矿井涌水量的预测方法

矿井涌水量的预测方法,经实践认为,水文地质比拟法与相关分析法计算简便,其结果也较符合实际。但使用时,要求未采矿山与已采矿山的水文地质条件必须相似.     

海南保亭县甘什岭滑坡成因分析及稳定性评价

简要介绍了保亭县甘什岭滑坡的形态、地层岩性、水文地质环境条件及地质构造等情况,分析了该滑坡的形成原因,并对其进行稳定性评价和危险性分析,稳定计算方法选用剩余推力传递法对滑坡稳定性加以试算,其计算结果与滑坡实际情况基本吻合。通过以上分析,可得以下结论:当滑坡在天然状态下时,稳定系数K的范围在1.17~1.26之间,此时滑坡处于稳定状态;当滑坡在饱水状态下时,稳定系数K的范围在0.99~1.03之间,此时滑坡处于滑移状态。     

应用水化学动力学法计算磐石地下水系统渗透系数

应用水化学动力学法求水文地质参数是将化学热力学、化学动力学与地下水动力学理论相结合,计算水中矿物的离子活度αi和饱和指数βj,建立渗透系数(K)与αi、βj之间的数学关系式,并结合水文地质条件,求渗透系数(K)。磐石市地下水中Ca2+、Mg2+、SO24-和Cl-活度及其相应矿物方解石、白云石、石膏和石盐的饱和指数的变化趋势与渗流场特征一致。将计算区划分成6个区,计算出αi、βj及化学反应速率常数kj,求得各分区的K值。计算区K值变化在10.78~26.91m/d之间,与抽水试验法求得的渗透系数值吻合良好。利用水化学动力学法计算水文地质参数不但可以弥补局部地区由于缺乏抽水试验资料而难以确定水文地质参数的困难,同时可减少抽水试验工作,获得可观的经济效益。     

地面沉降对含水层参数及给水能力的影响研究

地面沉降主要由深层地下水开采造成,含水层的压缩释水是深层地下水开采量主要构成来源,同时随其压缩变形孔隙比减小造成储水系数、渗透系数的减小,对弱透水层非弹性释水量、越流补给量造成影响。地面沉降过程中的水文地质参数非线性变化及对承压含水层系统的反馈作用也成为水文地质领域的前沿问题。为对地下水开采量、沉降量、地质参数变化以及给水能力变化之间的关系做一个较为定量定性的探究,以含水层压缩过程中的物理机制为依据,并基于沧州地区深层承压含水层的地下水位变化过程和水文地质参数,采用数学手段构建储水系数和渗透系数变化的一维非线性沉降模型。模拟结果显示随承压水头下降,储水系数最高可减小77%,含水层系统的给水能力和储水能力会随压缩变形减小50%甚至更多。研究成果为深入认识水文地质参数与应力变化相关关系、科学评价承压含水层地下水储水调节能力有重要借鉴意义。     

基于不同孔径钻孔抽水试验求参对比分析

抽水试验是确定含水层水文地质参数,了解水文地质条件的主要方法。水文地质参数计算的精度直接关系到地下水资源评价精度和对区域水文地质条件的认识程度。基于野外抽水试验数据,通过裘布依稳定井流公式法和含水层试验软件Aquifer test计算水文地质参数,将计算结果作比较,以期得到更加精确的水文地质参数。虽然裘布依稳定井流法计算简便,但对水文地质条件概化处理,使得参数计算结果与实际值相差较大;而Aquifer test软件基于严谨的非稳定流理论数学模型,求参准确性相对较高,操作方法简捷。     

改进层次分析法在矿井水文地质类型划分中的应用

矿井水文地质类型划分是矿井水文地质工作的一项重要内容,对分析充水条件,评价水害威胁程度,指导矿井防治水工作具有重要意义。引进最优传递矩阵对层次分析法进行改进,将改进的层次分析法应用到水文地质类型划分中。以内蒙古呼吉尔特矿区4对生产矿井为例,在分析水文地质条件的基础上,建立了矿井水文地质类型划分的评价指标体系,利用改进的层次分析法,计算各项影响因素的权重值,建立数学模型计算每个矿井综合得分Z值,根据计算结果,呼吉尔特4对生产矿井水文地质条件均为复杂型。      

区域平均变值给水度的确定

给水度是水文地质参数中的一个重要参数,对于地下水资源计算、农田排水设施的设计都具有非常重要的作用。本文提出了变值给水度与常值给水度之间的差别,并对其确定方法作了探讨。在研究了变值给水度的基础上,对生产应用上具有重要意义的区域变值给水度的确定方法进行了论述,并指出其对于生产应用的可行性。     

运用电测深方法研究水文地质参数

本文根据淮北宿南矿区的电测深及水文地质资料,利用含水层的横向电阻(经地下水电阻率影响因素校正)与含水层导水系数的相关关系?)计算出含水层各测点的水文地质参数,并且绘制出矿区水文地质参数等值线图,提高水文电法勘探的地质效果。     

用地下水化学动力学方法计算出的水文地质参数来定量评价水文地质条件——以太原三给地垒及周围地区为例

作者根据研究区内剖分获得429个结点的原始资料，分别计算出K，T,u,U,t等5个水文地质参数各429个，利用计算结果，编制K值和T值分区图及地下水循环条件图，对研究区水文地质条件进行了定量评价，该方法为其它岩溶区水文地质条件进行定量评价提供了一条有效的新途径。     

梯度法在水文地质参数估值中的应用

根据地下水的抽水试验求含水层的导水系数和储水系数时,传统的计算方法是配线法和直线图解法。这两种方法比较繁琐,且人为误差较大。本文运用数学模型的最优化方法即梯度法,并借助于计算机编程,实现了水文地质参数的数值求解。计算结果能消除人为误差,准确反映含水层的参数特征。     

Study on ecological and economic effects of land and water resources allocation in Sanjiang Plain

The pattern of groundwater usage and industrial development in the Sanjiang Plain remains a concern of Chinese government. In accordance with the Water Conservancy Planning of the Sanjiang Plain, this paper presents a Sanjiang Plain resources allocation model which is established to be used in controlling water, land, ecology and economy in consideration of 50%-level and 75%-level years, planting structure adjustment, industry development by 2020, and different transit water exploitation schemes. Lingo10 global optimization has been adopted in solving the model. The results show that by 2020 the output of three industries will increase to a certain degree, the grain yields will satisfy state demand, and regional service value will decrease dramatically. Such results provide theoretical basis and practical significance for instructing the development and exploitation of the Sanjiang Plain.     

降水和开采变化对石家庄地下水流场影响强度

为能精确识别降水和开采对石家庄地下水流场影响强度,应用小波变换和相关分析等研究方法,对区域平均地下水位、地下水降落漏斗面积及中心水位与降水和开采变化之间的互动特征进行了研究。结果表明:① 1961—1973年期间,平均地下水位随降水量增大呈幂函数递减趋势;1974—2010年期间,降水量每减小100 mm,漏斗中心水位下降速率增大7.35 m,平均地下水位下降速率增大2.15 m;② 1961—1973年期间,开采量每增加1亿m3,平均地下水位下降0.28 m,漏斗面积扩大11.74 km2,中心水位下降0.52 m,1974年以来累计超采量每增加1亿m3,漏斗面积增幅1.52 km2,中心水位降幅0.18 m;③ 降水量每减小100 mm,降水贡献度减弱3.0%,人类开采影响强度增大2.76%。     

The Middle–Late Jurassic forced regression and disconformity in central Portugal: eustatic, tectonic and climatic effects on a carbonate ramp system

Abstract Successions across the Middle–Upper Jurassic disconformity in the Lusitanian Basin (west‐central Portugal) are highly varied, and were probably developed on a large westward‐inclined hangingwall of a half‐graben. The disconformity is preceded by a complex forced regression showing marked variations down the ramp, and provides an example of the effects of rapid, relative sea‐level falls on carbonate ramp systems. In the east, Middle Jurassic inner ramp carbonates (‘Candeeiros’ facies) are capped by a palaeokarstic surface veneered by ferruginous clays or thick calcretes. In the west, mid‐outer ramp marls and limestones (‘Brenha’ facies) are terminated by two contrasting successions: (1) a sharp‐based carbonate sandbody capped by a minor erosion surface, overlain by interbedded marine–lagoonal–deltaic deposits with further minor erosion/exposure surfaces; (2) a brachiopod‐rich limestone with a minor irregular surface, overlain by marls, lignitic marls with marine and reworked non‐marine fossils and charophytic limestones, with further minor irregular surfaces and capped by a higher relief ferruginous erosional surface. The age ranges from Late Bathonian in the east to Late Callovian in the west. This disconformity assemblage is succeeded by widespread lacustrine–lagoonal limestones with microbial laminites and evaporites (‘Cabaços’ facies), attributed to the Middle Oxfordian. Over the whole basin, increasingly marine facies were deposited afterwards. In Middle Jurassic inner‐ramp zones in the east, the overall regression is marked by a major exposure surface overlain by continental sediments. In Middle Jurassic outer‐ramp zones to the west, the regression is represented initially by open‐marine successions followed by either a sharp marine erosion surface overlain by a complex sandbody or minor discontinuities and marginal‐marine deposits, in both cases capped by the major lowstand surface. Reflooding led to a complex pattern of depositional conditions throughout the basin, from freshwater and brackish lagoonal to marginal‐ and shallow‐marine settings. Additional complications were produced by possible tilting of the hangingwall of the half‐graben, the input of siliciclastics from westerly sources and climate change from humid to more seasonally semi‐arid conditions. The Middle–Late Jurassic sea‐level fall in the Lusitanian Basin is also recorded elsewhere within the Iberian and other peri‐Atlantic regions and matches a transgressive to regressive change in eustatic sea‐level curves, indicating that it is related in part to a global event.     

单个裂隙中油运移实验及特征分析

利用狭窄平行板裂隙模型来模拟和分析单个裂隙内油运移的过程。实验中采用表面起伏的玻璃板制作平行板裂隙模型,通过改变水中蔗糖的浓度控制两相流体间的密度差,来分析不同密度差和注入速率条件下油的运移过程和特征。观察发现,油在饱含水的狭窄裂隙空间内的运移特征与在孔隙介质中的运移有相似之处:运移的路径只占通道的一部分,都具有不规则的分形特征,也可形成活塞式、指进式和路径式等模式。而这些模式的形成也同样受各种因素的影响。利用孔隙介质中油运移实验结果总结出来的、以Bo数和Ca数为纵横坐标运移相图完全可以用来表征单个裂隙中油的运移模式。     

Late Devensian river and floodplain dynamics and related environmental change in northwest Europe,with particular reference to a site at Woolhampton,Berkshire, England

Marked fluctuations in Late-glacial climate are correlated with significant changes in river behaviour and floodplain environment across much of northwest Europe. Evidence from a new site in the Kennet Valley provides a rare comprehensive picture of varying fluvial regime and local vegetation during this interval. Chronological control for the site is provided by biostratigraphical and morphostratigraphical correlations with other sites in the region, and by radiocarbon dating of carefully selected material. Preservation of the sedimentary sequence was facilitated by its occurrence within a large depression in the underlying bedrock. The origin of this depression is uncertain, perhaps reflecting subsidence or scour. Following the Last Glacial Maximum, a nival regime braided river dominated by floods deposited sandy gravels under stadial conditions. A large channel infilled by fine sediments during the latter part of the Windermere Interstadial indicates a fall in flow competence at a time of increased floodplain vegetation, most notably the appearance of tree birch. Variations in sediments and vegetation suggest fluctuations in the floodplain environment, reflecting complex vegetation dynamics and possibly climate forcing. During the Loch Lomond/Younger Dryas Stadial, a nival, braided regime was re-established, accompanied by the disappearance of tree birch.     

贵州省岩溶石漠化地区生态服务价值损失评估

构建了适合岩溶石漠化地区的生态价值损失评估指标体系,基于遥感资料、典型样点调查数据及社会公共数据,采用将物质量转化为价值量的方法,估算和评价了贵州省石漠化地区的有机质生产、固碳释氧、水土保持、营养物质积累、生物多样性保育及景观游憩6项核心生态价值的损失。结果表明:(1)不同石漠化等级单位价值量分别为潜在12483.88元/(hm2?a)、轻度7425.97元/(hm2?a)、中度6557.83元/(hm2?a)、重度4414.06元/(hm2?a)、极重度3755.07元/(hm2?a)。(2)贵州省岩溶石漠化地区生态系统服务的总价值损失量为210.85亿元/a,其中潜在、轻度、中度、重度、极重度的损失量分别为8.72亿元/a,59.43亿元/a,101.15亿元/a,47.89亿元/a和5.66亿元/a。(3)空间分布上,各州市生态价值损失量变幅在12.92~56.57亿元/a之间,生态价值损失量大小依次为毕节地区>黔南州>遵义市>黔西南州>安顺市>铜仁地区>六盘水市>黔东南州。      

Folding of passive layers and forms of minor structures near terminations of blind thrust faults—application to the central Appalachian blind thrust

The existence of detachment surfaces or décollement zones beneath folded rocks of the Valley and Ridge and Plateau provinces of the Appalachians has been recognized as an important condition of folding. Large folds at the border between the two provinces resulted primarily from repetition of strata by thrusting of blocks over ramp faults that connect detachement surfaces at different horizons. Some investigators have suggested that folds in the Plateau province of Pennsylvania were produced by splay faults arising from detachment surfaces, but field observations and theoretical analyses by Sherwin and by Wiltschko & Chapple suggest that the folds are a result of buckling of multilayered rocks above a décollement. An exception may be the Burning Springs anticline in West Virginia, which appears to have formed at the termination of a detachment surface.Investigation of the translation of an homogenous, viscous material above a flat detachment surface that terminates laterally indicates that the termination produces a broad, low-amplitude anticline in passive layering as a result of thickening induced by a gradient of shear stresses in the vertical direction. This thickening above the termination of a detachment is a mechanism of folding. If the viscous fluid contained mechanical layering, the fold would become amplified by buckling. Computations of stresses in the material indicate that minor faults should be generated first near the termination of the flat detachment surface. The Burning Springs anticline probably was initiated by termination of a detachment surface and subsequently amplified by buckling.     

Changes in the indices of the strength and strain properties of loamy soils under the influence of fermentation and denitrification

The results of studying the influence of fermenting and denitrifying bacteria on some properties of loamy soils are presented. After the treatment of loamy soils by the bacteria, there was a tendency towards a decrease in soil densities, an increase in porosity, a decrease in the angle of internal friction by 10–40% and in the angle of coherence by 25–40%, along with a decrease in the strain modulus by 35–65% in the load range of 0.1–0.2 MPa. Data are analyzed, and microbiological processes that might cause such changes in the soil are indicated.     

Reducing ground vibrations caused by underground blasts in LKAB Malmberget mine

Due to the large-scale sub-level caving in Malmberget mine and the short distance between the mine and Malmberget town, the ground vibrations in the town have reached a high level since the year 2001 when large scale caving mining started. In order to control and reduce the high vibrations, LKAB launched a research project on active reduction of vibrations in Malmberget by using the wave interference or wave superposition method with electronic detonators. By means of this method, the vertical vibrations were reduced by 10% and the total vibration time for a ring blast was reduced by 80% according to five ring tests in the mine. For a further reduction of the vibrations, a second method, named changing initiation sequence in ring blasts, was developed on the basis of stress wave theory and the geographic conditions of the town and the mine. The second method has so far been applied in all of the drifts near the town, and the vibrations measured at the town show that the vertical vibrations caused by production blasts in the mine have been reduced by more than 31% on average. In addition, a third method, dividing a ring into two parts during blasting, was developed and used to reduce the ground vibrations from a number of very large rings in the mine. The results indicate that the vibrations have been reduced by more than 33%, and a more interesting and surprising result is that ore extraction has been increased by the third method.     

Centrifuge modelling of laccolith intrusion

Laccolith intrusion has been investigated by centrifuge modelling. Silicone putty, representing magma with Bingham rheology, is intruded by overburden pressure through a circular conduit into a stack of paraffin wax layers, which represent sedimentary strata. The model intrusions evolve through a sequence of geometric forms similar to those exhibited by natural laccoliths; the results are also in accord with published mathematical analyses of laccolith formation. The model magma first flows laterally between overburden layers to form a sill. As the sill increases in area, the cover strata are arched upwards into a sinusoidal, ‘bending’ form. Subsequently, the overburden fails abruptly by kinking above the periphery of the intrusion, and the form changes to a cupola separated from surrounding horizontal strata by a sharp inflection in the layering. Finally, strata on the flanks of the cupola undergo a second episode of localized failure. The top of the dome becomes flat, and the dipping flanks become a monoclinal flexure surrounding this ‘kink’ form.A number of variables influence this evolution. Increased overburden strength, thickness of overburden strata, and total thickness of overburden all prolong the bending form to larger intrusion size, delay the localized failure which marks the cupola and kink stages, and reduce the aspect ratio of the intrusion at all stages. Effectively bonded overburden interfaces have a similar effect, but interfaces with sharply defined yield strengths enhance development of the monoclinal flexure. Magmatic driving pressure affects the rate of intrusion, but not the evolution of its form. Intrusion rate is also influenced by magma flow properties, and probably by the form of the feeder conduit. The range of final forms preserved by natural laccoliths probably results from competition between rate of intrusion, controlled by driving pressure and conduit geometry, and rate of chilling of magma in the laccoliths. The model laccoliths form in times that scale to between one and a few tens of years, in agreement with available estimates for natural laccoliths.