Impact factor of moving load due to surface roughness of girder bridge of variable spa | |
| Author | Lee, Hee Hyun |
| Call Number | AIT Thesis no. ST-85-16 |
| Subject(s) | Bridges, Box girder Bridges--Live loads |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Engineering and Technology |
| Publisher | Asian Institute of Technology |
| Abstract | The vehicle-induced dynamic response of a simply supported bridge with a rough pavement is analysed. The bridge response of a vehicle moving at constant speed over a rough and smooth deck, the effects of vehicle braking, and the effects of traffic composition are discussed. Impact factors for deflection, bending moment and shear force are determined for bridges with spans ranging from 25 to 100m. The bridge is modelled by finite elements assuming lumped masses. The vehicle is idealized as an unsprang single point load and bridge surface roughness is characterized by a random vehicle-pavement interactive force which satisfies a prescribed power density function. the response of the bridge is determined using a direct integration method. For verification and optimum selection of the discretized model, the numerical results for a bridge with smooth surface were checked with the analytical solution derived by Timoshenko. Fifteen sets of vehicle-pavement interactive force time histories are generated artificially in order to simulate the effect of pavement roughness. From a statistical analysis of the corresponding maximum dynamic responses, impact factors for deflection, bending moment and shear force are calculated. The impact factors resulting from different vehicle speeds, span lengths, and pavement properties (smooth, rough) are compared with those given in a number of bridge codes. Impact factors for the deflection are decreasing with increasing span length but this is not the case for moments and shear forces. The impact factors obtained from the simulation analysis are larger than those specified in codes. |
| Year | 1985 |
| Type | Thesis |
| School | School of Engineering and Technology (SET) |
| Department | Other Field of Studies (No Department) |
| Academic Program/FoS | Structural Engineering (STE) /Former Name = Structural Engineering and Construction (ST) |
| Chairperson(s) | Wireland, Martin |
| Examination Committee(s) | Brotton, Derick M. ; Karasudhi, Pisidhi |
| Scholarship Donor(s) | The Royal Netherlands Government |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1985 |