Soil Liquefaction Hazard Assessment by the Vision Cone Penetrometer

本研究计划涉及使用新开发的视觉圆锥贯入仪（VisCPT）的地震液化危险性评估。 VisCPT本质上是一个标准的电子圆锥体比重计，通过包含两个微型CCD摄像机进行修改。 摄像机通过两个放大级别收集土壤地层学的连续视频图像流。 VisCPT可以描绘土壤地层，并通过各种计算机视觉技术，提供土壤的粒度分析。该项目的目标是在位于旧金山弗朗西斯科的国家岩土试验场（NGES）收集VisCPT数据，这些试验场位于细颗粒百分比可变的位置。 还采集了土壤物理样本。 所收集的VisCPT数据进行评估，具体侧重于确定粒度分布的图像纹理技术。 VisCPT图像还与标准CPT尖端电阻测量进行了比较，以说明和量化地层分层和界面对CPT读数的影响。

This research program addresses the use of a newly developed Vision Cone Penetrometer (VisCPT) for earthquake-induced liquefaction hazard assessment. The VisCPT is essentially a standard electronic cone penetrometer, modified by inclusion of two miniature CCD video cameras. The cameras collect a continuous stream of video images of the soil stratigraphy by two levels of magnification. The VisCPT can delineate soil stratigraphy, and through various computer vision techniques, provide a grain size analysis of the soil.The objective of this project is to collect VisCPT date at the National Geotechnical Experimentation Site (NGES) on Treasure Island in San Francisco, at locations with variable percentages of fine particles. Physical soil samples are also taken. The collected VisCPT data is evaluated with specific focus on image-texture techniques for determining grain size distributions. The VisCPT images are also compared to standard CPT tip resistance measurements in order to illustrate and quantify the effects of stratigraphic layering and interfaces on CPT readings.