The New Jersey Institute of Technology's
Electronic Theses & Dissertations Project

Title:	Dynamic response of highway bridges under a moving truck and development of a rational serviceability requirement
Author:	Darjani, Shabnam
View Online:	njit-etd2013-027 (xxii, 164 pages ~ 5.7 MB pdf)
Department:	Department of Civil and Environmental Engineering
Degree:	Doctor of Philosophy
Program:	Civil Engineering
Document Type:	Dissertation
Advisory Committee:	Saadeghvaziri, M. Ala (Committee chair) Feizi, Bakhtiar (Committee member) Hsu, C.T. Thomas (Committee member) Navalurkar, Rajendra (Committee member) Schuring, John R. (Committee member) Wecharatana, Methi (Committee member)
Date:	2013-01
Keywords:	Highway bridge Dynamic response Moving load Acceleration and velocity Fatigue Human comfort
Availability:	Unrestricted
Abstract:	Through the development and usage of high-strength materials, the design of more flexible bridges is unavoidable. It is assumed that limiting a bridge static deflection would control the excessive vibration caused by more flexible design. However, results of prior studies indicate that deflection limits do not necessarily address bridges vibrational issue. This dissertation addresses the parameters affecting bridge vibration and provides simple equations to compute bridge dynamic acceleration, velocity and displacement in both transient and steady state parts of the vibration. These equations can then be used to control bridges excessive vibration; and provide human comfort and structural performance. A comprehensive analytical study was performed to evaluate dynamic response of bridges under a moving truck load. The effect of bridge dynamic parameters and vehicle moving conditions are investigated, which includes bridge frequency, damping ratio, span length, girders distance, bracing, support conditions, truck speed, load sequence, axle‘s weight, and number of spans. Bridge and vehicle k-parameters, which represent the number of vibration cycles before the next excitation occurs, are developed to better explain the vibrational behavior of a bridge. The proposed equations include bridge frequency, static deflection for one axle load, and k-parameters. Finally, a case study is presented to highlight the application of the new approach.