IABSE SYMPOSIUM ENGINEERING THE FUTURE SEPTEMBER 21-23, 2017
PROOF LOAD TESTING
OF VIADUCT DE BEEK
Eva Lantsoght, Rutger Koekkoek, Yuguang Yang,
Cor van der Veen, Dick Hordijk, Ane de Boer

OVERVIEW
• Introduction: load testing
• Viaduct De Beek: description
• Preparation of proof load test
• Execution of proof load test
• Assessment of viaduct De
Beek Testing of Ruytenschildt Bridge

IABSE SYMPOSIUM ENGINEERING THE FUTURE SEPTEMBER 21-23, 2017
WHY LOAD TESTING? (1)
Bridges from 60s and 70s
The Hague in 1959
Increased live loads
common heavy and long truck (600 kN)
End of service life + larger loads

PROOF LOAD TESTING OF
BRIDGES
• Apply predetermined load
to bridge
• Information lacking
• Damage due to ASR, …
• Proof load testing
• Immediate approval of
bridge
• Recalculate updated β

VIADUCT DE BEEK (1)
• RC slab bridge of 4 spans
• Built in 1963
• Parabolic change in height
• Proof load test at shear- and
flexure-critical position in first
span

VIADUCT DE BEEK (2)
• Core drilling: fck = 44.5 MPa &
fcd = 30 MPa
• QR 24 steel (plain bars), fyk =
252 MPa
• Insufficient flexural capacity
• Reduction of 2 lanes to 1 lane
• Lowest capacity: span 2
• But: span 2 over highway =>
testing not allowed for safety

PREPARATION OF LOAD
TEST – TARGET PROOF LOAD
Reliability level β Pb
[kN]
Ps
[kN]
EC ULS 4.3 1656 1525
RBK Design 4.3 1649 1516
RBK Reconstruction 3.6 1427 1311
RBK Usage 3.3 1373 1262
RBK Disapproval 3.1 1369 1257
EC SLS 1.5 1070 976
• Find target proof load that results in same sectional moment or
shear as load combination of code
• With LFEA
• Load combination with load factors depending on safety level
• Exception γDL = 1.10

PREPARATION OF LOAD
TEST – SENSOR PLAN
• Deflections in longitudinal and
transverse direction
• Vertical deflections at support
• Strain on bottom of concrete
• Opening of existing cracks
• Cracking activity with acoustic
emission sensors
• Load cells for applied loads

EXECUTION OF PROOF LOAD
TEST – LOADING PROTOCOL
• Test for bending moment and test for
shear
• Cyclic loading protocol
• Four load levels:
• Low load to check response of all
sensors
• Serviceability Limit State
• RBK Usage Level: maximum required
for assessment
• Eurocode Ultimate Limit State + 6%
(bending test) / + 2% (shear test)

EXECUTION OF PROOF LOAD
TEST – LOAD APPLICATION
• Load application:
counterweights on steel
spreader beam; load
transferred to bridge via jacks
• Controlled method for cyclic
loading
• Avoid collapse when large
deformations occur

EXECUTION OF PROOF LOAD
TEST – VERIFICATION OF
MEASUREMENTS
• Load-displacement diagram: check
for nonlinear behavior
• Maximum stiffness reduction:
• Bending moment test 16%
• Shear test 10%
• Residual deflection / maximum
deflection
• Bending moment test: 15%
• Shear test: 8%
• Limit ACI: 25%
• Limit DAfStB: 10%

• Video

ASSESSMENT OF VIADUCT
DE BEEK – SPAN 1
• Proof load test shows immediately that span fulfils
requirements of code
• No signs of distress observed from measurements
• Conclusion: UC ≤ 1.0

ASSESSMENT OF VIADUCT
DE BEEK – SPAN 2
• How to extrapolate results from
Span 1 to Span 2?
• Assessment with plastic
redistribution
• Plastic hinge develops in span 2
• Use 6.7% of plastic redistribution
• UC in span = 1.0
• UC over support 0.94

ASSESSMENT OF VIADUCT
DE BEEK -
RECOMMENDATIONS
• Verify reinforcement in
Span 2 with scanner
and/or by removing cover
• Check for signs of
corrosion
• Reopen for two lanes of
traffic

IABSE SYMPOSIUM ENGINEERING THE FUTURE SEPTEMBER 21-23, 2017
SUMMARY
• Proof load testing to approve existing bridges
• Case study: Viaduct De Beek
• Preparation of load test:
• Target proof load
• Sensor plan
• Execution of load test
• Cyclic loading protocol
• Jacks and steel spreader beam
• Real-time evaluation of measurements
• Analysis of load test
• Assessment of viaduct
• Reporting all results

Contact:
Eva Lantsoght
E.O.L.Lantsoght@tudelft.nl // elantsoght@usfq.edu.ec
+31(0)152787449