Numerical model verification and calibration of George Massey Tunnel using centrifuge models

Yang, Diange; Naesgaard, Ernest; Byrne, Peter; Adalier, Korhan; Abdoun, Tarek

doi:10.1139/t04-039

Cited by 69 publications

(20 citation statements)

References 5 publications

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“…The possibility of uplift of underground structures in a major earthquake was supported by several numerical and experimental analyses. Numerical analyses carried out by Yang et al [5] on the George Massey Tunnel and Sun et al [6] on the BART tunnel showed significant floatation. However, these analyses were carried out for very specific cases and site conditions.…”

Section: Introductionmentioning

confidence: 92%

Finite Element Analysis of Floatation of Rectangular Tunnels Following Earthquake Induced Liquefaction

Madabhushi

2014

Indian Geotech J

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Underground structures such as tunnels, pipelines, car parks etc. can suffer severe damage during strong earthquake events. As many of these structures are buoyant, soil liquefaction due to earthquake loading can result in their floatation. In this paper, the floatation of rectangular tunnels, normally constructed by the cut-and-cover method, is investigated using dynamic finite element analyses. Sinusoidal and more realistic earthquake input motions are considered. The acceleration response of the tunnel and the soil surface following soil liquefaction is investigated. The generation of excess pore pressures in the soil around the tunnel and the consequent floatation of the tunnel are observed for both types of input motions. It will be shown that the amount of tunnel uplift depends on the type of input motion with the sinusoidal motion leading to a significantly larger uplift compared with the more realistic Kobe motion. Further, the effect of soil permeability on the floatation of the rectangular tunnel is investigated. It will be shown that tunnels can suffer floatation in finer soils with low permeabilities, whilst coarser soils with high permeability can lead to tunnel settlements owing to the rapid re-consolidation of the liquefied soils. The average axial strains in the soil above the tunnel will be shown to decrease with decreasing permeability.

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Section: Introductionmentioning

confidence: 92%

Finite Element Analysis of Floatation of Rectangular Tunnels Following Earthquake Induced Liquefaction

Madabhushi

2014

Indian Geotech J

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“…There was a conflict between the dynamic and permeability time scales. To solve the problem, methyl cellulose fluid was introduced to reduce the permeability of soil [26]. Methyl cellulose fluid was introduced at a rate of 0.1 L/h into the model foundation when cooling down, which was slow enough to avoid the sand boiling phenomenon.…”

Section: Model Preparationmentioning

confidence: 99%

Application of particle image velocimetry (PIV) in the study of uplift mechanisms of pipe buried in medium dense sand

Huang

Ling

et al. 2015

J Civil Struct Health Monit

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Geotechnical centrifuge modeling, which can effectively simulate the stress field of soil in the prototype, was adopted to help investigate the effects of the uplifting of pipes buried at different depths within a medium dense sand under (1) a static state and (2) a dynamic state. To acquire the displacement vector fields and strain contours in the soil around pipes, particle image velocimetry technology was applied. The study focused on the deformation mechanisms of soil surrounding the pipes and ground surface. Two different deformation triggers, external forces and soil liquefaction, were considered. When uplifting was caused by an external force, the relationship between the soil deformation and uplift resistance was similar to the typical ground load-deformation characteristic relationships. There was little displacement of soil during the elastic stage. Along with the uplifting of the pipe, a plastic zone within the range of one pipe diameter (1D) above the pipe appeared in the soil at peak resistance. During the post-peak period, a shear failure plane extended upwards to the ground surface, at an inclined angle forming a trumpetlike shape. The ground surface deformation range expanded according to the buried depth of the pipe. Meanwhile, in a liquefied field, the soil flowed within a heart-shaped region around the pipe. The soil deformation region surrounding a shallow buried pipe, with a width of 5D-6D, was far larger than that found for a pipe buried at the same depth in a static field. Both heave and settlement could be observed on the ground surface.

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“…They concluded that the placement of coarse backfill above underground pipes can reduce their uplift displacements caused by soil liquefaction. Yang et al (2004) performed centrifuge and numerical analyses for the case of the George Massey Tunnel in British Columbia, and proposed applying densification or gravel drainage columns on either side of the box tunnel. Both methods produced a reduction in uplift displacement of the structure.…”

Section: Stone Column/coarse Backfillmentioning

confidence: 99%

Remediation against floatation of underground structures

Chian¹,

Madabhushi²

2013

Proceedings of the Institution of Civil Engineers - Ground Impr

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Underground structures located in liquefiable soil deposits are susceptible to floatation following an earthquake event due to their lower unit weight relative to the surrounding saturated soil. Centrifuge tests have been carried out to assess the effectiveness of existing remediation techniques in reducing the uplift of underground structures, namely in situ densification and the use of coarse sand backfill. The centrifuge test results showed that these methods do reduce the uplift displacement of buoyant structures. Their performance was thereafter linked to the theoretical mechanism of floatation of underground structures. Based on the understanding from preceding tests, a further improvement on the use of the coarse sand backfill was carried out, which produced a greater reduction in the uplift displacement of the structure. Each of these techniques, however, does pose issues when applied in the field, such as possible damage to surrounding structures, construction issues and maintenance problems.

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Numerical model verification and calibration of George Massey Tunnel using centrifuge models

Cited by 69 publications

References 5 publications

Finite Element Analysis of Floatation of Rectangular Tunnels Following Earthquake Induced Liquefaction

Finite Element Analysis of Floatation of Rectangular Tunnels Following Earthquake Induced Liquefaction

Application of particle image velocimetry (PIV) in the study of uplift mechanisms of pipe buried in medium dense sand

Remediation against floatation of underground structures

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