Load relief rupture mechanism based on particle flow rocklike material

Load relief rupture mechanism based on particle flow rocklike material

Peijie Lou Shuling Liang Mingming Feng Yishun Bu Xinyi Huang 

School of Civil and Architectural Engineering, Anhui University of Science and Technology, Huainan 232001, China

Opening Laboratory for Deep Mine Construction, Henan Polytechnic University, Jiaozuo 454000, China

Corresponding Author Email: 
31 December 2018
| Citation



 The purpose of this study was to investigate the microscopic mechanism of rock load relief rupture may be unveiled. The PFC2D meso-structure parameters are calibrated based on a set of results from uniaxial compression test on indoor rocklike materials, and then the particle flow software is used to simulate biaxial compression and load relief tests. Study shows that, in the numerical simulation test of biaxial compression, only a main shear rupture zone forms after the rocklike material is damaged. Local shear rupture zone seems weak; while in the numerical simulation test of load relief, there are multiple shear rupture zones produced after it gets destroyed. The biaxial compression shear rupture zone appears wider than the unload shear rupture zone. from the ratio of the shear cracks to the tensile cracks when unloading, we find that a lot of tensile cracks will generate immediately if suddenly unloaded, so that the tensile failure occurs. subsequently, the shear and tensile cracks remain stable at a certain value, that is, the specimen fails due to the joint tension and shear. the simulation test is conducted with the analysis of the relationship between the uniaxial compression microcracks and the stress, and it is found therefrom that the stress curve of the sample is mainly subjected to change with the number of microcracks. The findings of this study may serve as to avoiding many work accidents have been incurred by work load relief in recent years


 particle flow, unload, mesoscopic rupture mechanism

1. Introduction
2. Lab test
3. Determination of mesostructured parameters of PFC2D
4. Analysis of the relationship between the microcracks and stress
5. Rocklike unloading simulation test
6. Conclusions

Chen W. Z., Lü S. P., Guo X. H., Qiao C. J. (2010). Unloading confining pressure for brittle rock and mechanism of rock burst. Chinese Journal of Geotechnical Engineering, Vol. 32, No. 6, pp. 963-969.

Fan Y. B., Wu F. Q., He H. F., Ren A. W. (2011). Experiment research about mechanical characteristic of gneissic granite while confining pressure is unloaded. Hydrogeology & Engineering Geology, Vol. 38, No. 3, pp. 54-58. http://doi.org/10.3969/j.issn.1000-3665.2011.03.010

Huang S. W., Si T. H., Feng J. W., Cao Y. Q. (2009). Analysis of surrounding rock pressure of Niuhushan tunnel under unloading effect. Chinese Journal of Underground Space and Engineering, Vol. 5, No. 1, pp. 79-84. http://doi.org/10.3969/j.issn.1673-0836.2009.01.015

Huang W., Shen M. R., Zhang Q. Z. (2010). Study of unloading dilatancy property of rock and its constitutive model under high confining pressure. Chinese Journal of Rock Mechanics and Engineering, Vol. 29, No. S2, pp. 3475-3481.

Hunag R. Q., Huang D. (2008). Study on deformation characteristics and constitutive model of rock on the condition of unloading. Advances in Earth Science, Vol. 23, No. 5, pp. 441-447. http:// doi.org/10.3321/j.issn:1001-8166.2008.05.001

Li J. L., Wang R. H., Jiang Y. Z., Liu J., Chen X. (2010). Experimental study of sandstone mechanical properties by unloading triaxial tests. Chinese Journal of Rock Mechanics and Engineering, Vol. 29, No. 10, pp. 2034-2041.

Luo Y. (2007). Simulation of soil mechanical behaviors using discrete element method based on particle flow code and its application. Zhejiang University.

Shi C., Xu W. Y. (2015). Technique and practice of numerical simulation of particle flow. Beijing, China Architecture & Building Press.

Xia C. C., Yan Z. J., Wang X. D., Zhang C. S., Zhao X. (2009). Research on elastoviscosity constitutive relation of marble under unloading condition. Chinese Journal of Rock Mechanics and Engineering, Vol. 28, No. 3, pp. 459-466.

You M. Q. (2000). Strength and deformation of rock specimens. Beijing: Geological Publishing House.

Zhang L. M. (2009). Experimental and theoretical study on macroscopic and mesoscopic failure mechanism of rock mass under loading and unloading conditions. Xi`an University of Architecture and Technology.

Zhang L. M., Wang Z. Q., Shi L. (2011). Experimental study of hard rock failure characteristic under unloading condition. Chinese Journal of Rock Mechanics and Engineering, Vol. 30, No. 10, pp. 2012-2018.