(Ground Improvement) (Soil Modification) Block Diagram
(Zero Air Voids Curve) (Standard Proctor Compaction Test) ASTM D698 5.5 lb 2.5 kg 12" 30.48 cm 25 25 3 3 1/30 cu.ft 943.9 cm 3 12,375 ft-lb/ft 3 593.96 m-kn/m 3 (Modified Proctor Compaction Test) ASTM D1557 10 lb 4.54 kg 18" 45.72 cm 25 25 5 5 1/30 cu.ft 943.9 cm 3 56,250 ft-lb/ft 3 2699.8 m-kn/m 3
Modified Proctor Zero Air Voids Curve γ d Standard Proctor w % (Line of Optimums) ZAV γ d Zero Air Voids Curve Sr = 100% 50% 70% 80% Line of Optmums w %
γ d A B Zero Air Voids Curve (1) (2) C w % (2) A B C (1) (a) Lambe (b) Sr = 100% σ' = σ u Sr < 100% σ'= σ χu
1 Χ 0 0 Sr 100% Zero Air Voids Curve γ d (1) (2) w % F 1 F 2 u 1 u 2 (1) (2) u 2 < u 1 < 0 F 1 < F 2 (1) (2) (c) (Clod Theory)(Olsen)
(i) (ii) (i) (Impact) (ii) (Kneading - Remolded) (iii) (Static - Piston) (iv) (Vibratory - Vibrator) (i) (Impact) I. (Standard Proctor, ASTM D698, AASHTO T99) ASTM D698 A, B, C, D 4" 6" II. (Modified Proctor, ASTM D1557, AASHTO T180) 4-6 (ii) (Kneading - Remolded)
- - - (Duration) - - (1) ASTM D1561 California Kneading Compactor for Bituminous and Soil (2) Harvard Miniature Test (Casagrande) (iii) (Static - Piston) Piston - ( ) - -
(iv) (Vibratory - Vibrator) ASTM D2049 w% 10% w opt = PL - 5 w% 30% w opt = PL - 2 w opt 2-5 % w opt = PL - 7 1.
c = 0 γ d q u w opt w% w% q u
γ d B C A w opt w% u w% (-) B σ A C ε (Ductile) (Brittle) γ d A B soaking C w opt w% σ1 σ3 A B ε
A, B (Flocculated vs. Dispersed) SEM A, B ( ) 2. ( ) γ d A B w opt w% log σ A e B
( ) 3. k = f (n) γ d w opt w% k w%
- k - k - k -
( ) 1. ( ) - ( ) - 2. - 60-80 psi - 50-70 psi - 40-50 psi 3. ( ) 50-250 Pad Foot Sheep Foot
Pad Foot 4. ( ) - - Pad foot 5 T - 15 T 5 T - 25 T 1000-3000 cycle/min. 5. - ( ) - - ( ) Point of Diminishing γ d 10-15 area of feet N = area of drum 1 100% N
9" (23 cm) 6" (15 cm) (Construction Control) 1. 2. γ d % 95 90 1. (Structural Fill) γ d 95%
2. γ d 90% 1. ASTM D2937 5-10 cm 5 pcf (80 kg/m 3 ) 2. 3. 4. U.S.$ 5000-6000 NT$ 30 (Calibration) 1. 2. 3. 4.
(Construction Quality Assurance, CQA) 1. 2. (Construction Quality Control, CQC) ( ) 3. 1. 2. (Pattern) ( 90%) ( 90%)
(Ground Improvement) (Soil Stabilization, Soil Modification) 1. (Dynamic Compaction) (Heavy Tempting) (Vibroflotation) 2. I. (Drainage) (Sand Drain) (Wick Drain) (Stone Column) II. (Consolidation) (Preloading Surcharge)
3. (Grouting) (Compaction Grouting) 4. ( ) 1. (i) (ii) (Penetration Grouting) =1 psi/ft depth k >= 5 x 10-6 cm/sec (1) / 0.7 mm
(2) / / (3) (Chemical Grout) (4) (Microfine Cement) (1) (3) D15 ( soil) Need = Groutability Ratio, R D 85( grout) R 15-25 or higher Split and Grout, then Split again. ( ) 2. (Compaction Grouting or Displacement Grouting)
20% 12% 1" ( ) 1-3 m ( ) (Vibroflotation) 1930 30% 20% Vibroflot 3-5 m Vibroflot 30 m 2 m Dr 70% 1500 m 2 3-5' N N N N ( ) (Dynamic Compaction)
10-40 200 15-30 m 1 m 15-20 m 1500 m 2 (1) R > 3', Dr 70% (2) 8' (3) 6' Dr 70% (4) (5) 2-3 /ft 2 ( ) (Blasting) 1 m 20 m ( ) (Preload, Preconsolidation) (Surcharge) (Sand Drain) (Wick Drain)
( ) (Electro-Osmosis) 1939 Salzgitter (1) (2) (Rehydrate) (3) (4) 10-20 m ( ) (Stone Column) (1) (2) (3) (4) (5)
1-8 cm 10% Vibroflotation ( ) ( ) / / ( ) ( ) (Soil Cement) 2-12% (1) (2)
, q u (psi) 2% 5% 10% 300 800 1500 < 100 200 500 ( ) (Roller Compacted Concrete, RCC) 5% 2% 1000-5000 psi 12,000 20 ( ) (1) ( ) CaCO 3 (2) CaO (3) Ca(OH) 2 (Pozzolonic Cements) (1) (2) (3) (4) ( ) (1) (2) (3) (4) ( ) 4-10%