# Strata Control by Roof Blasting for Bord and Pillar Mining Method in Mechanized Depillaring Panels
## 1 Introduction
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**Parameters** & **Panel Details** \\ \hline Name of the coal seam & Bagdona Coal Seam (BCS) \\ Boreholes in/around the panel & CMPS-2, 22 \\ Grade of coal & G-6 and G-8 \\ Degree of gassiness & II \\ Seam thickness & 1.77 m \(\approx\) 1.8 m \\ Gradient of seam & 1 in 20 along level and 1 in 16 along dip \\ Status of overlying and underlying coal seams & Overlying LWS at a parting of 50 m has been extracted by the caving method \\ Overlying structures & Rainy Season Nalla \\ Roof & 1.6 m—sandy shale, 1 m—medium-gained sandstone, 3 m—carbonaceous \\ Immediate roof & 1.6 m—Sandy shale \\ Immediate floor & Sandy shale with thin sandstone \\  & Within the Panel- Local faults with a throw of 1.6 m, slips, cracks \\ Geological Disturbance & Rise Side of Panel- Fault F7B with a throw of 10-20 m \\  & Dip Side of Panel- Fault F7A with a throw of 28 m \\ Panel extent & From 63L to 69L and 6D to 33D between faults F7A (upthrow 30 m) and F7B \\  & (downthrow 30 m) \\ Size of pillar & 39.5 m \(\times\) 35 m (center to center), 35.7 m \(\times\) 31.2 m (corner-to-corner) during \\  & development by drilling-blasting with 3.8 m gallery width \\ Number of pillars & 114 (may change depending upon slips and faults exposed during the \\  & development of the virgin area in the panel) \\ Panel length & 27 pillars (27 \(\times\) 35 + 4= 949 m) \\ Panel width & Maximum 5 pillars (39.5 \(\times\) 5 + 4 = 201.5 m) but vary from 1 to 5 pillars \\ Extraction height & 1.80 m \\ Present width of the gallery by drilling-blasting & 3.8 m during development by drilling-blasting \\ Depth cover & 190 m to 266 m \\ RMR of seam & 50.4 \\ Compressive strength of coal & 23 MPa (as per NIRM report November 2012) \\ Existing Support during development by drilling & Quick setting cement grouted roof bolts at 1.2 m \(\times\) 0.8 m grid pattern \\ Incubation Period & 24 months \\  & North & Mine boundary \\ Boundary & South & Panel No. W7 and W7 X-Cut \\ East & Panel No. E8 \\  & West & Shobbapur abandoned coal mine \\ Existing support system & Quick setting cement grouted roof bolts at 1.2 m \(\times\) 0.8 m grid pattern \\ Waterlogging and fire & Free from waterlogging and fire \\ \hline \end{tabular}
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Table 1: Geo-mining conditions of the panel. in reducing stress concentrations and maintaining stability in high-stress environments. [PERSON] et al. [8] discuss hydraulic fracturing technology to manage hard roof conditions, demonstrating its potential to enhance roof stability by reducing stress and improving permeability. [PERSON] et al. [9] examine mining-induced strata movement and roof behavior, providing insights into the importance of monitoring and analyzing strata to optimize roof support systems and enhance safety. [PERSON] et al. [10] propose innovative intelligent mining technologies and real-time monitoring for deep coal mines, addressing challenges related to high geological stress and complex strata behavior. [PERSON] et al. [11] investigate roof strata behavior and support resistance for ultra-thick longwall top coal caving panels, offering solutions for maintaining safe working conditions in high-stress environments. [PERSON] and [PERSON] [12] explore the design of longwall top coal caving for thick coal seams with poor surrounding strata, providing recommendations for effective support systems and safety protocols. [PERSON] et al. [13] examine controlled fracturing of overlying strata to ensure the safe extraction of thick coal seams. [PERSON] et al. [14] investigate roof presplitting techniques in non-pillar coal mining, focusing on reducing stress concentrations in hard roof conditions. Finally, [PERSON] et al. [15] present safety and high-recovery mechanisms for the initial mining of complex coal seams with thick, hard roofs, emphasizing the need for advanced support systems and innovative technologies for safe and efficient operations.