ARRAY MICROTREMOR SURVEY AND ITS APPLICATION TO CIVIL ENGINEERING
微动勘探技术及其在土木工程中的应用

The Array Microtremor Survey(AMS) is briefly presented and its application is discussed to geotechnical investigation for civil engineering based on field experiment data. For this method, first, microtremors are observed simultaneously by a number of seismometers deployed in an area on the ground surface, then, phase velocity of surface wave is calculated from the observed microtremors using stationary stochastic process theory, finally, the subsurface shear wave velocity structure is estimated by phase velocity inversion. To study the application of this method to shallow geotechnical investigation for civil engineering, a series of field experiments and theoretical analyses are made. The result of the study shows that shear wave velocity structure given by AMS agrees well with the result of the conventional P-S log method in general. Though the AMS is slightly inferior to the PS log in resolution, it gives good accuracy for thick layers. Unlike the P-S log method, the AMS does not need to drill a borehole, thus it can save both money and time and be gentle to the environment. Furthermore, since the traffic vibration is no more a noise, but it provides a source for high frequency signal, the AMS method can be considered as an inexpensive, fast and gentle method for geotechnical investigation in urban area.