南华大学学报（自然科学版）2015，Vol.29Issue(4)：43-49,7.
花岗岩高应力强卸荷作用下力学特性试验研究
Experimental Research On Mechanical Properties of Granites Under High Unloading Condition
摘要
Abstract
Based on conventional tri-axial load test of granite rock samples, the confining pressure under condition of high stress prior to the peak is unloaded and the destructivetest of granite with invariable q=σ1 -σ3 is maintained to study the granite deformation, breakage characteristics and strength criterion under unloading condition. The results show that:1 ) The conventional tri-axial failure is predominantly axial deformation, whereas the unloading failure is predominantly radial deformation. The unloading failure characteristics are predominantly radial deformation and volume expansion in the unloading direction. At the unloading state the brittle characteristics are significantly higher than that at the loading state. 2)In the load test,the rock is essentially manifested as shear failure and there are rarely tensile rupture ingredients. During unloading rupture various levels of separation fracture is developed. The shear rupture plane is predominantly conjugation X or local shear failure. 3)With the same initial confining pressure,the greater the unloading point, the shorter the time from confining pressure unloading to damage of rock samples,indica-ting that high unloading point is more likely to cause damage to the rock. 4)Mogi-Coulomb strength criterion is suitable for describing the rock strength characteristics of granite under high unloading action damage.关键词
花岗岩/卸荷/变形特征/三轴试验/强度准则Key words
granite/unloading/deformation features/tri-axial test/strength criterion分类
建筑与水利引用本文复制引用
喻清,丁德馨,白杨,陈璐,陈禹瑄,蒋文文,李浩..花岗岩高应力强卸荷作用下力学特性试验研究[J].南华大学学报（自然科学版）,2015,29(4):43-49,7.基金项目
湖南省教育厅基金资助项目(13C800) （13C800）
衡阳市科技局基金资助项目(2013KS31) （2013KS31）
南华大学创新训练中心校级基金资助项目(201412 （）
201422 （）
201501) （）
南华大学创新团队基金资助项目(NHCXTD04) （NHCXTD04）
