赤泥库大坝渗漏分析及灌浆处理技术          下载免费PDF全文

黄全海  赵尊亭  王利芳 《探矿工程》2015,42(11):66-69，79

由于施工质量问题,洛阳一个赤泥库大坝在试运行中发生大面积渗漏及管涌。在对渗漏原因进行分析的基础上实施的在坝内坡增设土工膜、坝轴线上游增设帷幕灌浆防渗墙、坝体下游坡面增设排渗沟和排水棱体等抢险加固措施,有效地解决了坝体渗漏问题。在灌浆处理过程中,针对筑坝材料的复杂性和不均匀性,通过施工前的灌浆试验,取得了适合本场地条件的钻孔施工工艺参数及灌浆方式、灌浆压力、灌浆段确定、水灰比比级等施工技术参数,确保了灌浆处理的效果。  相似文献   

新疆坡北矿区ZK2-6孔钻探施工技术          下载免费PDF全文

盖志鹏  罗刚  贾宏福  王磊  付兆友 《探矿工程》2015,42(8):30-34

新疆坡北矿区ZK2-6孔施工中遇到多层蚀变带,最长连续强蚀变带达30 m,在以往施工过程中,因卤水配制的泥浆性能难以保证,不利于孔壁的稳定,导致在钻进过程中,孔壁剥落超径、断钻杆事故频发。钻杆断开后,由于孔壁坍塌,找不到事故头,从而导致钻孔报废。针对蚀变、破碎地层钻进易发生的孔壁坍塌、超径、掉块及卤水泥浆性能难以保证等问题,开展相关研究,提出相应的技术措施,圆满完成了坡北工区ZK2-6孔的钻探施工。  相似文献   

新疆独山子泥火山沉积物及孔隙水的地球化学特征与流体来源     

黄华谷  李牛  王钦贤  陈多福 《大地构造与成矿学》2015,(2)

对陆地泥火山流体来源及其向地表渗漏过程中的改造作用开展研究,有利于加深理解泥火山释放甲烷的碳排放过程。新疆准噶尔盆地南缘独山子泥火山柱状沉积物和地表沉积物的矿物和元素组成,以及沉积物孔隙水离子组成等的分析结果显示,泥火山沉积物孔隙水Na+和Cl–间具有很好的正相关性,具有比海水高的Na+/Cl–和Li+/Cl–值、低的K+/Cl–和Mg2+/Cl–。泥火山沉积物与围岩相比,富集伊利石、绿泥石和方解石,缺少蒙脱石,富集Ca、亏损Si,这些变化主要与黏土矿物的脱水转变有关。表明泥火山流体主要来源于深部低盐度沉积物孔隙水,但经历了地表的蒸发作用,并混合了大气降水。  相似文献   

Mixed sand–mud bedforms produced by transient turbulent flows in the fringe of submarine fans: Indicators of flow transformation     

Megan L. Baker  Jaco H. Baas 《Sedimentology》2020,67(5):2645-2671

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GRACE时变信号恢复方法对比分析     

刘冰石  邹贤才 《大地测量与地球动力学》2019,39(2):204-209

针对利用GRACE重力数据反演地表质量变化过程中产生的时变信号削弱和泄露现象，分别采用尺度因子法和迭代恢复法对信号进行恢复，并选用CSR Mascon产品从时间序列变化和空间分布两个角度对两种恢复方法的效果进行对比分析。结果表明：1)尺度因子法虽实现上较为简单，但其计算结果完全依赖于所选的先验模型，当所选模型的可靠性较差时，会影响到GRACE反演结果的可靠性。2)迭代恢复法的恢复过程仅受GRACE原始观测值的约束，能较好地恢复研究区域的长期趋势信号和周期信号，但在部分区域可能存在信号过量恢复的现象。建议采用迭代恢复法进行GRACE时变信号恢复。  相似文献   

The 2019 Brumadinho tailings dam collapse: Possible cause and impacts of the worst human and environmental disaster in Brazil     

《International Journal of Applied Earth Observation and Geoinformation》2020

On 25th January 2019, the tailings dam of the Brumadinho iron mine operated by Vale S/A failed catastrophically. The death toll stood at 259 and 11 people remained missing as of January 2020. This tragedy occurred three years after Mariana’s tailings dam rupture – the most significant tailing dam disaster in Brazilian history. Thus far, a systematic investigation on the cause and effect of the failure has yet to be conducted. Here, we use satellite-driven soil moisture index, multispectral high-resolution imagery and Interferometric Synthetic Aperture Radar (InSAR) products to assess pre-disaster scenarios and the direct causes of the tailings dam collapse. A decreasing trend in the moisture content at the surface and the full evanescence of pond water through time (2011–2019) suggest that the water was gradually penetrating the fill downwards and caused the seepage erosion, saturating the tailings dam. Large-scale slumping of the dam (extensional failure) upon the rupture indicates that the materials of the fill were already saturated. InSAR measurements reveal a dramatic, up to 30 cm subsidence in the dam (at the rear part) within the past 12 months before the dam collapse, signifying that the sediments had been removed from the fill. Although the information on the resistance level of the tailings dam to infiltrations is not available, these pieces of evidence collectively indicate that the seepage erosion (piping) is the primary cause for the chronic weakening of the structure and, hence, the internal “liquefaction” condition. Upon the collapse, the fully saturated mud tailings flowed down the gentle slope area (3.13 × 10⁶ m²), where 73 % were originally covered by tree, grass or agricultural tracts. The toxic mud eventually reached the Paraopeba River after travelling 10 km, abruptly increasing the suspended particulate matter (SPM) concentration and the toxic chemical elements in the river, immediately affecting the local livelihoods that depend on its water. The Paraopeba River is a major tributary of the San Francisco River, the second-longest river in Brazil reaching the Atlantic Ocean. We anticipate that the environmental repercussions of this toxic seepage will be felt throughout the entire basin, especially riverine communities located downstream.  相似文献   

秦岭造山带多金属矿普查复杂地层护壁堵漏技术          下载免费PDF全文

柳硕林  韩明耀 《探矿工程》2020,47(1):43-47

秦岭造山带多金属矿普查项目钻探施工过程中钻遇多种复杂地层，垮塌、缩径、漏失等复杂情况频发，严重影响了施工效率。分别采用了植物胶钙处理钻井液、聚乙烯醇无固相钻井液等进行护壁工作，结合不同漏失情况分别实施了随钻堵漏、凝胶堵漏等技术措施，取得了良好的使用效果。  相似文献   

基于高导热材料填充漏失构造的深井换热器性能分析   总被引：1，自引：0，他引：1  

卜宪标  蒋坤卿  李华山  王令宝 《地质学报》2020,94(7):2139-2146

地热供暖可有效缓解北方雾霾天气。干热岩虽然储量丰富，但增强型地热技术由于开发费用较高，裂隙控制以及避免诱发地震的技术尚不成熟，现阶段还不能商业化应用。水热型地热开发技术虽较成熟，但受资源条件的限制，开发规模较小。对于大多地区，受地质构造和资源禀赋的控制，单井产水量较低或者回灌难，开发经济效益较差。深井换热器（DBHE）技术是开采地热水低产区或回灌难地区热能的有效方式，但受制于岩石导热系数低，单井输出功率小，投资回收期长。为提高DBHE的输出功率，本文提出了增强型深井换热器（EDBHE），通过主动将高导热性能的复合填充剂流进漏失构造的方式提高岩石的导热性能，通过调节回压、密度和黏度来控制漏失量。研究结果表明，单井EDBHE十个采暖季的平均取热功率为1002. 34 kW，是DBHE(424. 45 kW)的2. 36倍。而双井EDBHE十个采暖季的平均取热功率更是达到了27501. 61 kW，且热输出稳定，每年的衰减率0. 95%。EDBHE技术有效利用了出水量低或回灌难的水热型热储，大幅提高了其出力，扩大了地热供暖的应用范围。  相似文献   

Formation of mud clast breccias and the process of sedimentary autobrecciation in the hominin-bearing (Homo naledi) Rising Star Cave system,South Africa     

Jelle P. Wiersma  Eric M. Roberts  Paul H. G. M. Dirks 《Sedimentology》2020,67(2):897-919

Unconsolidated mud clast breccia facies in the hominin-bearing (Homo naledi) Rising Star Cave, Cradle of Humankind, South Africa, are interpreted to have formed through a process termed sedimentary autobrecciation in this study. This process, by which most of the angular mud clast breccia deposits are thought to have formed autochthonously to para-autochthonously via a combination of erosion, desiccation, diagenesis and microbial alteration of laminated mud deposits, is thought to have taken place under relatively dry (i.e. non-flooded) conditions inside the cave. Subsequently, gravitational slumping and collapse was the dominant mechanism that produced the mud clast breccia deposits, which commonly accumulate into debris aprons. The mud clast breccia is typically associated with (micro) mammal fossils and is a common facies throughout the cave system, occurring in lithified and unlithified form. This facies has not been described from other cave localities in the Cradle of Humankind. Additionally, sedimentary autobrecciation took place during the deposition of some of the fossils within the Rising Star Cave, including the abundant Homo naledi skeletal remains found in the Dinaledi Subsystem. Reworking of the mud clast breccia deposits occurs in some chambers as they slump towards floor drains, resulting in the repositioning of fossils embedded in the breccias as evidenced by cross-cutting manganese staining lines on some Homo naledi fossil remains. The formation of the unlithified mud clast breccia deposits is a slow process, with first order formation rates estimated to be ca 8 × 10⁻⁴ mm year⁻¹. The slow formation of the unlithified mud clast breccia facies sediments and lack of laminated mud facies within these deposits, indicates that conditions in the Dinaledi Chamber were probably stable and dry for at least the last ca 300 ka, meaning that this study excludes Homo naledi being actively transported by fluvial mechanisms during the time their remains entered the cave.  相似文献   

尼日尔三角洲东部深水区构造特征及其形成机理     

赵江  王秋良  卢圣力  付博  杜峰 《大地测量与地球动力学》2019,39(7):691-695

研究尼日尔三角洲东部深水区块发现，整个盆地从陆向洋具有3个大的构造分区：伸展拉张区、过渡区和挤压逆冲区。伸展区以大型同沉积断层伴生大量滚动背斜构造为特征，过渡区发育大量泥底辟构造，挤压区以复杂的逆冲叠瓦构造为主。通过分析形成机理，揭示东部深水转换带上M研究区构造特征，按构造的演化特征将该区构造分为泥底辟型、冲断-泥底辟混合型、逆冲型3种类型，提出研究区内的圈闭主要以构造-岩性圈闭为主，为尼日尔三角洲盆地深水勘探提供新的理论指导。  相似文献