High-Resolution Simulation of Point Bar Structures Associated with Paleochannel Evolution with GPR

摘要

The new wave of urban underground space development in the world, especially inside China, stimulates the need for precisely locating the position of paleo-channels due to their potential effects on stability of underground structures from the engineering point of view, and their potential cultural heritage values from the archaeology point of view. Paleo-channel structures are traditionally investigated in petroleum exploration industry driven for the purpose of secondary discovery of hydrocarbon residuals in the developed reservoir. As an evidence and record of cultural heritage of a city paleo-channel structures and their evolution are of important significance to the comprehensive design and usage of underground space as a resource. Using the numerical simulation technique we conducted scenario research to look into the possibility of detection the sand bar structures that directly record the evolution of the meandering of a river system in history. Besides the traditional three-dimensional (3D) surface GPR survey to get the horizontal slices at different depths, we are also particularly interested in examination of the sand bar structure from side views, in view of the availability of side walls in underground structures that enable us to conduct side-view GPR profiles. With the numerical simulation by the pseudo-spectral time domain technique, we generated an image cube and discussed the possibility of applying GPR from all available sides to re-construct a high-resolution paleo-channel structure.