Stress–Strain Model for Carbonate Rocks Based on Haldane’s Distribution Function

Summary. This paper presents a model created by the author to predict stress–strain relationships for weak to strong carbonate rocks (σ_c < 100 MPa) exhibiting axial strains up to 1%. The stress–strain model based on Haldane’s distribution function (Haldane, 1919) relates the axial stress (or normalized axial stress) to the square of an exponential function where the exponent is axial strain. To obtain accurate stress–strain relationship over the whole pre-failure strain with the proposed stress–strain model, it is necessary to have only one datum point (peak axial stress and maximum axial strain at this peak stress). It is shown that the stress–strain relationships observed in laboratory compression tests on samples collected from six carbonate rock formations (chalk, dolomites and limestones) from different parts of Israel, agree well with the stress–strain prediction model proposed by the author.     

A new rock mass classification for Coal Measures Rocks

This paper examines a new rock mass classification system (RMCR) for Coal Measures Rocks which is based on extensive laboratory testing results. The new system has been developed using 12 parameters which consist of mineral content index, uniaxial compressive strength, uniaxial tensile strength, Young's modulus of elasticity, shear strength, cohesion of rocks, angle of internal friction, point load index, cone indenter index, Cerchar index, Shore schleroscope hardness and specific energy index. The RMCR value was obtained by a number of laboratory and in situ testing results which were obtained from the coal site. The objective of the RMCR is to estimate the rock mass properties for engineering purposes.     

海堤下软基超孔隙水压力值的修正方法

当潮位的涨落引起上部堆载容重变化时，海堤下软基的超孔隙水压力将随潮位呈周期性变化．为了解软基的固结情况，必须对现场测试到的总孔隙水压力值减去静水压力后再进行潮位修正，即把任意时间任一潮位测得的超孔降水压力值修正到一个指定的同一潮位上，这样才能得到一个有规律性的观测曲线．本文提出了一种实用的修正方法，并在连云港庙岭围堰软基工程中应用，结果令人满意。     

动力荷载作用下软粘土的残余变形计算模式

在试验结果的基础上，提出了动力荷载作用下计算软粘土残余变形的模式。并将计算结果与不排水和部分排水情况下观测到的孔隙水压力及残余应变进行比较，两者具有较好的吻合性。本文所提出的计算模式可用来估算动力荷载（例如地震荷载、交通荷载）作用下建于软粘土地基上的建筑物及其它设施所产生的附加沉降。     

An Analysis of Groundwater in Sinjar Plain (Northwest of Iraq) Using WQI Model

INTRODUCTlONGroundwater is very important in arid and semi--arid areasand in areas located far away from sources of surface water. Itdoes not contain suspended materials, organic materials andbacteria (as long as it does not get polluted from othersources), but it mostIy contains mineraI and chemicaI com-pounds with identified quantities, depending on the type ofrocks presented in the area.The importance of groundwater relies on its quantity,avai1ability and how to substitute its used amo…     

A Methodology for Reliability-Based Design of Rock Slopes

Summary A reliability-based methodology for the design of rock slopes, that can easily be implemented by the practicing engineers is proposed. The advanced first-order second-moment (AFOSM) method is adopted as the reliability assessment model and its application is illustrated for the case of plane failure. A model is developed within the framework of first-order second-moment approach to analyze the uncertainties underlying the in situ shear strength properties of rock discontinuities. Here, particular emphasis is given on the assessment of uncertainties related to the shear characteristics of clean, unfilled rock discontinuities under low normal stress levels. An extensive literature survey on the shear characteristics of discontinuities is carried out in order to collect data for the quantification of uncertainties. The data extracted from this literature survey are classified and reprocessed so that they can be utilized in the uncertainty analysis model. A user friendly software called ROCKREL is developed to carry out the numerical computations and to make the proposed design format more practical. Received April 16, 2001; accepted June 10, 2002; Published online November 19, 2002 Authors' address: Prof. Celal Karpuz, Middle East Technical University, Faculty of Engineering, Department of Mining Engineering, 06531 Ankara, Turkey; e-mail: karpuz @metu.edu.tr     

Evaluation of rock mechanical behaviors under uniaxial compression with reference to assessed weathering grades

Summary  A weathering classification for granitic rock materials from southeastern Brazil was framed based on core characteristics. The classification was substantiated by a detailed petrographic study. Indirect assessment of weathering grades by density, ultrasonic and Schmidt hammer index tests was performed. Rebound values due to Schmidt hammer multiple impacts at one representative point were more efficient in predicting weathering grades than averaged single impact rebound values, P-wave velocities and densities. Uniaxial compression tests revealed that a large range of uniaxial compressive strength (214–153 MPa) exists in Grade I category where weathering does not seem to have played any role. It was concluded that variability in occurrences of quartz intragranular cracks and in biotite percentage, distribution and orientation might have played a key role in accelerating or decelerating the failure processes of the Grade I specimens. Deterioration of uniaxial compressive strength and elastic modulus and increase in Poisson’s ratio with increasing weathering intensity could be attributed to alteration of minerals, disruption of rock skeleton and microcrack augmentation. A crude relation between failure modes and weathering grades also emerged. Correspondence: Prof. T. B. Celestino, Universidade de S?o Paulo, S?o Carlos, Brazil     

风干含水量W65用作膨胀土判别分类指标的可行性研究

本文针对膨胀土的判别分类指标存在的一些问题,提出一种新指标--风干含水量W65.文中详细研究了它的测试方法,它与膨胀土的物理化学活性,物性指标及自由膨胀率ef等的关系。结果表明,W65能很好反映膨胀土的矿物组成或物理化学活性特征,而ef或WL则更能反映土的粒度组成或分散性特征。最后,在继承ef的判别分类成果基础上,考虑到塑性图的优点,建议采用W65-WL判别分类图。该图能区分膨胀土与典型红粘土,较单一指标判分膨胀土更合理适用。     

强夯法加固不同饱和土地基的比较试验研究

通过室内试验就中海石油炼化山东公司东营港（堆场区）场地的土性条件和加固前、加固后的变形和强度特征的变化进行了比较。此外,根据3个场地的现场实测资料的比较,分析了不同地层条件下强夯荷载作用引起的孔隙水压力的分布特征,最后研究强夯法加固饱和土地基的土性适用条件。     

面向数据共享的地球系统科学数据分类探讨

地球系统科学数据共享在国际、国内都有迫切的需求。由于地球系统科学固有的学科交叉性和综合性,如何建立科学、通用的数据分类体系是困扰该领域数据共享和服务的难题。首先综合分析了国际上地球系统科学领域主要的数据分类体系,重点对美国全球变化主目录(GCMD)分类系统及其2005—2013年的演变趋势进行分析,指出当前该数据分类呈现扁平化、两极化的显著特征。在此基础上,重点梳理了国家科技基础条件平台———地球系统科学数据共享平台的用户服务记录,揭示了用户访问频次最高的数据集和检索关键词。结合GCMD系统化、结构化的分类思想和国家地球系统科学数据共享平台用户化的数据服务需求,提出扁平化的地球系统科学数据目录分类和规范化的关键词表体系2种分类模式。     

Some Attempts for Estimating Rock Strength and Rock Mass Classification from Cutting Force and Investigation of Optimum Operation of Tunnel Boring Machines

Summary. Tunnel face and wall collapse are common during excavations performed by tunnel boring machines (TBMs) due to the difficulty of correctly identifying the properties of the excavated rock. This identification, however, can be simplified by using the cutting force to estimate rock strength, a method that has already proved quite successful in Japanese tunnel excavations. This paper summarizes knowledge relating to the cutting force obtained through tunnel excavation experience, and the relationship between rock strength and TBM operation is discussed. Although TBM operators rely on intuition to set the cutter head speed appropriately, this decision process represents a logical method of operation that takes advantage of the variable speed capability of the cutter head. Selection of appropriate support methods for the excavated face is also a critical issue in tunnel excavation. This selection process is based on the condition of the rock, which is difficult to determine quickly and accurately during tunnel excavation. The present paper uses the excavation of two tunnels to demonstrate that it is possible to assign rock mass classifications accurately based on rock strength when boring a uniform rock type. It is also shown that the rock mass can be classified from the rock strength normalized by the uniaxial compressive strength when boring through mixed rock types.     

水源地水质评价指数系统的研究

水源地水质评价指数系统吸取了国外及我国水质评价方法众家之长,在国家地表水环境质量标准的基础上,研制了一套水质分类、分级的综合指数系统.评价指数系统包括评价依据、综合指数的计算以及评价结果的水质含义和报告方法等.该指数系统计算简单,既易于公众理解,又有评价上的合理性     

内陆河高寒山区流域分布式水热耦合模型（Ⅰ）：模型原理

在全球变暖的背景下，我国多数大江大河源区存在冰川退缩、雪线上升以及多年冻土和季节冻土明显退化等现象，并由此造成河源区产流量减少以及生态环境恶化等诸多问题，这在内陆河山区流域体现的较为明显，但目前分布式水文模型中很少涉及冻土水热耦合问题。文章以黑河干流山区流域为例，构建了一个内陆河高寒山区流域分布式水热耦合模型（DWHC）。模型基于土壤水热连续性方程将流域产流、入渗和蒸散发过程融合起来，在植被截留、入渗、产流和蒸散发计算方面也有所改进和创新，部分模块具有多个可选择方案。模型设计了与中尺度大气模式MM5的嵌套接口，也可以用地面气象资料驱动。模型在1 km×1 km网格基础上，以日为时间步长，将流域土壤分为18类，土壤剖面分为3～5层不等，流域植被概化为9类。模型只需要土壤初始含水量、初始地温和常规气象资料，以及土壤和植被物理参数，就能够连续演算各层土壤的温度、液态含水量、固态含水量、感热传导、潜热变化、水势梯度、导水率以及水分入渗和毛细上升量等水文循环要素。主要介绍了模型的基本原理和构建思路，有关模型的地面资料驱动结果和与MM5嵌套结果部分，参见后续文章(Ⅱ)、(Ⅲ)。     

Two‐Stage Sulfide Mineral Assemblages in the Mineralized Ultramafic Rocks of the Laowangzhai Gold Deposit (Yunnan,SW China): Implications for Metallogenic Evolution

The Laowangzhai gold deposit, located in the Ailaoshan gold belt (SW China), is hosted in various types of rocks, including in quartz porphyry, carbonaceous slate, meta‐sandstone, lamprophyre, and altered ultramafic rocks. In contrast to other wall rocks, the orebodies in altered ultramafic rocks are characterized by the occurrence of a large amount of Ni‐bearing minerals. The ore‐forming process of the orebodies hosted by altered ultramafic rocks can be divided into two stages: pyrite‐vaesite‐native gold and gersdorffite‐violarite stages. The contents of As and Sb increased during the evolution of ore‐forming fluid based on the mineral assemblages. Thermodynamic modeling of the Ni‐Cu‐As‐Fe‐S system using the SUPCRT92 software package with the updated database of slop16.dat indicates the fS₂ in ore‐forming fluid decreases significantly from stage I to stage II. The decreases of fS₂ due to crystallization of sulfides and fO₂ due to fluid–rock reaction were responsible for ore formation in altered ultramafic rocks of the Laowangzhai gold deposit. Geological evidence, the in situ sulfur isotope values of pyrite, and the other published isotopic data suggest that the ore‐forming fluid for ultramafic rock ores was dominantly composed of evolved magmatic fluid with the important input of sediments.     

Geostatistical Evaluation of the Mechanical Properties of Rock Mass for TBM Tunnelling by Seismic Reflection Method

Summary. The evaluation of the rock mass mechanical properties by the seismic reflection method and TBM driving is proposed for TBM tunnelling. The relationship between the reflection number derived from the three-dimensional seismic reflection method and the rock strength index (RSI) derived from TBM driving data is examined, and the methodology of conversion from the reflection number to the RSI is proposed. Furthermore a geostatistical prediction methodology to provide a three-dimensional geotechnical profile ahead of the tunnel face is proposed. The performance of this prediction method is verified by actual field data.