RAPID/Collaborative Research: Liquefaction Mitigation of Silts using MIDP and Field Testing with NHERI UTexas Large Mobile Shakers

快速/协作研究：使用 MIDP 缓解淤泥液化并使用 NHERI UTexas 大型移动振动筛进行现场测试

• 批准号: 1935774
• 负责人: Kenneth Stokoe
• 金额: $ 4.88万
• 依托单位: University of Texas at Austin
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-07-01 至 2020-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1935774&HistoricalAwards=false
• 关键词: RAPID; Collaborative; Research; Liquefaction; Mitigation

The overall objective of this Grant for Rapid Response Research (RAPID) project is to evaluate the potential for a soil liquefaction mitigation technique in relatively fine-grained soils. This technique uses new advancements in the field of bio-remediation and will be tested in the field at a site located in Portland, Oregon. The project addresses a major seismic problem in Oregon, where many infrastructure facilities are founded on non-plastic to low-plasticity silts that are susceptible to liquefaction in a Magnitude 9 Cascadia Subduction Zone earthquake. The site selected for study are near the Critical Energy Infrastructure (CEI) hub located in northwest Portland, where 90 percent of the Oregon's liquid fuel and all jet fuels for Portland's airport are handled. The seismic vulnerability of fuel tanks at the CEI hub is a critical impediment to Oregon's resilience and energy reliability in the wake of a major earthquake. If the mitigation method in this project is proved to be effective in the field, it will provide a vertical step for adopting this solution for infrastructure founded on liquefiable silty soils. This will enhance the resiliency of Oregon after a major earthquake, and it can be adopted in other places with similar subsurface conditions.This project will evaluate the potential for microbially induced desaturation via dissimilatory reduction of nitrogen (denitrification) to mitigate liquefaction potential in relatively fine-grained soils. We hypothesize that 1) denitrification via two weeks of treatment can lower the degree of saturation to 80 percent in silty soils in the field, 2) this level of desaturation will eliminate pore water pressure generation in treated soils subjected to in-situ cyclic strains, and 3) the desaturation will persist for years due to the small pore size in silty soils (although this will need to be verified in subsequent research). Our approach to evaluate these hypotheses involves in-situ shaking using NHERI@UTexas field equipment at a site before and after treatment, and periodic monitoring of compression (P-) wave velocities during the next 3 to 5 years.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

这项对快速响应研究赠款（快速）项目的总体目标是评估相对细粒土壤中土壤液化缓解技术的潜力。该技术使用了生物修复领域的新进步，并将在俄勒冈州波特兰的一个地点进行测试。该项目解决了俄勒冈州的一个主要地震问题，其中许多基础设施建立在非塑料至低塑性淤泥上，这些淤泥在9级Cascadia俯冲区地震中容易受到液化的影响。选择进行研究的地点附近位于波特兰西北部的关键能源基础设施（CEI）枢纽，那里处理了俄勒冈州的90％的液体燃料和所有用于波特兰机场的喷气燃料。 CEI枢纽燃油箱的地震脆弱性是俄勒冈州发生重大地震后俄勒冈州的韧性和能量可靠性的关键障碍。如果事实证明该项目中的缓解方法在现场有效，则它将为在液化粉质土壤上建立的基础设施采用该解决方案提供垂直步骤。这将提高大地震后俄勒冈州的弹性，并且可以在其他具有相似地下条件的地方采用。该项目将评估微生物诱导的去饱和度的潜力，通过异化的氮（nitrification）降低，以减轻相对细化的土壤中的液化潜力。我们假设1）通过两周的治疗来硝化可以将饱和度降低至该领域的粉质土壤中的80％，2）这种去饱和水平将消除经过的原位环状菌株中处理的土壤中的孔隙水压产生，而在这种情况下，脱饱和度持续了数年，尽管在silty的土壤中逐渐验证了这一点（均需要验证的土壤中）。我们评估这些假设的方法涉及在治疗前后使用NHERI@UTEXAS现场设备在接下来的3到5年中对压缩（P-）波速进行定期监控的原位摇动。该奖项反映了NSF的立法任务，反映了通过基金会的智力综述和宽广的评估，并值得通过评估来进行评估。