潜孔锤反循环钻进技术在复杂地层中的试验研究

贯通式潜孔锤反循环连续取芯(样)钻进技术在钻进复杂地层时有独特效果,依托中国地调局项目,通过野外生产试验,加深了贯通式潜孔锤反循环机理的理论研究,对贯通式潜孔锤及其配套钻具的结构进行了合理的优化,大大提高了其对复杂地层的适应能力,完善了操作技术和工艺方法,使潜孔锤反循环钻进技术达到了可以广泛推广应用的水平.     

南京长江隧道三维测控系统设计

越江隧道精准化、信息化施工的基础是必须建立一套高可靠度、高精度的三维测控系统以及与之配套的科学观测程序。长江越江隧道三维测控系统如何构建是测绘界极有挑战性的一个课题,以南京长江越江隧道为例,介绍了长江越江隧道三维测控系统设计的基本方法,以及与之配套的科学观测程序。     

热力隧道下穿地面建筑物的安全评价与对策

在北京市北三环路和平东桥－太阳宫西路段热力管线工程中,依据设计热力隧道要下穿一处面积为23.4 m× 24.5 m的地表一层砖砌群房。由于隧道埋藏浅,且所处于富水粉质粘土之中,其抗扰动能力很差,常规的施工降水对强化土体效果甚微,经评价认为,普通的施工方法必然会造成很大的地表沉降而危及地表房屋安全,同时,由于土体自稳能力极低,对施工亦存在很大的安全隐患。基于此,选定在不降水的条件下,采用水平长管棚支护技术和在隧道上半断面注浆技术,实现阻水、固土、均一沉降的目的,其有效地控制了土体沉降,保证了隧道安全贯通和地表建筑的安全使用。     

云斑尖塘鳢人工育苗技术初步研究

对云斑尖塘鳢（Oxyeleotris marmoratus （Bleeker））人工育苗技术进行了初步的研究,利用燃油热水炉加温进行亲鱼越冬,采取人工辅助控温、保温的方法,配合其生态条件的调控和投喂优质饲料,培育亲鱼成熟并能自然产卵,使用人工饵料、代用饵料、生物饵料等混合饵料互相搭配组合,经过2个月左右的培育鱼苗全长达3cm左右。亲鱼具多次产卵习性,观察到一年当中最多产卵4次。利用外源激素催产率达到95．0％,自然产卵的受精率和孵化率均高于人工催产。     

河北三星口地区金多金属矿床地质特征与找矿远景浅析

三星口矿区矿点、矿种多,成矿条件良好,但矿床成因复杂。通过对三星口金多金属矿区进行深入的地质调查,从矿床地质特征、成矿物质来源、矿床成因等方面对其进行了较为系统的研究,指出本区找矿方向。     

贯通测量误差来源及质量控制技术探讨

贯通测量是矿山测量的的一项重要工作。贯通工程质量的好坏,直接关系到整个矿井的建设、生产和经济效益。本文从地面控制网误差、陀螺定向、导入高程、井下控制网误差四个大的方面对贯通测量的误差来源进行了分析,并从贯通测量的各个环节对质量控制技术进行了详细的探讨。     

On zero-thickness interface elements for diffusion problems

The present study focuses on the hydraulic behaviour of joints, and, specially, on its numerical implementation in terms of the FEM analysis using a discrete fracture flow approach. Fluid flow through discontinuities has traditionally been modelled using special elements of zero-thickness, which we can classify into single, double and triple-nodded. Single node elements are the simplest and consist of ‘line’ or ‘pipe’ elements which are superimposed onto the standard continuum mesh and that can only model the longitudinal conductivity through the discontinuity. On the other hand, some authors have included the influence of a transversal conductivity, and the subsequent localized potential drop, by using triple node interface elements. In those, the two nodes of the adjacent continuum elements represent the potentials in the pore system on each side of the interface, and a third node in the middle represents the average potential of the fluid in the channel represented by the discontinuity. Finally, double node interface elements have also been proposed, which have the advantage of making it possible to use the same FE mesh for both mechanical and flow analysis. In some cases the influence of a transversal conductivity is not considered and, therefore, although geometrically double-nodded, these elements belong to the single node type and when time comes to solve the system the two nodes must have the same potential, which can only be obtained by the ‘trick’ of prescribing the equivalence of these two d.o.f. before solving the global system of equations. This limitation may, however, be avoided by assuming that the potential in the channel is the average of the two sides of the interface. Based in this simple assumption, an alternative flow interface model has been recently developed and implemented, which preserves both longitudinal and transversal conductivities. An application example is developed and solved with the three types of interfaces described. The results offer useful information regarding the range of applicability and limitations of the new double-nodded interface element proposed. Copyright © 2004 John Wiley & Sons, Ltd.     

浅析过钻头测井面临的挑战及应对策略

本文研究了时下热门的过钻头测井技术。过钻头测井技术是21世纪以来新兴的测井方式,不同于以往的电缆测井和随钻测井。过钻头测井主要是在水平井、大斜度井段实施测量,自该技术开发以来,解决了多种技术难题。同时,过钻头测井技术也暴露出各种问题,主要就体现在(1)抗温抗压性能;(2)垂向分辨率和测量精度;(3)测量项目。本文着重介绍了这三个方面的认识与看法,提出了一些解决方案,并简要叙述了过钻头测井技术的发展方向。     

宜昌砾石层重矿物组合特征及物源示踪分析

广泛分布于宜昌至枝江—松滋一带的宜昌砾石层,对江汉平原乃至长江中游的地层划分、地貌演化、古环境变迁以及长江的形成与演化等研究具有重要意义。本研究在课题组前期研究的基础上,以本区内最具代表性的6个剖面为研究对象,对0.125~0.063mm粒级粉细砂质沉积物的重矿物特征进行了分析,结果显示宜昌代表性剖面砾石层细颗粒粉砂质沉积物的重矿物组合基本一致:锆石—绿帘石—白钛石—赤褐铁矿—钛铁矿—磁铁矿。源-汇分析表明,重矿物组成所指示的源区原岩类型除了三峡地区的还有长江三峡以西的金沙江、岷江、嘉陵江及乌江流域;经与长江及江汉平原西缘各河流的重矿物组合比较发现,宜昌砾石层的稳定重矿物组合特征与现代长江河漫滩和低矮阶地沉积物的重矿物组合一致。综合分析认为宜昌砾石层是于早更新世长江贯通三峡时形成的冲积扇,结合前人对宜昌砾石层形成时代的研究,推断三峡贯通的时间应该在1.0Ma BP左右。