Effects of dynamic soil–tunnel interaction on seismic soil pressure and pore pressure
(2.Department of Civil Engineering, Tianjin University, Tianjin, China 300354)
【Abstract】This paper investigates the effects of dynamic soil–tunnel interaction on seismic soil and pore pressure with a method of indirect boundary element. The results are presented for different tunnel masses and depths as well as for different incident angles of seismic waves. The water-saturated poroelastic half-space is modeled as a two-phase medium based on the Biot’s theory. Furthermore, the seismic soil pressure between the water-saturated half-space case and the single-phase half-space case is compared to investigate the effect of the solid frame–pore water coupling. It is shown that the seismic soil pressure is evidently amplified due to the dynamic soil–tunnel interaction, and the horizontal soil pressure on the tunnel can be 1.7 times larger than that of the free field, while the vertical soil pressure can be 1.6 times larger. It is also shown that the solid frame–pore water coupling has a significant influence on the magnitude of the seismic soil pressure, and the maximum difference between the two-phase medium model and the single-phase medium model is up to 210% in this paper.
【Keywords】 water-saturated two-phase medium; indirect boundary element; dynamic soil–tunnel interaction; solid frame–pore water coupling; seismic soil pressure; seismic pore pressure;
 LI Xuehong, LIANG Chen, XU Xiuli, et al. Analysis of seismic response of complex multi-layer tunnel node structure [J]. Journal of Natural Disasters, 2018, 27 (2): 74–83 (in Chinese).
 GUAN Zhenchang, XU Qiu, DENG Tao. Seismic responses of large section tunnel with shallow cover and unsymmetrical loading [J]. Journal of Natural Disasters, 2018, 27 (3): 68–76 (in Chinese).
 HUANG Zhongkai, ZHANG Dongmei. Risk analysis of the seismic response of shield tunnel considering the above ground structure in soft deposits [J]. Journal of Natural Disasters, 2018, 27 (4): 67–74 (in Chinese).
 Hashash Y M A, Hook J J, Schmidt B, et al. Seismic design and analysis of underground structures [J]. Tunnelling and Underground Space Technology, 2001, 16 (4): 247–293.
 LIANG Jianwen, ZHU Jun. Seismic soil pressure on underground tunnel in transverse direction [J]. Earthquake Engineering and Engineering Dynamics, 2016, 36 (4): 54–69 (in Chinese).
 JIANG Luzhen, CHEN Jun, LI Jie, et al. Dynamic soil pressure method for underground structures [J]. Chinese Journal of Geotechnical Engineering, 2018, 40 (2): 305–312 (in Chinese).
 Ostadan F. Seismic soil pressure for building walls: an updated approach [J]. Soil Dynamics and Earthquake Engineering, 2005, 25 (7): 785–793.
 Tsinidis G. Response of urban single and twin circular tunnels subjected to transversal ground seismic shaking [J]. Tunnelling and Underground Space Technology, 2018 (76): 177–193.
 LIANG Jianwen, ZHU Jun. A FEM-IBEM coupling method for nonlinear seismic response analysis of underground structures in water-saturated soft soils [J]. Chinese Journal of Geotechnical Engineering, 2018, 40 (11): 1977–1987 (in Chinese).
 XU Zhiying. The effective stress method for dynamic soil–underground structure interaction analysis [J]. Journal of Hydraulic Engineering, 1993 (10): 59–63 (in Chinese).
 ZHOU Jian, DONG Peng, CHI Yong. Research on seismic soil pressure of underground structures in soft soils [J]. Rock and Soil Mechanics, 2004, 25 (4): 554–559 (in Chinese).
 Tamari Y, Towhata I. Seismic soil–structure interaction of cross sections of flexible underground structures subjected to soil liquefaction [J]. Soils & Foundations, 2003, 43 (2): 69–87.
 Bobet A. Drained and undrained response of deep tunnels subjected to far-field shear loading [J]. Tunnelling and Underground Space Technology, 2010, 25 (1): 21–31.
 Biot M A. Theory of propagation of elastic waves in a fluid-saturated porous solid (I): Low frequency range [J]. Journal of the Acoustical Society of America, 1956, 28 (2): 168–178.
 Lin C, Lee V W, Trifunac M D. The reflection of plane waves in a poroelastic half-space saturated with inviscid fluid [J]. Soil Dynamics and Earthquake Engineering, 2005, 25 (3): 205–223.
 Liang J, Fu J, Todorovska M I, et al. In-plane soil–structure interaction in layered, fluid-saturated, poroelastic half-space I: Structural response [J]. Soil Dynamics and Earthquake Engineering, 2016 (81): 84–111.
 Wolf J P. Dynamic soil–structure interaction [M]. Englewood Cliffs, NJ: Prentice-Hall, 1985: 119–131.
 Luco J E. On the relation between radiation and scattering problems for foundations embedded in an elastic half-space [J]. Soil Dynamics and Earthquake Engineering, 1986, 5 (2): 97–101.
 Luco J E, Wong H L. Seismic response of foundations embedded in a layered half-space [J]. Earthquake Engineering & Structural Dynamics, 1987, 15 (2): 233–247.