagnetic problems in border issues, reducing refraction reflection.2. In studying the three-dimensional forward problem, in order to ensure a reasonable model to study the problem by tunneling length value; influence of different sizes of the electromagnetic response of conductive body; different conductive body such as electromagnetic response.These results can provide a reference for the establishment of a reasonable model.3. In examining the tunnel the whole space inversion, calculated for the three-dimensional inversion of large, time-consuming characteristics, using an improved feature inversion, effectively reduces the computation time and improve efficiency.4. Made more feasible inversion path, making the inversion can be carried out smoothly in meeting conditions under some restrictions, and proposed related approaches morbid control matrix inversion.
Keywords/Search Tags:The whole space, Transient electromagnetic method, A three-dimensionalfinite difference, The three dimensional forward, The three dimensional inversion
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