Rheometrical techniques for the characterization of clay based suspensions relevant to geotechnical engineering

用于表征与岩土工程相关的粘土基悬浮液的流变技术

• 批准号: 0301729
• 负责人: Maria Caterina Santagata
• 金额: $ 7.84万
• 依托单位: Purdue University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-05-01 至 2006-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0301729&HistoricalAwards=false
• 关键词: Rheometrical; techniques; characterization; clay; based

Investigation of the rheological behavior of clay-water suspensions is important in many civil engineering problems. These materials are both present in nature, for example in mudflows, and are employed by man, appropriately engineered in some cases through the addition of additives (e.g. polymers, cement), in a variety of applications (as drilling and lubricating fluids in microtunneling and pipejacking, as grouts for soil improvement, as stabilizing fluids in tunnels and excavations, etc.). To date, investigations of these materials have been quite isolated by application and have often relied on empirical tests and on behavioral assumptions. The proposed research intends to explore the use of advanced rheometrical techniques for the rheological characterization of "engineered" clay-based suspensions employed in geotechnical applications. For this investigation use will be made of state of the art rheometers capable of performing viscosity, creep and oscillatory tests, which allow characterization of both the flow and the visco-elastic properties of these materials, and provide insight into their microstructure, in a manner so far never employed in geotechnical engineering. These properties will be investigated for different "systems": plain bentonite - water suspensions (base case), suspensions enhanced with three types of additives (one binder and two polymeric products), and suspensions prepared from commercially available products widely used in the drilling industry. These "systems", which pertain to different applications in geotechnical engineering, have different "performance" requirements and thus have the potential to illustrate the wide range in rheological behavior that can be observed.More traditional measurements (e.g. rheological measurements with traditional viscometers and pressure filtration tests) will also be performed to provide a link between fundamental behavior and properties used in practice for design and evaluation of fluids employed in geotechnical construction and to lay the basis for a more performance based design of these materials. In terms of broader impact the contributions of the study can be summarized in the following main points:- The proposed research will tackle the problem of engineered clay based suspensions with an interdisciplinary approach drawing on the methods and knowledge developed in other disciplines, such as fluid mechanics and soil science. With this approach, methods of testing and analysis previously not employed in geotechnical engineering will be applied to geotechnical "materials". Utilization in education of the experimental and analytical methods developed will contribute to innovate (graduate) teaching of experimental soil mechanics.- Collaboration with industry at the forefront in designing and manufacturing clay based materials for use in geotechnical applications will ensure that the research performed contributes to the solution of problems of practical significance, and will facilitate short term transfer of the fundamental lessons learned to the practical realm.- The agreement of collaboration with the Technical University of Torino in Italy will lay the basis for developing a continuous international partnership with one of the most renowned technical institution in Italy, and will promote broader dissemination of the work. - As a result of the above the project will provide unique development opportunities for the students involved in the research.

粘土-水悬浮体流变特性的研究在许多土木工程问题中具有重要意义。 这些材料既存在于自然界中，例如在泥石流中，也被人类使用，在某些情况下通过添加添加剂（例如聚合物、水泥）进行适当的工程设计，用于各种应用中（作为微型隧道和顶管中的钻井和润滑液，作为土壤改良的灌浆，作为隧道和挖掘中的稳定液等）。 到目前为止，这些材料的调查已经相当孤立的应用，往往依赖于经验测试和行为假设。拟议的研究旨在探索使用先进的流变技术的流变特性的“工程”粘土为基础的悬浮液在岩土工程应用。 对于这项调查，将使用最先进的流变仪能够进行粘度，蠕变和振荡测试，这使得这些材料的流动和粘弹性特性的表征，并提供深入了解其微观结构，到目前为止从未在岩土工程中使用的方式。这些属性将被调查为不同的“系统”：普通膨润土-水悬浮液（基本情况），悬浮液增强与三种类型的添加剂（一种粘合剂和两种聚合物产品），和悬浮液制备的商业产品广泛用于钻井行业。 这些“系统”，属于岩土工程中的不同应用，不同的“性能”要求，因此有可能说明可以观察到的流变行为的广泛范围。（例如，使用传统粘度计和压滤试验进行流变测量）还将进行，以提供基本行为和性能之间的联系，在实践中使用的设计和评估的流体在岩土工程建设，并奠定了基础，这些材料的设计。在更广泛的影响方面，这项研究的贡献可以概括为以下几个要点：-拟议的研究将利用其他学科（如流体力学和土壤科学）开发的方法和知识，以跨学科的方法解决工程粘土悬浮液的问题。 通过这种方法，以前在岩土工程中没有采用的测试和分析方法将应用于岩土“材料”。 开发的实验和分析方法在教育中的利用将有助于实验土力学的创新（研究生）教学。在设计和制造用于岩土工程应用的粘土基材料方面与行业的最前沿合作将确保所进行的研究有助于解决具有实际意义的问题，并将促进将学到的基本经验教训短期转移到实践领域。与意大利都灵技术大学的合作协议将为与意大利最著名的技术机构之一发展持续的国际伙伴关系奠定基础，并将促进更广泛地传播这项工作。 - 由于上述原因，该项目将为参与研究的学生提供独特的发展机会。