# Surface Settlement during Tunneling: Field Observation Analysis
## 2 Materials and Methods  
In previous work [39; 40; 41; 42], we presented the results of the geotechnical monitoring of the settlement of buildings and structures in the area of influence of the tunneling works. Here, an additional study of the well-known data was conducted to identify the relationship between the supplementary displacements and the following factors: the depth and distance in the plan from the tunnel axis to the monitored object, the class and type of the face soil, the TBM diameter, and the loading that comes from the buildings and structures affected by the works. The analysis was performed using vertical displacement data for about 30 construction facilities, including residential and public buildings, crosswalks, and ballast sections of public railroad tracks. The tunnels of the Big Circular Line and Nekrasovskaya Line of the Moscow underground were bored into the rock soil and soft ground using TBMs with cutting diameters of 6 and 10 m.  
In addition, during the tunneling of the Rublevo-Arkhangelskaya line, we collected the monitoring data and engineering information on the tunneling parameters: the earth pressure and the shield advance considering the installation of the tunnel's bearing structures. During the construction of a new line of the Moscow underground that has two single-track tunnels with an external diameter Dex = 6.3 m, a Robbins EPB 2110/378 earth pressure tunnel boring machine was used; its cutting diameter was 6.59 m. During the construction of the lefthand tunnel, tunnel monitoring data were collected for the buildings on the daylight surface, the tunnel boring advance rate, and the tunnel bearing structure \begin{table}
\begin{tabular}{c c c} \hline \hline
**Factor No.** & **Group of Influence** & **Factor** \\ \hline
1 & & Physical–mechanical properties of soils [17; 18; 19; 20] \\ \hline
2 & & Rheological properties of soils [21] \\ \hline
3 & & **Class and type of soil \({}^{*}\)**[15; 17; 22; 23] \\ \hline
4 & & Thickness of soil layers above the tunnel [24; 25] \\ \hline
5 & & Ground water level [20; 23; 24; 25] \\ \hline
6 & & **Tunnel diameter \({}^{*}\)**[18; 23; 26; 27] \\ \hline
7 & & Tunnel slope [26; 27; 28] \\ \hline
8 & & **Tunnel depth \({}^{*}\)**[15; 18; 23; 26; 30; 31] \\ \hline
9 & & **Distance between the tunnel and the monitored** \\ \hline
10 & & **Loading that comes from the building in the area of** \\  & & **influence \({}^{*}\)**[20; 24; 25; 27] \\ \hline
11 & & **Pressure balance \({}^{*}\)**[21; 24; 25; 27; 28; 29; 32; 33; 34; 35; 36] \\ \hline
12 & & Injection rate and injected amount; modulus of elasticity \\  & & of the grout [19; 20; 24; 25; 32; 33; 34; 36; 37; 38] \\ \hline
13 & & **Advance rate of the boring machine \({}^{*}\)**[19; 23; 24; 25; 32] \\ \hline
14 & & Rotary table torque [19; 24; 25; 34; 35] \\ \hline \end{tabular} \({}^{*}\) Factors considered in this article.  
\end{table} 
Table 1: The factors belonging to each group of potential influence on the supplementary displacement of the soil body in the process of tunneling. installation time, as well as the average earth pressure during the installation of each 1.2-m wide liner ring in the design position. The investigated section of the tunnel's longitudinal profile (Figure 1) was composed of sandy soils from the crown to the ground surface. However, the machine cutter contained predominantly clay soils. The distance from the tunnel top to the daylight surface varied from 23 to 29 m.  
The determination of the technological parameter of the tunneling, the earth pressure, was calculated using the geological engineering benchmark data and design documents, according to the method presented in the Industry-wide Standard 2.27.19-2011 \"Tunnel construction using tunnel boring machines and high-precision lining techniques\", issued by the National Association of Builders [7]. At the same time, as the TBM approached the monitoring object, large increments of deformations were recorded.