Cav5-Based Soil Liquefaction Study with Centrifuge Modeling: Including a Scenario-Based Soil Liquefaction Assessment for Taipei Metropolitan Areas(1/3)

A variety of studies have been reported for soil liquefaction assessment and hazard mitigation. According to a recent study, a ground motion intensity measure called CAV5 (cumulative absolute velocity with a 0.005 g cutoff) was found having a strong correlation with pore pressure buildup in soil, and therefore it is suggested to be utilized in soil liquefaction assessment. However, what was missed in such studies is the correlation model between CAV5 and soil liquefaction potential. As a result, the first objective of the proposed research is to establish a model that can estimate soil liquefaction potential for a given CAV5, which is referred to as Part I of the research. Next, the research will apply the newly developed logistic model to evaluate soil liquefaction probability in Taipei metropolitan areas subject to a scenario that the Shanchiao fault in Taipei could induce a major earthquake, which is the Part II of the study.The methodology for developing the new CAV5-based soil liquefaction model (Part I) is based on experiments. Specifically, a series of centrifuge tests will be conducted in Geotechnical Centrifuge Facility of National Central University (the institution of PI Wang), followed by logistic regression analysis on the data obtained. As other geotechnical studies, we utilize a geotechnical centrifuge to create our prototype model that is representative (or big) enough to reduce the scale effect in the geotechnical physical modeling.The methodology for Part II, assessing soil liquefaction probability in Taipei subject to the scenario of the Shanchiao fault inducing a major earthquake, is basically following the framework of seismic hazard analysis, with a variety of input data from fault length and slip rate to ground motion prediction equations. After the scenario-based CAV5 is determined with the analysis, it will be substituted into the CAV5-based logistic model, developed in Part I, to evaluate soil liquefaction probability in Taipei metropolitan areas with such a new approach.The key contribution of the proposed research is as follows: i) the CAV5-based liquefaction assessment model completes the framework of CAV5-based liquefaction analysis, considering CAV5 is strongly correlated with pore pressure buildup in soil, and ii) the application of the newly developed model to soil liquefaction investigation in Taipei can provide more insights to liquefaction microzonation for the study area, from a different perspective than previous studies based on conventional procedures. To help comprehend the key aspects of the proposal, a graphical executive summary was prepared and shown in Fig. 4 of the proposal. Please refer to it for a quick overview of the proposed research.