某露天煤矿泥岩的物理力学特性试验研究

本文对某大型露天煤矿一坑道泥岩的物理力学和物理化学特性的试验研究进行了全面的介绍。试验结果表明泥岩中含有的大量亲水性粘土矿物和少量的水稳性胶结物质及其较松弛的结构和高的含水量是泥岩物理力学特性形成和演变的基本因素。本文给出了在动态荷载作用下泥岩的强度与重复荷载次数之间的关系,泥岩在不同围压条件下的破坏机理以及泥岩强度与含水量之间的关系。最后,通过有限元的分析计算得出了均质泥岩路基与非均质(层状)泥岩路基的变形与轮压下的位移值。     

矿物成分和细观结构与岩石材料力学性质的关系

岩石材料的宏观力学性质取决于其矿物成分和细观结构。使用材料试验机,测定了岩浆岩、化学沉积岩以及碎屑沉积岩9种岩样的力学性质参数。采用X射线衍射方法,测定了相应岩样的矿物成分。使用扫描电镜,观测了相应岩样的细观结构。分析了矿物成分和细观结构分别与力学性质参数的定性关系。对各组岩样的研究分析表明:存在于颗粒边界的裂隙会显著降低岩样的抗拉强度,长石矿物是岩样脆性的主要来源,颗粒大小和面理结构会对岩石的内摩擦角造成显著的影响,细晶花岗岩中较高的方解石含量使其抗压强度和弹性模量较小,细晶花岗岩中石英含量较高,其粘聚力较大;石盐晶体的细小与紧密堆积,造成了相应岩样的膨胀或蠕变特性,有机质的存在会对岩盐的力学性能产生显著的弱化;岩样中颗粒间的弱带,会弱化岩石材料的力学性能。深灰色泥岩中石英胶结物的次生加大现象,使得深灰色泥岩的力学性能得到提高。     

矿物成分和细观结构与岩石材料力学性质的关系

岩石材料的宏观力学性质取决于其矿物成分和细观结构。使用材料试验机,测定了岩浆岩、化学沉积岩以及碎屑沉积岩9种岩样的力学性质参数。采用X射线衍射方法,测定了相应岩样的矿物成分。使用扫描电镜,观测了相应岩样的细观结构。分析了矿物成分和细观结构分别与力学性质参数的定性关系。对各组岩样的研究分析表明:存在于颗粒边界的裂隙会显著降低岩样的抗拉强度,长石矿物是岩样脆性的主要来源,颗粒大小和面理结构会对岩石的内摩擦角造成显著的影响,细晶花岗岩中较高的方解石含量使其抗压强度和弹性模量较小,细晶花岗岩中石英含量较高,其粘聚力较大;石盐晶体的细小与紧密堆积,造成了相应岩样的膨胀或蠕变特性,有机质的存在会对岩盐的力学性能产生显著的弱化;岩样中颗粒间的弱带,会弱化岩石材料的力学性能。深灰色泥岩中石英胶结物的次生加大现象,使得深灰色泥岩的力学性能得到提高。      

无定形物质对土的力学性质和结构的影响

本文研究了无定形硅、铁、铝对土的力学性质和微观结构的影响。研究结果表明,无定形物质能加强土颗粒间的连结和结构强度,含无定形物质的士通常含水量高,孔隙比大,周围环境的物理化学因素变化时,其力学性质也容易变化。     

水岩耦合下的红层软岩微观结构特征与软化机制研究

水岩长期作用下红层软岩体现出成岩作用差、易风化、易软化崩解等特点,给软岩工程设计与施工带来挑战。以滇中红层软岩地区所取泥岩试样为研究对象,首先对自然和饱水状态下岩样进行单轴和三轴压缩试验,分析水岩作用下软岩的力学特性;然后采用X射线衍射技术对不同含水状态下软岩微观结构进行对比研究;最后基于试验结果对滇中地区红层软岩遇水软化机制进行了探讨。研究结果表明:水岩作用下软岩力学性质劣化明显,岩石峰值抗压强度显著降低,岩体破坏程度提高;软岩黏土矿物颗粒吸水膨胀,微观结构由致密的团粒状转变为疏松多孔的不规则片状和鳞片状结构;伊利石等黏土矿物与水反应,产生的不均匀应力和大量微孔隙导致软岩内部结构破坏;红层软岩的遇水软化机制包括软岩矿物的溶蚀和次生作用、黏土矿物的吸水膨胀与崩解、软岩与水作用导致颗粒间胶结连结破坏等。     

东营凹陷南坡沙四上亚段滩坝储层碳酸盐胶结壳发育特征及控制因素

砂-泥岩界面是砂-泥岩互层储层水-岩相互作用的活跃地带。东营凹陷南坡沙四上亚段发育了广泛的滨浅湖滩坝沉积,储层碳酸盐胶结作用强烈,常在砂-泥岩界面富集形成致密胶结壳。综合利用钻井、物性及黏土矿物资料,结合铸体薄片观察,对储层碳酸盐胶结壳的发育规律及控制因素进行了系统的研究。碳酸盐具有多期胶结的特征,砂-泥岩接触界面处胶结物含量高,多为基底式胶结。向砂体内部胶结物含量逐渐减少,砂体中部胶结物含量少且相对稳定,以孔隙式胶结为主。半干旱碱性水体环境形成的滨浅湖泥岩中的高碳酸盐含量流体、泥岩黏土矿物转化和有机质演化析出有机-无机组分、碳酸盐胶结作用发生所需的可容空间、砂-泥岩之间的物质传递能力、砂体的厚度及岩相组合控制了储层胶结壳的发育程度。胶结壳对储层质量并非简单的"破坏性成岩作用",早期碳酸盐胶结对储层的抗压实效应以及致密层构成的异常压力系统对储层后期溶蚀孔隙的发育以及油气的充注和保存提供了有利的条件。     

中国煤矿膨胀型软岩工程地球化学研究

膨胀型软岩由于其性质的复杂和工程的严重危害性而成为当前岩石力学和工程地质学领域中最复杂的理论和工程问题之一。膨胀型软岩系指那些能与水发生物理化学反应使含水量或体积发生变化的软岩。由于不同煤矿工程的膨胀型软告形成的地质时代不同，成岩胶结程度不同，成因类型和发育规律的差异，而导致其力学化学行为也有明显差异。因此所选择的支护方式也不一样。软岩工程地球化学行为的研究，既要注意环境应力对岩石性质的影响，更要重视岩石在环境应力作用下所发生的一系列物物理化学变化对岩石自身性质影响的研究。     

碎屑岩储层碳酸盐胶结物成因研究进展

在对国内外相关文献充分调研的基础上,对碎屑岩储层碳酸盐胶结物的基本特征、物质来源、成因机制进行系统梳理和论述,总结了不同机制下碳酸盐胶结物的分布规律,并强调了几个需要注意的问题。碳酸盐胶结物具有多类型、多期次和多种分布形式的特征,其物质来源可分为内源和外源2种类型。碳酸盐胶结物可以由砂泥岩协同成岩作用、蒸发作用、生物碎屑溶解再沉淀作用、沉积速率控制作用、热对流作用、深部热流体作用等机制形成。在陆相碎屑岩储层中,砂泥岩协同成岩作用是形成碳酸盐胶结的最重要机制;但在海陆过渡相—海相地层中,除了砂泥岩协同成岩作用外,生物碎屑溶解再沉淀作用、沉积速率控制作用也是重要的碳酸盐胶结物形成机制。不同成因机制下形成的碳酸盐胶结物的矿物类型及特征、控制因素和分布规律存在差异。碳酸盐胶结物成因分析应注意利用δ13C值判断物质来源的不确定性;应重视层序地层和沉积环境在海陆过渡相—海相地层中对碳酸盐胶结的作用;应注意相同的矿物类型(如"铁白云石")或相似的分布特征(如"顶钙")成因的多解性。     

酒东坳陷下白垩统砂岩中碳酸盐胶结物特征与储层物性

碳酸盐胶结物是酒东坳陷下白垩统砂岩内一种重要的自生矿物,其对深部储层储层质量有着重要影响。本文通过薄片观察、扫描电镜、能谱分析及碳氧同位素分析,认为碳酸盐胶结物主要为铁方解石、白云石和铁白云石,并且以后者为主,其分布具有不均一性且分带性明显。碳酸盐胶结物均为成岩作用后期产生,形成该矿物所需的物质主要来源于泥岩的黏土矿物...     

长春地区白垩系泥岩地层地铁施工中地质风险及技术措施研究

通过矿物成分分析、电镜微观结构分析、物理力学性质试验、不同风化程度泥岩的膨胀和崩解试验、波速、电阻率测试等手段,对长春地区白垩系泥岩的基本地质特征进行系统研究,分析在此类地层中地铁施工可能存在的地质风险,提出相应的技术措施,为地铁建设工程问题分析及计算提供工程地质依据。     

鄂西清江偏山滑坡群易滑地层特性

二叠系大隆组和三叠系大冶组是清江流域碳酸盐岩区的易滑地层,清江中游的偏山滑坡群即为典型实例,夹泥的大冶组泥灰岩及大隆组顶部泥岩形成了滑体下部与滑带。通过现场调查、取样和室内测试,对两者的矿物和化学成分、力学性质等进行了研究分析。结果表明:大隆组顶部泥岩含胀缩性明显的蒙脱石,黏土矿物总含量为40%～75%,泥岩泥化后强度明显降低且表现出典型蠕变特性,通过流变实验得到其长期强度指标黏聚力为23kPa,摩擦角18.1; 大冶组下部泥灰岩含泥量较高,层间黏土矿物主要为伊利石和绿泥石,层面水平,顺层错动导致泥灰岩表面磨蚀及层间黏土矿物定向排列,特别是浸水后结构面强度降低明显形成易滑面加剧滑坡体的变形; 滑坡演化与清江发育之间具有相互促进作用,类似地质结构和水往复作用地带岸坡需特别重视。     

Origin of high manganese concentrations in coal mine drainage, eastern Tennessee

The origin of high dissolved manganese concentrations in slightly acidic mine runoff from a surface mine operated by the Cumberland Coal Company in eastern Tennessee was investigated. Mineralogical and chemical analyses were performed on 31 samples of sandstone, shale, coal, and mudstone from the mine to identify the sources and stratigraphic distribution of high extractable manganese contents in the spoil materials. The samples were analyzed for their bulk mineral content by X-ray diffraction, net acid-base potential, and reaction to 2 or 4 chemical extraction procedures. A limited number of samples were analyzed for petrographic characteristics, clay mineral composition by X-ray diffraction, and mineral compositions by electron microprobe. Analysis of the data and consideration of the geochemical conditions at the mine were used to identify probable sources for the high extractable manganese contents.The results indicate 2 prominent, independent sources of extractable manganese. The first source is exchangeable manganese on clay minerals (mainly illite + muscovite and chlorite) and is concentrated in shale and mudstone rock types. The second and more significant source is manganese in siderite concretions and cement, mainly in shale and mudstone. Comparison to other coal-bearing strata indicates that manganese-rich siderite is common in fresh- to brackish-water subaqueous sediments that overlie coal. This is especially the case for coals formed in wet, tropical environments.Ratios of manganese to calcium and magnesium in mine runoff suggest that manganese from siderite is the major cause of the high dissolved manganese contents. A conceptual model is developed to explain the high manganese contents of the mine runoff. Oxidation of pyrite creates mildly acidic waters that are subsequently partially neutralized by reaction with impure siderite. Solubilized manganese remains dissolved in the slightly acidic runoff water, whereas dissolved iron precipitates as ferric hydroxide or goethite. Consideration of data from other coal mining regions suggests that similar reactions involving impure siderite may be responsible for high manganese concentrations in acidic to slightly acidic mine runoff. Geochemical reaction path modeling of pyrite and impure siderite with rainwater illustrate how resulting water compositions may vary depending on pyrite to siderite ratios in spoil materials. Spoil water compositions from the Cumberland mine are largely consistent with reaction of pyrite and impure siderite in proportions observed in the sediments; however, deviations may be explained by minor mixing with waters that reacted only with impure siderite or clay mineral exchange reactions.     

改性膨胀土路堤填筑含水量优化试验研究

在控制含水量的前提下,对分别掺入不同量石灰、不同量水泥改性膨胀土试件进行强度和膨胀量试验,得到不同含 水量及不同石灰(水泥)掺量对改性膨胀土强度和膨胀性的影响,通过对实验所得数据的分析,找出含水量和掺石灰(水泥)剂 量的最佳融合点,并据此对膨胀土路堤填料的改性施工提出了一些有益的建议。     

渝东北地区龙马溪组页岩吸水特性及对其力学性质的影响

页岩中含有一定量的黏土矿物，在与水基压裂液接触后会表现出与泥岩相同的膨胀特性和强度弱化效应，进而引起套管外载增加，在页岩储层压裂过程中套管出现不同程度的变形问题。以渝东北地区龙马溪组页岩为研究对象，开展不同溶液体系下页岩的自吸、膨胀特性物理实验，分析页岩水化对其岩石力学特性的影响。结果表明:页岩吸水量与时间呈对数递增关系，在不同溶液体系中，吸水量大小表现为蒸馏水 > 地层水 > 滑溜水，含有减阻剂浓度小的滑溜水体系更利于减弱页岩的吸水能力；页岩膨胀率与时间呈逐渐增长趋势，黏土矿物含量、围压和溶液体系对页岩膨胀率影响明显，相对于黏土含量，围压对膨胀率影响更加明显，页岩在溶液体系中的膨胀性能表现为蒸馏水 > 地层水 > 滑溜水；页岩的抗压强度和弹性模量都随着水化时间的增加整体呈线性递减规律。研究结果对完井过程套管强度设计具有一定的指导意义。      

Modified Darcy''s law, Terzaghi''s effective stress principle and Fick''s law for swelling clay soils

Governing equations often used in soil mechanics and hydrology include the classical Darcy's law, Terzaghi's effective stress principle, and the classical Fick's first law. It is known that the classical forms of these relations apply only to non-swelling, granular materials. In this paper, we summarize recent generalizations of these results for swelling porous media obtained using hybrid mixture theory (HMT) by the authors. HMT is a methodical procedure for obtaining macroscopic constitutive restrictions which are thermodynamically admissible by exploiting the entropy inequality for spatially-averaged properties. HMT applied to the modeling of swelling clay particles, viewed as clusters of adsorbed water and clay minerals, produces additional terms necessary to account for the physico-chemical forces between the adsorbed water and clay minerals or, more generally, for swelling colloids. New directions for modeling consolidation of swelling clays are proposed based on our view of clay particles as a two-phase system.     

松辽盆地南部HX井上白垩统青山口组黑色泥岩的矿物组成与自生微晶石英成因

泥质岩的矿物组成和成岩作用是制约其作为CO₂地质封存的盖层封闭能力和作为页岩气储层具易压裂性质的重要原因。通过地球化学分析、X-射线衍射分析和扫描电镜观测及能谱测定,确定了松辽盆地南部HX井上白垩统青山口组泥岩的矿物组成,识别出了蒙皂石转变伊利石反应过程中形成的亚微米级自生微晶石英。研究表明：HX井上白垩统青山口组泥岩的母岩岩石类型和风化效应一致,泥岩主要由黏土矿物、钠长石和石英组成,钾长石少量;黏土矿物以伊利石/蒙皂石混层为主,其次为绿泥石;脆性矿物（钠长石、石英和钾长石）的平均质量分数为44.43%,黏土矿物平均质量分数为54.26%。蒙皂石转变伊利石反应过程中形成的亚微米级微晶石英单晶呈自形－半自形粒状,集合体呈巢状,分布于伊利石/蒙皂石混层黏土矿物的微孔隙中。以伊利石/蒙皂石混层矿物为主、且存在一定量的自生微晶石英的泥岩盖层（例如HX井青山口组泥岩）将有助于注入CO₂的长期封存。HX井青山口组泥岩中的脆性矿物含量符合工业价值页岩气的储层标准,而黏土矿物含量则相差较多。     

The Composition Microstructure and Physico-chemical Properties of Marine Soil in South China Sea

In this paper, mineral composition, microstructure, cementing materials, physico-chemical properties of marine soil are systematically investigated and chemical composition of sea water are analysed. Soil samples for this study are obtained from three areas: Weizhou Island, Hainan Island, Nansa Islands in South China Sea. Experimental results indicate that the mineral composition of marine soil mainly consists of ellite, chlorite, kaolinite and quartz, the cementing materials contains free oxides, carbonate and organic matter, the variety of microstructure is also revealed. The properties mentioned above would be the main causes of special engineering characters of marine soil.     

南海海洋土的成份结构和物化性质

本文系统地研究了海洋土的矿物组成、微观结构、胶结物质、物化性质和海水的化学成份。研究的土样采自南海三个海域:涠洲岛、南沙群岛和海南岛。研究结果表明,南海海洋土的矿物成份主要为伊利石、绿泥石、高岭石和石英;主要胶结物质是游离氧化物、碳酸盐和有机质;微观结构复杂多变。以上这些特征是形成海洋土特殊工程性质的主要原因。     

A Reconstruction and Discussion of the Effect of Diagenetic Environment on Hydrocarbon Generation Based on Diagenetic Mineral Assemblage in Mudstone

Inorganic minerals in mudstone are composed of clay minerals,carbonate and detrital minerals.Detrital minerals(such as quartz and feldspar)are mainly original deposit.However,clay minerals(kaolinite,illite,and chlorite)and carbonate(calcite and dolomite)are mostly diagenetic minerals.Furthermore,conversion of the four kinds of clay minerals are common.The formation of clay minerals and carbonate is controlled by temperature,pressure,p H,Eh and type of cations during diagenesis.Therefore mineral assemblage can indicate the characteristics and change of diagenetic environment.In addition to inorganic minerals,there are also organic matter of different sources and chemical properties in mudstone.Traditionally,it is considered that evolution of organic matter is controlled by thermal effect.Now studies show that inorganic and organic matter can interact with each other and form clay-organic complexes.This suggest that attention should be paid to the influence of diagenetic mineral assemblage and diagenetic environment on the evolution of organic matter* Samples of mudstone from 1500-4500m of the Palaeogene in the Dongying Depression,China,were collected to investigate the changes of mudstone diagenetic environment.XRD,thin section and SEM were used to detect diagenetic minerals and assemblage characteristics.Results showed that content of detrital minerals,which are floating in mud matrix or preserved as silt laminae,is basically unchanged from shallow to deep strata.Clay minerals which are gathered as argillaceous matrix or preserved as argillaceous laminae have growth and decline relation to carbonate which mainly appear as micropoikilitic ferriferous calcite and ferriferous dolomite.All these characteristics indicate that detrital minerals are exogenetic,whereas carbonate is diagenetic minerals.Based on the SEM analysis of the clay minerals,it was found that smectite present honeycomb and reticulate structure,while illite present filiform and schistose structure and there are growth and decline relationship between them.Nevertheless,hexagonal tabular and stratified kaolinite has the highest content from 2400m to3300m.Rosette and stratified chlorite shows increase trend when the burial depth is deeper than 3300m.These characteristics indicated that clay minerals are diagenetic minerals and there are conversions among the four types.Therefore form shallow to deep,three diagenetic mineral assemblage zones can be divided based on the characteristics of carbonate and clay minerals in mudstone.Namely,smectite+illite/smectite zone in the depth of 2000-2500m;kaolinite+illite/smectite zone in the depth of 2500-3300m and illite+chlorite+carbonate zone below 3300m.Previous studies showed that kaolinite is stable under acidic conditions,while other clay minerals and carbonate are stable under alkaline conditions.Hence according to mineral assemblages feature,it was inferred that diagenetic environment of mudstonehasundergonethechangeof alkaline-acid-alkaline.For the organic matter with different chemical properties in mudstone,the hydrocarbon generation will be different in the acidic and alkaline diagenetic environment even if the conditions of temperature and pressure are the same.Therefore,for hydrocarbon generation we should not only focus on thermal effect,but also pay more attention to the differences of diagenetic environment which have great significance for the understanding of hydrocarbon generation,hydrocarbon expulsion and reservoir formation in mudstone.     

高掺量粉煤灰固结材料的矿物组成及微观结构研究

采用化学成分、X衍射和电子显微镜分析等方法研究了高掺量粉煤灰固结材料的矿物组成及微观结构。结果表明 ,其矿物组成主要是 3Al2 O3 ·2SiO2 和硅铝酸盐的胶凝物相 ,具有较大孔径的多孔结构特征 ,与水泥混凝土的矿物组成和微观结构有较大不同 ;粉煤灰的掺量、养护龄期对水化产物的生成量有直接影响 ;固结剂掺量大于 2 0 %时 ,粉煤灰和固结剂全部反应形成多孔状的胶凝体水化产物