The application of rock mass classification systems to underground excavation in weak limestone, Atatürk dam, Turkey

The Atatürk dam was built across the Firat River on clayey limestone. A grout curtain, providing impermeability in the left and right abutments, was done in grouting galleries. The well known rock mass classification systems for tunneling purposes [rock structure rating (RSR), rock mass rating (RMR) and rock mass quality index (Q)] were used to classify the rock mass along these galleries. Based on RSR, RMR and Q values, the rock masses in the galleries have been classified into three different classes. Correlation between the three classification systems is discussed and suggestions are made for using rockbolt, shotcrete with wiremesh and steel ribs for supporting the rock mass.     

Landslide zoning in a part of the Garhwal Himalayas

 The Himalayas are undergoing constant rupturing in the thrust belt zone in the Garhwal Himalayas, due to which earthquake and mass movement activity is triggered. These processes of mass movement and landslides have been constantly modifying the landscape. Landslides are one of the indicators of the geomorphological modifications taking place in this active and fragile terrain. This work is aimed at providing another example of landslide susceptibility mapping based on geological and geomorphological attributes. The data collected from aerial photographs, topographic sheets and the image suggests that there is a correlation between the distribution of landslides and some of the geological and geomorphological factors, for example, the distance from an active fault, relative relief and slope. Parameters like factor of safety, altitude, relief, slope and the distance from the fault lineament have been included in the study. A rating system has been applied to the factors for arriving at a quantitative estimate of landslide susceptibility for each physiographic unit. Since terrain classification forms the foundation of this work, the entire study can be grouped into two sequential activities: (1) the terrain classification and (2) landslide susceptibility mapping. The result is the landslide susceptibility zoning map presented. The landslides have not been classified with respect to time and may represent the final result of the on-going geological, geomorphological and seismic activity since the Holocene period or late Pleistocene time when the glaciers retreated. The area chosen for the study lies between Badri gad and Barni gad in Yamuna valley region of the Garhwal Himalaya where a very large scale investment is in the pipe line for Hydroelectric power generation. Received: 12 August 1993 · Accepted: 13 January 1998     

江西中部新元古代潭头群的建立

江西中部在元古代神山群黑色千枚岩之上,早震旦世古家组砾岩或含砾千枚岩之下,有一套以火山碎屑岩夹酸性火山熔岩为主的地层。这套地层命名为潭头群,自下而上划分为田东组、火峡岭组、上施组,总厚达２０００ｍ。上部２个组产丰富的微古植物化石,时代大部分属于蓟县纪—震旦纪;下部田东组的熔岩测得锆石ＵＰｂ年龄为（１０２７±３６）Ｍａ。根据上述情况,确认潭头群属于新元古代,时限为１０５０～７４０Ｍａ之间。     

塔中地良奥陶系地层格架与沉积演化

塔里木中部地区奥陶系大致以Ⅰ号断裂为界分东北和西南两个地层分区,自下而上分白云岩段、灰岩段、泥质灰岩段、泥岩夹灰岩段、泥岩夹砂岩段、砂砾岩段、泥岩夹砂岩段、泥岩灰岩互层段和砂岩段等9个岩性段。早奥陶世,塔中地区以碳酸盐岩台地相为主,自西向东为局限台地相、开阔台地相、台地边缘相和深水斜坡相。中——晚奥陶世,塔中地区西部以混积陆架相为主,东部以深水斜坡相为主。中—晚奥陶世,塔中东部及塔东地区在构造上具弧后前陆盆地性质。中—上奥陶统地层完整地记录了该盆地从形成发展到消亡的过程,即早期为深水斜坡相复理石活动沉积,晚期演化为浅海陆架相稳定沉积。     

An automated approach to the classification of the slope units using digital data

Digital elevation and remote sensing data sets contain different, yet complementary, information related to geomorphological features. Digital elevation models (DEMs) represent the topography, or land form, whereas remote sensing data record the reflectance/emittance, or spectral, characteristics of surfaces. Computer analysis of integrated digital data sets can be exploited for geomorphological classification using automated methods developed in the remote sensing community. In the present study, geomorphological classification in a moderate- to high-relief area dominated by slope processes in southwest Yukon Territory, Canada, is performed with a combined set of geomorphometric and spectral variables in a linear discriminant analysis. An automated method was developed to find the boundaries of geomorphological objects and to extract the objects as groups of aggregated pixels. The geomorphological objects selected are slope units, with the boundaries being breaks of slope on two-dimensional downslope profiles. Each slope unit is described by variables summarizing the shape, topographic, and spectral characteristics of the aggregated group of pixels. Overall discrimination accuracy of 90% is achieved for the aggregated slope units in ten classes.     

为生态建设服务的吉林省西部景观类型研究*

在GIS技术支持下,依据有关原则,对吉林省西部景观类型进行了划分;选取地形和地貌、人类对景观的利用水平以及沙碱化程度三个指标对景观类型进行了稳定性评价。在此基础上,结合景观生态学的有关理论,采用类型重要值、嵌块体密度和平均内缘比率分析了吉林省西部各小区(东部区,中部区和西部区)内不同稳定类型的景观空间结构,提出了重建不稳定类型应以西部区为重点并要注意其内部结构的协调性、防止亚稳定类型向不稳定类型过渡也应以西部为重点、东部区的景观生态建设应注意增加其异质性等建议。     

Using logistic regression to merge mineral resource databases

The purpose of this project was to develop and test a methodology for determining the likelihood that mineral resource location records from two nationwide mineral resource information databases represent the same site. The long-term goal is to create a comprehensive database by merging the Mineral Resource Data System (MRDS) of the U.S. Geological Survey, and the Mineral Availability System/Mineral Industry Location System (MAS/MILS) of the U.S. Bureau of Mines (now part of the Geological Survey). Part of that process involves linking records for the same site from each database. Match probabilities were estimated using a logistic regression of mineral resource location attributes, derived from known matched (cross-referenced) and known unmatched randomly sampled mineral site pairs from within the conterminous United States (n=10,000). Model accuracy was assessed using a randomly sampled test dataset, not used in logistic model development (n=4,000). Probability distributions were similar between the development and test datasets. The overall agreement beyond chance was good for the test data set using the kappa statistic. Classification accuracy was 89.6% for known matched site pairs and 84.0% for known unmatched site pairs based on a probability threshold of 0.50 for a match. Distributions of attributes were similar between the development and test datasets. This classification method is a viable approach for estimating match probabilities between database records.     

铜陵地区深埋型岩溶形成机制及分布特征

铜陵地区现代岩溶发育深度一般在２００ｍ以内，但在特殊地质块段存着埋藏深度更大的岩溶，它的存在对地下水资源的开采和深埋矿床的开采具有重要意义，该类岩溶按成因可分为岩浆侵入型，断裂构造型和古岩溶，本文就其形成机制和分布特征进行了探讨。     

试论断层分类

对传统的根据断层两盘相对运动方向的形态分类提出补充意见,它们应该包括:(1)正断层;(2)逆断层;(3)平移断层;(4)水平断层;(5)垂直断层;(6)开口断层。同时提出原生断层与借生断层,真正断层与视正断层等新概念及其分类。     

白水峪水电站右岸坝下游边坡岩体的RMR-SMR分类及稳定性评价

本文简要介绍了边坡岩体分类的RMR-SMR系统。结合白水峪边坡, 通过自然历史分析和稳定性计算, 讨论了运用SMR系统进行边坡岩体分类的改进意见。