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冻融岩体力学特性实验研究 总被引：5，自引：0，他引：5
岩石的冻融破坏是寒区岩石工程中常遇到的主要病害之一。通过对3种岩石进行冻融循环试验及电镜微观扫描的方法,研究了不同性质的岩石在冻融条件下的劣化损伤机制,分析了其冻融破坏机理; 并针对不同性质的岩石总结提出了2种不同的冻融劣化模式:裂隙扩展劣化模式和颗粒析出劣化模式; 通过不同冻融循环次数后的3种饱和岩石单轴抗压强度试验,得到了不同性质岩石的单轴抗压强度与冻融循环次数的拟合关系表达式,初步量化了循环冻融对寒区岩石强度衰减的影响,具有一定参考价值,为今后岩石冻融劣化研究和寒区工程建设及工程安全运营提供了可靠的依据。 相似文献
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地震易发地区的锚固岩石边坡,需要研究其地震稳定性。对于锚固典型岩石边坡,在考虑水平与竖向地震力、张裂缝积水深度、坡顶超载、锚索倾角、锚索位置、锚索拉力及静水与动水压力等的条件下,运用拟静力和拟动力方法分别推导了不同工况条件下其抗滑和抗倾覆地震安全系数。分析表明,竖向向上地震力有利于锚固岩石边坡的抗滑稳定,而竖向下的地震力有利于锚固岩石边坡的抗倾覆稳定;在相同工况条件下,当岩体放大系数等于1.0时,拟动力与拟静力方法所得锚固岩石边坡地震安全系数相差无几,但是,当岩体放大系数逐渐增大时,拟动力方法所得地震安全系数越来越明显地小于拟静力方法所得地震安全系数。因此,在抗震设计当中适当的考虑岩体放大系数,将会有利于锚固岩石边坡的安全设计。 相似文献
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疲劳是岩石的重要力学特性之一,与工程的安全稳定密切相关.在循环荷载作用下,岩石初始损伤不断累积、加剧,最终导致岩石的失稳破坏,从而诱发工程灾变.阐述了近年来基于声发射、红外辐射技术开展岩石疲劳损伤与破坏方面的研究进展.首先论述了研究人员采用声发射时域参数、声发射空间演化以及Felicity比开展岩石疲劳损伤特性的研究进展.进而,针对研究人员采用声发射时域参数、损伤变量、分形维值、Felicity比、加卸载响应比、RA以及b值等参数开展岩石疲劳破坏前兆的研究进展进行讨论.在此基础上,论述了研究人员采用红外辐射技术开展岩石疲劳损伤与破坏前兆的研究进展.最后,提出了今后岩石疲劳损伤与破坏前兆研究中需要进一步深入解决的几点问题.本文可对深入认识岩石疲劳损伤机理、破坏前兆特征起到积极的促进作用. 相似文献
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百善煤矿64采区超薄基岩区域地质储量210万t,基岩厚度均小于20m,对安全回采造成了巨大影响。在分析煤矿主采煤层赋存、顶板岩石力学地质特征及水文地质条件的基础上,重点分析了超薄风化基岩及松散层内含(隔)水层的岩石特征及强风化岩石泥化对工作面开采的影响。以理论计算、现场实测数据和开采实践为依据,重点研究分析了风化基岩和含(隔)水层的物理特征及强风化岩石泥化对"两带"发育高度的影响,并设计了合理的安全保护煤柱。实践表明:超薄基岩区域强风化岩石软弱、泥化、风化对工作面回采"两带"发育高度有降低作用,有利于工作面的安全回采。 相似文献
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岳豪杨胜利翟瑞昊张燊崔轩 《岩土力学》2023,(4):1230-1244
含砂岩石是发生突水溃砂灾害前在高位关键层形成的特殊岩石,其强度与力学性质均与普通岩石不同,决定着高位关键层的稳定性。研究发现：不同裂隙角的裂隙岩石与含砂岩石具有不同的特征应力,且随着裂隙角的增加,裂隙岩石与含砂岩石的起裂应力、损伤应力和峰值应力均增加,双峰应力先增加后减小。相同裂隙角下的含砂岩石各特征应力均小于裂隙岩石,说明砂体对岩石特征应力具有弱化效应。从破坏形态来看,裂隙岩石易呈现翼形拉伸裂隙,含砂岩石在低裂隙角（30°）条件下形成拉伸裂隙,高裂隙角（60°）条件下易形成剪切裂隙,表明砂体进入岩石裂隙后对岩石具有剪切效应。同时建立了充砂力学模型,指出了含砂岩石强度小于裂隙岩石的原因是砂体降低了岩石的摩擦系数。根据声发射累计振铃计数定义了岩石损伤量并分析了含砂岩石致灾机制,现场溃砂灾害可分为4个阶段：弹性变形阶段、裂隙扩展阶段、蓄砂储能阶段、溃砂释能阶段。最后利用PFC2D验证了裂隙岩石与含砂岩石的差异性,分析了不同类型岩石的能量演化规律。研究结果可作为煤矿顶板突水溃砂现象的前兆信息识别,有助于指导突水溃砂工作面的安全生产。 相似文献
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数字图像技术在岩石细观力学研究中的应用 总被引：1，自引：0，他引：1
岩石内部的细观组成和结构决定了其在外力作用下的应力-应变状态,进而控制了其宏观力学响应和破坏机制。数字图像处理技术作为一种材料细观尺度上的空间结构精确测量和数字表述手段,已广泛应用于土、岩石及混凝土的细观结构定量分析中。应用数字图像处理进行的岩石细观力学研究是对岩石力学研究方法的革新。现阶段主要研究内容包括：岩石裂隙隙宽的非接触测量,数字表述岩石结构的非均匀性,进行岩石细观力学行为分析,将提取的岩石数字特征值与相应的岩石物性结合以实现岩石流-固耦合研究,建立基于数字图像技术的岩石细观力学数值模拟方法。在研究相关文献的基础上,对数字图像技术在岩石细观力学定量研究中的成果进行客观评述,探讨各种方法的优缺点,分析展望数字图像技术在岩石细观研究领域中的应用前景。 相似文献
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贵州某机场的主要工程地质问题分析及其处理措施建议 总被引：1，自引：2，他引：1
贵州某机场为山区高填方机场，最大填方高度近60m，场址沟谷发育，基底为软硬交替的、顺倾向岩层的斜坡地区，笔者就该机场的主要工程地质问题一边坡稳定问题、沉降问题、地表水和地下水的排泄问题进行了不同程度的研究并提出了相应的处理措施。 相似文献
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The selection of the disposal site is probably the most important step in the development of solid waste management. In site selection, geology plays a determining role. This study evaluates the characteristics of the environment on the basis of the geological, hydrogeological and geo-engineering properties of the solid waste site of the Sivas city, Turkey. The area is underlain by the Oligocene-Miocene rocks which have limited aquifer properties. Thin Quaternary alluvium and soil cover overlie the Oligo-Miocene rocks, which are represented as well graded sand and inorganic silt of low plasticity. The Quaternary alluvium and soil cover are classified as inorganic clays having a low plasticity and the permeability varies from 1.2×10−6 to 3.11×10−6 m/s. These values are much higher than 1×10−8 m/s, which is accepted for waste disposal standards. Seepage waters have a potential to pollute the ground water and the Kızılırmak River, which is 500 m to the southwest of the waste disposal area and because the disposal site is close to the river, the potential for flash flooding poses a high pollution risk. The waste disposal area must be covered by clay layers or an impervious artificial membrane. In addition, seepage must be controlled and removed from the site. 相似文献
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The Zonguldak province is a coastal settlement area that has been suffering from serious natural and human-induced environmental
problems sourced by its geology and geomorphology. Since the province locates at the heart of a coal-producing basin, the
geo-environmental problems related to mining activities such as esthetic degradation, disposal of mining wastes and subsidence
of the abandoned coal galleries are badly affecting every day life in Zonguldak province. Disposal of municipal wastes is
also a big problem since only one municipality out of 32 has a sanitary disposal area. The rest of the municipalities dispose
their solid wastes to rivers or to the sea. The province has also some health problems, which are pointed out in the literature,
related to coal mining and geologic environment. These are cytogenetic damage in peripheral lymphocytes and pheumoconiosis
(most commonly seen at coal workers), goiter and cancer. Landslides are the most important hazards in the area since 13% of
the total surface of the Zonguldak is affected by landslides. In this study, considering the hazard potential special attention
is given to deep landslides and using the stepwise forward conditional logistic regression technique, the landslide susceptibility
map for the Zonguldak province is produced. The results showed that the most important independent variables governing the
landslides are slope gradient, volcanic, and sedimentary rocks of Eocene and clastic and carbonate units of Cretaceous. The
landslide map is used as a base map for the production of geo-hazard reconnaissance map on which areas subjected to other
important geo-hazards (flood, earthquake and subsidence) are also shown to provide guidance for both existing settlement areas
to take the necessary preventive measures and for new developing settlement areas to avoid the problematic areas. 相似文献
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深地质处置目前被国际上公认为是处置高放废物的最有效可行的方法。我国采用多重工程屏障系统和适宜的地质体共同作用来确保与生物圈的安全隔离。缓冲材料是高放废物重要的工程屏障材料之一,我国选用高庙子钠基膨润土作为缓冲材料的基础材料。膨润土作为缓冲材料的一个重要性能表现为缓冲孔隙水的化学变化。介绍了GMZ-1钠基膨润土大气条件下与蒸馏水的反应试验,并对试验结果进行了讨论。批式试验反应溶液中钠离子来源于钠基膨润土层间阳离子和矿物溶解,镁离子来源于钠基膨润土层间阳离子,钾离子和钙离子来源于矿物溶解,相关研究认识对于高放废物处置库近场核素迁移研究和评价工程屏障的长期稳定性具有重要意义。 相似文献
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《Applied Geochemistry》2005,20(2):443-451
The influence of water-extractable organic matter from 6 Opalinus Clay (OPA) samples from Mont Terri and Benken (Switzerland) on the sorption of Ni(II), Eu(III) and Th(IV) has been measured using an ion exchange technique. OPA is considered to be one of the potential host rocks for the deep geological disposal of high-level and long-lived intermediate-level radioactive waste in Switzerland. Within the range of estimated uncertainties, no significant differences in sorption were observed in most cases as compared with suitable synthetic waters devoid of organic C. Only in certain individual cases were slight reductions in sorption (less than a factor of 5) for Eu(III) and Ni(II) found. The results of accompanying laser fluorescence spectroscopy experiments did not show any influence of the extracts on Cm(III) speciation. This would suggest that the reduction of sorption occasionally observed in the ion exchange experiments is probably not caused by the formation of complexes between the radionuclides and the organic matter in the extracts, but is rather due to an underestimation of systematic uncertainties. From these findings, and from UV–VIS spectroscopic characterisation of the organic matter in the extracts, it can be concluded that only a negligible fraction of the organic matter present may be in the form of humic or fulvic acids. It is consequently justified to put aside overly conservative assumptions with respect to the complexing behaviour of the organic matter used towards the metal ions investigated and their chemical analogues. In view of the site-specific character of the present study, these conclusions may not be arbitrarily applied to other geological formations considered as possible host rocks for the disposal of radioactive waste. 相似文献
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This paper presents the process of ANDRA for the characterization of backfilling materials for a deep radioactive waste disposal in crystalline rocks.
The experimental programme was developed in collaboration with the CEA/DRDD; the main objective was to build a comprehensive methodology of characterization, applied to the French Ca-smectite clay, ldFo-Card clay selected from several French deposits.
For this programme specific experimental facilities are needed adapted to this kind of material. The main results concerning thermal, hydraulic and radioelement transfer properties are presented for pure Fo-Ca clay, or used in mixtures with different components such as sand, graphite or talc.
Hydraulic properties of Fo-Ca and Na-bentonite MX-80 are compared and discussed. 相似文献
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中国高放废物深地质处置的缓冲材料选择及其基本性能 总被引：12，自引：0，他引：12
人类的许多生产、生活活动均可能产生不同活度的放射性废物,其中高放废物的安全处置倍受全球科学家和广大公众所重视。目前深地质处置被国际上公认为处置高放废物的最有效可行的方法。借鉴国外成熟的技术和经验,我国采用多重工程屏障系统(包括废物固化体、废物容器及其外包装和缓冲/回填材料)和适宜的围岩地质体共同作用,来确保高放废物与生物圈的安全隔离。膨润土由于具有极低的渗透性和优良的核素吸附等性能而被国际上选作缓冲材料的基础材料。经过全国膨润土矿床筛选,我国高放废物深地质处置库缓冲材料的研究以产自高庙子膨润土矿床深部的钠基膨润土作为基本组成材料。本文介绍了高庙子膨润土矿床的地质特征以及高庙子钠基膨润土的基本特征。该膨润土与国外同类型材料相比具有蒙脱石含量高(75%左右)、杂质矿物相对较少的特点,该材料的系统和深入研究对于开发我国缓冲回填材料技术、确保高放废物的安全有效处置有重要意义。 相似文献
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E. Mazor B. Th. Verhagen J. P. F. Sellschop M. T. Jones L. G. Hutton 《Environmental Geology》1981,3(4):195-199
In the reconstruction of the chemical evolution of mineral waters, sodium exchange for calcium and magnesium, upon contact
with soil and rocks, is often suggested. Such a process has been observed to take place on a large (and rapid) scale in NaCl
waste disposal: that infiltrated to the local groundwater at Lobatse, Botswana. The process was repeated in laboratory experiments.
Visiting Scientist at the Nuclear Physics Research Unit, University of the Witwatersrand, Johannesburg, South Africa, during
1972. 相似文献
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Man does not only extract material from the Earth but increasingly uses the underground for storage and disposal purposes. One of the materials that might be disposed of this way is high-level nuclear waste. The development of safe disposal procedures, the choice of suitable host rocks, and the design of underground facilities have taken much time and money, but commissions in several countries have presented reports showing that — and how — safe geological disposal will be possible in such a way that definite isolation from the biosphere is achieved. Political views have changed in the past few years, however, and there is a strong tendency now to require that the high-level waste disposed of will be retrievable. Considering the underlying arguments for isolation from the biosphere, and also considering waste policy in general, this provides an irrational context. The development of new procedures and the design of new disposal facilities that allow retrieval will take much time again. A consequence may be that the high-active, heat-generating nuclear waste will be stored temporarily for a much longer time than objectively desirable. The delay in disposal and the counterproductive requirement of retrievability are partly due to the fact that earth-science organisations have failed to communicate in the way they should, possibly fearing public (and financial) reactions if taking a position that is (was?) considered as politically incorrect. Such an attitude should not be maintained in modern society, which has the right to be informed reliably by the scientific community. 相似文献