Investigating dynamic amplification factor of railway masonry arch bridges through dynamic load tests

Dynamic load testing has become a common practice for condition assessment of masonry arch bridges and lays the foundation for their rehabilitation procedures; however, additional dynamic testing after rehabilitation is rare. Carrying out dynamic load tests before and after rehabilitation programs produces valuable results with regard to the structural changes of the bridge. This paper tries to assess the effects of ballast cleaning on the performance of railway masonry arch bridges by conducting dynamic load tests before and after the rehabilitation procedure. To do so, a 70-year-old masonry arch bridge is instrumented with deflection meters and accelerometers. Dynamic load tests are carried out before and after ballast cleaning and results are compared. According to the test results, vertical deflections of different spots on the bridge remain the same, with a deviation of less than 5%. On the other hand, vibrations on the structure are reduced significantly. On average, vibration levels are reduced by 35% in different spots of the structure.

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Analysis of test blanket module attachments under electromagnetic loads by using a dynamic amplification factor envelope

Fusion Engineering and Design ◽

10.1016/j.fusengdes.2018.04.110 ◽

2018 ◽

Vol 136 ◽

pp. 1247-1251

Author(s):

Raúl Muñoz ◽

Francisco J. Calvo ◽

Sergio Sádaba ◽

Ana M. Gil ◽

Javier Rodríguez ◽

...

Keyword(s):

Amplification Factor ◽

Dynamic Amplification Factor ◽

Dynamic Amplification

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A Study on Dynamic Amplification Factor and Structure Parameter of Bridge Deck Pavement Based on Bridge Deck Pavement Roughness

Advances in Civil Engineering ◽

10.1155/2018/9810461 ◽

2018 ◽

Vol 2018 ◽

pp. 1-8

Author(s):

Fei Han ◽

Dan-hui Dan ◽

Hu Wang

Keyword(s):

Bridge Deck ◽

Amplification Factor ◽

Amplification Coefficient ◽

Dynamic Amplification Factor ◽

Vibration Load ◽

Pavement Roughness ◽

Composite Bridge ◽

Dynamic Amplification ◽

Cushion Layer ◽

Bridge Deck Pavement

In order to study the coupled influence of deck pavement roughness and velocity on dynamic amplification factor, a 2-DOF 1/4 vehicle model is employed to establish the vehicle-bridge-coupled vibration system. The random dynamic load of running vehicle simulated by software MATLAB is applied on bridge deck pavement (BDP) through ANSYS software. Besides, the influence of BDP parameters on control stress under static load and random vibration load is analyzed. The results show that if the surface of BDP is smooth, the dynamic magnification coefficient would first increase and then decrease with increasing of vehicle velocity and reach its maximum value when v = 20 m/s; if the surface of BDP is rough, the maximal and minimum values of the dynamic amplification coefficient (DAC) occur, respectively, when the velocity reaches 10 m/s and 15 m/s. For a composite bridge deck with the cushion layer, the thickness of asphalt pavement should be not too thick or thin and better to be controlled for about 10 cm; with the increasing of cushion layer thickness, the control stress of deck pavement is all decreased and show similar change regularity under effect of different loads. In view of self-weight of structure, the thickness of the cushion layer is recommended to be controlled for about 4 cm.

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