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EFFECTS OF CHEMICAL EROSION ON UNIAXIAL COMPRESSIVE STRENGTH AND MESO-FRACTURING BEHAVIORS OF ROCK
岩石单轴抗压强度与破裂特征的化学腐蚀效应

Chen Sili,Feng Xiating,Li Shaojun,
陈四利
,冯夏庭,李邵军

岩石力学与工程学报 , 2003,
Abstract: Erosive effects of water chemistry on the uniaxial compressive strength of rocks are studied according to the meso-mechanical experiments, and the microscope images and entire images of the meso-fracturing process are obtained. The meso-fracturing behaviors and erosive mechanism of rock are analyzed under chemical erosion. Therefore, the results can be used as scientific references to setting up the mechanical model of the chemical damage of rock and evaluating the long-term stability of the rock and soil engineering.
液态CO2相变破岩技术述评研究
Research and review about the liquid CO2 phase-transforming rock fracturing technology
 [PDF]

谢晓锋,李夕兵,李启月,马海鹏,方莹,刘小雄
XIE Xiaofeng
, LI Xibing, LI Qiyue, MA Haipeng, FANG Ying, LIU Xiaoxiong

- , 2018,
Abstract: 作为物理破岩技术,液态CO2相变致裂技术自研发以来,其应用由煤层增透逐渐扩展到岩体破裂,克服了炸药爆破破坏性大、危险性高的缺点,为岩体开挖提供了新的思路。随着CO2相变破岩技术的发展,泄放能量不断提升,施工工艺不断进步,破岩效果不断增强。但其破岩过程及机理的研究刚起步,理论研究落后于工程实践,这在一定程度上制约该技术的进一步发展,制约其向深部地下工程扩展和大规模推广。本文针对液态CO2相变破岩技术的起源、原理、应用和研究进展等方面进行介绍,并对上述科学问题及后续研究重点进行展望。
Since the liquid CO2 phase-transforming rock fracturing technology has been developed, its application has been widened from the area of coal seam permeability increment to rock fracture and fragmentation. As a physical rock fracturing technology, it overcomes the drawbacks of the devastating damage and high risk of explosive detonation, and enlightens a new thought of rock excavation method. With the development of phase-transforming fracturing technology, the energy utilization rate of fracturing has been promoted, and the operation technique has been improved, while the fracturing performance is becoming better and more controllable. However, the investigation on the mechanism of this technology has just started, and some significant issues still remain untouched. The theory on understanding the phase-transforming fracturing technology is far more behind its usage in practical engineering, which limits its further development and wider application in the area of rock fragmentation, particularly in deep underground rock engineering. This paper introduced the origination and principle of the liquid CO2 phase-transforming (rock) fracturing technology, overviewed the current applications and progresses. Besides, key scientific problems and future research emphasis were prospected
单轴压缩砂岩水力压裂力学特性试验研究
Mechanical characteristics of sandstone under hydraulic fracturing by uniaxial compression
 [PDF]

杨红伟,许江,聂闻,林骏,龚涛
- , 2016, DOI: 10.11835/j.issn.1000-582X.2016.05.012
Abstract: 采用RLW-2 000 M微机控制煤岩流变仪,以砂岩为研究对象,重点分析单轴压缩条件下水压应变水压体积曲线演化规律,从水压、应变和水压体积三者关系反映水力压裂过程的力学特征;结合断裂力学观点分析了砂岩的水力压裂裂缝形态及破坏类型。实验结果表明:岩石在水力压裂过程的变形演化规律可分为4个阶段,揭示了孔隙裂隙的注水阶段、弹性变形阶段、体积膨胀阶段和贯通破裂阶段的特征;利用乘幂负指数拟合方程,能较好地模拟ε1-t与P-Vp曲线演化规律且精度较高;裂缝起裂和裂缝扩展延伸过程存在拉伸变形和剪切变形的相互作用。
In this paper, mechanical characteristics of sandstone under hydraulic fracturing were investigated by uniaxial compression tests (using RLW-2000M Coal and Rock Computer Controlled Rheological Testing Machine). Transformation laws of strain-pore water pressure curves are the research highlights. The mechanical characters of sandstone under hydraulic fracturing were discussed based on pore water pressure, rock strain and water volume. In addition, we assessed the hydraulic fracture morphology and failure type of sandstone. The results show that the typical deformation evolution involoves four stages in hydraulic fracturing process, and well the characteristics of the pore fissure water injection stage, the elastic deformation stage, the volume expansion stage, and the gloable rupture stage are revealed. The power of negative exponential can fit the ε1-t and the P-Vp curves. Tensile deformation and shear deformation interact with each other during the crack initiation and propagation process
坏数据的追踪辨识  [PDF]
倪明高晓萍单渊达
电力系统自动化 , 1994,
Abstract: 针对目前我国地区电网的特点,提出一种利用时间序列方法建立多个模型进行追踪辨识的坏数据处理方法。由于该方法与网络结构无太大关系,因而不仅适用于环网,也适用于开式网。另外,本方法对量测系统的冗余度要求不高,并且能给出坏数据的替代值,从而保证了系统的可观测性。已用于一实际地区电网,试验结果证明了本方法的有效性。
代码坏味的处理顺序  [PDF]
高原?,刘辉?,樊孝忠?,牛振东?,邵维忠?
软件学报 , 2012, DOI: 10.3724/SP.J.1001.2012.04152
Abstract: 选取了10种具有代表性的代码坏味进行研究.从每种代码坏味的产生原因、症状、对软件的影响以及相应的处理这4个方面进行分析,提出了一个代码坏味处理顺序的优先级.通过问卷调查和两个实验,对代码坏味处理顺序优先级进行了初步验证.
Experimental evidence of the compatibility of the cumulative electromagnetic energy release data, with the hierarchical models for the catastrophic fracturing process
D. Mastrogiannis, V. Hadjicontis,C. Mavromatou
Natural Hazards and Earth System Sciences (NHESS) & Discussions (NHESSD) , 2011,
Abstract: In this paper, we performed experiments of uniaxial compression of granite samples and recorded time series of electromagnetic pulses during the evolution of the catastrophic fracturing process. The cumulative energy release of the electromagnetic emission (EME) up to the critical point at the moment of rupture was then calculated. It was shown, that the validity of the proposed hierarchy models for the catastrophic fracturing process of composite materials, in analogy to critical phenomena, can be experimentally established not only via acoustic emission data, but via electromagnetic emission data as well. The above conclusion could be a useful tool for the improvement of the earthquake prediction method, based on precursory electromagnetic signals.
Fracturing Pressure in Oil and Gas Well Drilling  [cached]
Chuanliang Yan,Jingen Deng,Baohua Yu,Lianbo Hu
Research Journal of Applied Sciences, Engineering and Technology , 2013,
Abstract: During oil and gas well drilling, when the drilling fluid density is too high, not only tensile fracturing but also shear fracturing may occur on the wellbore. The possible fracturing modes and corresponding calculation formulas of fracturing pressure were present. Moreover, the influence of the magnitude and non-uniformity of in-situ stress, the pore pressure and the formation strength on fracturing mode was quantitatively analyzed. The results showed that: the risk of shear fracturing was higher with small non-uniformity of in-situ stress; when the horizontal stress was small, shear fracturing and tensile fracturing both probably happened and a higher in-situ stress leaded to less probability of tensile fracturing; the potential of tensile fracturing increased with the increasing of formation strength and pore pressure.
The Charpy fracturing process in ductile range  [PDF]
S. Vodopivec,B. Arzen?ek,J. Vojvodi? Tuma,R. Celin
Metalurgija , 2008,
Abstract: The fracturing of structural steels in Charpy ductile range is investigated. The dependences load versus deflection and time were recorded and the consumption of energy for different fracturing events, as f.i. plastic deflection and crack propagation was assessed. The micromorphology of the crack surface and lips is examined and the succesions of decohesion mechanims is deduced. The aproximate change of fracturing temperature due to adiabatic dissipation of deformation energy as heat is deduced, also.
Fracturing highly disordered materials  [PDF]
A. A. Moreira,C. L. N. Oliveira,A. Hansen,N. A. M. Araujo,H. J. Herrmann,J. S. Andrade Jr
Physics , 2012, DOI: 10.1103/PhysRevLett.109.255701
Abstract: We investigate the role of disorder on the fracturing process of heterogeneous materials by means of a two-dimensional fuse network model. Our results in the extreme disorder limit reveal that the backbone of the fracture at collapse, namely the subset of the largest fracture that effectively halts the global current, has a fractal dimension of $1.22 \pm 0.01$. This exponent value is compatible with the universality class of several other physical models, including optimal paths under strong disorder, disordered polymers, watersheds and optimal path cracks on uncorrelated substrates, hulls of explosive percolation clusters, and strands of invasion percolation fronts. Moreover, we find that the fractal dimension of the largest fracture under extreme disorder, $d_f=1.86 \pm 0.01$, is outside the statistical error bar of standard percolation. This discrepancy is due to the appearance of trapped regions or cavities of all sizes that remain intact till the entire collapse of the fuse network, but are always accessible in the case of standard percolation. Finally, we quantify the role of disorder on the structure of the largest cluster, as well as on the backbone of the fracture, in terms of a distinctive transition from weak to strong disorder characterized by a new crossover exponent.
解冻“渐冻人”  [PDF]
王丽娜
科技导报 , 2014,
Abstract: 通常,疾病患者不仅要忍受肉体的痛苦,往往还忧心忡忡,担心是否能够痊愈、是否有其他并发症等等,这给患者带来严重的心理负担,在精神上也经受折磨。“渐冻人症”患者更是如此——他们的肢体不受控制,但具有清醒的意识,精神上的痛苦可想而知。
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