CAREER: Mollusk and Arthropod-inspired Bio-Cemented Composites for Sustainable, Resilient, and Multifunctional Ground Improvement

该学院早期职业发展（Career）奖将探索将软体动物和节肢动物中发现的天然复合材料的生物启发原理与现有的生物胶结土壤改良相结合的潜力，以产生多功能，弹性和可持续的生物胶结复合材料，以改善脆弱和有问题的土壤。虽然生物胶结已被证明可以显著改善土壤工程行为，但胶结的存在也可能导致一些潜在的不利反应，包括快速的强度和刚度损失。该项目将从与机械上优越的生物复合材料相关的结构和机制中获得灵感，以修改现有的生物胶结，并进一步增强土壤工程行为，从而在环境可持续性、经济效益、长期弹性和岩土土改良的多功能性和依赖的民用基础设施方面提供变革性效益。项目教育和外展活动将通过以下方式解决代表性不足的少数民族学生接受stem高等教育的严重缺陷：(1)通过包括西雅图水族馆在内的各种场所的外展，提高未被充分代表的少数族裔学生对STEM领域、高等教育和职业的认识；(2)通过模块、移动外展工具包、K-12教师学院和课堂内容的实施，改善未被充分代表的少数族裔学生在STEM高等教育中的招聘情况；(3)通过研究经验提高未被充分代表的少数族裔学生在STEM领域的保留率。与支持计划整合，并将项目成果纳入课程。每年将有600多名K-12和社区大学的学生参与其中，他们来自偏远和不同的学生群体。项目研究将利用小规模生物地球化学实验、反应性输运数值模拟、三轴和共振柱岩土工程实验室测试以及先进的化学、生物和材料分析，以便：(1)探索生物激励原理转化为生物胶结土的潜力，以实现具有增强断裂韧性、延性和强度的生物胶结复合材料；(2)研究生物胶结复合材料处理土的工程行为，包括(a)屈服前、屈服后和临界状态行为，(b)低应变动态特性，(c)液化行为；(3)研究生物胶结复合材料提供污染物去除、热和水力增强等新功能的能力；(4)探索生物胶结复合材料对生物地球化学和机械应力源的弹性，以及相对于现有技术的复合材料的环境和经济效益。该项目将通过利用新的生物介导过程和生物启发原理，开发用于岩土工程地基改善的新材料，从而推进生物介导土壤改善的新兴领域，从而提高民用基础设施的弹性、可持续性和多功能性。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This Faculty Early Career Development (CAREER) award will explore the potential for incorporating bio-inspired principles from natural composites found in mollusks and arthropods with existing bio-cementation soil improvement to yield multifunctional, resilient, and sustainable bio-cemented composites for the improvement of weak and problematic soils. While bio-cementation has been shown to dramatically improve soil engineering behaviors, the presence of cementation can also result in some potentially unfavorable responses including rapid strength and stiffness losses. This project will draw inspiration from the structure and mechanisms associated with mechanically superior biogenic composites to modify existing bio-cementation and further enhance soil engineering behaviors to provide transformative benefits with respect to the environmental sustainability, economic efficacy, long-term resilience, and multifunctionality of geotechnical soil improvement and reliant civil infrastructure. Project education and outreach activities will address critical deficiencies in the pipeline of underrepresented minority students towards STEM-based higher education by: (1) increasing the awareness of underrepresented minority students of STEM fields, higher education, and careers through outreach at various venues including the Seattle Aquarium, (2) improving the recruitment of underrepresented minority students to STEM-based higher education through modules, mobile outreach toolkits, an academy for K-12 teachers, and implementation of content in classrooms, and (3) enhancing underrepresented minority student retention in STEM through research experiences, integration with support programs, and incorporation of project outcomes in curricula. Over 600 K-12 and community college students will be engaged annually from remote and diverse student populations. Project research will leverage small-scale biogeochemical experiments, reactive transport numerical modeling, triaxial and resonant column geotechnical laboratory tests, and advanced chemical, biological, and material analyses to: (1) explore the potential of bio-inspired principles to be translated to bio-cemented soils to achieve bio-cemented composites with enhanced fracture toughness, ductility, and strength, (2) investigate the engineering behaviors of bio-cemented composite treated soils including (a) pre-yielding, post-yielding, and critical state behaviors, (b) low-strain dynamic properties, and (c) liquefaction behaviors, (3) examine the ability of bio-cemented composites to provide new functionalities including contaminant removal and thermal and hydraulic enhancements, and (4) explore the resilience of bio-cemented composites to biogeochemical and mechanical stressors and the environmental and economic efficacy of composites relative to existing technologies. The project will advance the emerging field of bio-mediated soil improvement by leveraging novel bio-mediated processes and bio-inspired principles to develop new materials for geotechnical ground improvement that can improve the resiliency, sustainability, and multifunctionality of civil infrastructure.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.