• Rahul A. Patil
• Pandurang S. Patil

The response of a box girder bridge under a moving vehicle at varying loading and varying speed is a multifaceted phenomenon because of the interface between the bridge and the vehicle. This intricate and daedal problem makes it difficult to identify the significant design parameters that govern the response, yet another crucial issue is knowledge of such design parameter and its parametric changes when varying loading, varying speed condition considered. Therefore, noticeable vibration of box girder bridges under live loads is an imperative design consideration in today’s bridges. Although with different design parameter, strength and deflection, acceleration, vehicle speed, vehicle weight criteria of these bridges are enclosed well, vehicle movement over the bridges still generates the vibrations in the box girder bridge structure. Identification of moving loads on a moving vehicle at varying loading and varying speed on bridges is a vital contrary tricky problem in the civil and structural engineering field. In this research study a numerical model is developed for studying bridge vehicle interface, study of parametric changes with consideration of varying mass and speed condition and endorsement of SAP 2000 results is done with FFT field test results. A parametric study is performed to identify the effects of various parameters such as speed of vehicle and weight of vehicle on the vibration of box girder bridge. This research work presents SAP 2000 software analysis of dynamic response of Vathar and Peth highway bridge at NH – 4 (Mumbai – Bengaluru highway) along with field testing of bridge by using accelerometer and FFT analyser. There are number of parameters which can affect the bridge vibrations such as bridge geometry, speed of vehicle, weight of vehicle, acceleration of vehicle and suspension system of vehicle, coarseness of pavement and bearing provided. Modelling along with all above said parameters makes it byzantine for analysis therefore dynamic behaviour made through numerical modelling may have some errors. FFT field tests under specified dynamic loads are steadfast means for evaluation of dynamic characteristics of bridges. With the help of this research work results of field tests on typical 30 m and 33 m simple span of box girder bridge are presented. It is an effective way to better understand the interaction between the bridge and vehicles crisscrossing it in order to achieve a reasonable lifecycle for the future box girder bridge design. This research work reviews the contemporary knowledge on factors affecting performance bridge under moving load and its effect identification methods under main headings below: background of moving loading condition and its effects identification, experimental validation in laboratory and its application in practical field. Although there are still so many intricate problem and hindrances to be overcome before these methods can be implemented in practice, some conclusions that have been achieved on moving loading vehicle with consideration of varying mass and speed condition, identification are highlight recommendations served as a good indicator to coxswain and steer the direction of further research work in the bridge design field.

Box girder bridges, Varying mass and speed condition, Moving load, Numerical model, FFT analyser and field test, SAP 2000 software analysis, dynamic response etc

"A Study and assessment of dynamic behaviour of existing bridge under vehicle load", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.6, Issue 6, page no.122-130, June 2019, Available :http://www.jetir.org/papers/JETIR1907615.pdf

"A Study and assessment of dynamic behaviour of existing bridge under vehicle load", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.6, Issue 6, page no. pp122-130, June 2019, Available at : http://www.jetir.org/papers/JETIR1907615.pdf