PSI - Issue 52

Govardhan Polepally et al. / Procedia Structural Integrity 52 (2024) 487–505 Govardhan Polepally/ Structural Integrity Procedia 00 (2019) 000 – 000

504 18

Table 13. Difference between Numerical and experimental results Bridge 1 Bridge 2 Bridge 3

Bridge 4

Bridge 5

Frequencies (Hz)

Difference

Difference

Difference

Difference

Difference

Mode 1 Mode 2 Mode 3 Mode 4 Mode 5 Mode 6 Mode 7 Mode 8 Mode 9 Mode 10 Mode 11 Mode 12 Mode 13 Mode 14 Mode 15 Mode 16 Mode 17 Mode 18 Mode 19 Mode 20

57.1 19.0 23.1 12.3 15.9 11.5 17.8 17.1 14.9 17.2 13.6 10.3

3.4

0.8

57.9 56.2 58.7 42.4 54.5 44.8 43.6 32.0 30.8 30.5 26.9 29.5 25.4 22.7 26.1 39.1 42.2 39.2 38.7 27.2

1.0 7.2 8.8 3.5

-3.5

12.9 16.3 15.0 32.1 32.5 26.5 26.8 23.8 30.9 33.3 33.0 31.2 49.3 46.1 45.0 41.3 45.0 47.0 43.4

-12.0 -10.4 -11.2

21.2 17.0 11.5 13.3 11.6 13.8 14.5 12.8 23.8 25.8 27.2 24.7 26.3 29.6 26.1 5.3

-8.0 -3.6 -0.3 -3.9 -1.6 -1.9 -3.8 -5.5 -7.9 -8.8 -9.2

7.4 2.5 2.3 5.5 7.2 1.9 1.1 1.8

-12.9 -11.8 -15.8 -19.8

5. Conclusion For reasonable and cost-effective maintenance of damaged bridges, evaluating the LCC of existing bridges is crucial. However, traditional static load testing is often considered expensive and labor-intensive, limiting its widespread implementation. To address this, a study proposes an effective approach for determining the LCC of existing bridges using Vibration analysis twinning with the Numerical model. The technique involves two primary steps, firstly, testing the approach through numerical simulations using a three-dimensional finite element model of a representative bridge under moving loads, and secondly, confirming the method using experimentally collected acceleration data transformed into frequencies. During visual inspections of five bridges, several defects were identified, primarily related to minor cracks, spalled concrete, exposed reinforcement, and vegetation growth. These issues have the potential to cause corrosion, debris accumulation, and further structural damage, underscoring the importance of timely maintenance and repairs. Promptly addressing these problems is crucial to ensure the structural integrity of the bridges, and regular inspections should be conducted to prevent similar issues from arising in the future. Analyzing the Non-Destructive Testing (NDT) results presented in Tables 2-6 for the five bridges, it can be concluded that the concrete quality used in the Reinforced Cement Concrete (RCC) structures of all the bridges has in the range of good to very good. The Ultrasonic Pulse Velocity (UPV) and Rebound Hammer (RH) tests conducted at the maximum tested locations of the RCC structures indicate a good quality grading. Results from the Half Cell Potential test suggest a 90% probability of no corrosion or uncertainty regarding the possibility of corrosion in all the bridges. Furthermore, the average compressive strength of the RCC Pier walls for all the bridges ranges from 28.19