Browsing by Author "Senarathna, TMB"

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Analysis of efficiency and impact by deck charging patterns on rock blasting at Aruwakkalu Limestone Quarry, Sri Lanka
(Department of Earth Resources Engineering, 2023-08-28) Surangani, RKH; Shanthilal, S; Sandaruwan, DLCD; Chaminda, SP; Samarakoon, KGAU; Senarathna, TMB
There is a potential to enhance both the efficiency and the quantity of explosives in limestone excavation utilising deck charge patterns in the Aruwakkalu limestone quarry in Sri Lanka. To achieve this a series of combinations with ANFO and deck charge patterns were simulated using a numerical analysis software named JKSimblast – 2D bench. This study entails simulating and validating the existing blasting geometry in the rock blasting practice. The fragmentation curves of the real world blast events were analysed and plotted using an AI platform called “Streyos”. Subsequently, the blasting geometry was optimised by adjusting the spacing and burden with different charge amounts. A comparison was made between the explosive energy distribution figures of the simulated blast with optimised blasting geometry and the deck charging blast series. To simulate the limestone condition for the rock mass, throughout different simulations, the rock specific gravity (SG) was defined as 2.6. Optimised spacing and burden for a 10.3 m deep and 72 mm diameter blast hole pattern were found as 2.9 m and 2.4 m respectively, ensuring favourable conditions with controlled ground vibration (5 mms-1) and air blast overpressure (120 dB). The optimal configuration for minimising boulder formation in the upper section of the hole was 23.17 kg of ANFO quantity per hole with a two-charge deck pattern.
item: Conference-Full-text
Correlations between durability, mineralogy and strength properties of limestone
(Department of Earth Resources Engineering, University of Moratuwa, 2021-12) Senarathna, TMB; Janith, SHMPK; Dassanayake, ABN; Chaminda, SP; Jayawardena, CL; Dissanayake, DMDOK; Jayawardena, CL
Durability is used to depict the obstruction of rock to weathering and the pace of events of such changes. Wetting and drying cycles cause evaluation of physical changes and slaking behaviour of rocks, and that can be appraised by the slake durability test. Correlations between durability, mineralogy, and other physical-mechanical properties are different with the rock. Physical and mechanical characteristics of High-grade limestone samples and Lowgrade limestone samples from the Aruwakkalu mine were determined according to ASTM standard methods. X-ray diffractometer (XRD) analysis and scanning electron microscope (SEM) analysis were used to determine the mineralogical contents of the studied samples. Regression analyses were performed between the slake durability index and the physicalmechanical properties of limestones to identify the best wetting and drying cycle to assess the relationships. Differences between the physical, mechanical properties, and mineralogical contents of High-grade limestone and Low-grade limestone were also identified from the laboratory test results. Finally, this study will help to understand any rock engineering problem relating to durability, mineralogy, and other physical-mechanical properties of areas with limestone.