岩石力学与工程学报
巖石力學與工程學報
암석역학여공정학보
CHINESE JOURNAL OF ROCK MECHANICS AND ENGINEERING
2015年
z1期
2827-2836
,共10页
周辉%孟凡震%张传庆%卢景景%徐荣超
週輝%孟凡震%張傳慶%盧景景%徐榮超
주휘%맹범진%장전경%로경경%서영초
岩石力学%结构面%直剪试验%声发射能量率%声发射撞击率%起伏高度%法向压力
巖石力學%結構麵%直剪試驗%聲髮射能量率%聲髮射撞擊率%起伏高度%法嚮壓力
암석역학%결구면%직전시험%성발사능량솔%성발사당격솔%기복고도%법향압력
rock mechanics%discontinuity%direct shear test%acoustic emission energy rate%acoustic emission hit rate%asperity height%normal stress
为研究结构面岩体在压剪荷载作用下的声发射特征和规律,利用水泥砂浆作为模型材料制作具有不同起伏高度的不规则锯齿形结构面,研究不同起伏高度、不同剪切速率和不同法向压力下声发射参数的变化规律和发生机制。试验结果表明:结构面剪切时理想的累积撞击曲线可以划分为平静期、缓慢上升期和急剧上升期3个阶段;随结构面起伏高度的增大,发生宏观剪切破坏时能量率峰值变大、累积撞击数变小;随剪切速率的增大,能量率曲线和撞击率曲线在剪切过程中波动性增强,能量率峰值、撞击率峰值和累积能量随剪切速率的增大有减小的趋势;声发射参数随法向压力变化规律性不强,但随法向压力的增大,破坏时对应的能量率峰值和累积能量有减小的趋势,撞击率峰值和累积撞击数有增大的趋势。研究成果可为声发射技术用于监测和预报现场结构面岩体的静力或动力剪切破坏提供指导。
為研究結構麵巖體在壓剪荷載作用下的聲髮射特徵和規律,利用水泥砂漿作為模型材料製作具有不同起伏高度的不規則鋸齒形結構麵,研究不同起伏高度、不同剪切速率和不同法嚮壓力下聲髮射參數的變化規律和髮生機製。試驗結果錶明:結構麵剪切時理想的纍積撞擊麯線可以劃分為平靜期、緩慢上升期和急劇上升期3箇階段;隨結構麵起伏高度的增大,髮生宏觀剪切破壞時能量率峰值變大、纍積撞擊數變小;隨剪切速率的增大,能量率麯線和撞擊率麯線在剪切過程中波動性增彊,能量率峰值、撞擊率峰值和纍積能量隨剪切速率的增大有減小的趨勢;聲髮射參數隨法嚮壓力變化規律性不彊,但隨法嚮壓力的增大,破壞時對應的能量率峰值和纍積能量有減小的趨勢,撞擊率峰值和纍積撞擊數有增大的趨勢。研究成果可為聲髮射技術用于鑑測和預報現場結構麵巖體的靜力或動力剪切破壞提供指導。
위연구결구면암체재압전하재작용하적성발사특정화규률,이용수니사장작위모형재료제작구유불동기복고도적불규칙거치형결구면,연구불동기복고도、불동전절속솔화불동법향압력하성발사삼수적변화규률화발생궤제。시험결과표명:결구면전절시이상적루적당격곡선가이화분위평정기、완만상승기화급극상승기3개계단;수결구면기복고도적증대,발생굉관전절파배시능량솔봉치변대、루적당격수변소;수전절속솔적증대,능량솔곡선화당격솔곡선재전절과정중파동성증강,능량솔봉치、당격솔봉치화루적능량수전절속솔적증대유감소적추세;성발사삼수수법향압력변화규률성불강,단수법향압력적증대,파배시대응적능량솔봉치화루적능량유감소적추세,당격솔봉치화루적당격수유증대적추세。연구성과가위성발사기술용우감측화예보현장결구면암체적정력혹동력전절파배제공지도。
To investigate the acoustic emission(AE) characteristics and laws of rock discontinuity under compression-shear stress,irregular serrated discontinuities with different asperity height were made of cement mortar and change laws of AE parameters and their mechanism of the discontinuities at different asperity height, shearing velocity and different normal stress are studied. Experimental results indicate that the ideal cumulative hits of discontinuity during shearing can be divided into three stages——quiet period,slow rise period and sharp growth period. It can be found that the peak energy rate increases while cumulative hits decrease with the increase of discontinuity asperity height when macroscopic shear failure occurs. With increase of shearing velocity,curves of energy rate and hit rate become higher volatility and peak energy rate,peak hit rate and cumulative energy tend to decrease. Change laws of AE parameters is not very obvious with the change of normal stress,but peak energy rate and cumulative energy tend to decrease while peak hit rate and cumulative hits increase with the increase of normal stress. Research results can provide guidance for applications of acoustic emission techniques into monitoring and prediction of the static or dynamic shear failure of in-situ rock discontinuities.