Abstract The 2008 Wenchuan earthquake caused widespread liquefaction of gravelly soils (i.e., gravelly sands and sandy gravels), which phenomena show many differences compared to those of typical sands. To study the liquefaction mechanism and triggering evaluation of gravelly soils during this event, comprehensive case studies with measurement of shear wave velocity on both liquefied and non-liquefied sites were carried out according to a suite of recommended procedures for site investigation, field testing and data processing. Three typical cases were provided to illustrate the distinct characteristics of ground motion, liquefaction manifestation, soil profiles and field testing, and explore the possible mechanisms of liquefaction. Eighty-one well identified case histories were obtained, which feature the updated estimation of ground motion parameters from the USGS ShakeMap and the probabilistic treatment of the datasets. The preliminary analyses on liquefaction triggering boundary curves, shear wave velocities of these case histories and the applicability of the Ishihara criterion (1985) indicate that the gravel content plays a key role in the liquefaction mechanism and the consequences of gravelly soil deposits, and the liquefaction evaluation of gravelly sands and sandy gravels should be treated separately.

中文翻译：

---

2008年汶川地震中砾石土液化案例研究

摘要 2008年汶川地震导致砂砾土（即砾砂和砂砾）大面积液化，与典型砂土相比，这种现象有很大的不同。为了研究此次事件中砾石土的液化机制和触发评估，根据一套推荐的场地调查、现场测试和数据程序，对液化和非液化场地的剪切波速度进行了综合案例研究加工。通过三个典型案例来说明地震动、液化表现、土壤剖面和现场测试的鲜明特征，并探讨液化的可能机制。获得了 81 个明确的病例史，其特点是对来自 USGS ShakeMap 的地面运动参数的更新估计和数据集的概率处理。对液化触发边界曲线、这些案例历史的剪切波速度和 Ishihara 准则（1985）的适用性的初步分析表明，砾石含量在液化机制和砾石土壤沉积的后果中起着关键作用，液化砾石砂和砂砾石的评价应分别处理。