monitoring bridges by gnss - fig · monitoring bridges by gnss • 7 bridges, case studies •...

FIG Congress 2010 Facing the Challenges – Building the Capacity Sydney, Australia, 11‐16 April 2010  1

Dr Gethin Wyn Roberts, Chris Brown, Dr Oluropo Ogundipe

Monitoring Bridges by GNSS

• 7 Bridges, case studies

• Large and small suspension bridges, one viaduct, one cable stayed bridge

• New tests on the Severn Suspension Bridge, antennas on cables and towers

FIG Congress 2010 Facing the Challenges – Building the Capacity Sydney, Australia, 11‐16 April 2010  2

Nottingham Wilford Suspension Bridge

London Millennium Suspension Bridge

FIG Congress 2010 Facing the Challenges – Building the Capacity Sydney, Australia, 11‐16 April 2010  3

Humber Bridge

FIG Congress 2010 Facing the Challenges – Building the Capacity Sydney, Australia, 11‐16 April 2010  4

Forth Road Bridge

Avonmouth Viaduct

FIG Congress 2010 Facing the Challenges – Building the Capacity Sydney, Australia, 11‐16 April 2010  5

Height Results

Seohae Grand Bridge, Korea Location: From Kyeonggi-do Pyeongtaek-si Poseoung-myun Naegi-ri To Choongcheongnam-do Dangjin-gun Songak-myun Bokwoo

FIG Congress 2010 Facing the Challenges – Building the Capacity Sydney, Australia, 11‐16 April 2010  6

Severn Suspension Bridge

9 GNSS receivers

2 reference stations

Reference station and backup

Post Processed OTF

FIG Congress 2010 Facing the Challenges – Building the Capacity Sydney, Australia, 11‐16 April 2010  7

Antenna locations, tower and cable

Movements location A, 40 min period

FIG Congress 2010 Facing the Challenges – Building the Capacity Sydney, Australia, 11‐16 April 2010  8

Location B 10 mins

Location B 1 min

FIG Congress 2010 Facing the Challenges – Building the Capacity Sydney, Australia, 11‐16 April 2010  9

Tower Longitudinal movements, 10 mins

Location A spectral analysis

FIG Congress 2010 Facing the Challenges – Building the Capacity Sydney, Australia, 11‐16 April 2010  10

Location B spectral analysis

Tower T1 spectral analysis

FIG Congress 2010 Facing the Challenges – Building the Capacity Sydney, Australia, 11‐16 April 2010  11

Height 4 locations 10 mins

Conclusions

• Valuable monitoring tool and technique

• Forth and Severn suffer wire breaks

• Long term monitoring?

FIG Congress 2010 Facing the Challenges – Building the Capacity Sydney, Australia, 11‐16 April 2010  12