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Effects of Tunnel Excavation Distrurbance on the Liquefiable Properties of Surrounding Stratum
(1 State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan 430071; 2 Geotechnical and Structural Engineering Research Center, Shandong University, Jinan 250061)
Abstract Saturated sand soil liquefaction may cause severe damage to tunnels under seismic loading. Accurately evaluating the liquefaction properties of the strata through which tunnels pass and taking anti-liquefaction measures can effectively reduce the seismic damages to tunnels. Based on the Seed method, a numerical simulation technique is used to analyze the changes to the liquefaction properties of surrounding stratum before and after tunnel excavation. The results show that: excavation disturbance can effectively reduce the liquefaction resistance of a stratum, and the reduction degree of the liquefaction resistance at the bottom is a little bit smaller than that of the haunch; with the increase of distance away from the tunnel excavation center, the influence of tunnel excavation on the liquefaction properties of a stratum decreases; the larger the overburden, the less effect excavation has on the liquefaction properties of the stratum; the influence of the excavation disturbance should be taken into account when the liquefaction properties of a stratum through which a tunnel passes is evaluated.
Abstract：
Saturated sand soil liquefaction may cause severe damage to tunnels under seismic loading. Accurately evaluating the liquefaction properties of the strata through which tunnels pass and taking anti-liquefaction measures can effectively reduce the seismic damages to tunnels. Based on the Seed method, a numerical simulation technique is used to analyze the changes to the liquefaction properties of surrounding stratum before and after tunnel excavation. The results show that: excavation disturbance can effectively reduce the liquefaction resistance of a stratum, and the reduction degree of the liquefaction resistance at the bottom is a little bit smaller than that of the haunch; with the increase of distance away from the tunnel excavation center, the influence of tunnel excavation on the liquefaction properties of a stratum decreases; the larger the overburden, the less effect excavation has on the liquefaction properties of the stratum; the influence of the excavation disturbance should be taken into account when the liquefaction properties of a stratum through which a tunnel passes is evaluated.
2016, Vol. 53 