Effect of Tsunamis Generated in Manila Trench on the South China Sea and the Gulf of Thailand. Current Research on Tsunamis in Thailand

Transcription

1 Effect of Tsunamis Generated in Manila Trench on the South China Sea and the Gulf of Thailand And Current Research on Tsunamis in Thailand Anat Ruangrassamee Center of Excellence on Earthquake Engineering and Vibration Department of Civil Engineering Chulalongkorn University Bangkok, Thailand

2 Motivation Gas Infrastructure and Petro-Chemical facilities are located in the Gulf of Thailand. 1359km-long offshore pipelines Offshore platforms Obtain current velocity and wave height Funded by Petroleum Thailand Public Company =? Drifted?

3 Background: Earthquakes in South China Sea Tectonics Seismicity Map After Kreemer and Holt, 2000

4 Background: Earthquakes in the Philippines Seismicity Map Data from Bautista et. al., Tectonophysics, 2001

5 Tsunami Simulation Analyzed using TUNAMI modified to simultaneously compute in spherical and cartesian coordinates. Domain of computation in spherical coordinates Domain of computation in cartesian coordinates Rupture

6 Region of Computation Rupture location Domain of computation in Spherical coordinates. Latitude 4 N -26 N Longitude 99 E-123 E R1 Domain of computation in Cartesian coordinates. Latitude 6 N- 14 N Longitude 99 E-106 E R2

7 Bathymetry and Topography

8 Region 1 R2 Bathymetry and Topography R Elevation (m) Elevation (m) Latitude (degree ) Section Longtitude (degree) Section 2-2 Source: ETOPO2 (

9 Region Bathymetry and Topography Elevation (m) Latitude (degree) 2-2 Elevation (m) Section Longtitude (degree) Section 2-2 Source: Hydrographic Department, Royal Thai Navy

10 Estimation of Return period Lat 15 Epicenter 5<Mw<10 source : ANSS CMT Annual rate of exceedance of Mw Distribution of Earthquake Source : ANSS Start date: 1963 End date: Distribution of Earthquake Least-Square Mw log N = M Mw Return Period (year) Return period Lon Source:ANSS Mw

11 Earthquakes in the Philippines Seismicity Map Data from Bautista et. al., Tectonophysics, 2001

12 Fault Model Depth Strike Dip Displacement Slip Width Length Source: IOC (1997)

13 Papazachos et al. s model (2004) For subduction earthquakes Length Estimation of Fault Parameters Area Width Displacement

14 Estimation of Fault Parameters Papazachos et al. s model Mw L Area W U (ricther) (km) (km 2 ) (km) (m)

15 Analytical Cases Case 1 Case 2 Case 3 Case 4 Case 5 Case 6

16 Case 1, Mw=9.0 Depth (H) = 25 km Strike (θ) = 0 Dip (δ) = 30 Slip (λ) = 90 Disp. (u) = 9.5 m Analytical Cases Deformation of ocean bottom using Mansinha and Smylie s equations (1972) Fault

17 Case 2, Mw=8.5 Depth (H) = 25 km Strike (θ) = 0 Dip (δ) = 30 Slip (λ) = 90 Disp. (u) = 9.5 m Analytical Cases Deformation of ocean bottom using Mansinha and Smylie s equations (1972) Fault

18 Simulation Results

19 Time of Arrival Mw = 9.0

20 Tsunami Height Maximum Case Height (m) M w

21 Tsunami Height Mw = 9.0 Mw = 8.5 In Vietnam, tsunami height = m depth

22 Current Velocity Mw = 9.0 In Vietnam, current velocity = m depth

23 Estimation of Current Velocity for Long Wave v =η g / h η h v = wave height = water depth = current velocity

24 Comparison of Current Velocity Current (m/s) 0.03 Estimated Analyzed Current (m/s) Time (hrs) Estimated Analyzed Time (hrs)

25 Comparison of Current Velocity Analyzed result Estimated result

26 Conclusions 1. The earthquake causes large wave height and current velocity off-shore South-eastern China, and Northwestern Philippines, and Eastern Vietnam. The Gulf of Thailand is less affected by the tsunamis generated by fault ruptures off the shore of the Philippines because of the diffraction of tsunamis at the southern part of Vietnam. 2. Towards Malaysia and Thailand, the tsunami slows down due to the relatively shallow water depth. The tsunami arrives Malaysia in about 9 hr, and Gulf of Thailand in 12 hr. 3. The maximum wave height is about 0.65 m near the shores of Thailand. And the maximum wave current is about 0.1 m/s.

27 Ongoing Research Projects to Mitigate Tsunami Effects Effect of tsunamis on the Gulf of Thailand Funded by Petroleum Thailand Public Company Tsunami database for early warning Funded by National Disaster Warning Center Tsunami risk analysis of buildings in Thailand Funded by Department of Meteorology, Ministry of Information and Communication Technology And Ministry of Environment Collaboration with AIT and local universities Tsunami load on evacuation buildings Funded by Department of Civil Works and City Planning, Ministry of Interiors Collaboration with Thammasart U, AIT, KMUTT Chulalongkorn University obtained about 3+ M USD for tsunami research in 2 years

28 Ongoing Projects to Mitigate Tsunami Effects Effect of tsunamis on the Gulf of Thailand Tsunami database for early warning Tsunami risk analysis of buildings in Thailand Tsunami load on evacuation buildings

29 Tsunami Database hardcopy Earthquake magnitude Depth Location Database Arrival time Processing Tsunami height

30 Seismicity in Source: Petersen et al. (2004) Seismicity around Thailand

31 Hypothetic Earthquakes in the West Seismicity Epicenters Petersen et al. (2004) Source: GEBCO

32 Seismicity Hypothetic Earthquakes in the East Epicenters Petersen et al. (2004) Source: GEBCO

33 Fault Parameters Depth Dip Strike Displacement Slip Width Length Epicenters Source: GEBCO Cases Mw 7 9 Various epicenters About 1000 cases

34 Ongoing Projects to Mitigate Tsunami Effects Effect of tsunamis on the Gulf of Thailand Tsunami database for early warning Tsunami risk analysis of buildings in Thailand Tsunami load on evacuation buildings

35 Source: HAZUS, FEMA Hazard (ground shaking) Sonoma Marin Napa Solano San Joaquin Contra Costa San Francisco Earthquake Risk Analysis Residential damage Sonoma Napa Solano Marin San Joaquin Contra Costa San Francisco Economic loss Sonoma Napa Solano Marin Contra Costa San Francisco Alameda Alameda Alameda SA [1.0 sec] 1.2g miles San Mateo Santa Cruz Santa Clara Monterey M San Benito miles San Mateo Residential Damage [# per square mile] Over to to to 50 5 to 10 1 to 5 0 to 1 Santa Cruz Santa Clara Monterey San Benito 0 10 San Mateo Loss Density [$M per sq.mi.] Over to to 50 5 to 10 1 to to 1 Less than 0.2 miles 20 Santa Cruz Monterey Santa Clara San Benito Powerful tool for disaster management and decision making

36 Background on Tsunami Risk Analysis Hazard map (tsunami height) Buildings damage (m) Obtained from - Past experience - Numerical analysis prob. of damage/loss Probability of Exceeding a Damage State Fragility Curve Damage in Secondary Members Damage in Primary Members Collapse Inundation height (m) hazard Severe Damage Few Damage Powerful tool for disaster management and decision making Developed from - Past experience damage database - Experiment push-over test - Numerical analysis push-over analysis

37 Structural Damage Wall punching Erosion Bending failure Lateral bending of beams

38 Methodology Observation Inundation height Damage level based on overall damage Building location building Number of stories - No damage Function of building - Damage in secondary members - Damage in primary members - Collapse Probability of certain damage levels One-story buildings Buildings taller than one story Inundation height

39 Database of Structural Damage (

40 Observed Data 120 observed reinforced-concrete buildings in database Ranong, 9 bldgs. Phang-Nga, 30 bldgs. Phuket, 77 bldgs. Satun Krabi, 3 bldgs. Trung, 1 bldgs. Distribution of observed reinforced-concrete buildings in the South of Thailand

41 Definition of Damage Levels Damage Level 0: No damage Damage Level 1: Damage in secondary members Damage in non-structural components Damage Level 2: Damage in primary members Damage in structural components Damage Level 3: Collapse A building cannot sustain gravity load

42 Example of Buildings with Damage Level 0 No damage

43 Example of Buildings with Damage Level 1 Damage in secondary members Cracks on a wall Wall punching

44 Example of Buildings with Damage Level 2 Damage in primary members Small cracks in a column Bending failure of column

45 Example of Buildings with Damage Level 3 Collapse Severe joint failure Absolute destruction

46 Methodology Inundation height Building location Number of stories Function of building Observation Damage level based on overall damage building - No damage Maximum Likelihood Function - Damage in secondary members - Damage in primary members - Collapse Probability of certain damage levels One-story buildings Buildings taller than one story Inundation height

47 Fragility Curve of all Buildings Damaged by a Tsunami Propability of Exceeding Damage level Damage level 1 Data averaged over a 0.5 m interval Actual data Inundation Height (m) Propability of Exceeding Damage Level Damage level Inundation Height (m) Propability of Exceeding Damage Level Damage level Inundation Height (m) Propability of Exceeding Damage Level All damage levels Damage level 1 Damage level 2 Damage level Inundation Height (m)

48 Development of Building Database in Southern Thailand Provinces No. of Buildings Krabi 17,879 Trang 8,470 Ranong 7,387 Phang-Nga 11,493 Phuket - West coast - East coast 64,003 37,039 26,964 Satun 8,424 TOTAL 117,656

49 Pilot Survey Patong Beach, Phuket

50 Pilot Survey Paper form Handheld GIS and GPS GPS location Buildings

51 Detailed Survey Form Age No. of occupants (day & night) % of opening No. of stories Occupancy Type Structure Type

52 Quick Survey Form

53 Ongoing Projects to Mitigate Tsunami Effects Effect of tsunamis on the Gulf of Thailand Tsunami database for early warning Tsunami risk analysis of buildings in Thailand Tsunami load on evacuation buildings

54 Development of Design Guideline for Evacuation Buildings IKONOS Image 2.5 km Khaolak In some areas, inundation extends more than 2 km from the shoreline. A vertical evacuation would be necessary. Opening is very effective. 12 km 1 km =? =? Tsunami force on buildings with openings

55 Damage of Building w/wo Opening Building with opening Dowel Beam Column ผน งท ไม ม ช องเป ดพ งเส ยหาย ผน งท ม ช องเป ดไม พ งเส ยหาย

56 Scale 1:100 Experimental Setup

57 Experimental Setup Length 40 m, Width 1 m, height 1 m

58 Instrumentation Wave guage (Wave height) Propeller (Velocity) Pressure sensor (Pressure) Load cell (Base shear force and bending moment)

59 Experimental Parameters Beach slope (Khaolak and Phuket) Building shapes (square, rectangle, and octahedron) Percentage of opening for (0%, 25% 50%) Wave height (3 cm. 8 cm.)

60 Building shapes Building Models 15 cm x 15 cm x 15 cm 24 cm x 15 cm x 15 cm Dia. 15 cm x15 cm Opening

61 Wave at Building h = 30 mm h = 60 mm h = 80 mm

62 Pressure on Building P3 P2 P1 opening 25%, 50%, wave height 60 mm pressure (cm) P1 P2 P time (sec)

63 Effect of Opening on Base Shear Force Square Khaolak opening Wave Height 30 mm 60 mm 80 mm 00% 0.84 (100%) 1.73 (100%) 2.37 (100%) 25% 0.70 (83%) 1.50 (87%) 2.13 (90%) 50% 0.43 (51%) 0.90 (52%) 1.37 (58%) Phuket Opening 40 mm Wave Height 60 mm 80 mm 00% 0.70 (100%) 1.85 (100%) 3.77 (100%) 25% 0.52 (75%) 1.58 (85%) 3.22 (85%) 50% 0.44 (63%) 1.15 (62%) 2.67 (66%)

64 Comparison of Velocity FEMA-55; Tsunami( V = 2 gd s ) Velocity ความเร วน า (เมตร/ว นาท ) (m/s) ป าตอง2 (Matsutomi) ป าตอง (ท ปร กษา) เขาหล ก (Matsutomi) Ramsden&Raichlen (1990) ( V = 1.8 gd s ) CCH & FEMA-55 Lower Bound ( V = ds t) gh FEMA-55; Upper Bound ( V = gd s ) กมลา (Matsutomi) กมลา (ท ปร กษา) 1 For Impact Load in FEMA-55 ( V gd s ) ป าตอง1(Matsutomi) Inundation Height (m) ความล กน าน งหร อความส งของคล นท ปะทะโครงสร าง (เมตร) ร ปท 2.27 ความส มพ นธ ระหว างความเร วน าก บความล กน าน งหร อความส งของคล นท ปะทะโครงสร าง

65 Estimation of Velocity from Available VDOs Source: Wave of destruction website Location: Khaolak

66 Distance (m) Estimation of Velocity from Available VDOs y = m2 * M0 Value Error m Chisq NA R NA 5 Velocity = 8 m/s Time (s)

67 1 Source: Wave of destruction website Location: Patong Beach 2

68 2 1 Distance: m Time: 0.04 (s/frame) x 51 (frame) = 2.04 second Velocity: / 2.04 = 8.90 m/s

69 Evacuation Building Designed using Tsunami Loads Fender elements are used to absorb the energy transferred from ship impact Designed by Amorn Pimanmas, SIIT, Thammasart University

70 Case Study Building of Meteorological Department NEED CALIBRATION WITH AN ACTUAL CASE wave height = 4.4 m above ground Velocity of wave (From Matsutomi and VDO) = 6-8 m/s Distance from shoreline = 220 m Elevation of first floor = 0.90 m

71 Case Study Building of Meteorological Department Full-scale push-over test will be conducted on Dec 2007 Building Actuators (about 75 tons) Tsunami Reaction frame Objectives: - Determine the capacity of the building - Estimate the tsunami force on the building at the time of 26 Dec 2004 tsunami - Get the estimate of tsunami velocity - Verify material modeling of RC buildings for lateral load analysis (seismic design)

72 Center of Excellence in Earthquake Engineering and Vibration Department of Civil Engineering Faculty of Engineering Chulalongkorn University Bangkok, Thailand Tel: Fax: