Scanline Method Research Articles

ANALYSIS OF ROCK QUALITY AND LANDSLIDE POTENTIAL IN NORTH JERING HILLS, SLEMAN, YOGYAKARTA

The study was to identify the direction and type of potential landslides, as well as assess the rock quality on the slopes of North Jering Hills. The scanline method, consisting of stretching the meter, was employed to collect data on the plane of failure. The information gathered encompassed the direction, slope level, and condition of the unsuccessful plane, aligned with the parameters in the RMR table of Bieniawski from 1989. Following the collation of data, kinematic and rock mass quality analysis was undertaken using stereographic projection and RMR parameter weighting respectively. The kinematic analysis revealed a planar avalanche type on the slope. The RMR value of the research location's slope was 80, classifying it as good rock.

Defining the degree of fracturing in fault zones: implications in the study of landslide susceptibility

This contribute describes the fracture network of rock masses along a section normal to two parallel faults between Claviere and Cesana Torinese (Western Alps), applying traditional scanline method, topological analysis and geomechanical classification by Geological Strength Index. Based on the variation of fracture intensity defined by topology, the aim of this study is to estimate the width of the zones with a more pervasive fracturing around the faults. These zones could be considered as a reference to define the average “buffer zone” of the analysed fault system in landslide susceptibility studies at regional scale. In the studied area, the fracture intensity is derived from topological analysis (i.e., total length of fractures per unit area – P21 values) abruptly increases in areas 200 to 400 metres-wide adjacent to the considered faults with values of fracture intensity greater than 20 m/m2 and 70 m/m2 respectively. The geomechanical GSI classification underlies a coherent variation in the degree of fracturing in the analysed areas close to the faults.

How a basement fault has controlled Pb- Zn ore deposition within the Zagros Fold-Thrust Belt? a focus on remote sensing approaches

ABSTRACT The Zagros fold and thrust belt as one of the structurally complex areas have been considered chiefly only for hydrocarbon reserves, despite having other mineral deposits like the Surmeh lead and Zinc mine. This study was conducted in the Fars region, one of the structural zones in the Zagros, to detect hydrothermal alteration minerals associated with Pb–Zn mineralization and fracture distribution using ASTER, Landsat 8, and Sentinel 2 satellite imagery. Using different algorithms and approaches, we demonstrate the interesting distribution of Pb-Zn-related mineral deposits controlled by structures on different scales. These methods included the spectral band ratios and spectral angle mapping for alteration detection and manual extraction of structural lineaments (i.e. fault and fractures) from ETM+. Also, an augmented circular scanline method, along with areal sampling, was used to prepare a fracture intensity map of the area. According to the results, the intersection of NW-SE and N-S trending fracture sets are promising areas for Pb-Zn-related mineral exploration. These fracture sets are likely associated with the main Karebas tear fault and its horsetail splay terminal. The findings of this study were validated by field observation of the Pb-Zn deposit and its related mineral associations in the area.

Potensi longsor berdasarkan analisis kinematik pada area low wall PT. Bukit Asam Tbk, site Tanjung Enim, Sumatera Selatan

PT. Bukit Asam Tbk is an open-pit coal mining company in Muara Enim, Soutgh Sumatra. In open-pit mining activities, slope stability analysis is carried out to evaluate the mine in order to create a safe mining process. Several types of slope failure are associated with geological structures. This research was conducted to identify the type of landslides in the low wall area of Pit X PT. Bukit Asam Tbk and determine the slope stability factor based on discontinuity data using the scanline method at 8 observation points that represent the lithology of the low wall area. Methods used in this research is kinematic analysis, slope stability analysis on plane slide types and wedge. Based on the kinematic analysis, it was identified that the Pit X low wall area has the potential for plane and wedge type landslides with a relatively stable slopes.

Slope Mass Rating (SMR) Classification for Rock Slope Stability and Geohazard Vulnerability Assessment

Quantitative classification from the Slope Mass Rating (SMR) has introduced an empirical assessment for rock slope stability rating. This stability classification enables us to foreseethe magnitude and susceptibility of rock mass failure towards adjacent infrastructure and human life. In this study, the stability of quarry rock slope was classified using SMR classification system and kinematic stability analysis before being correlatedwith geohazard vulnerability assessment. Geological formation study with site geographical survey from aerial photogrammetry technique provided comprehensive data for the study area. Fieldwork to evaluate the SMR assessment parameters was conducted by discontinuity mapping using scanline method. In-situ evaluation of rock mass such as rebound surface hardness and discontinuity characterization was carried out with rock material sampling for laboratory testing. Kinematic stability analysis presented an estimation for the direction and mode of rock slope failure. The SMR classification that constitutes geomechanics attributes had introduced the global stability rating of rock mass structure, thus facilitating the prediction of potential failure magnitude. Hence, the integration of these stability indications provides sufficient empiricalestimation for geohazard vulnerability zoning for the studied area.

FRACTURE ANALYSIS AND RESERVOIR POTENTIAL OF EXPOSED EOCENE SUCCESSIONS ALONG KOHAT-ORAKZAI TRANSACT KHYBER PAKHTUNKHWA, NW PAKISTAN

The present research work is primarily focusing on fracture analysis of exposed Eocene limestone to estimate the reservoir potential by Monte Carlo Techniques. The methodology implemented is the scanline method which were used for fracture data collections during field work. Three stations were selected for fracture data which consists of 30 scanlines for comprehensive petrophysical properties i.e., fracture density, porosity, and permeability. The computer software was used for interpretation of fracture orientation data. The interpretation demonstrates two prevailing fracture sets existing in the study area which have average NE and NW strike. However, the correlation between their properties is documented based on charts. The consequence specifies that the correlation between density and porosity is variable although the density and permeability is linear. The qualitative classification was based on NFR system analyzed for the reservoir potential which shows very defective correlation whereas fractures provide flexible assistance and does not offer significant additional porosity and permeability. Thus, it occurs from type 4 to type 3 NFR system of classification.

Comparison of Scanline and Photogrammetry Survey for Natural Fracture Analysis, Study Case: Jatiluhur Formation and Subang Formation, Bogor

This research tries to compare the result of fracture measurement using the scanline as conventional method and photogrammetry method to understand the advantages of each method. This comparison is important to understand the benefit of using the photogrammetry for fracture study compared to the conventional method. The study area is located at three fractured outcrops of Jatiluhur Formation and Subang Formation at Cipamingkis river, Bogor. Two hundred fracture data from the scanline method and 215 aerial photos were collected for the analysis. The analysis found there are three main fracture sets in the study area, namely the Northwest – Southeast (NW-SE), Northeast – Southwest (NE-SW), and East-West (E-W). When measured at the same location, no significant difference in the orientation of the fracture sets can be found between both methods. However, the two different methods give a significantly different result on the fracture density calculation (P10). This difference was caused by the lithological characteristic variation, where it influences the ability to identify fracture from a distance. Additionally, the photogrammetric method enables the better identification of shear fractures and joints pattern that associated with the fold. Therefore, this study concludes that both methods are complementing each other on the natural fracture study. The scanline method is optimal for fracture density measurement, while photogrammetry is better for identification of fracture orientation and pattern in a relatively larger area.

Descriptive and quantitative analysis of fracture systems in a carbonate rock mass complex

The study area is located in the Franconian Alb in Southern Germany and is an Upper Jurassic, karstified and fractured, regularly bedded carbonate rock mass with thin marl interlayers. Structurally, these deposits are heterogeneous and a classification into structural types is striven for in this study. The structural classification is based on discontinuity and fault characteristics gained from field work. The study area is considered an analogue for Germanys most productive deep geothermal reservoir horizon in the South German Molasse Basin. The aim of the field study is to describe and quantitatively analyse the different structural types, and to optimize the scanline method for a specific geological setting to gain comprehensive information with regard to fracture permeability and rock mass behaviour. The structural types are described in terms of discontinuity orientation and density, rock strength, and fault characteristics. To optimize the scanline method for the field study additional discontinuity attributes were added. One of these accessory attributes, the existence of discontinuity lags, will be discussed. It occurs when vertical and sub-vertical fractures cross sedimentary layers and continue with a small horizontal displacement in the next sedimentary layer. The results of this study are used to improve derived fracture networks with respect to thermo-hydro-mechanical models in the geothermal sector. Following article discusses the first results of the above-mentioned field study.

Lineament mapping for a part of the Central Sulaiman Fold\u2013Thrust Belt (SFTB), Pakistan

This study aims to analyze the lineaments using the field data and a remote sensing approach, to describe their relationship with the folds, faults, and regional tectonic stress of the central Sulaiman Fold-Thrust Belt. Joint data, from nine anticlines, has been collected using the scanline method and classified into three sets (JS1, JS2, and JS3) based on their geometrical relationships. Lineaments extracted from the 30 m digital elevation model have been classified subsequently into three lineament sets (LS1, LS2, and LS3) based on the azimuths from the corresponding joint sets. A very high correlation coefficient (rs = 0.97), between the azimuths of the field joints and the remotely sensed lineaments, has been observed which validates that the lineaments are the regional representation of the local field joints. The geometrical relationship of the lineament sets with the fold hinges indicates that the older LS1 and LS2 are strongly related to the regional folding episode, while the younger LS3 is a result of local shears. The chronological interpretation of the deformational events responsible for the lineament sets is constrained by the presence of the Kingri Fault, which induces a strike-slip component within the study area. Furthermore, the controls on the joint and lineament sets, established using multivariate statistics to decipher the effects of lithological and structural contrasts on the lineament density, reveal that an increase in the lineament density can be attributed to the competence and thickness of the rock units as well as the variable local stresses across the different folds. Based on the orientations of these lineament sets, the cumulative direction of the compressive event in the NW-SE direction (310–320) coincides with the regional stress direction of the SFTB.

Fracture distribution in a folded fluvial succession: The Puig-reig anticline (south-eastern Pyrenees)

Sedimentary rocks of foreland fold-and-thrust belts typically undergo intensive fracturing as folds grow. The resulting fracture networks can present significant variations depending on the distribution of sedimentary facies and the complex structural characteristics of fold-and-thrust belts. The Puig-reig anticline, located in the south-eastern Pyrenees, mainly exposes proximal fluvial deposits in the north limb and medial fluvial deposits in the rest of the anticline. Thus, this anticline constitutes an excellent case study to investigate the main controls on the distribution of fracture networks in folded fluvial deposits, in terms of structural position and lithofacies variations. Outcrops were selected to be representative of different structural positions, from the fold hinge to its limbs, and of a variety of the main lithofacies, from proximal to medial fluvial deposits. Fracture data were acquired using the linear scanline method. The results indicate that the anticline rocks have been affected by four sets of fractures. The north limb is dominated by thick conglomerate bodies with interlayered sandstones deposited from unconfined flash floods and wide-shallow channel streams in the proximal fluvial fan, and presents large fracture spacing and low fracture intensity but relatively large fracture length and aperture. The crest and the crest-limb transition zones are mainly characterised by interlayered conglomerates, sandstones, siltstones and clays, deposited from braided channel streams and overbanks in the medial fluvial fan, and present fractures with relatively high fracture intensity and variable fracture length and aperture. The south limb, composed of channel filling sandstone layers and stable overbank fine deposits in the medial fluvial fan, is characterised by low fracture intensity and small fracture length and aperture. Based on multiple linear regression analysis, fracture intensity is mainly controlled by the structural position, bedding thickness and lithological associations, with relatively more intense fracturing in thin sandstone layers with multiple interlayers of fine deposits in the anticline crest. The fracture length mainly depends on bedding thickness and is affected lithological associations. The fracture apertures are mainly controlled by lithofacies, with relatively higher apertures affecting conglomerate bodies. The results of this study are relevant for characterising similar systems in the subsurface, where data is scarce.

Development and application of UAV-SfM photogrammetry for quantitative characterization of rock mass discontinuities

Remote sensing techniques (e.g., terrestrial laser scanning and digital photogrammetry) have been developed and applied rapidly in recent years for identification and analysis of rock mass characteristics. A direct validation of these digital measurements against well-constrained datasets obtained from conventional survey methods is reported here. A high-resolution digital outcrop model (DOM) generation method for rock exposures based on unmanned aerial vehicle (UAV) photogrammetry integrated with a structure from-motion (SfM) technique was introduced. A digital procedure based on mathematical algorithms for discontinuity detection, trace mapping and quantitative discontinuity characterization was established. The proposed method was applied to two rock slopes (from Greece and China) and fundamental discontinuity parameters, i.e., the orientation, number of sets, trace length, set spacing, linear frequency, areal frequency and areal intensity were statistically extracted and calculated. Their values were compared with carefully planned manual measurements, i.e., individual discontinuity measurements, scanline method, and window sampling method on the same sites. The results of two sites showed that most deviations are less than 5° for dip direction and dip angle, 0.13 m for exposed discontinuity length, 0.37 m for set spacing, 0.09 m-1 for linear frequency, 0.06 m-2 for areal frequency, and 0.15 m-1 for areal intensity. These deviations are reasonable and acceptable, which confirmed the reliability and accuracy of the developed method. With improved efficiency and workability comparing to conventional methods especially in difficult surveying environments, the UAV-SfM Photogrammetry can potentially become a routine method for on-site rock mass characterization.

New rock mass classifications for limestone of the Woyla group and its empirical relationship in Aceh Province, Indonesia

The rock mass characteristic study, including RMR89, GSI, and RMR14 and their empirical relationships, had been conducted at ten slopes in Aceh Province, Indonesia. This study aims to determine the RMR89, RMR14 and GSI, as well as develop the empirical relationships among those rock mass classifications especially for limestone of the Woyla group. The scan-line method has been adopted in the collection of RMR and GSI data from the slope faces that consist of geological structures, condition of joints, groundwater, and mechanical parameters of intact rock. The regression analysis was utilised to produce the empirical connection of RMR89 with GSI and new RMR14 by plotting those data in graph and trend-line to produce the empirical relationship. The results revealed that beddings, joints, and minor fault system on the slopes determined the quality of rock mass. RMR89 for limestone in our study area were 58–64 or classified as fair to good, whilst the RMR14 were 61.7–67.7 or categorised as good. The RMR14 were just 1.3–5.7 points higher than RMR89. Besides, GSI value was in the range from 49.3 to 54.1. The empirical correlation between RMR89 and GSI was more likely similar to the previous study; however, the empirical relationship between RMR14 and RMR89 was different and it revealed a lower value compared to other rocks.

Maximize mining exploitation efficiency of the quarry: a case study

Nowadays, the dimension stone industry performs a crucial role in the world economy. Accordingly, dimension stone quarries’ importance grows due to their different applications in various construction, building, and decorative industries. Some issues threaten this industry and provide a financial risk that should be taken into account to make the smallest possible risk for investment. The presence of discontinuities in the rock mass has a key function as far as it concerns the overall quality of in situ rock blocks. It impacts the feasibility of dimension stone quarries and overall mine exploitation efficiency. Therefore, it is recommended to survey discontinuities and rock blocks and estimate the average geometry of a rock block, including the shape and size, before mining the benches to maximize mining exploitation efficiency and minimize waste ore production. This investigation aims to survey the discontinuities of the limestone quarry mine located in Josheghan, Iran, to determine and calculate rock blocks’ suitable geometry and an extraction’s direction for active mine benches. For this purpose, the scanline method was applied to survey discontinuities in seven active benches. 3DEC software was used to indicate discontinuities and model the rock blocks for all active benches. It was concluded that the benches’ cutting line make a 13.14 degree with the discontinuities main’s direction. The result of this study proved that by changing the direction of mining and extraction for active mine benches, the unnecessary waste production would decrease. The production rate with the recommended extraction direction will increase by about 1.13% compared to the current extraction direction, which makes 13.14 degrees with the discontinuities main’s direction. Currently, bench seven recorded the minimum production rate, which is 97.60; by applying the new extraction’s direction, it is predicted that this bench will achieve a 99.83 production rate. Consequently, it is concluded by improving the production rate, exploitation efficiency would increase considerably.

Cleat properties of the Tanjung Agung coalfield, South Sumatra Basin: implications to fluid flow

Observation of the coal cleats of the Muara Enim Formation in Tanjung Agung coalfield aims to characterize the cleat properties and interpret their implications for fluid flow. This study used the scanline method to measure cleat attributes in the form of orientation, aperture, spacing, filler, and cleat connectivity. The face cleat was dominated by NE-SW direction as an indication of the effect of paleostress, while butt cleat with NW-SE direction indicated the effect of stress release. The presence of one major fault and three minor faults trending NW-SE in the mine pit is interpreted as the main controlling factor for cleat development in the study area. These cleats have an aperture ranging from 0.4 - 2.3 mm, good connectivity, and are not filled, so they are considered to be analogous to fluid flow paths with transition and turbulent flow types with relatively NE-SW direction.

Automatic and Manual Fracture-Lineament Identification on Digital Surface Models as Methods for Collecting Fracture Data on Outcrops: Case Study on Fractured Granite Outcrops, Bangka

Three-dimensional outcrop models, or Digital Surface Models (DSMs), have proved their capacity in many geoscience studies. Along with the advantage in the rapid acquisition, DSMs are capable of creating virtual models of fractured outcrops to be interpreted for further analysis. This paper reports the DSM robustness by comparing the result of fracture-lineament measurement using DSMs and discusses the possible causes of error that might occur. The first method applied in this study is the scanline method to collect fracture data directly from outcrops, measuring more than 1,400 fracture data. The second method is applying fully automatic and manual fracture identification by optimizing hill-shaded DSMs. Two well-exposed granite outcrops in Bangka, Indonesia, are designed for the pilot area. Structure-from-Motion (SfM) photogrammetry is utilized to generate the DSMs, where a series of aerial images are captured using Unmanned Aerial Vehicle (UAV). The images are then processed into hill-shaded DSMs to be automatically analyzed following the algorithm in PCI Geomatics software and manually assessed. The textures of DSMs are also used in fracture identification through RGB filtering as the third method. The results show that the semiautomatic measurement using RGB-filtering texture has the closest pattern to the scanline data compared to the hill-shaded DSM method. The differences rely on several conditions, such as the geometry and texture of the outcrops. Eventually, methods of fracture identification using DSM are expected to be capable as options in preliminary fracture data collecting on outcrops, especially when the scanline is unable to be performed.

Comparison and Performance Evaluation of Boundary Fill and Flood Fill Algorithm

In computer graphics, there are many polygon filling algorithms available like as inside and outside test, scan line method, boundary fill, flood fill, edge fill and fence fill algorithm. In this paper we focus on the flood fill and boundary fill algorithms for both four connected as well as eight connected pixels. This research paper shows the comparison and performance evaluation of boundary fill and flood fill algorithms with consideration of running time in C-language. And also shows the how stack affects the performance of the system due to overflow of buffer later on JAVA implementation with queue improves the system performance for large polygon. It also shows the literature review of various papers use the fill algorithm on different applications, some proposed the new and enhanced polygon fill algorithms.

Geological Structural Surface Evaluation Model Based on Unascertained Measure

The surrounding rock structure plane survey is the basis for mine geological structure evaluation and stability of surrounding rock. On the basis of the unascertained measurement theory and scanline method, the surrounding rock stability of the underground geological structure plane in Lingbao Luoshan Gold Mine is evaluated. First, according to the structural plane five grading standards, the 9 single-index measure functions are constructed. Second, the information entropy is used to determine the weight of each indicator. Accordingly, a multi-index comprehensive measure evaluation vector is established. Finally, the confidence level is used to determine the structural plane stability level. Results show that surrounding rock grades of middle sections of R1, R2, and R3 are Grades III, IV, and IV in Lingbao Luoshan Gold Mine, respectively. The evaluation grade is consistent with the actual situation of the mine, and strengthening the surrounding rock support for the middle sections of R2 and R3 is necessary. According to engineering practice, the evaluation model of the underground structure of metal mines established in this study has a practical value.

Discrete Fracture Network Modelling in Triassic–Jurassic Carbonates of NW Lurestan, Zagros Fold-and-Thrust Belt, Iran

In this study, discrete fracture network (DFN) modelling was performed for Triassic–Jurassic analogue reservoir units of the NW Lurestan region, Iran. The modelling was elaborated following a multi-scale statistical sampling of the fracture systems characterising the analysed succession. The multi-scale approach was performed at two different observation scales. At the macro-scale, a digital outcrop analysis was carried out by means of a digital line-drawing based on camera-acquired images, focussing on the distribution of major throughgoing fractures; at the meso-scale, the scan line method was applied to investigate the background fractures of the examined formations. The gathered data were statistically analysed in order to estimate the laws governing the statistical distribution of some key fracture set attributes, namely, spacing, aperture, and height. The collected dataset was used for the DFN modelling, allowing the evaluation of the relative connectivity of the fracture systems and, therefore, defining the architecture and the geometries within the fracture network. The performed fracture modelling, confirmed, once again, the crucial impact that large-scale throughgoing fractures have on the decompartmentalization of a reservoir and on the related fluid flow migration processes. The derived petrophysical properties distribution showed in the models, defined the Kurra Chine Fm. and, especially, the Sehkaniyan Fm. as good-quality reservoir units, whereas the Sarki Fm was considered a poor-quality reservoir unit.

Real-time lane detection and tracking for autonomous vehicle applications

This article proposes an improved lane detection and tracking method for autonomous vehicle applications. In real applications, when the pose and position of the camera are changed, parameters and thresholds in the algorithms need fine adjustment. In order to improve adaptability to different perspective conditions, a width-adaptive lane detection method is proposed. As a useful reference to reduce noises, vanishing point is widely applied in lane detection studies. However, vanishing point detection based on original image consumes many calculation resources. In order to improve the calculation efficiency for real-time applications, we proposed a simplified vanishing point detection method. In the feature extraction step, a scan-line method is applied to detect lane ridge features, the width threshold of which is set automatically based on lane tracking. With clustering, validating, and model fitting, lane candidates are obtained from the basic ridge features. A lane-voted vanishing point is obtained by the simplified grid-based method, then applied to filter out noises. Finally, a multi-lane tracking Kalman filter is applied, the confirmed lines of which also provide adaptive width threshold for ridge feature extraction. Real-road experimental results based on our intelligent vehicle testbed proved the validity and robustness of the proposed method.

CLUSTERING SLOPE STABILITY USING DEM LINEAMENT EXTRACTION AND ROCK MASS RATING IN PANGKALAN KOTO BARU,WEST SUMATRA, INDONESIA

Clustering slope stability in the Pangkalan Koto Baru, West Sumatra has become one of priority in disaster management. The method used for this study is using a combination of structural lineament analysis, scanline with window sampling and Rock mass rating (RMR) calculations. The analysis results of the fourteen observed slope sites showed significant outcome, which seen in the structural lineament show dominant trend from northwest-southeast, which also correlate from the measurement of discontinuity by using scanline with window sampling. From RMR calculation, value showed range between 17 - 42 which belonged to class V (Very Poor Rock) - class III (Medium Rock ). Integration data of structural lineament, scanline method and RMR analysis suggested that 1 slope included in the very poor rock category, 12 slopes are poor rock category, and 1 slope in the medium rock category. So, it can be ascertained that most of the slopes will potentially be prone to landslides.