Site 2D Velocity Structure Imaged by Microtremors Method

Abstract

In this paper, a two-step space prediction approach is developed to image site 2D velocity structures. Firstly the average Vs of each layer are fixed, the interfaces between each two soils layers are predicted by the interpolation method of bi-harmonic Green function as spline in tension, to keep soil interfaces varying smoothly in space. Furthermore, a method to determine tension coefficient is proposed based on microtremor H/V method, which makes most use of H/V information and avoids choosing the tension coefficient at will. Secondly, the variance essence of the Vs structure as a regional variable is deeply excavated by Kriging method and its structural characteristic is taken into account. The spatial successive distribution of the Vs structure between soil interfaces is simulated by high precision space extrapolation and prediction, and finally the detailed 2D model is constructed. The two-step space prediction approach describes the characteristic of Vs structure as a regional variable from the sparsely and non-uniformly distributed microtremors data. Obviously, it also can easily make good use of the other exploration data.