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

  1. ์šฉ์ธ์‹œ์ฒญ ๋„์‹œ๊ฐœ๋ฐœ๊ณผ ์‹ค๋ฌด๊ด€ (Yongin City Hall)
  2. ํ•œ๊ตญ๊ฑด์„ค๊ธฐ์ˆ ์—ฐ๊ตฌ์› ๋ฐ•์‚ฌํ›„์—ฐ๊ตฌ์› (Korea Institute of Civil Engineering and Building Technology)
  3. ์—ฐ์„ธ๋Œ€ํ•™๊ต ํ† ๋ชฉํ™˜๊ฒฝ๊ณตํ•™๊ณผ ๊ต์ˆ˜ (Yonsei University)


๊ฐ•์ง€๋ณด, ์ˆํฌ๋ฆฌํŠธ, ํ•ฉ์„ฑ๋‹จ๋ฉด, ํ™”์ด๋ฒ„ ๋‹จ๋ฉด ์š”์†Œ, ์ง€๋ฐ˜ ๊ฐ•์„ฑ, ๊ทนํ•œํ•ด์„
Steel supports, Shotcrete, Composite cross-section, Fiber section element, Ground stiffness, Ultimate analysis

  • 1. ์„œ ๋ก 

  • 2. ๋น„์„ ํ˜• ์œ ํ•œ์š”์†Œ ํ•ด์„ ๋ชจ๋ธ

  •   2.1 ํ„ฐ๋„ ๊ตฌ์กฐ์ฒด

  •   2.1.1 ํ™”์ด๋ฒ„ ๋‹จ๋ฉด ์š”์†Œ

  •   2.1.2 ์ˆํฌ๋ฆฌํŠธ ๊ตฌ์„ฑ๋ฐฉ์ •์‹

  •   2.1.3 ๊ฐ•์žฌ ๊ตฌ์„ฑ๋ฐฉ์ •์‹

  •   2.2 ์ง€๋ฐ˜โ€“๊ตฌ์กฐ๋ฌผ ์ƒํ˜ธ์ž‘์šฉ

  • 3. ์ˆํฌ๋ฆฌํŠธ์˜ ์žฌ๋ฃŒ๋ชจ๋ธ๊ณผ ๋ฌผ์„ฑ ๊ฒฐ์ •

  •   3.1 ์ถ•๋ ฅ๊ณผ ํœจ ๋ชจ๋ฉ˜ํŠธ๋ฅผ ๋ฐ›๋Š” ์ˆํฌ๋ฆฌํŠธ ๋ถ€์žฌ์˜ ํ•˜์ค‘ ์‹คํ—˜

  •   3.2 ์—ญํ•ด์„์„ ํ†ตํ•œ ์ˆํฌ๋ฆฌํŠธ ์žฌ๋ฃŒ๋ฌผ์„ฑ ๊ฒฐ์ •

  • 4. ๊ฐ•์ง€๋ณด-์ˆํฌ๋ฆฌํŠธ ํ•ฉ์„ฑ๋ถ€์žฌ์˜ ๋น„์„ ํ˜• ํ•ฉ์„ฑ๊ฑฐ๋™ ๋ถ„์„

  •   4.1 ๊ฐ•์ง€๋ณด-์ˆํฌ๋ฆฌํŠธ ํ•ฉ์„ฑ๋ถ€์žฌ์˜ ํ•˜์ค‘-๋ณ€์œ„ ์‘๋‹ต ๋ฐ ๋‹จ๋ฉด๋ ฅ ๋ณ€ํ™”

  •   4.2 ๊ฐ• ์ง€๋ณด๋Ÿ‰ ์ฆ๊ฐ€์— ๋”ฐ๋ฅธ ํ•˜์ค‘์ง€์ง€์„ฑ๋Šฅ ๋ถ„์„

  •   4.3 ์ง€๋ฐ˜ ๊ฐ•์„ฑ์ด ํ„ฐ๋„ ๊ตฌ์กฐ๋ฌผ์˜ ์ตœ๋Œ€ ํ•˜์ค‘์ง€์ง€๋ ฅ์— ๋ฏธ์น˜๋Š” ์˜ํ–ฅ

  • 5. ๊ฒฐ ๋ก 

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1. ์„œ ๋ก 

New Austrian Tunnelling Method (NATM)์€ ์ง€๋ฐ˜ ๊ตด์ฐฉ ํ›„ ์ˆํฌ๋ฆฌํŠธ, ๋ฝ๋ณผํŠธ ๋“ฑ์˜ ์ง€๋ณด์žฌ๋ฅผ ์„ค์น˜ํ•˜์—ฌ ์ง€๋ฐ˜์˜ ์ง€์ง€๋ ฅ์„ ์ตœ๋Œ€๋กœ ํ™œ์šฉํ•˜๋Š” ํ„ฐ๋„ ์‹œ๊ณต๋ฐฉ๋ฒ•์œผ๋กœ, ์ˆํฌ๋ฆฌํŠธ์— ๊ฐ•์ง€๋ณด๋ฅผ ๋ณด๊ฐ•ํ•จ์œผ๋กœ์จ ์ˆํฌ๋ฆฌํŠธ์˜ ์ง€๋ณด์„ฑ๋Šฅ์„ ํ–ฅ์ƒ์‹œํ‚ค๊ณ  ๋ง‰์žฅ๋ฉด์˜ ์•ˆ์ „์„ฑ์„ ํ™•๋ณดํ•˜๊ฒŒ ๋œ๋‹ค. ์ง€๊ธˆ๊นŒ์ง€์˜ NATM ํ„ฐ๋„ ๊ตฌ์กฐ๋ฌผ ์„ค๊ณ„๋Š” ์ˆํฌ๋ฆฌํŠธ ๋“ฑ์˜ 1์ฐจ ์ง€๋ณด์žฌ๊ฐ€ ์ตœ์ข…์ ์œผ๋กœ ํ•˜์ค‘์„ ๋ฐ›์ง€ ๋ชปํ•˜๋Š” ๊ฒƒ์œผ๋กœ ๊ณ ๋ คํ•˜์—ฌ, ์ฝ˜ํฌ๋ฆฌํŠธ ๋ผ์ด๋‹ ์„ค๊ณ„์— ์ด๋“ค ์ง€๋ณด์žฌ์˜ ํ•˜์ค‘์ง€์ง€๋Šฅ๋ ฅ์„ ๋ฐ˜์˜ํ•˜์ง€ ์•Š๋Š”๋‹ค. ๊ทธ๋Ÿฌ๋‚˜ ์ตœ๊ทผ ํ„ฐ๋„ ๋ผ์ด๋‹์˜ ๊ฒฝ์ œ์ ์ธ ์„ค๊ณ„์— ๋Œ€ํ•œ ์ˆ˜์š”๊ฐ€ ๋†’์•„์ง€๋ฉด์„œ ํ„ฐ๋„ ๊ตฌ์กฐ๋ฌผ์—๋„ ์„ฑ๋Šฅ๊ธฐ๋ฐ˜์„ค๊ณ„(performance based design)๋ฅผ ๋„์ž…ํ•˜๋ ค๋Š” ์›€์ง์ž„์ด ์กด์žฌํ•˜๊ณ  ์žˆ๋‹ค(Hur et al., 2013). ์„ฑ๋Šฅ๊ธฐ๋ฐ˜์„ค๊ณ„๋Š” ํ„ฐ๋„ ๊ตฌ์กฐ๋ฌผ์˜ ๊ฒฝ์ œ์  ์„ค๊ณ„๋ฅผ ๊ฐ€๋Šฅํ•˜๊ฒŒ ํ•˜์ง€๋งŒ, ๊ตฌ์กฐ๋ฌผ์˜ ์ „์ฒด์ ์ธ ๋ณด์œ ๋Šฅ๋ ฅ(capacity)์„ ํ‰๊ฐ€ํ•ด์•ผ ํ•˜๊ธฐ ๋•Œ๋ฌธ์— ์žฌ๋ฃŒ ๋ฐ ๊ตฌ์กฐ์  ํŠน์„ฑ์„ ๊ณ ๋ คํ•œ ์ •๊ตํ•œ ํ•ด์„์„ ํ•„์š”๋กœ ํ•œ๋‹ค. ํ•œํŽธ, ๊ฒฝ์ œ์ ์ธ ํ„ฐ๋„ ๋ผ์ด๋‹์˜ ์„ค๊ณ„๋ฅผ ์‹คํ˜„ํ•˜๊ธฐ ์œ„ํ•ด 1์ฐจ ์ง€๋ณด์žฌ์— ์˜ํ•œ ํ•˜์ค‘์ง€์ง€์„ฑ๋Šฅ์„ ์ฝ˜ํฌ๋ฆฌํŠธ ๋ผ์ด๋‹ ์„ค๊ณ„์— ๋ฐ˜์˜ํ•˜๊ณ , ๋” ๋‚˜์•„๊ฐ€ Norwegian Method of Tunneling (NMT)์™€ ๊ฐ™์ด ๊ฐ•์žฌ๋กœ ๋ณด๊ฐ•๋œ 1์ฐจ ์ง€๋ณด์žฌ๋งŒ์œผ๋กœ ํ„ฐ๋„ ๋ผ์ด๋‹์„ ์„ค๊ณ„ํ•˜๋ ค๋Š” ์—ฐ๊ตฌ๋“ค์ด ์ง„ํ–‰๋˜๊ณ  ์žˆ๋‹ค(Lee et al., 2001; Shin et al., 2006; Jeon et al., 2011). NMT๋Š” ๊ฒฝ์•” ๋“ฑ์˜ ์–‘ํ˜ธํ•œ ์ง€๋ฐ˜์— ์ ์šฉํ•˜๋Š” ํ„ฐ๋„๊ณต๋ฒ•์œผ๋กœ ๋ฝ๋ณผํŠธ ๋ฐ ๊ฐ•๋ด‰ ๋‹ค๋ฐœ๊ณผ ๊ฐ•์„ฌ์œ ๋กœ ๋ณด๊ฐ•๋œ ์ˆํฌ๋ฆฌํŠธ๋ฅผ ์ตœ์ข… ์˜๊ตฌ ์ง€๋ณด์žฌ๋กœ ์‚ฌ์šฉํ•˜๊ธฐ ๋•Œ๋ฌธ์— ๊ฒฝ์ œ์„ฑ ์ œ๊ณ ๋ฟ๋งŒ ์•„๋‹ˆ๋ผ ์ง€๋ณด์žฌ์˜ ์‹œ๊ณต ๋ฐ ์œ ์ง€๊ด€๋ฆฌ๊ฐ€ ์šฉ์ดํ•˜๋‹ค(Grimstad et al., 2002). ํŠนํžˆ, ์ˆํฌ๋ฆฌํŠธ๋Š” ์‹ฌํ•œ ๋น„์„ ํ˜• ๊ฑฐ๋™์„ ๋ณด์ด๋ฏ€๋กœ, ์ด๋ฅผ ๊ณ ๋ คํ•ด ์˜๊ตฌ ์ง€๋ณด์žฌ๋กœ์„œ์˜ ์„ฑ๋Šฅ์„ ํ‰๊ฐ€ํ•˜๋Š” ๊ฒƒ์ด ์š”๊ตฌ๋œ๋‹ค. ์–ด๋– ํ•œ ์„ค๊ณ„๋ฒ•์ด ๋” ์ ์ ˆํ•œ๊ฐ€์— ๋Œ€ํ•œ ๋…ผ์˜๊ฐ€ ํ•„์š”ํ•˜๊ฒ ์ง€๋งŒ, ์ˆํฌ๋ฆฌํŠธ ๋ผ์ด๋‹์˜ ํ•˜์ค‘์ง€์ง€์„ฑ๋Šฅ์— ๋Œ€ํ•œ ํ•ฉ๋ฆฌ์ ์ด๊ณ  ์ •๊ตํ•œ ํ‰๊ฐ€๊ฐ€ ์„ค๊ณ„ ๋‹จ๊ณ„์—์„œ ์ด๋ฃจ์–ด์ ธ์•ผ ํ•˜๋Š” ๊ฒƒ์€ ๋ถ„๋ช…ํ•˜๋‹ค.

์ถ•๋ ฅ์˜ ์ž‘์šฉ์€ ์ˆํฌ๋ฆฌํŠธ์˜ ํœจ ๊ฐ•์„ฑ์„ ํฌ๊ฒŒ ํ–ฅ์ƒ์‹œํ‚ค๋ฉฐ, ๊ฐ•์ง€๋ณด-์ˆํฌ๋ฆฌํŠธ ๋ถ€์žฌ์˜ ์ตœ๋Œ€ํ•˜์ค‘์„ฑ๋Šฅ ๋ฐ ํ•ฉ์„ฑ๊ฑฐ๋™์— ์ค‘์š”ํ•œ ์˜ํ–ฅ์„ ๋ฏธ์นœ๋‹ค. ๊ทธ๋Ÿฌ๋‚˜ ๊ตญ๋‚ด์™ธ ํ„ฐ๋„ ๋ผ์ด๋‹ ์„ค๊ณ„ ๊ธฐ์ค€์€ ๋Œ€๋ถ€๋ถ„ ํœจ ๋ชจ๋ฉ˜ํŠธ๋งŒ ์ž‘์šฉํ•˜๋Š” ๋ณด ๋ฐ ์Šฌ๋ž˜๋ธŒ์— ๊ทผ๊ฐ„ํ•œ๋‹ค. ASTM, JSCE, ๊ทธ๋ฆฌ๊ณ  EFNARC์€ ์ˆํฌ๋ฆฌํŠธ์˜ ์—ญํ•™์  ์„ฑ๋Šฅ์„ ๋ณด ์‹œํŽธ์— ๋Œ€ํ•œ ํœจ ์‹œํ—˜์„ ํ†ตํ•ด ํ‰๊ฐ€ํ•˜๊ณ  ์žˆ์œผ๋ฉฐ(Lee et al., 2007), ํ•œ๊ตญ๋„๋กœ๊ณต์‚ฌ์—์„œ๋Š” KS F 2408์— ์ค€ํ•œ ์‹œํ—˜๋ฐฉ๋ฒ•์„ ์ œ์‹œํ•˜๊ณ  ์žˆ๋‹ค(Korea Expressway Corporation, 2001). ์ด๋Ÿฌํ•œ ์ด์œ ๋กœ ๋ผ์ด๋‹ ๋ถ€์žฌ์˜ ํ•˜์ค‘์ง€์ง€์„ฑ๋Šฅ์— ๋Œ€ํ•œ ๋Œ€๋ถ€๋ถ„์˜ ์—ฐ๊ตฌ๋“ค์€ ํœจ ์‹œํ—˜์„ ํ† ๋Œ€๋กœ ์ด๋ฃจ์–ด์ ธ ์™”๋‹ค. ์ˆํฌ๋ฆฌํŠธ ๋ถ€์žฌ(Kim et al., 2011; Ji et al., 2011; Park and Kim, 2013)์™€ ๊ฐ•์ง€๋ณด-์ˆํฌ๋ฆฌํŠธ ํ•ฉ์„ฑ๋ถ€์žฌ(Yoo et al., 1997; Lee et al., 2008; Park et al., 2010)์— ๋Œ€ํ•œ ํœจ ์‹œํ—˜์ด ๋‹ค์ˆ˜ ์ˆ˜ํ–‰๋˜์—ˆ์œผ๋‚˜, ์ด๋Ÿฌํ•œ ์ ‘๊ทผ์€ ์ถ•๋ ฅ๊ณผ ํœจ ๋ชจ๋ฉ˜ํŠธ๋ฅผ ๋™์‹œ์— ๋ฐ›๋Š” ๋ผ์ด๋‹์˜ ํ•˜์ค‘์กฐ๊ฑด์„ ๋ฐ˜์˜ํ•˜์ง€ ๋ชปํ•˜๋ฏ€๋กœ ์‹ค์ œ ํœจ ๊ฐ•๋„ ๋ฐ ํŒŒ๊ดด๊ฑฐ๋™ ํ‰๊ฐ€์— ํ•œ๊ณ„๊ฐ€ ์žˆ๋‹ค. ์ด๋Ÿฌํ•œ ํ•œ๊ณ„์ ์„ ๊ทน๋ณตํ•˜๊ธฐ ์œ„ํ•ด ์ตœ๊ทผ ํ„ฐ๋„ ํ˜•์ƒ์„ ๊ฐ–๋Š” ์ฝ˜ํฌ๋ฆฌํŠธ ๋˜๋Š” ์ˆํฌ๋ฆฌํŠธ ์‹คํ—˜์ฒด(Mashimo et al., 2002; You et al., 2008)์™€ ๊ฐ•์ง€๋ณด-์ˆํฌ๋ฆฌํŠธ ์‹คํ—˜์ฒด(Moon et al., 2012)์— ๋Œ€ํ•œ ํ•˜์ค‘์‹คํ—˜์ด ์ˆ˜ํ–‰๋˜๊ธฐ๋„ ํ•˜์˜€์œผ๋‚˜, ๊ฐ•์ง€๋ณด-์ˆํฌ๋ฆฌํŠธ ๋ผ์ด๋‹์˜ ํ•ฉ์„ฑ๊ฑฐ๋™๊ณผ ์ถ•๋ ฅ์— ์˜ํ•œ ์˜ํ–ฅ์ด ์™„์ „ํžˆ ๋ฐํ˜€์ง€์ง€๋Š” ์•Š์€ ์ƒํƒœ์ด๋‹ค.

์ˆํฌ๋ฆฌํŠธ ๋‚ด ๊ฐ•์ง€๋ณด ํšจ๊ณผ๋ฅผ ๋ฐ˜์˜ํ•˜๊ธฐ ์œ„ํ•œ ์ˆ˜์น˜ํ•ด์„ ์—ฐ๊ตฌ๋“ค ๋˜ํ•œ ์ด๋ฃจ์–ด์ ธ์™”๋‹ค. ๊ฐ•์ง€๋ณด์— ์˜ํ•œ ์ˆํฌ๋ฆฌํŠธ ๋ผ์ด๋‹์˜ ์ง€์ง€๋ ฅ ํ–ฅ์ƒ์„ ๊ณ ๋ คํ•˜๊ธฐ ์œ„ํ•ด Ha et al. (2008)๊ณผ Lee et al. (2008)์€ ์„ ํ˜• ํ•ฉ์„ฑ๋ณด ์ด๋ก ์— ๊ทผ๊ฑฐํ•ด ๋“ฑ๊ฐ€๋ฌผ์„ฑ์„ ์‚ฐ์ •ํ•˜๊ณ  ์ด๋ฅผ ์ˆ˜์น˜ํ•ด์„์— ์ ์šฉํ•˜์˜€๋‹ค. ๊ทธ๋Ÿฌ๋‚˜ ์ˆํฌ๋ฆฌํŠธ๋Š” ๋น„์„ ํ˜• ๊ฑฐ๋™์ด ํ˜„์ €ํ•  ๋ฟ๋งŒ ์•„๋‹ˆ๋ผ ๋น„์„ ํ˜• ํŠน์„ฑ์ด ๋ผ์ด๋‹์— ์ž‘์šฉํ•˜๋Š” ์••์ถ•๋ ฅ์— ์˜ํ–ฅ์„ ๋ฐ›๊ธฐ ๋•Œ๋ฌธ์—, ์ด๋Ÿฌํ•œ ์ ‘๊ทผ์€ ์ˆํฌ๋ฆฌํŠธ์˜ ์‹ค์ œ ๊ฑฐ๋™์„ ํ•ฉ๋ฆฌ์ ์œผ๋กœ ๋ชจ์‚ฌํ•˜๋Š”๋ฐ ํ•œ๊ณ„๊ฐ€ ์žˆ๋‹ค. ํ•œํŽธ, Mashimo et al. (2002)๋Š” ์‹คํ—˜๊ณผ ๋”๋ถˆ์–ด ์žฌ๋ฃŒ์  ๋น„์„ ํ˜•์„ฑ์„ ๊ณ ๋ คํ•  ์ˆ˜ ์žˆ๋Š” ์ˆ˜์น˜๋ชจ๋ธ์„ ์ œ์‹œํ•˜์˜€์œผ๋‚˜, ๊ฐ•์ง€๋ณด์˜ ํ•˜์ค‘์ง€์ง€ ๋Šฅ๋ ฅ์„ ํ•ด์„์— ๊ณ ๋ คํ•˜์ง€ ์•Š์•„ ์ œํ•œ์ ์ธ ๊ฑฐ๋™ ๋ถ„์„๋งŒ ์ด๋ฃจ์–ด์กŒ๋‹ค. ์•ž์„œ ์‚ดํŽด๋ณธ ๋ฐ”์™€ ๊ฐ™์ด, ์ˆํฌ๋ฆฌํŠธ ๋ผ์ด๋‹ ํ•ด์„์€ ํ†ต์ƒ ์„ ํ˜• ํ•ฉ์„ฑ๋ณด ์ด๋ก ์— ๊ทผ๊ฐ„ํ•˜๊ฑฐ๋‚˜ ๊ฐ•์ง€๋ณด์˜ ์ง€๋ณดํšจ๊ณผ๋ฅผ ๋ฌด์‹œํ•˜๊ณ  ์žˆ์–ด, ์ˆํฌ๋ฆฌํŠธ-๊ฐ•์ง€๋ณด ํ•ฉ์„ฑ๋ถ€์žฌ์˜ ๋น„์„ ํ˜• ํ•ฉ์„ฑ๊ฑฐ๋™๊ณผ ์ถ•๋ ฅ์˜ ์˜ํ–ฅ์„ ๋ฐ˜์˜ํ•˜๋Š”๋ฐ ์ œํ•œ์ ์ด๋‹ค. ๋”ฐ๋ผ์„œ ์—ฌ๋Ÿฌ ๊ฐ•์ง€๋ณด ์œ ํ˜•์— ๋”ฐ๋ฅธ ํ•ฉ์„ฑ๋ถ€์žฌ์˜ ๊ฑฐ๋™ ํŠน์„ฑ์ด ์ˆ˜์น˜ํ•ด์„์„ ํ†ตํ•ด ํ„ฐ๋„ ์ง€๋ณด์žฌ์˜ ๊ฒฝ์ œ์„ฑ ์ œ๊ณ  ์ธก๋ฉด์—์„œ ๊ฒ€ํ† ๋  ํ•„์š”๊ฐ€ ์žˆ๋‹ค.

์ด๋Ÿฌํ•œ ์ด์œ ๋กœ ๋ณธ ์—ฐ๊ตฌ์—์„œ๋Š” ์••์ถ•๋ ฅ๊ณผ ํœจ ๋ชจ๋ฉ˜ํŠธ๊ฐ€ ๋™์‹œ์— ๋ฐœ์ƒํ•˜๋Š” ๊ฐ•์ง€๋ณด-์ˆํฌ๋ฆฌํŠธ ํ•ฉ์„ฑ๋ถ€์žฌ์˜ ๋น„์„ ํ˜• ๊ฑฐ๋™์„ ์ˆ˜์น˜ํ•ด์„์ ์œผ๋กœ ํ‰๊ฐ€ํ•˜์˜€๋‹ค. ํ”„๋ ˆ์ž„ ์š”์†Œ ๊ธฐ๋ฐ˜์˜ ํ™”์ด๋ฒ„ ๋‹จ๋ฉด ์š”์†Œ(fiber section element)๋ฅผ ์ด์šฉํ•ด ํ„ฐ๋„ ๊ตฌ์กฐ์ฒด๋ฅผ ์ƒ์„ฑํ•˜๊ณ , ๊ทนํ•œ์ƒํƒœ์˜ ์ง€๋ฐ˜-๊ตฌ์กฐ๋ฌผ ์ƒํ˜ธ์ž‘์šฉ์„ ๊ตฌํ˜„ํ•  ์ˆ˜ ์žˆ๋„๋ก ์ง€๋ฐ˜์˜ ๋ณ€ํ˜•๋ฅ  ์—ฐํ™”(strain-softening) ๊ฑฐ๋™์„ ๊ณ ๋ คํ•œ ์ˆ˜์ • hyperbolic ๋ชจ๋ธ์„ ์ง€๋ฐ˜ ์Šคํ”„๋ง ์š”์†Œ์— ์ ์šฉํ•ด ํ„ฐ๋„ ์œ ํ•œ์š”์†Œ๋ชจ๋ธ์„ ํ˜•์„ฑํ•˜์˜€๋‹ค. ๊ฐœ๋ฐœ๋œ ํ•ด์„๋ชจ๋ธ์˜ ๊ฒ€์ฆ๊ณผ ์ˆํฌ๋ฆฌํŠธ์˜ ์—ญํ•™์  ๊ฑฐ๋™์— ๊ด€ํ•œ ์žฌ๋ฃŒ๋ฌผ์„ฑ์„ ๋„์ถœํ•˜๊ธฐ ์œ„ํ•ด ์ถ•๋ ฅ๊ณผ ํœจ์„ ๋™์‹œ์— ๋ฐ›๋Š” ํ•˜์ค‘์กฐ๊ฑด์œผ๋กœ ์ˆ˜ํ–‰๋œ ์‹คํ—˜๊ฒฐ๊ณผ(Mashimo et al., 2002)์— ๋Œ€ํ•ด ์—ญํ•ด์„์„ ์ˆ˜ํ–‰ํ•˜์˜€๋‹ค. ํ•ด์„๋ชจ๋ธ์„ ํ™œ์šฉํ•˜์—ฌ Hํ˜•๊ฐ•, ๋‹จ์ฒ ๊ทผ, ๋ณต์ฒ ๊ทผ์œผ๋กœ ๋ณด๊ฐ•๋œ ์ˆํฌ๋ฆฌํŠธ ๋‹จ๋ฉด์— ๋Œ€ํ•œ ํ•ด์„์„ ์ˆ˜ํ–‰ํ•˜์—ฌ, ๊ฐ•์ง€๋ณด ์œ ํ˜•์— ๋”ฐ๋ฅธ ์ง€๋ณดํšจ๊ณผ์™€ ์ฃผ๋ณ€ ์ง€๋ฐ˜๊ณผ์˜ ์ƒํ˜ธ์ž‘์šฉ์— ๋ฏธ์น˜๋Š” ์˜ํ–ฅ์„ ๋ถ„์„ํ•˜์˜€๋‹ค.

2. ๋น„์„ ํ˜• ์œ ํ•œ์š”์†Œ ํ•ด์„ ๋ชจ๋ธ

2.1 ํ„ฐ๋„ ๊ตฌ์กฐ์ฒด

2.1.1 ํ™”์ด๋ฒ„ ๋‹จ๋ฉด ์š”์†Œ

ํ”„๋ ˆ์ž„ ์š”์†Œ์— ๋ฐ”ํƒ•์„ ๋‘” ํ™”์ด๋ฒ„ ๋‹จ๋ฉด ์š”์†Œ๋Š” Fig. 1๊ณผ ๊ฐ™์ด ํ”„๋ ˆ์ž„ ์š”์†Œ ๋‹จ๋ฉด์„ ์—ฌ๋Ÿฌ ๊ฐœ์˜ ํ™”์ด๋ฒ„๋กœ ๋ถ„ํ• ํ•˜๊ณ , ๊ฐ ํ™”์ด๋ฒ„์— ๋Œ€ํ•ด ์žฌ๋ฃŒ์˜ 1์ถ• ์‘๋ ฅ-๋ณ€ํ˜•๋ฅ  ๊ด€๊ณ„๋ฅผ ์ •์˜ํ•จ์œผ๋กœ์„œ ํ•ฉ์„ฑ๊ฑฐ๋™์„ ๊ตฌํ˜„ํ•˜๊ฒŒ ๋œ๋‹ค. ์š”์†Œ ๋‚ด ์ˆ˜์น˜์ ๋ถ„์ ์—์„œ ์ถ• ๋ณ€ํ˜•๋ฅ ๊ณผ ๊ณก๋ฅ ์ด ์ฃผ์–ด์ง€๋ฉด, ์ด๋ฅผ ์ด์šฉํ•ด ํ™”์ด๋ฒ„์˜ ์ˆ˜์ง ๋ณ€ํ˜•๋ฅ ์„ ์‚ฐ์ •ํ•˜๊ณ  ํ™”์ด๋ฒ„์— ํ• ๋‹น๋œ ๊ตฌ์„ฑ๋ฐฉ์ •์‹์œผ๋กœ๋ถ€ํ„ฐ ์‘๋ ฅ ๋ฐ ์‘๋ ฅ ํ•ฉ(resultant forces), ๊ทธ๋ฆฌ๊ณ  ๋‹จ๋ฉด ๊ฐ•์„ฑํ–‰๋ ฌ์„ ๊ณ„์‚ฐํ•œ๋‹ค. ํ™”์ด๋ฒ„ ๋‹จ๋ฉด ์š”์†Œ๋Š” ์ ์€ ์ „์‚ฐ๋น„์šฉ์œผ๋กœ ์žฌ๋ฃŒ์  ๋น„์„ ํ˜•์„ฑ์„ ๊ณ ๋ คํ•œ ๋‹ค์–‘ํ•œ ํ•ฉ์„ฑ๋‹จ๋ฉด ๊ฑฐ๋™์„ ์žฌํ˜„ํ•ด ๋‚ผ ์ˆ˜ ์žˆ์–ด, ๊ฐ•์žฌ ๋ณด๊ฐ•๋œ ์ˆํฌ๋ฆฌํŠธ ํ„ฐ๋„ ๋ผ์ด๋‹๊ณผ ๊ฐ™์ด ์ง€๋ฐ˜-๊ตฌ์กฐ๋ฌผ์˜ ์ƒํ˜ธ์ž‘์šฉ์ด ์ค‘์š”ํ•œ ๋ฌธ์ œ์— ๋Œ€ํ•ด ์ ํ•ฉํ•˜๋ฉฐ, ํšจ์œจ์ ์ธ ํ•ด์„์ด ๊ฐ€๋Šฅํ•˜๋‹ค. ๋˜ํ•œ ํ„ฐ๋„ ๋ผ์ด๋‹ ์„ค๊ณ„์—์„œ ๋„๋ฆฌ ์‚ฌ์šฉ๋˜๋Š” ๋ณด-์Šคํ”„๋ง ๋ชจ๋ธ์— ์ ์šฉํ•  ์ˆ˜ ์žˆ๋Š” ์žฅ์ ์„ ๊ฐ€์ง„๋‹ค.

Fig. 1.

Fiber Section Element (Kim et al., 2014)

Figure_KSCE_37_02_09_F1.jpg

ํ™”์ด๋ฒ„ ๋‹จ๋ฉด ์š”์†Œ์˜ ์ •์‹ํ™”๋Š” ๊ฐ•์„ฑ๋„๋ฒ•, ์œ ์—ฐ๋„๋ฒ• ์˜ํ•ด ์ด๋ค„์งˆ ์ˆ˜ ์žˆ๋Š”๋ฐ, ํ†ต์ƒ ์œ ์—ฐ๋„๋ฒ•์ด ๋„๋ฆฌ ์‚ฌ์šฉ๋œ๋‹ค. ์œ ์—ฐ๋„๋ฒ•์— ์˜ํ•œ ์ •์‹ํ™”๋Š” ์•ž์„œ ๊ฒฐ์ •๋œ ๋‹จ๋ฉด ๊ฐ•์„ฑํ–‰๋ ฌ์„ ์ด์šฉํ•ด ๋‹จ๋ฉด ์œ ์—ฐ๋„ ํ–‰๋ ฌ์„ ๊ตฌํ•˜๊ณ , ์ด๋ฅผ ํž˜ ํ˜•์ƒํ•จ์ˆ˜๋ฅผ ์ด์šฉํ•ด ์š”์†Œ ์œ ์—ฐ๋„ ํ–‰๋ ฌ์„ ๊ฒฐ์ •ํ•œ๋‹ค. ์ผ๋ฐ˜์ ์ธ ์œ ํ•œ์š”์†Œํ•ด์„์€ ๊ฐ•์„ฑ๋„๋ฒ•์— ์˜ํ•ด ์ด๋ค„์ง€๋ฏ€๋กœ, ์š”์†Œ ์œ ์—ฐ๋„ ํ–‰๋ ฌ์€ ์š”์†Œ ๊ฐ•์„ฑํ–‰๋ ฌ๋กœ ๋ณ€ํ™˜๋œ๋‹ค. ์ผ๋ฐ˜์ ์ธ ๊ฐ•์„ฑ๋„๋ฒ• ๊ธฐ๋ฐ˜์˜ ์œ ํ•œ์š”์†Œ ์ •์‹ํ™”์™€ ๋‹ฌ๋ฆฌ ๋ณ€์œ„ ํ˜•์ƒํ•จ์ˆ˜๋ฅผ ์‚ฌ์šฉํ•˜์ง€ ์•Š๊ธฐ ๋•Œ๋ฌธ์— ์ถ• ๋ณ€ํ˜•๋ฅ ๊ณผ ๊ณก๋ฅ ์„ ์ ˆ์ ๋ณ€์œ„๋กœ๋ถ€ํ„ฐ ์ง์ ‘ ์‚ฐ์ •ํ•  ์ˆ˜ ์—†๋‹ค. ์ด๋กœ ์ธํ•ด ์š”์†Œ์ƒํƒœ ๊ฒฐ์ •์„ ์œ„ํ•œ ๋ฐ˜๋ณต๊ณ„์‚ฐ์ด ์ˆ˜๋ฐ˜๋˜์ง€๋งŒ, ์ ์€ ์š”์†Œ๋งŒ์œผ๋กœ๋„ ์žฌ๋ฃŒ์˜ ๋น„์„ ํ˜• ๊ฑฐ๋™์„ ํšจ๊ณผ์ ์œผ๋กœ ํ‰๊ฐ€ํ•  ์ˆ˜ ์žˆ์–ด ๋„๋ฆฌ ์‚ฌ์šฉ๋˜๊ณ  ์žˆ๋‹ค. ์œ„์˜ ํ™”์ด๋ฒ„ ๋‹จ๋ฉด ์š”์†Œ ์ •์‹ํ™”๋Š” ์œ ์—ฐ๋„๋ฒ•์— ๊ธฐ๋ฐ˜ ํ•˜์ง€๋งŒ, ์ตœ์ข…์ ์ธ ํ•ด์˜ ๊ฒฐ์ •์„ ์œ„ํ•ด ๊ฐ•์„ฑ๋„๋ฒ• ํ˜•ํƒœ๋กœ ์ „ํ™˜๋˜๋ฏ€๋กœ, ํ˜ผํ•ฉ๋ฒ•์ด๋ผ ๋ถˆ๋ฆฌ๊ธฐ๋„ ํ•œ๋‹ค. ํ™”์ด๋ฒ„ ๋‹จ๋ฉด ์š”์†Œ์— ๋Œ€ํ•œ ์ƒ์„ธํ•œ ์ •์‹ํ™” ๊ณผ์ • ๋ฐ ์ „์ฒด ํ•ด์„ ํ”„๋กœ์„ธ์Šค๋Š” ๊ด€๋ จ ์—ฐ๊ตฌ(Taucer et al., 1991; Spacone et al., 1996; Filippou et al., 1999; Kim et al., 2014)๋ฅผ ์ฐธ๊ณ ํ•  ์ˆ˜ ์žˆ๋‹ค.

2.1.2 ์ˆํฌ๋ฆฌํŠธ ๊ตฌ์„ฑ๋ฐฉ์ •์‹

์ˆํฌ๋ฆฌํŠธ๋Š” ๋‚ฎ์€ ์ธ์žฅ๊ฐ•๋„์™€ ์ทจ์„ฑ์  ์žฌ๋ฃŒํŠน์„ฑ์„ ๊ฐ€์ง€๊ณ  ์žˆ๊ธฐ ๋•Œ๋ฌธ์— ๊ฐ•์„ฌ์œ ๋ฅผ ํ˜ผ์ž…ํ•˜๋Š” ๊ฒƒ์ด ๋ณดํŽธ์ ์ด๋‹ค. ๊ฐ•์„ฌ์œ ์— ์˜ํ•œ ์ธ์žฅ๋ณด๊ฐ•ํšจ๊ณผ๋ฅผ ๊ณ ๋ คํ•ด ์ˆํฌ๋ฆฌํŠธ์˜ ๊ตฌ์„ฑ๋ฐฉ์ •์‹์€ ์••์ถ•์˜์—ญ๊ณผ ์ธ์žฅ์˜์—ญ์— ๋Œ€ํ•ด ๊ฐ๊ฐ Kent & Park (Kent and Park, 1971) ๋ชจ๋ธ๊ณผ Linear softening ๋ชจ๋ธ(Darvall and Mendis, 1985)์„ ์ ์šฉํ•˜์˜€๋‹ค. Fig. 2๋Š” ์ˆํฌ๋ฆฌํŠธ์˜ ๊ตฌ์„ฑ๋ฐฉ์ •์‹์„ ๋‚˜ํƒ€๋‚ด๋ฉฐ, ์—ฌ๊ธฐ์„œ PIC1ED2.gif์™€ PIC1EE3.gif๋Š” ์ˆํฌ๋ฆฌํŠธ์˜ ์ตœ๋Œ€ ์••์ถ•๊ฐ•๋„์™€ ์ด๋•Œ์˜ ๋ณ€ํ˜•๋ฅ , PIC1EF3.gif์™€ PIC1F04.gif๋Š” ์ˆํฌ๋ฆฌํŠธ์˜ ์ž”๋ฅ˜ ์••์ถ•๊ฐ•๋„์™€ ์ด๋•Œ์˜ ๋ณ€ํ˜•๋ฅ , PIC1F24.gif์™€ PIC1F35.gif๋Š” ์ตœ๋Œ€ ์ธ์žฅ๊ฐ•๋„์™€ ์ด๋•Œ์˜ ๋ณ€ํ˜•๋ฅ , PIC1F45.gif๋Š” ๊ทนํ•œ ์ธ์žฅ๋ณ€ํ˜•๋ฅ ์ด๋‹ค. ์œ„์˜ ๊ตฌ์„ฑ๋ฐฉ์ •์‹ ๋ชจ๋ธ์€ ์ฃผ๋กœ ์ฝ˜ํฌ๋ฆฌํŠธ ์žฌ๋ฃŒ์— ์‚ฌ์šฉ๋˜์ง€๋งŒ, ๊ฐ•์„ฌ์œ  ๋ณด๊ฐ•๋œ ์Šต์‹ ์ˆํฌ๋ฆฌํŠธ์™€ ์ฝ˜ํฌ๋ฆฌํŠธ๊ฐ€ ์œ ์‚ฌํ•œ ๊ฑฐ๋™ ํŠน์„ฑ์„ ๋ณด์ธ๋‹ค๋Š” ์—ฐ๊ตฌ ๊ฒฐ๊ณผ(Leung et al., 2005)์— ๊ทผ๊ฑฐํ•˜์—ฌ ๋ณธ ์—ฐ๊ตฌ์—์„œ ํ™œ์šฉ๋˜์—ˆ๋‹ค.

Fig. 2.

Constitutive Model for Shotcrete

Figure_KSCE_37_02_09_F2.jpg

2.1.3 ๊ฐ•์žฌ ๊ตฌ์„ฑ๋ฐฉ์ •์‹

๊ฐ•์žฌ๋Š” ๋ชจ๋‘ ์„ ํ˜• ๋“ฑ๋ฐฉ๊ฒฝํ™”(Linear isotropic hardening) ์žฌ๋ฃŒ๋กœ ์ •์˜๋˜์—ˆ๋‹ค.

Fig. 3์€ ์„ ํ˜• ๋“ฑ๋ฐฉ๊ฒฝํ™”๋ชจ๋ธ์˜ ๋ชจ์‹๋„๋กœ PIC1F56.gif๋Š” ๊ฐ•์žฌ ํƒ„์„ฑ๊ณ„์ˆ˜, PIC1F67.gif๋Š” ๊ฐ•์žฌ ํ•ญ๋ณต์‘๋ ฅ, PIC1F77.gif๋Š” ๊ฐ•์žฌ์˜ ๊ฒฝํ™”๊ณ„์ˆ˜๋ฅผ ์˜๋ฏธํ•œ๋‹ค.

Fig. 3.

Constitutive Model for Steel

Figure_KSCE_37_02_09_F3.jpg

2.2 ์ง€๋ฐ˜โ€“๊ตฌ์กฐ๋ฌผ ์ƒํ˜ธ์ž‘์šฉ

ํ”„๋ ˆ์ž„ ์š”์†Œ๋ฅผ ํ™œ์šฉํ•œ ํ„ฐ๋„ ํ•ด์„๋ชจ๋ธ์—์„œ ํ„ฐ๋„ ๋ผ์ด๋‹๊ณผ ์ฃผ๋ณ€ ์ง€๋ฐ˜ ๊ฐ„์˜ ์ƒํ˜ธ์ž‘์šฉ์€ ์ข…์ข… ๋ฒ•์„ ๋ฐฉํ–ฅ ์Šคํ”„๋ง์— ์˜ํ•ด ๋ชจ๋ธ๋ง ๋œ๋‹ค(ITA, 1988; Kim and Park, 2009). ํ„ฐ๋„ ์ฒœ์ •๋ถ€์™€ ๊ฐ™์ด ์ง€๋ฐ˜ ์ง€์ง€๋ ฅ ์ƒ์‹ค์ด ์˜ˆ์ƒ๋˜๋Š” ์˜์—ญ์„ ๊ณ ๋ คํ•˜๊ธฐ ์œ„ํ•ด, ์••์ถ• ์ „๋‹ด ์Šคํ”„๋ง ์š”์†Œ๋ฅผ ์‚ฌ์šฉํ•˜์˜€๋‹ค. ์Šคํ”„๋ง ์š”์†Œ๋ฅผ ๋ผ์ด๋‹๊ณผ ์ง๊ฐ์„ ์ด๋ฃจ๋„๋ก ์ƒ์„ฑํ•˜์—ฌ ์ˆ˜์ง(normal) ์ง€๋ฐ˜ ์ง€์ง€๋ ฅ๋งŒ ์ „๋‹ฌ๋  ์ˆ˜ ์žˆ๋„๋ก ํ•˜์˜€๋‹ค. Fig. 4์— ๋‚˜ํƒ€๋‚ธ ๋ฐ”์™€ ๊ฐ™์ด, ์ ˆ์  PIC1F88.gif์— ์—ฐ๊ฒฐ๋œ ์Šคํ”„๋ง ๊ฐ•์„ฑ PIC1F99.gif๋Š” ์ธ์ ‘ํ•œ ํ”„๋ ˆ์ž„ ์š”์†Œ์˜ ๊ธธ์ด์™€ ํญ์— ์˜ํ•ด ์˜ํ–ฅ์„ ๋ฐ›์œผ๋ฉฐ, Eq. (1)๊ณผ ๊ฐ™์ด ๊ธฐ์ˆ ๋œ๋‹ค.

PIC1FB9.gif (1)

Fig. 4.

Ground-Structure Interaction through Normal Spring (Oreste, 2007)

Figure_KSCE_37_02_09_F4.jpg

์—ฌ๊ธฐ์„œ PIC1FC9.gif๋Š” ๋น„์„ ํ˜• ์ง€๋ฐ˜๋ฐ˜๋ ฅ๊ณ„์ˆ˜(์ง€์ง€๋ ฅ-๋ณ€์œ„ ์„ ๋„์˜ ์ ‘์„  ๊ธฐ์šธ๊ธฐ), PIC1FDA.gif์™€ PIC1FEB.gif๋Š” ์Šคํ”„๋ง PIC1FFB.gif์˜ ์ขŒยท์šฐ์— ์ธ์ ‘ํ•œ ํ”„๋ ˆ์ž„ ์š”์†Œ์˜ ๊ธธ์ด, ๊ทธ๋ฆฌ๊ณ  PIC200C.gif๋Š” ํ”„๋ ˆ์ž„ ์š”์†Œ์˜ ํญ์ด๋‹ค.

์ง€๋ฐ˜์˜ ๋น„์„ ํ˜• ๊ฑฐ๋™ ๋ฐ ํ•ญ๋ณต์„ ๋ชจ์‚ฌํ•˜๊ธฐ ์œ„ํ•ด hyperbolic ๋ชจ๋ธ์ด ์ข…์ข… ์‚ฌ์šฉ๋œ๋‹ค(Oreste, 2007; Do et al., 2014). ๊ทธ๋Ÿฌ๋‚˜ ์ด ๋ชจ๋ธ์€ ์ง€๋ฐ˜์˜ ๊ฒฝํ™”๋งŒ ๊ณ ๋ คํ•  ์ˆ˜ ์žˆ๊ธฐ ๋•Œ๋ฌธ์—, ์ง€๋ฐ˜-๊ตฌ์กฐ๋ฌผ ์ƒํ˜ธ์ž‘์šฉ์„ ๊ณ ๋ คํ•˜๊ธฐ์—๋Š” ํ•œ๊ณ„๊ฐ€ ์žˆ๋‹ค. ํŠนํžˆ, ํ„ฐ๋„ ๊ตฌ์กฐ๋ฌผ์ด ๊ทนํ•œ์ƒํƒœ์— ์ด๋ฅด๋ €์Œ์—๋„ ์ธ์ ‘ ์ง€๋ฐ˜์ด ๊ณ„์† ๊ฒฝํ™”๋งŒ ๋ฐœ์ƒํ•˜๋Š” ๊ฒƒ์€ ์‹ค์ œ์ ์œผ๋กœ ๋ถˆ๊ฐ€๋Šฅํ•˜๋‹ค๋Š” ์ ์—์„œ, ์ธ์ ‘ ์ง€๋ฐ˜์˜ ๋ณ€ํ˜•๋ฅ  ์—ฐํ™” ๊ฑฐ๋™์„ ์ง€๋ฐ˜๋ชจ๋ธ์— ๋ฐ˜์˜ํ•  ํ•„์š”๊ฐ€ ์žˆ๋‹ค. ์ด๋Ÿฌํ•œ ์ด์œ ๋กœ, ๋ณธ ์—ฐ๊ตฌ๋Š” Fig. 5์˜ ์ˆ˜์ •๋œ hyperbolic ๋ชจ๋ธ์„ ์‚ฌ์šฉํ•˜์—ฌ ์ง€๋ฐ˜ ์ง€์ง€๋ ฅ์„ ๋ชจ์‚ฌํ•˜์˜€๋‹ค.

Fig. 5.

Modified Hyperbolic Model for Ground Reaction

Figure_KSCE_37_02_09_F5.jpg

์—ฌ๊ธฐ์„œ PIC202C.gif๋Š” ๋‹จ์œ„๋ฉด์ ๋‹น ์ž‘์šฉํ•˜๋Š” ์ง€๋ฐ˜์˜ ์ƒํ•œ๊ณ„ ๋ฐ˜๋ ฅ, PIC203D.gif์™€ PIC204D.gif๋Š” ๋‹จ์œ„๋ฉด์  ๋‹น ์ž‘์šฉํ•˜๋Š” ์ตœ๋Œ€ ์ง€๋ฐ˜๋ฐ˜๋ ฅ๊ณผ ์ด ๋•Œ ๋ฐœ์ƒ๋˜๋Š” ๋ฒ•์„ ๋ฐฉํ–ฅ ์ง€๋ฐ˜๋ณ€์œ„, PIC205E.gif์™€ PIC206F.gif๋Š” ๋‹จ์œ„๋ฉด์  ๋‹น ์ž‘์šฉํ•˜๋Š” ์ž”๋ฅ˜ ์ง€๋ฐ˜๋ฐ˜๋ ฅ๊ณผ ์ด ๋•Œ ๋ฐœ์ƒ๋˜๋Š” ๋ฒ•์„ ๋ฐฉํ–ฅ ์ง€๋ฐ˜๋ณ€์œ„, PIC207F.gif๋Š” ๋ฐ˜๋ ฅ-๋ณ€์œ„ ์„ ๋„์˜ ์ดˆ๊ธฐ ๊ธฐ์šธ๊ธฐ(์ง€๋ฐ˜๋ฐ˜๋ ฅ๊ณ„์ˆ˜)์ด๋‹ค. ์ด ๋ชจ๋ธ์—์„œ ์ดˆ๊ธฐ ๊ฒฝํ™”๊ตฌ๊ฐ„๊ณผ PIC2090.gif ์ดํ›„ ๋ณ€ํ˜•๋ฅ  ์—ฐํ™” ๊ตฌ๊ฐ„์€ ๊ฐ๊ฐ ๊ธฐ์กด hyperbolic ๋ชจ๋ธ๊ณผ ์„ ํ˜• ๋ณ€ํ˜•๋ฅ  ์—ฐํ™” ๋ชจ๋ธ์ด ์ ์šฉ๋˜์—ˆ์œผ๋ฉฐ, ์ž…๋ ฅ๋ณ€์ˆ˜์˜ ๊ฒฐ์ •์— ๊ด€ํ•œ ์ž์„ธํ•œ ์‚ฌํ•ญ์€ Oreste (2007)๊ณผ Lee et al. (2007)์„ ๊ฐ๊ฐ ์ฐธ๊ณ ํ•  ์ˆ˜ ์žˆ๋‹ค.

3. ์ˆํฌ๋ฆฌํŠธ์˜ ์žฌ๋ฃŒ๋ชจ๋ธ๊ณผ ๋ฌผ์„ฑ ๊ฒฐ์ •

3.1 ์ถ•๋ ฅ๊ณผ ํœจ ๋ชจ๋ฉ˜ํŠธ๋ฅผ ๋ฐ›๋Š” ์ˆํฌ๋ฆฌํŠธ ๋ถ€์žฌ์˜ ํ•˜์ค‘ ์‹คํ—˜

์ˆํฌ๋ฆฌํŠธ์˜ ๋ชจ๋ธ์— ๋Œ€ํ•œ ์žฌ๋ฃŒ ๋ฌผ์„ฑ์„ ์—ญํ•ด์„์œผ๋กœ ๊ฒฐ์ •ํ•˜๊ธฐ ์œ„ํ•ด Mashimo et al. (2002)์˜ ํ„ฐ๋„๋ชจํ˜•์‹คํ—˜ ๊ฒฐ๊ณผ๋ฅผ ์ด์šฉํ•˜์˜€๋‹ค. Mashimo et al. (2002)์€ ์•„์น˜ํ˜• ์‹คํ—˜์ฒด์— ์—ฌ๋Ÿฌ ๊ฐœ์˜ ์œ ์••์žญ์„ ์‚ฌ์šฉํ•ด ์‹ค์ œ์ ์ธ ์ง€๋ฐ˜ํ•˜์ค‘์„ ๋ชจ์‚ฌํ•˜์˜€๋‹ค. ํŠนํžˆ, ์•„์น˜ํ˜• ์‹คํ—˜์ฒด ํ˜•์ƒ ๋•Œ๋ฌธ์— ์ถ•๋ ฅ๊ณผ ํœจ๋ชจ๋ฉ˜ํŠธ๊ฐ€ ๋™์‹œ์— ๋ฐœ์ƒํ•  ์ˆ˜ ์žˆ๋Š” ์กฐ๊ฑด์ด๋ฏ€๋กœ, ๊ธฐ์กด์˜ 3์  ํœจ ์‹œํ—˜ ๋ฐฉ์‹์— ์˜ํ•œ ์ˆํฌ๋ฆฌํŠธ ๋ถ€์žฌ ํ‰๊ฐ€๋ฒ•๋ณด๋‹ค ์‹ค์ œ์ ์ธ ๋ผ์ด๋‹ ํ•˜์ค‘ ์ƒํƒœ๋ฅผ ์žฌํ˜„ํ•  ์ˆ˜ ์žˆ๋‹ค. ์ด ์‹คํ—˜์—์„œ ์‚ฌ์šฉ๋œ ์ˆํฌ๋ฆฌํŠธ๋Š” ์ผ์ถ•์••์ถ•๊ฐ•๋„ 21.2 MPa๋กœ ์„ค๊ณ„๋˜์—ˆ์œผ๋ฉฐ, ๊ฐ•์ง€๋ณด์žฌ์˜ ํƒ€์„ค์—†์ด 0.8PIC20A1.gifร—60 mm ๊ทœ๊ฒฉ์˜ ๊ฐ•์„ฌ์œ ๋กœ ๋ณด๊ฐ•๋˜์—ˆ๋‹ค. ํ•˜์ค‘์‹คํ—˜์€ ์ง๊ฒฝ 9700 mm, ํญ 1000 mm, ๋‘๊ป˜ 300 mm๋ฅผ ๊ฐ–๋Š” ๋ฐ˜์›ํ˜• ๋ชจ์–‘์œผ๋กœ ์ œ์ž‘๋œ ์‹คํ—˜์ฒด์˜ ์ขŒยท์šฐ์ธก(10~40ยฐ) 8๊ณณ์— ์œ ์••์‹ค๋ฆฐ๋”๋กœ ํ•˜์ค‘(10 kN/jack)์„ ๊ฐ€ํ•œ ํ›„, ์ฒœ๋‹จ๋ถ€์—์„œ ๋ณ€์œ„ํ•˜์ค‘์„ ์ถ”๊ฐ€ํ•˜๋Š” ๋ฐฉ์‹์œผ๋กœ ์ˆ˜ํ–‰๋˜์—ˆ๋‹ค.

3.2 ์—ญํ•ด์„์„ ํ†ตํ•œ ์ˆํฌ๋ฆฌํŠธ ์žฌ๋ฃŒ๋ฌผ์„ฑ ๊ฒฐ์ •

์‹œ๋ฉ˜ํŠธ ๊ณ„์—ด ์žฌ๋ฃŒ๋“ค์˜ ๋ฌผ์„ฑ ํ‰๊ฐ€์—์„œ ํŠนํžˆ ์–ด๋ ค์šด ๋ถ€๋ถ„์€ ์ธ์žฅ์— ๊ด€๋ จ๋œ ์—ญํ•™์  ํŠน์„ฑ์„ ๊ฒฐ์ •ํ•˜๋Š” ๊ฒƒ์ด๋‹ค. ํ™”์ด๋ฒ„ ๋‹จ๋ฉด ์š”์†Œ์—์„œ ํ™œ์šฉ๋˜๋Š” ์žฌ๋ฃŒ๋ชจ๋ธ์€ ๊ธฐ๋ณธ์ ์œผ๋กœ 1์ถ• ํ•˜์ค‘์กฐ๊ฑด ํ•˜์—์„œ ์–ป์–ด์ง„ ์‘๋ ฅ-๋ณ€ํ˜•๋ฅ  ๊ด€๊ณ„์ด๊ธฐ ๋•Œ๋ฌธ์—, ๊ธฐ์กด ํœจ ์‹œํ—˜์— ์˜ํ•ด ๋„์ถœ๋œ ์žฌ๋ฃŒ ๋ฌผ์„ฑ์€ ์ ์šฉ์— ํ•œ๊ณ„๊ฐ€ ์žˆ๋‹ค. ์ธ์žฅ ๋ณ€ํ˜•๋ฅ  ๋˜ํ•œ ์ธก์ •์ด ์šฉ์ดํ•˜์ง€ ์•Š๋‹ค. ์ด๋Ÿฌํ•œ ์ด์œ ๋กœ Elsaigh et al. (2011)์˜ ์—ญํ•ด์„ ๋ฐฉ๋ฒ•์— ๊ฐ•์„ฌ์œ  ๋ณด๊ฐ•์— ๋”ฐ๋ฅธ ์˜ํ–ฅ์— ๋Œ€ํ•œ Kim et al. (2014)์˜ ๊ฐ€์ •์„ ์ ์šฉํ•ด ์ˆํฌ๋ฆฌํŠธ์˜ ์žฌ๋ฃŒ๋ฌผ์„ฑ์„ ๊ฒฐ์ •ํ•˜์˜€๋‹ค. ์ด ๋ฐฉ๋ฒ•์€ ์‹คํ—˜์— ์˜ํ•ด ๋„์ถœ๋œ ํ•˜์ค‘-๋ณ€์œ„ ์„ ๋„์™€ ๊ฐ€์ •๋œ ํ•ด์„๋ชจ๋ธ์˜ ๊ฒฐ๊ณผ๊ฐ€ ์ผ์น˜ํ•  ๋•Œ๊นŒ์ง€ ์žฌ๋ฃŒ ๊ตฌ์„ฑ๋ฐฉ์ •์‹์˜ ์ž…๋ ฅ๋ณ€์ˆ˜๋ฅผ ๋ฐ”๊พธ์–ด๊ฐ€๋ฉฐ ์ˆ˜์น˜ํ•ด์„์„ ๋ฐ˜๋ณต์ ์œผ๋กœ ์ˆ˜ํ–‰ํ•จ์œผ๋กœ์จ ์žฌ๋ฃŒ๋ฌผ์„ฑ์„ ์ถ”์ •ํ•˜๋Š” ๋ฐฉ๋ฒ•์ด๋‹ค. ๋ณธ ์—ฐ๊ตฌ์—์„œ๋Š” ์‹คํ—˜์„ ํ†ตํ•ด ์ถ”์ •์ด ์–ด๋ ค์šด PIC20B1.gif, PIC20D1.gif, PIC20E2.gif, PIC2102.gif๋ฅผ ์—ญํ•ด์„์˜ ๋ชฉํ‘œ๋ณ€์ˆ˜๋กœ ์„ค์ •ํ•˜์˜€๋‹ค. ์‹คํ—˜์— ์˜ํ•œ ์ธก์ •์ด ์šฉ์ดํ•œ PIC2113.gif๋Š” ๋ชฉํ‘œ๋ณ€์ˆ˜์—์„œ ์ œ์™ธ๋˜์—ˆ์œผ๋ฉฐ, PIC2133.gif๋Š” ์ผ๋ฐ˜์ ์ธ ์‚ฌ์šฉ๋˜๋Š” ์••์ถ•๋ณ€ํ˜•๋ฅ  0.002๋ฅผ ๊ฐ€์ •ํ•˜์˜€๋‹ค. ์ผ๋ฐ˜์ ์œผ๋กœ PIC2144.gif๋Š” ์••์ถ•์˜์—ญ์˜ ์ดˆ๊ธฐ ์‘๋ ฅ-๋ณ€ํ˜•๋ฅ  ์„ ๋„์˜ ๊ธฐ์šธ๊ธฐ๊ฐ€ ์ธ์žฅ์˜์—ญ์˜ ๊ฒƒ๊ณผ ๋™์ผํ•˜๋‹ค๋Š” ๊ฐ€์ •์„ ์‚ฌ์šฉํ•ด ๊ฒฐ์ •๋˜๋ฉฐ, ๋ณธ ์—ฐ๊ตฌ์—์„œ๋„ ์ด ๊ฐ€์ •์„ ์‚ฌ์šฉํ•˜์˜€๋‹ค.

์ˆํฌ๋ฆฌํŠธ์˜ ์ตœ์ข…์ ์ธ ์ž…๋ ฅ๋ฌผ์„ฑ์ด ์ˆ˜์น˜ํ•ด์„๊ณผ ์‹คํ—˜ ๊ฒฐ๊ณผ์˜ ๋น„๊ต๋ฅผ ํ†ตํ•ด ๊ฒฐ์ •๋˜๊ธฐ ๋•Œ๋ฌธ์—, ์ž…๋ ฅ๋ฌผ์„ฑ์„ ์ •๋Ÿ‰์ ์œผ๋กœ ํ‰๊ฐ€ํ•ด์ฃผ๋Š” ์ง€ํ‘œ๊ฐ€ ํ•„์š”ํ•˜๋ฉฐ, ์ด๋ฅผ ์œ„ํ•ด ๊ฒฐ์ •๊ณ„์ˆ˜ PIC2154.gif (coefficient of determination)์ด ์‚ฌ์šฉ๋˜์—ˆ๋‹ค. ์ˆ˜์น˜ํ•ด์„์„ ํ†ตํ•ด ์–ป์€ ํ•˜์ค‘-๋ณ€์œ„์„ ๋„๋ฅผ ์‹คํ—˜ ๊ฒฐ๊ณผ์— ๋Œ€ํ•œ ํšŒ๊ท€์‹์œผ๋กœ ๊ณ ๋ คํ•˜์—ฌ PIC2165.gif์„ ๊ณ„์‚ฐํ•˜์˜€๋‹ค. PIC2176.gif์ด 1์— ๊ฐ€๊นŒ์›Œ์งˆ์ˆ˜๋ก ๊ฐ€์ •๋œ ์ž…๋ ฅ ๋ฌผ์„ฑ์ด ์‹คํ—˜์— ์‚ฌ์šฉ๋œ ์ˆํฌ๋ฆฌํŠธ๋ฅผ ์ž˜ ๋ชจ์‚ฌํ•˜๊ณ  ์žˆ์Œ์„ ์˜๋ฏธํ•˜๋ฉฐ, ๋ณธ ์—ฐ๊ตฌ์—์„œ๋Š” PIC2186.gif์ธ ์ˆํฌ๋ฆฌํŠธ ๋ฌผ์„ฑ์ด ์‚ฌ์šฉ๋˜์—ˆ๋‹ค.

์—ญํ•ด์„์— ์˜ํ•œ ์ˆํฌ๋ฆฌํŠธ ์žฌ๋ฃŒ๋ฌผ์„ฑ์„ ๊ฒฐ์ •ํ•˜๊ธฐ ์œ„ํ•ด Fig. 6๊ณผ ๊ฐ™์ด ์‹คํ—˜์กฐ๊ฑด๊ณผ ๋™์ผํ•˜๊ฒŒ ์œ ํ•œ์š”์†Œ๋ชจ๋ธ์„ ์ƒ์„ฑํ•˜์˜€๋‹ค. ํ•ด์„๋ชจ๋ธ์€ 18๊ฐœ์˜ ํ™”์ด๋ฒ„ ๋‹จ๋ฉด ์š”์†Œ๋กœ ๊ตฌ์„ฑ๋˜๋ฉฐ, ์š”์†Œ ๋‹จ๋ฉด์€ ๊ฐ€๋กœ๋ฐฉํ–ฅ์œผ๋กœ 4๊ฐœ, ๊นŠ์ด๋ฐฉํ–ฅ์œผ๋กœ 16๊ฐœ์˜ ํ™”์ด๋ฒ„๋กœ ๋ถ„ํ• ๋˜์—ˆ๋‹ค. ํ•ฉ์„ฑ ์ง€๋ณด์— ๋Œ€ํ•œ ํ•ด์„๋ชจ๋ธ์˜ ๊ตฌํ˜„์„ ์œ„ํ•ด OpenSees ver.2.4.3 (McKenna, 2011)์ด ์‚ฌ์šฉ๋˜์—ˆ๋‹ค. ๋˜ํ•œ, ์ง€๋ฐ˜์˜ ์—ฐํ™” ๊ฑฐ๋™์„ ํ•ด์„๋ชจ๋ธ์— ๋ฐ˜์˜ํ•˜๊ธฐ ์œ„ํ•ด OpenSees์—์„œ ์ œ๊ณต๋˜๋Š” hyperbolic ๋ชจ๋ธ์„ ์ˆ˜์ •ํ•˜์˜€๋‹ค. OpenSees๋Š” ํ”„๋กœ๊ทธ๋žจ ์ฝ”๋“œ๊ฐ€ ๊ณต๊ฐœ๋˜์–ด ์žˆ์–ด, ์ด๋ฅผ ๊ฐ€๊ณตํ•ด ์ƒˆ๋กœ์šด ์žฌ๋ฃŒ๋ชจ๋ธ์˜ ๊ตฌํ˜„์ด ๊ฐ€๋Šฅํ•˜๋‹ค.

Fig. 6.

Schemes of Experiment (Mashimo et al., 2002) and Numerical Model

Figure_KSCE_37_02_09_F6.jpg

์—ญํ•ด์„์— ํ™œ์šฉ๋œ ํ•ด์„ ๋ฐ์ดํ„ฐ๋Š” ์ฒœ๋‹จ์—์„œ์˜ ํ•˜์ค‘-๋ณ€์œ„ ์„ ๋„์ด๋ฉฐ, ์ƒ๊ด€๊ณ„์ˆ˜ 0.95 ์ด์ƒ์„ ์ถฉ์กฑํ•  ๋•Œ๊นŒ์ง€ ์ˆํฌ๋ฆฌํŠธ์˜ ์žฌ๋ฃŒ๋ฌผ์„ฑ์„ ๋ฐ”๊พธ์–ด๊ฐ€๋ฉฐ ์‹คํ—˜์— ์˜ํ•ด ์–ป์–ด์ง„ ํ•˜์ค‘-๋ณ€์œ„์„ ๋„์— ์ƒ์‘ํ•˜๋Š” ์žฌ๋ฃŒ๋ฌผ์„ฑ์„ ์ถ”์ •ํ•˜์˜€๋‹ค. ์ด๋ฅผ ํ†ตํ•ด ์ตœ์ข…์ ์œผ๋กœ Table 1๊ณผ ๊ฐ™์ด ์žฌ๋ฃŒ๋ฌผ์„ฑ์„ ๋„์ถœํ•˜์˜€์œผ๋ฉฐ, ์ด๋•Œ์˜ ํ•˜์ค‘-๋ณ€์œ„์„ ๋„๋ฅผ Fig. 7์— ๋‚˜ํƒ€๋‚ด์—ˆ๋‹ค.

Fig. 7.

Comparison with Experimental and Numerical Results (PIC21A7.gif)

Figure_KSCE_37_02_09_F7.jpg
Table 1. Input Variables of Shotcrete Table_KSCE_37_02_09_T1.jpg

4. ๊ฐ•์ง€๋ณด-์ˆํฌ๋ฆฌํŠธ ํ•ฉ์„ฑ๋ถ€์žฌ์˜ ๋น„์„ ํ˜• ํ•ฉ์„ฑ๊ฑฐ๋™ ๋ถ„์„

์••์ถ•๋ ฅ๊ณผ ํœจ ๋ชจ๋ฉ˜ํŠธ๋ฅผ ๋™์‹œ์— ๋ฐ›๋Š” ๊ฐ•์ง€๋ณด-์ˆํฌ๋ฆฌํŠธ ๋ผ์ด๋‹์˜ ํ•˜์ค‘์ง€์ง€์„ฑ๋Šฅ, ๋‹จ๋ฉด๋ ฅ, ์ง€๋ฐ˜-๊ตฌ์กฐ๋ฌผ ์ƒํ˜ธ์ž‘์šฉ์„ ๋ถ„์„ํ•˜๊ธฐ ์œ„ํ•ด ์ถ”๊ฐ€๋กœ ์œ ํ•œ์š”์†Œ๋ชจ๋ธ์„ ์ƒ์„ฑํ•˜์˜€๋‹ค. ์—ญํ•ด์„์— ์‚ฌ์šฉ๋œ ๋ชจ๋ธ์„ ์ˆ˜์ •ํ•˜์—ฌ Fig. 8๊ณผ ๊ฐ™์ด ํ•ด์„ ๋ชจ๋ธ์„ ์ƒ์„ฑํ•˜์˜€๋‹ค. ์ ์šฉํ•˜์ค‘์€ ์—ฐ์ง ๋ฐ ์ˆ˜ํ‰ํ† ์••์ด๋ฉฐ, ํ† ์••๊ณ„์ˆ˜ 0.5๋ฅผ ์ ์šฉํ•ด ์ˆ˜ํ‰ํ† ์••์ด ์—ฐ์งํ† ์••์— ์˜์กด์ ์œผ๋กœ ๊ฒฐ์ •๋˜๋„๋ก ํ•˜์˜€๋‹ค. ์ธก๋ฒฝ๋ถ€ ๊ฑฐ๋™์„ ๋ชจ์‚ฌํ•˜๊ธฐ ์œ„ํ•ด ๋ชจ๋ธ ์–‘๋‹จ์€ ์ˆ˜์ง ๋ณ€์œ„์™€ ํšŒ์ „ ๋ณ€์œ„๊ฐ€ ๊ตฌ์†๋˜๋„๋ก ๊ฒฝ๊ณ„์กฐ๊ฑด์„ ์„ค์ •ํ•˜์˜€๋‹ค(horizontally clamped roller). ๋˜ํ•œ, ์ฃผ๋ณ€ ์ง€๋ฐ˜๊ณผ์˜ ์ƒํ˜ธ์ž‘์šฉ์„ ๋ชจ์‚ฌํ•˜๊ธฐ ์œ„ํ•ด ์ง€๋ฐ˜์Šคํ”„๋ง์„ ํ•ด์„๋ชจ๋ธ์— ํฌํ•จ์‹œ์ผฐ๋‹ค. ๋‹ค๋งŒ, ์ฒœ๋‹จ ์ฃผ๋ณ€ ์ง€๋ฐ˜์€ ์ด์™„๋˜์–ด ํ•˜์ค‘์„ ์ง€์ง€ํ•  ์ˆ˜ ์—†๋‹ค๊ณ  ๊ณ ๋ คํ•˜์—ฌ ํ•ด๋‹น ์˜์—ญ์—๋Š” ์ง€๋ฐ˜ ์Šคํ”„๋ง์„ ์„ค์น˜ํ•˜์ง€ ์•Š์•˜๋‹ค. ํ•ด์„๋ชจ๋ธ์ด ์ตœ๋Œ€ํ•˜์ค‘ ์ดํ›„์˜ ๊ฑฐ๋™๊นŒ์ง€ ์˜ˆ์ธกํ•  ์ˆ˜ ์žˆ๋„๋ก ํ˜ธ์žฅ๋ฒ•(arc length method)์ด ์ ์šฉ๋˜์—ˆ์œผ๋ฉฐ, ์ด๋ฅผ ํ†ตํ•ด ์ ˆ์ ๋ณ€์œ„ ๋ฐ ์—ฐ์งํ† ์••์˜ ํฌ๊ธฐ๊ฐ€ ๊ฒฐ์ •๋˜๋„๋ก ํ•˜์˜€๋‹ค.

๋ถ€์žฌ ๋‹จ๋ฉด์˜ ํญ๊ณผ ๋‘๊ป˜๋Š” ๊ฐ๊ฐ 1000 mm, 300 mm์ด๋ฉฐ, NATM๊ณผ NMT์—์„œ ์ฃผ๋กœ ์‚ฌ์šฉ๋˜๊ณ  ์žˆ๋Š” H150ร—150ร—10ร—7 ํ˜•๊ฐ•๊ณผ D19 ์ฒ ๊ทผ(๋‹จ์ฒ ๊ทผ, ๋ณต์ฒ ๊ทผ)์ด ๊ฐ•์ง€๋ณด๋กœ์จ ์ ์šฉ๋˜์—ˆ๋‹ค. ํ•ฉ์„ฑ๋‹จ๋ฉด์— ๋Œ€ํ•œ ํ™”์ด๋ฒ„ ๋‹จ๋ฉด์„ Fig. 9์— ๋‚˜ํƒ€๋‚ด์—ˆ์œผ๋ฉฐ, ์ˆํฌ๋ฆฌํŠธ, ๊ฐ•์žฌ, ๊ทธ๋ฆฌ๊ณ  ์ง€๋ฐ˜์— ์ ์šฉ๋œ ์žฌ๋ฃŒ๋ฌผ์„ฑ์€ ๊ฐ๊ฐ Tables 1~3์— ์ œ์‹œ๋œ ๋ฐ”์™€ ๊ฐ™๋‹ค. ์—ฌ๊ธฐ์„œ Table 3์— ์ œ์‹œ๋œ ๊ฐ’๋“ค์€ 5๋“ฑ๊ธ‰ ์•”๋ฐ˜(PIC2225.gif: 200 MPa, PIC2283.gif: 20 kPa, and PIC22C3.gif: 30ยฐ)์— ๋Œ€ํ•œ ์žฌ๋ฃŒ๋ฌผ์„ฑ์— ์ƒ์‘ํ•œ๋‹ค.

Fig. 8.

Finite Element Model for Analyzing the Composite Behaviors of Primary Lining

Figure_KSCE_37_02_09_F8.jpg
Fig. 9.

Fiber Sections

Figure_KSCE_37_02_09_F9.jpg
Table 2. Constitutive Model and Parameters for Steel Supports Table_KSCE_37_02_09_T2.jpg
Table 3. Parameters of Modified Hyperbolic Model for Ground Table_KSCE_37_02_09_T3.jpg

4.1 ๊ฐ•์ง€๋ณด-์ˆํฌ๋ฆฌํŠธ ํ•ฉ์„ฑ๋ถ€์žฌ์˜ ํ•˜์ค‘-๋ณ€์œ„ ์‘๋‹ต ๋ฐ ๋‹จ๋ฉด๋ ฅ ๋ณ€ํ™”

๊ฐ•์ง€๋ณด ์œ ํ˜•๋ณ„ ํ•ฉ์„ฑ๋ถ€์žฌ์˜ ๊ฑฐ๋™์„ Figs. 10 and 11์— ๋‚˜ํƒ€๋‚ด์—ˆ๋‹ค. ๊ฐ๊ฐ์€ ์—ฐ์งํ† ์•• ๋ณ€ํ™”์— ๋”ฐ๋ฅธ ์ฒœ๋‹จ๋ณ€์œ„ ๋ณ€ํ™”์™€ ๊ฐ ์ ˆ์ ์—์„œ์˜ ํœจ๋ชจ๋ฉ˜ํŠธ ๋ฐ ์ถ•๋ ฅ์„ ๋„์‹œํ•œ ๊ฒƒ์ด๋‹ค. Fig. 10์—์„œ ๊ฐ•์ง€๋ณด ์œ ํ˜•์— ๊ด€๊ณ„์—†์ด ์ดˆ๊ธฐ ํ•˜์ค‘-๋ณ€์œ„ ๊ตฌ๊ฐ„์˜ ๋ผ์ด๋‹์˜ ๊ฐ•์„ฑ์€ ๊ฑฐ์˜ ๋™์ผํ•˜๊ฒŒ ์–ป์–ด์ง„๋‹ค. ์ด๋Š” ๋‚ฎ์€ ํ•˜์ค‘ ์ˆ˜์ค€์—์„œ ํœจ ๋ณด๋‹ค ์ถ•๋ ฅ์— ์˜ํ•ด ํ•ฉ์„ฑ๋ถ€์žฌ์˜ ์ €ํ•ญ์ด ๋ฐœํ˜„๋˜์–ด, ๋‹จ๋ฉด ๋‚ด ๋ฉด์ ๋น„๊ฐ€ ์ž‘์€ ๊ฐ•์žฌ์˜ ์ง€์ง€ํšจ๊ณผ๋Š” ์‚ฌ์‹ค์ƒ ๋ฌด์‹œ๋  ์ˆ˜ ์žˆ์Œ์„ ๋ณด์—ฌ์ฃผ๋Š” ๊ฒƒ์ด๋‹ค. ๊ทธ๋Ÿฌ๋‚˜ ํ•˜์ค‘์ด ์ฆ๋Œ€๋จ์— ๋”ฐ๋ผ, ์ˆํฌ๋ฆฌํŠธ์˜ ์ธ์žฅ์‘๋ ฅ์ด ์ธ์žฅ๊ฐ•๋„์— ์ด๋ฅด๊ฒŒ ๋˜๋ฉด์„œ, ํœจ ๊ฑฐ๋™์ด ์ง€๋ฐฐ์ ์ด๋˜๊ณ  ๊ฐ•์žฌ์— ์˜ํ•œ ์ง€์ง€ํšจ๊ณผ๊ฐ€ ๊ฐ€์‹œ์ ์œผ๋กœ ๋‚˜ํƒ€๋‚˜๊ฒŒ ๋œ๋‹ค. ์•„์น˜ํ˜•์ƒ์œผ๋กœ ์ธํ•ด ๋ถ€์žฌ ์ „ ์˜์—ญ์— ๊ฑธ์ณ ์ •, ๋ถ€๋ชจ๋ฉ˜ํŠธ๊ฐ€ ๋ฐœ์ƒํ•˜๊ฒŒ ๋˜๋ฏ€๋กœ, ๊ทธ ๊ฒฐ๊ณผ ๋ฌด๋ณด๊ฐ• ๋ฐ ๋‹จ์ฒ ๊ทผ ๋‹จ๋ฉด์€ ๋ณต์ฒ ๊ทผ ๋ฐ Hํ˜•๊ฐ• ๋ณด๊ฐ• ๋‹จ๋ฉด์— ๋น„ํ•ด ๋‚ฎ์€ ์ตœ๋Œ€ ์ง€์ง€๋ ฅ์„ ๋ณด์ด๊ณ  ์ ์ฐจ ํ•˜์ค‘์ง€์ง€๋ ฅ์„ ์ƒ์‹คํ•˜๊ฒŒ ๋œ๋‹ค.

Fig. 10.

Load-Displacement Curves

Figure_KSCE_37_02_09_F10.jpg
Fig. 11.

Bending Moment and Axial Force Diagrams

Figure_KSCE_37_02_09_F11.jpg

Fig. 12๋Š” ์ตœ๋Œ€ ํœจ ๋ชจ๋ฉ˜ํŠธ ๋ฐ ์ถ•๋ ฅ์ด ๋ฐœ์ƒ๋œ ์œ„์น˜์—์„œ์˜ ๊ฐ•์žฌ ํ™”์ด๋ฒ„์˜ ์‘๋ ฅ์ถ”์ด๋ฅผ ๋‚˜ํƒ€๋‚ธ ๊ฒƒ์ด๋‹ค. ์ตœ๋Œ€ํ•˜์ค‘ ์ดํ›„ ๊ฐ•์žฌ ๋ณด๊ฐ•๋œ ์ˆํฌ๋ฆฌํŠธ์˜ ํ•˜์ค‘-๋ณ€์œ„์„ ๋„๋Š” ๋ชจ๋‘ ๋‹จ์ฒ ๊ทผ ๋ณด๊ฐ•๋œ ๋ถ€์žฌ์˜ ์ž”๋ฅ˜ ํ•˜์ค‘ 150 kN/m๋กœ ์ˆ˜๋ ดํ•˜๊ฒŒ ๋˜๋Š”๋ฐ, ์ด๋Š” Fig. 12์˜ ๊ฐ•์žฌ์˜ ์‘๋ ฅ์ถ”์ด๋ฅผ ํ†ตํ•ด ๋‹ค์Œ๊ณผ ๊ฐ™์ด ์„ค๋ช…ํ•  ์ˆ˜ ์žˆ๋‹ค. ๊ฐ•์žฌ์˜ ํ•ญ๋ณต์€ ์ธก๋ฒฝ๋ถ€์—์„œ ๋จผ์ € ๋ฐœ์ƒํ•˜๊ณ , ์ดํ›„ ํ•˜์ค‘ ์ฆ๊ฐ€์— ๋Œ€ํ•ด ๋ผ์ด๋‹์€ ์ธก๋ฒฝ์— ์ธ์ ‘ํ•œ ๋ถ€๋ถ„๊ณผ ์ฒœ๋‹จ๋ถ€๋กœ ํ•˜์ค‘์ด ์ „์ด๋˜๋ฉด์„œ ์ €ํ•ญํ•˜๊ฒŒ ๋œ๋‹ค. ๊ทธ๋ฆฌ๊ณ  ์ตœ๋Œ€ํ•˜์ค‘ ์ดํ›„ ์ถ”๊ฐ€์ ์ธ ๋ณ€ํ˜•์— ์ €ํ•ญํ•˜๊ธฐ ์œ„ํ•ด ์ˆํฌ๋ฆฌํŠธ๋Š” ์—ฐํ™”๋˜๋ฉด์„œ ์‘๋ ฅ ์ˆ˜์ค€์ด ๊ฐ์†Œํ•œ๋‹ค. ๊ทธ ๊ฒฐ๊ณผ ์ „์ฒด ์ง€์ง€๋ ฅ์€ ๊ฐ•์žฌ์˜ ํœจ ์ €ํ•ญ๋ ฅ์— ์˜ํ•ด ๊ฒฐ์ •๋˜๋Š”๋ฐ, ์ตœ๋Œ€ํ•˜์ค‘ ์ดํ›„ ๋ณ€ํ˜•์ด ์ฆ๋Œ€๋จ์— ๋”ฐ๋ผ ์ • ๋ชจ๋ฉ˜ํŠธ ์ž‘์šฉ ์˜์—ญ์ด ์ง€๋ฐฐ์ ์ด ๋œ๋‹ค(Fig. 11). ๋”ฐ๋ผ์„œ ๋‹จ๋ฉด ํ•˜๋‹จ์— ์œ„์น˜ํ•œ ๊ฐ•์žฌ๊ฐ€ ํ•ญ๋ณต๋˜๋ฉด์„œ ์ถ”๊ฐ€์ ์ธ ํ•˜์ค‘์ง€์ง€๋ ฅ์€ ๋” ์ด์ƒ ๋ฐœํ˜„๋˜์ง€ ๋ชปํ•˜๊ธฐ ๋•Œ๋ฌธ์— ๋‹จ์ฒ ๊ทผ ๋‹จ๋ฉด์€ ๊ฐ€์žฅ ๋‚ฎ์€ ํ•˜์ค‘์ง€์ง€๋ ฅ์„ ๊ฐ€์ง€๊ฒŒ ๋œ๋‹ค. ๋ณต์ฒ ๊ทผ๊ณผ Hํ˜•๊ฐ• ๋‹จ๋ฉด์€ ์ƒ๋‹จ์˜ ๊ฐ•์žฌ์˜ ์ถ”๊ฐ€์ ์ธ ์ €ํ•ญ์ด ๊ฐ€๋Šฅํ•˜๋ฏ€๋กœ, ์ค‘๋ฆฝ์ถ•์ด ์ด๋™์— ์˜ํ•ด ์ถ”๊ฐ€ ์ง€์ง€๋ ฅ์„ ํ™•๋ณดํ•  ์ˆ˜ ์žˆ๋‹ค.

Fig. 12.

Stress History of Steel Supports

Figure_KSCE_37_02_09_F12.jpg

4.2 ๊ฐ• ์ง€๋ณด๋Ÿ‰ ์ฆ๊ฐ€์— ๋”ฐ๋ฅธ ํ•˜์ค‘์ง€์ง€์„ฑ๋Šฅ ๋ถ„์„

ํ•ฉ์„ฑ ๋ผ์ด๋‹์˜ ๊ฐ•์žฌ๋Ÿ‰ ๋ณ€ํ™”์— ๋”ฐ๋ฅธ ์ง€์ง€์„ฑ๋Šฅ ๋ณ€ํ™”๋ฅผ ๊ฒ€ํ† ํ•˜์˜€๋‹ค. ๋ณด๊ฐ• ๋‹จ๋ฉด ์œ ํ˜• ๋ฐ ๊ฐ•์žฌ๋Ÿ‰์„ ๋‹ฌ๋ฆฌํ•˜์—ฌ ์—ฐ์งํ† ์••-์ฒœ๋‹จ๋ณ€์œ„ ์„ ๋„๋ฅผ ๋„์ถœํ•˜๊ณ , ์ด๋กœ๋ถ€ํ„ฐ ๊ฐ ์„ ๋„์˜ ์ตœ๋Œ€ํ•˜์ค‘ ๋ฐ ์ž”๋ฅ˜ํ•˜์ค‘์„ ์ •๋ฆฌํ•ด Tables 4~6์— ๋‚˜ํƒ€๋‚ด์—ˆ๋‹ค. ๋‹จ์ฒ ๊ทผ ๋‹จ๋ฉด์˜ ๊ฒฝ์šฐ ์ฒ ๊ทผ๋Ÿ‰์ด ์ฆ๊ฐ€ํ•˜์—ฌ๋„ ์ตœ๋Œ€ํ•˜์ค‘์˜ ๋ณ€ํ™”๊ฐ€ ๋‚˜ํƒ€๋‚˜์ง€ ์•Š์•˜๊ณ , ์ตœ๋Œ€ํ•˜์ค‘ ์ดํ›„์˜ ์ž”๋ฅ˜ ์ง€์ง€๋ ฅ์˜ ์ฆ๊ฐ€๋งŒ ๊ด€์ฐฐ๋˜์—ˆ๋‹ค. ์ตœ๋Œ€ํ•˜์ค‘ ์ดํ›„ ๋ชจ๋ฉ˜ํŠธ๊ฐ€ ์ „์ฒด ๋ถ€์žฌ ๊ฑฐ๋™์— ๋Œ€ํ•ด ์ง€๋ฐฐ์ ์ด ๋˜๊ณ  ์ˆํฌ๋ฆฌํŠธ์— ์˜ํ•ด์„œ๋งŒ ๋ถ€ ๋ชจ๋ฉ˜ํŠธ๊ฐ€ ์ €ํ•ญ๋˜๋ฏ€๋กœ, ํ•ด์„๊ฒฐ๊ณผ์ฒ˜๋Ÿผ ๋‹จ์ฒ ๊ทผ์˜ ์ง€๋ณดํšจ๊ณผ๊ฐ€ ์ตœ๋Œ€ํ•˜์ค‘์˜ ์ฆ๊ฐ€์—†์ด ์ตœ๋Œ€ํ•˜์ค‘ ์ดํ›„์— ๋‚˜ํƒ€๋‚˜๋Š” ๊ฒƒ์€ ํƒ€๋‹นํ•˜๋‹ค๊ณ  ํŒ๋‹จ๋œ๋‹ค. ํ•œํŽธ ๋ถ€ ๋ชจ๋ฉ˜ํŠธ์— ์ €ํ•ญ์ด ๊ฐ€๋Šฅํ•œ ๋ณต์ฒ ๊ทผ๊ณผ Hํ˜•๊ฐ• ๋‹จ๋ฉด์€ ์ตœ๋Œ€ํ•˜์ค‘์ด ์ฆ๊ฐ€๋˜์—ˆ๋‹ค. ํŠนํžˆ, ๋ณต์ฒ ๊ทผ ๋‹จ๋ฉด์€ ๊ฐ•์žฌ๋Ÿ‰์ด ์ฆ๊ฐ€๋จ์— ๋”ฐ๋ผ ์ž”๋ฅ˜ ์ง€์ง€๋ ฅ์ด ํฌ๊ฒŒ ํ–ฅ์ƒ๋˜์—ˆ๋‹ค. ๊ทธ๋Ÿฌ๋‚˜ ์ตœ๋Œ€ํ•˜์ค‘ ๋ฐ ์ž”๋ฅ˜์ง€์ง€๋ ฅ์ด ๊ฐ•์žฌ ์ฆ๊ฐ€๋Ÿ‰์— ๋Œ€ํ•ด ์„ ํ˜•์ ์œผ๋กœ ๋น„๋ก€ํ•˜์ง€๋Š” ์•Š์•˜๋‹ค. ์ด๋Š” ๋‹ค๋Ÿ‰์˜ ๊ฐ•์žฌ ์‚ฌ์šฉ์ด ํšจ๊ณผ์ ์ธ ํ•ฉ์„ฑ ๋ผ์ด๋‹์˜ ์ตœ๋Œ€ ๋ฐ ์ž”๋ฅ˜์ง€์ง€๋ ฅ ํ–ฅ์ƒ์œผ๋กœ ์ด์–ด์ง€์ง€ ์•Š์Œ์„ ์˜๋ฏธํ•œ๋‹ค.

Table 4. Peak and Residual Load Capacities of Shotcrete Linings:Single Reinforcement Rebar Table_KSCE_37_02_09_T4.jpg
Table 5. Peak and Residual Load Capacities of Shotcrete Linings:Double Reinforcement Rebar Table_KSCE_37_02_09_T5.jpg
Table 6. Peak and Residual Load Capacities of Shotcrete Linings:H-shaped Beam Table_KSCE_37_02_09_T6.jpg

4.3 ์ง€๋ฐ˜ ๊ฐ•์„ฑ์ด ํ„ฐ๋„ ๊ตฌ์กฐ๋ฌผ์˜ ์ตœ๋Œ€ ํ•˜์ค‘์ง€์ง€๋ ฅ์— ๋ฏธ์น˜๋Š” ์˜ํ–ฅ

์ดˆ๊ธฐ ์ง€๋ฐ˜๊ฐ•์„ฑ์ด ํ„ฐ๋„ ๊ตฌ์กฐ๋ฌผ์˜ ํ•˜์ค‘์ง€์ง€์„ฑ๋Šฅ์— ๋ฏธ์น˜๋Š” ์˜ํ–ฅ์„ ๋ถ„์„ํ•˜์—ฌ Fig. 13์— ๋‚˜ํƒ€๋‚ด์—ˆ๋‹ค. ์—ฌ๊ธฐ์„œ ์ง€๋ฐ˜๊ฐ•์„ฑ๊ณผ ์ตœ๋Œ€ ํ•˜์ค‘์ง€์ง€๋ ฅ์€ ๊ฐ๊ฐ ์ดˆ๊ธฐ ํƒ„์„ฑ๊ณ„์ˆ˜๊ฐ€ 200 MPa์ธ ์ง€๋ฐ˜๊ณผ ๋ฌด๋ณด๊ฐ• ๋ผ์ด๋‹์˜ ์ตœ๋Œ€ ํ•˜์ค‘์ง€์ง€๋ ฅ์„ ์ด์šฉํ•ด ์ •๊ทœํ™” ํ•˜์˜€์œผ๋ฉฐ, PIC22F3.gif๋Š” ์ดˆ๊ธฐ ์Šคํ”„๋ง ๊ฐ•์„ฑ, PIC2303.gif๋Š” ํƒ„์„ฑ๊ณ„์ˆ˜ 200 MPa ์กฐ๊ฑด์˜ ์ง€๋ฐ˜์— ์ƒ์‘ํ•˜๋Š” ์ดˆ๊ธฐ ์Šคํ”„๋ง ๊ฐ•์„ฑ, PIC2324.gif๋Š” ๊ฐ•์žฌ ๋ณด๊ฐ•๋œ ์ˆํฌ๋ฆฌํŠธ ๋ผ์ด๋‹์˜ ์ตœ๋Œ€ ์ง€์ง€๋ ฅ, PIC2344.gif๋Š” ๋ฌด๋ณด๊ฐ• ์ˆํฌ๋ฆฌํŠธ ๋ผ์ด๋‹์˜ ์ตœ๋Œ€ ์ง€์ง€๋ ฅ์ด๋‹ค. ์ดˆ๊ธฐ ์ง€๋ฐ˜๊ฐ•์„ฑ์ด ์ฆ๊ฐ€๋จ์— ๋”ฐ๋ผ ๊ฐ•์žฌ๊ฐ€ ํ•ฉ์„ฑ ์ง€๋ณด์˜ ์ง€์ง€๋ ฅ์— ๋ฏธ์น˜๋Š” ์˜ํ–ฅ์ด ๊ฐ์†Œ๋˜์—ˆ์œผ๋ฉฐ, ํ•ฉ์„ฑ ์ง€๋ณด์˜ ์ตœ๋Œ€ ํ•˜์ค‘์ง€์ง€๋ ฅ์€ ์ง€๋ฐ˜๊ฐ•์„ฑ์ด ์ฆ๊ฐ€๋จ์— ๋”ฐ๋ผ ์ผ์ •ํ•œ ๊ฐ’์œผ๋กœ ์ˆ˜๋ ดํ•˜์˜€๋‹ค. ํ„ฐ๋„ ์‹œ์Šคํ…œ์— ์ž‘์šฉํ•˜๋Š” ์ „์ฒด ํ•˜์ค‘์€ ์ง€๋ฐ˜๊ณผ ๊ตฌ์กฐ์ฒด์˜ ๊ฐ•์„ฑ์— ๋”ฐ๋ผ ๋ถ„๋ฐฐ๋˜๋Š”๋ฐ, ์ง€๋ฐ˜๊ฐ•์„ฑ์ด ๋†’์•„์ง์— ๋”ฐ๋ผ ์™ธ๋ ฅ์˜ ์ƒ๋‹น ๋ถ€๋ถ„์„ ๊ตฌ์กฐ์ฒด ์ฃผ๋ณ€์˜ ์ง€๋ฐ˜์ด ๋ถ„๋‹ดํ•˜๊ฒŒ ๋˜๊ธฐ ๋•Œ๋ฌธ์— ์ด๋Ÿฌํ•œ ๊ฒฐ๊ณผ๊ฐ€ ๋‚˜ํƒ€๋‚˜๊ฒŒ ๋˜์—ˆ๋‹ค๊ณ  ํŒ๋‹จ๋œ๋‹ค.

Fig. 13.

Effect of the Initial Ground Stiffness

Figure_KSCE_37_02_09_F13.jpg

5. ๊ฒฐ ๋ก 

๋ณธ ์—ฐ๊ตฌ์—์„œ๋Š” ์ˆ˜์น˜ํ•ด์„์„ ํ†ตํ•ด ๊ฐ•์žฌ ๋ณด๊ฐ•๋œ ์ˆํฌ๋ฆฌํŠธ ๋ผ์ด๋‹์˜ ๋น„์„ ํ˜• ํ•ฉ์„ฑ๊ฑฐ๋™์„ ์ˆ˜์น˜์ ์œผ๋กœ ๋ถ„์„ํ•˜์˜€๋‹ค. ์ง€๋ณด์žฌ์˜ ๋น„์„ ํ˜• ํ•ฉ์„ฑ๊ฑฐ๋™์„ ๊ตฌํ˜„ํ•˜๊ธฐ ์œ„ํ•ด ํ™”์ด๋ฒ„ ๋‹จ๋ฉด ์š”์†Œ๋ฅผ ์‚ฌ์šฉํ•˜์˜€์œผ๋ฉฐ, ์ง€๋ฐ˜์˜ ์—ฐํ™” ๊ฑฐ๋™์„ ๊ณ ๋ คํ•œ ์ˆ˜์ •๋œ hyperbolic ๋ชจ๋ธ์„ ๊ฐœ๋ฐœํ•ด ํ•ด์„๋ชจ๋ธ์— ์ ์šฉํ•˜์˜€๋‹ค. ์ œ์‹œ๋œ ํ•ด์„๋ชจ๋ธ์€ ์ถ•๋ ฅ๊ณผ ๋ชจ๋ฉ˜ํŠธ๊ฐ€ ๋™์‹œ์— ๋ฐœ์ƒํ•˜๋Š” ์‹ค๊ทœ๋ชจ์ธ ์•„์น˜ํ˜• ๊ตฌ์กฐ๋ฌผ์˜ ํ•˜์ค‘-๋ณ€์œ„ ์‘๋‹ต์„ ์žฌํ˜„ํ•ด ๋ƒˆ์œผ๋ฉฐ, ์—ฌ๋Ÿฌ ๊ฐ•์ง€๋ณด ์œ ํ˜•์— ๋”ฐ๋ฅธ ์ˆํฌ๋ฆฌํŠธ-๊ฐ• ์ง€๋ณด ํ•ฉ์„ฑ ๋ผ์ด๋‹์˜ ํ•˜์ค‘์„ฑ๋Šฅ์„ ํ‰๊ฐ€ํ•˜๋Š”๋ฐ ํ™œ์šฉ๋˜์—ˆ๋‹ค. ๋ณธ ์—ฐ๊ตฌ์˜ ๊ฒฐ๊ณผ๋กœ๋ถ€ํ„ฐ ๋‹ค์Œ๊ณผ ๊ฐ™์€ ๊ฒฐ๋ก ์„ ๋„์ถœํ•˜์˜€๋‹ค.

(1)๋‹จ์ฒ ๊ทผ, ๋ณต์ฒ ๊ทผ, Hํ˜•๊ฐ•์ด ๋ณด๊ฐ•๋œ ์ˆํฌ๋ฆฌํŠธ ๋ผ์ด๋‹์˜ ์ตœ๋Œ€ ๋ฐ ์ž”๋ฅ˜ ์ง€์ง€๋ ฅ์ด ๊ฒ€ํ† ๋˜์—ˆ๋‹ค. ์ดˆ๊ธฐ ํ•˜์ค‘-๋ณ€์œ„ ๋ฐœ์ƒ ๊ตฌ๊ฐ„์—์„œ ํ•ฉ์„ฑ ์ง€๋ณด๋Š” ๊ฐ•์ง€๋ณด ์œ ํ˜•์— ์ƒ๊ด€์—†์ด ์œ ์‚ฌํ•œ ๊ฐ•์„ฑ์„ ๋‚˜ํƒ€๋‚ธ๋‹ค. ๊ทธ๋Ÿฌ๋‚˜ ์ตœ๋Œ€ ๋ฐ ์ž”๋ฅ˜ ์ง€์ง€๋ ฅ์€ ๊ฐ•์ง€๋ณด ์œ ๋ฌด ๋ฐ ๊ฐ•์ง€๋ณด ์œ ํ˜•์— ๋”ฐ๋ผ ๋ณ€ํ•˜๊ฒŒ ๋˜๋ฉฐ, ๋ณต์ฒ ๊ทผ ๋ฐ Hํ˜•๊ฐ• ๋ณด๊ฐ• ๋‹จ๋ฉด์˜ ์ง€๋ณดํšจ๊ณผ๊ฐ€ ํผ์„ ํ™•์ธํ•  ์ˆ˜ ์žˆ์—ˆ๋‹ค. ๋‘ ๋‹จ๋ฉด์€ ์ฃผ์–ด์ง„ ํ•˜์ค‘ ๋ฐ ๊ธฐํ•˜์กฐ๊ฑด์—์„œ ๋ฌด๋ณด๊ฐ• ๋‹จ๋ฉด์— ๋น„ํ•ด ์•ฝ 10~15%์˜ ์ตœ๋Œ€ ์ง€์ง€๋ ฅ ์ฆ๊ฐ€๋ฅผ ๋ณด์˜€๋‹ค. ๋ฐ˜๋ฉด, ๋‹จ์ฒ ๊ทผ ๋ณด๊ฐ• ๋‹จ๋ฉด์€ ํ„ฐ๋„ ๋ผ์ด๋‹์—์„œ ๋ฐœ์ƒ๋˜๋Š” ์ธก๋ฒฝ๋ถ€ ๋ถ€ ๋ชจ๋ฉ˜ํŠธ์— ๋Œ€ํ•œ ์ €ํ•ญ๋ ฅ์ด ๋‚ฎ์•„ ๋‹ค๋ฅธ ๊ฐ•์žฌ ๋ณด๊ฐ• ๋‹จ๋ฉด์— ๋น„ํ•ด ๋‚ฎ์€ ์ตœ๋Œ€ ํ•˜์ค‘์ง€์ง€๋ ฅ์„ ๊ฐ€์ง€๋ฉฐ, ์ตœ๋Œ€ ํ•˜์ค‘์ง€์ง€๋ ฅ ๊ด€์ ์—์„œ๋Š” ์‚ฌ์‹ค์ƒ ์ง€๋ณดํšจ๊ณผ๊ฐ€ ์—†๋‹ค๊ณ  ํŒ๋‹จ๋œ๋‹ค. ๊ทธ๋Ÿฌ๋‚˜ ์ž”๋ฅ˜ ์ง€์ง€๋ ฅ์— ๋Œ€ํ•ด์„œ๋Š” ์ง€๋ณด ํšจ๊ณผ๊ฐ€ ๋‚˜ํƒ€๋‚˜๋Š” ๊ฒƒ์œผ๋กœ ํ™•์ธ๋˜์—ˆ๋‹ค.

(2)ํ„ฐ๋„ ๋ผ์ด๋‹์˜ ํœจ ๋ชจ๋ฉ˜ํŠธ๋Š” ์ˆํฌ๋ฆฌํŠธ๊ฐ€ ํ•ญ๋ณต๋จ์— ๋”ฐ๋ผ ์ • ๋ชจ๋ฉ˜ํŠธ ์˜์—ญ์ด ํ™•๋Œ€๋˜์—ˆ์œผ๋ฉฐ, ์ด๋Ÿฌํ•œ ๊ฒฝํ–ฅ์€ ๊ฐ• ์ง€๋ณด ์œ ๋ฌด ๋ฐ ์œ ํ˜•๊ณผ ๋ฌด๊ด€ํ•˜๊ฒŒ ๊ด€์ฐฐ๋˜์—ˆ๋‹ค. ์ด๋Š” ์ธก๋ฒฝ๋ถ€ ๋ถ€๋ชจ๋ฉ˜ํŠธ์— ์˜ํ•ด ํ„ฐ๋„ ๋ผ์ด๋‹์˜ ํ•ญ๋ณต์ด 1์ฐจ์ ์œผ๋กœ ๋ฐœ์ƒํ•˜๊ณ , ์ดํ›„ ์ฒœ๋‹จ ๋ฐ ์–ด๊นจ๋ถ€ ๋ผ์ด๋‹์ด ์ถ”๊ฐ€์ ์ธ ๋ณ€ํ˜• ์ฆ๊ฐ€์— ๋Œ€ํ•ด ์ €ํ•ญํ•ด์ฃผ๋Š” ํ•˜์ค‘ ์ „์ด ๋งค์ปค๋‹ˆ์ฆ˜์„ ๊ฐ€์ง€๊ธฐ ๋•Œ๋ฌธ์œผ๋กœ ํŒ๋‹จ๋œ๋‹ค. ์ถ•๋ ฅ์€ ์™ธ๋ ฅ์ด ์ฆ๊ฐ€๋จ์— ๋”ฐ๋ผ ์ฆ๊ฐ€ํ•˜๋‹ค๊ฐ€ ์ตœ๋Œ€ ์ง€์ง€๋ ฅ ๋ฐœ์ƒ ํ›„์— ๊ฐ์†Œํ•˜์˜€๋‹ค.

(3)๊ฐ•์žฌ๋Ÿ‰์˜ ์ฆ๊ฐ€๋Š” ํ•ฉ์„ฑ์ง€๋ณด์˜ ํ•˜์ค‘ ์ง€์ง€์„ฑ๋Šฅ์„ ๊ฐœ์„ ์‹œ์ผฐ๋‹ค. ๋‹จ์ฒ ๊ทผ ๋‹จ๋ฉด์˜ ๊ฒฝ์šฐ ์ฒ ๊ทผ ์ˆ˜๊ฐ€ ์ฆ๊ฐ€๋จ์— ๋”ฐ๋ผ ๊ฐ€์‹œ์ ์ธ ์ตœ๋Œ€ ์ง€์ง€๋ ฅ ์ฆ๊ฐ€๋กœ ๋‚˜ํƒ€๋‚˜์ง€ ์•Š์•˜์ง€๋งŒ, ์ž”๋ฅ˜ ์ง€์ง€๋ ฅ์ด ์ฆ๊ฐ€๋˜์—ˆ๋‹ค. ๋ณต์ฒ ๊ทผ ๋‹จ๋ฉด๊ณผ Hํ˜•๊ฐ• ๋‹จ๋ฉด์˜ ๊ฒฝ์šฐ ๊ฐ•์žฌ๋Ÿ‰์ด ์ฆ๊ฐ€๋จ์— ๋”ฐ๋ผ ์ตœ๋Œ€ ๋ฐ ์ž”๋ฅ˜ ์ง€์ง€๋ ฅ์ด ๋ชจ๋‘ ํ–ฅ์ƒ๋˜์—ˆ์œผ๋ฉฐ, ํŠนํžˆ ๋ณต์ฒ ๊ทผ ๋‹จ๋ฉด์˜ ์ž”๋ฅ˜ ์ง€์ง€๋ ฅ ํ–ฅ์ƒ์ด ํฌ๊ฒŒ ์ฆ๋Œ€๋˜๋Š” ๊ฒƒ์„ ํ™•์ธํ•˜์˜€๋‹ค. ๊ทธ๋Ÿฌ๋‚˜ ๊ฐ•์žฌ๋Ÿ‰์˜ ์ฆ๊ฐ€๊ฐ€ ์ตœ๋Œ€ ๋ฐ ์ž”๋ฅ˜ ์ง€์ง€๋ ฅ์˜ ์„ ํ˜•์  ์ฆ๊ฐ€ ๊ด€๊ณ„๋ฅผ ๊ฐ–๋Š” ๊ฒƒ์€ ์•„๋‹ˆ๋ฏ€๋กœ, ์ดˆ๊ณผ์ ์ธ ๊ฐ•์žฌ ์‚ฌ์šฉ์€ ๋น„์šฉ ๋ฐ ์‹œ๊ณต ์ธก๋ฉด์—์„œ ์ ์ ˆํ•˜์ง€ ์•Š๋‹ค๊ณ  ํŒ๋‹จ๋œ๋‹ค. ๋˜ํ•œ, ํ•ฉ์„ฑ๋ผ์ด๋‹์˜ ์„ฑ๋Šฅ ํ–ฅ์ƒ๊ณผ ์‹œ๊ณต์  ์ธก๋ฉด์„ ๊ณ ๋ คํ–ˆ์„ ๋•Œ, ๋ณต์ฒ ๊ทผ ์œ ํ˜•์˜ ๊ฐ•์ง€๋ณด ํ™œ์šฉ์ด ๊ณ ๋ ค๋  ํ•„์š”๊ฐ€ ์žˆ๋‹ค.

Acknowledgements

๋ณธ ์—ฐ๊ตฌ๋Š” ํ•œ๊ตญ์—ฐ๊ตฌ์žฌ๋‹จ์˜ โ€˜์ง€๋ฐ˜-์ง€๋ณด์žฌ๊ฐ„ ์ƒํ˜ธ์ž‘์šฉ์„ ๊ณ ๋ คํ•œ ๋Œ€์‹ฌ๋„ NATMํ„ฐ๋„์˜ ์ตœ์ ์„ค๊ณ„โ€™์™€ ์‚ฐ์—…ํ†ต์ƒ์ž์›๋ถ€ ์—๋„ˆ์ง€๊ธฐ์ˆ ํ‰๊ฐ€์›์˜ โ€˜ํŒŒ๋ ฅ๋ฐœ์ „์˜ ๋ฐœ์ „ํšจ์œจ ํ–ฅ์ƒ์„ ์œ„ํ•œ ์—ฐ๊ทผํ•ด์šฉ ์ˆ˜ํ‰์ถ• ํšŒ์ „์˜ 3 kW๊ธ‰ ์›ํ†ตํ˜• ํŒŒ๋ ฅ๋ฐœ์ „ ์‹œ์Šคํ…œ ๊ฐœ๋ฐœ(20160708-001)โ€™์˜ ์žฌ์ •์  ์ง€์›์— ์˜ํ•ด ์ˆ˜ํ–‰๋˜์—ˆ์Šต๋‹ˆ๋‹ค. ์ด์— ๊ฐ์‚ฌ๋“œ๋ฆฝ๋‹ˆ๋‹ค.

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