Rahvusvaheline puitarhitektuuri konverents

Transcription

1 Experiences from Modern Timber Bridge Building Rahvusvaheline puitarhitektuuri konverents Tallinn Hauke Burkart NPRA Bridge Section

2 Topics Short history of modern Norwegian timber bridges Timber bridge design Examples on details Where timber bridges pay off

3 About myself Hauke Burkart Master in Structural Engineering Worked in the NPRA since 2009 Work on Timber Bridges: Instrumentation of moisture and bar forces Planning, design and quality Assurance Inspection, service and maintenance

4 Modern Norwegian Timber Bridges Currently 190 timber bridges in traffic 100 pedestrian bridges 80 road bridges Bridge length vs year built

5 Modern Norwegian Timber Bridges Evenstad Bridge m long, 5 equal spans of 36 m Traffic loads Slotted plates

6 Modern Norwegian Timber Bridges Evenstad Bridge m long, 5 equal spans of 36 m Traffic loads Slotted plates Design was probably better before

7 (Modern) Norwegian Timber Bridges Tolga Bridge 1859

8 Modern Norwegian Timber Bridges What has influenced the design? Cost effective measurements Concrete engineers and concrete bridges Newer building methods without previous experience The thought that creosote makes everything work

9 Modern Norwegian Timber Bridges (Concrete) Timber Bridges

10 Modern Norwegian Timber Bridges (Concrete) Timber Bridges

11 Timber Bridge design The Pyramid!

12 The Inverted Pyramid!

13 The Inverted Pyramid!

14 The Inverted Pyramid House Photo: Matthew Bronski / Durable Design: Lessons from Historic Wood Structures

15 Carpenters building bridges? Photo: unknown/google search

16 Abutment design Current abutment design quite different from traditional concrete abutments

17 Abutment design

18 Abutment design

19 Abutment design

20 Abutment design

21 Abutment design, do we know it will work?

22 Abutment design Opening probably large enough to self-clean Edge sill should be somewhat longer, but is beyond end of deck Stainless steel flashing beyond end of deck Concrete nose Crossbeam shorter than bridge deck Stainless steel flashing between concrete and timber

23 Abutment design Simplified solutions, works with roof structures

24 Abutment design As long as the concrete is dry -> no problem White wood + wet concrete -> not good Use granite instead? Non-Horizontal surface

25 Abutment design

26 Abutment design

27 Vegetation Good stone pitching important

28 Cross-beams close to abutment Difficult Possible Simple

29 Cross-Beams

30 Cross-Beams

31 Bracing

32 Bracing / screwed plates

33 Hand rail Flashing damaged by snow ploughing equipment

34 Timber and Parapets

35 Timber and Parapets

36 Timber and Parapets

37 Don t be fanatic about timber

38 Possible to discuss robustness of timber structures instead of durability of timber as a material? Edge sill Membrane Asphalt Bridge deck Screws Parapet

39 Saftey Barriers? 1. Barrier 2. Barrier 3. Barrier

40 Stabekk Pedestrian Bridge 2016

41 Where Timber Bridges pay off Bridges built on existing foundations

42 Where Timber Bridges pay off Bridges built on existing foundations

43 Where Timber Bridges pay off Bridges moved or to be taken down and stored

44 Where Timber Bridges pay off Traffic safety enhancement

45 Where Timber Bridges pay off Short erection time Especially railway crossings

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47 Thank you for your attention!