4220026 pp. 19 31 A Study on Effect of Earth Pressure Reduction and the Silo Earth Pressure Retaining Wall by CLSM Backfill with Waste Foundry Sand of the ****** Cho, J ae- yun*lee, Kwan-ho**Cho, Yoon- ho*** A B S T RA CT T he recycling of w aste foundry sand(wfs ) and fly ash as by- products of industry is one of the urgent problem t o deal with. F or the recycling of these materials, CLSM (controlled low strength materials ) concept w as adopted. T his research has been done for last thr ee years. In this r esearch, couple of selected w aste foundry sand and fly ash w ere used as fine aggregate. Also, WFS modified by proper chemical liquid w as used for the comparison. T he main focus is to evaluate the silo earth pressure and the reduction effect due t o the use of CLSM instead of normal fine aggregate. Silo effect, which occurs at short distance betw een ret aining w all and backfill, w as not detected because the charact erization of CLSM is highly differ ent from that of normal aggregate. T herefore, the theory for earth pressure, like Rankine theory or Coulomb theory, should be car efully used for CLSM. T he reduction of earth pressur e for modified WFS is higher than the others. But, the final earth pr essure is conver ged at very sm all value, even though the r eduction effect depends on the curing time. K ey w ords : CL SM, f ly - ash, f lowable backf ill, lateral earth p ressure, was te f oundry sand. ( CLSM) 3., CLSM.,.. CLSM,.,,., CLSM,. :,,, * (cjy@dit.ac.kr / Tel. : 05 1-860- 3 116) ** (khlee @ks.ac.kr / Tel. : 05 1-620- 4756) *** (yhcho @ca u.ac.kr / Te l. : 02-820- 5336) 19
1. (flowable mortar), - (soil-cement slurry), 2 (self-leveling),, (self-compacting), (flowability),., (Abichou et al., 1998, Naik & Singh, 1997). CLSM. (, ). 3., 5,,,.,, 1. (Lee et al., 2001;, 2000). 3 (Silo Earth Pressure).,,, ( ) CLSM.. (backfill materials)., 2. 2.1.,, 20 14,, 5%.. CLSM (Controlled Low Strength Materials).. CLSM(flowable fill), (controlled strength fill),. 20
KS,,,.,.,., (, 2000 ;, 1992).. (,,, ) 3. Silo., CLSM (, 2000).. 1, 2.2,,,,,, 1545% (Bottum Ash), (Fly Ash)..,.,,,,,,., 18.3%..,,. 1. (1). V + d V + 2K V dz = V + B dz (1) B, = t an. (1), (2). 2 1 - exp { - 2K ( z / B ) } V = B 2K (2) 21
h (3). 4.1 h = K V B = B 2 [ 1 - ex p { - 2K ( h/ B )}] (3) KMarstonAnderson (1913) Rankine, Krynine(1945). K = h v = 1 - sin 2 1 + sin 2 (4), Handy(1985) K. (5). K = h v = 1.06 ( cos 2 + K a s in 2 ) (5) FrydmanKeissar (1987) K (6). - K = ( s in 2 + 1) (4 t an 2 - s in 2 + 1) (6) ( sin 2 + 1) 2 - ( 1 - s in 2 )(4 tan 2 - s in 2 + 1) (4 t an 2 - s in 2 + 1) CLSM,. 1Class F, 2.170. 2. KSL 5201 1. 1. ASTM (ASTM, 1994) N F C min SiO2+Al2O3 +Fe2O3 (%) 70.0 70.0 50.0 max SO3 (% ) 4.0 5.0 5.0 m ax Moisture content (%) 3.0 3.0 3.0 max Loss on ignition (% ) 10.0 6.0 6.0 m ax Na2 O (%) 1.5 1.5 1.5 L.O.I. : Loss On Ignition (%) 2. SiO2 Al2O3 Fe2O3 T io2 MnO 60.33 24.78 3.82 1.06 0.00 CaO MgO K2O Na2O P2O5 L.O.I 2.39 0.84 0.86 0.59 0.50 4.84 (%), Rankine 4.2. K a = ( 1 - s in ) (7) (Furane Sand), ( 1 + s in )., 4.. 22
, (, 1998). XRF(X-ray Refraction) 3, SiO2, Al2O3, Fe2O3 90%,,. 2, 4. (Furane Sand)2.459 2.684, 2.652.,. 3. XRF (: %) Sand SiO2 Al2O3 Fe2 O3 T io2 MnO Green 80.74 7.92 2.75 0.22 0.00 Furane 87.04 5.45 0.91 0.19 0.00 Sand CaO MgO K2 O Na2 O P2 O5 L.O.I. Green 0.71 0.48 2.27 1.43 0.02 3.46 Furane 0.19 0.04 2.67 0.66 0.01 2.85 Particle size (mm) 2. 4. D10 (mm ) 0.14 0.20 0.36 0.37 0.18 D3 0 (mm ) 0.21 0.34 0.61 0.46 0.27 D6 0 (mm ) 0.25 0.57 1.15 0.68 0.42 Cu 1.79 2.85 3.19 1.84 2.33 Cc 1.26 1.01 0.90 0.84 0.96 Poorly Gap Poorly Poorly Poorly 4.3 CLSM (The American Concrete Institute, 1994)CLSM,, 28 8.3 MPa. CLSM 28 1035 kpa, 550kPa (Bhat & Lovell, 1996 ; Horiuchi et al., 1992 ; Janardhanam et al., 1992 ; Smith, 1991). Nantung(1993), (, 2000). 5 (,, ),,,. 23
5. (%) 8.1 17.1 29.8 20.8 21.6 64.7 61.9 47.2 55.5 58.4 3.0 1.6 1.54 3.6 1.8 24.2 19.4 21.6 20.1 18.2 5. (a) 5.1 3, 100cm 52cm 50cm( ), data log. 4. (t = 50mm),,. 5, 5052(). (t = 7mm),...., 2LVDT (Linear Variable Differential Transformer)2 (, 2000). (b) 3. 50cm 14~ 18mm hinge 40cm LVDT #2 LVDT #1 #2 road cell potentiometer potentiometer #2 - + 52cm potentiometer #1 4. 24
(a) 52.0cm 4.5cm 10.0cm. (raining method),,.,. (, 2000 ; Lee et al. 2001)., 50% ( ),. 5 10.0cm 10.0cm 6. 6.1 10.0cm 5.5cm (b) 5. 6,, 7., 5.2 6., (,, ) (, 2000 ; Lee et al. 2001). 7. CLSM 50%, CLSM.. CLSM 6,,, 25
., 1-2,. CLSM,, CLSM,. 6, CLSM, CLSM.,,. (c) CLSM 6. (a) CLSM (a) CLSM (b) CLSM (b) CLSM (c) CLSM 7. 26
6.2 3-4., 6 CLSM, (, 2000).. CLSM, CLSM. (, 2000 ; Lee et al. 2001).,, CLSM,. CLSM., CLSM 50%. CLSM,. 6, CLSM (, ) 6. CLSM (g/cm 2 ). 8 CLSM 50-60%,. (, 2000, Lee et al., 2001). CLSM 7.,.,, CLSM CLSM 0.15 h 0.39 h 0.1 h - 4.5 cm 15.0 20.25 10.80 2.40 14.5 cm 35.26 31.82 30.10 12.04 24.5 cm 46.53 46.06 47.00 14.10 34.5 cm 68.04 62.58 67.64 13.35 44.5 cm 69.01 74.16 74.80 30.8 7. / CLSM (hr ) 0.15 0.39 0.10 - () 2331.7 2330.1 2311.1 735.7 18.77 (, ) 18.69 17.74 17.02 6.3 27
. CLSM CLSM,.,. 6,. CLSM1.1mm.,, CLSM1.0mm, CLSM0.75mm.,, 0.6mm CLSM.. CLSM.,., CLSM. 8. (mm) Peak 12h 1d 2d 3d 4d 5d 0 0.92 0.92 0.92 0.92 0.92 0.92 0.92 0 0 0 0 0 0 0 0 0 1.25 0.96 1.05 1.07 1.08 1.09 1.10 0 0.12 0.09 0.11 0.11 0.12 0.12 0.12 CLSM 0 0.74 0.59 0.64 0.65 0.65 0.65 0.65 0 1.03 0.42 0.55 0.55 0.55 0.55 0.55 0 1.02 0.49 0.50 0.55 0.53 0.53 0.53 0 1.12 1.01 0.99 0.99 0.99 0.99 0.98 9. (h:, d:) Peak 1h 12h 1d 1.5d 2.0d 1.25 1.10 0.75 CLSM 2.33 1.1 1.38 1.23 0.96 0.61 2.33 1.53 0.36 0.65 0.31 0.2 2.31 0.95 0.5 0.73 0.85 0.83 0.74 2.5d 3.0d 4d 5d 6d 7d 1.25 1.10 0.75 CLSM 0.5 0.42 0.33 0.24 0.14 0.07 0.2 0.22 0.24 0.27 0.24-0.82 0.8 0.78 0.72 0.66 0.58 0.74 6.4 6.5 10 9.,.,, 28
. CLSM,,..,. CLSM. 10. CLSM ( ) CLSM CLS M CLS M CLS M 4.5 cm 14.5 cm 24.5 cm 34.5 cm 44.5 cm 1 2.39 7.42 12.06 16.36 20.33 2 2.18 6.77 11.04 15.01 18.70 3 2.16 6.72 10.95 14.89 18.55 5 1.89 5.91 9.68 13.20 16.51 7 1.83 5.72 9.36 12.77 15.94-2.40 12.04 14.10 13.35 30.80 1 3.00 17.20 21.62 36.54 43.26 2 3.00 16.34 16.92 13.02 12.36 3 3.75 11.18 15.98 5.88 6.18 5 9.00 8.60 7.52 2.52 0.00 7 8.25 7.74 1.41 0.00 0.00 1 5.25 5.16 8.46 30.66 16.48 2 7.50 3.44 3.76 3.78 3.09 3 0.00 5.16 1.41 1.68 14.42 5 3.00 4.30 2.35 1.68 15.45 1 0.00 22.36 2.35 13.80 34.10 2 0.00 20.64 2.82 16.47 41.48 3 0.60 19.78 3.76 16.47 38.50 5 0.00 17.20 3.76 15.13 34.10., CLSM,. CLSM,,. 6.6 SEM 8CLSM,,. 7, CLSM. 3,,, CLSM,. 50%,.., (a) (b) (c) 8. SEM CLSM 29
7.. (1) (5) CLSM CLSM,. CLSM.., 50%, 25% (2) CLSM,, (6) CLSM 2-3 3..,,,.. (3) CSLM,,..,,.,,,. (4) CLSM (SEM)7 1. (1998),,, pp. 119., 2. (2000),,,,, pp. 179. 3.,, (2000), " 30
",, Vol. 16, No. 4, pp. 17-30 4. (1992),, KRC- 90H - J06 5. Abichou, T., Benson, C., and Edil, T. (1998), "Beneficial Reuse of F oundary S an ds in Construction of Hy draulic Barrier Lay ers", E nv ironm ental Geotechn ics R ep ort 98-2, Dept. of Civil and Environm ental Engin eering, Univ ersity of W iscon sin - M adison. 6. ACI Committee 229 (1994), "Controlled Low Strength Materials(CLSM)", Concrete International, July, pp. 55-64 7. AST M (1994), A nnual B ook of A S TM S tandards 8. Bhat, S. T., and Lov ell, C. W. (1996), " Us e of Coal Com bustion R es idues and W aste F oundry Sands in F lowable F ill", Joint Highw ay Research Project, F HW A / IN/ JHRP - 96/ 2, pp. 222. 9. Fry dm an, S. and Keissar, I. (1987), "E arth Pressure on Retaining W alls near Rock F aces", J GE, A S CE, Vol. 113, N o. 6, pp. 586-599 10. Han dy, R. L. (1985), "T h e Arch in Soil Arching ", J GE, A S CE, V ol. 111, N o. 3, pp. 302-318 11. Horiuchi, S., T aketsuka, M., Odaw ara, T., and Kaw asaki, H. (1992), "Fly - ash Slurry Island: I. T heoretical and Experimental Investig ations", J ournal of M aterials in Civ il E ng in eering, V ol. 4, N o. 2, M ay, pp. 117133 12. Jan ardh anam, R., Burn s, F., and P eindl, R. D. (1992), "Mix Design for Flow able Ffly - ash Backfill M aterial", J ournal of M aterials in Civ il E ng in eering, A S CE, V ol. 4, N o.3, August, pp. 252263 13. Krynine, D. P. (1945), "Stability and Stiffness Celular Cofferdam s", T erzaghi T ransaction, A S CE, Vol. 110, pp. 1175-1178. 14. Lee, K., Cho, J., Rodrig o, S. an d Lee, I (2001), "T h e Sm all- Scale Retaining W all T est of W aste F oun dry Sand Mixture as Flow able F ill", A S TM Geotechnical T esting J ournal, V ol. 24, N o. 4, pp. 401-408 15. Marston, A. and Anderson, A. O. (1913), "T heory of Loads on Pipes in Ditches and T ests of Cement and Clay Drain T ile and Sewer Pipe", B ul. 31, I owa E ng rg., Exp erim ent S tation, A m es, Iow a. 16. Naik, T. R., and Sing h, S. S. (1997), " Flow able Slurry Containing F oundry S ands", J ournal of M aterials in Civ il E ng ine ering, Vol. 9, N o. 2, M ay, pp. 93102 17. N antung, T. E. (1993), "D es ig n Criteria f or Controlled L ow S treng th M aterials", Ph. D. T hesis, School of Civil Engineering, Purdue Univ ersity, Aug., pp 344 18. Smith, A.(1991), "Controlled Low Streng th M aterial" Concrete Construction, M ay, pp 389398 (: 2001. 12. 17) 31