சி. எஸ். ஐ. ஆர். - கட்டமைப்பு பொறியியல் ஆராய்ச்சி நடுவம்

In order to estimate reliably the distribution of longitudinal force induced on the bridge, a scheme was devised for calibration of longitudinal force transferred from rail to girder. The test setup developed as shown in Fig. 1a for assessing the distribution of longitudinal force consists of two parts- (i) force-generating part and (ii) reaction system part. Force generating part (jacking end) was positioned on the span which is sufficiently away from the instrumented span of the bridge, and the reaction system was placed on the instrumented span of the bridge. From the data obtained in the above mentioned test, it has been noted that the output from strain gages used for measuring the longitudinal strain at mid depth is very small. Using the output from the channel for bending strain at mid span, percentage of applied longitudinal force that is transferred to the girder is evaluated. The methodology devised for calibration, to assess distribution/dispersion of longitudinal force from rail to the bridge and evaluation of longitudinal force induced on the bridge girder due to different load levels and train formations, would help to assess the adequacy of the existing bridges.