PSI - Issue 18

Muhammad Fawad et al. / Procedia Structural Integrity 18 (2019) 189–197 M. Fawad/ Structural Integrity Procedia 00 (2019) 000–000

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plates of 2.71m length along the sidewall, 28 plates of 7m length at the bottom plate and 8 plates of 2m length at the centre. These steel plates are introduced as a new material in ATENA and properties of these plates has been used as the material properties. 3, 4, 5 and 6mm thick plates are available in the market. So the thickness of the plate can be calculated by using the thickness formula of (0.005/0.007)d. As a result, steel plate of 5mm is used for this strengthening. Epoxy resin is used as an adhesive agent for plate and concrete connection. This connection has been modelled as a new material, “3D-Interface” in ATENA and connection between the macro elements of steel plates is set according to this material. Thickness of this adhesive agent layer is set to the half of the thickness of steel plate which is (5/2=2.5mm). 3.1.1. Deflection Deflection value along x-axis obtained after the analysis are shown in the table 1, which shows that deflection has been reduced a lot due to application of retrofitting using steel plates.

Table 1- Deflection Values after Steel Plate Strengthening

Section I & II

Z3 (Z-axis)

Critical Max (mm) Critical Min (mm)

3.37 -0.31

3.1.2. Cracks Total Area of cracked region = (22.08+31.76+12.4) = 66.24 m²/span= 66.24/414= 16%

Percentage of cracks show that the overall cracked area has been reduced from 30% to 16 %. Now the most critical parameter is the crack width because the bridge was not satisfying the allowable crack width limit. After the strengthening, it has been observed that the critical crack width at the central support has reached to 0.237mm (Figure 8). Critical crack width has been reduced from 0.61mm to 0.237mm (table 2), which is although, less than the allowable limit of 0.3mm but very close to it. So further improvement is required.

Figure 2. Critical Crack Width-Steel Plate Strengthening

Table 2- Critical Crack Width Values

Section I & II

(mm)

Critical Crack width

0.237

Normal crack width (mm)

0.02