Research Output

Continuous surface wave and impact methods of measuring the stiffness and density of railway ballast.

  Continuous surface wave and transient impact excitation tests were performed on strips of ballast to monitor their compaction. The ballast's shear wave velocity, hence the ratio of its shear modulus and density, increased with depth. Two types of transient excitation tests were carried out: firstly an impact load was applied to the ballast and the resulting transient acceleration measured at various positions. Secondly, two accelerometers at different distances from the impact excitation were used to study the effects of compaction on the transient output signal amplitude and its attenuation. Measured shear wave velocities showed good correlation between amount of compactive effort and ballast stiffness.

Citation

Zagyapan, M. & Fairfield, C. A. (2002). Continuous surface wave and impact methods of measuring the stiffness and density of railway ballast. NDT and E International. 35, 75-81. doi:10.1016/S0963-8695(01)00034-2. ISSN 0963-8695

Keywords

Railway ballast; Compaction; Density; Measurements; Field inspection; Effects; Shear waves; Impacts; Pulse echoes; Railway engineering;

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