01556702

Component

Consistent increases in cumulative freight tonnages, combined with the move towards higher-speed intercity passenger rail operation, have placed greater demands on North American railroad infrastructure. Concrete crossties and fastening system components are known to fail at a wide range of life cycle intervals when subjected to demanding loading environments. Such failures can cause track geometry defects, require repetitive maintenance procedures, and present critical engineering challenges. Rail seat deterioration (RSD), the degradation of the concrete material beneath the rail, has been identified through surveys of North American Class I railroads as the most critical engineering challenge of concrete crossties. Shoulder/fastener wear or fatigue was identified through the same survey as the second most critical engineering challenge related to concrete crossties. Lateral forces transferred through the fastening system are thought to be a primary cause of degradation of insulators. The objective of this study is to quantify the demands on the insulator through analysis of the transfer of lateral wheel loads into the fastening system by measuring the magnitude of lateral forces entering the shoulder, a component of the fastening system adjacent to the insulator. The Lateral Load Evaluation Device (LLED) was developed at University of Illinois at Urbana-Champaign (UIUC) to quantify these forces. Data captured by the LLED will assist the rail industry in moving towards the mechanistic design of future fastening systems by quantifying lateral forces in the fastening system under representative loading conditions. Information gained through this study will also lead to a better understanding of the frictional forces at key interfaces in the fastening system. Preliminary results show that the transfer of lateral wheel loads into the fastening system is highly dependent on the magnitude of lateral wheel loads and the frictional characteristics of the fastening system.

This paper was sponsored by TRB committee AR050 Railroad Track Structure System Design.

01550057

15-1534

English

14p

2015

Transportation Research Board 94th Annual Meeting

Digital/other

Figures; Photos; References

Axle load force; Concrete ties; Deterioration; Equipment design; Fastenings; Friction; Maintenance of way; Measurement; Railroad tracks

Lateral loads

Maintenance and Preservation; Railroads; Terminals and Facilities; I61: Equipment and Maintenance Methods

Transportation Research Board Annual Meeting 2015 Paper #15-1534

PRP, TRIS, TRB, ATRI

Dec 30 2014 12:34PM