Research and analysis of the stressed-strained state of metal corrugated structures of railroad tracks

Abstract

We conducted research into, and analysis of, bearing capacity of metal corrugated structures (MCS), which are in service in the railroads of Ukraine. To assess the stressed-strained state of MCS, a calculation was carried out of equivalent forces that arise from the rolling stock when there is an irregularity in a railroad track, formed in the course of using a pipe. We ran analysis of the MCS bearing capacity at boundary load from the rolling stock of railroads by the indicator of influence of the type of corrugation (corrugattion dimensions) and characteristics of soils on their stressed-strained state. A calculation of equivalent forces was conducted by the method of calculation of a railroad track by strength and stability. A mathematical algorithm was programmed by the Peterson method to calculate the stressed-strained state of MCS. An analysis of multi-choice calculations of the MCS strength, which is made from the corrugated structure Multiplate MR150 with thickness of corrugated sheet 6 mm and dimensions of the corrugation waves 150 × 50 mm and 380 × 140 mm, demonstrated that its bearing capacity is provided. The degrees of compaction of the soil backfill are from 0.9 to 1.0. A metal corrugated structure that is made from corrugated sheets of size 200 × 55 mm, at the degree of compaction of the soil backfill 0.9, there occur stresses that exceed the permissible. Further accumulation of residual stresses from the action of dynamic wheel load, taking into account time parameter, may affect the occurrence of fluidity of material of a metal pipe. This may lead to the formation of its plastic irreversible deformations. Results of the MCS bearing capacity that we received are necessary for the optimal design of MCS, to establish the causes of occurrence of defects, to make timely relevant engineering decisions to increase bearing capacity of MCS and substantiate reasonable use of funds for the construction or renovation of existing transport facilities using metal corrugated pipes. These studies may be used by engineers at the bridge-testing stations of Ukrainian Railroads and Ukravtodor and by design organisations engaged in the design of metal corrugated structures of large diameters.