With the expedition for the development and utilization of urban underground space, pre-planning survey has entered a new stage. The seismic method is a non-destructive, efficient and convenient exploration method. The microtremor method has certain advantages for delineating stratigraphic structures.

The survey project adopts a linear array fashion to arrange the seismic stations, and using the adjacent one spacing correlation processing, a better velocity-depth curve can be obtained through inversion that is in high agreement with the ‘ground truth’ provided by borehole drilling information. Compared with the circular array, this method is more practical in urban environment and can the full advantage of the node seismic equipment.

The microtremor exploration depth is related to the array layout. For this example, the minimum spacing of the array is 5 meters, and use 7 instruments to form one array. The results show that it is capable to delineate layer structures for the depth range of 0-60 meters. The results of the stratigraphy are confirmed by the borehole drilling information.