围压作用下岩石冲击破坏与变形特性试验研究  

Research on Characteristic of Impact Damage and Distortion of Rock under Confining Pressure

作　　者：王泽东[1,2] 许金余[1,3] 吕晓聪[1] 刘军忠[1] 张磊[1] 

机构地区：[1]空军工程大学工程学院机场建筑工程系 [2]中国人民解放军93514部队 [3]西北工业大学力学与土木建筑学院

出　　处：《地下空间与工程学报》2011年第2期311-316,334,共7页Chinese Journal of Underground Space and Engineering

摘　　要：采用Φ100 mm分离式霍普金森压杆(SHPB)试验装置研究了不同应力状态的砂岩在冲击荷载作用下的力学性能,分析了不同围压水平下砂岩破坏的变形过程与破坏形态。结果表明:围压水平对砂岩的破坏形态有较大的影响。单轴作用下砂岩为脆性压碎破坏,在围压作用下砂岩的破坏形态同单轴作用下砂岩的破坏形态有较大不同,体现出明显的塑性屈服,屈服后砂岩的应力还在缓慢继续增长,表现出明显的脆延转化特性。不同围压水平下砂岩的破坏也不相同。同时围压水平对砂岩的变形特性也有较大影响。单轴作用下不同应变率加载砂岩在达到最大应力时的应变基本相同,破坏应变随应变率增加稍有增加。围压作用下砂岩的塑性屈服应变大致相同,但破坏时的横向应变随围压水平的增长而减小。A 100-mm-diameter split Hopkinson pressure bar apparatus is applied to research the mechanical properties of sandstone subjected to different stress under impact load and its distortion process and damage form under different surrounding stress.The results indicate,that the surrounding stress has great significance on the damage form.The damage form under surrounding stress differs greatly from that when it is subjected to uniaxial pressure,which is a brittleness crushing damage.It shows distinct plastic yielding and the stress continues to increase slowly after yielding,which is the characteristic of brittleness transforming.The damage form and distortion properties vary greatly under different surrounding stress.The strains in case of uniaxial pressure are approximately the same when the stress goes up to the maximum level with different strain rate and the damage stain increases a little with strain rate.Under surrounding stress,the plastic yielding strains have no difference but when damage happens,the transverse strain decreases with increase of surrounding stress.

关 键 词：砂岩 围压 SHPB试验装置 应变 

分 类 号：O347[理学—固体力学] TU452[理学—力学]