# Investigation on Vibration Influence Law of Double-Shield TBM Tunnel Construction
## 5 Research on Vibration Influence Range of Double-Shield TBM Construction  
### The Transverse Vibration Trend of Double-Shield TBM Construction  
When the double-shield TBM reaches the monitoring section, the cutter-head is located directly below the measuring points, and the vibration peak acceleration is relatively large. Therefore, the vibration data at this time are selected to study the influence trend of double-shield TBM construction in the transverse section. Through time-domain curve analysis, the peak accelerations of all measuring points are obtained, as shown in Table 3 below. As can be seen from Table 3, the maximum peak acceleration of the surface measuring point 01 is 158.19 mm/s\({}^{2}\), which occurs in sampling hole Z-3. The direction of the maximum peak acceleration is the Y-direction, perpendicular to the tunnel axis. However, in measuring point 02 with a depth of 10 m, the maximum peak acceleration is at sampling hole Z-4, the value of which is 172.68 mm/s\({}^{2}\). The difference is that the direction of maximum peak acceleration is the Z-direction. Moreover, the peak acceleration of this measuring point in the X-direction is second only to the Z-direction, the value of which is 167.8 mm/s\({}^{2}\). Similarly, when the buried depth of the measuring point is 20 m, the maximum peak acceleration is 207.60 mm/s\({}^{2}\) in sampling hole Z-4, in the Z-direction. It can be seen that the maximum peak acceleration mainly occurs in the vertical Z-direction when double-shield TBM passes through the monitoring section. According to the above results of vibration monitoring, the three groups of peak acceleration curves with different burial depths are plotted as follows. From Figure 9a, we can see that the peak acceleration in the X, Y, and Z-directions are comparable, and the peak acceleration values of the sampling holes close to the tunnel axis, for instance, Z-3, Z-4, and Z-5 are significantly larger than several other sampling holes. Moreover, the farther measuring points are from the tunnel axis, the smaller the peak acceleration. The same rule can also be obtained at measuring points with a depth of 10 and 20 m, as shown in Figure 9b,c. However, there is a significant difference in peak acceleration between the three different buried depths in the Z-direction. As shown in Figure 9c, the peak acceleration in the Z-direction is significantly larger than that in the X and Y-directions when the sampling holes are close to the tunnel axis. As the buried depths of measuring points become smaller, the peak accelerations in the Z-direction gradually decrease. The reason is that the peak acceleration decays as it propagates from deep to \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline
**Sampling** & **Monitoring** & \multicolumn{3}{c}{**Peak Accelerations**} & \multicolumn{3}{c}{**Sampling**} & \multicolumn{3}{c}{**Monitoring**} & \multicolumn{3}{c}{**Peak Accelerations**} \\ \cline{3-10}
**Holes** & **Points** & **X** & **Y** & **Z** & **Holes** & **Points** & **X** & **Y** & **Z** \\ \hline \multirow{3}{*}{Z-2} & 01 & 56.55 & 38.68 & 57.80 & & 01 & 86.59 & 92.59 & 65.23 \\  & 02 & 126.01 & 79.71 & 90.26 & Z-6 & 02 & 67.87 & 87.60 & 49.44 \\  & 03 & 51.98 & 46.26 & 53.62 & & 03 & 106.1 & 116.91 & 85.30 \\ \hline \multirow{3}{*}{Z-3} & 01 & 136.79 & 158.19 & 120.62 & & 01 & 62.91 & 55.63 & 32.70 \\  & 02 & 147.36 & 72.62 & 104.57 & Z-7 & 02 & 90.52 & 63.65 & 37.69 \\  & 03 & 93.45 & 102.53 & 135.21 & & 03 & 70.25 & 23.30 & 30.63 \\ \hline \multirow{3}{*}{Z-4} & 01 & 96.51 & 110.79 & 103.30 & & 01 & 54.74 & 47.80 & 36.32 \\  & 02 & 167.8 & 122.97 & 172.68 & Z-8 & 02 & 77.35 & 56.33 & 53.60 \\  & 03 & 133.54 & 81.16 & 207.60 & & 03 & 45.07 & 49.59 & 38.42 \\ \hline \multirow{3}{*}{Z-5} & 01 & 140.75 & 122.02 & 111.12 & & 01 & 46.33 & 50.38 & 46.81 \\  & 02 & 128.97 & 64.41 & 132.59 & Z-9 & 02 & 82.44 & 52.27 & 36.83 \\ \cline{1-1}  & 03 & 121.19 & 121.61 & 168.50 & & 03 & 43.92 & 38.52 & 26.32 \\ \hline \hline \end{tabular}
\end{table}