Analyses of the effect of seismic behavior of shallow tunnels in liquefiable grounds

Azadi, Mohammad; Hosseini, S. Majdeddin Mir Mohammad

doi:10.1016/j.tust.2010.03.003

Cited by 60 publications

(14 citation statements)

References 15 publications

(32 reference statements)

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“…From Figure 6a and Figure 6b, it can be seen that, as the amplitude of the IM increases from 0.1 g to 0.5 g, the surface heave increases from 0.011 m to 0.105 m. The increase in the amplitude of IM results in a greater tunnel uplift as compared to the surface heave, which is minimal at the lower amplitudes but more pronounced at the higher amplitudes. This trend also follows a similar pattern as obtained by Azadi and Hosseini [8].…”

Section: Effect Of the Variation In The Amplitude Of The Input Motionsupporting

confidence: 89%

“…It also results in the reduced surface heave with increased resistance to seismic-induced bending moments, which can be seen in Figure 4a-d. The results show a similar trend obtained in the reference study [16] and by Azadi and Hosseini [8]. From the figures, it is evident that the tunnel complex with thicker lining has greater resistance to the seismic-induced uplift, distortions, and bending moments.…”

Section: Effect Of the Variation In Lining Thicknesssupporting

confidence: 85%

“…Hashash and Hook et al [5] and Hashash and Park et al [6] conducted an extensive review of the available methods used to determine seismic induced forces that aid in the seismic design of different tunnels. Liu and Song [7] and Azadi and Hosseini [8] studied the seismic behavior of shallow tunnels subjected to horizontal and vertical shaking in the liquefiable sands in order to assess the distortions occurring in the tunnel lining and its uplift due to excess pore pressure generation. Unutmaz [9] investigated the liquefaction possibilities of soil surrounding the tunnels using 3D finite element modeling (FEM) and studied the acceleration variations and the power spectra developed under the seismic vibrations for various tunnel embedment depths.…”

Section: Of 22mentioning

confidence: 99%

“…The damping coefficients are calculated individually for each of the soil layers incorporated into the constitutive model definition. The tunnel lining and inner supporting structure are modeled using linear elastic plate elements as used by many other researchers in the past [8,9,16,17]. The Elastic modulus is taken as 37 MPa while the unit weight of concrete and the Poisson's ratio are taken as 25 kN/m 3 and 0.2, respectively.…”

Section: Constitutive Model and Boundary Conditionsmentioning

confidence: 99%

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Seismic Behavior of Triple Tunnel Complex in Soft Soil Subjected to Transverse Shaking

et al. 2020

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Combining multiple tunnels into a single tunnel complex while keeping the surrounding area compact is a complicated procedure. The condition becomes more complex when soft soil is present and the area is prone to seismic activity. Seismic vibrations produce sudden ground shaking, which causes a sharp decrease in the shear strength and bearing capacity of the soil. This results in larger ground displacements and deformation of structures located at the surface and within the soil mass. The deformations are more pronounced at shallower depths and near the ground surface. Tunnels located in that area are also affected and can undergo excessive distortions and uplift. The condition becomes worse if the tunnel area is larger, and, thus, the respective tunnel complex needs to be properly evaluated. In this research, a novel triple tunnel complex formed by combining three closely spaced tunnels is numerically analyzed using Plaxis 2D software under variable dynamic loadings. The effect of variations in lining thickness, the inner supporting structure, embedment depth on the produced ground displacements, tunnel deformations, resisting bending moments, and the developed thrusts are studied in detail. The triple tunnel complex is also compared with the rectangular and equivalent horizontal twin tunnel complexes in terms of generated thrusts and resisted seismic-induced bending moments. From the results, it is concluded that increased thickness of the lining, inner structure, and greater embedment depth results in decreased ground displacements, tunnel deformations, and increased resistance to seismic-induced bending moments. The comparison of shapes revealed that the triple tunnel complex has better resistance against moments with the least amount of thrust and surface heave produced.

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Section: Effect Of the Variation In The Amplitude Of The Input Motionsupporting

confidence: 89%

Section: Effect Of the Variation In Lining Thicknesssupporting

confidence: 85%

Section: Of 22mentioning

confidence: 99%

Section: Constitutive Model and Boundary Conditionsmentioning

confidence: 99%

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Seismic Behavior of Triple Tunnel Complex in Soft Soil Subjected to Transverse Shaking

et al. 2020

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“…Therefore, the numerical simulation has been gradually favored and applied by scholars in the study of tunnel vibration response analysis. After the Wenchuan earthquake, the vibration response of tunnel portal and shallow tunnels under earthquake vibration [4,5] , analysis of Shallow Excavation Tunnel in alluvium under lateral seismic loading [6] , the influence of liquefiable site, depth and section on aseismic performance of shallow tunnels [7,8] and others are all studied in detail based on the finite difference method. Based on finite difference software named FLAC/FLAC 3D, Huang et al [9] studied the dynamic time-history response of a shallow bias tunnel under horizontal seismic action.…”

Section: Introductionmentioning

confidence: 99%

Seismic Analysis of Shallow Tunnel in Bad Ground with the Numerical Simulation Method

Zhang¹,

Ruyue²,

Tangyong³

et al. 2018

2018 3rd International Conference on Mechatronics and Information Technology (ICMIT 2018)

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Seismic damages of the tunnel show that surrounding rock of shallow tunnel is mostly of a low grade and its stability is poor. The shallow tunnel is susceptible to earthquake. The dynamic calculation of the shallow tunnel in bad ground is performed by establishing a two-dimensional numerical model and using viscoelastic artificial boundary to simulate the dynamic boundary. Acceleration distribution in surrounding rock, the inner force variation of lining structure and the seismic displacement of surrounding rock are all analysed. The results show that the acceleration of surrounding rock increases with the decrease of the distance from the ground surface. The acceleration at ground surface is about 1.5 times at vault of tunnel and the acceleration of surrounding rock is gradually reduced from the tunnel structure to the model boundary. The horizontal displacement of surrounding rock keeps decreasing when its location moves away from the tunnel, and the displacement at each point increases with the shaking time and shaking intensity. Under seismic loading, the axial force and bending moment change most obviously at spandrel and arch foot of tunnel where the lining structure should be strengthened.

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Numerically liquefaction analysis of tunnel‐sand pile interaction (TSPI) under seismic excitation

Haque

2023

Geomechanics and Tunnelling

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Liquefaction is a vital issue for the tunnel‐sand pile interaction (TSPI) system under seismic excitation. Therefore the present study proposed a TSPI model for the liquefaction analysis numerically using the numerical code of Plaxis 3D under local seismic excitation. Validation results of the numerical code inform a convincing level of accuracy to ensure the analysis of the TSPI model using this code. In this research, the geometry of the TSPI model is considered smaller compared to the tunnel diameter to influence the probability of the liquefaction occurrence, and the only variable geometric dimension is the tunnel pile clear distance of the interaction zone while other geometric and material properties are considered to be the standard value. UBC3D‐PLM (two yield surfaces consisting of kinematic hardening rules) constitutive model is used to ensure the liquefaction effect in the TSPI model; however, the excess pore pressure ratio exceeds the limiting value of 1 to inform the existence of liquefaction in the TSPI model. In addition, the uplift of sand is exceeded from the settlement due to liquefaction. However, further investigations such as experimental and analytical studies may have to be performed in the future to enhance the present study.

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Analyses of the effect of seismic behavior of shallow tunnels in liquefiable grounds

Cited by 60 publications

References 15 publications

Seismic Behavior of Triple Tunnel Complex in Soft Soil Subjected to Transverse Shaking

Seismic Behavior of Triple Tunnel Complex in Soft Soil Subjected to Transverse Shaking

Seismic Analysis of Shallow Tunnel in Bad Ground with the Numerical Simulation Method

Numerically liquefaction analysis of tunnel‐sand pile interaction (TSPI) under seismic excitation

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