Parallel Session 1A

Accurate detection of discontinuities is critical to determine rock mass features such as block geometry, joint orientation, and potential failure surfaces, which govern structural stability in mining and geotechnical applications. Manual methods of detecting discontinuities are often time-consuming, expose personnel to hazardous situations, and are susceptible to biased judgement. In response, image processing techniques like image segmentation have been increasingly adapted to detect discontinuities from rock outcrop images. This study evaluates the performance of traditional and machine learning segmentation methods to identify a higher accuracy workflow for discontinuity detection and the following methodology was employed: RGB rock outcrop images were manually annotated to establish ground truth masks, pre-processed with noise-reduction filters and then processed using traditional Gradient-based operators, Canny edge detection, thresholding and machine learning approaches, U-net, Holistically-Nested Edge Detection (HED), and Segment Anything Model (SAM). The performance of these methods was quantified by evaluating the Boundary F1 score against the ground truth masks. Among discontinuity-based traditional segmentation methods, on a scale of 0 to 1, Canny edge detection with morphological gradient achieved F1 scores of 0.194 and 0.196, while among similarity-based segmentation methods, dilation of eroded threshold images achieved F1 scores of 0.264 and 0.202. For machine learning methods, SAM outperformed the other methods by achieving F1 scores of 0.752 and 0.632, but caused over-segmentation in highly discontinuous regions. The findings highlight the significance of combining computationally efficient traditional methods with targeted preprocessing for low-resource settings and underscore the trade-off between machine learning accuracy and its infrastructural demands.

Fracture toughness is an important parameter for evaluating the resistance of a material to crack initiation and propagation. Although Mode I and Mode II fracture toughness have been studied under quasi static loading, their behavior under dynamic loading remains insufficiently understood. Previous research shows that compressive and tensile strength, as well as Mode I fracture toughness, are influenced by loading rate and often result in different fracture patterns. Based on this, it is expected that Mode II fracture toughness may also be sensitive to loading rate. Additionally, rock anisotropy, which affects crack propagation, may influence fracture behavior under varying loading conditions. This study first used Finite Element Method simulations with the J integral to evaluate geometry related factors. Then, Mode II fracture toughness tests were conducted at different loading rates using the Short Core in Compression method. A servo controlled hydraulic system and a Split Hopkinson Pressure Bar were used to apply quasi static and dynamic loading, respectively. The effects of loading rate and anisotropy on Mode II fracture toughness and crack propagation were examined.

The Sohagpur Coalfield in District Shahdol, Madhya Pradesh, India represents a critical mining zone where extensive coal extraction activities have significantly altered the natural hydrological balance between groundwater and surface water systems. The study encompasses primary data collection from 45 monitoring wells and 12 surface water bodies across the coalfield, supplemented by secondary data analysis from government agencies and mining corporations. Hydrochemical parameters including pH, electrical conductivity, total dissolved solids, heavy metals, and coal-derived contaminants were analyzed to understand the extent of mining-induced modifications to natural water systems. Results indicate significant groundwater depletion in active mining zones with average water table decline of 2.3 meters annually, coupled with deteriorating water quality characterized by elevated sulfate concentrations (450-680 mg/L) and heavy metal contamination exceeding permissible limits (1). Surface water bodies show seasonal fluctuations with reduced baseflow contributions from groundwater, particularly during post-monsoon periods when groundwater-surface water exchange rates decreased by 35-40% compared to pre-mining conditions (2). The research establishes a comprehensive understanding of mining-induced alterations to hydrological systems, providing critical insights for sustainable water resource management and environmental restoration strategies in coal mining regions of central India.

Beachrocks are intertidal coastal sediments formed mainly through carbonate cementation, and these sedimentary structures can be seen along the coastlines of Sri Lanka due to the prevailing tropical climate. Beachrock occurrences and formations in Sri Lanka are underexplored, despite their potential for biomimetic ground improvement. This study investigates the formation mechanism and engineering relevance of beachrocks in Chilaw and Uswetakeiyawa, focusing on the mineralogical and elemental characteristics to support nature-based ground improvement applications. Analytical methods employed included Scanning Electron Microscopy with Energy Dispersive X-ray Spectroscopy (SEM-EDX), Fourier Transform Infrared Spectroscopy (FT-IR), and X-ray Diffraction (XRD). The evidence suggests that beachrocks in both the localities consist mainly of quartz grains cemented by High Magnesium Calcite (HMC) with micritic coating and scalenohedral terminations, show evidence of carbonate cementation by mixed marine and meteoric water, and biological activity. Contrasting with Aragonite-rich beachrocks in Southern Sri Lanka, these findings highlight regional variations in cementation and formation mechanisms. Further exploration is recommended with additional geochemical analysis, tests of strength, petrographic thin sections, and geochronological dating, to help establish an integrated basis for understanding beachrock formation and its application to nature-based ground improvement techniques.

Sri Lanka possesses a diverse portfolio of industrial minerals, yet systematic evaluations of their export performance and competitiveness remain limited. This study analyzes the export trends of graphite, quartz, mica, and mineral sands between 2000 and 2023 using data from UN Comtrade, World Integrated Trade Solution (WITS). The analysis incorporates trade quantities, inflation-adjusted unit values, and Revealed Comparative Advantage (RCA) Analysis to assess Sri Lanka’s competitiveness in global markets. Results show that graphite exports, despite increasing unit prices (US$ 373–2,250/MT), have declined in volume since 2015 due to supply constraints and rising competition from synthetic and flake graphite. Quartz emerges as the most stable performer, with consistent growth in both export volume and value, supporting electronics and solar industries. Mica exports peaked in 2014 but declined sharply, though recent increases in mica powder exports highlight niche potential. Mineral sand displayed volatility: titanium concentrates surged to 87.4 KMT in 2021 and collapsed in 2023 to 2.4 KMT, while zirconium concentrates recorded a strong recovery in 2023. RCA analysis confirms Sri Lanka’s strong comparative advantage in graphite and quartz, moderate advantage in mica, and mixed performance in mineral sands. The findings suggest that while value-added processing has improved long-term competitiveness, Sri Lanka must balance policy restrictions on raw exports with market realities. Modernization of mining technologies, strengthening value chains, and flexible export strategies are recommended to sustain growth and enhance global competitiveness.

Sri Lanka’s mining sector holds strong economic potential but faces growth limitations due to procedural delays and regulatory inefficiencies. This study conducts a detailed legislative and process analysis of Sri Lanka's mining regulations, focusing on licensing workflows managed by the Geological Survey and Mines Bureau (GSMB) and related authorities. Through stakeholder interviews, surveys, and case study reviews, the research identifies challenges such as document submission redundancies, paper-based systems, coordination gaps between institutions, and a lack of transparency and standardization. Using insights from international best-practices and the Resource Governance Index (RGI), the study proposes an optimized licensing framework. This framework incorporates business process reengineering and e-governance principles, emphasizing inter-agency coordination, critical path analysis, and streamlined document handling to reduce approval times and improve accountability. The proposed reforms aim to enhance information accessibility, procedural clarity, and investor confidence, ultimately supporting timely initiation of mining activities. The paper offers actionable recommendations for policymakers and institutional leaders to guide digital transformation and governance improvements within Sri Lanka’s mining sector, aligning it with global standards while addressing local procedural bottlenecks and governance challenges.

Tailings storage facilities (TSFs) are essential components of mining operations, designed to contain byproducts from mineral processing. However, their structural failure can lead to catastrophic environmental damage, loss of life, and long-term socioeconomic disruption. Continuous, high-resolution monitoring is therefore vital for early detection of instability and informed risk management. In this study, 161 ascending Sentinel-1 acquisitions were processed using the SBAS-InSAR technique within OpenSARLab, a cloud-based platform that enables scalable, reproducible analysis of satellite radar data. Despite challenges posed by dense tropical vegetation and frequent rainfall, applying a coherence threshold of 0.6 yielded broad spatial coverage, with a mean coherence of 0.70 across 249 observation points. This allowed for reliable displacement retrieval even in vegetated zones. Mean LOS velocities ranged from −7.46 to +2.83 cm/yr, with 94% of the area showing subsidence. The embankment crest was the most mobile, averaging −4.67 cm/yr, with cumulative deformation reaching −0.42 m in the west sector by 2025. Time-series analysis revealed stepwise accelerations coinciding with heavy rainfall events (≥150–250 mm/month), suggesting rainfall-modulated creep rather than imminent failure. To improve early-warning capabilities, future work should integrate GNSS control points and detailed construction records to calibrate thresholds and strengthen causal interpretation.

In recent years, induced seismicity has increased, posing risks to underground facilities. Despite various mitigation efforts, their effectiveness remains limited due to the complex and heterogeneous stress states of natural geological structures. To address this challenge, this study proposes enhancing fracture stiffness in fault damage zones as a mitigation strategy. Using discrete element method (DEM) simulations, we show that increased stiffness can reduce seismic moments and radiate energy to around 40% of their original values, regardless of fracture orientation. The effect is stronger near the fault core, with higher fracture density and smaller fracture sizes, further amplifying the reduction. These findings offer a conceptual basis for mitigating seismic hazards through targeted modification of fracture properties.

This final segment invites reflections from presenters and attendees, synthesizing key insights from the session. The session chair will formally conclude the discussion by summarizing thematic threads, highlighting interdisciplinary contributions, and outlining potential collaborative directions.