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 excava-tion. 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 lique-faction 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 liquefac-tion properties of a stratum through which a tunnel passes is evaluated.%地震荷载作用下饱和砂土液化会导致隧道发生严重破坏,准确判定隧道穿越地层的可液化性并采取相应的抗液化措施能够有效降低隧道相应的震害.文章基于Seed判别法,采用数值仿真技术研究了隧道开挖前后周围地层液化性能的变化,结果表明,隧道的开挖扰动可显著降低地层的抗液化性能,拱底位置地层的降幅略小于拱腰位置;随着地层点远离隧道开挖区中心,隧道开挖对地层液化性能的影响逐渐减弱.同时,隧道埋深越大,隧道开挖对地层液化性能的影响越弱.在对隧道穿越地层可液化性进行判别时,应当考虑隧道开挖扰动的影响.研究成果可为隧道开挖区地层的可液化判别提供参考.
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