Abstract

A number of rail embankments in Canada are constructed on land surfaces covered by organic soils such as peat. Peat soils are known to exhibit enormous deformation potential owing to their excessive water content with low strength. Because of this, railway embankments built on peat experience reoccurring problems of settlement and deformation. Consequently, this increases the cost of maintenance and impedes the safety and stability of a slope under moving freight train conditions. Thus, to stabilize the peat under the railway embankment, this research modeled the behavior and evaluated the effectiveness of driven wooden piles as a method of stabilization. Employing the finite element shear strength reduction (FE-SSR) method, the development of excess pore water pressure and settlement of 2-dimensional models are investigated thoroughly. Using the Biot’s consolidation theory, a coupled model providing an in-depth understanding of the mechanism of development of excess pore water pressure and stress essential for understanding the development of settlements is considered. Key factors such as geometric characteristics of the slope, wooden piles (length, diameter, and spacing), and freight train speeds were conducted through a series of parametric studies to ascertain their effects on embankment failure. A sensitivity analysis was introduced to individually investigate each parameter of the wooden piles and its effect on slope stability. Adopting a minimum factor of safety of 1.3, slopes with different geometric parameters and wooden piles, and maximum safe train speed is required to ensure the adequate performance of slopes considering the high compressibility nature of peat. The results illustrate that a slope with 2H:1V slope inclination exhibits a larger degree of settlement and deformation and a considerable increase in pore water pressure under a high-speed train load. Details of the maximum allowable speed a train can use, given the geometric parameters of the slope, railway embankment height, and wooden piles are finally presented in this study for safe freight train performance.