Evaluation and Mitigation of Membrane Compliance Effects in Soil Liquefaction Testing

土壤液化测试中膜柔顺效应的评估和缓解

• 批准号: 8711904
• 负责人: Raymond Seed
• 金额: $ 13.21万
• 依托单位: University of California-Berkeley
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-05-01 至 1990-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8711904&HistoricalAwards=false
• 关键词: Evaluation; Mitigation; Membrane; Compliance; Effects

Liquefaction, a potentially destructive type of ground failure, is commonly associated with fine-grained soils. Yet evidence exists that liquefaction occurred in coarse-grained soils such as gravels in the following earthquakes: Fukui (1948), Japan; Alaska (1964); Tangshan (1976), China; Mt. Borah (1984), Idaho. In spite of this evidence, liquefaction in gravelly soils has never been observed in laboratory tests. Presumably, this is due in some way to the failure of laboratory tests to reproduce the in-situ performance of gravelly soils. The most probable reason for this failure is the "membrane compliance effect." Soil samples must be held within a compliant rubber membrane when loaded mechanically in laboratory tests. Due to its compliance, the membrane is able to penetrate into the surface voids between grains, and this penetration increases with the coarseness of the soil particles. The objective of this research program is to develop improved laboratory testing procedures to eliminate this membrane compliance effect in liquefaction testing. The P.I. is a young investigator with an outstanding track record. He has the facilities available to accomplish the research proposed. The liquefaction of gravels is of serious economic consequence for various large construction projects because decisions have to be made as to the necessity of remedial work: the liquefaction potential of gravelly soils was not recognized when these projects were designed and constructed. It is recommended that this request for support be approved.

液化是一种潜在的破坏性地面破坏类型， 通常与细粒土壤有关。 然而，有证据表明， 液化发生在粗粒土，如砾石在 以下地震：日本福井（1948年）;阿拉斯加（1964年）;唐山 （1976），中国; Mt. Borah（1984），爱达荷州。 尽管有这些证据， 碎石土的液化在实验室中从未观察到过 试验. 据推测，这在某种程度上是由于实验室的失败， 试验，以再现碎石土的现场性能。 最 这种失败的可能原因是“膜顺应性效应”。" 土壤样品在加载时必须保持在一个顺应性的橡胶膜内 机械实验室测试 由于其顺应性，膜 能够渗透到颗粒之间的表面空隙中， 渗透性随着土壤颗粒的粗糙度而增加。 该研究计划的目标是开发改进的实验室 测试程序，以消除这种膜顺应性的影响， 液化试验 私家侦探是一个有着出色记录的年轻调查员 他 是否具备完成所提议研究的设施。 砾石的液化具有严重的经济后果， 各种大型建设项目，因为必须作出决定， 补救工作的必要性： 在设计这些项目时，砾石土没有得到承认， 构建了 建议核准这一支助请求。