Experimental and Computational Investigation of Fracture Propagation in Rocks

彻底了解岩石裂隙为什么、何时、何地开始、扩展和融合，对于斜坡、基础和隧道等岩石结构的稳定性以及涉及爆破和水力破裂的过程至关重要。该项目将包括对岩石样品的断裂进行先进的实验室测试，这些测试将提供材料行为的数据，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，从而在广泛的应用领域造福社会。这项研究将与教育和外联活动相结合。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这一项目，例如通过CSM校园内的女工程师协会(SWE)和多元文化工程计划(MEP)学生组织。他们还将开发、实施和评估将在研讨会期间提供的材料行为教学动手模块。研究成果将被纳入研究生和本科课程，并通过会议和期刊文章传播。本研究项目的目的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征。研究的目的是建立新的实验验证的裂纹萌生和扩展准则，该准则可以应用于具有不同缺陷几何形状的不同岩石，以便在高级数值程序中实施。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-数值相结合的研究。将对花岗岩、石灰岩和有预先存在缺陷的砂岩进行一套全面的单轴压缩实验，结合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，新的裂缝起裂准则将被开发并在扩展有限元程序中实施，以提供一种全新的、具有潜在变革性的数值工具，用于评价和预测各向异性岩层中的裂缝。

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.