{"title":"Effects of crystal orientation, temperature, deviatoric stress, and confining stress on creep of rock salt","authors":"","doi":"10.1016/j.ijrmms.2024.105913","DOIUrl":null,"url":null,"abstract":"<div><div>The creep of rock salt greatly influences the performance and safety of rock salt caverns when they are used as an underground repository for oil, nuclear waste, or other hazardous materials. Creep may cause shearing of casings of oil wells drilled through thick layers of salt rock formation. The crystallographic structure of salt rock grains, in-situ deviatoric stress changes caused by excavation, confining stress from the surrounding environment, and ambient temperature can have a significant impact on the creep behavior of rock salt. Although the creep behavior of polycrystalline rock salt has been extensively studied by many researchers, the creep behavior of single-crystal natural rock salt is not yet fully understood. This paper investigates the influence of crystal orientation, temperature, deviatoric stress, and confining stress on the creep behavior of single-crystal and polycrystalline rock salt. 42 long-term creep experiments with various temperatures, confining stresses, and deviatoric stresses were conducted on natural single-crystal specimens. The temperatures were 20, 100, and 150 °C, the confining stresses were 0.1, 1.0, and 5.0 MPa, and the various deviatoric stresses were applied in different loading directions with respect to the specimen's crystal orientations. Additionally, 18 long-term creep experiments were performed on synthetic polycrystalline specimens with wet grain boundaries at temperatures of 20, 100, and 150 °C, at confining stresses of 0.1, 1.0, and 5.0 MPa, and various deviatoric stresses. The effects of the mentioned experimental conditions on the accumulated axial strain, transient strain rate, and steady-state strain rate during the creep of rock salt were then examined and discussed in detail. Moreover, the influence of temperature, deviatoric stress, and confining stress on the steady-state creep of single crystal rock salt is examined within the context of existing polycrystalline creep data available in the literature.</div></div>","PeriodicalId":54941,"journal":{"name":"International Journal of Rock Mechanics and Mining Sciences","volume":null,"pages":null},"PeriodicalIF":7.0000,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"International Journal of Rock Mechanics and Mining Sciences","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1365160924002788","RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, GEOLOGICAL","Score":null,"Total":0}
引用次数: 0
Abstract
The creep of rock salt greatly influences the performance and safety of rock salt caverns when they are used as an underground repository for oil, nuclear waste, or other hazardous materials. Creep may cause shearing of casings of oil wells drilled through thick layers of salt rock formation. The crystallographic structure of salt rock grains, in-situ deviatoric stress changes caused by excavation, confining stress from the surrounding environment, and ambient temperature can have a significant impact on the creep behavior of rock salt. Although the creep behavior of polycrystalline rock salt has been extensively studied by many researchers, the creep behavior of single-crystal natural rock salt is not yet fully understood. This paper investigates the influence of crystal orientation, temperature, deviatoric stress, and confining stress on the creep behavior of single-crystal and polycrystalline rock salt. 42 long-term creep experiments with various temperatures, confining stresses, and deviatoric stresses were conducted on natural single-crystal specimens. The temperatures were 20, 100, and 150 °C, the confining stresses were 0.1, 1.0, and 5.0 MPa, and the various deviatoric stresses were applied in different loading directions with respect to the specimen's crystal orientations. Additionally, 18 long-term creep experiments were performed on synthetic polycrystalline specimens with wet grain boundaries at temperatures of 20, 100, and 150 °C, at confining stresses of 0.1, 1.0, and 5.0 MPa, and various deviatoric stresses. The effects of the mentioned experimental conditions on the accumulated axial strain, transient strain rate, and steady-state strain rate during the creep of rock salt were then examined and discussed in detail. Moreover, the influence of temperature, deviatoric stress, and confining stress on the steady-state creep of single crystal rock salt is examined within the context of existing polycrystalline creep data available in the literature.
期刊介绍:
The International Journal of Rock Mechanics and Mining Sciences focuses on original research, new developments, site measurements, and case studies within the fields of rock mechanics and rock engineering. Serving as an international platform, it showcases high-quality papers addressing rock mechanics and the application of its principles and techniques in mining and civil engineering projects situated on or within rock masses. These projects encompass a wide range, including slopes, open-pit mines, quarries, shafts, tunnels, caverns, underground mines, metro systems, dams, hydro-electric stations, geothermal energy, petroleum engineering, and radioactive waste disposal. The journal welcomes submissions on various topics, with particular interest in theoretical advancements, analytical and numerical methods, rock testing, site investigation, and case studies.