首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
SF-1型岩石声发射测试仪是岩石力学实验研究的一种非常有用的测试仪器。它可以用来监测岩石或岩石样品在外力作用下,发生变化过程中由微破裂所产生的声发射现象。它不仅可以研究微破裂与应力、变形、波速、时间等的变化规律,而且还可以进一步研究微破裂与主破裂(大破裂)的关系。所以它在岩石或岩体的变形破坏实验研究中具有重要的意义。多年来,在进行岩石力学研究中一直缺少适用的声发射仪,从而影响了这方面工作的开展。为了当前  相似文献   

2.
固体传压高温高压岩石三轴实验中,固体传压介质是影响实验结果的重要因素,NaCl介质以它流动性好,围压均匀等特点,八十年代以来越来越受到人们青睐。本文用NaCl介质在〈3GPa固体传压三轴流变仪〉上进行了高温高压岩石流变特性的实验研究,并达到了较高的压力(〉2GPa)和温度(〉1200℃);本文同时利用NaCl介质对样品装样方式及温度、压力等相关测定方面进行了研究。  相似文献   

3.
微波遥感技术在岩石力学中的应用   总被引:7,自引:0,他引:7       下载免费PDF全文
耿乃光  樊正芳 《地震学报》1995,17(4):482-486
在岩石加载直至破裂的过程中,对岩石的微波辐射进行了遥感观测研究.使用的微波辐射计的波长为8 mm,2 cm和10 cm.对13种岩石进行了实验.实验表明,在岩石加载过程中,岩石的微波辐射亮度温度随应力的增加而增加.岩石临破裂前微波辐射亮度温度加速增长.这一现象可以看作岩石破裂的一种新前兆. 过去在岩石破裂的红外遥感观测实验基础上提出的遥感岩石力学(或遥感岩石物理学)的概念,由于本实验的新结果扩充了它的内容,由红外遥感扩充到微波遥感,从而也扩大了遥感岩石力学在地震预报研究和岩爆预报研究中的应用前景.   相似文献   

4.
温压条件下岩石破坏前后的力学性质与波速   总被引:9,自引:1,他引:9  
在温压条件下,对大理岩和砂岩进行了全过程应力应变试验,研究了温压条件对岩石的极限强度,残余强度,剪切破裂角的影响,以及岩石破坏前后的弹性模量与波速的变化。得到了在温压条件下,岩石变形全过程中有关弹性参数和力学性质的变化规律,并进行了简要分析。  相似文献   

5.
由中国岩石力学与工程学会高温高压岩石力学专业委员会、中国地震学会构造物理专业委员会联合举办的高温高压岩石力学与构造物理学术研讨会于2007年8月15-19日在辽宁召开.  相似文献   

6.
在岩石加载直到破裂的过程中,对岩石的红外辐射进行了遥感观测研究.使用的主要仪器有瞬态光谱仪、智能光谱仪、红外辐射温度计、红外光谱辐射计和红外热象仪.对26种岩石进行了实验.研究表明,岩石的红外辐射温度随应力的增加而增加;岩石的红外辐射波谱的幅值也随应力的增加而增加.岩石的红外热象的观测结果与岩石的红外辐射温度相一致.某些岩石样品破裂主断层形成前,在未来主断层的位置显示出条带状温度异常热象.本实验将遥感学中的最新技术引入岩石力学,以期在岩石力学中建立一个新的研究领域遥感岩石力学(或遥感岩石物理学).遥感岩石力学可望在地震预报,岩爆预报和岩体应力场的测量中得到应用.   相似文献   

7.
依据高温高压岩石破裂实验结果并结合理论分析,对 附近区域不同深度温压条件下岩石变形破坏性质及破坏失稳的力学行为进行了研究,在一次应力加载循环中,发生破坏的部位随时间具有向深部下迁的趋势。考虑到深度温压条件下岩石的渐进式破坏行为及突发失稳,对主震前震中附近区域小地震活动的增强、平静、活化等现象,以及b值等时间序列参数变化的可能机理进行初步探讨,并简单讨论了两类平静和两类b值变化的可能原因。  相似文献   

8.
影响岩石声发射的几个因素   总被引:8,自引:0,他引:8  
以岩石的损伤本构关系为基础,分析声发射与岩石-试验机共同作用系统稳定性的关系,重点从微观上讨论了试验机刚度和岩石均质变的影响,并从岩石破裂失稳角度分析了围压降低所引起的声发射活动性强现象,最后考虑载荷历史的影响,得到了和主震-余震相对应的声发射模式。  相似文献   

9.
我国实验岩石力学与构造物理学研究的若干新进展   总被引:5,自引:2,他引:5       下载免费PDF全文
马胜利  马瑾 《地震学报》2003,25(5):528-534
简述了近年来我国学者在与地震学和地球内部物理学相关的实验岩石力学和构造物理学研究方面的进展.在此领域的进展主要体现在:大量实验以及数学模拟结果丰富了对岩石脆性破裂过程,特别是结构和介质非均匀条件下破裂过程的认识;在非均匀断层的摩擦行为与失稳成核方面取得了一些新结果,揭示了断层滑动行为的复杂性;在岩石脆塑性转换和塑性流变方面取得了一些新结果,特别是在下地壳和上地幔物质的流变性质方面取得了重要进展;在高温高压岩石物理方面取得了一批实验结果, 并应用于地球内部物质的组成和状态的研究.这些结果为深入理解地球内部物质的物理性质、变形机制及地震物理过程提供了有价值的参考资料.   相似文献   

10.
岩石破裂系分形及分维数测定   总被引:1,自引:3,他引:1  
花岗岩在固体围压三轴压缩下破裂,然后沿主破裂面摩擦滑动(粘滑或稳滑),实际后我们将样品从围压介质铅中剥出来,做成显微薄片。在20倍显微投影仪下观测其主破裂及裂纹系分布,用尺度法统计并计算裂纹系分维。结果表明,8个样品的无标度区(R)都相同,但是随尺度变化,分维值表现出分段线性的特征。当0.05〈R〈0.15mm时,裂纹系分维在1.12-1.41之间,主破裂分维在1.08-1.15之间;当0.15〈  相似文献   

11.
12.
13.
《国际泥沙研究》2014,(4):F0003-F0003
  相似文献   

14.
《国际泥沙研究》2014,(2):F0003-F0003
  相似文献   

15.
《国际泥沙研究》2014,(3):F0003-F0003
  相似文献   

16.
17.
A procedure for short-term rainfall forecasting in real-time is developed and a study of the role of sampling on forecast ability is conducted. Ground level rainfall fields are forecasted using a stochastic space-time rainfall model in state-space form. Updating of the rainfall field in real-time is accomplished using a distributed parameter Kalman filter to optimally combine measurement information and forecast model estimates. The influence of sampling density on forecast accuracy is evaluated using a series of a simulated rainfall events generated with the same stochastic rainfall model. Sampling was conducted at five different network spatial densities. The results quantify the influence of sampling network density on real-time rainfall field forecasting. Statistical analyses of the rainfall field residuals illustrate improvement in one hour lead time forecasts at higher measurement densities.  相似文献   

18.
The partitioning of rain water into throughfall, stemflow and interception loss when passing through plant canopies depends on properties of the respective plant species, such as leaf area and branch angles. In heterogeneous vegetation, such as tropical forest or polycultural systems, the presence of different plant species may consequently result in a mosaic of situations with respect to quantity and quality of water inputs into the soil. As these processes influence not only the water availability for the plants, but also water infiltration and nutrient leaching, the understanding of plant effects on the repartitioning of rain water may help in the optimization of land use systems and management practices. We measured throughfall and stemflow in a perennial polyculture (multi‐strata agroforestry), monocultures of peach palm (Bactris gasipaes) for fruit and for palmito, a monoculture of cupuaçu (Theobroma grandiflorum), spontaneous fallow and primary forest during one year in central Amazonia, Brazil. The effect on rain water partitioning was measured separately for four useful tree species in the polyculture and for two tree species in the primary forest. Throughfall at two stem distances, and stemflow, differed significantly between tree species, resulting in pronounced spatial patterns of water input into the soil in the polyculture system. For two tree species, peach palm for fruit (Bactris gasipaes) and Brazil nut trees (Bertholletia excelsa), the water input into the soil near the stem was significantly higher than the open‐area rainfall. This could lead to increased nutrient leaching when fertilizer is applied close to the stem of these trees. In the primary forest, such spatial patterns could also be detected, with significantly higher water input near a palm (Oenocarpus bacaba) than near a dicotyledonous tree species (Eschweilera sp.). Interception losses were 6·4% in the polyculture, 13·9 and 12·3% in the peach palm monocultures for fruit and for palmito, respectively, 0·5% in the cupuaçu monoculture and 3·1% in the fallow. With more than 20% of the open‐area rainfall, the highest stemflow contributions to the water input into the soil were measured in the palm monocultures and in the fallow. Copyright © 1999 John Wiley & Sons, Ltd.  相似文献   

19.
Red tide, a recurrent phenomenon has become conspicuous in several Kashmir lake ecosystems since 1991. The responsible organism (Euglena pedunculata), a rare flagellate rediscovered in the Kashmir Himalaya (Khan 1993) caused first and unprecedented red tide outbreak, constituting a maximum of 96% of resident numerical phytoplankton density in Dal Lake. At present, conflicting hypotheses exist on the generation of causal assemblage(s) imparting redness to waters: Jeeji Bai (1991) linked its origin to acid precipitation – a fallout of burning oil‐fields during the Gulf War – whilst Khan (1993) holds local factor(s) responsible. Field/experimental studies support the latter contention that the influx of untreated sewage, in unison with warm temperatures, high levels of PhAR, iron and interruption to hydrological flow‐pattern together with absence/or reduction in grazing activity created conducive environmental milieu for red tide outbreak. Dal Lake “red tide” drifted the bloom‐inoculum to other waters, including Lake Wular, where additional ecological niches were carved out, threatening the aesthetic value and biological diversity of Kashmir lakes. Ecological monitoring indicates frequent seasonal red tide occurrence in Dal Lake (including summer‐autumn event of 1998) which testifies its unabated eutrophication status. Further studies are needed on ecological adaptability and biogeographic distribution of this rare and unique red tide‐causing flagellate.  相似文献   

20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号