YWXY º º t rzyywxyhw^y º v ƒ n x¹ s Comarison of Preiction Moels for Permanent Deformation in Trackbe Founation Materials ã, ¹ ã, ƒ ã, ãã Yujin Lim *, Hojin Cho *, DaeSeong Kim *, Jinwoog Lee ** Abstract Permanent eformation in trackbe founation is generate ue to reeate track loaing. Permanent eformation in the trackbe founation can cause irregularities of the rail. It is critical to reict magnitue of ermanent eformation in esign of the trackbe founation thickness in orer to rovie stability to the rail structures. A comarative stuy of ermanent eformation reiction moels for unboun granular materials was erforme in orer to check reliability an ros an cons. A large triaxial reetitive aaratus was aate to erform cyclic triaxial tests to characterize ermanent eformation in the track founation materials such as unboun granular soils. It is verifie that confining stress, shear strength arameters (shear stress ratio) an number of loa reetition are critical esign arameters in construction of reiction moel for ermanent eformation.. rœ ž ša x¹ l ¹vy Ž ˆ x¹ s ï z º v vy Ÿ x¹ vƒ l x¹ vƒ r Ž ƒ ºy ƒ z ƒ ƒ x¹ º½ y ƒ x¹s rž l ¹vy Ž ˆ º v ƒ n vy ˆ ˆˆ x¹ vƒ ƒ ±Ž Ž ƒ l vvy º ƒ º v n x¹s q q x º Permanent eformation, Preiction Moel, Shear Stress Ratio, Large Triaxial Cyclic Test, ää ï z vy Ÿ ƒx¹ vƒ l ƒx¹ Ÿ ª vy º v z vƒ l ª ƒ n ƒ y m v mžl z vy Žºy«ƒ w º n º r vy º ƒ ½ ƒx¹ ƒ Ò åø á ÒÑÑá Ð Ñ ãñ Ñ(yujin@cu.ac.kr) ãø á ÒÑÑá Ð Ñ ãñ Ñ ãã Ó ãõ Ó
l ƒx¹ z x¹ m r m s U y ƒ ƒ n x¹ s š S yž r D30cm, H60cm ˆ³ ˆ ¹vy Ž ˆ ƒ ƒ ƒ º v ƒ n vy ˆ ˆˆ x¹ s. ää Óú ô þò äää Óú ô ƒ nm ƒ º v ƒ ƒ x¹o vƒª º½ s v m z vƒ x¹ l vyº m w my ˆ() ¹ f ( s n : ) F ( ) () ƒ x¹o f (s) Ÿ lv l ª m ¹ l F (n) vyº m ¹ Table ƒ ƒ vvº n x¹ s Table Permanent Deformation Preiction Moels Moel Equation Parameter Power Moel Moifie Power Moel A b e ξ e2 e3 x¹o º A, b v q x e, e, e 2 3 n ξ ± l / σ @ 00, 000 σ f Power rate Moel log log C λ log º e ƒx¹o wš ˆ ƒx¹o C, n Semi log Moel log : n
a Rare-rocess theory A ( σ, ω ) ormalize Moel r k 0.95S a ri a ki + + S b ri b ki / r σ ln ln k σ Ÿ l ω a n A Ÿ l a b, a, ri ri ki S σ, b º 0.95S ki Ÿ l x¹o ( ) ªwš ˆvƒ ƒx¹o VESYS Moel DTU Moel TTI Moel δ a α ( ) µ α σ z β γ A ( ) ( ) z ( ) ξ o ( r ) e ρ ξ β ( ) 2 v h µ ƒx¹o ºy«ƒx¹o m wš ˆvƒ ºy«ƒx¹o vy º α º e x¹ k ºy«ƒx¹o z º σ l z Ž ª A, α,, β γ n δ z x¹k a º,, o r β ρ n ºyx¹o z vƒ ³ x¹o v h z ξ,ξ nv y 2 Table v z g m ³ ƒ x¹ s l v (Li an Selig []). ½, º v g y ƒ x¹ vy º, Ž v Ÿ l ª l,, v z³ n ª m v¹ v (Barksale [2]; Selig an Chang [3]). Table ƒ Ž v zz s vy º ºyx¹o, º ˆ ƒx¹o, Ž g Ÿ l l, w s ¹ˆ. ½ VESYSs x¹o vƒ l š. zz s s q x
z s q x v ª ºˆ q x š ±Ž, q q x m s y x ƒ zzr ˆ r ƒ q. ˆ r ƒ x¹ s ƒ rƒ q x ƒ v ƒ q zr Ž. ääøú Óú äää áïã Ñî Óú Ð n ƒ º v n Mohr-Coulomb ± e m r± l ek x¹vƒ ƒg ª ½ l τ f τ/τ f m ¹ um l n x¹ vƒ y ekƒ l ƒ Ø r l τ/τ f l l r z ƒ n x¹ l ª n x¹ vƒˆ«ekƒ x¹ˆ vy Ž ˆ Žƒ ˆ º v n ˆ CD ˆˆ Ÿ ƒ Ž ˆ ƒ º v n ƒ ƒ º ˆ n tƒ Table 2~Table 4 ˆ m Žk Table 5 r m l Tabel 6vTable 7 Ž ƒ l v e Ÿ l l Fig. ¹vy ˆ 0000 ºŽ vy ˆˆ U Table 2 Sieve analysis results z Quarry A Quarry B D 0 0.2 D 30.35 ˆ D 60 0 o (C C ) 0.9 (C U ) 50 #200 4 #4 47.5 ¼ zo USCS W
ˆ Table 3 Comaction test results z Quarry A Quarry B k(%) 4.3 5.9 k(t/m 3 ) 2.402 2.33 Table 4 Secific gravity an absortion ratio of the materials use for RC tests z Quarry A Quarry B ( S ) 2.769 2.757 ¼ (%) 0.87 0.34 ƒ (PI,/%) P P Table 5Test Results of Static Triaxial Test Quarry CãkPaã ãde.ã A 67 45.35 B 46 47.68 Fig. Large Triaxial Cyclic Test Aaratus
Table 6Test conitions for Large Reetea Loa Test (Quarry A) Confining stress (σ 3, kpa) 35 69 Shear stress ratio τ/τ f Axial stress (σ, kpa) Loa the number of reeate loaing () 0.3/0.7 86.25/249.96 5,000 ºŽ 0,000 º 0.5/0.7 59.26/249.96 5,000 ºŽ 0,000 º 0.7/0.7 249.96 0,000 º 0.3/0.7 24.39/360.49 5,000 ºŽ 0,000 º 0.5/0.7 229.69/360.49 5,000 ºŽ 0,000 º 0.7/0.7 360.49 0,000 º Confining stress (σ 3, kpa) 35 Table 7 Test conitions for Large Reetea Loa Test (Quarry B) Shear stress ratio τ/τ f Axial stress (σ, kpa) Loa the number of reeate loaing () 0.3/0.7 99.9/287.79 5,000 ºŽ 0,000 º 0.5/0.7 83.99/287.79 5,000 ºŽ 0,000 º 0.7/0.7 287.79 0,000 º 0.3/0.7 33.48/384.49 5,000 ºŽ 0,000 º 69 0.5/0.7 245.8/384.49 5,000 ºŽ 0,000 º 0.7/0.7 384.49 0,000 º äää Óú ÑÑ x¹o ˆ vƒ x¹o ƒ ºyx¹o x¹k δ mz x¹o ƒ¹x LVDT m x¹k ˆ³ xº l x¹o t º ƒ x¹o x¹o ƒ nx l xv l ek r Fig. 2 ~ Fig. 3 vy º m l ª mv Ž m x¹o ª vƒ º rvy º e x¹o vƒ ²y hyerbolic ¹ ƒ¹ ƒ y ½ l ª m x¹o vy m vƒ r vy º ƒr x¹o vƒ x¹o ƒy l 0.7-0.7 B ƒ ƒ n x¹o A ƒ ƒ n x¹oy vƒ B ƒ n ˆ ˆA ƒ n ˆ y
Ÿ l ª l e B ƒ ƒ n A ƒ ƒ n ºy«ƒ et m± y x¹vƒ zƒ n x¹ vƒ ª um l n ˆ ƒ j º Fig. 2 Permanent strain with number of loa reetition obtaine using crushe rocks of quarry A (confining stresses: 35kPa, 69kPa) Fig. 3Permanent strain with number of loa reetition obtaine using crushe rocks of quarry B (confining stresses: 35kPa, 69kPa) ääñï y ƒ n º v ƒ n x¹ s m x¹ s zƒ r D30cm H60cm ¹ˆ³ vy Ž ˆ ˆˆ º v ƒ n x¹ ƒ v ºy«ƒ ƒ ±Ž vyž ˆ mz Ž ƒ l v vy º ƒ º v n x¹s q q x º g Žk ƒ º v n x¹ vƒ ƒ ±Ž
vy º ª m l ª m v Ž m x¹o ª vƒ vy º e x¹o vƒ ²y hyerbolic ¹ ƒ¹ ƒ y ½ l ª m x¹o vy mvƒ r vy º ƒr x¹o vƒ x¹o ƒy Ï Ô y ƒv ƒ v º Ž ± v v v ƒz ƒ t zmƒ Ñö [] D. Li, E. T. Selig (998) Metho for railroa track founation esign. I: eveloment, J. eotech. eoenv. Eng., ASCE, 24(4),. 36-322 [2] R.D. Barksale (972) Laboratory evaluation of rutting in base course materials, Proc. 3r Int. Conf. on the Structural Design of Ashalt Pavements, Lonon [3] E. T. Selig, C. S. Chang (98) Soil Failure Moes in Unraine Cyclic Loaing, Journal of eotechnical Eng. Division, ASCE, 07(T5),.539-55