Centrifuge tests to assess seismic site response of partially saturated sand layers
Centrifuge tests to assess seismic site response of partially saturated sand layers
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DOI：
10.1016/j.soildyn.2017.01.024
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发表时间：
2017-03
影响因子：
4
通讯作者：
M. Mirshekari;M. Ghayoomi
中科院分区：
文献类型：
--
作者：
M. Mirshekari;M. Ghayoomi
非饱和土层的地震响应可能与饱和或干燥土层的地震响应不同。进行了一组离心机实验来研究部分饱和对北岭地震下砂层地震响应的影响。实施稳态渗透以控制并提供深度均匀的饱和度剖面。土壤表面峰值地面加速度的放大程度与饱和度成反比，特别是在低周期范围内。在具有较高吸力的非饱和土壤中，运动的累积强度放大也较高。刚度较高的部分饱和砂土的侧向变形和地表沉降一般低于干土。尽管忽略砂层部分饱和的影响对于地震变形可能是保守的，但它可能会导致低估表面设计谱。
Seismic response of unsaturated soil layers may differ from that of saturated or dry soil deposits. A set of centrifuge experiments was conducted to study the influence of partial saturation on seismic response of sand layers under scaled Northridge earthquake motion. Steady state infiltration was implemented to control and provide uniform degree of saturation profiles in depth. The amplification of peak ground acceleration at the soil surface was inversely proportional to the degree of saturation, especially in low period range. The cumulative intensity amplification of the motion was also higher in unsaturated soils with higher suctions. The lateral deformation and surface settlement of partially saturated sand with higher stiffness were generally lower than that in dry soil. Although neglecting the effect of partial saturation in sand layers might be conservative with respect to seismic deformations, it may result in underestimating the surface design spectra.