Mobile QR Code QR CODE : Journal of the Korean Society of Civil Engineers

  1. ์ˆœ์ฒœ๋Œ€ํ•™๊ต ํ† ๋ชฉ๊ณตํ•™๊ณผ ์„์‚ฌ๊ณผ์ • (Sunchon National University ยท try.young2401@gmail.com)
  2. ์ข…์‹ ํšŒ์› ยท ํ•œ๊ตญ์ „๋ ฅ๊ณต์‚ฌ ์ „๋ ฅ์—ฐ๊ตฌ์› ์†ก๋ณ€์ „์—ฐ๊ตฌ์†Œ ์ฑ…์ž„์—ฐ๊ตฌ์›, ๊ณตํ•™๋ฐ•์‚ฌ (KEPRI ยท hhryu82@kepco.co.kr)
  3. ์ข…์‹ ํšŒ์› ยท ๊ต์‹ ์ €์ž ยท ์ˆœ์ฒœ๋Œ€ํ•™๊ต ํ† ๋ชฉ๊ณตํ•™๊ณผ ๊ต์ˆ˜ (Corresponding Author ยท Sunchon National University ยท shchong@scnu.ac.kr)



์ง€ํ•˜๋งค์„ค๋ฌผ, ์ „๊ธฐ๋น„์ €ํ•ญ ํƒ์‚ฌ, ์ •๋Ÿ‰ํ™”๋œ ๋ฉ”์‰ฌ, ์ „๊ธฐ์ €ํ•ญ ์ˆ˜์น˜ ํ•ด์„ ๋ชจ๋“ˆ, ์ „์œ„ ๋ถ„ํฌ
Underground structure, Electrical resistivity survey, Generalized mesh, Electrical resistance numerical module, Electric potential distribution

1. ์„œ ๋ก 

์ธ๊ตฌ ๊ณผ๋ฐ€ํ™”๋กœ ์ธํ•œ ๋ณต์žกํ•œ ๋„์‹œ์‹œ์„ค์„ ํšจ์œจ์ ์œผ๋กœ ์šด์˜ํ•˜๊ธฐ ์œ„ํ•œ ์ง€ํ•˜๊ณต๊ฐ„ ํ™•์ถฉ ์‚ฌ์—…์€ ๊ธฐ์กด์— ์„ค์น˜๋œ ์ง€ํ•˜์‹œ์„ค๋ฌผ(์ง€ํ•˜๋„๋กœ, ๊ณต๋™๊ตฌ, ์ „๋ ฅ๊ตฌ)์˜ ์ ๊ฒ€๊ณผ ๊ต์ฒด, ๊ทธ๋ฆฌ๊ณ  ์ƒˆ๋กœ์šด ์ง€ํ•˜์‹œ์„ค์„ ์„ค์น˜ํ•˜๋Š” ๋ชฉ์ ์œผ๋กœ ์ตœ๊ทผ๊นŒ์ง€ ์ง„ํ–‰๋˜์–ด ์˜ค๊ณ  ์žˆ๋‹ค. ํ•˜์ง€๋งŒ ์ฒด๊ณ„์ ์ด์ง€ ๋ชปํ•œ ์ง€ํ•˜ ์ •๋ณด ๊ด€๋ฆฌ๋กœ ์ˆ˜๋„๊ด€ ๋ˆ„์ˆ˜ ๋ฐ ํ†ต์‹ ์„  ๋‘์ ˆ๊ณผ ๊ฐ™์€ ์ง€ํ•˜ ์•ˆ์ „์‚ฌ๊ณ ๊ฐ€ ๋Š์ž„์—†์ด ๋ฐœ์ƒํ•˜๊ณ  ์žˆ๋‹ค. ์ด๋Ÿฌํ•œ ์ง€ํ•˜์‹œ์„ค๊ณผ ๊ด€๋ จ๋œ ์‚ฌ๊ณ  ์˜ˆ๋ฐฉ์„ ์œ„ํ•ด ์ฒด๊ณ„์ ์ธ ๊ด€๋ฆฌ์‹œ์Šคํ…œ์œผ๋กœ์„œ 3์ฐจ์› ์ง€ํ•˜๊ณต๊ฐ„ ํ†ตํ•ฉ์ง€๋„(Underground Geospatial Information Map)๋ฅผ ๊ตฌ์ถ•ํ•˜์˜€์ง€๋งŒ, 2์ฐจ์› ๋ฐ์ดํ„ฐ๋กœ ์ˆ˜์ง‘๋œ ๊ธฐ์กด ์ง€ํ•˜๋งค์„ค๋ฌผ ์ •๋ณด๋ฅผ 3์ฐจ์›์œผ๋กœ ํ™•์žฅํ•˜๋Š” ๊ณผ์ •์—์„œ ์ ์šฉ๋˜๋Š” ๊ฐ„๋‹จํ•œ ๋ณด๊ฐ„๋ฒ•๊ณผ ์ง€ํ•˜๊ตฌ์กฐ๋ฌผ ์ค€๊ณต ๋„๋ฉด์„ ์ด์šฉํ•œ ๋ณด์กฐ ์ธก๋Ÿ‰์€ ๊ธฐ์กด์— ๋งค์„ค๋œ ๊ฐ์ข… ์‹œ์„ค๋ฌผ๋“ค์˜ ์ •ํ™•ํ•œ 3์ฐจ์› ์œ„์น˜ ์ •๋ณด๋ฅผ ์ œ๊ณตํ•˜๋Š”๋ฐ ์–ด๋ ค์›€์ด ์žˆ์œผ๋ฏ€๋กœ, ์‹œ๊ณต ์ „ ํ˜„์žฅ ์ง€๋ฐ˜์กฐ์‚ฌ๋Š” ํ•„์š”ํ•˜๋‹ค(Kang et al., 2021).

์ผ๋ฐ˜์ ์œผ๋กœ ์ˆ˜ํ–‰๋˜๋Š” ์ง€๋ฐ˜์กฐ์‚ฌ๋Š” ์ง€๋ฐ˜์˜ ์ƒํƒœ๋ฅผ ์ง์ ‘ ํŒŒ์•…ํ•˜๋Š” ์‹œ์ถ”์กฐ์‚ฌ์™€ ๋น„ํŒŒ๊ดด ๋ฌผ๋ฆฌํƒ์‚ฌ ๊ธฐ๋ฒ•์œผ๋กœ ๋‚˜๋ˆ ์ง„๋‹ค. ์‹œ์ถ”์กฐ์‚ฌ๋Š” ์ง€์ •๋œ ๊ตฌ์—ญ์˜ ์‹œ์ถ”๊ณต ์ฃผ๋ณ€ ์ง€๋ฐ˜์˜ ์ƒํƒœ๋งŒ์„ ์ œ๊ณตํ•˜๋ฉฐ, ์ง€๋ฐ˜์กฐ์‚ฌ๊ฐ€ ์ˆ˜ํ–‰๋˜์ง€ ์•Š๋Š” ๊ตฌ์—ญ์€ ์ˆ˜ํ•™์ ์ธ ๋ณด๊ฐ„๋ฒ•์„ ์ด์šฉํ•˜์—ฌ ์ง€๋ฐ˜ ์ƒํƒœ๋ฅผ ์ถ”์ •ํ•˜๋ฏ€๋กœ, ์ด์ƒ๋Œ€ ์กด์žฌ๋ฅผ ํƒ์ง€ํ•˜๋Š”๋ฐ ํ•œ๊ณ„๊ฐ€ ์žˆ๋‹ค(Arifuzzaman and Anisuzzaman, 2022; Sun et al., 2022). ์ง€ํ‘œํˆฌ๊ณผ๋ ˆ์ด๋”(Ground Penetrating Radar; GPR) ํƒ์‚ฌ๋Š” ์ง€ํ•˜์ˆ˜์œ„, ํฌํ™”๋„ ๊ทธ๋ฆฌ๊ณ  ํ•จ์ˆ˜๋น„์™€ ๊ฐ™์€ ์ง€๋ฐ˜ ์ƒํƒœ์— ๋”ฐ๋ฅธ ์ง€๋ฐ˜์˜ ์œ ์ „์œจ์„ ์ด์šฉํ•˜๋ฏ€๋กœ, 1 m ์ด์ƒ ๊นŠ์ด์— ๋งค์„ค๋œ ์ง€ํ•˜๋งค์„ค๋ฌผ ํƒ์ง€์—๋Š” ์ ํ•ฉํ•˜์ง€ ์•Š๋‹ค(Thitimakorn et al., 2016). ํƒ„์„ฑํŒŒ ํƒ์‚ฌ๋Š” ์ง€ํ•˜๋งค์„ค๋ฌผ์˜ ๋ฐฉํ–ฅ, ์œ„์น˜ ๊ทธ๋ฆฌ๊ณ  ํ„ฐ๋„ ์ „๋ฐฉ ์˜ˆ์ธก์— ์‚ฌ์šฉ๋˜์ง€๋งŒ, ์‹ ํ˜ธ ๋ฐœ์ƒ์„ ์œ„ํ•œ ๋ฐœํŒŒ์™€ ๊ธฐ๊ณ„์  ์ถฉ๊ฒฉ์œผ๋กœ ์ธํ•œ ์†Œ์Œ ๋ฌธ์ œ ๋ฐ ์ธก์„ ์„ ์„ค์น˜ํ•˜๋Š”๋ฐ ์–ด๋ ค์›€์ด ์žˆ๋‹ค(Lee et al., 2002; Ezersky, 2017; De la Paz-Bonilla and Vidot-Vega, 2017). ํ•œํŽธ, ์ „๊ธฐ๋น„์ €ํ•ญ ํƒ์‚ฌ๋Š” ์ง€๋ฐ˜์— ๊ด€์ž…๋œ ๋‘ ์ „๊ทน์˜ ์ „์œ„์ฐจ๋ฅผ ์ด์šฉํ•˜์—ฌ ์ „๊ทน ์‚ฌ์ด ๋งค์งˆ์˜ ์ „๊ธฐ์ €ํ•ญ์„ ์ธก์ •ํ•˜๋Š” ๋ฐฉ๋ฒ•์œผ๋กœ ์ „๊ทน์˜ ์„ค์น˜๊ฐ€ ํŽธ๋ฆฌํ•˜๊ณ  ์†Œ์Œ ๋ฌธ์ œ๋„ ์—†์œผ๋ฏ€๋กœ, ์ตœ๊ทผ์— ๋„์‹ฌ์ง€ ๋‚ด ์ง€๋ฐ˜์กฐ์‚ฌ๋ฒ•์œผ๋กœ์จ ์ฃผ๋กœ ์‚ฌ์šฉ๋˜์–ด ์˜ค๊ณ  ์žˆ๋‹ค.

์ „๊ธฐ๋น„์ €ํ•ญ ํƒ์‚ฌ๋Š” 1900๋…„๋Œ€ ์ดˆ์— ๊ฒ‰๋ณด๊ธฐ๋น„์ €ํ•ญ ๊ฐœ๋…์ด ๋„์ž…๋˜๋ฉด์„œ ์ง€ํ•˜๋ฅผ ์ˆ˜ํ‰ ๋‹ค์ธต ๊ตฌ์กฐ๋กœ ๊ฐ€์ •ํ•˜๋Š” 1์ฐจ์› ํƒ์‚ฌ๊ฐ€ ์ˆ˜ํ–‰๋˜์—ˆ๋‹ค. ํ•˜์ง€๋งŒ, ํ•˜๋ถ€ ์ง€๋ฐ˜์„ 1์ฐจ์›์œผ๋กœ ๊ฐ€์ •ํ•œ ๊ฒฝ์šฐ์—๋Š” ์ˆ˜ํ‰์  ์ „๊ธฐ๋น„์ €ํ•ญ ๋ณ€ํ™”๋ฅผ ์ธก์ •ํ•˜์ง€ ๋ชปํ•˜๊ธฐ ๋•Œ๋ฌธ์— ๋ณต์žกํ•œ ์ง€ํ•˜ ๊ตฌ์กฐ๋ฅผ ํ•ด์„ํ•˜๊ธฐ์—๋Š” ํ•œ๊ณ„๊ฐ€ ์žˆ๋‹ค. 1980๋…„๋Œ€ ์ดํ›„์—๋Š” ์ธก์ • ์žฅ๋น„์˜ ์ •๋ฐ€๋„, ์ž๋ฃŒ ํš๋“ ๋ฐ ํ•ด์„ ๊ธฐ์ˆ ์˜ ๋ฐœ๋‹ฌ๋กœ ์ „๊ธฐ๋น„์ €ํ•ญํƒ์‚ฌ๊ฐ€ ํš๊ธฐ์ ์œผ๋กœ ๋ฐœ์ „๋˜๋ฉด์„œ, ์ˆ˜ํ‰๊ณผ ์ˆ˜์ง ํƒ์‚ฌ๋ฅผ ๋™์‹œ์— ์ˆ˜ํ–‰ํ•  ์ˆ˜ ์žˆ๋Š” 2์ฐจ์› ํƒ์‚ฌ๋ฅผ ํฌํ•จํ•œ ๋‹ค์ฐจ์› ์ „๊ธฐ๋น„์ €ํ•ญ ๊ธฐ๋ฒ•์ด ๊ฐœ๋ฐœ๋˜์—ˆ๋‹ค. ์ด์™ธ์—๋„ ๋‹ค์ค‘ ์ฑ„๋„ ๋ฐ ๋‹ค์ค‘ ์ „์„ , ๊ทธ๋ฆฌ๊ณ  ์ž๋™ ์ธก์ • ์‹œ์Šคํ…œ์ด ๋„์ž…๋˜๋ฉด์„œ ๋‹ค์–‘ํ•œ ์ „๊ทน ๋ฐฐ์—ด๋กœ๋ถ€ํ„ฐ ์–ป์€ ๋ฐฉ๋Œ€ํ•œ ์ž๋ฃŒ๋ฅผ ๋‹จ์‹œ๊ฐ„ ๋‚ด์— ์ฒ˜๋ฆฌํ•  ์ˆ˜ ์žˆ๊ฒŒ ๋˜์—ˆ๋‹ค(Nazifi et al., 2022). ๋ฐ์ดํ„ฐ ํš๋“ ๋ฐ ์ฒ˜๋ฆฌ ๊ธฐ์ˆ  ๋ฐœ์ „์€ ๋‹ค์ฐจ์› ํƒ์‚ฌ๋กœ ์–ป์–ด์ง„ ์ „๊ธฐ๋น„์ €ํ•ญ ๋ถ„ํฌ๋ฅผ ์˜์ƒํ™”ํ•จ์œผ๋กœ์จ ์ง€ํ‘œ ํ•˜๋ถ€๋ฅผ ๋ณด๋‹ค ์‰ฝ๊ฒŒ ํŒŒ์•…ํ•  ์ˆ˜ ์žˆ๋Š” ๋ชจ๋ธ์„ ์ œ๊ณตํ•˜์˜€๋‹ค(Lee et al., 2019). ์—ญํ•ด์„ ๊ธฐ๋ฒ•์„ ๊ธฐ๋ฐ˜์œผ๋กœ ๊ฐœ๋ฐœ๋œ 2์ „๊ทน ์ „๊ธฐ๋น„์ €ํ•ญ ํƒ์‚ฌ ๋ฐฉ๋ฒ•์ธ TEPS(Tunnel Electrical resistivity Prospecting System)๋Š” ํ„ฐ๋„ ์ „๋ฐฉ์˜ ๊ทผ๊ฑฐ๋ฆฌ ์˜์—ญ(ํ„ฐ๋„ ์ง๊ฒฝ์˜ 4-5๋ฐฐ์˜ ๋ฒ”์œ„ ๋‚ด)์—์„œ ์ด์ƒ๋Œ€์™€ ๋‹จ์ธต ํŒŒ์‡„๋Œ€์˜ ์กด์žฌ๋ฅผ ํƒ์ง€ํ•˜์˜€๊ณ (Ryu et al., 2011), ๊ธฐ์กด ์ง€ํ•˜๋งค์„ค๋ฌผ์ธ ์ „๋ ฅ๊ตฌ ์œ„์น˜์™€ ๋ฐฉํ–ฅ์„ ์˜ค์ฐจ์œจ 20% ์ด๋‚ด๋กœ ์˜ˆ์ธกํ•˜์˜€๋‹ค(Ryu et al., 2015; Ryu et al., 2017). ๋˜ํ•œ, Yi et al.(2022)๋Š” ํ„ฐ๋„ ๋‚ด๋ถ€์™€ ๊ตด์ฐฉ๋ฉด์— ๋Œ€ํ•œ ์ „๊ธฐ๋น„์ €ํ•ญ ์ˆ˜์น˜ ํ•ด์„ ๋ชจ๋ธ๋ง๊ณผ ์—ญํ•ด์„ ์•Œ๊ณ ๋ฆฌ์ฆ˜์„ ๊ฐœ๋ฐœํ•˜์—ฌ ํ„ฐ๋„ ์ „๋ฐฉ์˜ ์ด์ƒ๋Œ€ ์œ„์น˜์™€ ์ƒํƒœ๋ฅผ ๋ถ„์„ํ•˜์˜€๋‹ค. ํ•˜์ง€๋งŒ, ์ „์œ„ ์ฐจ์ด์— ์˜ํ•ด์„œ ํ˜•์„ฑ๋˜๋Š” ๋“ฑ์ „์••์„ ๊ณผ ์ „๋ฅ˜ํ๋ฆ„์„  ๋ถ„ํฌ๋ฅผ ๊ฒฐ์ •ํ•˜๋Š” ๋ผํ”Œ๋ผ์Šค ๋ฐฉ์ •์‹์€ ๋ฉ”์‰ฌ ํ˜•์ƒ ๋ฐ ๊ฐœ์ˆ˜์— ๋”ฐ๋ผ์„œ ํ„ฐ๋ฏธ๋„ ์ „๊ทน์—์„œ ์ธก์ •๋˜๋Š” ์ „๊ธฐ์ €ํ•ญ๊ฐ’์— ์ง์ ‘์ ์œผ๋กœ ์˜ํ–ฅ์„ ์ฃผ๋ฏ€๋กœ, ์ •๋Ÿ‰ํ™”๋œ ๋ฉ”์‰ฌ๋ฅผ ์ด์šฉํ•˜์—ฌ ์ง€ํ•˜ ๋งค์„ค๋ฌผ์˜ ๊ธฐํ•˜ํ•™์  ์กฐ๊ฑด(์ง€ํ•˜ ๋งค์„ค๋ฌผ์˜ ๋งค์„ค ๊นŠ์ด์™€ ํฌ๊ธฐ, ์ „๊ทน๊ณผ ๋งค์„ค๋ฌผ์˜ ์ƒ๋Œ€์  ์œ„์น˜)์— ๋”ฐ๋ฅธ ์ „๊ธฐ์ €ํ•ญ ์ˆ˜์น˜ ํ•ด์„์„ ์ˆ˜ํ–‰ํ•ด์•ผ ํ•œ๋‹ค.

๋”ฐ๋ผ์„œ, ๋ณธ ์—ฐ๊ตฌ์—์„œ๋Š” ์ƒ์šฉ ์œ ํ•œ ์š”์†Œ ํ”„๋กœ๊ทธ๋žจ์„ ์ด์šฉํ•˜์—ฌ, ์ „๊ทน ์ฃผ๋ณ€๊ณผ ์ง€ํ•˜๋งค์„ค๋ฌผ์— 3์ฐจ์› ๋ฉ”์‰ฌ๋ฅผ ์ •๋Ÿ‰์ ์œผ๋กœ ์ œ์•ˆํ•˜์˜€๋‹ค. ์‹œ๊ฐ„์— ๋”ฐ๋ผ์„œ ์ „๋ฅ˜๊ฐ€ ์ผ์ •ํ•œ ์ •์ƒ ์ƒํƒœ์—์„œ ์ „๊ทน ํ˜•์ƒ์„ ๊ณ ๋ คํ•œ ์˜ˆ๋น„ ์ˆ˜์น˜ ํ•ด์„์„ ์ˆ˜ํ–‰ํ•˜์˜€๊ณ , ์ด๋ก ์‹๊ณผ์˜ ๋น„๊ต๋ฅผ ํ†ตํ•ด์„œ ์ „๊ธฐ์ €ํ•ญ ์ˆ˜์น˜ ํ•ด์„ ๋ชจ๋“ˆ์„ ๊ฒ€์ฆํ•˜์˜€๋‹ค. ์ œ์•ˆ๋œ ์ •๋Ÿ‰ํ™”๋œ ๋ฉ”์‰ฌ๋ฅผ ์ ์šฉํ•˜์—ฌ ์ „๊ทน๊ณผ ์ง€ํ•˜๋งค์„ค๋ฌผ์˜ ๊ธฐํ•˜ํ•™์  ๋งค๊ฐœ ๋ณ€์ˆ˜ ํ•ด์„์— ๋”ฐ๋ฅธ ์ „๊ธฐ์ €ํ•ญ ๋ณ€ํ™”๋ฅผ ๋น„๊ต ๋ฐ ๋ถ„์„ํ•˜์˜€๋‹ค. ์ถ”๊ฐ€์ ์œผ๋กœ, ์ „๊ทน๊ณผ ์ง€ํ•˜๋งค์„ค๋ฌผ ์ฃผ๋ณ€์— ํ˜•์„ฑ๋œ ์ „์œ„์™€ ์ „๋ฅ˜๋ฐ€๋„ ๋ถ„ํฌ๋ฅผ ๊ณ ์ฐฐํ•˜์˜€๋‹ค.

2. ์ด๋ก ์  ๋ฐฐ๊ฒฝ: ์ „๊ทน ํ˜•์ƒ์— ๋”ฐ๋ฅธ ์ „๊ธฐ์ €ํ•ญ ํ๋ฆ„

์ „๊ธฐ๋น„์ €ํ•ญ์€ ๋„๋ฆฌ ์•Œ๋ ค์ง„ 2๊ฐ€์ง€ ๋ฒ•์น™์„ ๊ธฐ๋ฐ˜์œผ๋กœ ์ˆ˜ํ•™์ ์œผ๋กœ ์œ ๋„ํ•  ์ˆ˜ ์žˆ๋‹ค. ๋จผ์ €, ์˜ด์˜ ๋ฒ•์น™(Ohmโ€™s law)์€ ์ผ์ •ํ•œ ์ „๊ธฐ์ €ํ•ญ์„ ๊ฐ–๋Š” ๊ท ์งˆํ•œ ๋งค์งˆ์—์„œ ๋‘ ์ „๊ทน ์‚ฌ์ด์˜ ์ „์œ„์ฐจ๊ฐ€ ์ „๋ฅ˜์— ๋น„๋ก€ํ•˜๋Š” ์ง์ ‘์ ์ธ ๊ด€๊ณ„๋ฅผ ๊ฒฝํ—˜์‹์œผ๋กœ ๋‚˜ํƒ€๋‚ด์—ˆ๋‹ค. ๋˜ํ•œ, ๋งฅ์Šค์›ฐ ๋ฐฉ์ •์‹(Maxwell equation) ์ค‘ ํ•˜๋‚˜์ธ ๊ฐ€์šฐ์Šค ํ”Œ๋Ÿญ์Šค ์ •๋ฆฌ(Gaussโ€™s flux theorem)๋Š” ์ „๊ธฐ์žฅ์œผ๋กœ๋ถ€ํ„ฐ ๋ฐœ์ƒํ•˜๋Š” ์ „ํ•˜์˜ ํ๋ฆ„๊ณผ ๋ถ„ํฌ์— ๊ด€๋ จ์ด ์žˆ๋‹ค. ์ „๊ธฐ์žฅ์ด ๋ณด์กด์ ์ธ ๊ฒฝ์šฐ์— ์˜ด์˜ ๋ฒ•์น™์„ ์ „๋ฅ˜๋ฐ€๋„ J [amps/m2]์™€ ์ „๊ธฐ์žฅ E [V/m]์œผ๋กœ ํ‘œํ˜„ํ•˜๋ฉด Eq. (1)๊ณผ ๊ฐ™๋‹ค.

(1)
$\nabla\bullet J=\nabla(\sigma\bullet E)=0$

์—ฌ๊ธฐ์„œ, โˆ‡๋Š” ๋ธ ์—ฐ์‚ฐ์ž์ด๋ฉฐ, ฯƒ [1/ฮฉยทm]๋Š” ๋งค์งˆ์˜ ์ „๊ธฐ์ „๋„๋„์ด๋‹ค. ๋‘ ์ ์ „ํ•˜ ์‚ฌ์ด์˜ ์ „์œ„์ฐจ์— ์˜ํ•ด ํ˜•์„ฑ๋œ ๋“ฑ์ „์œ„์„ ์„ ๊ฒฐ์ •ํ•˜๋Š” ๋ผํ”Œ๋ผ์Šค ๋ฐฉ์ •์‹์€ ์ผ์ •ํ•œ ์ „๊ธฐ์ „๋„๋„ ์กฐ๊ฑด์—์„œ ๋‹ค์Œ๊ณผ ๊ฐ™์ด ํ‘œํ˜„๋  ์ˆ˜ ์žˆ๋‹ค.

(2)
$\nabla\bullet J=(\nabla\sigma\bullet E+\sigma\bullet\nabla E)=\nabla^{2}V=0$

Eq. (2)๋ฅผ 2๊ณ„ ์˜ค์ผ๋Ÿฌ-์ฝ”์‹œ ๋ฏธ๋ถ„๋ฐฉ์ •์‹(2nd Euler-Cauchy equation)์œผ๋กœ๋ถ€ํ„ฐ ์ •ํ•ด๋ฅผ ๊ตฌํ•˜๊ณ , ๊ฒฝ๊ณ„ ์กฐ๊ฑด(๋ฌดํ•œ๋Œ€์˜ ๊ฑฐ๋ฆฌ์—์„œ ์ „์œ„ V โ†’ 0)์„ ์ ์šฉํ•˜๋ฉด ๋‹จ์ผ ์ „๊ทน์˜ ์ „์œ„ V ๋ณ€ํ™”์— ๋Œ€ํ•œ Eq. (3)๋ฅผ ์–ป์„ ์ˆ˜ ์žˆ๋‹ค.

(3)
$V=\int\dfrac{\rho I}{A_{(z)}}dz$

์—ฌ๊ธฐ์„œ, ฯ [ฮฉยทm]๋Š” ๋งค์งˆ์˜ ์ „๊ธฐ๋น„์ €ํ•ญ์œผ๋กœ ์ „๊ธฐ์ „๋„๋„์˜ ์—ญ์ˆ˜ (= 1/ฯƒ)์ด๋ฉฐ, I [A]๋Š” ๋งค์งˆ ๋‚ด์— ์œ ๋„๋œ ์ „๋ฅ˜, z [m]๋Š” ์ „๊ทน์˜ ์ค‘์‹ฌ์œผ๋กœ๋ถ€ํ„ฐ์˜ ๋–จ์–ด์ง„ ๊ฑฐ๋ฆฌ, ๊ทธ๋ฆฌ๊ณ  A(z) [m2]๋Š” ์ „๊ทน ๋“ฑํ‘œ๋ฉด์ ์œผ๋กœ ์ „๊ทน์˜ ์ค‘์‹ฌ์œผ๋กœ๋ถ€ํ„ฐ ๋–จ์–ด์ง„ ๊ฑฐ๋ฆฌ z์˜ ํ•จ์ˆ˜์ด๋‹ค. ์ „๊ทน ์‚ฌ์ด์—์„œ ๋ฐœ์ƒํ•˜๋Š” ๋งค์งˆ์˜ ํ‰๊ท  ์ „๊ธฐ์ €ํ•ญ์€ ์•„๋ž˜์˜ Eq. (4)๋ฅผ ํ†ตํ•ด์„œ ๊ตฌํ•  ์ˆ˜๊ฐ€ ์žˆ๋‹ค.

(4)
$R=\dfrac{2\bullet\triangle V}{I}$

์—ฌ๊ธฐ์„œ, โงV [V]๋Š” ๋‘ ์ „๊ทน ์‚ฌ์ด์˜ ์ „์œ„์ฐจ๋ฅผ ์˜๋ฏธํ•œ๋‹ค.

์ผ๋ฐ˜์ ์œผ๋กœ, ํ˜„์žฅ ๋ฐ ์‹ค๋Œ€ํ˜• ํฌ๊ธฐ์˜ ์ „๊ธฐ๋น„์ €ํ•ญ ์‹คํ—˜์€ ์ „๊ทน๊ณผ ๋งค์งˆ ์‚ฌ์ด์˜ ์ ‘์ด‰ ๋ฉด์ ์ด ์ž‘๊ณ , ๊ด€์ž…๋œ ์ „๊ทน๋“ค ์‚ฌ์ด์˜ ๊ฑฐ๋ฆฌ๊ฐ€ ์ถฉ๋ถ„ํ•˜๋ฏ€๋กœ ๊ณ„์‚ฐ์ƒ ํŽธ์˜๋ฅผ ์œ„ํ•ด์„œ ๋™์ผํ•œ ํ‘œ๋ฉด์ ์„ ๊ฐ€์ง„ ๋ฐ˜๊ตฌํ˜•์œผ๋กœ ์น˜ํ™˜ํ•˜์—ฌ ์ „๊ธฐ๋น„์ €ํ•ญ์„ ์‚ฐ์ •ํ•œ๋‹ค. ํ•˜์ง€๋งŒ, ์‹ค๋‚ด ์†Œ๊ทœ๋ชจ ํฌ๊ธฐ์˜ ์ „๊ธฐ๋น„์ €ํ•ญ ์‹คํ—˜์€ ์ „๊ทน์˜ ์ง€์˜ค๋ฉ”ํŠธ๋ฆฌ(์ „๊ทน์˜ ๊ด€์ž… ๊นŠ์ด, ๋ฐ˜์ง€๋ฆ„ ํฌ๊ธฐ ๊ทธ๋ฆฌ๊ณ  ์ „๊ทน ์‚ฌ์ด์˜ ๊ฑฐ๋ฆฌ)๋กœ ์ธํ•ด์„œ ๋“ฑ์ „์œ„๋ฉด๊ณผ ์ „๋ฅ˜ ํ๋ฆ„์ด ๋‹ฌ๋ผ์ง€๋ฏ€๋กœ, ๊ถ๊ทน์ ์œผ๋กœ ์ „๊ธฐ๋น„์ €ํ•ญ๊ฐ’์˜ ์˜ค์ฐจ๋ฅผ ์•ผ๊ธฐํ•œ๋‹ค. ๊ธฐ์กด ๋ฌธํ—Œ์—์„œ ์œ ๋„๋œ 4๊ฐ€์ง€ ์ „๊ทน ํ˜•์ƒ(๋ฐ˜๊ตฌ, ์›๊ธฐ๋‘ฅ, ๋ฐ˜๊ตฌํ˜• ํŒ์„ ๊ฐ€์ง„ ์›๊ธฐ๋‘ฅ, ์ฝ˜ํ˜• ํŒ์„ ๊ฐ€์ง„ ์›๊ธฐ๋‘ฅ)์— ๋”ฐ๋ฅธ ์ „๊ทน์˜ ๋“ฑํ‘œ๋ฉด์ ๊ณผ ์ „๋ฅ˜ ํ๋ฆ„, ๊ทธ๋ฆฌ๊ณ  ์ „๊ธฐ์ €ํ•ญ ์ด๋ก ์‹์„ Table 1์— ์ •๋ฆฌํ•˜์˜€๋‹ค(Kim et al., 2023). ๋ณธ ๋…ผ๋ฌธ์—์„œ๋Š” ํ˜„์žฅ ์ „๊ธฐ๋น„์ €ํ•ญ ํƒ์‚ฌ์—์„œ ์ฃผ๋กœ ์‚ฌ์šฉ๋˜๋Š” ์ฝ˜ํ˜• ํŒ์„ ๊ฐ€์ง„ ์›๊ธฐ๋‘ฅ ์ „๊ทน์œผ๋กœ๋ถ€ํ„ฐ ์œ ๋„๋œ ์ด๋ก ์‹๊ณผ ์ „๊ธฐ์ €ํ•ญ ์ˆ˜์น˜ ํ•ด์„ ๊ฒฐ๊ณผ ๊ฐ„์˜ ๋น„๊ต๋ฅผ ํ†ตํ•˜์—ฌ ๊ฐœ๋ฐœ๋œ ๋ชจ๋“ˆ์„ ๋‹ค์Œ ์žฅ์—์„œ ๊ฒ€์ฆํ•˜์˜€๋‹ค.

Table 1. Schematic of Equipotential and Current Flow Line Induced between Two Electrodes Penetrated on the Ground
../../Resources/KSCE/Ksce.2024.44.1.0049/tb1.png

3. ์ „๊ธฐ์ €ํ•ญ ์ˆ˜์น˜ ํ•ด์„ ๋ชจ๋“ˆ ๊ฐœ๋ฐœ

3.1 ์œ ํ•œ ์š”์†Œ ๋ฉ”์‰ฌ ๋ชจ๋ธ๋ง(Finite Element Mesh Modeling)

๋ณธ ๋…ผ๋ฌธ์—์„œ๋Š” ์ƒ์šฉ ์œ ํ•œ ์š”์†Œ ํ•ด์„ ํ”„๋กœ๊ทธ๋žจ์ธ COMSOL Multiphysicsยฎ(2023)๋ฅผ ์‚ฌ์šฉํ•˜์—ฌ, ์ „๊ทน๊ณผ ์ง€ํ•˜๋งค์„ค๋ฌผ์˜ ๊ธฐํ•˜ํ•™์  ๋งค๊ฐœ ๋ณ€์ˆ˜ ํ•ด์„์— ๋”ฐ๋ฅธ ์ „๊ธฐ์ €ํ•ญ ๋ณ€ํ™”๋ฅผ ์ •๋Ÿ‰์ ์œผ๋กœ ๋ถ„์„ํ•˜์˜€๋‹ค. ์ „์œ„์ฐจ๋กœ ์ธํ•œ ์ „๋ฅ˜ ํ๋ฆ„์„ ๋ฐœ์ƒ์‹œํ‚ค๊ธฐ ์œ„ํ•œ ํ”„๋กœ๊ทธ๋žจ์— ๋‚ด์žฌ๋œ DC(Direct Current) ๋ชจ๋“ˆ๊ณผ ์‹œ๊ฐ„์— ๋”ฐ๋ผ ์ „๋ฅ˜์˜ ์„ธ๊ธฐ์™€ ๋ฐฉํ–ฅ์ด ์ผ์ •ํ•œ ์ •์ƒ ์ง๋ฅ˜ ์ƒํƒœ๋ฅผ ๊ตฌํ˜„ํ•˜๊ธฐ ์œ„ํ•œ Electric Currents์˜ Stationary ๊ธฐ๋Šฅ์„ ์‚ฌ์šฉํ•˜์˜€๋‹ค.

๋ฉ”์‰ฌ(mesh) ๋ชจ๋ธ๋ง์€ ํ•ด์„์˜ ์ •ํ™•๋„์™€ ์†Œ์š” ์‹œ๊ฐ„์— ์ง์ ‘์ ์ธ ์˜ํ–ฅ์„ ๋ฏธ์น˜๋ฉฐ, ํŠนํžˆ ๋ถˆ๊ทœ์น™ํ•œ ๋ฉ”์‰ฌ๋Š” ์ „๊ธฐ์ €ํ•ญ๊ฐ’๊ณผ ์ ์ ˆํ•œ ์ „๊ธฐ์žฅ ๋ถ„ํฌ๋ฅผ ํ˜•์„ฑํ•˜๋Š”๋ฐ ๋ฐฉํ•ด๋ฅผ ์•ผ๊ธฐํ•œ๋‹ค. ์ „๊ทน, ์ง€ํ•˜๋งค์„ค๋ฌผ ๊ทธ๋ฆฌ๊ณ  ์ด๋“ค์˜ ์ฃผ๋ณ€์„ ํฌํ•จํ•œ ๋„๋ฉ”์ธ์„ ํšจ์œจ์ ์œผ๋กœ ์ผ์ •ํ•œ ๋ฉ”์‰ฌ๋กœ ํ˜•์„ฑํ•˜๊ธฐ ์œ„ํ•ด์„œ, ํ”„๋กœ๊ทธ๋žจ์— ๋‚ด์žฌ๋œ Mapped์™€ Swept ๊ธฐ๋Šฅ์„ ์‚ฌ์šฉํ•˜์˜€๋‹ค. Mapped ๊ธฐ๋Šฅ์œผ๋กœ ์ „์ฒด ๋„๋ฉ”์ธ์˜ ๊ฒฝ๊ณ„๋ฉด์„ ํ˜•์„ฑํ•˜๊ณ , ๊ฐ ๊ฒฝ๊ณ„๋ฉด์— ๋Œ€ํ•œ ์š”์†Œ๋“ค์˜ ๊ฐœ์ˆ˜๋“ค์„ ์กฐ์ ˆํ•˜์˜€๋‹ค. ๋˜ํ•œ, Swept ๊ธฐ๋Šฅ์„ ์ด์šฉํ•˜์—ฌ, ๋งˆ์ฃผ๋ณด๋Š” ๋‚ด๋ถ€ ๊ฒฝ๊ณ„๋ฉด ์‚ฌ์ด ์š”์†Œ๋“ค์„ ์ƒ์„ฑํ•˜์˜€๋‹ค. Fig. 1์€ ์ „์ฒด ํ•ด์„ ๋„๋ฉ”์ธ์—์„œ ์ „๊ทน ์ฃผ๋ณ€๊ณผ ์ง€ํ•˜๋งค์„ค๋ฌผ์— ์ƒ์„ฑ๋œ ๋ฉ”์‰ฌ๋ฅผ ๋ณด์—ฌ์ค€๋‹ค. ์šฐ์„ , Fig. 1(a)์—์„œ ๋ณด์ด๋Š” ๋ฐ”์™€ ๊ฐ™์ด, ์ „์ฒด ํ•ด์„ ๋„๋ฉ”์ธ ํฌ๊ธฐ๋Š” W 30 mร—H 20 mร—D 30 m๋กœ ํ•˜์˜€๊ณ , ์ง€ํ•˜๋งค์„ค๋ฌผ์€ ๋‘ ๊ฐœ์˜ ์ „๊ทน๊ณผ ์ˆ˜์ง์„ ์ด๋ฃจ๋Š” ๋ฐฉํ–ฅ์œผ๋กœ ๋„๋ฉ”์ธ ๊ฒฝ๊ณ„๋ฉด๊นŒ์ง€ ๋ชจ๋ธ๋ง์„ ํ•˜์˜€๋‹ค. ๋‹ค์Œ์œผ๋กœ, Fig. 1(b)์—์„œ ๋ณด์ด๋Š” ๋ฐ”์™€ ๊ฐ™์ด, ๋„ˆ๋น„ W๋Š” ์ด 4๊ฐœ์˜ ๊ตฌ์—ญ(We, WD, W1, W2)์œผ๋กœ ๋‚˜๋ˆ„์—ˆ๋‹ค. We๋Š” ์ „๊ทน์„ ํฌํ•จํ•˜๋Š” ๊ฒฉ์ž๋กœ 0.05 m/element(์ดํ•˜ m/elt)์˜ ์ผ์ •ํ•œ ์š”์†Œ ๋‹น ํฌ๊ธฐ๋กœ ์กฐ๋ฐ€ํ•˜๊ฒŒ ํ˜•์„ฑํ•˜์˜€์œผ๋ฉฐ, WD๋Š” ์›๊ธฐ๋‘ฅํ˜• ์ง€ํ•˜๋งค์„ค๋ฌผ์˜ ๊ณก๋ฉด ํ˜•์ƒ์„ ์œ„ํ•ด 0.2 m/elt์— ๊ฐ€๊นŒ์šด ์š”์†Œ ํฌ๊ธฐ๋ฅผ ๊ตฌ์„ฑํ•˜์˜€๋‹ค. W1๊ณผ W2๋Š” 0.5 m/elt์— ๊ฐ€๊นŒ์šด ํฌ๊ธฐ๋ฅผ ๊ฐ€์ง€๋„๋ก ๋ฉ”์‰ฌ๋ฅผ ํ˜•์„ฑํ•˜์˜€๋‹ค(WD, W1 ๊ทธ๋ฆฌ๊ณ  W2์˜ ์ „์ฒด ๊ธธ์ด๋Š” ์ง€ํ•˜๋งค์„ค๋ฌผ์˜ ์ง๊ฒฝ, ์ด๊ฒฉ๊ฑฐ๋ฆฌ ๊ทธ๋ฆฌ๊ณ  ๋‘ ์ „๊ทน ์‚ฌ์ด ๊ฑฐ๋ฆฌ์— ๋”ฐ๋ผ ๋ณ€ํ™”ํ•˜์ง€๋งŒ, ๊ฐ๊ฐ์— ๋Œ€ํ•œ ์š”์†Œ ๋‹น ๊ธธ์ด๋Š” ์ผ์ •ํ•จ). ๊ธธ์ด D๋Š” ์ด 2๊ฐœ์˜ ๊ธฐํ˜ธ(D1 ๊ทธ๋ฆฌ๊ณ  We)๋กœ ๊ตฌ์„ฑ๋˜์—ˆ์œผ๋ฉฐ D1์€ ๋„ˆ๋น„ ๋ฐฉํ–ฅ์˜ ์š”์†Œ๋“ค๊ณผ ๋™์ผํ•˜๊ฒŒ 0.5 m/elt์— ๊ฐ€๊นŒ์šด ํฌ๊ธฐ๋กœ ํ˜•์„ฑํ•˜์˜€๋‹ค. ๋˜ํ•œ, Fig. 1(c)์—์„œ ๋ณด์ด๋Š” ๋ฐ”์™€ ๊ฐ™์ด, ๊นŠ์ด H๋Š” ์ด 5๊ฐœ์˜ ๊ตฌ๊ฐ„(H0, H1, WD, H2, ๊ทธ๋ฆฌ๊ณ  H3)์œผ๋กœ ๊ตฌ์„ฑ๋˜์—ˆ๋‹ค. H0๋Š” ์ „๊ทน์˜ ์›๊ธฐ๋‘ฅ ๋ถ€๋ถ„ l(= 0.1 m)๊ณผ ์ฝ˜ ํŒ ๋ถ€๋ถ„ h(= 0.05 m)์œผ๋กœ ๊ฐ๊ฐ 1๊ฐœ์˜ ์š”์†Œ๋กœ๋งŒ ํ˜•์„ฑ๋˜์—ˆ์œผ๋ฉฐ, H1๊ณผ H2๋Š” 0.2 m/elt์— ๊ฐ€๊นŒ์šด ํฌ๊ธฐ๋ฅผ ๊ฐ€์ง€๋Š” ์š”์†Œ๋“ค๋กœ ๊ตฌ์„ฑํ•˜์˜€๊ณ , H3์€ ์ˆ˜์น˜ํ•ด์„์˜ ์†Œ์š”๋˜๋Š” ์‹œ๊ฐ„์„ ์ค„์ด๊ธฐ ์œ„ํ•ด ๋“ฑ๋น„์ˆ˜์—ด์„ ์ด์šฉํ•˜์—ฌ ์ตœ์†Œ 0.2 m/elt์—์„œ ์ตœ๋Œ€ 2.0 m/elt๋กœ ๋ฉ”์‰ฌ์˜ ํฌ๊ธฐ๋ฅผ ์กฐ์ ˆํ•˜์˜€๋‹ค. ๋งˆ์ง€๋ง‰์œผ๋กœ, Fig. 1(d)์—์„œ ๋ณด์ด๋Š” ๋ฐ”์™€ ๊ฐ™์ด ์ „๊ทน ์ฃผ๋ณ€์˜ ๋ฉ”์‰ฌ๋Š” ์ „๊ทน์˜ ๋™์‹ฌ์›์œผ๋กœ ์ธํ•œ ๋ถˆ๊ทœ์น™ํ•œ ๋ฉ”์‰ฌ์˜ ์˜ํ–ฅ์„ ์ค„์ด๊ธฐ ์œ„ํ•ด์„œ ์ „๊ทน์„ ํฌํ•จํ•˜๋Š” We๊ตฌ์—ญ์„ ์ง์„  ํ˜•ํƒœ์˜ ์กฐ๋ฐ€ํ•œ ๊ฒฉ์ž๋กœ ๊ตฌ์„ฑํ•˜์˜€์œผ๋ฉฐ, ์ „๊ทน์„ ๋‘˜๋Ÿฌ์‹ผ ๋ฉ”์‰ฌ๋Š” ์ด 16๊ฐœ์˜ ์š”์†Œ๋กœ ๊ตฌ์„ฑํ•˜์˜€๋‹ค. ์ ‘์ง€์™€ ํ„ฐ๋ฏธ๋„ ์ „๊ทน ์‚ฌ์ด์˜ ์ „์œ„์ฐจ๋กœ ์ธํ•œ ์ „๊ธฐ์ €ํ•ญ ํ•ด์„ ์‹œ๊ฐ„์„ ์ค„์ด๊ธฐ ์œ„ํ•˜์—ฌ ๋‘๊ป˜ 5 mm์ธ ๋‚ด๋ถ€๊ฐ€ ์ฑ„์›Œ์ง€์ง€ ์•Š์€ ํ˜•ํƒœ๋กœ ์ „๊ทน๋“ค์„ ํ˜•์„ฑํ•˜๊ณ , ๋Œ€์‹ ์— ์ „๊ทน์˜ ํ‘œ๋ฉด์— ์ „๊ธฐ์  ๊ฒฝ๊ณ„ ์กฐ๊ฑด(Ground์™€ Terminal)๋“ค์„ ์„ค์ •ํ•˜์˜€๋‹ค. ์•ž์—์„œ ์–ธ๊ธ‰ํ•œ, ์ „๊ทน๊ณผ ์ง€ํ•˜๋งค์„ค๋ฌผ ์ฃผ๋ณ€์— ๊ฐ๊ฐ ํ˜•์„ฑ๋œ ์ •๋Ÿ‰ํ™”๋œ ๋ฉ”์‰ฌ๋ฅผ Fig. 2(e)์— ์ •๋ฆฌํ•˜์˜€๋‹ค.

Fig. 1. Generated Mesh and Generalized Mesh Size Proposed in this Paper: (a) Generated Mesh on the 3D Domain, (b) Top View, (c) Side View, (d) Electrode, (e) Generalized Mesh Size
../../Resources/KSCE/Ksce.2024.44.1.0049/fig1.png../../Resources/KSCE/Ksce.2024.44.1.0049/fig1-1.png

3.2 ์ „๊ธฐ์ €ํ•ญ ์ž…๋ ฅ ๋ฌผ์„ฑ์น˜ ๋ฐ ๋งค๊ฐœ ๋ณ€์ˆ˜

์ „๊ทน์˜ ์ „๊ธฐ๋น„์ €ํ•ญ์€ ํ˜„์žฅ ์ „๊ธฐ๋น„์ €ํ•ญ ํƒ์‚ฌ์—์„œ ์‚ฌ์šฉ๋˜๋Š” ASIS 303 Stainless(ฯe=5ร—10-7ฮฉยทm) ์žฌ์งˆ(Ho and Chu, 1977)๊ณผ ์ง€ํ•˜๋งค์„ค๋ฌผ์˜ ์ „๊ธฐ๋น„์ €ํ•ญ(ฯ2=107ฮฉยทm)์€ PVC๊ด€์˜ ๊ฐ’์„ ์ž…๋ ฅํ•˜์˜€๋‹ค(Ramesh and Arof, 2000). ๋˜ํ•œ, ์ง€๋ฐ˜์˜ ์ „๊ธฐ๋น„์ €ํ•ญ ์ž…๋ ฅ๊ฐ’ (ฯ1=103ฮฉยทm)์€ ๊ฐ„๊ทน๋น„ 0.4์™€ ํ•จ์ˆ˜๋น„๊ฐ€ 14%์ธ ํฌํ™”๋œ ๋ชจ๋ž˜๋กœ ํ•˜์˜€๋‹ค(Yamasaki et al., 2014). ์ „๊ธฐ์  ๊ฒฝ๊ณ„์กฐ๊ฑด์œผ๋กœ ํ„ฐ๋ฏธ๋„ ์ „๊ทน์— 1 V๋ฅผ ๊ฐ€์••ํ•˜์—ฌ ์ ‘์ง€ ์ „๊ทน๊ณผ์˜ ์ „์œ„์ฐจ๋ฅผ 1 V๋กœ ๊ณ ์ •ํ•˜์˜€๋‹ค. ์ „๊ทน๊ณผ ์ง€ํ•˜๋งค์„ค๋ฌผ์˜ ๊ธฐํ•˜ํ•™์  ๋งค๊ฐœ ๋ณ€์ˆ˜๋Š” ๋‘ ์ „๊ทน ๊ฐ„ ๊ฑฐ๋ฆฌ L, ์ง€ํ•˜๋งค์„ค๋ฌผ์˜ ๋งค์„ค ๊นŠ์ด d, ์ง๊ฒฝ D ๊ทธ๋ฆฌ๊ณ  ์ด๊ฒฉ๊ฑฐ๋ฆฌ u๋ฅผ ํฌํ•จํ•˜์—ฌ ์ด 39 ์ผ€์ด์Šค๋“ค์— ๋Œ€ํ•ด์„œ ์ˆ˜์น˜ ํ•ด์„์„ ์ˆ˜ํ–‰ํ•˜์˜€๋‹ค. ์ „๊ทน ํฌ๊ธฐ์™€ ์ „๊ทน ๊ฐ„๊ฒฉ์€ ์‹ค์ œ ํ˜„์žฅ ์ „๊ธฐ๋น„์ €ํ•ญ ํƒ์‚ฌ์—์„œ ์‚ฌ์šฉ๋˜๋Š” ๊ฐ’๋“ค์„ ์‚ฌ์šฉํ•˜์˜€๋‹ค. ๋˜ํ•œ, ๋งค์„ค๋ฌผ ํฌ๊ธฐ์™€ ์ง๊ฒฝ์€ ๋งค์„ค๋œ ์ง€ํ•˜๋งค์„ค๋ฌผ ์ข…๋ฅ˜(์˜ˆ, ํ•˜์ˆ˜๋„๊ด€, ์ƒ์ˆ˜๋„๊ด€, ์ „๋ ฅ๊ตฌ)๋“ค์„ ๋ถ„์„ํ•˜์—ฌ ์„ ์ •ํ•˜์˜€๋‹ค. ์ „๊ทน๊ณผ ์ง€ํ•˜๋งค์„ค๋ฌผ์˜ ๊ธฐํ•˜ํ•™์  ๋งค๊ฐœ ๋ณ€์ˆ˜์™€ ์ „๊ธฐ์  ๋ฌผ์„ฑ์น˜๋“ค์€ Table 2์— ์ •๋ฆฌํ•˜์˜€๋‹ค.

Table 2. Geometry and Electrical Properties of the Electrode and Underground Structure Used in This Study

Parameter

Value

Geometry

[m]

Electrode

Height

Cylinder part l

0.1

Conical tip part h

0.05

Radius r

0.02

Distance L

0.5, 0.9, 1.3, 2, 3, 5

Underground structure

Burial depth d

0.25, 0.5, 1, 2, 3.5

Diameter D

0.3, 0.6, 0.9

Distance from the terminal electrode u

0.45, 0.55, 0.65, 0.75, 0.85, 0.9, 1.5, 2.1, 2.55

Electrical resistivity

[ฮฉยทm]

Electrode ฯe

5ร—10-7

Sandy Soil ฯ1

103

Underground structure ฯ2

107

4. ์ „๊ทน๊ณผ ์ง€ํ•˜๋งค์„ค๋ฌผ์˜ ๊ธฐํ•˜ํ•™์  ํŠน์„ฑ์— ๋”ฐ๋ฅธ ์ „๊ธฐ์ €ํ•ญ ๋ณ€ํ™”

4.1 ์ „๊ธฐ์ €ํ•ญ ์ˆ˜์น˜ ํ•ด์„ ๋ชจ๋“ˆ ๊ฒ€์ฆ: ์˜ˆ๋น„ ์ˆ˜์น˜ ํ•ด์„

์ „๊ทน๊ณผ ์ง€ํ•˜๋งค์„ค๋ฌผ ์ฃผ๋ณ€์— ์ •๋Ÿ‰ํ™”๋œ ๋ฉ”์‰ฌ๋ฅผ ์ ์šฉํ•˜๊ณ , ์ง€ํ•˜๋งค์„ค๋ฌผ์„ ์ง€๋ฐ˜์œผ๋กœ ๊ฐ„์ฃผํ•˜์—ฌ, ์˜ˆ๋น„ ์ˆ˜์น˜ ํ•ด์„์„ ์ˆ˜ํ–‰ํ•˜์˜€๋‹ค(์ง€ํ•˜๋งค์„ค๋ฌผ ๋ฉ”์‰ฌ์— ์ง€๋ฐ˜ ์ „๊ธฐ๋น„์ €ํ•ญ๊ฐ’์„ ์ž…๋ ฅํ•จ). Fig. 2๋Š” ์ฝ˜ํ˜• ํŒ์„ ๊ฐ€์ง„ ์›๊ธฐ๋‘ฅ ์ „๊ทน์— ๋Œ€ํ•œ ์ „๊ธฐ์ €ํ•ญ ์ด๋ก ์‹(Table 1(d) ์ฐธ์กฐ)๊ณผ ์ˆ˜์น˜ ํ•ด์„์„ ๋‘ ์ „๊ทน ์‚ฌ์ด์˜ ๊ฑฐ๋ฆฌ L์— ๋”ฐ๋ผ ๋น„๊ตํ•œ ๊ฒฐ๊ณผ์™€ ํ„ฐ๋ฏธ๋„ ์ „๊ทน ์ฃผ๋ณ€์— ํ˜•์„ฑ๋œ ๋“ฑํ‘œ๋ฉด ์ „๊ธฐ์ €ํ•ญ์„ ๋ณด์—ฌ์ค€๋‹ค. ๋‘ ์ „๊ทน ๊ฐ„ ๊ฑฐ๋ฆฌ L๊ฐ€ ์ฆ๊ฐ€ํ• ์ˆ˜๋ก ์ „๊ธฐ์ €ํ•ญ์€ ์ฆ๊ฐ€ํ•˜์ง€๋งŒ, ์ฆ๊ฐ€๋Ÿ‰์ด ๊ธ‰๊ฒฉํžˆ ๊ฐ์†Œํ•˜๋ฉฐ L=1 m ์ดํ›„๋ถ€ํ„ฐ๋Š” ์ ์ฐจ ์ˆ˜๋ ดํ•˜๋Š” ๊ฒฝํ–ฅ์ด ๋‚˜ํƒ€๋‚ฌ๋‹ค. ์ด๋ก ์‹๊ณผ ์ˆ˜์น˜ ํ•ด์„์—์„œ ์–ป์–ด์ง€๋Š” ๊ฐ๊ฐ์˜ ์ €ํ•ญ๊ฐ’ ์ฐจ์ด๋ฅผ ๋‹ค์Œ ์‹์„ ์ด์šฉํ•˜์—ฌ ์ •๋Ÿ‰์ ์œผ๋กœ ๊ณ„์‚ฐํ•˜์˜€๋‹ค.

(5)
$Error=\dfrac{\left | R^{Theory}-R^{N u m}\right |}{R^{Theory}}$

์—ฌ๊ธฐ์„œ, RThoery [ ]๋Š” ์ด๋ก ์‹์œผ๋กœ ๊ณ„์‚ฐ๋œ ์ €ํ•ญ๊ฐ’, RNum [ ]๋Š” ์ˆ˜์น˜ ํ•ด์„์—์„œ ์–ป์–ด์ง„ ์ €ํ•ญ๊ฐ’, ๊ทธ๋ฆฌ๊ณ  Error [ ]์€ ์˜ค์ฐจ๋ฅผ ์˜๋ฏธํ•œ๋‹ค. Fig. 2(a)์—์„œ ๋ณด์ด๋Š” ๋ฐ”์™€ ๊ฐ™์ด, ์˜ค์ฐจ๋Š” ๋ชจ๋“  ๊ฑฐ๋ฆฌ L์—์„œ 0.005 ๋ฏธ๋งŒ์˜ ๋งค์šฐ ์ž‘์€ ์˜ค์ฐจ๊ฐ€ ๋ฐœ์ƒํ•˜์˜€๋‹ค. ๋ณธ ์—ฐ๊ตฌ์—์„œ ์ œ์•ˆํ•œ ์ •๋Ÿ‰ํ™”๋œ ๋ฉ”์‰ฌ๋Š” ์œ ํ•œ ์š”์†Œ ๋ฉ”์‰ฌ๋กœ ์ธํ•œ ์˜ค์ฐจ๋ฅผ ์ตœ์†Œํ™”ํ–ˆ์œผ๋ฉฐ, ์‚ฌ์šฉํ•œ ์ˆ˜์น˜ ํ•ด์„ ๋„๋ฉ”์ธ ํฌ๊ธฐ๋Š” ๋ฐœ์ƒํ•œ ์ „๋ฅ˜ ํ๋ฆ„๊ณผ ๋“ฑ์ „์œ„๋ฉด ํ˜•์ƒ์ด ๊ฒฝ๊ณ„ ๊ทผ์ฒ˜์—์„œ ์˜ํ–ฅ๋ฐ›์ง€ ์•Š์„ ๋งŒํผ ์ถฉ๋ถ„ํ•จ์„ ํ™•์ธํ•˜์˜€๋‹ค(๊ฒฝ๊ณ„๋ฉด ๊ทผ์ฒ˜์—์„œ ์ „๋ฅ˜ ํ๋ฆ„์ด ๋ฐฉํ•ด๋ฅผ ๋ฐ›๋Š” ์ „๊ธฐ์ ์ธ ๊ฒฝ๊ณ„ ์˜ํ–ฅ์€ Hong et al., 2019 ์ฐธ์กฐ). ๋˜ํ•œ, Fig. 2(b)์—์„œ ์ „๊ทน ์ฃผ๋ณ€์˜ ๋“ฑํ‘œ๋ฉด ์ „๊ธฐ์ €ํ•ญ์€ ์ •์ƒ ์ง๋ฅ˜ ์ƒํƒœ ํ•ด์„์œผ๋กœ ์ธํ•ด ์ „๊ทน์˜ ๋ชจ๋“  ๋ถ€๋ถ„์—์„œ ํ‘œ๋ฉด์— ๋™์ผํ•œ ํ‰๊ท  ์ „๊ธฐ์ €ํ•ญ๊ฐ’์„ ๋ณด์ธ๋‹ค. ์ถ”๊ฐ€์ ์œผ๋กœ, ์ง€๋ฐ˜ ๋‚ด์— ํ˜•์„ฑ๋œ ์ „์œ„์™€ ์ „๋ฅ˜๋ฐ€๋„ ๋ถ„ํฌ๋ฅผ ์ „๊ทน ์ฃผ๋ณ€์—์„œ๋งŒ ํ™•๋Œ€(2.5 mร—5 m)ํ•˜์—ฌ Fig. 3์— ๋„์‹œํ•˜์˜€๋‹ค. ๊ท ์งˆํ•œ ๋งค์งˆ์—์„œ ๋‘ ์ „๊ทน์˜ ์ „์œ„์ฐจ๋กœ ์ธํ•ด ์ „์œ„์™€ ์ „๋ฅ˜๋ฐ€๋„๋Š” ๋Œ€์นญ์ ์ธ ๋ถ„ํฌ๋ฅผ ํ˜•์„ฑํ•œ๋‹ค. ๋˜ํ•œ, ์ „์œ„๋Š” Terminal ์ „๊ทน ๋ฐ”๋‹ฅ๋ฉด์—์„œ ์•ฝ 0.7 m ๋–จ์–ด์ง„ ์ง€์ (= 0.53 V)๊นŒ์ง€ ๊ธ‰๊ฒฉํ•œ ์ „์•• ๊ฐ•ํ•˜๋กœ ์ธํ•ด์„œ ์กฐ๋ฐ€ํ•œ ๋ถ„ํฌ๋ฅผ ๋ณด์ด๋ฉฐ, ๋” ๊นŠ์€ ๊นŠ์ด์—์„œ๋Š” ์ƒ๋Œ€์ ์œผ๋กœ ์ž‘์€ ์ „์•• ๊ฐ•ํ•˜์™€ ๋Š์Šจํ•œ ์ „์œ„ ๋ถ„ํฌ๋ฅผ ๋ณด์ธ๋‹ค. ๋‹จ์œ„ ๋ฉด์ ๋‹น ์ „๋ฅ˜๊ฐ€ ํ๋ฅด๋Š” ์–‘์„ ๋‚˜ํƒ€๋‚ด๋Š” ์ „๋ฅ˜๋ฐ€๋„๋Š” ์ „๊ทน ์˜†๋ฉด์„ ๋”ฐ๋ผ์„œ ํ๋ฅด๋Š” ์ „๋ฅ˜์˜ ์–‘์ด ์ „๊ทน ๋ฐ”๋‹ฅ๋ฉด๋ณด๋‹ค๋Š” ํฌ๋ฏ€๋กœ, ์ „๊ทน์ด ์„ค์น˜๋˜์–ด ์žˆ๋Š” ์–•์€ ๊นŠ์ด์ผ์ˆ˜๋ก ์ „๋ฅ˜๋ฐ€๋„๊ฐ€ ์ƒ๋Œ€์ ์œผ๋กœ ํฌ๊ฒŒ ๋‚˜ํƒ€๋‚ฌ๋‹ค. ์ด์™€ ๊ฐ™์ด, ์˜ˆ๋น„ ์ˆ˜์น˜ ํ•ด์„ ๊ฒฐ๊ณผ ๋ฐ ๋ถ„์„์„ ํ†ตํ•ด์„œ ๋ณธ ์—ฐ๊ตฌ์—์„œ ๊ฐœ๋ฐœ๋œ ์ „๊ธฐ์ €ํ•ญ ์ˆ˜์น˜ ํ•ด์„ ๋ชจ๋“ˆ์˜ ์‹ ๋ขฐ์„ฑ์„ ๊ฒ€์ฆํ•˜์˜€๋‹ค.

Fig. 2. Comparison of Theoretical Electrical Resistance and Numerical Result: (a) Evolution of Electrical Resistance with Respect to Electrode Distance, (b) Selected Isosurface Electrical Resistance
../../Resources/KSCE/Ksce.2024.44.1.0049/fig2.png
Fig. 3. Distributions of (a) Electric Potential, (b) Current Density on the Selected Domain (2.5 mร—5 m). The Current Flows from the Terminal Electrode (Right Side) to the Ground Electrode (Left Side). Case is the Distance between Electrode L=5 m and the Electrical Resistance R=5298 ฮฉ
../../Resources/KSCE/Ksce.2024.44.1.0049/fig3.png

4.2 ์ „๊ทน๊ณผ ์ง€ํ•˜๋งค์„ค๋ฌผ์˜ ๊ธฐํ•˜ํ•™์  ๋งค๊ฐœ ๋ณ€์ˆ˜ ํ•ด์„ ๊ฒฐ๊ณผ

์ง€ํ•˜๋งค์„ค๋ฌผ ๊นŠ์ด์™€ ์ง๊ฒฝ ๊ทธ๋ฆฌ๊ณ  ์ „๊ทน๊ณผ ์ง€ํ•˜๋งค์„ค๋ฌผ ์‚ฌ์ด์˜ ์ด๊ฒฉ๊ฑฐ๋ฆฌ๋ฅผ ํฌํ•จํ•œ ๋งค๊ฐœ ๋ณ€์ˆ˜ ํ•ด์„ ๊ฒฐ๊ณผ๋ฅผ ๋ถ„์„ํ•˜์˜€๋‹ค(Fig. 4). ์šฐ์„ , Fig. 4(a)๋Š” ๋‘ ์ „๊ทน์˜ ์ค‘๊ฐ„ ์ง€์ (u=0.5L)์— ์ง€ํ•˜๋งค์„ค๋ฌผ(์ง๊ฒฝ D=0.6 m)์ด ๋งค์„ค๋œ ๊ฒฝ์šฐ์— ๋งค์„ค ๊นŠ์ด d์— ๋”ฐ๋ฅธ ์ „๊ธฐ์ €ํ•ญ ๋ณ€ํ™”๋ฅผ ๋ณด์—ฌ์ค€๋‹ค. ๋ชจ๋“  ๊ฒฝ์šฐ์— ๋งค์„ค ๊นŠ์ด d๊ฐ€ ๊นŠ์–ด์งˆ์ˆ˜๋ก, ์ „๊ทน ์‚ฌ์ด ๊ฐ„๊ฒฉ์— ์ƒ๊ด€์—†์ด ์ „๊ธฐ์ €ํ•ญ์€ ๊ฐ์†Œํ•˜์˜€๋‹ค. ์ „๊ธฐ์ €ํ•ญ ๊ฐ์†Œ๋Ÿ‰์€ ๋งค์„ค๋ฌผ ๊นŠ์ด d=1 m๊นŒ์ง€ ๊ธ‰๊ฒฉํ•˜๊ฒŒ ๊ฐ์†Œํ•˜์˜€์ง€๋งŒ, ๊ทธ ์ดํ›„๋ถ€ํ„ฐ๋Š” ์ง€ํ•˜๋งค์„ค๋ฌผ์ด ์—†๋Š” ์กฐ๊ฑด์—์„œ ํ•ด์„ํ•œ ๊ฒฝ์šฐ์—์„œ ์–ป์–ด์ง€๋Š” ์ „๊ธฐ์ €ํ•ญ๊ฐ’์— ์ ์ฐจ ์ˆ˜๋ ดํ•˜์˜€๋‹ค. ์ „๊ธฐ์ €ํ•ญ๊ฐ’์ด ์ˆ˜๋ ดํ•˜๋Š” ์ง€ํ•˜๋งค์„ค๋ฌผ ๊นŠ์ด๋Š” ์ „๊ทน ์‚ฌ์ด ๊ฐ„๊ฒฉ์ด ๊ฐ€๊นŒ์šธ์ˆ˜๋ก ๋” ๊นŠ์€ ๋งค์„ค๋ฌผ ๊นŠ์ด์—์„œ ์ˆ˜๋ ดํ•˜์˜€๋‹ค(์ „๊ทน ์‚ฌ์ด ๊ฐ„๊ฒฉ L=0.9 m์ธ ๊ฒฝ์šฐ์—๋Š” ๋งค์„ค ๊นŠ์ด d=3.5 m ์ˆ˜๋ ดํ•˜์˜€์ง€๋งŒ, L=2 m์ผ ๋•Œ์—๋Š” ์ƒ๋Œ€์ ์œผ๋กœ ์–•์€ ๊นŠ์ด d=1 m์—์„œ ์ˆ˜๋ ดํ•จ). ์ด๋Š” ๋” ๊นŠ์€ ๊นŠ์ด๊นŒ์ง€ ์ง€ํ•˜๋งค์„ค๋ฌผ์„ ํƒ์ง€ํ•˜๊ธฐ ์œ„ํ•ด์„œ๋Š” ์ „๊ทน ์‚ฌ์ด ๊ฐ„๊ฒฉ์„ ์ตœ์†Œํ™”์‹œ์ผœ์•ผ ํ•จ์„ ์˜๋ฏธํ•œ๋‹ค. ๋˜ํ•œ, ๋™์ผํ•œ ์ง€ํ•˜๋งค์„ค๋ฌผ ๊นŠ์ด์—์„œ๋Š” ์ „๊ทน ์‚ฌ์ด ๊ฑฐ๋ฆฌ๊ฐ€ ์ฆ๊ฐ€ํ• ์ˆ˜๋ก ์ „๊ธฐ์ €ํ•ญ๊ฐ’์ด ์ฆ๊ฐ€ํ•˜์˜€๋‹ค.

Fig. 4(b)๋Š” ์ง€ํ•˜๋งค์„ค๋ฌผ ์ง๊ฒฝ(๋งค์„ค ๊นŠ์ด d=0.5 m ๊ทธ๋ฆฌ๊ณ  ์ด๊ฒฉ๊ฑฐ๋ฆฌ u=0.5 L)์— ๋”ฐ๋ฅธ ์ „๊ธฐ์ €ํ•ญ ๋ณ€ํ™”๋ฅผ ๋ณด์—ฌ์ค€๋‹ค. ๋ชจ๋“  ๊ฒฝ์šฐ์— ์ „๊ทน ์‚ฌ์ด ๊ฑฐ๋ฆฌ L์ด ์ฆ๊ฐ€ํ•จ์— ๋”ฐ๋ผ์„œ ์ „๊ธฐ์ €ํ•ญ๊ฐ’์ด ์ฆ๊ฐ€ํ•˜์˜€๊ณ , ์ง€ํ•˜๋งค์„ค๋ฌผ์ด ๋งค์„ค๋œ ๊ฒฝ์šฐ์— ์–ป์–ด์ง€๋Š” ์ „๊ธฐ์ €ํ•ญ๊ฐ’์€ ์ง€ํ•˜๋งค์„ค๋ฌผ์ด ์—†๋Š” ์กฐ๊ฑด์—์„œ ํ•ด์„ํ•œ ๊ฒฝ์šฐ๋ณด๋‹ค ์ „๊ธฐ์ €ํ•ญ๊ฐ’์ด ๋ชจ๋“  ๊ฒฝ์šฐ์—์„œ ํฌ๊ฒŒ ๋‚˜ํƒ€๋‚ฌ๋‹ค. ์ง€ํ•˜๋งค์„ค๋ฌผ ์ง๊ฒฝ์ด ํด์ˆ˜๋ก ์ „๊ธฐ์ €ํ•ญ๊ฐ’์ด ํฌ๊ฒŒ ๋‚˜ํƒ€๋‚ฌ์ง€๋งŒ, ๊ทธ ์ฐจ์ด๋Š” ์ „๊ทน ์‚ฌ์ด ๊ฐ„๊ฒฉ์ด ์ฆ๊ฐ€ํ•จ์— ๋”ฐ๋ผ์„œ ์ ์ฐจ ๊ฐ์†Œํ•˜์˜€๋‹ค. ๋”ฐ๋ผ์„œ, ์ถฉ๋ถ„ํ•œ ์ „๊ทน ์‚ฌ์ด ๊ฐ„๊ฒฉ์€ ์ง€๋ฐ˜์˜ ํƒ์‚ฌ ์˜์—ญ์„ ์ฆ๊ฐ€์‹œํ‚ค์ง€๋งŒ, ํƒ์‚ฌ ๋ถ„ํ•ด๋Šฅ์„ ๊ฐ์†Œ์‹œํ‚ค๋ฏ€๋กœ ์ง€ํ•˜๋งค์„ค๋ฌผ ์ง๊ฒฝ ๋˜๋Š” ํฌ๊ธฐ๋ฅผ ํƒ์ง€ํ•˜๋Š”๋ฐ ๋ฐฉํ•ด๊ฐ€ ๋œ๋‹ค.

Fig. 4(c)๋Š” ํ•œ์ชฝ ์ „๊ทน์œผ๋กœ๋ถ€ํ„ฐ ์ง€ํ•˜๋งค์„ค๋ฌผ(๋งค์„ค ๊นŠ์ด d=0.5 m ๊ทธ๋ฆฌ๊ณ  ์ง๊ฒฝ D=0.6 m)์ด ๋–จ์–ด์ง„ ์ด๊ฒฉ๊ฑฐ๋ฆฌ u์— ๋”ฐ๋ฅธ ์ „๊ธฐ์ €ํ•ญ ๋ณ€ํ™”๋ฅผ ๋ณด์—ฌ์ค€๋‹ค. ์ง€ํ•˜๋งค์„ค๋ฌผ์ด ๋‘ ์ „๊ทน์˜ ์ค‘๊ฐ„ ์ง€์ (u=0.5 L)์— ๋งค์„ค๋˜์—ˆ์„ ๋•Œ ๊ฐ€์žฅ ๋‚ฎ์€ ์ „๊ธฐ์ €ํ•ญ๊ฐ’์„ ๋ณด์˜€์œผ๋ฉฐ, ์ง€ํ•˜๋งค์„ค๋ฌผ์ด ์—†๋Š” ์กฐ๊ฑด์—์„œ ์–ป์€ ์ „๊ธฐ์ €ํ•ญ๊ฐ’๋ณด๋‹ค ๋ชจ๋“  ๊ฒฝ์šฐ์—์„œ ํฌ๊ฒŒ ๋‚˜ํƒ€๋‚ฌ๋‹ค. ๋˜ํ•œ, ์ง€ํ•˜๋งค์„ค๋ฌผ์ด ์ „๊ทน์— ๊ฐ€๊น๊ฒŒ ๋งค์„ค๋˜์–ด ์žˆ์„์ˆ˜๋ก ์ „๊ธฐ์ €ํ•ญ๊ฐ’์€ ์ฆ๊ฐ€ํ•˜์˜€์œผ๋ฉฐ, ์ง€ํ•˜๋งค์„ค๋ฌผ์ด ๋‘ ์ „๊ทน์˜ ์ค‘๊ฐ„ ์ง€์ (u=0.5 L)์— ๋งค์„ค๋˜์—ˆ์„ ๋•Œ๋ฅผ ์ค‘์‹ฌ์œผ๋กœ ์ „๊ธฐ์ €ํ•ญ๊ฐ’์€ ๋Œ€์นญ์„ ๋ณด์˜€๋‹ค. ๊ทธ๋ฆฌ๊ณ  ๋™์ผํ•œ ์ด๊ฒฉ๊ฑฐ๋ฆฌ u์—์„œ ์ „๊ทน ์‚ฌ์ด ๊ฐ„๊ฒฉ L์ด ํด์ˆ˜๋ก ์ „๊ธฐ์ €ํ•ญ๊ฐ’์ด ์ฆ๊ฐ€ํ•˜์˜€๋‹ค.

์ถ”๊ฐ€์ ์œผ๋กœ, ๋‘ ์ „๊ทน ์‚ฌ์ด์—์„œ ๋ฐœ์ƒํ•˜๋Š” ์ „์•• ๊ฐ•ํ•˜๋กœ ์ธํ•ด์„œ ํ˜•์„ฑ๋˜๋Š” ๋“ฑ์ „์œ„๋ฉด๊ณผ ํ๋ฅด๋Š” ์ „๋ฅ˜์˜ ์„ธ๊ธฐ๋ฅผ ์ •๋Ÿ‰์ ์œผ๋กœ ๋ถ„์„ํ•˜๊ธฐ ์œ„ํ•ด์„œ, ์ „์œ„์™€ ์ „๋ฅ˜๋ฐ€๋„ ๋ถ„ํฌ๋ฅผ ์„ ํƒ๋œ ํ•ด์„ ์ผ€์ด์Šค๋“ค์— ๋Œ€ํ•ด์„œ ๋„์‹œํ•˜์˜€๋‹ค. ์ผ๋ฐ˜์ ์œผ๋กœ, ๊ฑฐ๋ฆฌ์— ๋”ฐ๋ฅธ ์ „์•• ๋ณ€ํ™”๋ฅผ ๋‚˜ํƒ€๋‚ด๋Š” ์ „๊ธฐ์žฅ๊ณผ ์ „๊ธฐ์ „๋„๋„์— ์˜ํ•ด์„œ ๊ฒฐ์ •๋˜๋Š” ์ „๋ฅ˜๋ฐ€๋„ J(=ฯƒยทdV/dz)๋Š” ์ผ์ •ํ•œ ์ „๊ธฐ์ „๋„๋„๋กœ ํ˜•์„ฑ๋œ ๊ท ์งˆํ•œ ์ง€๋ฐ˜ ์กฐ๊ฑด์—์„œ ๊ฑฐ๋ฆฌ์— ๋”ฐ๋ฅธ ์ „์œ„์˜ ๋ณ€ํ™”๋Ÿ‰์— ๋น„๋ก€ํ•˜๊ฒŒ ๋œ๋‹ค.

Fig. 5๋Š” ์„ ํƒ๋œ ์ง€ํ•˜๋งค์„ค๋ฌผ์˜ ๊นŠ์ด(d=0.25 m ๊ทธ๋ฆฌ๊ณ  d=1.0 m)์—์„œ ์ „์œ„ ๋ถ„ํฌ์™€ ์ „๋ฅ˜๋ฐ€๋„ ๋ถ„ํฌ๋ฅผ ๊ฐ๊ฐ ๋ณด์—ฌ์ค€๋‹ค. Fig. 5(a)์—์„œ ๋ณด์ด๋Š” ๋ฐ”์™€ ๊ฐ™์ด, ์–•์€ ๊นŠ์ด(d=0.25 m)์— ๋งค์„ค๋œ ์ง€ํ•˜๋งค์„ค๋ฌผ์€ ๋‘ ์ „๊ทน ์‚ฌ์ด์˜ ์ „๋ฅ˜ ํ๋ฆ„์„ ๋ฐฉํ•ดํ•˜๋ฏ€๋กœ, ์ง€ํ•˜๋งค์„ค๋ฌผ ์ƒ๋ถ€์—์„œ ์ „๋ฅ˜๊ฐ€ ํ๋ฅด๋Š” ๋ฐฉํ–ฅ์œผ๋กœ ์ „์••์ด 0.53 V์—์„œ 0.47 V๊นŒ์ง€ ๊ธ‰๊ฒฉํ•œ ์ „์•• ๊ฐ•ํ•˜๋ฅผ ๋ณด์˜€์ง€๋งŒ, ๊นŠ์€ ๊นŠ์ด(d=1 m)์— ์ง€ํ•˜๋งค์„ค๋ฌผ์€ ๋งค์„ค๋ฌผ ์ƒ๋ถ€์—์„œ ์•ฝ 0.5 V ์ „์••๊ณผ ์™„๋งŒํ•œ ์ „์•• ๊ฐ•ํ•˜๋ฅผ ๋ณด์—ฌ์ฃผ๊ณ , ์ „์œ„ ๋ถ„ํฌ๋Š” ์ง€ํ•˜๋งค์„ค๋ฌผ์ด ์—†๋Š” ๊ฒฝ์šฐ์™€ ๋น„์Šทํ•˜๊ฒŒ ํ˜•์„ฑ๋˜์—ˆ๋‹ค. ๋˜ํ•œ, Fig. 5(b)์—์„œ ๋ณด์ด๋Š” ๋ฐ”์™€ ๊ฐ™์ด, ์–•์€ ๊นŠ์ด์— ๋งค์„ค๋œ ์ง€ํ•˜๋งค์„ค๋ฌผ ์ฃผ๋ณ€์—์„œ ํ˜•์„ฑ๋œ ์ „๋ฅ˜๋ฐ€๋„(d=0.25 m์ผ ๋•Œ, J=2.3ร—10-4 A/m2)๋Š” ๊นŠ๊ฒŒ ๋งค์„ค๋œ ์ง€ํ•˜๋งค์„ค๋ฌผ(d=1 m์ผ ๋•Œ, J=1ร—10-4 A/m2)๋ณด๋‹ค ๋™์ผํ•œ ๊นŠ์ด์—์„œ ์•ฝ 2๋ฐฐ ๋†’๊ฒŒ ํ˜•์„ฑ๋˜์—ˆ์œผ๋ฉฐ, ์ด๋Š” ์ „๊ธฐ์žฅ ์„ธ๊ธฐ๊ฐ€ ๊ฐ์†Œ๋˜์—ˆ๊ธฐ ๋•Œ๋ฌธ์ด๋‹ค.

Fig. 6๋Š” ์„ ํƒ๋œ ์ง€ํ•˜๋งค์„ค๋ฌผ ์ง๊ฒฝ(D=0.3 m ๊ทธ๋ฆฌ๊ณ  D=0.9 m)์—์„œ ์ „์œ„ ๋ถ„ํฌ์™€ ์ „๋ฅ˜๋ฐ€๋„ ๋ถ„ํฌ๋ฅผ ๊ฐ๊ฐ ๋ณด์—ฌ์ค€๋‹ค. Fig. 6(a)์— ๋ณด์ด๋Š” ๋ฐ”์™€ ๊ฐ™์ด, ์ž‘์€ ์ง๊ฒฝ์˜ ์ง€ํ•˜๋งค์„ค๋ฌผ ์ƒ๋ถ€์—์„œ ์•ฝ 0.5 V ์ „์••๊ณผ ์™„๋งŒํ•œ ์ „์•• ๊ฐ•ํ•˜๋ฅผ ๋ณด์—ฌ์ฃผ๊ณ , ๋“ฑ์ „์œ„๋ฉด์€ ์ง€ํ•˜๋งค์„ค๋ฌผ์ด ์—†๋Š” ๊ฒฝ์šฐ์™€ ๋น„์Šทํ•˜๊ฒŒ ํ˜•์„ฑ๋˜์—ˆ๋‹ค. ํ•˜์ง€๋งŒ, ํฐ ์ง๊ฒฝ์˜ ์ง€ํ•˜๋งค์„ค๋ฌผ ์ƒ๋ถ€(D=0.9 m)๋Š” ์ „๋ฅ˜๊ฐ€ ํ๋ฅด๋Š” ๋ฐฉํ–ฅ์œผ๋กœ ์ „์••์ด 0.53 V์—์„œ 0.47 V ๊นŒ์ง€ ๊ธ‰๊ฒฉํ•˜๊ฒŒ ์ „์œ„๊ฐ€ ๊ฐ์†Œํ•˜์˜€๋‹ค. ๋˜ํ•œ, Fig. 6(b)์—์„œ ๋ณด์ด๋Š” ๋ฐ”์™€ ๊ฐ™์ด, ํฌ๊ธฐ๊ฐ€ ์ž‘์€ ๋งค์„ค๋ฌผ ์ฃผ๋ณ€์—์„œ ํ˜•์„ฑ๋œ ์ „๋ฅ˜๋ฐ€๋„(D=0.3 m ์ผ ๋•Œ, J=5ร—10-6 A/m2)๋Š” ์ƒ๋Œ€์ ์œผ๋กœ ํฌ๊ธฐ๊ฐ€ ํฐ ๋งค์„ค๋ฌผ(D=0.9 m ์ผ ๋•Œ, J=1.5ร—10-5 A/m2)๋ณด๋‹ค ๋™์ผํ•œ ๊นŠ์ด์—์„œ ๋‚ฎ์€ ์ „๋ฅ˜๋ฐ€๋„๊ฐ€ ํ˜•์„ฑ๋œ ๊ฒƒ์„ ๋ณด์—ฌ์ค€๋‹ค.

Fig. 7์€ ์„ ํƒ๋œ ์ง€ํ•˜๋งค์„ค๋ฌผ ์ด๊ฒฉ๊ฑฐ๋ฆฌ(u=0.45 m ๊ทธ๋ฆฌ๊ณ  u=0.9 m)์—์„œ ์ „์œ„ ๋ถ„ํฌ์™€ ์ „๋ฅ˜๋ฐ€๋„ ๋ถ„ํฌ๋ฅผ ๊ฐ๊ฐ ๋ณด์—ฌ์ค€๋‹ค. ํ„ฐ๋ฏธ๋„ ์ „๊ทน์— ์ƒ๋Œ€์ ์œผ๋กœ ๊ฐ€๊น๊ฒŒ ๋งค์„ค๋œ ์ง€ํ•˜๋งค์„ค๋ฌผ์€ ๋งค์„ค๋ฌผ ์ฃผ๋ณ€์—์„œ ์ „๋ฅ˜๊ฐ€ ํ๋ฅด๋Š” ๋ฐฉํ–ฅ์œผ๋กœ ์ „์••์ด 0.54 V์—์„œ 0.5 V๊นŒ์ง€ ๋‹ค์†Œ ๊ธ‰๊ฒฉํ•˜๊ฒŒ ์ „์œ„๊ฐ€ ๊ฐ์†Œํ•˜์˜€์ง€๋งŒ, ์ด๊ฒฉ๊ฑฐ๋ฆฌ๊ฐ€ ์ฆ๊ฐ€ํ• ์ˆ˜๋ก ์ง€ํ•˜๋งค์„ค๋ฌผ ์ฃผ๋ณ€์—์„œ ์•ฝ 0.5 V ์ „์••๊ณผ ์™„๋งŒํ•œ ์ „์•• ๊ฐ•ํ•˜๋ฅผ ๋ณด์—ฌ์ฃผ๊ณ  ์žˆ๋‹ค(Fig. 7(a)). ์ „๋ฅ˜๋ฐ€๋„๋Š” ์ด๊ฒฉ๊ฑฐ๋ฆฌ์— ์ƒ๊ด€์—†์ด ์ง€ํ•˜๋งค์„ค๋ฌผ ์ธก๋ถ€์—์„œ ์ง‘์ค‘ํ•˜์˜€๋‹ค. ํ•˜์ง€๋งŒ, ๊ฐ€๊นŒ์šด ์ด๊ฒฉ๊ฑฐ๋ฆฌ์—์„œ๋Š” 6๋ฐฐ ์ •๋„์˜ ๋” ํฐ ์ „๋ฅ˜๋ฐ€๋„๋ฅผ ๋ณด์˜€๋‹ค(u=0.45 m์ผ ๋•Œ, J=9ร—10-5 A/m2; u=0.9 m์ผ ๋•Œ, J=1.5ร—10-5 A/m2). ์ „์œ„์™€ ์ „๋ฅ˜๋ฐ€๋„์˜ ๋ถ„ํฌ๋Š” ๋น„๋Œ€์นญ ํ˜•์ƒ์„ ๋ณด์ด๊ณ , ํŠนํžˆ ์ „๋ฅ˜๋ฐ€๋„๋Š” ์ „๊ทน์—์„œ๋ถ€ํ„ฐ ์ง€ํ•˜๋งค์„ค๋ฌผ๊นŒ์ง€ ๋ถˆ๊ทœ์น™ํ•œ ๋ถ„ํฌ๋ฅผ ๋ณด์˜€๋‹ค.

Fig. 4. Variation in Electrical Resistance with Geometrical Conditions of Underground Structure: (a) Burial Depth, (b) Diameter, (c) Distance from the Terminal Electrode. The G and T Symbols Indicate Ground Electrode and Terminal Electrode, Respectively
../../Resources/KSCE/Ksce.2024.44.1.0049/fig4.png
Fig. 5. Effect of Underground Structure Burial Depth on the Voltage Drop and Current Flow: Distribution of (a) Electric Potential and (b) Current Density. Cases are Distance Electrodes L=1.3 m, Distance from Terminal Electrode u=0.5 L, and Underground Structure Diameter D=0.6 m
../../Resources/KSCE/Ksce.2024.44.1.0049/fig5.png
Fig. 6. Effect of Underground Structure Diameter on the Voltage Drop and Current Flow: Distribution of (a) Electric Potential and (b) Current Density. Cases are Burial Depth d=0.5 m, Distance Electrodes L=2 m, and Distance from Terminal Structure u=0.5 L
../../Resources/KSCE/Ksce.2024.44.1.0049/fig6.png
Fig. 7. Effect of Distance from the Terminal Electrode on the Voltage Drop and Current Flow: Distribution of (a) Electric Potential and (b) Current Density. Cases are Burial Depth d=0.5 m, Distance Electrodes L=3 m, and Underground Structure Diameter D=0.6 m
../../Resources/KSCE/Ksce.2024.44.1.0049/fig7.png

5. ๊ฒฐ ๋ก 

๋ณธ ์—ฐ๊ตฌ์—์„œ๋Š” ์ƒ์šฉ ์œ ํ•œ ์š”์†Œ ํ”„๋กœ๊ทธ๋žจ์„ ์ด์šฉํ•˜์—ฌ ์ •์ƒ ์ƒํƒœ์—์„œ ์ „๊ธฐ์ €ํ•ญ ์ˆ˜์น˜ ํ•ด์„ ๋ชจ๋“ˆ์„ ๊ฐœ๋ฐœํ•˜์˜€๊ณ , ์ „๊ทน๊ณผ ์ง€ํ•˜๋งค์„ค๋ฌผ์˜ ๊ธฐํ•˜ํ•™์  ๋งค๊ฐœ ๋ณ€์ˆ˜ ํ•ด์„์— ๋”ฐ๋ฅธ ์ „๊ธฐ์ €ํ•ญ ๋ณ€ํ™”๋ฅผ ์ •๋Ÿ‰์ ์œผ๋กœ ๋ถ„์„ํ•˜์˜€๋‹ค. ์ถ”๊ฐ€์ ์œผ๋กœ, ์ „๊ทน๊ณผ ์ง€ํ•˜๋งค์„ค๋ฌผ ์ฃผ๋ณ€์— ํ˜•์„ฑ๋œ ์ „์œ„ ๋ถ„ํฌ์™€ ์ „๋ฅ˜๋ฐ€๋„ ๋ถ„ํฌ๋ฅผ ๋ถ„์„ํ•˜์—ฌ, ํ„ฐ๋ฏธ๋„ ์ „๊ทน ์ฃผ๋ณ€์—์„œ ์ธก์ •๋œ ์ „๊ธฐ์ €ํ•ญ๊ฐ’์„ ๊ณ ์ฐฐํ•˜์—ฌ ์–ป์–ด์ง„ ๊ฒฐ๋ก ์€ ๋‹ค์Œ๊ณผ ๊ฐ™๋‹ค.

(1) ์ „๊ทน๊ณผ ์ง€ํ•˜๋งค์„ค๋ฌผ ๊ทธ๋ฆฌ๊ณ  ์ด๋“ค์˜ ์ฃผ๋ณ€ ๋ฉ”์‰ฌ๋ฅผ ํฌํ•จํ•œ ๋„๋ฉ”์ธ์˜ ๋ฉ”์‰ฌ ๋ชจ๋ธ๋ง์€ Mapped์™€ Swept ๊ธฐ๋Šฅ์„ ์ด์šฉํ•˜์—ฌ ํšจ์œจ์ ์œผ๋กœ ์ผ๊ด€๋œ ๋ฉ”์‰ฌ๋ฅผ ํ˜•์„ฑํ•˜์˜€๋‹ค. ๋ณธ ์—ฐ๊ตฌ์—์„œ ์ œ์•ˆํ•œ ์ •๋Ÿ‰ํ™”๋œ ๋ฉ”์‰ฌ๋Š” ์ด๋ก ์‹๊ณผ ์ˆ˜์น˜ ํ•ด์„์„ ํ†ตํ•ด ์–ป์€ ์ „๊ธฐ์ €ํ•ญ๊ฐ’์˜ ์˜ค์ฐจ๋ฅผ ์ตœ์†Œํ™”ํ•˜์˜€์œผ๋ฉฐ, ๋ชจ๋“  ๊ฑฐ๋ฆฌ์—์„œ ์˜ค์ฐจ๋Š” 0.005 ๋ฏธ๋งŒ์œผ๋กœ ์ƒ๋‹นํžˆ ์ ์€ ๊ฐ’์ด ๋‚˜ํƒ€๋‚ฌ๋‹ค. ์ด์™€ ๊ฐ™์€ ๊ฒฐ๊ณผ๋“ค์€ ๊ฐœ๋ฐœ๋œ ์ „๊ธฐ์ €ํ•ญ ์ˆ˜์น˜ ํ•ด์„ ๋ชจ๋“ˆ์˜ ๋†’์€ ์‹ ๋ขฐ์„ฑ์„ ๋ณด์—ฌ์ค€๋‹ค.

(2) ์ „๊ธฐ์ €ํ•ญ์€ ์ „๊ทน ์‚ฌ์ด ๊ฐ„๊ฒฉ์— ์ƒ๊ด€์—†์ด ๋งค์„ค ๊นŠ์ด๊ฐ€ ๊นŠ์–ด์งˆ์ˆ˜๋ก ๊ฐ์†Œํ•˜์˜€์ง€๋งŒ, ์ผ์ • ๊นŠ์ด ์ดํ›„๋ถ€ํ„ฐ๋Š” ์ง€ํ•˜๋งค์„ค๋ฌผ์ด ์—†๋Š” ์กฐ๊ฑด์˜ ์ €ํ•ญ๊ฐ’์— ์ ์ฐจ ์ˆ˜๋ ดํ•˜์˜€๋‹ค. ๊ทธ๋ฆฌ๊ณ  ์ „๊ธฐ์ €ํ•ญ๊ฐ’์ด ์ˆ˜๋ ดํ•˜๋Š” ๋งค์„ค๋ฌผ์˜ ๊นŠ์ด๋Š” ์ „๊ทน ์‚ฌ์ด ๊ฐ„๊ฒฉ์ด ๊ฐ€๊นŒ์šธ์ˆ˜๋ก ๋” ๊นŠ์€ ๋งค์„ค ๊นŠ์ด์—์„œ ์ˆ˜๋ ดํ•˜์˜€๋‹ค. ์ด๋Š” ๋” ๊นŠ์€ ๊นŠ์ด๊นŒ์ง€ ์ง€ํ•˜๋งค์„ค๋ฌผ์„ ํƒ์ง€ํ•˜๊ธฐ ์œ„ํ•ด์„œ๋Š” ์ „๊ทน ์‚ฌ์ด ๊ฐ„๊ฒฉ์„ ์ตœ์†Œํ™”์‹œ์ผœ์•ผ ํ•จ์„ ์˜๋ฏธํ•œ๋‹ค.

(3) ์ง€ํ•˜๋งค์„ค๋ฌผ ์ง๊ฒฝ์ด ํด์ˆ˜๋ก ์ „๊ธฐ์ €ํ•ญ๊ฐ’์ด ํฌ๊ฒŒ ๋‚˜ํƒ€๋‚ฌ์ง€๋งŒ, ์ „๊ทน ์‚ฌ์ด ๊ฐ„๊ฒฉ์ด ์ฆ๊ฐ€ํ•จ์— ๋”ฐ๋ผ์„œ ๋งค์„ค๋ฌผ์˜ ํฌ๊ธฐ์— ๋”ฐ๋ฅธ ์ €ํ•ญ๊ฐ’ ์ฐจ์ด๋Š” ๊ฐ์†Œํ•˜์˜€๋‹ค. ๋”ฐ๋ผ์„œ, ์ถฉ๋ถ„ํ•œ ์ „๊ทน ์‚ฌ์ด ๊ฐ„๊ฒฉ์€ ์ง€๋ฐ˜์˜ ํƒ์‚ฌ ์˜์—ญ์„ ์ฆ๊ฐ€์‹œํ‚ค์ง€๋งŒ, ํƒ์‚ฌ ๋ถ„ํ•ด๋Šฅ์„ ๊ฐ์†Œ์‹œํ‚ค๋ฏ€๋กœ ์ง€ํ•˜๋งค์„ค๋ฌผ ์ง๊ฒฝ ๋˜๋Š” ํฌ๊ธฐ๋ฅผ ํƒ์ง€ํ•˜๋Š”๋ฐ ๋ฐฉํ•ด๋ฅผ ์ผ์œผํ‚จ๋‹ค.

(4) ์ง€ํ•˜๋งค์„ค๋ฌผ์ด ์ „๊ทน์— ๊ฐ€๊น๊ฒŒ ์œ„์น˜ํ• ์ˆ˜๋ก ์ €ํ•ญ๊ฐ’์€ ์ฆ๊ฐ€ํ•˜์˜€์œผ๋ฉฐ, ๋งค์„ค๋ฌผ์ด ๋‘ ์ „๊ทน ์‚ฌ์ด ์ค‘์•™์— ์œ„์น˜ํ•œ ๊ฒฝ์šฐ์—๋Š” ์ €ํ•ญ๊ฐ’์ด ๋‹ค์†Œ ๊ฐ์†Œํ•˜์˜€๋‹ค. ์ „๊ธฐ์ €ํ•ญ์€ ์ „๊ทน ๊ฐ„ ์ค‘์‹ฌ์„ ๊ธฐ์ค€์œผ๋กœ ๋Œ€์นญ์ ์œผ๋กœ ๋‚˜ํƒ€๋‚ฌ๋‹ค. ํ•˜์ง€๋งŒ, ์ „๊ทน ์‚ฌ์ด ๊ฑฐ๋ฆฌ๊ฐ€ ์งง์„์ˆ˜๋ก ์ „๊ทน๊ณผ์˜ ์ด๊ฒฉ๊ฑฐ๋ฆฌ์— ์ƒ๊ด€์—†์ด ์ €ํ•ญ๊ฐ’์€ ๊ฑฐ์˜ ์ผ์ •ํ•˜๊ฒŒ ๋‚˜ํƒ€๋‚ฌ๋‹ค.

(5) ์ €ํ•ญ์ด ํฐ ์ง€ํ•˜๋งค์„ค๋ฌผ์˜ ์กด์žฌ๋Š” ์ „๊ทน ์‚ฌ์ด์˜ ์ „๋ฅ˜ ํ๋ฆ„์„ ๋ฐฉํ•ดํ•˜๋ฉฐ, ๋งค์„ค๋ฌผ์ด ์–•์€ ๊นŠ์ด์— ์œ„์น˜ํ•ด ์žˆ๊ณ , ์ง๊ฒฝ์ด ํฌ๊ณ , ๊ทธ๋ฆฌ๊ณ  ์ „๊ทน๊ณผ์˜ ์ด๊ฒฉ๊ฑฐ๋ฆฌ๊ฐ€ ์งง์„์ˆ˜๋ก ๋งค์„ค๋ฌผ ์ฃผ๋ณ€์—์„œ ๊ธ‰๊ฒฉํ•œ ์ „์•• ๊ฐ•ํ•˜์™€ ํ•จ๊ป˜ ๋†’์€ ์ „๋ฅ˜๋ฐ€๋„ ๋ถ„ํฌ๊ฐ€ ํ˜•์„ฑ๋˜์—ˆ๋‹ค.

์ถ”ํ›„ ์—ฐ๊ตฌ์—์„œ๋Š” (a) ์ง€๋ฐ˜ ์ „๊ธฐ๋น„์ €ํ•ญ์˜ ๊ณต๊ฐ„์  ๋ถ„ํฌ์— ๋”ฐ๋ฅธ ์ „๊ธฐ์ €ํ•ญ ์ธก์ • ๋ณ€ํ™”์— ๋Œ€ํ•œ ์ถ”๊ณ„๋ก ์  ์ˆ˜์น˜ ํ•ด์„ ์—ฐ๊ตฌ์™€ (b) ๋” ๋งŽ์€ ์ „๊ทน ๊ฐœ์ˆ˜์™€ ๋‹ค์–‘ํ•œ ์ง€ํ•˜๋งค์„ค๋ฌผ ์กฐ๊ฑด(์ง€ํ•˜๋งค์„ค๋ฌผ๊ณผ ์ „๊ทน ๋ฐฉํ–ฅ, ์ง€ํ•˜๋งค์„ค๋ฌผ ํฌ๊ธฐ์™€ ํ˜•์ƒ)์— ๋”ฐ๋ฅธ ์ „๊ธฐ์ €ํ•ญ ๋ณ€ํ™” ๋ถ„์„๊ณผ (c) ์–‘์‚ฐ๋œ ์ „๊ธฐ์ €ํ•ญ ๋ฐ์ดํ„ฐ ์ด์šฉํ•œ ๊ณ ๊ธ‰ํ™”๋œ ๋”ฅ๋Ÿฌ๋‹ ์•Œ๊ณ ๋ฆฌ์ฆ˜์„ ๊ฐœ๋ฐœํ•˜์—ฌ ํ˜„์žฅ ์ ์šฉ์„ ํ•  ์˜ˆ์ •์ด๋‹ค.

Acknowledgements

This research work was funded by Korea Electric Power Corporation, grant number R21SA02. This paper has been written by modifying and supplementing the KSCE 2023 CONVENTION paper.

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