| Summary: | 碩士 === 國立交通大學 === 土木工程系所 === 107 === To prevent the disaster in mountain, we must consider the shear wave velocity of soil and the thickness of the collapse layer. Using the non-destructive passive surface wave seismic method, the formation profile can be measured economically and widely. It is different from basic assumptions, when the passive surface wave seismic method is applied to the mountainous area, so it is necessary to discuss the effect of the source location and the slope conditions. In this study, three-dimensional numerical models were utilized. The transfer behavior of surface wave is simulated by spectral element method in a horizontal stratum by non-uniform sources, in sloping stratum by uniform sources and in hilly topography, and to explore its impact on the analysis results and further reduce the impact or avoid the impact.
The research results show that in the case of passive source with main source direction, the impact on Spatial autocorrelation method(SPAC) is small, but there is offset on dispersion curve between Multichannel analysis of passive surface(MAPS) and theoretical solution. It is suggested to use active surface wave seismic method to obtain phase velocity of a certain frequency segment. Used as a reference for MAPS correction. The uniform source of the inclined layer will cause non-uniform sources, the impact on the SPAC method is not so obvious. And the dispersion curve by MAPS mothed got offset, and it can still be corrected by the active surface wave seismic method. In mesoscale slopes, the slope and source location will affect the analysis results. The steeper the slope or the source and the stations are on different sides of the hill, the interpretation of the dispersion curve is more difficult, but the passive concept-interferometry can improve the applicability of surface wave dispersion analysis in mesoscale hillsides.
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