Earthquake Induced Soil Liquefaction: Influence of Temperature and Dissolved Gas

地震引起的土壤液化：温度和溶解气体的影响P.I.：韦恩教授A.查理，博士，体育，土木工程系，科罗拉多州立大学研究摘要本研究的目的是确定温度和溶解气体如何影响1）地震诱导液化的最大距离、严重程度和时间，以及2）诱导液化的循环应力比CSR。 这项研究将包括详细的文献检索，统计分析，实验室测试程序和理论建模，以确定温度和溶解气体对地震诱导液化和液化桑迪后触发响应的影响。液化层上方经常发生地面开裂、地面沉降、侧向扩展和地基破坏。 一些研究人员已经使用了大量的液化案例和实验室试验，以1）预测距断层带的距离上限，2）CSR诱导液化。 然而，文献中报道的研究都没有将地面温度作为变量。大多数液化的实验室研究都是在室温（约20摄氏度）下进行的，而据报道，地震引起的液化发生在估计地面温度低至约2摄氏度（阿拉斯加）至高达27摄氏度（印度，委内瑞拉和墨西哥）的地方。 已知液态水的若干物理性质在此温度范围内变化。 P.I.进行的统计分析有限。对全球50多个地震的研究表明，温暖地区报告的液化最大距离是较冷地区报告的距离的两到三倍。 文献还表明，地震引起的液化会产生更高和更有活力的砂和水冲击，更大的砂吹火山口，以及在温暖气候中比在凉爽气候中大量逸出的气体。 更广泛的影响：该研究旨在通过将地温和溶解气体作为变量来增加对液化的科学理解，并改进当前岩土工程液化分析和预测的最新技术。 其结果将有助于公共安全，提高工程设计和建设的经济性，并教育学生在地震研究和分析。 这些结果也可能影响地震学家进行的地震学研究（一个不同的研究领域），他们调查使用古液化进行地震风险研究和工程研究的横向扩展和相关的桩基侧压力。 研究结果的发表可能会引发大量的现场，实验室和离心机测试和理论建模，以更好地了解这些影响。 该提案将培训地震工程领域的研究生，并鼓励本科生和代表性不足的学生参加。智力优点：在评价液化时考虑了许多参数，但温度或溶解气体不在其中。 私家侦探的初步分析。这表明，在其他条件相同的情况下，液化在温暖的气候中可能更普遍。正因为如此，温度依赖性的想法是值得追求的知识价值，以了解该过程，并从经济和公共安全的立场。

Earthquake Induced Soil Liquefaction: Influence of Temperature and Dissolved GasP.I.: Professor Wayne A. Charlie, PhD, PE, Civil Eng. Dept., Colorado State UniversityRESEARCH ABSTRACT The objectives of this research are to determine how temperature and dissolved gas influence 1) the maximum distance, severity, and timing of earthquake-induced liquefaction, and 2) the cyclic stress ratio, CSR, inducing liquefaction. The research will include a detailed literature search, statistical analysis, laboratory testing program, and theoretical modeling to determine the influence of temperature and dissolved gases on earthquake-induced liquefaction and post-triggering response of liquefied sandy soil. Ground cracking, ground settlement, lateral spreads and foundation failures commonly occur above liquefied layers. Several investigators have used extensive case histories of liquefaction and laboratory tests to 1) predict upper limits of distance from the zone of faulting, and 2) the CSR inducing liquefaction. However, none of the studies reported in the literature has included ground temperature as a variable. Most laboratory studies of liquefaction have been conducted at room temperature (about 20 degrees C) while earthquake-induced liquefaction has been reported where estimated ground temperatures are as low as about 2 degrees C (Alaska) to as high as 27 degrees C (India, Venezuela and Mexico). Several physical properties of liquid water are known to vary over this temperature range. Limited statistical analysis conducted by the P.I. on over 50 worldwide earthquakes indicates that warmer regions have maximum distances of reported liquefaction two to three times the distances reported in cooler regions. The literature also suggests that earthquake-induced liquefaction produces sand and water blows which are much higher and more energetic, larger sand blow craters, and gases which escapes in larger quantities in warmer climates than in cooler climates. Broader Impacts: The research is designed to increase the scientific understanding of liquefaction and to improve the current Geotechnical Engineering state-of-the-art of liquefaction analysis and prediction by including ground temperature and dissolved gas as variables. The results should contribute to public safety, improvement in economy of engineering design and construction, and educate students in earthquake research and analysis. The results may also impact seismological studies conducted by seismologists (a different field of research) who investigate the use of paleoliquefaction for seismic risk studies and engineering studies of lateral spread and associated lateral pressures on pile foundations. Publication of the research results may trigger substantial field, lab, and centrifuge testing and theoretical modeling to better understand these effects. The proposal will train graduate students in the area of earthquake engineering and undergraduate and underrepresented students will be encouraged to participate. Intellectual Merit: Many parameters have been considered in evaluating liquefaction, but temperature or dissolved gas have not been among them. Preliminary analysis by the P.I. suggests that, other things being equal, liquefaction may be more widespread in warmer climes. Because of this, the idea of temperature dependence is worth pursuing both from an intellectual merit to understand the process and from economic and public safety standpoints.