Experimental and Computational Investigation of Fracture Propagation in Rocks

深入了解岩石裂缝产生、传播和合并的原因、时间和地点，对于边坡、地基和隧道等岩石结构的稳定性以及爆破和水力压裂过程至关重要。 该项目将涉及岩石样品断裂的先进实验室测试，这些测试将提供有关材料行为的数据，用于可用于预测能力的计算模型。 该项目的交付成果将使土木和岩土工程师能够进行更安全，更经济的设计，从而使社会在广泛的应用中受益。 这项研究将与教育和外联活动结合起来。 该项目的跨学科性质，包括实验岩石力学和计算地质力学，将为科罗拉多矿业学院（CSM）的本科生和研究生提供出色的教育和培训机会。 研究人员将鼓励代表性不足的群体参与该项目，例如通过CSM校园内的女工程师协会（SWE）和多元文化工程项目（MEP）学生组织。 他们 还将开发，实施和评估在研讨会期间提供的材料行为的教学实践模块。 研究结果将纳入研究生和本科生课程，并通过会议和期刊文章传播。该研究项目的目标是发现具有不同预先存在的缺陷几何形状的天然岩石的破裂特性。 研究的目标是制定新的实验验证的裂纹萌生和扩展的标准，可适用于不同的岩石与不同的缺陷几何形状，在先进的数值代码的实施。 该项目的一个关键创新是对天然岩石破裂过程的力学-地球物理-数值研究相结合。 将对具有预先存在的缺陷的花岗岩、石灰岩和砂岩进行一套全面的单轴压缩实验，协同使用声发射和主动地球物理（超声波）监测技术。 基于实验观察，将开发新的裂缝起裂准则，并在扩展有限元法（XFEM）代码中实施，以提供用于评估和预测各向异性岩层中的裂缝的全新且具有潜在变革性的数值工具。

A thorough understanding of why, when and where rock fractures initiate, propagate and coalesce is of critical importance in the stability of rock structures such as slopes, foundations, and tunnels, as well as processes involving blasting and hydraulic fracture. This project will involve advanced laboratory testing of fracture in rock samples that will provide data on material behavior for use in computational models that can be used in a predictive capacity. The deliverables of this project will allow civil and geotechnical engineers to perform safer and more economical designs that will benefit society across a broad range of applications. The research will be integrated with educational and outreach activities. The interdisciplinary nature of this project, including experimental rock mechanics and computational geomechanics, will provide outstanding educational and training opportunities for undergraduate and graduate students at the Colorado School of Mines (CSM). The researchers will encourage the participation of underrepresented groups on this project, e.g. through the Society of Women Engineers (SWE) and Multicultural Engineering Program (MEP) student organizations on the CSM campus. They will also develop, implement, and assess instructional hands-on modules on materials behavior to be delivered during workshops. The research findings will be incorporated into graduate and undergraduate courses and disseminated through conference and journal articles. The goal of this research project is to discover the fracturing characteristics of natural rocks with different pre-existing flaw geometries. The research objective is to formulate new experimentally verified crack initiation and propagation criteria that can be applied to different rocks with different flaw geometries for implementation in advanced numerical codes. A key innovation in this project is the combined mechanical-geophysical-numerical investigation of the fracturing processes in natural rocks. A comprehensive suite of uniaxial compression experiments will be conducted on granite, limestone, and sandstone with pre-existing flaws, with synergistic use of acoustic emission and active geophysical (ultrasonic) monitoring techniques. Based on experimental observations, new fracture initiation criteria will be developed and implemented in an eXtended Finite Element Method (XFEM) code to provide an entirely novel and potentially transformative numerical tool for assessment and prediction of fracturing in anisotropic rock formations.