Finite element model calibration of Babak bridge by dynamic load tests

Masonry bridges are an important asset of Iranian railway infrastructure. Their health monitoring is vital due to their long life in service. Also, there is a growing demand for higher traffic which requires the passage of higher axle loads over such bridges. Feasibility study of applying an increased axle load of 25 tons to an old masonry bridge is presented. Babak bridge is located in north western zone of Iranian railway network and has been in service for more than 70 years. The bridge is consists of stone segments, and has three long spans of 21.5 meters, 7 spans of 10 meters, and a total length of 270 meters. A finite element model of the bridge is developed in Abaqus software. Modeling the exact behavior of masonry bridges is difficult due to their complex structures, added the age of bridges which could not be integrated in numerical models. In this respect, field tests of Babak bridge have been designed to monitor the response of bridge subjected to predefined loading scheme by 17 sensors including deflection meters and accelerometers. A total of 37 tests are carried out on Babak bridge, and the results are used to calibrate the numerical model of the bridge. The numerical model is then used to determine the weak spots of bridge due to subjection of higher axle loads for a possible strengthening procedure

Keywords:

Masonry arch bridge , Field tests , ABAQUS , F.E. Model