Corrugated Steel Plate Culvert Response to Service Train Loads

This paper presents the results and conclusions of field tests under service loads that were conducted on a corrugated steel plate (CSP) railway culvert. Inductive gauges, extensometers, and accelerometers were used to monitor displacements, strains, and accelerations of this culvert, respectively. The maximum displacement and strain of the CSP railway culvert was -0.61x10-3m and -54x10-6, respectively. The biggest displacements and strains were recorded at the culvert crown and quarter points, respectively. The maximum culvert and ballast accelerations were equal to 0.67and1.23m/s2, respectively, and they did not exceed the Eurocode limit of 3.5m/s2. On the basis of the measured displacements, a discrete Fourier transform method was implemented to determine the frequencies of this culvert. The natural frequencies of the culvert were identified (using the ambient vibration test), and they corresponded to approximately two first dominant frequencies extracted from the forced vibration tests. The damping ratios were about 9% (using the ambient vibration test) and 50% (the forced vibration test). The axial thrusts and bending moments of the culvert were calculated based on the measured strains and by using the Sundquist-Pettersson method. The expected internal forces were much higher than those calculated on the basis of the experimental data. The distribution of axial thrusts and bending moments at the circumferential direction of the culvert is strongly asymmetric, which demonstrates the uneven distribution of loads. This is contrary to the available (American and Australian) standards in which the railway load is assumed as a uniform pressure at the level of the culvert crown. Conclusions drawn from the tests can be helpful in the assessment of the dynamic behavior of such CSP culverts.