A demonstration of observation array configuration for micro-tremors by F-K spectrum method

Abstract:

To ensure the rationality of array design and save the cost of observation,the conventional observation array was analyzed,and a rational configuration for micro-tremors was demonstrated in this paper.The frequency-wave number spectrum (F-K spectrum) from records at arrays with different shapes and survey point numbers in a simulated sine decaying wave field was investigated,in which the circle array cross-shaped array and rhombus-shaped array were included.The acceptability of the array configuration was validated by the criterion whether there is one and only one extreme on the F-K spectrum,and whether the direction of the vector is consistent with the direction of the incident wave.The result shows that using the rhombus-shaped array can obtain more precise result with few observation points,and it is the best configuration to estimate the structure of shear wave velocity of site by the micro-tremors array observation method.