CAREER: A Direct In Situ Approach for Evaluating Liquefaction Characteristics of Soil Deposits

这项职业研究涉及开发现场技术，可以直接评估近地表沉积物的液化特征，距离地表5至10米。利用这些技术将有可能更准确和可靠地确定液化潜力，并且将通过各种现场调查提高有关液化的知识水平。要进行的研究需要开发一种液化评估试验，该试验在测量诱发应变和超孔隙水压力的同时对土壤进行动态加载。与现有的基于经验的液化评估技术相比，该测试技术将提供更多关于土壤沉积物液化潜力和孔隙压力产生特征的信息。利用内嵌式孔压传感器，研究了振动过程中及震动后孔隙水压力的产生、迁移和消散。来自现场孔压传感器的数据，以及孔压产生现象的数值模拟，将为各种孔压产生模型提供验证。这种原位测试技术可以更准确地评估土壤沉积物的液化特征和液化潜力，对土壤沉积物的孔隙压力生成特征进行原位评估，提高对液化的认识水平。作为这个项目的一个组成部分，工科学生将通过在课堂上使用工程案例来为技术和非技术问题做好准备。工程案例是对实际工程项目的书面描述。在本科和研究生阶段的工程课程中阅读和讨论相关案例可以更好地为学生的工程职业生涯做好准备。

This Career research involves developing in situ techniques that can directly assess the liquefaction characteristics of near surface deposits, within 5 to 10 meters of the ground surface. More accurate and reliable determinations of liquefaction potential will be possible with these techniques and the state of knowledge regarding liquefaction will be advanced through various site investigations.The research to be undertaken entails developing a liquefaction evaluation test that dynamically loads the soil in situ while measuring the induced strains and excess pore water pressures. This testing technique will provide significantly more information regarding the liquefaction potential and pore pressure generation characteristics of a soil deposit than in currently possible with available empirically based liquefaction evaluation techniques. Pore water pressure generation, migration, and dissipation during and after the induced shaking will be studied with embedded pore pressure transducers. Data from pore pressure transducers in the field, along with numerical modeling of the pore pressure generation phenomena, will provide validation of various pore pressure generation models. This is situ testing technique will allow the liquefaction characteristics and liquefaction potential of soil deposits to be assessed more accurately, the pore pressure generation characteristics of soil deposits to be evaluated in situ, and the state of knowledge regarding liquefaction to be advanced.As an integral part of this project, engineering students will be prepared for both technical and non-technical issues through the use of engineering cases in class-rooms. An engineering case is a written account of a real engineering project. Reading and discussing relevant cases in both undergraduate and graduate level engineering courses can better prepare students for engineering careers.