东北大学学报(自然科学版)
東北大學學報(自然科學版)
동북대학학보(자연과학판)
JOURNAL OF NORTHEASTERN UNIVERSITY(NATURAL SCIENCE)
2015年
9期
1347-1352
,共6页
红砂岩%分级加卸载%应力水平%短时蠕变%声发射
紅砂巖%分級加卸載%應力水平%短時蠕變%聲髮射
홍사암%분급가사재%응력수평%단시연변%성발사
red sandstone%step loading and unloading%stress level%short-time creep%acoustic emission
为认识岩石蠕变过程中的声发射特征,进行了短时蠕变声发射试验,研究了红砂岩在不同应力水平下的声发射特征。试验结果表明:在减速蠕变至等速蠕变过程中,声发射事件率与能率随时间的增大而减小,并且减小的幅度随着应力水平的增大而减小;当加载应力约为峰值应力的40%~60%时,声发射振幅随时间的增大而减小;当加载应力约为峰值应力的70%~80%时,声发射振幅保持相对稳定。在加速蠕变阶段,声发射振幅发生跃迁的频率显著增大,而声发射事件率与能率在加速蠕变的中后期开始增大。因此,可根据不同应力水平下的声发射特征,对红砂岩不同蠕变阶段进行辨别。
為認識巖石蠕變過程中的聲髮射特徵,進行瞭短時蠕變聲髮射試驗,研究瞭紅砂巖在不同應力水平下的聲髮射特徵。試驗結果錶明:在減速蠕變至等速蠕變過程中,聲髮射事件率與能率隨時間的增大而減小,併且減小的幅度隨著應力水平的增大而減小;噹加載應力約為峰值應力的40%~60%時,聲髮射振幅隨時間的增大而減小;噹加載應力約為峰值應力的70%~80%時,聲髮射振幅保持相對穩定。在加速蠕變階段,聲髮射振幅髮生躍遷的頻率顯著增大,而聲髮射事件率與能率在加速蠕變的中後期開始增大。因此,可根據不同應力水平下的聲髮射特徵,對紅砂巖不同蠕變階段進行辨彆。
위인식암석연변과정중적성발사특정,진행료단시연변성발사시험,연구료홍사암재불동응력수평하적성발사특정。시험결과표명:재감속연변지등속연변과정중,성발사사건솔여능솔수시간적증대이감소,병차감소적폭도수착응력수평적증대이감소;당가재응력약위봉치응력적40%~60%시,성발사진폭수시간적증대이감소;당가재응력약위봉치응력적70%~80%시,성발사진폭보지상대은정。재가속연변계단,성발사진폭발생약천적빈솔현저증대,이성발사사건솔여능솔재가속연변적중후기개시증대。인차,가근거불동응력수평하적성발사특정,대홍사암불동연변계단진행변별。
The characteristics of acoustic emission (AE)of the red sandstone during short-time creep were studied under different stress level.The results show that the AE event ratios and energy ratios decrease with time increase during the period from decelerated creep to steady creep, and the corresponding reductions in amplitude decrease with the increasing stress level.The AE amplitude decreases and keeps relatively stable when the stress is about 40%~60% and 70%~80% of peak stress,respectively.The AE amplitude transition frequency increases obviously during the accelerated creep stage,and its event ratio and energy ratio begin to increase in the mid-late stage of accelerated creep. Therefore, the creep stage of red sandstone can be distinguished by the AE characteristics.