Workshop on Evaluation of Liquefation Resistane of Soils

摘要：CMS-9816185，Leslie Youd，Brigham Young U。在过去的二十五年里，一种被称为“简化程序”的程序已经发展起来，用于评估土壤的抗地震液化能力：它已经成为北美和世界大部分地区的实践标准。自那时以来，这一程序已得到定期更正和扩充。1985年，罗伯特·惠特曼教授代表国家研究委员会(NRC)在麻省理工学院召开了一次研讨会，36名专家和观察员在会上彻底审查了液化危险评估的知识和最新水平。该研讨会编写了一份报告(NRC，1985)，该报告已成为液化危险评估的广泛使用的标准和参考。在1985年的研讨会之后，直到1996年1月召开了一次研讨会，才对简化程序进行了全面审查或更新。在那次会议上，20名专家审查了自1985年以来的事态发展，以便就可建议用于工程实践的改进措施达成共识。会议记录由赞助商国家地震工程研究中心作为技术报告NCEER 97-0022发布。就几项(但不是全部)提出的改进最先进技术的建议达成了共识。例如，基于圆锥贯入试验(CPT)数据的液化抵抗程序得到了研讨会的几个关键成员的认可，但不是所有成员。这一工具在岩土工程实践中被广泛使用，迫切需要关于CPT方法的研讨会小组的协商一致声明。在这次研讨会之后，几位与会者测试了研讨会上讨论的CPT程序，所获得的结果被认为足以克服过去的关切。第二次会议的一个主要目标是评价这些额外的结果，并就CPT程序达成共识。可能加强建议的其他问题包括：细粒含量校正、震级比例系数和对高覆盖层压力的校正。重新召开的讲习班的目标是对总结报告进行协商一致的修订，并编写最后草稿，提交一份主要期刊，以便广泛传播给岩土工程专业人员。

ABSTRACT: CMS-9816185, Leslie Youd, Brigham Young U.Over the past twenty-five years, a procedure, termed the "simplified procedure", has evolved to evaluate the seismic liquefaction resistance of soils: it has become the standard of practice in North America and throughout much of the world. This procedure has been corrected and augmented periodically since then. In 1985, Professor Robert Whitman convened a workshop at MIT on behalf of the National Research Council (NRC), in which thirty-six experts and observers thoroughly reviewed the state-of-knowledge and the state-of-the-art for assessing the liquefaction hazard. That workshop produced a report (NRC, 1985) that has become a widely used standard and reference for liquefaction hazard assessment.No general review or update of the simplified procedures was made following the 1985 workshop until a workshop was convened in January 1996. At that meeting, twenty experts reviewed developments since 1985, in order to arrive at a consensus on improvements that could be recommended for engineering practice. The proceedings were published by the sponsor, the National Center For Earthquake Engineering Research, as Technical Report NCEER 97-0022. Consensus was achieved on several, but not all, proposed enhancements to the state of the art. For example, liquefaction resistance procedures based on cone penetration test (CPT) data were endorsed by several key members of the workshop, but not all. This tool is widely used in geotechnical engineering practice and a consensus statement from the workshop group on CPT methodologies is badly needed. Subsequent to this workshop, several of the participants tested the CPT procedures discussed at the workshop, and the results obtained are considered to be sufficient to overcome past concerns.A major goal of the second meeting is to evaluate these additional results, and to gain a consensus on CPT procedures. Additional issues where enhanced recommendations may be possible include: fines-content corrections, magnitude scaling factors, and correction for high overburden pressures. The objective of the reconvened workshop is to produce consensus revisions to the Summary Report, and to prepare a final draft for submission to a major journal for broad dissemination to the geotechnical engineering profession.