微动勘查方法在煤矿采区勘探中的应用研究

The conventional microtremor survey is based on the single point of exploration, which includes collecting field data，estimating the phase velocity, investing the dispersion curve and obtaining the S–wave velocity structure. In the case of large-scale exploration, and when making the two-dimensional velocity section, the inversion is quite time-consuming, laborious and its precision depends on the subjective interpretation, which makes the results differently from person to person. In fact，we do not need the S-wave velocity values but only need the relative variation of velocity. For these reasons, this paper is desired to calculate the apparent S-wave velocity (Vx) to replace the S-wave velocity inversion and to obtain the relative variation of the S-wave velocity. Using this method, we can decrease the analysts’ effect, shorten the data processing time and improve work efficiency. The apparent S-wave velocity is a variable of the surface wave property, which can clearly reflect the downcast columns, mined-out areas and other unusual geological bodies. In this paper, Matlab is used to establish the three-dimensional data volume of the apparent S-wave velocity, from which we can get any apparent S-wave velocity section we need. Through the application case, the designed method is proved to be reliable and effective. The downcast columns, mined-out areas and other unusual geological bodies can be clearly showed in the apparent S-wave velocity section. And from the contour of the apparent S-wave velocity, the interface shape of the major target layers can be controlled basically.