Geohazards at Surface Coal Mines Caused by Mining Activities

This chapter presents a methodology of geohazard analyses caused by mining activities at coal mine “Suvodol” near the town Bitola in the Republic of Macedonia. The problems discussed here are connected with landslide with enormous dimensions. The process of sliding happened in several phases, with initial signs of sliding in 1993. The moment of global instability happened on October 27, 1995. Until now, several phases of reactivation are known. Its volume is about 30,000,000 m3. As a result of mass movements, about 8,000,000 tons of coal is concentrated (blocked) at the toe of the landslide. Upper of the main scarp, spaced about 250 m, the earth‐fill dam with a length of about 1000 m exists. The groundwater artesian effects are also present. At the toe of the landslide, the coal is partially involved in a process of self‐burning, and it produces environmental unfriendly gases. All these aspects show a very specific combination of natural and man‐made hazards that control the stability of the excavation and environment. The specific approach used to define risk scenarios for is then shown briefly. The suggested methodology can serve as an example for possible use in some other problems in coal mines

Gubici uslijed povijesnih potresa na području Balkana: Pregled javno dostupnih podataka

This study analyzes catastrophic losses due to earthquakes in the Balkan region. Analysis is based on the following data on earthquakes, collected from the OFDA/CRED International Disaster Database (Université Catholique de Louvain, Brussels, Belgium) for 1900 to 2010: numbers of fatalities, size of the affected population and costs of material damages. Catastrophic losses were caused by 62 earthquakes in countries within the region: Slovenia, Croatia, Bosnia and Herzegovina, Montenegro, Albania, Serbia, Romania, Bulgaria, Macedonia and Greece. The analysis shows that a significant number of people in the Balkan region were killed (4974) or were affected (2033723) by the earthquakes and that many countries suffered significant material damages (10410.16 million USD) during the analyzed period. The main disadvantage of using publicly available sources is the lack of consistent data on earthquake damages. A brief review of the most catastrophic earthquakes recorded in databases through the last 110 years is given, based on the data from publicly available databases.U radu se analiziraju gubitci uslijed katastrofalnih potresa u Balkanskoj regiji na temelju podataka o broju stradalih i materijalnoj šteti, a koji su prikupljeni iz OFDA/CRED Međunarodne baze podataka o katastrofama (Université Catholique de Louvain, Brussels, Belgium) za razdoblje od 1900. do 2010. Katastrofalne gubitke prouzročilo je 62 potresa u sljedećim državama u regiji: Sloveniji, Hrvatskoj, Bosni i Hercegovini, Crnoj Gori, Albaniji, Srbiji, Rumunjskoj, Bugarskoj, Makedoniji i Grčkoj. Analiza je pokazala da je u cijeloj regiji tijekom razmatranog razdoblja smrtno stradalo 4974 ljudi, 2033723 ljudi je zahvaćeno posljedicama potresa, dok je ukupna materijalna šteta iznosila 10410,16 milijuna USD. Kao glavni nedostatak javno dostupnih izvora podataka o potresima ističe se nekonzistentnost podataka o štetama nastalim uslijed potresa. U radu se također daje sažeti prikaz zapisa o najkatastrofalnijim potresima koji su se dogodili u posljednjih 110 godina, a na osnovi podataka iz drugih javno dostupnih baza podataka

THE TECHNIQUE FOR EXTRAPOLATION OF ROCK MASS INITIAL PARAMETERS DURING THE CONSTRUCTION OF THE TUNNEL

It is important to perform research to the degree that it is adequate to identify the features of the terrain composition, before, during, and after the building of facilities since predicting the behaviour of rock mass during tunnel construction is a complicated engineering challenge. Engineering research works in laboratories and in the field are of different scope and methodology during testing. In this paper, the established interdependencies of some of the basic parameters obtained during the testing of rock mass are presented: Edyn = f(Vp), Edyn = f(RMR) i Edyn = f(Q). Also, the relations between the engineering systems of rock mass classification and seismic primary waves are derived. RMR = f(Vp), Q = f(Vp). The relations were based on the examination of the rock mass for the construction needs of the tunnel on the Nis-Merdare highway. The results obtained in this study can be applied in environments that have similar lithological and structural characteristics

Analyses of Environmental Impacts of Non Hazardous Regional Landfills in Macedonia

This paper presents an assessment of potential environmental impacts for eight planned non-hazardous regional landfills in Macedonia. Waste quantities for each waste management region and landfill capacities are estimated. Expected leachate quantities are calculated using Water Balance Method. Analyses and comparison of the likely landfill leachate per capita are presented, demonstrating that higher rates of leachate are generated per capita in waste management regions with higher annual sums of rainfall. An assessment of the potential landfill impacts on the water environment taking into consideration local geology and hydrogeology conditions is presented. Some general measures for leachate treatment that are in compliance with the modern EU standards are indicated. The goal of the study is to facilitate a better understanding about the sustainable waste management practices in cases of landfilling of municipal solid waste

Model for GIS landslide database establishment and operation in Republic of Macedonia

Landslides are one of the most damaging and most significant geo-hazards in the Republic ofMacedonia. Due to many reasons landslide data collection in the past have been generally unsystematic. Knowingthat new occurrences are to be expected in future, brief overview on landslide databases in Europe is given and modelfor establishing and operation of national GIS landslide database is proposed in the paper. Model for assignment ofgovernmental body on landslides, along with structure and way of operation of the envisaged database is presented.Formation of this landslide database is the basic step towards better understanding of the landslide hazard in future.This database will enable conditions for selection of most endangered regions and selection of appropriate models forlandslide hazard and risk zonation. As a result, land use planning will become more efficient, and vulnerability ofpeople and goods will be decreased. In this context, some results from recent landslide susceptibility assessment studiesare also presented

ERMR System – an Useful Tool In Defining of Technology for Excavation

This article presents the basis of classification system named as excavation rock mass rating system (ERMR). The purpose for system development comes from the fact that in all civil engineering or minning projects, one of the key problems is to addopt technology of excavation on the characterisstics of natural environment, and to chosse and adequate equipement for excavation. Methodology for establishing of ERMR system is based on ranking and scoring of careffuly choosen classification parameters. The parameters for classification and the range of parameters in each class is explained briefly. The system is correlated with some known rating rock mass systems. The classification is developed on the bases of numerous investigations for different civil engineering and mining projects, as well as laboratory testings of rock mass parameters. The case histories used in developing of the ERMR system are noted. For each rock mass class, an adequate technology of excavation is suggested, and the excavation classes are corelated with unit price of excavation in different media.The practical aplication of ERMR system is undelined

ASSESMENT OF ROCKFALL DITCH EFFECTIVENES BY APPLICATION OF COMPUTER SIMULATIONS, AN PROBABILISTIC APPROACH

Different types of geohazards frequently affect road and railway traffic. Among them, in the case of mountainous terrains, the rockfalls are considered to be most usual. They cause economic losses of different magni-tude, in some cases even loss of human life. In order to improve the management of the rockfall hazard and risk, researchers had been developing many different methodologies for assesment and design of effective control, protection and preparedness measures. One of the approaches is to apply a structural measure along the road/railway line in the form of a rockfall catch ditch at the toe of the rock cuts. Experimental field tests and computer simulations by many authors have investigated the effectiveness of these ditches, with main goal being to design ditches that are as effective as possible. The paper presents application of computer simulation technique coupled with probabilistic analysis. The main idea is to test the effectiveness of rockfall catch ditches with different geometries, by simulating rockfall blocks of different geometrical shapes. Beside variation of the ditch and block geometry, also varied are the height and slope angle of the rock cut. Results from the probabilistic simulations show the different degree of ditch effectiveness in the investigated cases. The approach is considered useful for the goals in the design process, with main benefits being the improved management of the rockfall risk and economical rationalization of cuts design

Preparation of GIS landslide inventory for the Polog Region

This paper deals with preparation of Geographic Information Systems (GIS) landslide inventoryfor the Polog region. A number of activities were undertaken for this purpose, such as: analysis of own data on landslides, visits of the sites noted in the surveys filled by municipalities, digitizing of landslides from old geological mapsin scale 1:25000, analysis and digitizing of landslides from the archive of the Geological Survey of Macedonia, interviews with employees and retired colleagues from geotechnical companies, analysis of landslides along the channelsof the “Mavrovo” system, visit to the National University in Tetovo and joint site visit, and visits to several geotechnicalcompanies in Macedonia. Since this is the first attempt to create a regional landslide inventory in N. Macedonia, theadopted structure of the inventory is presented in the paper. Moreover, to see what benefits can be gained from theavailability of such inventory some of the most important findings regarding the landslides are presented further. Currently the inventory consists of 136 occurrences, and in time it should be appropriately updated. The main findingsrelated to the distribution and characteristics of the landslides show that future analyses should include preparation oflandslide susceptibility/hazard models both for shallow and deep landslides, as well as for flow-like type of slides. Inthe following stages of investigation, it is planned to analyze a LIDAR (LIght Detection and Ranging) survey that isbeing prepared for the region and incorporate more landslides in the inventory. Also, findings of the InSAR (Interferometric Synthetic Aperture Radar) analysis will be combined with the inventory, which will lead to conclusions on themovement rates of detected sites. The latter two approaches will be presented in future papers

Preliminary regional landslide susceptibility assessment using limited data

In this paper a heuristic approach for preliminary regional landslide susceptibility assessment using limited amount of data is presented. It is called arbitrary polynomial method and takes into account 5 landslide conditioning parameters: lithology, slope inclination, average annual rainfall, land use and maximum expected seismic intensity. According to the method, in the first stage, a gradation is performed for each of the carefully selected conditioning parameters by assigning so called rating points to the grid cells on which the region is divided. Values of the rating points vary from 0 to 3 and depend on the parameter’s character and importance for landslide development within the region of interest. A so called Total Landslide Susceptibility Rating (TLSR) model is obtained by summing the individual rating points of each parameter and dividing the region into five susceptibility zones according to Jenks natural breaks classification. Verification of the TLSR model is then performed by overlaying the landslide inventory map of the selected region over the prepared susceptibility map. The sensitivity of the model can be additionally tested by multiplying the conditioning parameter’s rating points by sensitivity coefficients. In this way, additional landslide susceptibility models are obtained, named Weighted Total Landslide Susceptibility Rating (WTLSR) models. As a practical example of the method, two TLSR models are presented here for the Polog region in Republic of Macedonia, for return periods of maximum expected seismic intensity for 100 and 500 years. With over 74% of mapped landslides falling in zones of high and very high susceptibility, the results are considered satisfactory for regional scale landslide modelling and are comparable with more advanced quantitative methods. Additional WTLSR models were prepared, and their correlation identified the best model. The presented approach is considered to be very convenient for conducting preliminary regional landslide susceptibility assessments with the ability to fine-tune the results. Due to its simplicity, it can be applied to additional landslide conditioning parameters other than the one presented in the paper, depending on the region of interest and available data sources. It is especially practical for use in developing countries, where various organizational, technical and economic constraints prevent application of more advanced data driven methods. Limitations and restrictions of the approach are also discussed