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1.
考虑岩体碎胀效应的采场覆岩冒落规律分析 总被引：2，自引：0，他引：2
应用改进的岩石破裂过程分析系统(RFPA2D),分析了煤层开采过程中上覆岩层发生离层、弯曲、端部和中部开裂直至冒落的全过程,再现了采动影响下冒落带、裂隙带、下沉带3带的形成过程以及裂隙拱的形成发展、整体覆岩的周期性运动模式。数值计算中,引入了冒落岩体的碎胀效应,使得计算结果更合理地反映了现场实际,主要表现在：冒落岩体的碎胀效应及拉伸、剪切破坏联合控制了覆岩的运动模式,随着工作面的不断推进,上覆岩层可呈现出周期性的运动特征;裂隙拱发展到一定高度后,工作面垂直方向上不再扩展,只在工作面推进方向向前扩展,此时裂隙拱拱顶为一近似水平线,冒落带、裂隙带和下沉带3带分明;覆岩运动引起的地表下沉范围和下沉量亦都更符合现场实际。 相似文献
2.
多煤层开采条件下煤层覆岩破坏具有独特的特征，影响矿井生产布置。以陕北某矿为例，以该矿地质采矿条件为基础，采用相似材料模拟实验与数值模拟相结合的方法，通过建立模拟模型，开展了双煤层开采对覆岩的破坏影响研究。结果显示:留设不同宽度的煤柱，采用相似材料模拟和数值模拟2种方法得到的煤层覆岩垮落带高度、裂隙带高度都基本一致；在双煤层开采时，留设的煤柱宽度越大，两个煤层的叠置区域就越小，煤层开采对覆岩的破坏程度就越小。在工作面布置时，建议增大两个煤层的开采距离，并尽量增加煤柱宽度，以减缓覆岩移动破坏范围和破坏程度。研究成果为类似双煤层开采工作面的设计及覆岩破坏控制提供技术支撑。 相似文献
3.
浅埋采空区下远距离煤层开采覆岩破坏直接影响本煤层工作面安全开采和上覆采空区稳定性。针对神东矿区大柳塔煤矿开采实际,采用相似模拟试验、数值计算和现场实测方法研究了2-2煤采空区下伏的5-2煤层开采覆岩运动及裂隙发育规律。研究结果表明,大柳塔煤矿5-2煤层一次采全高开采,覆岩裂隙带贯穿层间岩层导通2-2煤采空区,层间岩层的破断会诱发上覆岩层大面积垮落,工作面出现强烈的矿压显现,同时加剧了上覆采空区围岩结构失稳及地表沉陷。现场实测也表明大柳塔煤矿5-2煤层大采高开采覆岩破坏高度137. 32 m,裂采比20. 2,与模拟结果一致。这些成果可以为大柳塔矿5-2煤层工作面安全开采提供理论依据。 相似文献
4.
5.
工作面回采过程中,覆岩破坏特征对于煤矿水灾害和瓦斯防治具有重要意义,为了进一步研究综放开采覆岩破坏特征。以山西某矿5.82m大采高工作面为试验面,采用分段注水、钻孔电视、地质雷达、微震监测探测覆岩破坏高度,对破坏过程进行了数值模拟研究,并对裂隙演化进行了相似模拟试验,同时对传统经验公式进行了修正,研究结果表明:综放开采垮落带发育高度为43.1m,断裂带发育高度为86.7m;垮落带、断裂带、导水断裂带各测试方法之间相差分别小于4.5%、7.1%、9.0%;工作面采动前,裂隙发育度低,而采动后,裂隙数量明显增多,发育度增加;近煤壁区域为裂隙聚集区,密度曲线呈“蛇”型分布;得到新的适合该矿地质条件下的覆岩导水断裂带发育高度经验公式。 相似文献
6.
深部开采上覆岩层采动裂隙网络演化的分形特征研究 总被引：2，自引：0，他引：2
借助相似模拟材料模型试验,模拟了在深部开采条件下上覆岩层采动岩体裂隙分布状态,运用分形几何理论研究了采动岩体裂隙网络分形维数随开采宽度、采场矿山压力、岩层沉降的动态演化规律,并分析了断层对采动岩体裂隙网络分布演化的影响以及采动岩体裂隙网络在三带的分布特征。结果表明：随开采宽度增加,采动岩体裂隙网络分形维数呈现总体增大趋势,在断层影响下表现出降维特点;分形维数与超前工作面压力和岩层沉降均具有非线性关系;三带采动岩体裂隙网络均具自相似性,冒落带、裂隙带、弯曲带分形维数比为1.082 3:1.139 4:1。 相似文献
7.
以大同矿区同忻煤矿为例,利用关键层理论、物理探测技术和数值模拟,分析双系煤层开采形成的覆岩运动与破坏规律。研究结果表明：（1）石炭二叠系煤层工作面推进至193 m时,覆岩裂隙带发育高度达到最大为174.7 m;（2）物理探测得到3-5^#煤层开采引起的覆岩垮裂带高度约为180 m,综合理论计算与现场实测,确定覆岩裂隙带发育高度与采厚之比为11.7-12.0;（3）侏罗系煤层开采引起的底板破坏及双系间覆岩软弱夹层的缺失为双系煤层采空区联通进一步提供了条件;（4）侏罗系煤层的开采影响石炭二叠系煤层工作面超前支承压力的分布规律,当石炭系煤层工作面位于侏罗系煤层遗留煤柱下方时,超前支撑压力较无采空区时增大12.4%;（5）研究成果揭示了双系开采相互影响关系,为采取安全开采措施、减弱双系开采相互影响程度提供了科学依据。 相似文献
8.
浅埋煤层过沟开采在陕北矿区普遍存在,严重威胁着矿井安全生产和生态健康发展。覆岩采动裂隙及地表裂缝的发育是岩体微裂隙的延伸和扩展的结果,为更加系统地研究浅埋煤层过沟开采覆岩微裂隙的演化规律,以陕北安山井田125203工作面为背景,根据现场沟道剖面及钻孔资料,采用Particle Flow Code (PFC)数值模拟平台构建颗粒流数值采煤模型,模拟分析覆岩微裂隙的发育特征、数量变化规律和力链演化特征,揭示微裂隙的发育规律和地表裂缝发育机理。结果表明:浅埋煤层过沟开采过程中,覆岩微裂隙发育表现为“产生–延伸和扩展–聚合成群–贯通成缝”的动态演化过程;根据微裂隙的基本发育特征及分布规律,可将发育全程划分为非连续跳跃式、连续贯通式和横向扩展式3个微裂隙发育阶段;覆岩微裂隙数量随工作面推进距离的增大而增多,非连续跳跃式和连续贯通式发育阶段呈现指数增长特征,分别累计发育微裂隙547和2 867条,覆岩微裂隙逐渐发育至地表;横向扩展式发育阶段呈线性增长特征,累计发育微裂隙11 705条,微裂隙数量随岩层高度的增大而减小;覆岩力链演化过程中,强黏性力链的破坏致使微裂隙发育,局部产生应力集中,强黏性力链拱自下而上逐渐破坏并贯通至地表,导致微裂隙延伸发育至地表形成地裂缝,力链在未贯通岩层的微裂隙两侧和尖端及地表裂缝两侧形成强力链区,微裂隙处形成弱(无)力链区。该研究成果可为陕北矿区浅埋煤层过沟开采覆岩及地表损害防控提供理论指导。 相似文献
9.
《中国煤炭地质》2015,(8)
煤层回采后覆岩破坏特征与煤层开采方法及覆岩性质相关,覆岩破坏特征主要指导水裂缝带发育高度及其形态,是顶板水害防治的关键技术参数。在分析矿井水文地质条件的基础上,采用钻孔冲洗液漏失量观测、数值模拟与经验公式3种方法综合确定了敏东一矿软弱覆岩综放开采条件下导水裂缝带发育高度,结果表明:综放开采厚度为7.7 m时,导水裂缝带发育高度为80 m。研究成果填补了我国北方大雁、扎赉诺尔、伊敏河等矿区的研究空白。通过对南一采区东西翼水文地质条件的对比分析,发现西翼水文地质条件较为复杂,提出以加强煤层顶板探放水与控制煤层开采厚度为主的防治水技术方法,并计算出工作面不同范围内的煤层开采厚度。 相似文献
10.
深部开采覆岩应力变化规律模拟实验研究 总被引：4，自引：0，他引：4
为了研究深部开采条件下覆岩结构运动所引发的动力破坏特征及巷道围岩中采动支承压力分布规律,以某矿20180工作面覆岩为研究对象,通过相似材料模拟实验,得出了深部开采条件下覆岩应力变化规律。结果表明:顶板垮落规律显著,初次来压步距较长,周期来压步距基本相似;开采过程中底板与顶板支撑压力是动态变化的,并具有同步性;随着顶板岩层高度的增加,应力集中系数逐渐减小。根据底板和顶板的应力变化规律,将底板和顶板划分为五个区域,为深部开采条件下工作面巷道超前支护,采空区瓦斯抽放及矿压控制提供可靠理论依据。 相似文献
11.
东濮凹陷北部沙三中亚段广泛发育盐岩和烃源岩,这两个看似不能共存的物质却在这里互层共生。该时期研究区沉积特征为多盐韵律与多层烃源岩互层共生、连续沉积,单个盐韵律厚度从几米到十几米,烃源岩有机质丰度高、类型好。平面上,两者在湖盆沉积沉降中心共生;垂向上,高有机质丰度、好干酪根类型与高盐度地层具有较好的对应关系。因而成为恢复古气候和古环境的重要研究对象。通过岩石学、古生物学以及Sr/Ba、B/Ga、(V+Ni+Mn)、Fe/Mn、Sr/Cu、Mg/Ca、V/(V+Ni)、稀土元素含量和氯同位素等方法对凹陷北部沙三中亚段的沉积环境进行研究。结果表明,凹陷北部沙三中亚段为深水沉积的还原环境,古盐度较高,达到半咸水-咸水沉积;微量元素和孢粉化石特征表明研究区沙三中亚段为温暖潮湿的环境。 相似文献
12.
The Importance of the Precipitation and the Susceptibility of the Slopes for the Triggering of Landslides Along the Roads 总被引：3，自引：1，他引：2
Clemente Irigaray Francisco Lamas Rachid El Hamdouni Tomás Fernández José Chacón 《Natural Hazards》2000,21(1):65-81
In order to characterise the influence of the heavyrains on the observed landslides during the 1996–1997hydrological cycle, rainfall records for the last 100years are analysed from 104 stations in easternAndalusia. Regarding the amounts of rain recordedbetween October 1996 and March 1997 in the 104stations studied, 31 presented new all-time records;15 presented values that were 80–100% of thepre-1995 record; 49 stations, 80–50%; and 9stations, < 50%. A map has been devised of thesusceptibility of the materials through which thesouth-eastern Andalusian road network crosses,together with an inventory of the damage caused byinstability phenomena on banks and cuttings of theroad network during the winter of 1996–1997. Therelationships between the rainfall during the studyperiod, the damage caused to the road network and thesusceptibility of the materials affected are analysed.The results indicate that there is a clearcorrespondence between the rainfall recorded and thesusceptibility of the materials with the inventorieddamage. It is concluded that the widespread seriousdamage caused in early 1997 to the roads andsurrounding areas in the Alpujarra region and thecoast of the Province of Granada was mainly caused bythe extraordinarily heavy rains. However, considerablyless damage was observed where the susceptibility ofthe terrain is low, thus highlighting the extremeusefulness of terrain-susceptibility maps for riskprevention and territorial planning. 相似文献
13.
郯庐断裂南段研究进展与断裂性质讨论 总被引：13，自引：3，他引：13
据1：5万区域地质调查和专题研究资料，就郯庐断裂带是否南延与消失的原因，其与大别—苏鲁造山带交截形成的假位错效应，以及与中新生代沉积盆地形成演化的关系等作了新的阐述。在此基础上，讨论了郯庐断裂带是否为巨大的左行平移断层或转换断层。认为郯庐断裂带可能是在“古郯庐带”的基础上于早侏罗世重新活动、白垩纪强烈活动的地堑型枢纽断裂带。 相似文献
14.
15.
Guboglo M. N. 《GeoJournal》1980,4(1):53-58
International unity is becoming ever stronger in this country owing to an increasing similarity in the development of the cultural environment. This comprises the provision of all the country's republics with a sufficient number of schools, theatres, and other institutions and cultural information media in accordance with the needs of the population. An important part is played by the rise in ‘the general educational level, as well as the level of professional qualifications and skills. Among all the Soviet nations and nationalities, this rise being more rapid among formerly backward peoples. Prominent among the factors of internationalization is the progressive development of the nationalities’ cultural resources, while professional culture is being increasingly brought within the reach of the masses.The implementation of the nationalities policy promotes the all-round development of all Soviet nations and nationalities, their drawing together, the upsurge of the individual capabilities of every Soviet citizen. 相似文献
16.
Dean S. Oliver 《Mathematical Geology》1998,30(7):911-933
In reservoir characterization, the covariance is often used to describe the spatial correlation and variation in rock properties or the uncertainty in rock properties. The inverse of the covariance, on the other hand, is seldom discussed in geostatistics. In this paper, I show that the inverse is required for simulation and estimation of Gaussian random fields, and that it can be identified with the differential operator in regularized inverse theory. Unfortunately, because the covariance matrix for parameters in reservoir models can be extremely large, calculation of the inverse can be a problem. In this paper, I discuss four methods of calculating the inverse of the covariance, two of which are analytical, and two of which are purely numerical. By taking advantage of the assumed stationarity of the covariance, none of the methods require inversion of the full covariance matrix. 相似文献
17.
某高速公路下伏煤矿采空区稳定性分析 总被引：10，自引：0，他引：10
在论述某高速公路下伏砦脖煤矿采空区地质、采矿和工程地质特征的基础上, 进行了稳定性数值模拟分析, 定性与定量地分析与评价了该煤矿采空区的地表变形特征及稳定性。研究结果表明: 该煤矿采空区的变形尚未完成, 对拟建的高速公路将产生很大的危害, 必须采取相应的工程治理措施。 相似文献
18.
Jiayu Rong Michael Melchin S. Henry Williams Tatyana N. Koren Jacques Verniers 《《幕》》2008,31(3):315-318
The Global Stratotype Section and Point （GSSP） for the base of the Silurian System was defined in 1985. Since that time, a number of researchers have suggested that this section has serious deficiencies for use as a GSSP. As a result, in 2000, the Subcommission on Silurian Stratigraphy （SSS） proposed undertaking a formal restu@ of this GSSP, which was subsequently approved by the International Commission of Stratigraphy （ICS）. The result of this restudy was the formal proposal that the current GSSP, at 1.6 m above the base of the Birkhill Shale, at Dob＇s Linn, Scotland, should be maintained as the same locality and stratigraphic level, but the bios- tratigraphical definition of the boundary should be revised. The previously defined, basal Silurian grapto- lite zone, the Parakidograptus acuminatus Zone, should be subdivided into a lower Akidograptus ascensus Zone and a higher E acuminatus Zone. The base of the A. ascensus Zone, marked by the first appearance of A. ascensus, should be regarded as the biostratigraphic mark for the base of the Silurian. This proposal has now been formally approved by the SSS and ICS, and ratified by International Union of Geological Sciences. This is the first GSSP to undergo formal restudy and redefini- tion, and the proposal also included a recommended procedure for restudy of GSSPs. 相似文献
19.
Deviation of the major axis of the inertia ellipsoid of the Moon from the direction toward the Earth
B. P. Kondratyev 《Astronomy Reports》2017,61(8):709-714
It is known from observations that the center of mass of the Moon does not coincide with the geometric center of its figure, and the line connecting these two centers is not aligned with the direction toward the center of the Earth, instead deviating toward the Southeast. This stationary deviation of the axis of the inertia ellipsoid of the Moon to the South of the direction toward the Earth is analyzed. A system of five linear differential equations describing the physical libration of the Moon in latitude is considered, and these equations are derived using a new vector method taking into account perturbations from the Earth and partly from the Sun. The characteristic equation of this system is obtained, and all five oscillation frequencies are found. Special attention is paid to the fifth (zero) frequency, for which the solution of the latitude libration equations are stationary and represents a previously unknown additional motion of the rotational axis of theMoon in a cone with a small opening angle. In contrast to the astronomical precession of the Earth, the rotation of the angular-velocity vector is in the positive direction (counter-clockwise), with the period T 3 = 27.32 days. On this basis, this phenomenon has been named “quasi-precession.” This quasi-precession leads to a stationary inclination of the major axis of the inertia ellipsoid of theMoon to the South (for an observer on Earth), making it possible to explain one component of the observed deviation of the center of mass of the Moon from the direction toward the Earth. The opening angle of the quasiprecession cone is approximately 0.834″. 相似文献
20.
Important tendencies in development of the world mineral-resources sector at the beginning of the 21st century were an increase in production and consumption of mineral materials differentiated by types of metals and nonmetallic mineral raw materials, by countries and regions, as well as the concentration of the production of mineral raw materials in a small number of countries, and a reduction in industrial reserves of minerals in the world economy, even at the current stage of their extraction. These tendencies should be taken into account in working out a strategy for development of the Russian mineral raw-material base. 相似文献