eurocodes for the assessment of the existing structures

Eurocodes for the assessment of the existing structures.

RWS Managing Contractor

Agenda:

1. Introduction� Bridges

� Defects

� Proposed Solution

2. Use of Eurocodes in Assessment.

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2. Use of Eurocodes in Assessment.� Lane arrangement

� Load Factors

� Reduction Factors

Introduction

� Joint Venture : Royal Haskoning, Arup, Greisch

� Client : Rijkwaterstaat

� 8 Major bridges in the Netherlands fatigue and strength issues

� Renovation over an 8 year programme

� To give 30 yrs. further useful life.

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� Concrete overlay already decided solution for fatigue

Bridges

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•Waalbrug Ewijk

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•Waalbrug Ewijk

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Defects

� Orthotropic Decks

� Fatigue Problems

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Proposed Solution

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Eurocodes

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National Annexes

Design Memos

Eurocodes used for the assessment:

� Eurocode 0: Basis of structural design - NEN1990

� Eurocode 1: Action on the structures - NEN1991

� Eurocode 2: Design of concrete structures - NEN1992

� Eurocode 3: Design of steel structures - NEN1993

� Eurocode 4: Design of composite steel and concrete structures

- NEN1994

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- NEN1994

Lane arrangement on the bridge:

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Lane arrangement on the bridge:

12.25 m

3.0 m 3.0 m 3.0 m 3.0 m

12.25 m

3.0 m 3.0 m 3.0 m 3.0 m

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3.0 m 3.0 m 3.0 m 3.0 m 3.0 m 3.0 m

Load Factors:

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Load Factors:

Action Default values

from Eurocode

Dutch National

Annex

Modified values for

assessment

Permanent Load 1.35 1.5 1.25 (6.10a)

1.10 (6.10b)

Variable Traffic

Load

1.35 1.5 1.10 (6.10a)

1.25 (6.10b)

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Other Variable Load 1.5 1.65 1.2 (6.10a)

1.5 (6.10b)

Reduction factors.

� Shortening of the reference design life

� Trend reduction in load magnitude

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Shortening of the reference design life:

0.96

1.0

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Reference period Reduction factor

100 years 1.00

15 years 0.95

1.0 years 0.88

Month 0.82

Trend reduction in live load magnitude:

Influence

length L

[m]

2000 2010 2020 2030 2040 2050

0 1.00 1.00 1.00 1.00 1.00 1.00

20 0.89 0.91 0.93 0.96 0.98 1.00

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50 0.82 0.86 0.89 0.93 0.96 1.00

75 0.78 0.83 0.87 0.91 0.96 1.00

100 0.76 0.81 0.85 0.90 0.95 1.00

150 0.75 0.80 0.85 0.90 0.95 1.00

200 0.75 0.80 0.85 0.90 0.95 1.00

Trend reduction in live load magnitude:

Influence

length L

[m]

2000 2010 2020 2030 2040 2050

0 1.00 1.00 1.00 1.00 1.00 1.00

20 0.89 0.91 0.93 0.96 0.98 1.00

30 years

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50 0.82 0.86 0.89 0.93 0.96 1.00

75 0.78 0.83 0.87 0.91 0.96 1.00

100 0.76 0.81 0.85 0.90 0.95 1.00

150 0.75 0.80 0.85 0.90 0.95 1.00

200 0.75 0.80 0.85 0.90 0.95 1.00

Reduction factors.

� Shortening of the reference design life

� Trend reduction in load magnitude

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DL+0.96 x 0.95 x LL

Thank You

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