IMIA WGP 59 (08) Bridges Construction, Insurance and Risk Management

Transcription

1 IMIA WGP 59 (08) Bridges Construction, Insurance and Risk Management IMIA Conference Gleneagles September 17, 2008

2 The Team Heiko Wannick Munich Re Munich, Germany (Chairman) Alexander Artamonov Gefest Moscow, Russia Christian Bendel Munich Re Munich, Germany Chris Blueckert Zurich Insurance Stockholm, Sweden Hervé Landrin Munich Re Munich, Germany Mike Spencer Zurich Insurance London, UK Philip Wallace Infrassure Zurich, Switzerland Louis Wassmer Zurich, Switzerland 2

3 Ancient Times 3

4 A Bridge too... 4

5 Modern Times 5

6 Landmarks 6

7 Recent Highlights 7

8 Current Challenges 8

9 The Future 9

10 Agenda Technical Aspects Risk Exposure and Underwriting Considerations Loss Examples PML-Considerations Risk Management 10

11 Technical Aspects 11

12 Girder Bridges 12

13 Launching Girder Method 13

14 Launching Girder Method 14

15 Incremental Launching 15

16 Incremental Launching 16

17 Cable Stayed Bridges 17

18 Cable Stayed Bridges 18

19 Suspension Bridges 19

20 Suspension Bridges 20

21 Arch Bridges 21

22 Arch Bridges 22

23 Selection Criteria Topography Geology Costs Constructability Aesthetical aspects Environmental aspects Construction risks 23

24 Risk Exposure and Underwriting Considerations 24

25 Risk Exposure Natural Hazards Fire Faulty Design, Materials, Workmanship Third Party Liability Contractors Plant and Equipment 25

26 Natural Hazards Earthquake Flooding Windstorm Landslide Lightning 26

27 Earthquake 27

28 Flooding 28

29 Flooding 29

30 Windstorm 30

31 Monitoring System at Stonecutters Bridge 31

32 Fire Hazard Use of wooden formwork and falsework Welding and cutting works Placement of bituminous pavement 32

33 Fire Hazard 33

34 Fire Hazard 34

35 Faulty Design, Materials, Workmanship Design considerations Purpose of the bridge Temporary + permanent loads Durability and lifespan Architectural, aesthetic and environmental aspects Constraints Overall budget available Construction time schedule Geographic site conditions Ground conditions Sea/river/lake conditions AASHTO Standard Specification for Highway Bridges BS 5400 Specification for leads on Steel Concrete and Composite Bridges ASCE Recommended design loads for Bridges OHBDC the Ontario Highway Bridge Code Japan Road Association design Manual for design of highway bridges 35

36 Underwriting Considerations Experience and reputation of designers and contractors Temporary works design method statements Natural hazard exposure Outside influences (e.g. external impact by vessels) Construction programme Third Party exposure Plant and equipment Project risk management approach 36

37 Risk Assessment Matrix Technical Segment Hazards / Sensitivity Factors* Type of Bridge Natural Exposure External Collapse Fire, Explosion Construction, Design Girder Frame Arch Suspension Cable Stayed Components Foundations, Abutments Falseworks Formwork (Steel) 3 (Wood) 1 (Steel) 3 (Wood) Bridge Deck Cantilever Pylons Main Cable Caissons *Sensitivity Factors: 0 = unaffected, unlikely to suffer damage 1 = Low, minor damage, can be repaired 2 = medium, significant damages, may require alternative working method for repair 3 = high, catastrophic failure of bridge, collapse

38 Relevant Warranties Deviation from time schedule Structures in E/Q zones Flood protection measures Damage to U/G-services Fire fighting facilities Piling and retaining walls 38

39 Loss Examples 39

40 River Main Crossing, Germany 40

41 Savannakhet Mekong River Crossing, Laos 41

42 Can Tho Bridge, Vietnam 42

43 Hyderabad Flyover, Pakistan 43

44 Jintuo Bridge, P.R. of China 44

45 PML-Considerations 45

46 PML-Scenarios for Bridge Construction Flooding Earthquake Aircraft impact Ship collision Sabotage Traffic accidents on bridge deck 46

47 Case Study 1: PML for a Girder Bridge Scenario: Impact by a large freight ship to one of the piled supports of the bridge deck Piles: 20% Bridge deck (surface): 20% Bridge girders: 20% Removal of debris: 100% of SI (PML in % damage of permanent works for individual construction elements) 47

48 Case Study 2: PML for a Suspension Bridge Scenario: Impact by windstorm at the most critical stage before the bridge deck and the suspension cables have been jointed together Steel and concrete works: 67% Hanging systems: 10% Extra cost: 100% Removal of debris: 100% of SI (PML in % damage of permanent works for individual construction elements) 48

49 Case Study 3: PML for a Cable Stayed Bridge Scenario: Massive Ship collission against pier and girder, pier unprotected by artifical island Steel and concrete works: < 20% Suspension systems: 10% Extra cost: 100% Removal of debris: 100% of SI (PML in % damage of permanent works for individual construction elements) 49

50 No construction project is risk free. Risk can be managed, minimised, shared, transferred or accepted. It cannot be ignored. Sir Michael Latham,

51 Code of Practice for Risk Management BRIDGE The International Association of Engineering Insurers 51

52 Risk Management Process REPORTING MONITORING & REVIEW DEFINITION OF OBJECTIVES Objektives? Success Criteria? Risk Categories? HAZARD IDENTIFICATION What can happen? How can it happen? RATING CRITERIA RISK ANALYSIS RISK EVALUATION Determine Likelihood Consequence RISK MITIGATION Screening Options Evaluation Actions Re-Evaluation MITIGATION COST RESIDUAL COST Quantify Mitigation Cost Quantify Residual Risk RISK RANKING 52

53 Conclusion Some bridge types are sophisticated structures requiring application of advanced and risky construction techniques Bridges under construction are particularly exposed to natural hazards, faulty design and external impact A number of recent losses have shown the vulnerability of bridge construction, especially in regard to temporary works Professional risk management standards have yet to be implemented into bridge construction projects A Code of Practice similar to the ITIG-TCoP is recommended 53

54 Thank you for your attention! Heiko Wannick Munich Reinsurance Company Topic Network Construction 54