Rail anchors play a critical role in providing longitudinal track resistance and maintaining rail neutral temperature (RNT) in continuously welded rail (CWR) track. However, the slip behavior of drive-on rail anchors under realistic wear conditions and varying loading scenarios remains insufficiently quantified, limiting the ability to represent anchor performance accurately in mechanistic rail stress management and longitudinal resistance models.
This proposed research will conduct a controlled laboratory investigation to quantify the slip strength of drive-on rail anchors as a function of anchor and rail wear, loading rate, and reaction location. A force-controlled slip testing methodology, adapted from current recommended practice, will be implemented using a servo-hydraulic actuator, a representative 136RE rail segment, and configurable reaction blocks designed to simulate tie plate and crosstie boundary conditions. High-resolution displacement sensors will measure relative movement between the rail and anchor to capture slip initiation, progression, and ultimate strength.
The study will systematically evaluate how repeated anchor installations influence slip capacity, how wear conditions of both the rail and anchor affect resistance, and how loading rate—including quasi-static and impact scenarios—modifies slip behavior. Additional testing will examine the influence of reaction geometry on anchor rotation and walking mechanisms during slip events.
The expected outcome of this work is an improved understanding of the condition-dependent behavior of drive-on rail anchors and the mechanisms governing their slip resistance. Results will support the development of more representative anchor resistance parameters for use in mechanistic rail stress management, longitudinal track resistance modeling, and anchor design and maintenance strategies. Ultimately, this research will provide railroads with improved tools to evaluate anchoring effectiveness and better manage longitudinal rail forces in CWR track.