PSI - Issue 64

Pat Rajeev et al. / Procedia Structural Integrity 64 (2024) 523–530 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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specimen. Thus, only inspecting a 300-400 mm below ground section of an anchor rod may not provide any reasonable assessment of the severity of below ground corrosion of a cable stay. Assessment of the bed log condition was useful in correlating the corrosion levels at the anchoring region of the steel rod. Higher corrosion rates were observed with the presence of degraded and wet bed logs in comparison with sound dry bed logs.

(b)

(a)

Fig. 4. Excavation to uproot cable stays (a) excavation (b) bed log anchor

Table 1. Details of uprooted cable stays and visual inspection results Specim en ID Installat ion year Diameter (mm)

Stay size (mm)

Coating thicknes s (µm)

% Reducti on in cross section

Corrosi on category

Anchor type

Bed log condition

Above ground

With in 300 mm below ground

At the bottom

1 2 3 4 5 6

1964 1964 1993 1964 1980 1981

24 19 19 19 24 24

114 112 127 126 125 122

24.42 20.08 19.05 20.42 24.23 24.39

24.13 18.86 19.01 19.95 24.21 24.10

23.85 20.00 18.94 18.86 23.58 23.44

4.61

3 2 3 2 1 1

Bed log

Dry bed log

11.78

Rock

-

1.15

Bed log Bed log Bed log Bed log

Dry bed log

14.69

Highly degraded bed log

5.29 7.64

Dry bed log

Severely degraded bed log Bed log with signs of internal degradation

7

1985

24

126

24.66

24.52

24.08

4.65

1

Bed log

8

1986

24

120

24.38

24.36

22.79

12.62

1

Bed log

Dry bed log (no degradation)

9

1986

24

119

24.17

24.08

23.58

4.82

2

Bed log

Seem to be a dry bed log Severely degraded bed log

10

1986

24

134

24.4

24.36

23.66

5.97

1

Bed log

11 12

1981 1981

24 24

112 108

24.21 24.25

24.16 24.17

24.06 23.76

1.24 4.00

3 2

Screw

-

Bed log

Dry bed log (no degradation)

13

1976

24

121

24.37

23.99

24.27

3.09

3

Bed log

Dry bed log (externally degraded) Dry bed log (slight degradation)

14

1993

24

118

24.10

24.06

23.79

2.56

2

Bed log