## 4 Applications to Field Data
### Result Analysis  
The He'an Line is 750 m long, with 151 exploration points. The pseudo two-dimensional profile of the apparent S-wave velocity is obtained through an inversion of the dispersion curve of each exploration point, as shown in Figure 8.  
It can be seen from the inversion profile that the effective inversion depth is about 75 m. The apparent S-wave velocity of the profile is evenly distributed, horizontally continuous, and longitudinally with obvious increase and stratification. Generally, it can be divided into four layers. The apparent S-wave velocity interfaces are 200 m/s, 300 m/s, and 500 m/s, respectively. Two boreholes, zk43 and zk47, are distributed near the survey line mileage of 155 m and 545 m. According to the borehole data, the geological significance of the profile is as follows: the surface layer (1 in Figure 8) is silty clay (plastic) and silty fine sand (slightly dense), the apparent S-wave velocity is less than 200 m/s, and the bottom depth varies between 19.2-26.2 m; the second layer (2 in Figure 8) is silty fine sand (moderately dense) and medium sand (dense), the apparent S-wave velocity range is 200-300 m/s, and the bottom depth varies between 43.2-49.6 m; the third layer (3 in Figure 8) is sand mixed with pebbles and strongly-weathered conglomerate, the apparent S-wave velocity range is 300-500 m/s, and the bottom depth varies between 53.5-58.5 m; and the bottom layer (4 in Figure 8) is moderately-weathered conglomerate, and the apparent S-wave velocity is greater than 500 m/s.  
The microtremor inversion data reveal that the deposit of each layer is relatively stable, the shear-wave velocity structure gradually increases, and the overburden thickness varies within the range of 53.5-58.5 m.  
Figure 8: Microtremor inversion result of the He’an line in area I.  
The Shamao Line is 800 m long, with 161 exploration points. The pseudo two-dimensional profile of the apparent S-wave velocity is shown in Figure 9.  
It can be seen from the inversion profile that the effective inversion depth is about 120 m. The apparent S-wave velocity of the profile is relatively evenly distributed, horizontally continuous, and longitudinally with obvious stratification. Generally, it can be divided into six layers, of which there is a low-velocity weak interlayer near the depth of about 75 m. Three boreholes, zk10, zk11, and zk12, are distributed near the survey line mileage of 160 m, 470 m, and 750 m. According to the borehole data, the geological significance of the profile is as follows: the surface layer (1 in Figure 9) is silty clay (soft plastic and plastic), the apparent S-wave velocity is less than 200 m/s, and the bottom depth varies between 27.9-33.7 m; the second layer (2 in Figure 9) is silty fine sand (slightly-moderately dense), the apparent S-wave velocity range is 300-450 m/s, and the bottom depth varies between 38.3-45.9 m; the third layer (3 in Figure 9) is medium-coarse sand mixed with gravel (medium-dense), the apparent S-wave velocity range is 300-500 m/s, and the bottom depth varies between 59.8-67.7 m; the fourth layer (4 in Figure 9) is a low-velocity soft layer of silt mixed with silty clay (plastic), the apparent S-wave velocity is less than 300 m/s, and the layer thickness is about 17.5-23.0 m; the fifth layer(5 in Figure 9) is strongly-weathered argillaceous siltstone, the apparent S-wave velocity range is 300-500 m/s, and the bottom depth varies between 94.2-107.5 m and gradually becomes deeper along the SE direction; and the bottom layer (6 in Figure 9) is moderately-weathered argillaceous siltstone, and the apparent S-wave velocity is greater than 500 m/s.  
The microtremor inversion data reveal that the bedrock surface gradually deepens along the SE direction, the deepest part of the profile is about 107.6 m, and there is a low-velocity weak layer (4 in Figure 9) on it, with a thickness of about 17.5-23.0 m. The deposit of the upper layers 1, 2, and 3 is relatively stable, and the bottom depth changes little.