CAREER: Linking Rheology to Performance - An Integrated Approach to the Evaluation and Design of Trenchless Technology Fluids

摘要：本研究探讨了非开挖技术（微隧道、顶管和水平定向钻井）中流体的设计和评估。这些流体在地下公用设施的建设和修复中起着至关重要的作用，仅在美国，地下公用设施的总长度估计就超过3500万英里。仅水和废水的延期维护成本每年就超过1000亿美元，因此，能够扩大建设和修复资金覆盖范围的技术具有重大价值。所有非开挖技术的成功至关重要的是使用具有四个关键功能的流体：润滑；滤饼形成及过滤控制；破坏/削减运输;还有土壤调理。为了优化这些流体的选择/设计，必须以综合的方式同时考虑所有这些方面的性能。本研究的重点是开发一种综合方法来设计和评估非开挖技术中使用的流体。这项工作是建立在使用最先进的设备和方法对各种流体流变特性进行基本调查的基础上的。研究的重点主要是基于膨润土的流体，无论是纯的还是纯的。以及用化合物（不同类型的聚合物、表面活性剂、蜡、微珠）处理以增强其性能。然而，在次要基础上选择聚合物流体也将进行研究。结合流变学测试，实验方案包括旨在评估流体在所描述的四种主要功能中的性能的实验，在代表现场发生的条件下，与流变学数据直接相关。通过最先进的带冷冻装置的扫描电镜设备对水合状态下流体的微观结构进行观察，将提供将观察到的行为与微观结构联系起来的手段。教育活动与研究直接相关，旨在使包括K-12学生和大学新生在内的广大受众受益。特别是，研究将看到一个本科生团队直接参与，通过参与一个创新的设计为基础的课程，以支持研究活动。该提案包含一项计划，旨在招募妇女和代表性不足的少数民族从事土木工程，并增加她们对研究的参与。

Abstract:This research addresses the topic of the design and evaluation of fluids employed in trenchless technology (microtunneling, pipejacking, and horizontal directional drilling). These fluids play a critical role in the construction and rehabilitation of underground utility infrastructures, the total length of which is estimated to exceed 35 million miles in the US alone. With deferred maintenance costs for water and wastewater alone assessed at more than $100 Billion/year, techniques that can extend the reach of the construction and rehabilitation dollar have significant value. Paramount to the success of all trenchless technologies is the use of a fluid which serves four critical functions: lubrication; cake formation and filtration control; spoil/cutting transport; and soil conditioning. For optimal selection/design of these fluids all these aspects of performance must be considered simultaneously in an integrated manner. The focus of this research is to develop an integrated approach to the design and evaluation of fluids used in trenchless technology. The work is founded on a fundamental investigation of the rheological properties of a variety of fluids performed using state-of-the-art equipment and methodologies. The emphasis of the research is primarily on bentonite based fluids, both ?pure? as well as treated with the compounds (polymers of different types, surfactants, waxes, micro-beads) that are used to enhance their properties. However, on a secondary basis select polymeric fluids will also be investigated. In conjunction with the rheological tests, the experimental program includes experiments designed to evaluate the performance of the fluids in the four primary functions described, under conditions representative of those occurring in the field, for direct correlation to the rheological data. Microstructural observations of the fluids in their hydrated state through state of the art SEM equipment with cryo-unit, will provide the means to link observed behavior to microstructure.The educational activities have a direct tie to the research and are designed to benefit a large audience including K-12 students and college freshmen. In particular, the research will see the direct involvement of a team of undergraduate students in support of the research activities through participation in an innovative design based course. The proposal contains a plan for recruiting women and underrepresented minorities to civil engineering and increasing their involvement in research.