|
|
Experimental study on strength and deformation characteristics of marble after creep |
CAI Yanyan1,2,SUN Qichao1,YU Jin1,2,LIU Shiyu1,CHEN Xu1,LIU Lipeng3 |
(1. Fujian Engineering Technology Research Center for Tunnel and Underground Space,Huaqiao University,Xiamen,Fujian 361021,China;2. State Key Laboratory for Geomechanics and Deep Underground Engineering,China University of Mining and Technology,Xuzhou,Jiangsu 221008,China;3. Department of Geotechnical Engineering,China Institute of Water Resources and Hydropower Research,Beijing 100048,China) |
|
|
Abstract In order to investigate the effect of creep behavior on the strength and deformation of rock,a number of marble samples were pretreated under different hours of creep preloading at different stress levels which contains the compaction stage,elastic stage,stable stage of crack growth,unstable crack growth and failure stage on the whole stress-strain curves. After the creep loading,the samples were reloaded under uniaxial compression to analyze the influence of creep behavior on the strength and deformation of marble. Meanwhile,a new method was proposed to divide the stages of volume strain using the volumetric strain rate. The creep at the stress levels of the compaction stage or the elastic stage enhances the mechanical performance of marble. With the creep time increases,the uniaxial strength and elastic modulus increase but Poisson’s ratio decreases. The enhanced degree of mechanical performance of creep is greater at the elastic stage than at the compaction stage. In addition,the failure of the rock samples occurs in a short time if the creep is conducted at the unstable crack growth or failure stage. The deformation process of the rock can be divided into three stages according to the dilatation rate,a stable compaction stage,an accelerated dilatation stage and a decelerated dilatation stage. After going through the creep preloading at the compaction stage or the elastic stage,the dilatation rates of marble samples decrease slightly with the increasing in creep time. On contrary,after going through the creep preloading at the stable crack growth stage,the dilatation rates increase dramatically with the creep time increases. The failure patterns of marble samples without creep preloading under uniaxial compression are mainly shear failure with a single macrocrack. With the increasing of the creep time,the failure patterns of marble samples underwent creep preloading at the compaction stage or the elastic stage were gradually transformed from shear failure to splitting failure. The failure patterns of marble samples underwent creep preloading at the stable crack growth gradually transform to the mixed mode of shear and splitting failures,accompanied by several principal cracks and numerous associated cracks.
|
|
|
|
|
[1] |
孙 钧. 岩石流变力学及其工程应用研究的若干进展[J]. 岩石力学与工程学报,2007,26(6):1 081-1 106.(SUN Jun. Rock rheological mechanics and its advance in engineering applications[J]. Chinese Journal of Rock Mechanics and Engineering,2007,26(6):1 081-1 106.(in Chinese))
|
[2] |
杨春和,白世伟,吴益民. 应力水平及加载路径对盐岩时效的影响[J]. 岩石力学与工程学报,2000,19(3):270-275.(YANG Chunhe,BAI Shiwei,WU Yimin. Stress level and loading path effect on time dependent properties of salt rock[J]. Chinese Journal of Rock Mechanics and Engineering,2000,19(3):270-275.(in Chinese))
|
[3] |
YANG C,DAEMEN J J K,YIN J H. Experimental investigation of creep behavior of salt rock[J]. International Journal of Rock Mechanics and Mining Sciences,1999,36(2):233-242.
Your browse does not support frame! | | | |