A neutron activation technique for the analysis for fluorine in fluorspar samples

This article explains the results of the feasibility study about using neutron activation technique via Deferred gamma rays, to analyze the fluorine content in a sample from a fluorspar concentration plant. The theoretical responses of 12 items, constituting the samples have been analyzed. 468 reactions have been obtained from the study with the database EXFOR of these elements with neutrons from an Americium Beryllium source of 1 Ci activity.The radioactive decay of 29 products, anticipated from such an activation, has also been analyzed. From these results, a prototype for neutron activation has been designed. The different criteria of the measurement procedure to enable the activation of the fluorspar samples and to record their spectra with minimal interference from the source have been adjusted. A mathematical model of the activation response has been created and validated. The activation method to determine the fluorine content in fluorspar samples proved to be scientifically and technically feasible and verified by the results obtained.     

Plasticity model for inherently anisotropic behaviour of sands

Most deposited sands exhibit anisotropic behaviour. A plasticity model has been proposed with the capacity for simulating such anisotropic behaviour. The proposed model contains a number of coefficients of anisotropy. Methodology for determination of the coefficients of anisotropy has been discussed. Using experimental data, the coefficients of anisotropy have been determined for a number of well-known sands. Stress-dilatancy has been modelled by using the ‘normalized work’ and it has been shown that the normalized work is independent of inherent anisotropy. Finally, some reasonably close comparisons between experimental results and model simulations have been reported.     

Finite volume approach for finite strain consolidation

The paper presents the finite volume formulation and numerical solution of finite strain one‐dimensional consolidation equation. The equation used in this study utilises a nonlinear continuum representation of consolidation with varying compressibility and hydraulic conductivity and thus inherits the material and geometric nonlinearity. Time‐marching explicit scheme has been used to achieve transient solutions. The nonlinear terms have been evaluated with the known previous time step value of the independent variable, that is, void ratio. Three‐point quadratic interpolation function of Lagrangian family has been used to evaluate the face values at discrete control volumes. It has been shown that the numerical solution is stable and convergent for the general practical cases of consolidation. Performance of the numerical scheme has been evaluated by comparing the results with an analytical solution and with the piecewise piecewise‐linear finite difference numerical model. The approach seems to work well and offers excellent potential for simulating finite strain consolidation. Further, the parametric study has been performed on soft organic clays, and the influence of various parameters on the time ate consolidation characteristics of the soil is shown. Copyright © 2015 John Wiley & Sons, Ltd.     

中国地下水资源空间数据库标准化研究

结合新一轮全国地下水资源评价工作的实际情况,对评价工作涉及到的数据信息进行了综合分析,建立了数据的层次结构模型,进而提出了空间数据库图层的划分方案,结合Ma pGIS软件系统的数据格式给出了空间数据库的图层与属性的存储结构,并探讨了与空间数据库相关的数字制图等技术问题.     

Refinement of geothermobarometry for cordierite granulites

Refined geothermobarometers are presented for cordierite granulites. The refinement was achieved by using internally consistent thermodynamic datasets. Improved calibrations have been demonstrated for a number of granulite areas. Also, the usefulness of the improved geobarometer in identifying decompression paths has been discussed.     

Factor analysis for revealing hydrochemical characteristics of a watershed

R mode factor analysis was carried out on 48 groundwater samples collected from the Chitravati river basin, a typical drought-prone area of Andhra Pradesh, India. The samples were chemically analyzed by using conventional techniques (the analyzed data have been further standardized, and eigen values and eigen vectors have been computed). The data have been put into four major factors and the subsurface geology of the region has been clearly brought out by these factors. The areas prone to salinity hazard, recharging, and nonrecharging zones have been established.     

某高速公路隧道地下水控制

某高速公路是沪（上海）蓉（成都）高速路的一部分,隧洞轴线与构造线近于垂直,穿越明月峡背斜,由于部分洞段为岩溶地层,施工过程中产生了严重的突水现象,造成工程所在区域地下水位大面积下降,通过现场调查,查明了水文地质条件,明确了影响范围,提出了施工地下水控制措施,并对近期及以后需要开展的工作做了建议。     

Case-based system for slope design

A key part of slope design is the review of past examples of slopes in similar ground conditions. This paper details the development of the SlopeSafe computer program which uses case-based reasoning to formalise this process. The program, written in Visual Basic, draws on a case-base of nearly 3000 case histories of successful and failed slopes to give an indication of the likely success of a proposed slope by matching its geometry and ground conditions to the slopes held in the case-base. XML (Extensible Markup Language) has been used to store the data and a specific set of tags has been defined to provide a standard way of storing slope information. The system has been identified by practising engineers as having the potential to be a very useful design tool.     

Warning systems for natural threats

This paper is a somewhat revised version of the one previously given as a keynote lecture in the ECI Conference, ‘Geohazards: Technical, Economical and Social Consequences’. Some changes have been made to the original paper and the oral presentation: several of the figures and pictures illustrating the recent events have been eliminated, only one decision analysis example is shown and the review of literature on other warning systems has been expanded. Readers interested in the conference paper and oral presentation are referred to the website: http://services.bepress.com/eci/geohazards/     

Variable Energy Explosives for Soft Ground Blasting

A range of bulk explosives, the NOVALITE range hay been specifically developed for soft ground blasting. These explosives can be used in both wet and dry blasting conditions, range in density from 0.3-1.2 g/cc and range in VoD from 2-4.5 km/s. This range of explosives hay the potential to be tailored to ground type and is predicted to be suitable for a variety of applications which include: blasting in soft to medium overburden, coal blasting, wall control, and low vibration blasting. Trials have been conducted in several applications with encouraging results. Several cast/throw blasts have been conducted with these products partially replacing either ANFO or Heavy ANFO. The results from the blast have been equivalent in cast (per cent) and at reduced cost per unit volume. These products have also been used in presplit blasting and have again achieved equivalent or better results when compared to conventional presplit blasting at a lower cost per unit volume. This product has also been used in a vibration sensitive area replacing traditional explosive products, and generating excellent fragmentation and digging whilst maintaining vibration limits. This new range of products, NOVALITE, has shown great potential in many applications either reducing cost per unit volume, improving wall quality or improving productivity in environmentally sensitive areas.     

湘南锡矿找矿方向探讨

湘南地区蕴藏着丰富的锡矿资源,锡及锡多金属矿矿床(点)分布广泛,类型复杂,它们的形成除与花岗质侵入岩体直接相关外,同时还受到区域地层和地质构造等因素的共同制约。通过对锡矿的地质背景、分布特征、矿床特征与矿化规律、矿床成因及找矿信息和标志的研究,把湘南地区锡矿的找矿归纳为:"划带、圈区、寻体、定位"的找矿模式,不仅从宏观上提出了或解决了锡矿找矿方向的问题,而且近几年来的地质找矿工作得到了实践应用,并取得了丰硕的找矿成果。     

Multidimensional spectrum estimation for nonstationary processes

A spectrum estimation method for multidimensional nonstationary processes has been developed. The estimation method has been applied to a nonstationary two-dimensional random field. The numerical findings show that the results of the estimations are about what can be expected from a multidimensional estimation for a nonstationary process.     

土体注浆堵水的可靠性设计

建立了一套完整的土体注浆堵水可靠性设计系统。绘制了注浆堵水故障树及成功树;建立了各基本事件的极限状态方程;提出了关于单孔及多孔注浆系统的各种逻辑关系计算模型及其可靠度计算方法;定义了注浆系统的工作状态及不同注浆工程的安全等级;给出了各种注浆工程的可靠性指标;给出了注浆工程的可靠性设计方法及步骤。可用于指导现场注浆工程的设计和施工,具有较大的理论意义和广阔的应用前景。     

博兴洼陷新生代砂岩碎屑石榴石的物源示踪及对鲁西隆起的指示

鲁西隆起与临近盆地的新生代形成演化关系一直是研究的热点。以博兴凹陷为研究靶区,通过对新生代各层位碎屑石榴石的高分辨率的精确定量分析,并根据石榴石成分的专属性和含量变化,探讨了鲁西隆起与临近盆地新生代的演化历史。研究表明,博兴洼陷新生代的物源主要是来自鲁西隆起和胶东地区,其中胶东地区始终是其主要的物源。而石榴石含量的变化显示,鲁西隆起在新近纪早期大幅度隆升,推测古新世至始新世早期和始新世晚期至渐新世早期可能有两次小规模的抬升     

Rainfall thresholds for rainfall-induced landslides in Slovenia

In Slovenia, rainfall-induced landslides lead to considerable damages, even causing human losses. In order to reduce the impact of this kind of landslide, several researchers analyzed rainfall-induced landslides in this country, but to date, no rainfall thresholds have been developed for a landslide warning system at national scale. In this paper, the definition of rainfall thresholds for rainfall-induced landslides in Slovenia is presented. The thresholds have been calculated by collecting approximately 900 landslide data and the relative rainfall amounts, which have been collected from 41 rain gauges. To define the thresholds, an existing procedure characterized by a high degree of objectiveness has been used. This approach is based on a software that was developed for a test site with very different characteristics (Tuscany, central Italy). At first, a single national threshold has been defined; subsequently, the country was divided into four zones, on the basis of the major river basins. The effectiveness of the thresholds has been verified by the use of several statistical parameters and it resulted in quite good performances, even if with some uncertainties, probably due to the quality of the available data. Besides the setting of a threshold system, usable for civil protection purposes at national scale, an additional outcome of this work was the possibility of applying, with good results, a methodology defined for another region, therefore testing its degree of exportability in different settings.     

煤矿井下坑道钻机数字化设计技术

结合企业批量定制生产和产品变型开发的特点,定义了坑道钻机的数字化设计流程;提出了坑道钻机数字化设计中的数字化建模、数字化仿真和数字化管理3项关键技术。数字化建模用于建立产品三维模型和装配分析;数字化仿真用于分析产品的动态特性;数字化管理则用于管理产品设计过程及其数据。进而建立了坑道钻机数字化设计平台,包括基础、平台和应用3个层次。结合千米定向钻机开发说明了该数字化设计技术的应用。      

Flame Emission for Accurate Cesium Determination in Geostandards

Cesium values for 21 geostandards obtained by flame emission spectrometry are presented. Analytical sensitivity was separately determined for each sample by the method of standard addition to cancel effects of chemical interferences. Three types of chemical interferences have been found and their magnitude has been measured. Correction factors have been derived to improve the accuracy of analytical values reported in the literature that were obtained by calibration against a single standard.     

Searching for metals in the 1980s

The past four decades have seen an unprecedented development of metal exploration techniques because as exposed and easily exploitable mineral deposits have been used up, exploration geologists have been forced to find new ways of looking deeper into the crust.     

金属矿地震勘查方法评述

经过几十年的发展,金属矿地震勘查方法形成了以2D、3D、VSP方法为主的地震反射系列,提出了地震散射法,并取得了一定的试验效果.金属矿地震找矿的应用范围得到了扩展,不再局限于矿体本身,控矿构造、蚀变晕、重要岩性层等大型深部构造单元成为了地震间接找矿的目标体.目前,金属矿地震勘查方法,尤其是3D、VSP方法,面临着成本高、技术难度较大等问题,应进一步加强基础理论和解释方法研究,建立金属矿地震技术示范区,为推广和应用金属矿地震方法开拓思路、积累经验.