###### Abstract  
The dewatering of foundation pits leads to changes in the water level and effective stress within the surrounding strata. When existing tunnels are present within the dewatering influence zone, the impact of dewatering on these tunnels cannot be ignored. The Vlasov foundation beam model was used to simulate the interaction between the tunnel and the soil, and the key parameters of the model were precisely investigated. In addition, the constraining effect of the lateral soil on the tunnel was also considered. By integrating the principles of effective stress and [PERSON]'s assumption, in this work we calculated the additional load on the tunnel caused by foundation pit dewatering, which was then applied to determine the tunnel stress and deformation induced by dewatering. The accuracy of this approach is validated through comparative analysis with finite element results. Furthermore, the relationships between the permeability coefficient (\(k_{\text{t}}\)), the spacing (\(d\)) between the tunnel and the dewatering well, the water level drop (\(s_{\text{w}}\)), and tunnel stress and deformation were further studied. The key findings are summarized as follows. Firstly, accounting for lateral soil effects enhances computational accuracy. Secondly, an increase in soil \(k_{\text{t}}\) leads to a greater tunnel settlement with relatively minor changes in bending moments. Thirdly, as d increases, both tunnel settlements and bending moments decrease. Additionally, as the water level dropped from 10 m to 30 m, the maximum additional stress on the tunnel increased by 94.50%, and the settlement increased by 127.43%. Consequently, it is essential to pay close attention to the tunnel segment nearest to the water level. foundation pit dewatering; existing tunnel; effective stress principle; effects of lateral soil; Vlasov foundation model +
Footnote †: journal: Applied Sciences  
finite element simulation to investigate the influence of pressure reduction and confined layer dewatering on the structural integrity of existing shield tunnels. [PERSON] et al. [11] developed a numerical model to examine the effects of underground dewatering on nearby subway tunnels. In accordance with practical engineering applications, [PERSON] et al. [12] employed the finite element method to assess the structural impact of foundation pit dewatering on tunnels. Additionally, [PERSON] [13] and [PERSON] [14] conducted numerical calculations to comprehensively analyze and investigate deformation and stress patterns in existing tunnels under various underground dewatering scenarios. [PERSON] et al. [15] deduced the analytical solution of the vertical displacement of adjacent tunnels under pre-dewatering disturbance by using a two-stage analysis method. [PERSON] et al. [16] utilized a two-stage analytical method to derive solutions for assessing the deformation of adjacent pipelines resulting from single-well dewatering. Furthermore, [PERSON] et al. [17] evaluated tunnel deformation directly beneath foundation pits during excavations and dewatering, applying the Pasternak foundation beam model. Their findings underscore the significance of recognizing the impact of dewatering on underlying tunnels. In theoretical studies concerning the deformation of shield tunnels, the elastic foundation beam model is a widely employed framework for simulating the interaction between tunnels and the surrounding soil. For the methods, the shear layer's shear modulus and the coefficient of the subgrade modulus strongly influence simulation results, which can explain their crucial roles in determining the ability of the elastic foundation to withstand shear deformation and compression deformation. However, these two parameters are often determined by various empirical equations [18; 19; 20; 21], which may fail to accurately portray the interaction between the soil and the tunnel and result in subjective or biased results.