Philippe ARNOLD FEDRO, Switzerland

1. Landslide risk mapping
for the entire Swiss national road network
Philippe Arnold
Swiss Federal Roads Office (FEDRO)
3003 Bern
philippe.arnold@astra.admin.ch
Tel. +41 31 323 25 05
Swiss Federal Roads Office FEDRO 1

2. Content
 Introduction
 Some pictures
 FEDRO‘s risk management process
 The tool RoadRisk (step by step)
 Conclusion
Swiss Federal Roads Office FEDRO 2

3. Natural hazards
on Swiss
highways
Swiss Federal Roads Office FEDRO 3

4. Natural hazards
on Swiss
highways
Swiss Federal Roads Office FEDRO 4

5. Natural hazards
on Swiss
highways
Studied Landslides Types
Spontaneous slide
Shallow debris slide
Permanent slide
Swiss Federal Roads Office FEDRO 5

6. Natural hazards on
Swiss highways
Swiss Federal Roads Office FEDRO 6

7. Natural hazards on
Swiss highways
Swiss Federal Roads Office FEDRO 7

8. Risk analysis
Damage types
• Damage types
• (Direct impact, Collision, Deposits on road,
Closure after event, Preventive closure)
Swiss Federal Roads Office FEDRO 8

9. hazard analysis (Phase 1)
• intensy maps (INT)
risk analysis (Phase 2)
• on the road and secondary facilities
• risk of human death
− direct hits
− collision on road
• property risk
− burial: clearance and
restoration costs
− availability: costs as a result of
interruptions
− availability: precautionary
closure
Swiss Federal Roads Office FEDRO 9

10. published at:
www.astra.admin.ch
 Service
 Documents for national roads
 Standard, research, safety
 9 Risk and security management
 89001 Document: Risk concept for natural
hazard on national roads (2009
V.1.30)
Swiss Federal Roads Office FEDRO 10

11. Studied natural Main process type Natural hazard
hazards
Fall Rockfall
Rock avalanche
Icefall
Snow avalanche Flowing avalanche
Powder avalanche
Snow gliding
Flood / Debris flow Flooding
Debris deposition
Bank erosion
Landslide Spontaneous landslide
Permanent landslide
Shallow debris slide
Collapse Dolines
Swiss Federal Roads Office FEDRO 11

12. Occurrence
Probability R Occurence Remarks
probability
0 - 10 years (x) = 1/x – 1/30 Value x based on
past events
> 10 - 30 years = 1/30 -1/100 = 0.023
> 30 - 100 years = 1/100 – 1/300 = 0.0067
Swiss Federal Roads Office FEDRO 12
> 100 - 300 years = 1/300

13. Perimeter Hazard
Assessment
Swiss Federal Roads Office FEDRO 13

14. ≤
Intensy maps (INT)
• Intensity: low, medium, high
• Deposit heights
• How often
• PSpatial Occurence
• Process specific attributes:
e.g,
Avalanche Pressure kN,
Rockfall energy in kJ
Swiss Federal Roads Office FEDRO 14

15. Perimeter Risk
Analysis
Risk calculation
Only intensity
Swiss Federal Roads Office FEDRO 15

16. How calculate the
FEDRO his risks
Step A
check the intensity maps
and their attributes
Swiss Federal Roads Office FEDRO 16

17. Step B
assign the necessary
attributes to the road axes
(DTV, maximum speed
signalled Vmax, closure
costs)
Swiss Federal Roads Office FEDRO 17

18. Step C
The intensity maps are then
overlaid with the road
axes, after which it is only
the sections of road
concerned which are
subjected to further
processing.
Swiss Federal Roads Office FEDRO 18

19. Step D
The sections of road
concerned, together with
all hazard processes and
road attributes are
exported as text files into
RoadRisk.
Swiss Federal Roads Office FEDRO 19

20. Step E
Swiss Federal Roads Office FEDRO 20

21. Swiss Federal Roads Office FEDRO 21

22. Goal
Swiss-wide risk map
Swiss Federal Roads Office FEDRO 22

23. Swiss Federal Roads Office FEDRO 23