基于CPT的液化侧向位移 (lateral displacement) 估算
1. 引言
2. 液化分析方法
Robertson and Wride (1998) Evaluating Cyclic Liquefaction Potential Using the Cone Penetration Test.
Robertson (2009) Interpretation of cone penetration tests – a unified approach.
(2) Idriss and Boulanger
Idriss and Boulanger (2008) Soil Liquefaction during Earthquakes.
Boulanger and Idriss (2014) CPT and SPT based liquefaction triggering procedures.
(3) Moss
Moss et al. (2006) CPT-based probabilistic and deterministic assessment of in situ seismic soil liquefaction potential.
(1) Yoshimine 等人（2006）
(2) Zhang, Robertson and Brachman (2004)
Zhang等人 (2004)计算的不是侧向位移的绝对值，而是一个相对值LDI(Lateral Displacement Index)，作者们称之为侧向位移指数，尽管LDI的单位是cm，但这个数值不是真实的侧向位移量。
引自论文原话："Although LDI has the units of displacement, it is intended only to provide an index to quantify potential lateral displacements for a given soil profile, soil properties, and earthquake characteristics. The actual magnitude of lateral displacement depends on both LDI and geometric parameters characterizing ground geometry. "(虽然 LDI 以位移为单位，但其目的只是提供一个指数，以量化特定土层、土特性和地震特征的潜在侧向位移。侧向位移的实际大小取决于 LDI 和表征地面几何特征的几何参数)。
先前建立的坝体模型长度共194米，有6个坡度变化段，其中最大的坡度是在坝体的最高端，坡度S=1:4.76=21%，显然不属于“Gently slope ground”, 因此使用"Level ground with free face"方法计算LDI.
测得这段边坡的H=2m, L=11m, 四种方法计算的LDI最大值为7.0m，最小值为1.5m，离散性较大。如果按照LDI=1.5计算，真实的侧向位移LD=2.3m。
