[pt] Em uma mina a céu aberto, a estabilidade dos taludes rochosos é um dos maiores desafios na engenharia das rochas devido aos processos geodinâmicos que formaram o depósito de minério, fazendo de cada depósito complexo e único. Algumas das complexidades encontradas comumente são: a geologia nos arredores do depósito, a alta variabilidade das propriedades, os complexos defeitos estruturais, o grau de alteração das rochas, a informação geomecânica limitada, etc. Antes de avaliar a estabilidade de taludes devemos caracterizar o maciço rochoso. Para caracterizá-lo se têm construído os modelos geológico, estrutural e do maciço rochoso para formar o modelo geotécnico como recomenda o projeto Large Open Pit (LOP), um projeto de pesquisa internacional relacionado à estabilidade de taludes de rocha nas minas a céu aberto. Uma vez construídos os domínios geotécnicos, a estabilidade de taludes rochosos pode ser avaliada para cada domínio pelos métodos de equilíbrio limite ou numéricos como o método dos elementos finitos ou o método dos elementos discretos. O uso do método depende de diversos fatores, como a influência dos elementos estruturais, a importância da análise, a informação disponível, etc. Os métodos de equilíbrio limite como os tradicionais de Bishop e Janbu podem ser usados na avaliação de estabilidade de grandes taludes de rocha que são susceptíveis a falhas rotacionais do maciço rochoso. Já o método de elementos finitos se tem desenvolvido rapidamente e tem ganhado popularidade para a análise de estabilidade de taludes no caso em que o mecanismo de falha não esteja controlado por estruturas discretas geológicas. Os métodos de elementos finitos estão baseados em modelos constitutivos de tensão – deformação para rochas intactas e têm dificuldades em simular famílias com um número grande de descontinuidades dentro do maciço rochoso. O método dos elementos discretos permite simular um número grande de descontinuidades assim como também permite a simulação de grandes deformações. A presente dissertação usa o modelo SRM (Synthetic Rock Mass) para avaliar a estabilidade de taludes de uma mina a céu aberto no Peru. O SRM é uma nova técnica para simular o comportamento mecânico de maciços rochosos fraturados e permite simular a propagação de fraturas e os efeitos da anisotropia. Está técnica usa o modelo BPM (Bonded Particle Model) para representar a rocha intacta e o SJM (Smooth - Joint Contact Model) para representar as estruturas do maciço rochoso dentro do programa PFC. Para a modelagem estrutural se utilizou o método DFN (Discrete Fracture Network). Para a determinação dos modelos geológicos e estrutural se utilizou o programa Petrel e para a análise de estabilidade de taludes usando o modelo SRM se utilizou o programa PFC 4.0 na versão 2D. / [en] In an open pit mine, stability of rock slope is one of the most challenges in rock mechanics due to geodynamic processes that formed the ore deposit, making each deposit complex and unique. Some of the complexities commonly encountered are: the geology in the vicinity of the deposit, the high variability of properties, the complex structural defects, the rock alteration degree, limited geomechanical data, etc. Before evaluating the slope stability we should characterize the rock mass. To characterize it we have built the geological model, structural model and rock mass model to form the geotechnical model as it recommends the Large Open Pit project (LOP), an international research project related to stability of rock slope in open pit mines. Once constructed geotechnical domains, the stability of rock mass slope can be evaluated for each domain by using some known methods like limit equilibrium, the finite elements and discrete element methods. The use of the method depends of different factors like influence of structural elements (defects), importance of analysis, available information, etc. Limit equilibrium traditional methods like Bishop and Janbu can be used to evaluate the stability of large rock slopes that are susceptible to rotational failure of rock mass. Since the finite element method has developed rapidly and has gained popularity for the slope stability analysis in the case where failure mechanism is not controlled by discrete geological structure. Finite element method is based on constitutive models of stress-strain for intact rocks and has difficulties in simulating sets with a large number of discontinuities within the rock mass. The discrete element method allows to simulate a large number of discontinuities and also allows the simulation of large deformations. This dissertation uses the SRM (Synthetic Rock Mass) model to evaluate the stability of slopes in an open pit mine in Peru. The SRM model is a new technique that allows the simulation of the mechanical behavior of fractured rock mass taking into account propagation of fractures and anisotropic effects. This technique uses two well established techniques like BPM (Bonded Particle Model) for representation of intact rock and the SJM (Smooth-Joint Contact Model) to represent the structural fabric within the PFC program. For structural modeling it was used DFN method (Discrete-Fracture Network). To determine the geological and structural model it was used the Petrel program (Version 2010.1) and for slope stability analysis with the SRM model it was used the version 2D of the PFC 4.0 program.

Thesis (MSc)--Stellenbosch University, 2011. / ENGLISH ABSTRACT: FLAC3D is a three-dimensional explicit nite difference program for solving a variety of solid mechanics problems, both linear and non-linear. The development of the algorithm and its initial implementation were performed by Itasca Consulting Group Inc. The main idea of the algorithm is to discritise the domain of interest into a Lagrangian grid where each cell represents an element of the material. Each cell can then deform according to a prescribed stress/strain law together with the equations of motion. An in-depth study of the algorithm was performed and implemented in Java. During the implementation, it was observed that the type of boundary conditions typically used has a major in uence on the accuracy of the results, especially when boundaries are close to regions with large stress variations, such as in mining excavations. To improve the accuracy of the algorithm, a new type of boundary condition was developed where the FLAC3D domain is embedded in a linear elastic material, named the Boundary Node Shell (BNS). Using the BNS shows a signi cant improvement in results close to excavations. The FLAC algorithm is also quite amendable to paralellization and a multi-threaded version that makes use of multiple Central Processing Unit (CPU) cores was developed to optimize the speed of the algorithm. The nal outcome is new non-commercial Java source code (JFLAC) which includes the Boundary Node Shell (BNS) and shared memory parallelism over and above the basic FLAC3D algorithm. / AFRIKAANSE OPSOMMING: FLAC3D is 'n eksplisiete eindige verskil program wat 'n verskeidenheid liniêre en nieliniêre soliede meganika probleme kan oplos. Die oorspronklike algoritme en die implimentasies daarvan was deur Itasca Consulting Group Inc. toegepas. Die hoo dee van die algoritme is om 'n gebied te diskritiseer deur gebruik te maak van 'n Lagrangese rooster, waar elke sel van die rooster 'n element van die rooster materiaal beskryf. Elke sel kan dan vervorm volgens 'n sekere spannings/vervormings wet. 'n Indiepte ondersoek van die algoritme was uitgevoer en in Java geïmplimenteer. Tydens die implementering was dit waargeneem dat die grense van die rooster 'n groot invloed het op die akkuraatheid van die resultate. Dit het veral voorgekom in areas waar stress konsentrasies hoog is, gewoonlik naby areas waar myn uitgrawings gemaak is. Dit het die ontwikkelling van 'n nuwe tipe rand kondisie tot gevolg gehad, sodat die akkuraatheid van die resultate kon verbeter. Die nuwe rand kondisie, genaamd die Grens Node Omhulsel (GNO), aanvaar dat die gebied omring is deur 'n elastiese materiaal, wat veroorsaak dat die grense van die gebied 'n elastiese reaksie het op die stress binne die gebied. Die GNO het 'n aansienlike verbetering in die resultate getoon, veral in areas naby myn uitgrawings. Daar was ook waargeneem dat die FLAC algoritme parralleliseerbaar is en het gelei tot die implentering van 'n multi-SVE weergawe van die sagteware om die spoed van die algoritme te optimeer. Die nale uitkomste is 'n nuwe nie-kommersiële Java weergawe van die algoritme (JFLAC), wat die implimentering van die nuwe GNO randwaardekondisie insluit, asook toelaat vir die gebruik van multi- Sentrale Verwerkings Eenheid (SVE) as 'n verbetering op die basiese FLAC3D algoritme.

A implantação segura e a viabilidade de um projeto de barragem dependem de se conhecer, com o máximo de clareza, as características geotécnicas do substrato rochoso do local de implantação. Para tanto, são realizadas campanhas de investigação geotécnica para a elaboração de modelos geológicos e geomecânicos, os quais podem apresentar erros devido à variabilidade natural, amostragem insuficiente, interpretação bidimensional e subjetividade das interpretações. Visando diminuir a subjetividade das interpretações acerca das características geomecânicas, a mecânica das rochas utiliza classificações de maciço rochoso, tais como sistema Q, de Barton, e RMR, de Bieniawski. Surgida por volta de 1960, a geoestatística permite analisar fenômenos que não são totalmente aleatórios e cujos valores dependem de sua posição no espaço. Este trabalho consistiu em desenvolver modelos numéricos tridimensionais a partir da aplicação da classificação de maciço rochoso pelo sistema RMR (Rock Mass Rating), utilizando técnicas geoestatísticas para a interpolação em regiões não amostradas. Os objetivos foram identificar feições e zonas com características geotécnicas de menor qualidade, verificar a representatividade dos modelos numéricos frente as estruturas geológicas mapeadas, observar a influência de fatores de redução nas classificações de RMR e analisar a variação de resultados quando são usadas malhas de amostragem diferentes. Os resultados obtidos foram satisfatórios, tanto do ponto de vista geoestatístico quanto do ponto de vista geotécnico. Foram delimitadas as regiões de atenção e identificadas as principais estruturas e feições geológicas nos modelos de RMR. Foi possível avaliar a influência dos fatores de redução na classificação de maciço, assim como a influência da malha de amostragem nos resultados estatísticos, geoestatísticos e de interpolação. Os dados amostrais foram comparados entre si e evidenciaram a importância e superioridade da classificação por RMR em detectar as principais feições e características geológicas, assim como demonstraram a variação da sensibilidade quando se utiliza diferentes fatores de redução. / A safe dam installation and its project feasibility, necessarily, depends on knowing, to the clearest, the geotechnical rock substrate characteristics in the installation place. Therefore, geotechnical investigation campaigns are undertaken to elaborate geological and geomechanics models, which may present errors due to natural variability, insufficient sampling, two-dimensional interpretation and subjectivityes. Aiming to decrease the subjectivism in the interpretations regarding the geomechanics characteristics, the rock mechanics makes use of rock mass classifications such as Q, by Barton, and RMR, by Bieniawski. Developed about 1960, geostatistics allows to analyze phenomena not completely random and whose values depend on its special position. This study consisted in developing three-dimensional numerical models from the rock mass assessment with RMR, using geostatistics to interpolate data in regions without sampling. The objectives were to identify features and zones with poor geotechnical characteristics, to evaluate how representative the numerical models are compared to the mapped geological structures, to observe the influence of reduction factors in the RMR classification and to analyze the variation of the results when different sampling grids are used. The obtained results were satisfactory, both in the geostatistical and geotechnical aspects. The critical regions were delimitated and the main geological structures and features were identified in the RMR model. It was possible to evaluate the influence of the reduction factors in the rock mass assessment, as well as the influence caused by the sampling grids in the statistic, geostatistics and interpolated results. Sampled data were compared and demonstrated how important and how superior the RMR assessment is to detect the major features and geological characteristics, as well as to demonstrate how sensitive the variation of the results is when different reduction factors are used.

Os sistemas de classificação maciços rochosos e as redes neurais artificiais possuem diversas similaridades. Existem características que estão presentes nos dois tipos de sistemas: bases de dados são usadas para o seu desenvolvimento; e pesos são parte da representação do conhecimento. Os principais sistemas de classificação geomecânicas (Sistema Q e RMR) podem ser escritos como representações neurais locais. Tais representações permitem uma melhor compreensão do processo de classificação e identificação de padrões realizado pelas classificações convencionais. Experimentos convencionais foram realizados com modelos de redes neurais não-supervisionados. Os modelos não supervisionados permitiriam uma melhor compreensão da distribuição dos dados no espaço de feições. Um modelo supervisionado para escavações subterrâneas em todo domínio do espaço de feições. Importantes relações entre características foram encontradas. / Rock mass classification systems and artificial neural networks have several similarities. There is some characteristics present in both systems: data bases are used in they development, and weights are part of the knowledge representation. The main rock mass classification systems (Q-system and RMR) can be written as local neural network representations. This representation helps a better understanding of the pattern classification and identification process made by the conventional classifications. Computational experiments were made with unsupervised and supervised neural networks models. Unsupervised models allow a better understanding of the data in the feature space. A supervised model allow to make a mapping of the support type used in underground excavation in all feature space domain. Important relations between domain regions characteristics and type of support used were found.

A implantação segura e a viabilidade de um projeto de barragem dependem de se conhecer, com o máximo de clareza, as características geotécnicas do substrato rochoso do local de implantação. Para tanto, são realizadas campanhas de investigação geotécnica para a elaboração de modelos geológicos e geomecânicos, os quais podem apresentar erros devido à variabilidade natural, amostragem insuficiente, interpretação bidimensional e subjetividade das interpretações. Visando diminuir a subjetividade das interpretações acerca das características geomecânicas, a mecânica das rochas utiliza classificações de maciço rochoso, tais como sistema Q, de Barton, e RMR, de Bieniawski. Surgida por volta de 1960, a geoestatística permite analisar fenômenos que não são totalmente aleatórios e cujos valores dependem de sua posição no espaço. Este trabalho consistiu em desenvolver modelos numéricos tridimensionais a partir da aplicação da classificação de maciço rochoso pelo sistema RMR (Rock Mass Rating), utilizando técnicas geoestatísticas para a interpolação em regiões não amostradas. Os objetivos foram identificar feições e zonas com características geotécnicas de menor qualidade, verificar a representatividade dos modelos numéricos frente as estruturas geológicas mapeadas, observar a influência de fatores de redução nas classificações de RMR e analisar a variação de resultados quando são usadas malhas de amostragem diferentes. Os resultados obtidos foram satisfatórios, tanto do ponto de vista geoestatístico quanto do ponto de vista geotécnico. Foram delimitadas as regiões de atenção e identificadas as principais estruturas e feições geológicas nos modelos de RMR. Foi possível avaliar a influência dos fatores de redução na classificação de maciço, assim como a influência da malha de amostragem nos resultados estatísticos, geoestatísticos e de interpolação. Os dados amostrais foram comparados entre si e evidenciaram a importância e superioridade da classificação por RMR em detectar as principais feições e características geológicas, assim como demonstraram a variação da sensibilidade quando se utiliza diferentes fatores de redução. / A safe dam installation and its project feasibility, necessarily, depends on knowing, to the clearest, the geotechnical rock substrate characteristics in the installation place. Therefore, geotechnical investigation campaigns are undertaken to elaborate geological and geomechanics models, which may present errors due to natural variability, insufficient sampling, two-dimensional interpretation and subjectivityes. Aiming to decrease the subjectivism in the interpretations regarding the geomechanics characteristics, the rock mechanics makes use of rock mass classifications such as Q, by Barton, and RMR, by Bieniawski. Developed about 1960, geostatistics allows to analyze phenomena not completely random and whose values depend on its special position. This study consisted in developing three-dimensional numerical models from the rock mass assessment with RMR, using geostatistics to interpolate data in regions without sampling. The objectives were to identify features and zones with poor geotechnical characteristics, to evaluate how representative the numerical models are compared to the mapped geological structures, to observe the influence of reduction factors in the RMR classification and to analyze the variation of the results when different sampling grids are used. The obtained results were satisfactory, both in the geostatistical and geotechnical aspects. The critical regions were delimitated and the main geological structures and features were identified in the RMR model. It was possible to evaluate the influence of the reduction factors in the rock mass assessment, as well as the influence caused by the sampling grids in the statistic, geostatistics and interpolated results. Sampled data were compared and demonstrated how important and how superior the RMR assessment is to detect the major features and geological characteristics, as well as to demonstrate how sensitive the variation of the results is when different reduction factors are used.

<p>Determination of the subsurface geology is very important for the rock quarry industry. This is primarily done by drilling and mapping of the surface geology. However in Sweden the bedrock is often completely covered by Quaternary sediments making the prediction of subsurface geology quite difficult. Incorrect prediction of the rock-mass quality can lead to economic problems for the quarry. By performing geophysical measurements a more complete understanding of the subsurface geology can be determined. This study shows that by doing 2D-parallel data sampling a 3D inversion of the dataset is possible, which greatly enhances the visualization of the subsurface. Furthermore the electrical resistivity technique together with the induced polarization method proved to be very efficient in detecting fracture frequency, identification of major fracture zones, and variations in rock-mass quality all of which can affect the aggregate quality. With this technique not only the rock-mass quality is determined but also the thickness of the overburden. Implementation of geophysics can be a valuable tool for the quarry industry, resulting in substantial economic benefits.  </p>

Slope stability plays an important role in rock engineering. During the design, construction and post design phases of rock slope stability, engineers and geologists need to pay close attention to the rock conditions within the rock slope to prevent slope failures, protect employees and maintain economic profit. This dissertation is based on a general four step procedure to construct and maintain rock slope stability with confidence. These four steps include field investigations, material testing and rock strength database, slope modelling and slope monitoring. The author provides past, present and alternatives methods for each step for the introduced slope stability procedure. Specific topics within each step are investigated displaying results, recommendations and conclusions. Step one involves data collection during field investigations for rock slope design. Orientation of rock core during drilling programs has become extremely pertinent and important for slope stability and underground mining operations. Orientation is needed to provide essential data to describe the structure and properties of discontinuities encountered during the design process to understand favourable and unfavourable conditions within a rock slope and underground openings. This chapter examines and discusses the limitations and benefits of four methods of obtaining borehole discontinuity orientations from drilling programs including clay-imprint, ACT I, II, III Reflex, EZY-MARK, and OBI/ABI Televiewer systems. Results, recommendations and conclusions are provided in this study. During step two to maintain rock slope stability, a rock strength database was created and used to correlate and compare RQD values to rock abrasion, shear strength and other rock characterization methods. Rock abrasion plays a significant role in geotechnical design, tunneling operations and the safety of foundations from scour; however, rock abrasion can be used to develop higher confidence in important parameters such as RQD and hardness. More rock abrasivity research is needed to provide a more accurate and compatible method for all subsurface material properties used in mining and civil engineering projects. This report will provide simple correlations relating abrasion resistance to RQD, UCS, Geological Strength Index (GSI) and Rock Mass Rating (RMR) of metamorphic rock. Results, discussions and conclusions are provided. Step 3 to determine rock slope stability entails utilizing computer modeling to predict failure conditions and wear rock mass properties. Computer modeling and slope monitoring for rock slopes have become essential to assess factor of safety (FOS) values to predict slope instability and estimate potential failure. When utilizing computer models, the limit equilibrium method (LEM) provides FOS values according to force and moment equilibrium; the shear strength reduction (SSR) technique calculates FOS using stress- and deformation-based analyses. Currently, both methods are prevalent in the engineering industry and applied by geotechnical engineers to analyze and determine stability in rock slopes for mining and civil engineering projects. Slope modeling techniques are then used to observe slope conditions and predict when slope failure may occur (FOS = 1.0). Comparison, results and conclusions are presented. Lastly, the dissertation (step 4: slope monitoring) will investigate past studies of FOS comparisons, review calculation methods and provide procedures and results using remote sensing data. The main objective of the dissertation is to provide engineers with essential information needed to ensure high confidence in factor of safety predictions and how alternative methods can be utilized. Recommendations, future research and conclusions regarding FOS and slope monitoring are provided within the dissertation.

This thesis presents an engineering geological and geotechnical investigation of the proposed Terrace Opencast Coalmine highwall in the Reddale Valley, Reefton. The proposed pit will target the 4-11m thick No. 4 Seam coal, which exists on the Valley floor beneath outwash gravels and Brunner Coal Measures (BCM) overburden dipping at 15-30° to the northwest. Rock coatings are providing friable sandstone units with protection from weathering in existing cut faces and may contribute to short term pit wall stability. The BCM core was divided into four geotechnical units for rock material testing purposes: unit 1 siltstone, unit 2 carbonaceous mudstone, unit 3 interbedded sandstone and carbonaceous mudstone and unit 4 loose sandstone. The average results for units 1-3 gave classifications within the medium to high porosity (9-13%) and dry density (2250-2470kg/m³) ranges, and medium to medium high slake-durability Id2 values (72-94% retained). Unit 4 (loose sandstone) recorded very low dry density (1694 kg/m³) and slake-durability Id2 (9%) average values. Strength testing confirmed that the units can be classed as weak rocks, with average UCS values of 12.8-13.7MPa for units 1-3, and for all four units Is(50) from point load testing of 0.26-0.62MPa with low cohesion values (0-6.2MPa) from triaxial testing. Friction angles from triaxial tests gave high values of 32-45°, while direct shear tests established 15° internal friction for bedding planes in carbonaceous mudstone and 37° for a high angle defect in interbedded sandstone/carbonaceous mudstone. The average Young's modulus values ranged from 0.82 to 10GPa, and Poisson's ratio between 0.39 and 0.50. Eight scanline defect surveys established that the major discontinuities in existing cut faces consist of high angle tension joints, shallow dipping bedding, and faults related to regional uplift. The defect orientations from the scanlines located in the southwest were significantly different from those in the northeast, and may be due to the faults that cross the Valley. In general the majority of defects displayed low persistence (less than 3m), were clean and tight, and had low joint roughness coefficients (JRC less than 6). Joint wall compressive strengths gave an average of 32MPa, but were affected by case-hardening on weathered faces. The results from the 8 drill holes analysed show that 37% of core was within the excellent rock quality designation class (RQD = 90-100%), while 29% was in the very poor quality rock (RQD = 0-25%). A semi-confined aquifer in the outwash gravels that will drain into the proposed pit was found to have a transmissivity of 58m²/day and hydraulic conductivity of 3.1 x 10⁻⁵ m/s. Kinematic feasibility assessment determined an optimum highwall orientation of 65° dip to 120° (dip direction), which is within at least 20° of the coal seam strike. The likelihood of planar, wedge or toppling failure depends on whether the structural conditions are similar to those encountered in the southwest or northeast scanlines, as well as the persistence of the defects present. The occurrence of small scale (less than 1m offset) 'step-up' normal faults, and the three larger faults that cross the valley, all of which are related to regional uplift, will also affect which failure mode will be kinematically feasible. Other crucial slope stability considerations include groundwater inflow from the saturated overburden and bedding parallel failures on the footwall dip slope of the pit. An investigation into case hardening on existing cut faces identified three interconnected rock coatings: iron films, lithobiontic (biological) and clay-dominated crusts. Jarosite was found at sites with abundant pyrite and the oxidation of iron may have been aided by microbial activity. A green algae inhabiting pore spaces approximately 1mm below the surface was noted beneath an iron film and it is suggested to be similar to that found in arid environments. Although lithobiontic and clay-dominated crusts did not provide the weathered surface with any additional strength, they were observed to form relatively quickly (from months to less than 5 years) and will aid short term stability by providing the batters with protection from weathering processes. This project concluded that the overburden material in the proposed highwall can be expected to behave like weak rock and in some cases (such as the loose sandstone) can be expected to have soil characteristics. Highwall stability is more likely to be affected by substantial inflows of groundwater than highly persistent joint sets. Establishment of the highwalls in their final position in the early mining stages will enable development of rock coatings that are expected to aid short and long term stability.

In this thesis, the results of a number of rock mass classification systems applied to Dim-higway tunnel study area are presented. The tunnel ground was classified according to Rock Mas Rating (RMR), Modified Rock mass Rating (M-RMR), Rock mass quality (Q), Geological Strength Index (GSI) and New Austrian Tunneling Method (NATM). Dim Tunnel has a horse-shoe shape, with a diameter of 10 meters and maximum overburden thickness of 70 meters. During studies, the geological and geotechnical characteristics of the rock mass along the Dim Tunnel route were investigated. The main objective of rock mass classifications carried out in this study was to obtain adequate data that could be used in future excavation and support-design studies. In order to accomplish this task, literature survey was carried out, followed by a comprehensive field study and laboratorytesting. Field studies involved detailed discontinuity surveys of the exposed rock mass at the surface and on the cores taken within 10-20 meters of the borehole above the tunnel. A geological map and a geological cross-section along the tunnel axis were also prepared. Finally, correlations between the results of the rock mass classification systems were made carrying out statistical analyses for the Dim Tunnel study area. The results obtained from the RMR and M-RMR classifications indicate that M-RMR system estimates better rock mass quality ratings at the upper bounds of the rock mass condition, but worst ratings at the lower bounds (RMR is less than 40) as also suggested by the previous studies.

Hundreds of thousands of landslides occur every year around the world impacting on people's lives. Monitoring techniques able to foresee imminent collapse and provide a warning in time useful for action to be taken are essential for risk reduction and disaster prevention. Acoustic emission (AE) is generated in soil and rock materials by rearrangement of particles during displacement or increasing damage in the microstructure preceding a collapse; therefore AE is appropriate for estimation of slope deformation. To overcome the high attenuation that characterise geological materials and thus to be able to monitor AE activity, a system called Slope ALARMS that makes use of a waveguide to transmit AE waves from a deforming zone to a piezoelectric transducer was developed. The system quantifies acoustic activity as Ring Down Count (RDC) rates. In soil applications RDC rates have been correlated with the rate of deformation, however, the application to rock slopes poses new challenges over the significance of the measured AE trends, requiring new interpretation strategies. In order to develop new approaches to interpret acoustic emission rates measured within rock slopes, the system was installed at two trial sites in Italy and Austria. RDC rates from these sites, which have been measured over 6 and 2.5 years respectively, are analysed and clear and recurring trends were identified. The comparison of AE trends with response from a series of traditional instruments available at the sites allowed correlation with changes in external slope loading and internal stress changes. AE signatures from the limestone slope at the Italian site have been identified as generated in response to variations in the groundwater level and snow loading. At the conglomerate slope in Austria, AE signatures include the detachment of small boulders from the slope surface caused by the succession of freeze-thaw cycles during winter time. Consideration was also given to laboratory testing of specific system elements and field experiments. A framework towards strategies to interpret measured acoustic emission trends is provided for the use of the system within rock slopes.