CAREER: Extending Non-Destructive Infrastructure Assessment Techniques to Micropile Foundations

9875066职业生涯：将非破坏性基础设施评估技术扩展到微桩基础Sarah L. Gassman摘要：该职业奖旨在研究民用基础设施系统无损评估（NDE）的综合研究和教育方法。美国的许多民用基础设施由于老化、对适当维护的投资不足以及系统需求的增加而正在恶化。 NDE可以提供快速可靠的评估技术，用于处理大量不断恶化的民用系统，特别是桥梁，如果它们失败，将对安全构成严重威胁。 本研究的重点是开发一种基于应力波原理的无损检测技术，以有效和准确地评估微型桩基础的完整性，用于支持老化桥梁和建筑物的现有基础在修复过程中。本工作包括：1）使用表面和嵌入式传感器的纵波和弯曲波方法组合的微型桩基础的实验室调查，2）与信号处理和数值模拟相关的分析研究，3）原位微型桩的现场调查。虽然NDE是完善的，并通过钻孔桩和打入混凝土桩的大量现场经验证实，该技术是不确定的细长桩与高的长径比和桩的横截面尺寸有多个变化。 因此，本文将研究细长微型桩基础与周围土体之间的基本关系、截面积的多次变化对波的传播和接收信号的影响，以及用于微型桩施工的混凝土的频散效应。 一项教育计划与拟议的研究相结合，将基础设施评估、修复和监测技术纳入南卡罗来纳州大学的土木工程课程。 在基础设施故障、检查和修复方面，教育是至关重要的，以便让学生和工程人员掌握振兴和重建我国民用基础设施的技能。此外，该计划建议将NDE研究方法融入课程工作，为本科生提供更多的研究机会，并增加传统上代表性不足的群体的参与

9875066CAREER: Extending Non-Destructive Infrastructure Assessment Techniques to Micropile FoundationsSarah L. GassmanABSTRACT:This CAREER award investigates an integrated approach to research andeducation in non-destructive evaluation (NDE) of civil infrastructuresystems. Much of the civil infrastructure in the United States isdeteriorating due to age, inadequate investment in proper maintenance, andincreased system demand. NDE can provide fast and reliable assessmenttechniques that are needed to handle the large volume of deteriorating civilsystems, particularly bridges, that pose serious threats to safety if theyfail. The focus of this research is to develop a NDE technique based onstress wave principles to efficiently and accurately assess the integrity ofmicropile foundations that are used to support existing foundations of agingbridges and buildings during rehabilitation. This work consists of 1)laboratory investigations on micropile foundations using a combination oflongitudinal and flexural wave methods with surface and embedded sensors, 2)analytical studies related to signal processing and numerical simulation,and 3) field investigations of in situ micropiles. Although NDE is wellestablished and confirmed by extensive site experience for drilled shaftsand driven concrete piles, the technique is uncertain for slender piles withhigh length-to-diameter ratios and piles with multiple changes incross-sectional dimensions. Thus, this work will study the fundamentalrelationship between slender micropile foundations and the surrounding soil,the effect of multiple changes in cross-sectional area on wave propagationand the received signals, and the dispersive effects of the concrete usedfor micropile construction. An education plan is integrated with theproposed research to incorporate infrastructure assessment, rehabilitation,and monitoring technologies into the civil engineering curriculum at theUniversity of South Carolina. Education is critically needed in the areasof infrastructure failure, inspection, and rehabilitation to give bothstudents and the engineering workforce the skills to revitalize and preserveour nation's civil infrastructure. Furthermore, the plan proposes tointegrate NDE research methodology into course work, provide increasedresearch opportunities for undergraduates, and increase participation oftraditionally under-represented groups