Optimization of surficial settlement originated from the excavation of twin tunnels on surface structures with finite dimensions
Subject Areas : Structural Engineering
1 - Department of Civil Engineering, Qazvin Branch, Islamic Azad University, Qazvin, Iran
Keywords: Optimization, surficial settlement, twin tunnels, structure with finite dimensions,
Abstract :
In urban regions, the stability and safety of surface structures are essential. With the development of cities and increasing building density in metropolitan areas, the construction of underground structures like subway tunnels will be considered more and more. The tunnels are located close to the ground surface in most urban regions. Therefore, excavating these tunnels causes some displacements in the soils around the tunnels, leading to some adverse effects on the surface structures. Predicting deformations looks essential to reducing these effects, showing the importance of tunnel and structure interaction. In this paper, using three-dimensional numerical simulation and parametric studies, the effect of various parameters on the displacement of tunnels and their adjacent buildings are studied. The optimum surface settlement values are predicted using the neural network and developed optimization algorithms. The parameters under study are composed of: the horizontal distance between tunnels, the depth of tunnels, the angle between tunnels, the excavation distance between two tunnels, the diameter of the tunnels, tunnels' contraction, the soil's internal friction angle, and the soil's cohesion. Using a neural network and optimization algorithms can considerably help optimize the design and significantly reduce adverse effects on the surface structures during the tunnel excavation. The results from the neural network showed that the optimum state of displacement happens when the soil's cohesion, tunnels' contraction, diameter, and depth are the minimum values, and the excavation distance between two tunnels is the maximum value.
[1] Haji, T. K., Marshall, A. M., &Tizani, W. (2018). A cantilever approach to estimate bending stiffness of buildings affected by tunnelling. Tunnelling and Underground Space Technology, 71, 47-61.
[2] Haji, T. K., Marshall, A. M., &Franza, A. (2018). Mixed empirical-numerical method for investigating tunnelling effects on structures. Tunnelling and Underground Space Technology, 73, 92-104.
[3] Boldini, D., Losacco, N., Bertolin, S., &Amorosi, A. (2018). Finite Element modelling of tunnelling-induced displacements on framed structures. Tunnelling and Underground Space Technology, 80, 222-231.
[4] Wang, Z., Zhang, K. W., Wei, G., Li, B., Li, Q., & Yao, W. J. (2018). Field measurement analysis of the influence of double shield tunnel construction on reinforced bridge. Tunnelling and Underground Space Technology, 81, 252-264.
[5] Zhang, Z., Huang, M., Xu, C., Jiang, Y., & Wang, W. (2018). Simplified solution for tunnel-soil-pile interaction in Pasternak's foundation model. Tunnelling and Underground Space Technology, 78, 146-158.
[6] Nematollahi, M., & Dias, D. (2019). Three-dimensional numerical simulation of pile-twin tunnels interaction–Case of the Shiraz subway line. Tunnelling and Underground Space Technology, 86, 75-88.
[7] Fabozzi, S., Bilotta, E., Yu, H., & Yuan, Y. (2018). Effects of the asynchronism of ground motion on the longitudinal behaviour of a circular tunnel. Tunnelling and Underground Space Technology, 82, 529-541.
[8] Jallow, A., Ou, C. Y., & Lim, A. (2019). Three-dimensional numerical study of long-term settlement induced in shield tunneling. Tunnelling and Underground Space Technology, 88, 221-236.
[9] Moussaei, N., Khosravi, M. H., & Hossaini, M. F. (2019). Physical modeling of tunnel induced displacement in sandy grounds. Tunnelling and Underground Space Technology, 90, 19-27.
[10] Zhang, T., Taylor, R. N., Divall, S., Zheng, G., Sun, J., Stallebrass, S. E., &Goodey, R. J. (2019). Explanation for twin tunnelling-induced surface settlements by changes in soil stiffness on account of stress history. Tunnelling and Underground Space Technology, 85, 160-169.
[11] Nematollahi, M., & Dias, D. (2020). Interaction between an underground parking and twin tunnels–Case of the Shiraz subway line. Tunnelling and Underground Space Technology, 95, 103150.
[12] Zheng, G., Tong, J., Zhang, T., Wang, R., Fan, Q., Sun, J., & Diao, Y. (2020). Experimental study on surface settlements induced by sequential excavation of two parallel tunnels in drained granular soil. Tunnelling and Underground Space Technology, 98, 103347.
[13] Lu, D., Lin, Q., Tian, Y., Du, X., & Gong, Q. (2020). Formula for predicting ground settlement induced by tunnelling based on Gaussian function. Tunnelling and Underground Space Technology, 103, 103443.
[14] Bilotta, E., Paolillo, A., Russo, G., & Aversa, S. (2017). Displacements induced by tunnelling under a historical building. Tunnelling and Underground Space Technology, 61, 221-232.
[15] Miliziano, S., & de Lillis, A. (2019). Predicted and observed settlements induced by the mechanized tunnel excavation of metro line C near S. Giovanni station in Rome. Tunnelling and Underground Space Technology, 86, 236-246.
[16] Kovačević, M. S., Bačić, M., Gavin, K., & Stipanović, I. (2021). Assessment of long-term deformation of a tunnel in soft rock by utilizing particle swarm optimized neural network. Tunnelling and Underground Space Technology, 110, 103838.
[17] Meng, F., Chen, R., Xu, Y., Wu, H., & Li, Z. (2021). Centrifuge modeling of effectiveness of protective measures on existing tunnel subjected to nearby excavation. Tunnelling and Underground Space Technology, 112, 103880.
[18] Zhou, Z., Ding, H., Miao, L., & Gong, C. (2021). Predictive model for the surface settlement caused by the excavation of twin tunnels. Tunnelling and Underground Space Technology, 114, 104014.
[19] Mu, B., Xie, X., Li, X., Li, J., Shao, C., & Zhao, J. (2021). Monitoring, modelling and prediction of segmental lining deformation and ground settlement of an EPB tunnel in different soils. Tunnelling and Underground Space Technology, 113, 103870.
[20] Azadi, M., Pourakbar, S., &Kashfi, A. (2013). Assessment of optimum settlement of structure adjacent urban tunnel by using neural network methods. Tunnelling and underground space technology, 37, 1-9.
[21] Moosazadeh, S., Namazi, E., Aghababaei, H., Marto, A., Mohamad, H., &Hajihassani, M. (2018). Prediction of building damage induced by tunnelling through an optimized artificial neural network. Engineering with Computers, 1-13.
[22] Moghaddasi, M. R., &Noorian-Bidgoli, M. (2018). ICA-ANN, ANN and multiple regression models for prediction of surface settlement caused by tunneling. Tunnelling and Underground Space Technology, 79, 197-209.
[23] Azadi, M., & Hosseini, S. M. M. (2007). The impact of underground tunnel excavation on adjacent buildings during earthquake case study: shiraz underground, Iran. Electronic Journal of Geotechnical Engineering, 12, 1-10.
[24] Azadi, M., & Hosseini, S. M. M. (2010). Analyses of the effect of seismic behavior of shallow tunnels in liquefiable grounds. Tunnelling and underground space technology, 25(5), 543-552.
[25] Mir Mohammad Hosseini, S. M., & Azadi, M. (2012). Effect of the location of liquefiable sand lenses on shallow tunnels during earthquake loading. Arabian Journal for Science and Engineering, 37, 575-586.