SGER: Development of Field Delivery System of Oxygen Bubbles for Seismic and Geoenvironmental Hazard Mitigation

SGER：开发用于减轻地震和地质环境灾害的氧气气泡现场输送系统

• 批准号: 0917750
• 负责人: M. K. Yegian
• 金额: --
• 依托单位: Northeastern University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-06-01 至 2010-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0917750&HistoricalAwards=false
• 关键词: SGER; Development; Field; Delivery; System

Mitigation of liquefaction-induced damages to the built environment continues to be an important priority and a major challenge in civil engineering. Current soil improvement methods to safeguard against liquefaction are often very expensive and their applications are limited to new sites. There is an urgent need to develop cost-effective liquefaction mitigation measures that can be applied to new sites as well as sites where structures exist. The PI and CO-PI have been conducting research on developing an innovative method for liquefaction mitigation based on inducing partial degree of saturation in otherwise fully saturated liquefiable sands. The research to date has demonstrated the technical feasibility of the method. Laboratory tests have led to the conclusion that introduction of gas bubbles in sand, thus reducing its degree of saturation, prevents the occurrence of liquefaction. While the feasibility of induced partial saturation as a potential liquefaction mitigation measure has been successfully demonstrated, it is the PI and CO-PI?s ultimate goal to further advance this mitigation measure, prove its feasibility through field research tests so that the professional engineering community considers its application in practice. This will require implementation of a comprehensive research program with testing under large scale laboratory and field conditions. However, such a research program can not be embarked nor funding can be secured unless two distinct and important research goals are first achieved. This SGER award focuses on these two research goals. The first goal of the proposed research is to devise a delivery system that can generate gas bubbles in fully saturated sands that can be implemented with high likelihood of success in the field. This gas delivery system should be practical and be able to reduce the degree of saturation of sands rapidly and uniformly. The second important goal is to devise a field testing technique that can be used to assess the effectiveness of the gas delivery system leading to validation of partial degree of saturation, as well as the uniformity of the site remediation. Results from preliminary investigations suggest that oxygen bubbles can be generated within sands through the introduction of chilled water with dissolved ?Efferdent? (primarily sodium perborate), or through chilled hydrogen peroxide with an added catalyst to release oxygen when temperature of the fluid rises. Also, it is apparent that the use of a piezocone and measurement of excess pore pressures developed during the penetration of the piezocone into the sand can be a practical and rapid way of validating partial degree of saturation and its uniformity. These exploratory research activities will be conducted using the SoilBed facility of the Center for Subsurface Sensing and Imaging Systems (NSF-ERC-CenSSIS) The outcome of this research can help advance efforts at developing a cost-effective liquefaction mitigation measure that can have world-wide impact on safety and protection of property from earthquake hazards. Development of cost-effective oxygen delivery system can also help in situ bioremediation method to be more widely implemented in practice. The research is collaboration between faculty and students in the fields of earthquake engineering and geoenvironmental engineering. Such interdisciplinary collaborations have led to innovative ideas and continue benefiting undergraduate and graduate students engaged in the research

缓解液化引起的对建筑环境的损害仍然是土木工程中的重要重中之重和重大挑战。 当前的土壤改进方法以保护液化通常非常昂贵，并且其应用仅限于新地点。 迫切需要开发具有成本效益的缓解液化措施，这些措施可以应用于新站点以及存在结构的站点。 PI和Co-Pi一直在进行研究基于诱导原本完全饱和液化砂的局部饱和度的创新方法缓解液化方法的研究。 迄今为止的研究证明了该方法的技术可行性。 实验室测试得出的结论是，在沙子中引入气泡，从而降低了其饱和度，从而阻止了液化的发生。 尽管已成功证明了诱发部分饱和作为潜在的缓解液化措施的可行性，但PI和Co-Pi的最终目标是进一步推进这种缓解措施，并通过现场研究测试证明了其可行性，以便专业工程社区在实践中考虑其应用。 这将需要在大规模实验室和现场条件下实施一项全面的研究计划。 但是，除非首先实现两个不同的重要研究目标，否则无法登陆此类研究计划，也无法确保资金。该SGER奖的重点是这两个研究目标。 拟议的研究的第一个目标是设计一个可以在完全饱和的沙子中产生气泡的输送系统，该沙子可以在该领域成功实施。 该气体输送系统应实用，并能够快速，均匀地降低沙子的饱和程度。第二个重要目标是设计一种现场测试技术，该技术可用于评估气体输送系统的有效性，从而验证部分饱和度以及现场修复的均匀性。初步研究的结果表明，通过引入溶解的冷水？ （主要是perborate钠），或通过添加催化剂的过氧化氢通过冰冻氢，当流体温度升高时释放氧气。 同样，很明显，使用压电和测量在压电中渗透到砂过程中产生的过量孔隙压力可能是验证部分饱和度及其均匀性的实用且快速的方法。 这些探索性研究活动将使用地下传感和成像系统中心（NSF-erc-Censsis）的土壤床设施进行，这项研究的结果可以帮助促进努力，以开发一种具有成本效益的缓解液化措施，该措施可能会对全球范围内对地震危害的财产安全和保护对财产的安全产生影响。 开发具有成本效益的氧气输送系统还可以帮助原位生物修复方法在实践中更广泛地实施。 这项研究是地震工程和地球环境工程领域的教师与学生之间的合作。 这种跨学科的合作导致了创新的想法，并继续使从事研究的本科生和研究生受益