土质滑坡格构锚杆抗滑机制及受力试验研究

通过滑坡防治格构锚固大型物理模型试验,分析了土质滑坡格构锚杆体系在坡顶荷载下的变形和位移,揭示了格构锚杆的抗滑机制,探讨了锚固力与坡体位移及锚杆变形的关系,提出了极限锚固力的计算方法。结果表明：滑坡滑动时,格构梁与坡体整体发生旋转滑移,锚杆在滑面处发生了弯曲变形,处于弯曲和轴向拉伸组合变形状态;格构锚杆的抗滑作用表现为锚杆在滑面处的抗剪抗滑和锚杆格构梁的挡土阻滑;格构锚杆的极限锚固力由初始预应力、锚杆弯曲变形引起锚拉力、坡体位移引起锚拉力三部分组成,可通过公式 计算。该研究结果可为格构锚固体系的优化设计提供一定的参考。     

基于“情景-应对”的矿井水灾事故应急决策机制

为解决矿井水灾事故应急快速反应、高效决策的现场需求,针对矿井水灾事故的不确定性、复杂性和紧迫性等特点,运用多案例分析法,解析了11起典型矿井水灾事故,提出了判别“情景”和事故“情景”两个关键概念,定义了集合{突水水源,突水通道,采掘方式,出水量,淹没范围,生存空间}为矿井水灾事故的情景,并运用AHP分析法计算了6个情景要素各自的权重。确立了“情景-应对”应用在矿井水灾应急决策领域的实现途径,详细阐述了构建情景库、案例库、对策库的方法以及“情景-应对”型矿井水灾应急决策方案的生成过程,并提出了以“黄金72小时” “8天8夜”为时间节点的多阶段矿井水灾事故应急决策机制,案例推演应用表明,该应急决策机制不仅规范了事故应急流程,而且实现了精准、快速、高效的目标。      

Mineral Deposit Model of Cu–Fe–Au Skarn System in the Edongnan Region, Eastern China

Cu and Fe skarns are the world’s most abundant and largest skarn type deposits, especially in China, and Au-rich skarn deposits have received much attention in the past two decades and yet there are few papers focused on schematic mineral deposit models of Cu–Fe–Au skarn systems. Three types of Au-rich deposits are recognized in the Edongnan region, Middle–Lower Yangtze River metallogenic belt: ~140 Ma Cu–Au and Au–Cu skarn deposits and distal Au–Tl deposits; 137–148 Ma Cu–Fe; and 130–133 Ma Fe skarn deposits. The Cu–Fe skarn deposits have a greater contribution of mantle components than the Fe skarn deposits, and the hydrothermal fluids responsible for formation of the Fe skarn deposits involved a greater contribution from evaporitic sedimentary rocks compared to Cu–Fe skarn deposits. The carbonate-hosted Au–Tl deposits in the Edongnan region are interpreted as distal products of Cu–Au skarn mineralization. A new schematic mineral deposit model of the Cu–Fe–Au skarn system is proposed to illustrate the relationship between the Cu–Fe–Au skarn mineralization, the evaporitic sedimentary rocks, and distal Au–Tl deposits. This model has important implications for the exploration for carbonate–hosted Au–Tl deposits in the more distal parts of Cu–Au skarn systems, and Fe skarn deposits with the occurrence of gypsum-bearing host sedimentary rocks in the MLYRB, and possibly elsewhere.     

基于金矿规格单元数据的机器学习方法在成矿建模分析中的应用

现代金矿勘察主要是通过综合地球化学和地质测量等数字化方法对深部矿床进行研究,所需要的人力物力成本较高。而通过分析积累的金矿规格单元数据,可以建立金矿成矿情况与相关成矿元素含量之间的非线性关系,从已有的勘查数据中寻找金矿成矿的一般规律。本文基于与金矿相关的成矿元素含量数据,分别采用逻辑斯蒂回归、随机森林和决策树方法对原始数据和重采样数据进行训练,综合运用召回率、精确率和准确率对模型进行评价。通过对比发现,在训练和测试原始数据过程中,由于每组之间数据量的巨大差距,导致成矿数据被淹没;而在训练重采样数据过程中,随机森林在召回率和准确率方面均有较好的表现,分别达到了90.63%和70.78%;并最终分析了随机森林模型中不同分类边界对于金矿成矿情况预测结果的影响。利用不同的测量指标对模型进行评价分析,使模型更适用于金矿成矿预测,可有效地提高金矿勘察的效率。     

Granite is an Effective Helium Source Rock: Insights from the Helium Generation and Release Characteristics in Granites from the North Qinling Orogen,China

Global helium(He) shortage is a challenging problem; however, the types of helium source rock and the mechanisms of He generation and release therein remain still poorly understood. In this study, in order to evaluate the potential of granite as an effective helium source rock, we collected granitic samples from the North Qinling Orogen, Central China, in the south of the helium-rich Weihe Basin. The helium generation and release behaviors in granite were studied through analysis of U and Th concentrations, EMPA images, and He and Ar concentrations and isotopic ratios extracted by crushing and stepwise heating. The results indicate that Ar has a better retention and a lower mobility than He. 3 He/4 He ratios released by crushing and stepwise heating are 0.016–0.056 RA and 0.003–0.572 RA, respectively, where RA is the atmospheric 3 He/4 He of 1.4×10-6, reflecting a crustal and radiogenic source. Helium concentrations extracted by the two ways are 0.13–0.95 ucm3 STP/g and 7.82–115.62 ucm3 STP/g, respectively, suggesting that matrix-sited He accounts for more than 98% of total helium preserved in granite. In addition, the total generated He amounts in granites are calculated based on the measured U and Th concentrations in granitic samples. Dividing the preserved He quantities by the generated He amounts, it turned out that less than 10% of He produced since the formation of the granite is preserved in the rock over geological time, suggesting that more than 90% generated He can be transferred to the Weihe Basin. Temperature and fracture are the two critical factors controlling He release. Based on the relationship between He diffusivity of granites and temperature and the He closure temperatures of a variety of U-and Th-rich minerals(27–250°C), we estimate that He can be partially released out of granite at the depths 400 m and totally released at the depths 7800 m. Fractures provide effective transfer of free He from deep source rocks to shallow reservoirs. Finally, a model on granite as an effective helium source rock is established. We suggest exploring He resources in hydrocarbon basins with granitic basement(or adjacent to granite bodies), high geothermal field, and young active fractures.     

西藏樟木口岸震后滑坡灾害变形InSAR监测分析

位于中国和尼泊尔边境的西藏樟木口岸是国家一类陆路通商口岸,也是西藏最大的边贸中心口岸。2015年尼泊尔大地震之后,西藏樟木口岸因多次发生滑坡灾害,而导致口岸关闭。为了调查樟木口岸区域滑坡灾害的分布和变形情况及更好的服务于区域减灾防灾,利用InSAR技术对覆盖该区域的Sentinel-1A和ALOS-2两种卫星影像数据进行了处理,并通过分析视线向年均形变速率图,圈定了17处疑似滑坡,并对其中的5处典型滑坡进行时间序列形变特征分析,监测识别出的滑坡基本沿318国道所在一侧的波曲河左岸分布。InSAR调查结果表明受地震影响樟木地区的滑坡多分布在沿波曲河左岸的陡峭山体上,中尼公路迪斯岗至友谊桥段的古滑坡出现了局部复活的现象,同时樟木镇居民所在的城区也发育有扎美拉山危岩体崩塌滑坡灾害。      

穿透性地球化学勘查技术在隐伏砂岩型铀矿调查中的应用研究

砂岩型铀矿是铀资源的一种重要矿床类型, 该类型铀矿一般形成于中新生代盆地当中, 常以盲矿、隐伏矿产出, 勘查难度较大。我国中新生代盆地面积广大, 因此寻找砂岩型铀矿的潜力巨大。目前, 砂岩型铀矿勘查主要以物探手段为主, 地球化学勘查手段未充分发挥其作用。本文在解释穿透性地球化学勘查技术铀矿勘查原理基础上, 重点列举了近几年在我国北方大型含铀盆地开展的技术试验和示范研究案列, 在此基础上对各种穿透性地球化学勘查方法进行了梳理。认为穿透性地球化学勘查技术在砂岩型铀矿勘查中可用于圈定远景区、靶区甚至定位矿体, 可在利用地物化综合信息找砂岩型矿中发挥其应有的作用。     

廊坊市水资源现状及保护措施探讨

水资源会影响社会经济的发展,健康的水环境能够促进经济社会的良性发展。本文从廊坊市地理位置、气候特征、水资源基本状况和水资源保护工作现状等方面分析了廊坊市目前的水资源现状以及现行保护措施。结果认为,推进国家节水行动、建设水资源配置工程、推进水污染的防治、统筹修复水生态环境以及完善水资源保护与利用机制,实现水资源的可持续利用;面对水污染,要从根本上解决水污染,污水回用要合理,真正做到水资源的"开源"与"节流"。     

成熟探区资源潜力评价:以松辽盆地敖南地区为例

勘探实践证明,松辽盆地葡萄花油层成藏条件优越,具有“满凹含油”特征,是开展石油资源精细勘探的主力层系,剩余资源主要分布于成熟探区及其周边。优选位于成熟源岩区内的敖南地区作为典型刻度区,利用岩芯、测井和试油等资料,对葡萄花油层的源岩、储层及油藏进行了详细解剖和刻画,认为该区具备3个有利成藏的地质条件:①有效烃源岩控制油气分布范围;②三角洲前缘亚相薄互层砂体构成油气储集层;③砂体、构造匹配发育大面积岩性油藏。通过综合评价,确定敖南地区含油面积为256.3 km^2,采用容积法和油藏规模序列法估算该区资源量为5057.1×10^4 t,并获取运聚系数、可采系数和资源丰度等可代表资源评价的关键参数。