3.1.1 The extent of local measurement should be set within
approximately 50 mm of each side of the baseline, as shown in Figure 1.
3.1.2 Within the extent of local measurement,
at least five points should be arranged, including one point on the
baseline and with approximately 25 mm spacing at maximum. Thereby,
the local thickness distribution for the deck plate can be obtained
for the target longitudinal.
3.1.3 From the measured thickness distribution, a
representative thickness diminution (Δt), defined by the following equation (1),
should be estimated from the measured data on the baseline and the minimum thickness
value among the other points:
|
= |
|
Where:
- t0: measured thickness on the baseline which is nearly equal to original
thickness minus corrosion diminution for deck upper surface (Δt) as shown in
figure 1;
- t1,t2,t3,t4: thickness on each
measuring point; and
- (Δt) : representative thickness diminution, which is assumed to be nearly
equal to the diminution of the fillet weld throat thickness.
3.1.4 An estimated residual throat thickness is
determined by:
|
Gresidual
|
= |
Goriginal - Δt |
where Goriginal is the original throat thickness at the weld.