Swelling Rock Swelling Characteristics Of Fractal Research And Testing Research

Swelling rock, formed in natural geologic processes and composed of a great deal of strong hydrophilic clay minerals, is of remarkable shrink-swell properties. The volume of swelling rock can expand when it absorbs water and shrink when it loses water. Thus, it can exert destructive pressure to buildings with long potential dangers. In this thesis, the swelling mechanism, the principal influential factors of rock swelling, the microscopic study method and the conventional swelling testing procedures have been discussed. The fractal theory has been introduced to study microscopic properties with the fractional dimension in expansive soils. The relation between fractional dimension and microscopic properties and macroscopic swelling properties has been carried out. The use of new lc~ oedometer JCY to study the properties of swelling rock is illustrated in this thesis.Based on the box dimension method, the fractional dimensions of expansive soils have been carried out using Auto-CAD technique. The relationship between fractional dimension and initial physical state is established. With use of the new oedometer, the swelling experiment for swelling rock sampled from the Nanjing Meishan Ferrous Mine have been conducted. Based on the experiment results, the relationship among the five variables, such as swelling strain, absorbed water content, radial stress, axial pressure and time, are analyzed in the paper. Then, Einstein-Wittke swelling constitutive relationship and the triaxial swelling test constitutive relationship are discussed. Finally, the review on the two oedometers, one is the 1c~ oedometer and the other was developed by Mr. Jiao Jiankui last year, has been given.