TMMOBABSRACT: The strength of a rock material- is determined in the laboratory on representative standard samples. In the case of a closely jointed rock mass it is not possible to obtain a sample with suitable dimensions to represent the whole rock mass. Since 1980, the empirical Hoek-Brown failure criterion (Hoek and Brown, 1980} began to be used to overcome the difficulties in laboratory shear strength determination of jointed rock masses,. The empirical failure criterion was used in conjunction with the Geomechanics Classification System-RMR (Bieniawski, 1989) until 1994. However, due to the limitations in the RMR classification scheme particularly for very poor quality rock masses and for unrealistic rating adjustments for discontinuity orientation in slopes, the feature criterion has been modified over the years.. Recently,, the originators of the criterion introduced a new index., called Geological Strength index (GSI), in to the criterion. The GSI is based upon the visual impression on the rock mass structure and consists of twenty codes to identify each rock mass category and to estimate the GSI value (Hoek and Brown, 1997). Because rock mass classification requires time consuming procedures and has some limitations, the existing GSI system seems a more practical parameter for the determination of the strength of jointed rock masses from field observations. However,, the system is lack of measurable and more representative parameters, and related interval limits or ratings for describing the structure and surface conditions of discontinuities. This situation results in subjective assessments on the determination of the GSI value: In other words,, it is possible to estimate different GSI values for the same rock mass by different persons. The other importani problem of the criterion is the use of undisturbed and disturbed rock mass categories for determining the parameters in the criterion, for which clear guide Une s are lacking.. It is also noted that the data supporting of the revisions have not been published. These uncertainties make it difficult to judge their validity and performance.. In order to provide a more quantitative basis for evaluating GSI values, the authors of this paper suggested some modifications by introducing easily measurable rock mass parameters with ratings and/or intervals. For the purpose, two terms, namely Structure Rating (SR) based on volumetric joint count and- Surface Condition Rating (SCR) from, the input parameters are introduced in to the GSI system, and the modified GSI chart is established. In the latest version of the failure criterion (Hoek and Brown, 1997; Hoek et al., 1998) average undisturbed in-situ conditions are considered to estimate the GSI without application of any adjustment due to any disturbance effect, such as Masting.. Method of excavation,,, major planes of weakness or change in stress are considered, as local features influencing the rock mass at a particular .location. Therefore,, the influence of such factors should be compensated, and necessary adjustments should be taken in to consideration. In this study, a method was proposed to assess the influence of disturbance on rock constants due to method of excavation as discussed in detail by Sönmez, and Ulusay (1999`),, The modifications and the method suggested have been applied to well studied five slope instabilities from Turkey to check the validity and performance of the modifications and the methodology of parameter estimation, Four cases were selected from the slopes excavated in heavily jointed rock masses and one from spoil piles in a strip coal mine. The application of the suggested modifications and the method examined by the hack analysis of the failures indicated that the use of GSI value determined from the suggested modified chart and consideration of disturbance effect confirmed the limit equilibrium condition for the investigated failed slopes. The back analysis results from a spoil pile instability revealed that spoil pile materials consisting ofblocky and angular rock pieces with small amount of fines could be categorized as a disintegrated rock mass in the GSI system and the criterion seemed to be applied to spoil materials,. However, future applications of the suggested modifications on to failure case studies both from surface and underground excavations may provide a better tool for more precise guidelines and to check the performance of the equations of the criterion.
ABSTRACT: In recent, years,, the Suf area, has `become highly populated, increasing- the demands on water resources for various uses.. This, study aims, to evaluate the water quality of major` springs In the. Suf area.. In this respect. 11 mainsprings emerging from two different aquifers (Hummer aquifer` A4,, and Nau`r limestone aquifer Al) werechemically analyzed... Chemical analyses performed include -TDS,, Ca3+, Mg2+, Na+ K+, CT, HCO3 ; SO42" .and NO3as, well as pH, EC and. temperature. Results, show that these springs, have different chemical compositions, which,reflect., to a. large extent, the geological character of the two aquifers. In. addition.,, historical data on. spring chemistry were also used to show the variations and. long term trends in water quality., Generally,» the waters of majorsprings in the area, are of HC0` 3 and. Ca2+ type... Chloride ,and sodium ions make the main contribution to- the salinity of spring waters,, while $Q2 4 and Mg21" concentrations are moderate. Over all, chemical content of groundwater from various, springs is dominated by NO3, HCO`3, Cl",, Na+, and, Ca2+`.. Suf, Fawwer,, Um-Faraj, Al-garaj andNabhan springs show, to some extent, degradation in. the water quality.
ABSTRACT: The evaluation of potential rock slope failures using stereographic projection techniques known as kinematic analysis is one of the most important parts of a slope stability investigation to be carried out in in jointed rock media.., In conventional stereoprojection techniques for the assessment of possible rock slope failures,, the peak orientations of joints together with the slope geometry and the friction angle of the weakness planes are used,, Other possiMe joint orientations which may be encountered in the rock media are ignored.. In the presemi study, possible wedge failures which can develop in jointed andésites cropped out .Ankara, and its vicinity were investigated using both conventional and probabilistic kinematic analysis methods, and risk maps were produced using the results obtained from kinematic analysis and. a. comparison was made between the results: According to the results obtained front this study, probabilistic risk map are more realistic than the map using conventional kinematic analysis,, because, all the actual wedge type slope failures developed in the study area are located on the risk zones of the probabilistic risk map. When three peak orientations of the discontinuities are used for the preparation of the risk map, 20% of the study shows wedge type failure risk. However, `this value goes up to 73% when the probabilistic kinematic analysis: is applied, in conclusion, each possible discontinuity orientation must be taken in to consideration in a kinematic analysis research program.. This phenomenon is important for the selection and planning of settlement regions particularly, because,, a failure can cause important hazards ami loss of life.. Besides, the procedure described in the present study is very simple.
ABSTRACT: Ore deposit evaluation techniques by geostatistical simulation were first introduced some 25 years ago,, it has not fulfilled its promise as a major toot in the eartksciences. This has been largely due to two main reasons; there are some shortcomings in the method which, although recognized early on by some practitioners,, have been stow to be acknowledged and rectified, and alternatively wide usage qfkriging methods (there is although a big difference between kriging and simulation). Â survey of geostatistical simulation methods is given in Dowd (1992). Amongst proposed methods is Davis" (1987a) LU (lower and upper) decomposition method and related matrix- polynomial approximation method (Davis,, 1987b). The LU-matrix (lower and. upper) decomposition method of conditional simulation allows fast generation of stochastic processes on smallmoderate sized, grids. The method is simple and based on the LU triangular decomposition of the matrix of covariances between data, locations and simulation grid, locations (Davis, 1987a; Alabert,, 1987).. Covariances matrices are symmetric and positive-definite and therefore can be decomposed in to the product of a lower and an upper triangular matrix,. The advantages of the LU method are that it is simple to implement, performs conditioning simultaneously with simulation, is not limited to particular forms of covariance functions and handles anisotropies,. The main drawback of this method is the amount of storage required which, at least in its general form as presented,, effectively limits its application to less than 1000 grid locations. When there are many data, or when there is a large number of points on which values are to be simulated, the correspondingiy large matrices cannot he handled by classical decomposition algorithms
ABSTRACT: In this study, deformations occurred on the buildings located doing the sloping surface of Kızıltepe located 6km Northwest of Konya, of Plia-Quaternary age silty and clayey sand were investigated., Inclinations of the slopes range between 5°h and 15°}?. The foundations ofttiplex houses and six stories apartments were build partlyon the natural soil and partly on the fiil ground. Six months after the construction, fence wails had been collapstd and some apartments had been leaned and dangerous cracking occurred. Using Modified Bishop and Modified Janbu methods, stability analysis of Kızıltepe slopes have been made on the 20 selected profiles, involvingdeformed buildings and naturel soils and fill ground. Calculated safety factors have shown that there are not in stability problems on the natural slopes. On the improved and- loaded slope profiles, safety factors generally exceed 1,5, excepting two of profiles where safety factors are found as 1,3 and 1,4. No indications of landslips havebeen observed. According to the result of consolidation tests in the 50 kN/m2 pressure stage,, coefficient of compressibility of filled soil to the natural soil ratio is approximately 3,9. This ratio shows that fiil ground undergoesmore settlement than natural soil. Differential settlements up to 13 cm have been determined The cause of deformations in the structures are thought to be due to differential settlements
ABSTRACT: The point load index, test is .based on the principle that rock sample is broken between two conical platens..Faiiure load and specimen dimensions are used to calculaie the point load strength index and this index is usedin engineering geological studies.. In this paper, the problems related to the point load testing device and the common mistakes of the users are discussed. Based- on the experience of the author, a proposal far including "B* "dimension of the rock, failure time, and. textuml and structural information of the failure stiff ace of rock in thepoint load test form is given, k-value, defining the ratio between the uniaxial compressive strength (s&J and thepoint load strength index (Js(50))f varies significantly for different rocks. Therefore, k-values for different rocksshould be assessed for engineering projects. In this study, a linear relationship with high correlation coefficientbetween (oc) and (ls^{rj) is given for tuffs,
ABSTRACT: Sıcak Çermik, Sankaya and Uyuz Çermik travertine deposits around Sivas are among the most importanttravertine deposits in Turkey. Travertine deposits consist of nearly pure caleite, and. show stratifonn and veintype depositional styles, Banded and spongy structure and micritic texturtfis dominated within the stratifonn typetravertines, while albatr structure and sparitic texture is dominant within the vein type travertine occurences .In this study; industrial characteristics such as; block size, color and ornament sliding, polishing., mohs-hardness, slake durability index, schmidt hardness, transparancy, unit volume mass; specific mass, compactness ratio,water suction relative to mass and volume, porosity, abrasion, uniaxial compressive strength, uniaxial compress ive strength lifter the frost, bending strength, blowing strength,, durability lo the frost, frost lost durability toatmospheric influences, resistance to rusting and acids were investigated and evaluated.The results of these investigations and évaluations show that all these characteristics ofihe travertines inthese deposits range in the Iimites what should be in travertines and they are well qualified materials, suitable touse as facing stone
ABSTRACT: X-Ray diffraction, pétrographie microscopy and SEM analysis are used together to obtain qualitative aod quantitative information on the microstucture of kaoilinite-illite-quartz bodies,.. The pétrographie- microscope is used to analyse of the microstructure and mineralogy of the fired products. Bur the results have not been entirely satisfactory because of the inability to detect crystalline particles, of submicrometer mulHte, cristobalite and pores, The. body consists of mullite cristobalite and quartz (crystalline phases) in a composite structure where crystals and porosity are embedded in the matrix of amorphous/glassy phase.. Both glass and amorphous phases .appear in more or less significant amounts in all the studied fired clay bodies., The presence of quartz, detrital mica, and Ca- Na feldspar indicate bodies-being usually fired under nonequlibrium conditions and that many chemical reactions do not go to completion because of the lack of sufficient, heat treatment and of intimate contact of the constituents. If the reactions were allowed to go to completion this would result in a large glassy phase that would endanger the desirable properties of the clay based ceramic bodies.
ABSTRACT: The techniques used in the gold mining are not different front the ones used in the other metallic ores, Following the liberalisation, the ore excavated from the mine is subjected to the extraction process for the gold. According to the mineralogy of the ore., cyanidation, floatation or gravita ton is applied- at this stage.. Cyanklation has a share of 83 % in the world g(dd production at present. Developed countries provide 70 % of the world gold production. Cyanide (CN), is a simple compound of carbon and nitrogen continuously met through the daily life.. Cyanide produced by the different plants is present in the natural environment as well. Cyanide, not resembling to the ottter chemicals dangerous for the environment,, is know!} as a material not accumulating in the living organisms and non-carcinogenic or -mutagenic. It is na tit ratty degraded and decomposes to its elements by sunlight, bacteria and plants. Varions cyanide complexes are used in the metal processing and e tec!Toplat ing,, mining, plastics, paint, electronics, agricultural chemicals and medicines.. Sodium cvankle used in. the mining sector is less than 20 % of the total demand for cyanide. The cyanide import t »f Turkey is 2500 Urns in the previous year to use in the industry.. Sodium cyanide has been used safely and effective!)` in the gold mining fin- 100 years., Bui it is a dangerous chemical that must always be used with caution. The adverse effect of cyanide to the environment is successfidly prevented by the measures taken during and after the mining activities. Cyanide concentration of the solution is towered by the chemical destruction method to i ppnı i I tng/t) level fitting with the standards for the waste deposition. Then, this material spreading at the tailings pond is destntcted completely by the effect of sunlight Tailings pond is reinforced from the bottom and the flanks with clay and geomemhrane in order to prevent the leakage in to the environment. Practically, it is accepted that lining these two materials in succession provides the "zero permeability*`. It is ktwwn from the researches that the process water discharged to the tailings pond is completely destriicted between 5 and 12 mouths according to the cyanide concentration, it is clearly indicated, in the various publications that due to the cyanide use in the gold mining there has been any accident resulted in death till today..
ABSTRACT: Although karst features of Turkey are rich,, the studies regarding karstology and speleology have not beganlong ago. By the beginning of 1940`s following the pioneering works of some Turkish, German and French scholars, researchers often found, themselves in difficulty when writing on these sciences as they had. to find an equivalent for each specific word. Researchers like Alagöz (1944),,, Aygen (1959) aod Izbirak (1976) have long agopointed out. the need for such studies in their works. They used some translation words for some new terms aswell as the- words used by local people,. The first and. most detailed study of a karst terminology with Turkish equivalents was published by FAD in, 1972 including 194 entries,. Although, no consistent terminology or glossarystudy has been made about Turkish karst since then, we know that a more detailed study will be on the way byother reearchers, soon.. If we consider the technical terms used by Turkish, scientists in general, we will notice that,they are: generally taken from French, English, and Serbo-Croatian. Also some important French and Serbo-Croatian karst terms are included in this list of 300 words,, The presented work is an attempt to remedy this need though authors are conscious that this attempt fells short of the needs of engineering sciences.. As the colloborationof Turkish and. Hungarian speleologists in the past, few years invoked the need of such attempts,, we strongly hope and wish the: intensive communication of the researchers of these countries in the future., We also believe thatto abet the scientific communication between different language«, the local terminologies of each country must.not be "forgotten in these studies