自然电场法与高密度电法联作在西江中下游岩溶区找水中的应用

基于溶洼区浅层岩溶地下水的渗流特性,研究富水岩溶地质结构在地下水渗流作用下引起的自然极化及由此形成的自然电场的分布特征,通过自然电场法与高密度电法联作,利用科研和中国地质调查局地质调查项目中探采结合井位的综合物探结果,探讨以自然电场法为主导、辅以高密度电法等综合物探方法,在西江中下游岩溶石山地区不同水文地质环境中寻找岩溶地下水的成功应用效果与失败的经验教训。研究结果表明,感应类电法（如瞬变电磁法、音频大地电磁测深法、地面核磁共振法、激发极化法、声频大地电场法、甚低频电磁法等）受电网、通信网络等人为电磁场干扰较严重;高密度电法抗人为电磁场干扰的能力较强,信噪比较高,但勘探深度相对较浅,且易受炭泥质灰岩、岩溶矿产等良导电岩矿体的干扰。自然电场法利用岩溶地下水运移引起的富水岩溶地质结构自然极化特征,自然电场异常与动态地下水的补给与运移状态关系较密切,自然电场法与基于探测目的体导电特性的高密度电法联作寻找溶洼区浅层地下水可起到方法互补、相互印证、提高探测分辨率与精度的作用。     

充电激发极化法在金属矿上的应用

充电激发极化法是矿山物探的一种主要方法，其兼有充电法与激发极化法的特点，可利用已有的工程，最大限度地了解地下三度空间地球物理场的分布情况，解决地质问题。概述了其理论基础和方法技术，并列举了该方法在多个金属矿上的应用实例。     

多目标规划在哈尔滨市地下水资源管理中的应用

建立了哈尔滨市地下水资源优化管理模型 ,将求解多目标最优化问题的约束法和线性加权法相结合 ,给出了一种综合解法 ,并将此法应用于所建立的水资源优化管理模型的求解。其结果可为该地区地下水资源的管理提供有参考价值的科学依据。     

桥梁沉井基础抗震性能研究现状及展望

随着国内外大跨桥梁特别是跨海桥梁建设的迅速发展,沉井基础在桥梁基础中所占的比例越来越大。虽然沉井基础作为1种刚性基础具有良好的力学性能,然而震害实践表明沉井基础在地震作用下也并非万无一失。通过分析国内外典型桥梁沉井基础的震害特征发现,沉井基础的地震破坏与桩基础有显著差异,且与埋置深度有直接关系;研究表明:地震作用下沉井基础的破坏机理及地基承载力与静力作用下明显不同,但目前在该方面的研究还较为欠缺;总结和对比了现有几种沉井基础-土相互作用研究方法,并分析了几种研究方法的优缺点和适用场合;同时也归纳和对比了各国抗震规范对桥梁沉井基础的基本规定、适用范围、计算方法和构造规定等方面的内容。最后结合现有的研究现状对沉井基础抗震性能研究的发展方向进行了展望,此外,随着我国跨海、跨江及跨库区大跨桥梁建设的发展,地震力和波浪力等多灾害因素共同作用下深水沉井基础桥梁破坏机理及设计方法的研究势在必行。     

花岗岩类土质边坡工程特性及加固方法研究

华南、华东南地区具有厚度可达上百米的花岗岩风化残积层。高等级公路、铁路的规模建设在该地区形成了大量的花岗岩类土质高边坡。深入认识该类边坡的工程特性并提出有效的针对性边坡加固方法,对该地区公路、铁路的安全建设和正常运营具有重要意义。为了更有效指导该类边坡的稳定性分析及边坡设计,本文深入调查分析了广东和广西境内4条高等级公路沿线的44处花岗岩类土质边坡特征及其稳定性,认为控制该类边坡稳定性的因素主要有:土体的均匀性、岩脉(墙)及花岗岩球状硬核的分布情况、坡体中保留的结构面是否对坡体稳定性起控制作用。继而依据这些因素把花岗岩类土质边坡划分为岩脉(墙)隔挡型边坡、网状结构型边坡、外倾结构型边坡、浮石型边坡4种类型。深入分析了每种类型边坡的坡体结构特征、稳定特性,针对性地提出了边坡稳定性分析中应重点考虑的因素。认为花岗岩类土质边坡的土质及坡体结构特征,造成了该类边坡开挖临时自稳性较好,但具有较强的开挖卸荷效应和较弱的抗冲刷能力。最后针对每种类型的花岗岩类土质边坡,提出了相应的设计方案建议。基于花岗岩类土质边坡良好的临时自稳性,认为可进行陡开挖强支护设计,同时强调逐级开挖逐级支护、加强坡面防冲刷、边坡护脚及压顶、边坡截排水等设计建议。     

Investigation on strength and stability of jointed rock mass using three‐dimensional numerical manifold method

This paper proposes a numerical model for jointed rock masses within the 3‐D numerical manifold method (NMM) framework equipped with a customized contact algorithm. The strength of rock sample containing a few sets of discontinuities is first investigated. The results of models with simple geometries are compared with the available analytical solutions to verify the developed computer code, whereas models with complex geometries are simulated to better understand the fundamental behavior and failure mechanism of jointed rock mass. Furthermore, the stability of jointed rock mass in an underground excavation is studied, where rock failure process is determined by the 3‐D NMM simulation. The simulation results provide valuable guidance on excavation process design and stabilization design in rock engineering practice. Copyright © 2012 John Wiley & Sons, Ltd.     

斑岩Cu-(Mo-Au)矿床的成矿构造环境及勘查意义

斑岩矿床是重要的矿床勘查目标。斑岩矿床的成矿构造环境研究有助于确定斑岩矿床的战略勘查方向。斑岩矿床形成的成矿构造环境包括板块汇聚边缘、大陆转换板块边界、陆内造山环境和非造山环境。本文重点对斑岩矿床在汇聚边缘和大陆转换板块边界的成矿构造环境及其勘查意义进行初步总结。构造变化对斑岩矿床的形成起到触发作用。微弱和中等程度的转换挤压应力最有利于岩浆的集聚、上升和就位。岩浆侵入可以是在广阔的转换挤压断层带内或在其周围局部呈引张的地区集中出现。对于斑岩矿床战略勘查方向而言,应注意研究区域走滑断层与侵入体的关系,加强对地表浅部喷气蚀变的识别。在我国西南地区已勘查发现的5个斑岩成矿带中,应注意沿区域走滑断裂构造方向开展找矿。从成矿构造环境与哀牢山-红河构造带对比来看,鲜水河-小江断裂带可能是西南地区新的斑岩矿床勘查区。     

An Atomic Force Microscopy study of the growth of calcite in the presence of sodium sulfate

In situ atomic force microscopy (AFM) has been used to compare the growth of pure calcite and the growth of calcite in the presence of sulfate ions from aqueous solutions at a constant value of supersaturation (S.I. = 0.89) with respect to calcite. The effect of sulfate ions on calcite growth rates is determined and a potential incorporation of sulfate ions is identified in the calcite during growth. Solutions supersaturated with respect to calcite with solution concentration ratio of one and a constant pH of 10.2, were prepared and sulfate was added as Na₂SO₄ aqueous solution. The solution composition was readjusted in order to keep the supersaturation and pH constant. PHREEQC was used to determine relevant solution concentrations. In situ AFM experiments of calcite growth were performed using a fluid cell and flowing solutions passed over a freshly cleaved calcite surface. Growth rates were determined from the closure of the rhombohedral etch pits induced by initial dissolution with pure water. The spreading rate of 2-dimensional nuclei was also measured. At low concentrations of sulfate (≤ 0.5 mM), no effect on the growth rate of the calcite was observed. At higher concentrations (2 to 3 mM) of sulfate, the growth rate increased, possibly because a higher concentration of calcium and carbonate was necessary to maintain the supersaturation constant. At much higher concentrations of additional sulfate (up to 60 mM) the growth rate of the calcite was substantially decreased, despite the fact that a further increase of calcium and carbonate was required. The morphology of 2-dimensional growth nuclei became increasingly elongated with increasing sulfate content. Measurements of step height showed that newly grown steps were approximately 1 Å higher when grown in high sulfate concentrations, compared to steps grown in sulfate-free solutions. At sulfate concentrations above 5 mM the growth mechanism changes from layer growth to surface roughening. These observations suggest that the new growth has incorporated sulfate into the calcite surface.     

中巴卫星遥感资料在土地资源遥感调查中的应用

对中巴资源卫星遥感资料的处理方法和技术流程进行了分析和讨论。并以新疆国土资源环境遥感综合调查项目的土地资源遥感调查重点县尉犁县为例，利用2000年4～9月中巴资源卫星遥感资料，计算了遥感资料在土地调查中的分类精度。     

浅谈辽河群区域对比

辽河群广布于辽东地区,为一套古元古代层状中浅变质岩系.由于原岩存在沉积相变,加之后期变质变形的改造,各地岩性组合差异较大.经多年野外实地考察,将辽河群大致划分为两区、四相段,并进行较深入的建造与改造的研究,不仅解决了辽河群层序划分和区域对比问题,而且也解决了与邻区同时代地层对比的问题.