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）奖将探索将来自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，有弹性和可持续的生物胶结复合材料，用于改善软弱和有问题的土壤。虽然生物胶结已被证明可以显着改善土壤工程行为，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级生物复合材料相关的结构和机制中汲取灵感，以修改现有的生物胶结作用，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，长期弹性和岩土土壤改良和依赖民用基础设施的多功能性方面提供变革性效益。项目教育和外联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高等教育的关键缺陷：（1）通过在包括西雅图水族馆在内的各种场所进行宣传，提高代表性不足的少数民族学生对STEM领域，高等教育和职业的认识，（2）通过模块改善代表性不足的少数民族学生对STEM高等教育的招聘，移动的外展工具包，K-12教师学院，以及在课堂上实施内容，以及（3）通过研究经验，与支持计划相结合，以及将项目成果纳入课程，提高代表性不足的少数民族学生在STEM中的保留率。每年将有600多名K-12和社区大学的学生来自偏远和多样化的学生群体。项目研究将利用小规模地球化学实验，反应运输数值模拟，三轴和共振柱岩土实验室测试，以及先进的化学，生物和材料分析：（1）探索将生物启发原理转化为生物胶结土壤的潜力，以获得具有增强的断裂韧性、延展性和强度的生物胶结复合材料，（2）研究了生物胶结复合材料处理土的工程特性，包括（a）屈服前、屈服后和临界状态特性，（B）低应变动力特性，（c）液化特性，（3）检查生物胶结复合材料提供新功能的能力，包括污染物去除和热和水力增强，和（4）探索生物胶结复合材料对生物化学和机械应力的恢复力以及复合材料相对于现有技术的环境和经济效益。该项目将通过利用新的生物介导过程和生物启发原理来开发用于岩土工程地基改良的新材料，从而推进生物介导土壤改良的新兴领域，这些材料可以提高弹性，可持续性，该奖项反映了NSF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进行评估，被认为值得支持的搜索.

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.