Reliability Analysis of Prestressed Concrete Box Girder Bridges in California

Abstract

Truck traffic increases day by day according to the economy. Road network infrastructure has to meet this growing demand. This work focuses on prestressed concrete box girder bridges in California, because many signs of deterioration, such as cracks, have been observed lately. The objective is to calculate the reliability index for a wide spectrum of those bridges. There are over 6,000 prestressed concrete box girder bridges in California, and fourteen of them were selected for the reliability analysis. Moments due to dead load, live load and resistance were calculated, and the Monte Carlo method was used to calculate the reliability indices for the ultimate limit state. The average and standard deviation for the reliability indices are 4.81 and 1.38, respectively. Results show that the reliability indices for simple spans decrease and then increase as the span length and the load effect increase, increasing and then decreasing for continuous spans.