Outline 1. Bridge damage to earthquake 2. Seismic analysis and - PDF document

6/22/2015 Outline 1. Bridge damage to earthquake 2. Seismic analysis and evaluation of existing bridges 3. Bridge strengthening methods 4. Cyclic load test of bridge using FRP strengthening technique 5. Strengthening of columns using FRP 6. Application of FRC in ductility improvement of bridge structures 1

6/22/2015 1. Bridge damage due to earthquake Potential Earthquake Sources Tectonic Plate Boundary Bangkok • Megathrust Sunda subduction zone, 500-800 km where Indo-Australian plate moves toward Eurasian plate at a rate of 45-70 mm/year Indo-Australian plate Eurasian plate • Generates frequent and large earthquakes. • Largest recorded quake is M w = 9.1 • Nearest distance from this fault to Sumatra-Andaman Earthquake in 2004, Bangkok is 500-800 km. a cause of destructive tsunami. 2

6/22/2015 Potential Earthquake Sources Earthquake Sources Crustal Faults • There are 13 known active faults in Thailand. 3

6/22/2015 Pan Hospital in 1995 Earthquakes IN Thailand (Mw ≥ 5) : Sourc e Ye a r Ma g nitude Da ma g e L oc a tion 1935 Na a n 6.5 F e lt in BKK 1975 T a a k 5.6 1983 Ka nc ha na buri 5.3,5.9,5.2 (Sri Sa wa t fa ult) 1995/ 96 Chia ng Ra i 5.1/ 5.5 Da ma g e to During 1912 to 2007, ~15,000 earthquakes with M w building s ≥ 3.0, including foreshocks & aftershocks were recorded near Thailand. 1995 Phra e 5.2 Mae Lao Earthquake 5 May 2014 4

6/22/2015 Masonry infill wall failure 5

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6/22/2015 Bridge pier collapse 9

6/22/2015 Bridge pier collapse Unseating 10

6/22/2015 Unseating Unseating 11

6/22/2015 Bridge pier collapse- Flexure failure Bridge pier collapse- Flexure failure 12

6/22/2015 Bridge pier collapse- Bar buckling Bridge pier collapse- Shear failure 13

6/22/2015 Bridge pier collapse- Shear failure Joint failure 14

6/22/2015 Joint failure Beam failure 15

6/22/2015 Abutment failure 2. Seismic analysis and evaluation of existing bridges : Compare structural capacity and demand from earthquake 4 major methods 1. LSP – Linear static procedure 2. LDP – Linear dynamic procedure 3. NLSP – Non ‐ linear static procedure 4. NLDP – Non ‐ linear dynamic procedure 16

6/22/2015 Non ‐ linear static procedure using CPM ตัวอย่างของ Capacity Spectrum Method o Demand vs Capacity 17

6/22/2015  Bridge evaluation procedure using Capacity Spectrum Method (CPM) Analysis for seismic demand from earthquake using o Linear Elastic Time History Analysis and convert it into response spectrum result or “Demand Spectra” Calculate structural capacity using pushover analysis o method to obtain force-lateral displacement of the bridge Compare capacity and demand in the same chart. The o seismic resistance capacity of structures could be directly obtained form the chart 3. Bridge strengthening methods  Reinforced concrete jacketing  Steel plate jacketing  FRP jacketing - Carbon fiber reinforced polymer (CFRP) - Glass fiber reinforced polymer (GFRP) - Aramid fiber reinforce polymer (AFRP) 18

6/22/2015  RC Jacketing 19

6/22/2015 การเปรียบเทียบการวิบัติของเสาที่มีการต่อทาบและไม่ต่อทาบ VDO\video total Zoom Crack column S1 and S1splice (WMV HD 720 ) NEW.wmv การวิบัติเนื่องจากแรงดัด VDO\S1L WMV HD 720 30p.avi การวิบัติเนื่องจากแรงเฉือน VDO\S3S WMV HD 720 30p.avi 20

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6/22/2015  Steel plate jacketing 22

6/22/2015  FRP jacketing What is FRP ? There are three types of fiber 1. Carbon fiber reinforced polymer (CFRP) 2. Glass fiber reinforced polymer (GFRP) 3. Aramid fiber reinforced polymer (AFRP) 23

6/22/2015 “Stress ‐ strain relationship of different fiber type” Type of CFRP SHEET ROD PLATE Advantages: Disadvantages: 1. Light weight 1. Expensive 2. Easy to install 2. Fire vulnerability 3. Environmental Durability 3. Require installation expert 24

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6/22/2015 Stress 35000 ksc Design Stress Limit for CFRP(strain = 0.004) 4000 ksc Strain FRP design for columns Longitudinal direction for enhancing moment resisting capacity Transverse direction for: - increase compressive strength due to confinement effect - increase shear strength by truss action It is more effective to increase the confinement when used in circular column compare to rectangular column The strength and ductility of concrete will increase when wrapped transversely by CFRP 26

6/22/2015 Collapse Behavior of a cylinder wrapped by FRP Concrete cylinder wrapped by 1 layer CFRP. Concrete cylinder with compressive Compressive strength 40 MPa strength of 24 MPa 4. Cyclic load test of bridge using FRP strengthening technique TYPE OF BRIDGE Pile Bent with 4 columns with Pile Bent with 4 columns with 2-layer bracing 1-layer bracing 27

6/22/2015 CLASSIFICATION OF PILE BENT BRIDGE TYPE 3-span bridge 5-span bridge EXPERIMENTAL PROGRAM • Test 4 half-scale model ทดสอบเสา 4 ต้นแบบลดขนาด (half-scale model) • Strengthening Method - GFRP- commercially available in Thailand - Use different type of strengthening location 28

6/22/2015 DETAILING OF BRIDGE SPECIMEN FOUNDATION OF TEST BRIDGE 29

6/22/2015 TEST BRIDGES specimen Strengthening Strengthening Approach Test time Material C1r_GFRP GFRPP Strengthening after test 1 Month C2_GFRP GFRP Strengthening before test 1 Month C3r_GFRP GFRP Strengthening after test 1 Month C4_GFRP GFRP Strengthening before test 1 Month PREVIOUS BRIDGE COLUMN DAMAGE 30

6/22/2015 STRENGTHENING BY GFRP TYPE1 STRENGTHENING BY GFRP TYPE2 31

6/22/2015 CONSTRUCTION STAGE STRAIN GAGE LOCATIONS Setup Strain Gauge Longitudinal = 34 Ea. Strain Gauge Transverse = 12 Ea. Total Strain Gauge = 46 Ea. 32

6/22/2015 LVDT LOCATION Setup LVDT = 20 Ea. CYCLIC LOAD TEST SETUP 33

6/22/2015 DISPLACEMENT HISTORY 3.00 2.00 1.00 Drift (%) 0.00 -1.00 -2.00 -3.00 0 5 10 15 20 25 30 35 40 45 Number of Steps C1r_GFRP 34

6/22/2015 Transverse Actuator displacement prevention installation 35

6/22/2015 • Sensors Load cell Displacement sensor Stain Gage Reference name of strain gages 36

6/22/2015 การติดตั้ง LVDT Measurement of curvature and shear deformation การติดตั้ง LVDT เพื่อวัดการเสียรูปเนื่องจากแรงเฉือน ในคาน Lateral Drift +0.50% Cycle 1 Compressive strength 220 ‐ 270 ksc 37

6/22/2015 Lateral drift +0.75% cycle 1 Lateral drift +1.5% cycle 1 38

6/22/2015 Lateral force – displacement relationship STRENGTHENING PROCEDURE FOR CFRP AND GFRP 39

6/22/2015 1. Grind 4 corner of the columns and beam. 2. Use clean cloth to clean the concrete surface 3. Mix Epoxy Resin using the proper mix ratio according to manufacturing recommendation 3. Use a brush to paint epoxy resin on the target surface 40

6/22/2015 4. Wrap the fiber and use the roller to roll on the fiber surface to make sure that the fiber perfectly attach to the concrete surface. Paint the fiber with epoxy before wrapping another layer. Lateral drift + 0.50 % round 1 41

6/22/2015 Lateral drift + 0.75 % round 1 Lateral drift + 1.50 % round 1 42

6/22/2015 Lateral drift + 3.50 % round 1 Lateral force – displacement relationship 43

6/22/2015 Comparison of Lateral force – displacement relationship C2_GFRP 44

6/22/2015 VDO\Pile bent 2 WMV HD 720 30p.wmv 45

6/22/2015 C3r_GFRP 270 ksc 170 ksc 170 ksc 46

6/22/2015 VDO\Pile bent 3 Before.mpg After Strengthening 47

6/22/2015 VDO\After Repair (Pile Bent3).mpg C4_GFRP 48

6/22/2015 150 ksc 150 ksc 150 ksc VDO\Pile bent 4.mpg 49

6/22/2015 Durability Proof of GFRP ……………. undergoing research Durability test of GFRP - Weight Loss - Tensile Strength Loss Mixtures Mixtures Sodium Hydroxide Cement (NaOH) Extract 50

6/22/2015 “ Weight Loss Test” “Tensile Strength Loss Test” 5 cm Steel plate Fiber + epoxy “Tensile Strength Loss Test” Parameters to be studied - PH of solution - Temperature 51

6/22/2015 5. Strengthening of columns using FRP Col. bxh Shear Aspect Splice Axial Mode of Remarks (mm) Span Ratio Detailing Load Failure (mm) Ratio S1 CFRP 250x350 2050 5.85 No splice 0.2 Flexure GFRP wrap S1 S CFRP 250x350 2050 5.85 25db 0.2 Flexure GFRP wrap S2 CFRP 250x350 1570 4.5 No splice 0.2 Flexure ‐ shear GFRP wrap S2 S CFRP 250x350 1570 4.5 25db 0.2 Flexure ‐ shear GFRP wrap S3 CFRP 250x350 1100 3.15 No splice 0.2 Flexure ‐ Shear GFRP wrap S3 S CFRP 250x350 1100 3.15 25 db 0.2 Flexure ‐ Shear GFRP wrap   Gravity Load P (P) V M F h H=2.05m Contraflexure Point h V M P 52

6/22/2015 6. Application of FRC in ductility improvement of bridge structures 106 53