查看文章

The damage to flyovers caused by increasing traffic in last decade has demonstrated the need to assess the vibration on existing flyovers built before the advent of modern seismic design codes. The present study aims at the measurement of traffic flow and vibration characteristics on five different flyovers in Delhi (NCR). The traffic count was conducted manually; however, vibration characteristics of each flyover have been investigated using tri-axial accelerometer. The vibrations produced in flyovers have been recorded in all directions of space (X, Y, Z). Results show that vibrations produced in Panchsheel flyover have maximum vibration,(110.1 dB, 105.2 dB, and 113.2 dB) in X, Y, Z directions respectively, whereas Chirag Delhi flyover have minimum vibrations in all the three directions, ie,(74.3 dB, 73.4 dB, 74.5 dB). All four flyovers were coated with bitumen or asphalt and their spans were shorter as well, which helped in resisting vibrational shocks. Besides being too long panchsheel flyover may be due to its girder type construction and having no bituminous or asphalt coating as well as very large span, which helps in resisting the vibrational shocks.